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Sample records for n-dimensional intrinsically universal

  1. Intrinsic Changes: Energy Saving Behaviour among Resident University Students

    ERIC Educational Resources Information Center

    Black, Rosemary; Davidson, Penny; Retra, Karen

    2010-01-01

    This paper presents the results of a study that explored the effectiveness of three intervention strategies in facilitating energy saving behaviour among resident undergraduate university students. In contrast to a dominant practice of motivating with rewards or competition this study sought to appeal to students' intrinsic motivations. An…

  2. Intrinsic universality and the computational power of self-assembly.

    PubMed

    Woods, Damien

    2015-07-28

    Molecular self-assembly, the formation of large structures by small pieces of matter sticking together according to simple local interactions, is a ubiquitous phenomenon. A challenging engineering goal is to design a few molecules so that large numbers of them can self-assemble into desired complicated target objects. Indeed, we would like to understand the ultimate capabilities and limitations of this bottom-up fabrication process. We look to theoretical models of algorithmic self-assembly, where small square tiles stick together according to simple local rules in order to carry out a crystal growth process. In this survey, we focus on the use of simulation between such models to classify and separate their computational and expressive powers. Roughly speaking, one model simulates another if they grow the same structures, via the same dynamical growth processes. Our journey begins with the result that there is a single intrinsically universal tile set that, with appropriate initialization and spatial scaling, simulates any instance of Winfree's abstract Tile Assembly Model. This universal tile set exhibits something stronger than Turing universality: it captures the geometry and dynamics of any simulated system in a very direct way. From there we find that there is no such tile set in the more restrictive non-cooperative model, proving it weaker than the full Tile Assembly Model. In the two-handed model, where large structures can bind together in one step, we encounter an infinite set of infinite hierarchies of strictly increasing simulation power. Towards the end of our trip, we find one tile to rule them all: a single rotatable flipable polygonal tile that simulates any tile assembly system. We find another tile that aperiodically tiles the plane (but with small gaps). These and other recent results show that simulation is giving rise to a kind of computational complexity theory for self-assembly. It seems this could be the beginning of a much longer journey

  3. n-dimensional FLRW quantum cosmology

    NASA Astrophysics Data System (ADS)

    Letelier, Patricio S.; Pitelli, João Paulo M.

    2010-11-01

    We introduce the formalism of quantum cosmology in a Friedmann-Lemaître-Robertson-Walker (FLRW) universe of arbitrary dimension filled with a perfect fluid with p=αρ equation of state. First we show that the Schutz formalism, developed in four dimensions, can be extended to a n-dimensional universe. We compute the quantum representant of the scale factor a(t), in the Many-Worlds, as well as, in the de Broglie-Bohm interpretation of quantum mechanics. We show that the singularities, which are still present in the n-dimensional generalization of FLRW universe, are excluded with the introduction of quantum theory. We quantize, via the de Broglie-Bohm interpretation of quantum mechanics, the components of the Riemann curvature tensor in a tetrad basis in a n-dimensional FLRW universe filled with radiation (p=(1)/(n-1)ρ). We show that the quantized version of the Ricci scalar are perfectly regular for all time t. We also study the behavior of the energy density and pressure and show that the ratio ⟨p⟩L/⟨ρ⟩L tends to the classical value 1/(n-1) only for n=4, showing that n=4 is somewhat privileged among the other dimensions. Besides that, as n→∞, ⟨p⟩L/⟨ρ⟩L→1.

  4. The Law of Cosines for an "n"-Dimensional Simplex

    ERIC Educational Resources Information Center

    Ding, Yiren

    2008-01-01

    Using the divergence theorem technique of L. Eifler and N.H. Rhee, "The n-dimensional Pythagorean Theorem via the Divergence Theorem" (to appear: Amer. Math. Monthly), we extend the law of cosines for a triangle in a plane to an "n"-dimensional simplex in an "n"-dimensional space.

  5. Emotional Creativity as Predictor of Intrinsic Motivation and Academic Engagement in University Students: The Mediating Role of Positive Emotions

    PubMed Central

    Oriol, Xavier; Amutio, Alberto; Mendoza, Michelle; Da Costa, Silvia; Miranda, Rafael

    2016-01-01

    Objective: Emotional creativity (EC) implies experiencing a complex emotional life, which is becoming increasingly necessary in societies that demand innovation and constant changes. This research studies the relation of EC as a dispositional trait with intrinsic motivation (IM) and academic engagement (AE). Methods: A sample of 428 university Chilean students, 36.5% men and 63.5% women, with ages from 18 to 45 years-old (M = 20.37; DT = 2.71). Additionally, the mediating function of class-related positive emotions in this relation is explored. Results: The obtained data indicate that developing high levels of dispositional EC enhances the activation of positive emotions, such as gratitude, love and hope, in the classroom. Furthermore, EC predicts IM and AE of university students by the experience of positive emotions. Conclusion: These results compel us to be aware of the importance that university students can understand the complexity of the emotional processes they undergo. A greater control of these emotions would allow students to maintain higher levels of interest in their studies at the different educational stages and to avoid the risk of school failure. PMID:27610091

  6. Emotional Creativity as Predictor of Intrinsic Motivation and Academic Engagement in University Students: The Mediating Role of Positive Emotions

    PubMed Central

    Oriol, Xavier; Amutio, Alberto; Mendoza, Michelle; Da Costa, Silvia; Miranda, Rafael

    2016-01-01

    Objective: Emotional creativity (EC) implies experiencing a complex emotional life, which is becoming increasingly necessary in societies that demand innovation and constant changes. This research studies the relation of EC as a dispositional trait with intrinsic motivation (IM) and academic engagement (AE). Methods: A sample of 428 university Chilean students, 36.5% men and 63.5% women, with ages from 18 to 45 years-old (M = 20.37; DT = 2.71). Additionally, the mediating function of class-related positive emotions in this relation is explored. Results: The obtained data indicate that developing high levels of dispositional EC enhances the activation of positive emotions, such as gratitude, love and hope, in the classroom. Furthermore, EC predicts IM and AE of university students by the experience of positive emotions. Conclusion: These results compel us to be aware of the importance that university students can understand the complexity of the emotional processes they undergo. A greater control of these emotions would allow students to maintain higher levels of interest in their studies at the different educational stages and to avoid the risk of school failure.

  7. Some properties of n-dimensional triangulations

    NASA Technical Reports Server (NTRS)

    Lawson, C. L.

    1985-01-01

    A number of mathematical results relevant to the problem of constructing a triangulation, i.e., a simplicial tessellation, of the convex hull of an arbitrary finite set of points in n-space are described. The principal results achieved are: (1) a set of n+2 points in n-space may be triangulated in at most 2 different ways; (2) the sphere test defined in this report selects a preferred one of these two triangulations; (3) a set of parameters is defined that permits the characterization and enumeration of all sets of n+2 points in n-space that are significantly different from the point of view of their possible triangulation; (4) the local sphere test induces a global sphere test property for a triangulation; and (5) a triangulation satisfying the global sphere property is dual to the n-dimensional Dirichlet tesselation, i.e., it is a Delaunay triangulation.

  8. NDF: Extensible N-dimensional Data Format Library

    NASA Astrophysics Data System (ADS)

    Warren-Smith, Rodney F.; Berry, David S.; Jenness, Tim; Draper, Peter W.

    2014-11-01

    The Extensible N-Dimensional Data Format (NDF) stores bulk data in the form of N-dimensional arrays of numbers. It is typically used for storing spectra, images and similar datasets with higher dimensionality. The NDF format is based on the Hierarchical Data System (HDS) and is extensible; not only does it provide a comprehensive set of standard ancillary items to describe the data, it can also be extended indefinitely to handle additional user-defined information of any type. The NDF library is used to read and write files in the NDF format. It is distributed with the Starlink software (ascl:1110.012).

  9. Quantum Discord of 2 n -Dimensional Bell-Diagonal States

    NASA Astrophysics Data System (ADS)

    Jafarizadeh, M. A.; Karimi, N.; Amidi, D.; Zahir Olyaei, H.

    2016-03-01

    In this study, using the concept of relative entropy as a distance measure of correlations we investigate the important issue of evaluating quantum correlations such as entanglement, dissonance and classical correlations for 2 n -dimensional Bell-diagonal states. We provide an analytical technique, which describes how we find the closest classical states(CCS) and the closest separable states(CSS) for these states. Then analytical results are obtained for quantum discord of 2 n -dimensional Bell-diagonal states. As illustration, some special cases are examined. Finally, we investigate the additivity relation between the different correlations for the separable generalized Bloch sphere states.

  10. Comparison of Intrinsic and Extrinsic Job-Related Factors among Assistant Coaches Employed in Predominantly White and Black Universities.

    ERIC Educational Resources Information Center

    Evans, Virden; And Others

    Comparison was made of the job attitudes of assistant coaches employed in predominantly white and black universities to determine the following job-related factors: (1) professional recognition; (2) personal initiative; (3) personal satisfaction; (4) job security; (5) salary; and (6) racial balance. Responses to a questionnaire were received from…

  11. n-dimensional generalizations of the Friedmann Robertson Walker cosmology

    NASA Astrophysics Data System (ADS)

    Garcia, Alberto A.; Carlip, Steve

    2007-02-01

    Within the n-dimensional spatially flat Friedmann Robertson Walker cosmology, determined for a single scalar field minimally coupled to gravity, we derive the n-dimensional Lucchin Mataresse (LM), Barrow Burd Lancaster Madsen (BBLM), and Barrow Saich (BS) cosmological solutions. No matter the dimensions one is dealing with, the potentials follow patterns similar to those ones of the corresponding standard 4-dimensional case; the self interacting potential for the n-LM inflationary model exhibits an exponential slow roll behavior as function of the scalar field, the potential of the n-BBLM model presents a Mexican-hat shape, while the potential for the n-BS cosmology, allowing for the simultaneous presence of a matter perfect fluid and a scalar field, follows a squared cosecant hyperbolic pattern.

  12. n-dimensional Statistical Inverse Graphical Hydraulic Test Simulator

    SciTech Connect

    2012-09-12

    nSIGHTS (n-dimensional Statistical Inverse Graphical Hydraulic Test Simulator) is a comprehensive well test analysis software package. It provides a user-interface, a well test analysis model and many tools to analyze both field and simulated data. The well test analysis model simulates a single-phase, one-dimensional, radial/non-radial flow regime, with a borehole at the center of the modeled flow system. nSIGHTS solves the radially symmetric n-dimensional forward flow problem using a solver based on a graph-theoretic approach. The results of the forward simulation are pressure, and flow rate, given all the input parameters. The parameter estimation portion of nSIGHTS uses a perturbation-based approach to interpret the best-fit well and reservoir parameters, given an observed dataset of pressure and flow rate.

  13. n-dimensional Statistical Inverse Graphical Hydraulic Test Simulator

    2012-09-12

    nSIGHTS (n-dimensional Statistical Inverse Graphical Hydraulic Test Simulator) is a comprehensive well test analysis software package. It provides a user-interface, a well test analysis model and many tools to analyze both field and simulated data. The well test analysis model simulates a single-phase, one-dimensional, radial/non-radial flow regime, with a borehole at the center of the modeled flow system. nSIGHTS solves the radially symmetric n-dimensional forward flow problem using a solver based on a graph-theoretic approach.more » The results of the forward simulation are pressure, and flow rate, given all the input parameters. The parameter estimation portion of nSIGHTS uses a perturbation-based approach to interpret the best-fit well and reservoir parameters, given an observed dataset of pressure and flow rate.« less

  14. Intrinsic formulation of the equation of Szebehely

    NASA Astrophysics Data System (ADS)

    Puel, F.

    1984-03-01

    The first-order linear partial differential equation developed by Szebehely (1974) for the potentials generating one-given-parameter family of plane orbits, expanded by Broucke (1980), Mertens (1981), and Erdi (1982) to the 3D case, is investigated analytically. An intrinsic formulation permitting the use of various coordinate systems is obtained for the plane case, and analogous techniques are applied in separate treatments of the 3D and N-dimensional cases.

  15. Methods, apparatuses, and computer-readable media for projectional morphological analysis of N-dimensional signals

    DOEpatents

    Glazoff, Michael V.; Gering, Kevin L.; Garnier, John E.; Rashkeev, Sergey N.; Pyt'ev, Yuri Petrovich

    2016-05-17

    Embodiments discussed herein in the form of methods, systems, and computer-readable media deal with the application of advanced "projectional" morphological algorithms for solving a broad range of problems. In a method of performing projectional morphological analysis, an N-dimensional input signal is supplied. At least one N-dimensional form indicative of at least one feature in the N-dimensional input signal is identified. The N-dimensional input signal is filtered relative to the at least one N-dimensional form and an N-dimensional output signal is generated indicating results of the filtering at least as differences in the N-dimensional input signal relative to the at least one N-dimensional form.

  16. t-topology on the n-dimensional Minkowski space

    SciTech Connect

    Agrawal, Gunjan; Shrivastava, Sampada

    2009-05-15

    In this paper, a topological study of the n-dimensional Minkowski space, n>1, with t-topology, denoted by M{sup t}, has been carried out. This topology, unlike the usual Euclidean one, is more physically appealing being defined by means of the Lorentzian metric. It shares many topological properties with similar candidate topologies and it has the advantage of being first countable. Compact sets of M{sup t} and continuous maps into M{sup t} are studied using the notion of Zeno sequences besides characterizing those sets that have the same subspace topologies induced from the Euclidean and t-topologies on n-dimensional Minkowski space. A necessary and sufficient condition for a compact set in the Euclidean n-space to be compact in M{sup t} is obtained, thereby proving that the n-cube, n>1, as a subspace of M{sup t}, is not compact, while a segment on a timelike line is compact in M{sup t}. This study leads to the nonsimply connectedness of M{sup t}, for n=2. Further, Minkowski space with s-topology has also been dealt with.

  17. SEnD NMR: Sensitivity Enhanced n-Dimensional NMR

    PubMed Central

    Gledhill, John M.; Wand, A. Joshua

    2009-01-01

    Sparse sampling offers tremendous potential for overcoming the time limitations imposed by traditional Cartesian sampling of indirectly detected dimensions of multidimensional NMR data. However, in many instances sensitivity rather than time remains of foremost importance when collecting data on protein samples. Here we explore how to optimize the collection of radial sampled multidimensional NMR data to achieve maximal signal-to-noise. A method is presented that exploits a rigorous definition of the minimal set of radial sampling angles required to resolve all peaks of interest in combination with a fundamental statistical property of radial sampled data. The approach appears general and can achieve a substantial sensitivity advantage over Cartesian sampling for the same total data acquisition time. Termed Sensitivity Enhanced n-Dimensional or SEnD NMR, the method involves three basic steps. First, data collection is optimized using routines to determine a minimal set of radial sampling angles required to resolve frequencies in the radially sampled chemical shift evolution dimensions. Second, appropriate combinations of experimental parameters (transients and increments) are defined by simple statistical considerations in order to optimize signal-to-noise in single angle frequency domain spectra. Finally, the data is processed with a direct multidimensional Fourier transform and a statistical artifact and noise removal step is employed. PMID:20004602

  18. N-dimensional hypervolumes to study stability of complex ecosystems

    PubMed Central

    Barros, Ceres; Thuiller, Wilfried; Georges, Damien; Boulangeat, Isabelle; Münkemüller, Tamara

    2016-01-01

    Although our knowledge on the stabilising role of biodiversity and on how it is affected by perturbations has greatly improved, we still lack a comprehensive view on ecosystem stability that is transversal to different habitats and perturbations. Hence, we propose a framework that takes advantage of the multiplicity of components of an ecosystem and their contribution to stability. Ecosystem components can range from species or functional groups, to different functional traits, or even the cover of different habitats in a landscape mosaic. We make use of n-dimensional hypervolumes to define ecosystem states and assess how much they shift after environmental changes have occurred. We demonstrate the value of this framework with a study case on the effects of environmental change on Alpine ecosystems. Our results highlight the importance of a multidimensional approach when studying ecosystem stability and show that our framework is flexible enough to be applied to different types of ecosystem components, which can have important implications for the study of ecosystem stability and transient dynamics. PMID:27282314

  19. Intrinsic Motivation in Physical Education

    ERIC Educational Resources Information Center

    Davies, Benjamin; Nambiar, Nathan; Hemphill, Caroline; Devietti, Elizabeth; Massengale, Alexandra; McCredie, Patrick

    2015-01-01

    This article describes ways in which educators can use Harter's perceived competence motivation theory, the achievement goal theory, and self-determination theory to develop students' intrinsic motivation to maintain physical fitness, as demonstrated by the Sound Body Sound Mind curriculum and proven effective by the 2013 University of…

  20. Critical probability of percolation over bounded region in N-dimensional Euclidean space

    NASA Astrophysics Data System (ADS)

    Roubin, Emmanuel; Colliat, Jean-Baptiste

    2016-03-01

    Following Tomita and Murakami (Research of Pattern Formation ed R Takaki (Tokyo: KTK Scientific Publishers) pp 197-203) we propose an analytical model to predict the critical probability of percolation. It is based on the excursion set theory which allows us to consider N-dimensional bounded regions. Details are given for the three-dimensional (3D) case and statistically representative volume elements are calculated. Finally, generalisation to the N-dimensional case is made.

  1. Geometric intrinsic symmetries

    SciTech Connect

    Gozdz, A. Szulerecka, A.; Pedrak, A.

    2013-08-15

    The problem of geometric symmetries in the intrinsic frame of a many-body system (nucleus) is considered. An importance of symmetrization group notion is discussed. Ageneral structure of the intrinsic symmetry group structure is determined.

  2. What Does it Mean to be a Christian? Exploring the Religious Identity of Intrinsically and Extrinsically Religious Black Seventh-Day Adventist University Students

    ERIC Educational Resources Information Center

    Ramirez, Octavio; Ashley, George; Cort, Malcolm

    2014-01-01

    This study explored the religious identity of Black Seventh-day Adventist University students and the elements that helped form their religious identity. The unidirectional, bidirectional and channeling models of socialization was used to describe the formation of religious identity. The data were collected in two stages. At the first stage, a…

  3. Intrinsic Analysis Training Manual.

    ERIC Educational Resources Information Center

    Gow, Doris T.

    This manual is for the training of linking agents between Education R&D and schools and for training teachers in the process of intrinsic analysis of curriculum materials. Intrinsic analysis means analysis of the instruction or process through examination of the materials, or artifacts, including teacher and student materials, developer's…

  4. Possibilities of identifying cyber attack in noisy space of n-dimensional abstract system

    NASA Astrophysics Data System (ADS)

    Jašek, Roman; Dvořák, Jiří; Janková, Martina; Sedláček, Michal

    2016-06-01

    This article briefly mentions some selected options of current concept for identifying cyber attacks from the perspective of the new cyberspace of real system. In the cyberspace, there is defined n-dimensional abstract system containing elements of the spatial arrangement of partial system elements such as micro-environment of cyber systems surrounded by other suitably arranged corresponding noise space. This space is also gradually supplemented by a new image of dynamic processes in a discreet environment, and corresponding again to n-dimensional expression of time space defining existence and also the prediction for expected cyber attacksin the noise space. Noises are seen here as useful and necessary for modern information and communication technologies (e.g. in processes of applied cryptography in ICT) and then the so-called useless noises designed for initial (necessary) filtering of this highly aggressive environment and in future expectedly offensive background in cyber war (e.g. the destruction of unmanned means of an electromagnetic pulse, or for destruction of new safety barriers created on principles of electrostatic field or on other principles of modern physics, etc.). The key to these new options is the expression of abstract systems based on the models of microelements of cyber systems and their hierarchical concept in structure of n-dimensional system in given cyberspace. The aim of this article is to highlight the possible systemic expression of cyberspace of abstract system and possible identification in time-spatial expression of real environment (on microelements of cyber systems and their surroundings with noise characteristics and time dimension in dynamic of microelements' own time and externaltime defined by real environment). The article was based on a partial task of faculty specific research.

  5. Genetic Algorithm for Optimization: Preprocessing with n Dimensional Bisection and Error Estimation

    NASA Technical Reports Server (NTRS)

    Sen, S. K.; Shaykhian, Gholam Ali

    2006-01-01

    A knowledge of the appropriate values of the parameters of a genetic algorithm (GA) such as the population size, the shrunk search space containing the solution, crossover and mutation probabilities is not available a priori for a general optimization problem. Recommended here is a polynomial-time preprocessing scheme that includes an n-dimensional bisection and that determines the foregoing parameters before deciding upon an appropriate GA for all problems of similar nature and type. Such a preprocessing is not only fast but also enables us to get the global optimal solution and its reasonably narrow error bounds with a high degree of confidence.

  6. Learning from 25 years of the extensible N-Dimensional Data Format

    NASA Astrophysics Data System (ADS)

    Jenness, T.; Berry, D. S.; Currie, M. J.; Draper, P. W.; Economou, F.; Gray, N.; McIlwrath, B.; Shortridge, K.; Taylor, M. B.; Wallace, P. T.; Warren-Smith, R. F.

    2015-09-01

    The extensible N-Dimensional Data Format (NDF) was designed and developed in the late 1980s to provide a data model suitable for use in a variety of astronomy data processing applications supported by the UK Starlink Project. Starlink applications were used extensively, primarily in the UK astronomical community, and form the basis of a number of advanced data reduction pipelines today. This paper provides an overview of the historical drivers for the development of NDF and the lessons learned from using a defined hierarchical data model for many years in data reduction software, data pipelines and in data acquisition systems.

  7. Intrinsic Patterns of Human Activity

    NASA Astrophysics Data System (ADS)

    Hu, Kun; Ivanov, Plamen Ch.; Chen, Zhi; Hilton, Michael; Stanley, H. Eugene; Shea, Steven

    2003-03-01

    Activity is one of the defining features of life. Control of human activity is complex, being influenced by many factors both extrinsic and intrinsic to the body. The most obvious extrinsic factors that affect activity are the daily schedule of planned events, such as work and recreation, as well as reactions to unforeseen or random events. These extrinsic factors may account for the apparently random fluctuations in human motion observed over short time scales. The most obvious intrinsic factors are the body clocks including the circadian pacemaker that influences our sleep/wake cycle and ultradian oscillators with shorter time scales [2, 3]. These intrinsic rhythms may account for the underlying regularity in average activity level over longer periods of up to 24 h. Here we ask if the known extrinsic and intrinsic factors fully account for all complex features observed in recordings of human activity. To this end, we measure activity over two weeks from forearm motion in subjects undergoing their regular daily routine. Utilizing concepts from statistical physics, we demonstrate that during wakefulness human activity possesses previously unrecognized complex dynamic patterns. These patterns of activity are characterized by robust fractal and nonlinear dynamics including a universal probability distribution and long-range power-law correlations that are stable over a wide range of time scales (from minutes to hours). Surprisingly, we find that these dynamic patterns are unaffected by changes in the average activity level that occur within individual subjects throughout the day and on different days of the week, and between subjects. Moreover, we find that these patterns persist when the same subjects undergo time-isolation laboratory experiments designed to account for the phase of the circadian pacemaker, and control the known extrinsic factors by restricting behaviors and manipulating scheduled events including the sleep/wake cycle. We attribute these newly

  8. Palatalization and Intrinsic Prosodic Vowel Features in Russian

    ERIC Educational Resources Information Center

    Ordin, Mikhail

    2011-01-01

    The presented study is aimed at investigating the interaction of palatalization and intrinsic prosodic features of the vowel in CVC (consonant+vowel+consonant) syllables in Russian. The universal nature of intrinsic prosodic vowel features was confirmed with the data from the Russian language. It was found that palatalization of the consonants…

  9. Predicting Intrinsic Motivation

    ERIC Educational Resources Information Center

    Martens, Rob; Kirschner, Paul A.

    2004-01-01

    Intrinsic motivation can be predicted from participants' perceptions of the social environment and the task environment (Ryan & Deci, 2000)in terms of control, relatedness and competence. To determine the degree of independence of these factors 251 students in higher vocational education (physiotherapy and hotel management) indicated the extent to…

  10. Intrinsic and Extrinsic Job Satisfaction Characteristics Among Pharmacy Students.

    ERIC Educational Resources Information Center

    Purohit, Anal A.; Lambert, Randall L.

    1983-01-01

    Of 20 extrinsic and intrinsic factors relating to job satisfaction, pharmacy students at the University of Illinois most frequently selected these: salaries, sense of accomplishment, use of training, learning opportunities, and relationships with coworkers. (MSE)

  11. Bifurcation Analysis in an n-Dimensional Diffusive Competitive Lotka-Volterra System with Time Delay

    NASA Astrophysics Data System (ADS)

    Chang, Xiaoyuan; Wei, Junjie

    2015-06-01

    In this paper, we investigate the stability and Hopf bifurcation of an n-dimensional competitive Lotka-Volterra diffusion system with time delay and homogeneous Dirichlet boundary condition. We first show that there exists a positive nonconstant steady state solution satisfying the given asymptotic expressions and establish the stability of the positive nonconstant steady state solution. Regarding the time delay as a bifurcation parameter, we explore the system that undergoes a Hopf bifurcation near the positive nonconstant steady state solution and derive a calculation method for determining the direction of the Hopf bifurcation. Finally, we cite the stability of a three-dimensional competitive Lotka-Volterra diffusion system with time delay to illustrate our conclusions.

  12. Parameterized center manifold for unfolding bifurcations with an eigenvalue +1 in n-dimensional maps

    NASA Astrophysics Data System (ADS)

    Wen, Guilin; Yin, Shan; Xu, Huidong; Zhang, Sijin; Lv, Zengyao

    2016-10-01

    For the fold bifurcation with an eigenvalue +1, there are three types of potential solutions from saddle-node bifurcation, transcritical bifurcation and pitchfork bifurcation. In the existing analysis methods for high maps, there is a problem that for the fold bifurcation, saddle-node bifurcation and transcritical bifurcation cannot be distinguished by the center manifold without bifurcation parameter. In this paper, a parameterized center manifold has been derived to unfold the solutions of the fold bifurcation with an eigenvalue +1, which is used to reduce a general n-dimensional map to one-dimensional map. On the basis of the reduced map, the conditions of the fold bifurcations including saddle-node bifurcation, transcritical bifurcation and pitchfork bifurcation are established for general maps, respectively. We show the applications of the proposed bifurcation conditions by three four-dimensional map examples to distinguish saddle-node bifurcation, transcritical bifurcation and pitchfork bifurcation.

  13. Fractional diffusion equation for an n -dimensional correlated Lévy walk

    NASA Astrophysics Data System (ADS)

    Taylor-King, Jake P.; Klages, Rainer; Fedotov, Sergei; Van Gorder, Robert A.

    2016-07-01

    Lévy walks define a fundamental concept in random walk theory that allows one to model diffusive spreading faster than Brownian motion. They have many applications across different disciplines. However, so far the derivation of a diffusion equation for an n -dimensional correlated Lévy walk remained elusive. Starting from a fractional Klein-Kramers equation here we use a moment method combined with a Cattaneo approximation to derive a fractional diffusion equation for superdiffusive short-range auto-correlated Lévy walks in the large time limit, and we solve it. Our derivation discloses different dynamical mechanisms leading to correlated Lévy walk diffusion in terms of quantities that can be measured experimentally.

  14. Lattice Boltzmann method for n-dimensional nonlinear hyperbolic conservation laws with the source term.

    PubMed

    Wang, Zhenghua; Shi, Baochang; Xiang, Xiuqiao; Chai, Zhenhua; Lu, Jianhua

    2011-03-01

    It is important for nonlinear hyperbolic conservation laws (NHCL) to own a simulation scheme with high order accuracy, simple computation, and non-oscillatory character. In this paper, a unified and novel lattice Boltzmann model is presented for solving n-dimensional NHCL with the source term. By introducing the high order source term of explicit lattice Boltzmann method (LBM) and the optimum dimensionless relaxation time varied with the specific issues, the effects of space and time resolutions on the accuracy and stability of the model are investigated for the different problems in one to three dimensions. Both the theoretical analysis and numerical simulation validate that the results by the proposed LBM have second-order accuracy in both space and time, which agree well with the analytical solutions.

  15. Fractional diffusion equation for an n-dimensional correlated Lévy walk.

    PubMed

    Taylor-King, Jake P; Klages, Rainer; Fedotov, Sergei; Van Gorder, Robert A

    2016-07-01

    Lévy walks define a fundamental concept in random walk theory that allows one to model diffusive spreading faster than Brownian motion. They have many applications across different disciplines. However, so far the derivation of a diffusion equation for an n-dimensional correlated Lévy walk remained elusive. Starting from a fractional Klein-Kramers equation here we use a moment method combined with a Cattaneo approximation to derive a fractional diffusion equation for superdiffusive short-range auto-correlated Lévy walks in the large time limit, and we solve it. Our derivation discloses different dynamical mechanisms leading to correlated Lévy walk diffusion in terms of quantities that can be measured experimentally. PMID:27575074

  16. Intrinsically Disordered Energy Landscapes

    NASA Astrophysics Data System (ADS)

    Chebaro, Yassmine; Ballard, Andrew J.; Chakraborty, Debayan; Wales, David J.

    2015-05-01

    Analysis of an intrinsically disordered protein (IDP) reveals an underlying multifunnel structure for the energy landscape. We suggest that such ‘intrinsically disordered’ landscapes, with a number of very different competing low-energy structures, are likely to characterise IDPs, and provide a useful way to address their properties. In particular, IDPs are present in many cellular protein interaction networks, and several questions arise regarding how they bind to partners. Are conformations resembling the bound structure selected for binding, or does further folding occur on binding the partner in a induced-fit fashion? We focus on the p53 upregulated modulator of apoptosis (PUMA) protein, which adopts an -helical conformation when bound to its partner, and is involved in the activation of apoptosis. Recent experimental evidence shows that folding is not necessary for binding, and supports an induced-fit mechanism. Using a variety of computational approaches we deduce the molecular mechanism behind the instability of the PUMA peptide as a helix in isolation. We find significant barriers between partially folded states and the helix. Our results show that the favoured conformations are molten-globule like, stabilised by charged and hydrophobic contacts, with structures resembling the bound state relatively unpopulated in equilibrium.

  17. Intrinsically disordered energy landscapes.

    PubMed

    Chebaro, Yassmine; Ballard, Andrew J; Chakraborty, Debayan; Wales, David J

    2015-01-01

    Analysis of an intrinsically disordered protein (IDP) reveals an underlying multifunnel structure for the energy landscape. We suggest that such 'intrinsically disordered' landscapes, with a number of very different competing low-energy structures, are likely to characterise IDPs, and provide a useful way to address their properties. In particular, IDPs are present in many cellular protein interaction networks, and several questions arise regarding how they bind to partners. Are conformations resembling the bound structure selected for binding, or does further folding occur on binding the partner in a induced-fit fashion? We focus on the p53 upregulated modulator of apoptosis (PUMA) protein, which adopts an α-helical conformation when bound to its partner, and is involved in the activation of apoptosis. Recent experimental evidence shows that folding is not necessary for binding, and supports an induced-fit mechanism. Using a variety of computational approaches we deduce the molecular mechanism behind the instability of the PUMA peptide as a helix in isolation. We find significant barriers between partially folded states and the helix. Our results show that the favoured conformations are molten-globule like, stabilised by charged and hydrophobic contacts, with structures resembling the bound state relatively unpopulated in equilibrium. PMID:25999294

  18. Homogeneous Lotka-Volterra Equation Possessing a Lie Symmetry: Extension to n-Dimensional Equation and Integrability

    NASA Astrophysics Data System (ADS)

    Imai, Kenji

    2014-02-01

    In this paper, a new n-dimensional homogeneous Lotka-Volterra (HLV) equation, which possesses a Lie symmetry, is derived by the extension from a three-dimensional HLV equation. Its integrability is shown from the viewpoint of Lie symmetries. Furthermore, we derive dynamical systems of higher order, which possess the Lie symmetry, using the algebraic structure of this HLV equation.

  19. Canonical formalism for a 2n-dimensional model with topological mass generation

    NASA Astrophysics Data System (ADS)

    Deguchi, Shinichi

    2008-12-01

    The four-dimensional model with topological mass generation that was found by Dvali, Jackiw, and Pi has recently been generalized to any even number of dimensions (2n dimensions) in a nontrivial manner in which a Stückelberg-type mass term is introduced [S. Deguchi and S. Hayakawa, Phys. Rev. D 77, 045003 (2008)PRVDAQ0556-282110.1103/PhysRevD.77.045003]. The present paper deals with a self-contained model, called here a modified hybrid model, proposed in this 2n-dimensional generalization and considers the canonical formalism for this model. For the sake of convenience, the canonical formalism itself is studied for a model equivalent to the modified hybrid model by following the recipe for treating constrained Hamiltonian systems. This formalism is applied to the canonical quantization of the equivalent model in order to clarify observable and unobservable particles in the model. The equivalent model (with a gauge-fixing term) is converted to the modified hybrid model (with a corresponding gauge-fixing term) in a Becchi-Rouet-Stora-Tyutin-invariant manner. Thereby it is shown that the Chern-Pontryagin density behaves as an observable massive particle (or field). The topological mass generation is thus verified at the quantum-theoretical level.

  20. Spherically symmetric solutions of a (4 + n)-dimensional Einstein Yang Mills model with cosmological constant

    NASA Astrophysics Data System (ADS)

    Brihaye, Yves; Hartmann, Betti

    2005-01-01

    We construct solutions of an Einstein Yang Mills system including a cosmological constant in 4 + n spacetime dimensions, where the n-dimensional manifold associated with the extra dimensions is taken to be Ricci flat. Assuming the matter and metric fields to be independent of the n extra coordinates, a spherical symmetric ansatz for the fields leads to a set of coupled ordinary differential equations. We find that for n > 1 only solutions with either one non-zero Higgs field or with all Higgs fields constant and zero gauge field function (corresponding to a Wu Yang-type ansatz) exist. We give the analytic solutions available in this model. These are 'embedded' Abelian solutions with a diverging size of the manifold associated with the extra n dimensions. Depending on the choice of parameters, these latter solutions either represent naked singularities or they possess a single horizon. We also present solutions of the effective four-dimensional Einstein Yang Mills Higgs-dilaton model, where the higher-dimensional cosmological constant induces a Liouville-type potential. The solutions are non-Abelian solutions with diverging Higgs fields, which exist only up to a maximal value of the cosmological constant.

  1. n-dimensional non uniform rational b-splines for metamodeling

    SciTech Connect

    Turner, Cameron J; Crawford, Richard H

    2008-01-01

    Non Uniform Rational B-splines (NURBs) have unique properties that make them attractive for engineering metamodeling applications. NURBs are known to accurately model many different continuous curve and surface topologies in 1- and 2-variate spaces. However, engineering metamodels of the design space often require hypervariate representations of multidimensional outputs. In essence, design space metamodels are hyperdimensional constructs with a dimensionality determined by their input and output variables. To use NURBs as the basis for a metamodel in a hyperdimensional space, traditional geometric fitting techniques must be adapted to hypervariate and hyperdimensional spaces composed of both continuous and discontinuous variable types. In this paper, they describe the necessary adaptations for the development of a NURBs-based metamodel called a Hyperdimensional Performance Model or HyPerModel. HyPerModels are capable of accurately and reliably modeling nonlinear hyperdimensional objects defined by both continuous and discontinuous variables of a wide variety of topologies, such as those that define typical engineering design spaces. They demonstrate this ability by successfully generating accurate HyPerModels of 10 trial functions laying the foundation for future work with N-dimensional NURBs in design space applications.

  2. N-dimensional animal energetic niches clarify behavioural options in a variable marine environment.

    PubMed

    Wilson, Rory P; McMahon, Clive R; Quintana, Flavio; Frere, Esteban; Scolaro, Alejandro; Hays, Graeme C; Bradshaw, Corey J A

    2011-02-15

    Animals respond to environmental variation by exhibiting a number of different behaviours and/or rates of activity, which result in corresponding variation in energy expenditure. Successful animals generally maximize efficiency or rate of energy gain through foraging. Quantification of all features that modulate energy expenditure can theoretically be modelled as an animal energetic niche or power envelope; with total power being represented by the vertical axis and n-dimensional horizontal axes representing extents of processes that affect energy expenditure. Such an energetic niche could be used to assess the energetic consequences of animals adopting particular behaviours under various environmental conditions. This value of this approach was tested by constructing a simple mechanistic energetics model based on data collected from recording devices deployed on 41 free-living Magellanic penguins (Spheniscus magellanicus), foraging from four different colonies in Argentina and consequently catching four different types of prey. Energy expenditure was calculated as a function of total distance swum underwater (horizontal axis 1) and maximum depth reached (horizontal axis 2). The resultant power envelope was invariant, irrespective of colony location, but penguins from the different colonies tended to use different areas of the envelope. The different colony solutions appeared to represent particular behavioural options for exploiting the available prey and demonstrate how penguins respond to environmental circumstance (prey distribution), the energetic consequences that this has for them, and how this affects the balance of energy acquisition through foraging and expenditure strategy. PMID:21270314

  3. Out-of-core Compression and Decompression of Large n-dimensional Scalar Fields

    SciTech Connect

    Ibarria, L; Lindstrom, P; Rossignac, J; Szymczak, A

    2003-02-03

    We present a simple method for compressing very large and regularly sampled scalar fields. Our method is particularly attractive when the entire data set does not fit in memory and when the sampling rate is high relative to the feature size of the scalar field in all dimensions. Although we report results for R{sup 3} and R{sup 4} data sets, the proposed approach may be applied to higher dimensions. The method is based on the new Lorenzo predictor, introduced here, which estimates the value of the scalar field at each sample from the values at processed neighbors. The predicted values are exact when the n-dimensional scalar field is an implicit polynomial of degree n-1. Surprisingly, when the residuals (differences between the actual and predicted values) are encoded using arithmetic coding, the proposed method often outperforms wavelet compression in an L{infinity} sense. The proposed approach may be used both for lossy and lossless compression and is well suited for out-of-core compression and decompression, because a trivial implementation, which sweeps through the data set reading it once, requires maintaining only a small buffer in core memory, whose size barely exceeds a single n-1 dimensional slice of the data.

  4. Out-of-Core Compression and Decompression of Large n-Dimensional Scalar Fields

    SciTech Connect

    Ibarria, L; Lindstrom, P; Rossignac, J; Szymczak, A

    2003-05-07

    We present a simple method for compressing very large and regularly sampled scalar fields. Our method is particularly attractive when the entire data set does not fit in memory and when the sampling rate is high relative to the feature size of the scalar field in all dimensions. Although we report results for R{sup 3} and R{sup 4} data sets, the proposed approach may be applied to higher dimensions. The method is based on the new Lorenzo predictor, introduced here, which estimates the value of the scalar field at each sample from the values at processed neighbors. The predicted values are exact when the n-dimensional scalar field is an implicit polynomial of degree n-1. Surprisingly, when the residuals (differences between the actual and predicted values) are encoded using arithmetic coding, the proposed method often outperforms wavelet compression in an L{infinity} sense. The proposed approach may be used both for lossy and lossless compression and is well suited for out-of-core compression and decompression, because a trivial implementation, which sweeps through the data set reading it once, requires maintaining only a small buffer in core memory, whose size barely exceeds a single n-1 dimensional slice of the data.

  5. Canonical formalism for a 2n-dimensional model with topological mass generation

    SciTech Connect

    Deguchi, Shinichi

    2008-12-15

    The four-dimensional model with topological mass generation that was found by Dvali, Jackiw, and Pi has recently been generalized to any even number of dimensions (2n dimensions) in a nontrivial manner in which a Stueckelberg-type mass term is introduced [S. Deguchi and S. Hayakawa, Phys. Rev. D 77, 045003 (2008)]. The present paper deals with a self-contained model, called here a modified hybrid model, proposed in this 2n-dimensional generalization and considers the canonical formalism for this model. For the sake of convenience, the canonical formalism itself is studied for a model equivalent to the modified hybrid model by following the recipe for treating constrained Hamiltonian systems. This formalism is applied to the canonical quantization of the equivalent model in order to clarify observable and unobservable particles in the model. The equivalent model (with a gauge-fixing term) is converted to the modified hybrid model (with a corresponding gauge-fixing term) in a Becchi-Rouet-Stora-Tyutin-invariant manner. Thereby it is shown that the Chern-Pontryagin density behaves as an observable massive particle (or field). The topological mass generation is thus verified at the quantum-theoretical level.

  6. Computing n-dimensional volumes of complexes: Application to constructive entropy bounds

    SciTech Connect

    Beiu, V.; Makaruk, H.E.

    1997-11-01

    The constructive bounds on the needed number-of-bits (entropy) for solving a dichotomy (i.e., classification of a given data-set into two distinct classes) can be represented by the quotient of two multidimensional solid volumes. Exact methods for the calculation of the volume of the solids lead to a tighter lower bound on the needed number-of-bits--than the ones previously known. Establishing such bounds is very important for engineering applications, as they can improve certain constructive neural learning algorithms, while also reducing the area of future VLSI implementations of neural networks. The paper will present an effective method for the exact calculation of the volume of any n-dimensional complex. The method uses a divide-and-conquer approach by: (i) partitioning (i.e., slicing) a complex into simplices; and (ii) computing the volumes of these simplices. The slicing of any complex into a sum of simplices always exists, but it is not unique. This non-uniqueness gives us the freedom to choose that specific partitioning which is convenient for a particular case. It will be shown that this optimal choice is related to the symmetries of the complex, and can significantly reduce the computations involved.

  7. Intrinsically variable stars

    NASA Technical Reports Server (NTRS)

    Bohm-Vitense, Erika; Querci, Monique

    1987-01-01

    The characteristics of intrinsically variable stars are examined, reviewing the results of observations obtained with the IUE satellite since its launch in 1978. Selected data on both medium-spectral-class pulsating stars (Delta Cep stars, W Vir stars, and related groups) and late-type variables (M, S, and C giants and supergiants) are presented in spectra, graphs, and tables and described in detail. Topics addressed include the calibration of the the period-luminosity relation, Cepheid distance determination, checking stellar evolution theory by the giant companions of Cepheids, Cepheid masses, the importance of the hydrogen convection zone in Cepheids, temperature and abundance estimates for Population II pulsating stars, mass loss in Population II Cepheids, SWP and LWP images of cold giants and supergiants, temporal variations in the UV lines of cold stars, C-rich cold stars, and cold stars with highly ionized emission lines.

  8. Intrinsic anion oxidation potentials.

    PubMed

    Johansson, Patrik

    2006-11-01

    Anions of lithium battery salts have been investigated by electronic structure calculations with the objective to find a computational measure to correlate with the observed (in)stability of nonaqueous lithium battery electrolytes vs oxidation often encountered in practice. Accurate prediction of intrinsic anion oxidation potentials is here made possible by computing the vertical free energy difference between anion and neutral radical (Delta Gv) and further strengthened by an empirical correction using only the anion volume as a parameter. The 6-311+G(2df,p) basis set, the VSXC functional, and the C-PCM SCRF algorithm were used. The Delta Gv calculations can be performed using any standard computational chemistry software. PMID:17078600

  9. Intrinsic Feature Motion Tracking

    SciTech Connect

    Goddard, Jr., James S.

    2013-03-19

    Subject motion during 3D medical scanning can cause blurring and artifacts in the 3D images resulting in either rescans or poor diagnosis. Anesthesia or physical restraints may be used to eliminate motion but are undesirable and can affect results. This software measures the six degree of freedom 3D motion of the subject during the scan under a rigidity assumption using only the intrinsic features present on the subject area being monitored. This movement over time can then be used to correct the scan data removing the blur and artifacts. The software acquires images from external cameras or images stored on disk for processing. The images are from two or three calibrated cameras in a stereo arrangement. Algorithms extract and track the features over time and calculate position and orientation changes relative to an initial position. Output is the 3D position and orientation change measured at each image.

  10. Intrinsic Feature Motion Tracking

    2013-03-19

    Subject motion during 3D medical scanning can cause blurring and artifacts in the 3D images resulting in either rescans or poor diagnosis. Anesthesia or physical restraints may be used to eliminate motion but are undesirable and can affect results. This software measures the six degree of freedom 3D motion of the subject during the scan under a rigidity assumption using only the intrinsic features present on the subject area being monitored. This movement over timemore » can then be used to correct the scan data removing the blur and artifacts. The software acquires images from external cameras or images stored on disk for processing. The images are from two or three calibrated cameras in a stereo arrangement. Algorithms extract and track the features over time and calculate position and orientation changes relative to an initial position. Output is the 3D position and orientation change measured at each image.« less

  11. Intrinsic Chevrolets at the SSC

    SciTech Connect

    Brodsky, S.J.; Collins, J.C.; Ellis, S.D.; Gunion, J.F.; Mueller, A.H.

    1984-01-01

    The possibility of the production at high energy of heavy quarks, supersymmetric particles and other large mass colored systems via the intrinsic twist-six components in the proton wave function is discussed. While the existing data do not rule out the possible relevance of intrinsic charm production at present energies, the extrapolation of such intrinsic contributions to very high masses and energies suggests that they will not play an important role at the SSC.

  12. Qutrit teleportation under intrinsic decoherence

    NASA Astrophysics Data System (ADS)

    Jafarpour, Mojtaba; Naderi, Negar

    2016-08-01

    We study qutrit teleportation and its fidelity in the presence and absence of intrinsic decoherence through a qutrit channel. The channel consists of a Heisenberg chain with xyz interaction model and the intrinsic decoherence is implemented through the Milburn model. It is shown that while the fidelity diminishes due to intrinsic decoherence, it may be enhanced if the channel is initially in an entangled state. It is also observed that, for stronger intrinsic decoherence, the initial entanglement of the channel is more effective in enhancing of fidelity.

  13. Intrinsic time in Wheeler-DeWitt conformal superspace

    NASA Astrophysics Data System (ADS)

    Pavlov, A. E.; Pervushin, V. N.

    In Geometrodynamics, the York's extrinsic time, constructed of the tensor of extrinsic curvature and the Misner's intrinsic time, built of the spatial metric tensor, coexist. In our paper, we prove the preference of selecting the internal time. To extract the intrinsic time, we generalize the Dirac's mapping of transition to conformal variables. In Friedmann cosmology, the many-fingered intrinsic time obtains a sense of a global time of the Universe. An accounting of metric scalar linear perturbations leads to adding some corrections not dominated to the effective energy density in the Hubble law. The metric vector and tensor perturbations do not influence the internal time in linear approximation.

  14. ND2 AV: N-dimensional data analysis and visualization analysis for the National Ignition Campaign

    DOE PAGESBeta

    Bremer, Peer -Timo; Maljovec, Dan; Saha, Avishek; Wang, Bei; Gaffney, Jim; Spears, Brian K.; Pascucci, Valerio

    2015-07-01

    Here, one of the biggest challenges in high-energy physics is to analyze a complex mix of experimental and simulation data to gain new insights into the underlying physics. Currently, this analysis relies primarily on the intuition of trained experts often using nothing more sophisticated than default scatter plots. Many advanced analysis techniques are not easily accessible to scientists and not flexible enough to explore the potentially interesting hypotheses in an intuitive manner. Furthermore, results from individual techniques are often difficult to integrate, leading to a confusing patchwork of analysis snippets too cumbersome for data exploration. This paper presents a case study on how a combination of techniques from statistics, machine learning, topology, and visualization can have a significant impact in the field of inertial confinement fusion. We present themore » $$\\mathrm{ND}^2\\mathrm{AV}$$: N-dimensional data analysis and visualization framework, a user-friendly tool aimed at exploiting the intuition and current workflow of the target users. The system integrates traditional analysis approaches such as dimension reduction and clustering with state-of-the-art techniques such as neighborhood graphs and topological analysis, and custom capabilities such as defining combined metrics on the fly. All components are linked into an interactive environment that enables an intuitive exploration of a wide variety of hypotheses while relating the results to concepts familiar to the users, such as scatter plots. $$\\mathrm{ND}^2\\mathrm{AV}$$ uses a modular design providing easy extensibility and customization for different applications. $$\\mathrm{ND}^2\\mathrm{AV}$$ is being actively used in the National Ignition Campaign and has already led to a number of unexpected discoveries.« less

  15. Intrinsically irreversible heat engine

    DOEpatents

    Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1984-01-01

    A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. the second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

  16. Intrinsically irreversible heat engine

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1984-12-25

    A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. The second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat. 11 figs.

  17. Intrinsically irreversible heat engine

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1984-01-01

    A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. The second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

  18. Intrinsic Angular Momentum of Light.

    ERIC Educational Resources Information Center

    Santarelli, Vincent

    1979-01-01

    Derives a familiar torque-angular momentum theorem for the electromagnetic field, and includes the intrinsic torques exerted by the fields on the polarized medium. This inclusion leads to the expressions for the intrinsic angular momentum carried by the radiation traveling through a charge-free medium. (Author/MA)

  19. Intrinsic Negative Mass from Nonlinearity

    NASA Astrophysics Data System (ADS)

    Di Mei, F.; Caramazza, P.; Pierangeli, D.; Di Domenico, G.; Ilan, H.; Agranat, A. J.; Di Porto, P.; DelRe, E.

    2016-04-01

    We propose and provide experimental evidence of a mechanism able to support negative intrinsic effective mass. The idea is to use a shape-sensitive nonlinearity to change the sign of the mass in the leading linear propagation equation. Intrinsic negative-mass dynamics is reported for light beams in a ferroelectric crystal substrate, where the diffusive photorefractive nonlinearity leads to a negative-mass Schrödinger equation. The signature of inverted dynamics is the observation of beams repelled from strongly guiding integrated waveguides irrespective of wavelength and intensity and suggests shape-sensitive nonlinearity as a basic mechanism leading to intrinsic negative mass.

  20. ON THE GEOMETRY OF MEASURABLE SETS IN N-DIMENSIONAL SPACE ON WHICH GENERALIZED LOCALIZATION HOLDS FOR MULTIPLE FOURIER SERIES OF FUNCTIONS IN L_p, p>1

    NASA Astrophysics Data System (ADS)

    Bloshanskiĭ, I. L.

    1984-02-01

    The precise geometry is found of measurable sets in N-dimensional Euclidean space on which generalized localization almost everywhere holds for multiple Fourier series which are rectangularly summable.Bibliography: 14 titles.

  1. Quantifying intrinsic and extrinsic factors affecting soil erodibility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erodibility has traditionally been conceived as a soil dependent parameter that can be quantified from intrinsic soil properties that usually stay constant. Development of erosion prediction equations, from the empirical-based Universal Soil Loss Equation (USLE) to a more processed-based Water ...

  2. Intrinsic Motivation as a Mediator on Imaginative Capability Development

    ERIC Educational Resources Information Center

    Liang, Chaoyun; Hsu, Yuling; Chang, Chi-Cheng

    2013-01-01

    The present study explored which environmental and psychological variables influenced the imagination of video/film major university students, and the effects these variables had on their imaginative capability development. The hypothesis of the study--that "intrinsic motivation" played a mediating role in imaginative capability development--was…

  3. Recognizing Volunteer Practitioner-Educators through Intrinsic and Extrinsic Incentives.

    ERIC Educational Resources Information Center

    Beck, Diane E.; And Others

    1995-01-01

    A project in five pharmacy schools assessed the effectiveness of intrinsic and extrinsic incentives and rewards to enhance volunteer practitioner-educators' perceptions of recognition of their teaching contributions. Benefits used included awards and appointments, access to university facilities, discounts, tangible items, and mechanisms to…

  4. Measurable genuine tripartite entanglement of (2 ⊗2 ⊗n )-dimensional quantum states via only two simultaneous copies

    NASA Astrophysics Data System (ADS)

    Yu, Chang-shui; Guo, Bao-qing; Yang, Si-ren

    2016-04-01

    Usually, the three-tangle of a tripartite pure state of qubits can be directly measured with the simultaneous preparation of a not-less-than fourfold copy of the state. We show that the exact genuine tripartite entanglement for (2 ⊗2 ⊗n )-dimensional pure quantum states can be measured in a similar manner, provided that only two simultaneous copies of the state are available. Lower bounds are also proposed for more convenient experimental operations. As an example, a comprehensive demonstration of the scheme is provided for the three-tangle of a three-qubit state.

  5. Nondestructive testing of 3D disperse systems with micro- and nano-particles: N-dimensional space of optical parameters

    NASA Astrophysics Data System (ADS)

    Bezrukova, Alexandra G.

    2006-04-01

    The simultaneous analysis of 3D disperse systems (DS) with micro- and nano- particles by refractometry, absorbency, fluorescence and by different types of light scattering, can help to elaborate the sensing elements for specffic impurity control. Our research has investigated by complex of optical methods different 3D DS such as: proteins, nucleoproteids, lipoproteids, liposomes, viruses, virosomes, lipid emulsions, blood substitutes, latexes, liquid crystals, biological cells with various form and size (including bacterial cells), metallic powders, clays, kimberlites, zeolites, oils, crude oils, samples of natural and water-supply waters, etc. This experience suggests that each 3D DS can be charactensed by N-dimensional vector in N-dimensional space of optical parameters. Due to the fusion of various optical data it is possible to solve the inverse physical problem on the presence of impurity in mixtures of 3D DS by information statistical theory methods. It is important that in this case polymodality of particle size distribution is not an obstacle.

  6. Perfectionism and life aspirations in intrinsically and extrinsically religious individuals.

    PubMed

    Steffen, Patrick R

    2014-08-01

    Religiosity is related to positive health and life satisfaction but the pathways through which this occurs have not been clearly delineated. The purpose of this study was to examine potential mediators of the relationships between intrinsic and extrinsic religiosity and negative affect and life satisfaction. Perfectionism and life aspirations are two possible pathways through which religious orientation is related to outcome. It was hypothesized that adaptive perfectionism and intrinsic life aspirations would act as mediators between intrinsic religiosity and negative affect and life satisfaction, and that maladaptive perfectionism and extrinsic life aspirations would act as mediators between the extrinsic religiosity and negative affect and life satisfaction. Two consecutive samples of religious college students (N = 540 and N = 485) completed measures of the Age Universal Religious Orientation Index, the Frost Multi-Dimensional Perfectionism Scale, the Aspiration Index, the Beck Depression Inventory-II, the Spielberger State-Trait Anxiety Inventory, and the Satisfaction with Life Scale. Intrinsic religiosity had a direct negative relationship with negative affect and positive relationship with life satisfaction. Contrary to the hypotheses, intrinsic religiosity had its strongest indirect effect via maladaptive perfectionism such that increased intrinsic religiosity was related to decreased maladaptive perfectionism which in turn lead to better negative affect and life satisfaction. Extrinsic religiosity was related to increased maladaptive perfectionism and thereby indirectly contributed to worse negative affect and life satisfaction. Interestingly, when the effects of maladaptive perfectionism were controlled, the direct effects of extrinsic religiosity were related to reduced negative affect and increased life satisfaction. Overall, the strongest mediator in this study of both intrinsic and extrinsic religiosity was maladaptive perfectionism, with intrinsic

  7. Stimuli-sensitive intrinsically disordered protein brushes

    NASA Astrophysics Data System (ADS)

    Srinivasan, Nithya; Bhagawati, Maniraj; Ananthanarayanan, Badriprasad; Kumar, Sanjay

    2014-10-01

    Grafting polymers onto surfaces at high density to yield polymer brush coatings is a widely employed strategy to reduce biofouling and interfacial friction. These brushes almost universally feature synthetic polymers, which are often heterogeneous and do not readily allow incorporation of chemical functionalities at precise sites along the constituent chains. To complement these synthetic systems, we introduce a biomimetic, recombinant intrinsically disordered protein that can assemble into an environment-sensitive brush. This macromolecule adopts an extended conformation and can be grafted to solid supports to form oriented protein brushes that swell and collapse dramatically with changes in solution pH and ionic strength. We illustrate the value of sequence specificity by using proteases with mutually orthogonal recognition sites to modulate brush height in situ to predictable values. This study demonstrates that stimuli-responsive brushes can be fabricated from proteins and introduces them as a new class of smart biomaterial building blocks.

  8. What is intrinsic atopic dermatitis?

    PubMed

    Roguedas-Contios, Anne-Marie; Misery, Laurent

    2011-12-01

    Many authors favor a distinction between the extrinsic and intrinsic forms of atopic dermatitis. In this review, the controversy is discussed and several definitions are presented. After reviewing many papers on this topic, it is our opinion that it is useful to separate the intrinsic and extrinsic forms of atopic dermatitis or atopic eczema and atopiform dermatitis because the pathophysiology appears to be different between them. However, these terms require concrete definition and clarification of the distinction between these two concepts. This debate is a new step in the history of atopic dermatitis. It is possible that a single patient could suffer from one form and then from another but genetic differences suggest that two types could really exist.

  9. Quasar redshifts: the intrinsic component

    NASA Astrophysics Data System (ADS)

    Hansen, Peter M.

    2016-09-01

    The large observed redshift of quasars has suggested large cosmological distances and a corresponding enormous energy output to explain the brightness or luminosity as seen at earth. Alternative or complementary sources of redshift have not been identified by the astronomical community. This study examines one possible source of additional redshift: an intrinsic component based on the plasma characteristics of high temperature and high electron density which are believed to be present.

  10. Decoherence: Intrinsic, Extrinsic, and Environmental

    NASA Astrophysics Data System (ADS)

    Stamp, Philip

    2012-02-01

    Environmental decoherence times have been difficult to predict in solid-state systems. In spin systems, environmental decoherence is predicted to arise from nuclear spins, spin-phonon interactions, and long-range dipolar interactions [1]. Recent experiments have confirmed these predictions quantitatively in crystals of Fe8 molecules [2]. Coherent spin dynamics was observed over macroscopic volumes, with a decoherence Q-factor Qφ= 1.5 x10^6 (the upper predicted limit in this system being Qφ= 6 x10^7). Decoherence from dipolar interactions is particularly complex, and depends on the shape and the quantum state of the system. No extrinsic ``noise'' decoherence was observed. The generalization to quantum dot and superconducting qubit systems is also discussed. We then discuss searches for ``intrinsic'' decoherence [3,4], coming from non-linear corrections to quantum mechanics. Particular attention is paid to condensed matter tests of such intrinsic decoherence, in hybrid spin/optomechanical systems, and to ways of distinguishing intrinsic decoherence from environmental and extrinsic decoherence sources. [4pt] [1] Morello, A. Stamp, P. C. E. & Tupitsyn, Phys. Rev. Lett. 97, 207206 (2006).[0pt] [2] S. Takahashi et al., Nature 476, 76 (2011).[0pt] [3] Stamp, P. C. E., Stud. Hist. Phil. Mod. Phys. 37, 467 (2006). [0pt] [4] Stamp, P.C.E., Phil. Trans. Roy. Soc. A (to be published)

  11. Troponins, intrinsic disorder, and cardiomyopathy.

    PubMed

    Na, Insung; Kong, Min J; Straight, Shelby; Pinto, Jose R; Uversky, Vladimir N

    2016-08-01

    Cardiac troponin is a dynamic complex of troponin C, troponin I, and troponin T (TnC, TnI, and TnT, respectively) found in the myocyte thin filament where it plays an essential role in cardiac muscle contraction. Mutations in troponin subunits are found in inherited cardiomyopathies, such as hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). The highly dynamic nature of human cardiac troponin and presence of numerous flexible linkers in its subunits suggest that understanding of structural and functional properties of this important complex can benefit from the consideration of the protein intrinsic disorder phenomenon. We show here that mutations causing decrease in the disorder score in TnI and TnT are significantly more abundant in HCM and DCM than mutations leading to the increase in the disorder score. Identification and annotation of intrinsically disordered regions in each of the troponin subunits conducted in this study can help in better understanding of the roles of intrinsic disorder in regulation of interactomes and posttranslational modifications of these proteins. These observations suggest that disease-causing mutations leading to a decrease in the local flexibility of troponins can trigger a whole plethora of functional changes in the heart. PMID:27074551

  12. Nuclear Filtering of Intrinsic Charm

    SciTech Connect

    Kopeliovich, B. Z.; Potashnikova, I. K.; Schmidt, Ivan

    2010-11-12

    Nuclei are transparent for a heavy intrinsic charm (IC) component of the beam hadrons, what leads to an enhanced nuclear dependence of open charm production at large Feynman x{sub F}. Indeed, such an effect is supported by data from the SELEX experiment published recently [1]. Our calculations reproduce well the data, providing strong support for the presence of IC in hadrons in amount less than 1%. Moreover, we performed an analysis of nuclear effects in J/{Psi} production and found at large x{sub F} a similar, albeit weaker effect, which does not contradict data.

  13. N-dimensional measurement-device-independent quantum key distribution with N + 1 un-characterized sources: zero quantum-bit-error-rate case.

    PubMed

    Hwang, Won-Young; Su, Hong-Yi; Bae, Joonwoo

    2016-07-25

    We study N-dimensional measurement-device-independent quantum-key-distribution protocol where one checking state is used. Only assuming that the checking state is a superposition of other N sources, we show that the protocol is secure in zero quantum-bit-error-rate case, suggesting possibility of the protocol. The method may be applied in other quantum information processing.

  14. N-dimensional measurement-device-independent quantum key distribution with N + 1 un-characterized sources: zero quantum-bit-error-rate case

    NASA Astrophysics Data System (ADS)

    Hwang, Won-Young; Su, Hong-Yi; Bae, Joonwoo

    2016-07-01

    We study N-dimensional measurement-device-independent quantum-key-distribution protocol where one checking state is used. Only assuming that the checking state is a superposition of other N sources, we show that the protocol is secure in zero quantum-bit-error-rate case, suggesting possibility of the protocol. The method may be applied in other quantum information processing.

  15. Is The Intrinsic Spin Hall Effect Measurable?

    NASA Astrophysics Data System (ADS)

    Yang, Zhaoyang

    2005-03-01

    Despite of the large intrinsic spin Hall conductivity in a spin- orbit coupled material predicted theoretically, we show that the intrinsic spin Hall effect in any diffusive sample is not measurable via conventional transport methods, thus the research on the intrinsic spin Hall effect is limited at the pure theoretical content. After generally defining the intrinsic and extrinsic transport coefficients, we show that the intrinsic magnetization Hall current, which is the sum of the intrinsic spin and intrinsic orbit-angular-momentum Hall currents, is identically zero. More importantly, we demonstrate that the equation of motion for the spin density does not depend on the intrinsic spin Hall current, therefore the transverse spin accumulation is solely determined by the extrinsic spin Hall current. The zero intrinsic magnetization Hall current and the independence of the spin accumulation on the intrinsic spin Hall effect lead us to conclude that the intrinsic spin Hall effect can not be assessed by conventional spin transport experiments based on the measurement of the magnetization current and the spin accumulation at the edge of the sample.

  16. Intrinsic ferroelectric switching from first principles.

    PubMed

    Liu, Shi; Grinberg, Ilya; Rappe, Andrew M

    2016-06-15

    The existence of domain walls, which separate regions of different polarization, can influence the dielectric, piezoelectric, pyroelectric and electronic properties of ferroelectric materials. In particular, domain-wall motion is crucial for polarization switching, which is characterized by the hysteresis loop that is a signature feature of ferroelectric materials. Experimentally, the observed dynamics of polarization switching and domain-wall motion are usually explained as the behaviour of an elastic interface pinned by a random potential that is generated by defects, which appear to be strongly sample-dependent and affected by various elastic, microstructural and other extrinsic effects. Theoretically, connecting the zero-kelvin, first-principles-based, microscopic quantities of a sample with finite-temperature, macroscopic properties such as the coercive field is critical for material design and device performance; and the lack of such a connection has prevented the use of techniques based on ab initio calculations for high-throughput computational materials discovery. Here we use molecular dynamics simulations of 90° domain walls (separating domains with orthogonal polarization directions) in the ferroelectric material PbTiO3 to provide microscopic insights that enable the construction of a simple, universal, nucleation-and-growth-based analytical model that quantifies the dynamics of many types of domain walls in various ferroelectrics. We then predict the temperature and frequency dependence of hysteresis loops and coercive fields at finite temperatures from first principles. We find that, even in the absence of defects, the intrinsic temperature and field dependence of the domain-wall velocity can be described with a nonlinear creep-like region and a depinning-like region. Our model enables quantitative estimation of coercive fields, which agree well with experimental results for ceramics and thin films. This agreement between model and experiment suggests

  17. Intrinsic ferroelectric switching from first principles

    NASA Astrophysics Data System (ADS)

    Liu, Shi; Grinberg, Ilya; Rappe, Andrew M.

    2016-06-01

    The existence of domain walls, which separate regions of different polarization, can influence the dielectric, piezoelectric, pyroelectric and electronic properties of ferroelectric materials. In particular, domain-wall motion is crucial for polarization switching, which is characterized by the hysteresis loop that is a signature feature of ferroelectric materials. Experimentally, the observed dynamics of polarization switching and domain-wall motion are usually explained as the behaviour of an elastic interface pinned by a random potential that is generated by defects, which appear to be strongly sample-dependent and affected by various elastic, microstructural and other extrinsic effects. Theoretically, connecting the zero-kelvin, first-principles-based, microscopic quantities of a sample with finite-temperature, macroscopic properties such as the coercive field is critical for material design and device performance; and the lack of such a connection has prevented the use of techniques based on ab initio calculations for high-throughput computational materials discovery. Here we use molecular dynamics simulations of 90° domain walls (separating domains with orthogonal polarization directions) in the ferroelectric material PbTiO3 to provide microscopic insights that enable the construction of a simple, universal, nucleation-and-growth-based analytical model that quantifies the dynamics of many types of domain walls in various ferroelectrics. We then predict the temperature and frequency dependence of hysteresis loops and coercive fields at finite temperatures from first principles. We find that, even in the absence of defects, the intrinsic temperature and field dependence of the domain-wall velocity can be described with a nonlinear creep-like region and a depinning-like region. Our model enables quantitative estimation of coercive fields, which agree well with experimental results for ceramics and thin films. This agreement between model and experiment suggests

  18. Intrinsic ferroelectric switching from first principles.

    PubMed

    Liu, Shi; Grinberg, Ilya; Rappe, Andrew M

    2016-06-16

    The existence of domain walls, which separate regions of different polarization, can influence the dielectric, piezoelectric, pyroelectric and electronic properties of ferroelectric materials. In particular, domain-wall motion is crucial for polarization switching, which is characterized by the hysteresis loop that is a signature feature of ferroelectric materials. Experimentally, the observed dynamics of polarization switching and domain-wall motion are usually explained as the behaviour of an elastic interface pinned by a random potential that is generated by defects, which appear to be strongly sample-dependent and affected by various elastic, microstructural and other extrinsic effects. Theoretically, connecting the zero-kelvin, first-principles-based, microscopic quantities of a sample with finite-temperature, macroscopic properties such as the coercive field is critical for material design and device performance; and the lack of such a connection has prevented the use of techniques based on ab initio calculations for high-throughput computational materials discovery. Here we use molecular dynamics simulations of 90° domain walls (separating domains with orthogonal polarization directions) in the ferroelectric material PbTiO3 to provide microscopic insights that enable the construction of a simple, universal, nucleation-and-growth-based analytical model that quantifies the dynamics of many types of domain walls in various ferroelectrics. We then predict the temperature and frequency dependence of hysteresis loops and coercive fields at finite temperatures from first principles. We find that, even in the absence of defects, the intrinsic temperature and field dependence of the domain-wall velocity can be described with a nonlinear creep-like region and a depinning-like region. Our model enables quantitative estimation of coercive fields, which agree well with experimental results for ceramics and thin films. This agreement between model and experiment suggests

  19. Mortality Anxiety as a Function of Intrinsic Religiosity and Perceived Purpose in Life

    ERIC Educational Resources Information Center

    Hui, Victoria Ka-Ying; Fung, Helene H.

    2009-01-01

    Fear of dying and death may be universal, but individuals differ in their emotional reactions to dying and death. The present study included a sample of 133 Chinese university students who were Christians. The authors tested a mediation model which posited that intrinsic religiosity, but not extrinsic religiosity, lowered anxiety toward the dying…

  20. Intrinsic rotation with gyrokinetic models

    SciTech Connect

    Parra, Felix I.; Barnes, Michael; Catto, Peter J.; Calvo, Ivan

    2012-05-15

    The generation of intrinsic rotation by turbulence and neoclassical effects in tokamaks is considered. To obtain the complex dependences observed in experiments, it is necessary to have a model of the radial flux of momentum that redistributes the momentum within the tokamak in the absence of a preexisting velocity. When the lowest order gyrokinetic formulation is used, a symmetry of the model precludes this possibility, making small effects in the gyroradius over scale length expansion necessary. These effects that are usually small become important for momentum transport because the symmetry of the lowest order gyrokinetic formulation leads to the cancellation of the lowest order momentum flux. The accuracy to which the gyrokinetic equation needs to be obtained to retain all the physically relevant effects is discussed.

  1. Stress-energy tensor correlators in N-dimensional hot flat spaces via the generalized zeta-function method

    NASA Astrophysics Data System (ADS)

    Cho, H. T.; Hu, B. L.

    2012-09-01

    We calculate the expectation values of the stress-energy bitensor defined at two different spacetime points x, x‧ of a massless, minimally coupled scalar field with respect to a quantum state at finite temperature T in a flat N-dimensional spacetime by means of the generalized zeta-function method. These correlators, also known as the noise kernels, give the fluctuations of energy and momentum density of a quantum field which are essential for the investigation of the physical effects of negative energy density in certain spacetimes or quantum states. They also act as the sources of the Einstein-Langevin equations in stochastic gravity which one can solve for the dynamics of metric fluctuations as in spacetime foams. In terms of constitutions these correlators are one rung above (in the sense of the correlation—BBGKY or Schwinger-Dyson—hierarchies) the mean (vacuum and thermal expectation) values of the stress-energy tensor which drive the semiclassical Einstein equation in semiclassical gravity. The low- and the high-temperature expansions of these correlators are also given here: at low temperatures, the leading order temperature dependence goes like TN while at high temperatures they have a T2 dependence with the subleading terms exponentially suppressed by e-T. We also discuss the singular behavior of the correlators in the x‧ → x coincident limit as was done before for massless conformal quantum fields. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical in honour of Stuart Dowker’s 75th birthday devoted to ‘Applications of zeta functions and other spectral functions in mathematics and physics’.

  2. ND2 AV: N-dimensional data analysis and visualization analysis for the National Ignition Campaign

    SciTech Connect

    Bremer, Peer -Timo; Maljovec, Dan; Saha, Avishek; Wang, Bei; Gaffney, Jim; Spears, Brian K.; Pascucci, Valerio

    2015-07-01

    Here, one of the biggest challenges in high-energy physics is to analyze a complex mix of experimental and simulation data to gain new insights into the underlying physics. Currently, this analysis relies primarily on the intuition of trained experts often using nothing more sophisticated than default scatter plots. Many advanced analysis techniques are not easily accessible to scientists and not flexible enough to explore the potentially interesting hypotheses in an intuitive manner. Furthermore, results from individual techniques are often difficult to integrate, leading to a confusing patchwork of analysis snippets too cumbersome for data exploration. This paper presents a case study on how a combination of techniques from statistics, machine learning, topology, and visualization can have a significant impact in the field of inertial confinement fusion. We present the $\\mathrm{ND}^2\\mathrm{AV}$: N-dimensional data analysis and visualization framework, a user-friendly tool aimed at exploiting the intuition and current workflow of the target users. The system integrates traditional analysis approaches such as dimension reduction and clustering with state-of-the-art techniques such as neighborhood graphs and topological analysis, and custom capabilities such as defining combined metrics on the fly. All components are linked into an interactive environment that enables an intuitive exploration of a wide variety of hypotheses while relating the results to concepts familiar to the users, such as scatter plots. $\\mathrm{ND}^2\\mathrm{AV}$ uses a modular design providing easy extensibility and customization for different applications. $\\mathrm{ND}^2\\mathrm{AV}$ is being actively used in the National Ignition Campaign and has already led to a number of unexpected discoveries.

  3. Universal nanopatternable interfacial bonding.

    PubMed

    Ding, Yuzhe; Garland, Shaun; Howland, Michael; Revzin, Alexander; Pan, Tingrui

    2011-12-01

    A nanopatternable polydimethylsiloxane (PDMS) oligomer layer is demonstrated as an interfacial adhesive for its intrinsic transferability and universal adhesiveness. Utilizing the well-established surface modification and bonding techniques of PDMS surfaces, irreversible bonding is formed (up to 400 kPa) between a wide range of substrate pairs, representing ones within and across different materials categories, including metals, ceramics, thermoset, and thermoplastic polymers.

  4. Intrinsic motivation in a competitive setting.

    PubMed

    Weinberg, R S

    1979-01-01

    The purpose of the present investigation was to determine the effects of success-failure and monetary reward on intrinsic motivation of males and females competing on a motor task. Results indicated a significant main effect for feedback with subjects exhibiting more intrinsic motivation after success than after failure. The Sex x Feedback interaction showed that males displayed more intrinsic motivation than females after success whereas females exhibited more intrinsic motivation than males after failure. Results are discussed in terms of Deci's cognitive evaluation theory and sex-role appropriate behaviors for males and females. Implications for competitive physical activity are drawn.

  5. Issues in Purchasing and Maintaining Intrinsic Standards

    SciTech Connect

    PETTIT,RICHARD B.; JAEGER,KLAUS; EHRLICH,CHARLES D.

    2000-09-12

    Intrinsic standards are widely used in the metrology community because they realize the best level uncertainty for many metrology parameters. For some intrinsic standards, recommended practices have been developed to assist metrologists in the selection of equipment and the development of appropriate procedures in order to realize the intrinsic standard. As with the addition of any new standard, the metrology laboratory should consider the pros and cons relative to their needs before purchasing the standard so that the laboratory obtains the maximum benefit from setting up and maintaining these standards. While the specific issues that need to be addressed depend upon the specific intrinsic standard and the level of realization, general issues that should be considered include ensuring that the intrinsic standard is compatible with the laboratory environment, that the standard is compatible with the current and future workload, and whether additional support standards will be required in order to properly maintain the intrinsic standard. When intrinsic standards are used to realize the best level of uncertainty for a specific metrology parameter, they usually require critical and important maintenance activities. These activities can including training of staff in the system operation, as well as safety procedures; performing periodic characterization measurements to ensure proper system operation; carrying out periodic intercomparisons with similar intrinsic standards so that proper operation is demonstrated; and maintaining control or trend charts of system performance. This paper has summarized many of these important issues and therefore should be beneficial to any laboratory that is considering the purchase of an intrinsic standard.

  6. A new approach to: (a) grid generation for numerical optimization, and (b) interconnect networks for beowulf clusters, leveraging n-dimensional sphere-packings

    NASA Astrophysics Data System (ADS)

    Bewley, Thomas; Cessna, Joseph; Belitz, Paul

    2008-11-01

    The abstract field of n-dimensional sphere packing theory is well developed (for a comprehensive review, see Sphere Packings, Lattices and Groups by Conway and Sloane). This theory forms the theoretical underpinning of the error-correcting codes used in both deep space communications and in computer memory. The present work extends this elegant theory to two important and immensely practical problems in computational fluid dynamics: (a) the generation of efficient grids for the coordination of grid-based derivative-free optimization algorithms in n dimensions, and (b) the effective n-dimensional interconnection of massively-parallel clusters of computational nodes. As we will illustrate and quantify, the first problem benefits tremendously from dense sphere packings with large kissing numbers >> 2n, whereas the latter problem benefits tremendously from rare sphere packings with kissing number = n+1.

  7. Intrinsic Localized Modes in Proteins

    PubMed Central

    Nicolaï, Adrien; Delarue, Patrice; Senet, Patrick

    2015-01-01

    Protein dynamics is essential for proteins to function. Here we predicted the existence of rare, large nonlinear excitations, termed intrinsic localized modes (ILMs), of the main chain of proteins based on all-atom molecular dynamics simulations of two fast-folder proteins and of a rigid α/β protein at 300 K and at 380 K in solution. These nonlinear excitations arise from the anharmonicity of the protein dynamics. The ILMs were detected by computing the Shannon entropy of the protein main-chain fluctuations. In the non-native state (significantly explored at 380 K), the probability of their excitation was increased by a factor between 9 and 28 for the fast-folder proteins and by a factor 2 for the rigid protein. This enhancement in the non-native state was due to glycine, as demonstrated by simulations in which glycine was mutated to alanine. These ILMs might play a functional role in the flexible regions of proteins and in proteins in a non-native state (i.e. misfolded or unfolded states). PMID:26658321

  8. Intrinsically photosensitive retinal ganglion cells.

    PubMed

    Do, Michael Tri Hoang; Yau, King-Wai

    2010-10-01

    Life on earth is subject to alternating cycles of day and night imposed by the rotation of the earth. Consequently, living things have evolved photodetective systems to synchronize their physiology and behavior with the external light-dark cycle. This form of photodetection is unlike the familiar "image vision," in that the basic information is light or darkness over time, independent of spatial patterns. "Nonimage" vision is probably far more ancient than image vision and is widespread in living species. For mammals, it has long been assumed that the photoreceptors for nonimage vision are also the textbook rods and cones. However, recent years have witnessed the discovery of a small population of retinal ganglion cells in the mammalian eye that express a unique visual pigment called melanopsin. These ganglion cells are intrinsically photosensitive and drive a variety of nonimage visual functions. In addition to being photoreceptors themselves, they also constitute the major conduit for rod and cone signals to the brain for nonimage visual functions such as circadian photoentrainment and the pupillary light reflex. Here we review what is known about these novel mammalian photoreceptors. PMID:20959623

  9. N-dimensional measurement-device-independent quantum key distribution with N + 1 un-characterized sources: zero quantum-bit-error-rate case

    PubMed Central

    Hwang, Won-Young; Su, Hong-Yi; Bae, Joonwoo

    2016-01-01

    We study N-dimensional measurement-device-independent quantum-key-distribution protocol where one checking state is used. Only assuming that the checking state is a superposition of other N sources, we show that the protocol is secure in zero quantum-bit-error-rate case, suggesting possibility of the protocol. The method may be applied in other quantum information processing. PMID:27452275

  10. N-dimensional measurement-device-independent quantum key distribution with N + 1 un-characterized sources: zero quantum-bit-error-rate case.

    PubMed

    Hwang, Won-Young; Su, Hong-Yi; Bae, Joonwoo

    2016-01-01

    We study N-dimensional measurement-device-independent quantum-key-distribution protocol where one checking state is used. Only assuming that the checking state is a superposition of other N sources, we show that the protocol is secure in zero quantum-bit-error-rate case, suggesting possibility of the protocol. The method may be applied in other quantum information processing. PMID:27452275

  11. Intrinsic bioremediation of landfills interim report

    SciTech Connect

    Brigmon, R.L.; Fliermans, C.B.

    1997-07-14

    Intrinsic bioremediation is a risk management option that relies on natural biological and physical processes to contain the spread of contamination from a source. Evidence is presented in this report that intrinsic bioremediation is occurring at the Sanitary Landfill is fundamental to support incorportion into a Corrective Action Plan (CAP).

  12. Separating Scattering from Intrinsic Attenuation

    NASA Astrophysics Data System (ADS)

    van Wijk, K.; Scales, J. A.

    2003-12-01

    The subsurface appears disordered at all length-scales. Therefore, wave propatation at seismic or ultrasonic frequencies is subject to complicated scatterings. A pulse propagating in the subsurface loses energy at each scattering off an impedance contrast, but also decreases in amplitude as the impulse interacts with fluids in the rock. We call the latter non-elastic effect "intrinsic Q", while the former is "scattering Q". It is often the fluids in the rocks that are of interest, but conventional reflection and transmission of the incident pulse only cannot deceipher the individual components of Q due to scattering and fluid movement in the pore-space. We present an approach that can unravel these two mechanisms, allowing a separate estimate of absorption. This method treats the propagation of the average intensity in the framework of radiative transfer (RT); the arrival of (what is left of) the incident pulse is modeled as the coherent energy, whereas the later arriving multiply scattered events form the incoherent intensity. The coherent pulse decays exponentially due to a combination of scattering and absorption, and so does the incoherent intensity. However, multiple scattering can re-direct energy back to the receiver, supplying a gain-term at later times that makes up the incoherent intensity. Strictly speaking, one can invert for scattering and absorption from the intensity at late times only, often modeled with the late-time equivalent of RT, diffusion. However, we will show that fitting both early- and late-time signal with RT constrains absorption and scattering constants more rigorously. These ideas are illustrated by laboratory and sonic-logging measurements.

  13. Mortality anxiety as a function of intrinsic religiosity and perceived purpose in life.

    PubMed

    Hui, Victoria Ka-Ying; Fung, Helene H

    2009-01-01

    Fear of dying and death may be universal, but individuals differ in their emotional reactions to dying and death. The present study included a sample of 133 Chinese university students who were Christians. The authors tested a mediation model which posited that intrinsic religiosity, but not extrinsic religiosity, lowered anxiety toward the dying and death of self and someone close through fostering perceived purpose in life. Structural Equation Modeling results supported a partial mediating role of purpose in life. Moreover, participants were more anxious toward the dying and death of someone close than those of themselves. Discussion focuses on the protective role of intrinsic religiosity on dying and death anxiety.

  14. Intrinsic structure in Saturn's rings

    NASA Astrophysics Data System (ADS)

    Albers, N.

    2015-10-01

    Saturn's rings are the most prominent in our Solar system and one example of granular matter in space. Dominated by tides and inelastic collisions the system is highly flattened being almost 300000km wide while only tens of meters thick. Individual particles are composed of primarily water ice and range from microns to few tens of meters in size. Apparent patterns comprise ringlets, gaps, kinematic wakes, propellers, bending waves, and the winding spiral arms of density waves. These large-scale structures are perturbations foremost created by external as well as embedded moons. Observations made by the Cassini spacecraft currently in orbit around Saturn show these structures in unprecedented detail. But high-resolution measurements reveal the presence of small-scale structures throughout the system. These include self-gravity wakes (50-100m), overstable waves (100-300m), subkm structure at the A and B ring edges, "straw" and "ropy" structures (1-3km), and the C ring "ghosts". Most of these had not been anticipated and are found in perturbed regions, driven by resonances with external moons, where the system undergoes periodic phases of compression and relaxation that correlate with the presence of structure. High velocity dispersion and the presence of large clumps imply structure formation on time scales as short as one orbit (about 10 hours). The presence of these intrinsic structures is seemingly the response to varying local conditions such as internal density, optical depth, underlying particle size distribution, granular temperature, and distance from the central planet. Their abundance provides evidence for an active and dynamic ring system where aggregation and fragmentation are ongoing on orbital timescales. Thus a kinetic description of the rings may be more appropriate than the fluid one. I will present Cassini Ultraviolet Spectrometer (UVIS) High Speed Photometer (HSP) occultations, Voyager 1 and 2 Imaging Science Subsystem (ISS), and high

  15. Algebraic description of intrinsic modes in nuclei

    SciTech Connect

    Leviatan, A.

    1989-01-01

    We present a procedure for extracting normal modes in algebraic number-conserving systems of interacting bosons relevant for collective states in even-even nuclei. The Hamiltonian is resolved into intrinsic (bandhead related) and collective (in-band related) parts. Shape parameters are introduced through non-spherical boson bases. Intrinsic modes decoupled from the spurious modes are obtained from the intinsic part of the Hamiltonian in the limit of large number of bosons. Intrinsic states are constructed and serve to evaluate electromagnetic transition rates. The method is illustrated for systems with one type of boson as well as with proton-neutron bosons. 28 refs., 1 fig.

  16. Intrinsic uncertainty on the nature of dark energy

    NASA Astrophysics Data System (ADS)

    Valkenburg, Wessel; Kunz, Martin; Marra, Valerio

    2013-12-01

    We argue that there is an intrinsic noise on measurements of the equation of state parameter w = p/ρ from large-scale structure around us. The presence of the large-scale structure leads to an ambiguity in the definition of the background universe and thus there is a maximal precision with which we can determine the equation of state of dark energy. To study the uncertainty due to local structure, we model density perturbations stemming from a standard inflationary power spectrum by means of the exact Lemaître-Tolman-Bondi solution of Einstein’s equation, and show that the usual distribution of matter inhomogeneities in a ΛCDM cosmology causes a variation of w - as inferred from distance measures - of several percent. As we observe only one universe, or equivalently because of the cosmic variance, this uncertainty is systematic in nature.

  17. The intrinsic resistome of bacterial pathogens

    PubMed Central

    Olivares, Jorge; Bernardini, Alejandra; Garcia-Leon, Guillermo; Corona, Fernando; B. Sanchez, Maria; Martinez, Jose L.

    2013-01-01

    Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyze recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice. PMID:23641241

  18. Refining the intrinsic chimera flap: a review.

    PubMed

    Agarwal, Jayant P; Agarwal, Shailesh; Adler, Neta; Gottlieb, Lawrence J

    2009-10-01

    Reconstruction of complex tissue deficiencies in which each missing component is in a different spatial relationship to each other can be particularly challenging, especially in patients with limited recipient vessels. The chimera flap design is uniquely suited to reconstruct these deformities. Chimera flaps have been previously defined in many ways with 2 main categories: prefabricated or intrinsic. Herein we attempt to clarify the definition of a true intrinsic chimeric flap and provide examples of how these constructs provide a method for reconstruction of complex defects. The versatility of the intrinsic chimera flap and its procurement from 7 different vascular systems is described. A clarification of the definition of a true intrinsic chimera flap is described. In addition, construction of flaps from the lateral femoral circumflex, deep circumflex iliac, inferior gluteal, peroneal, subscapular, thoracodorsal, and radial arterial systems is described to showcase the versatility of these chimera flaps. A true intrinsic chimera flap must consist of more than a single tissue type. Each of the tissue components receives its blood flow from separate vascular branches or perforators that are connected to a single vascular source. These vascular branches must be of appropriate length to allow for insetting with 3-dimensional spatial freedom. There are a multitude of sites from which true intrinsic chimera flaps may be harvested.

  19. Stimulating Students' Intrinsic Motivation for Learning Chemistry through the Use of Context-Based Learning Modules

    ERIC Educational Resources Information Center

    Vaino, Katrin; Holbrook, Jack; Rannikmae, Miia

    2012-01-01

    This paper introduces a research project in which five chemistry teachers, working in cooperation with university researchers, implemented a new teaching approach using context-based modules specially designed to stimulate the intrinsic motivation of students. The intention was to induce change in chemistry teachers' teaching approach from more…

  20. Achievement-Based Rewards and Intrinsic Motivation: A Test of Cognitive Mediators

    ERIC Educational Resources Information Center

    Cameron, Judy; Pierce, W. David; Banko, Katherine M.; Gear, Amber

    2005-01-01

    This study assessed how rewards impacted intrinsic motivation when students were rewarded for achievement while learning an activity, for performing at a specific level on a test, or for both. Undergraduate university students engaged in a problem-solving activity. The design was a 2 * 2 factorial with 2 levels of reward in a learning phase…

  1. The Effects of Blended Learning on the Intrinsic Motivation of Thai EFL Students

    ERIC Educational Resources Information Center

    Sucaromana, Usaporn

    2013-01-01

    The aim of this study is to compare the results of blended learning with face-to-face learning among university students studying English as a foreign language. The participants were separated by gender, and the following variables, intrinsic motivation for learning English, attitudes towards English as a subject, and satisfaction with the…

  2. Intrinsic delay of permeable base transistor

    SciTech Connect

    Chen, Wenchao; Guo, Jing; So, Franky

    2014-07-28

    Permeable base transistors (PBTs) fabricated by vacuum deposition or solution process have the advantages of easy fabrication and low power operation and are a promising device structure for flexible electronics. Intrinsic delay of PBT, which characterizes the speed of the transistor, is investigated by solving the three-dimensional Poisson equation and drift-diffusion equation self-consistently using finite element method. Decreasing the emitter thickness lowers the intrinsic delay by improving on-current, and a thinner base is also preferred for low intrinsic delay because of fewer carriers in the base region at off-state. The intrinsic delay exponentially decreases as the emitter contact Schottky barrier height decreases, and it linearly depends on the carrier mobility. With an optimized emitter contact barrier height and device geometry, a sub-nano-second intrinsic delay can be achieved with a carrier mobility of ∼10 cm{sup 2}/V/s obtainable in solution processed indium gallium zinc oxide, which indicates the potential of solution processed PBTs for GHz operations.

  3. Genome-Wide Prediction of Intrinsic Disorder; Sequence Alignment of Intrinsically Disordered Proteins

    ERIC Educational Resources Information Center

    Midic, Uros

    2012-01-01

    Intrinsic disorder (ID) is defined as a lack of stable tertiary and/or secondary structure under physiological conditions in vitro. Intrinsically disordered proteins (IDPs) are highly abundant in nature. IDPs possess a number of crucial biological functions, being involved in regulation, recognition, signaling and control, e.g. their functional…

  4. Intrinsic plasticity: an emerging player in addiction.

    PubMed

    Kourrich, Saïd; Calu, Donna J; Bonci, Antonello

    2015-03-01

    Exposure to drugs of abuse, such as cocaine, leads to plastic changes in the activity of brain circuits, and a prevailing view is that these changes play a part in drug addiction. Notably, there has been intense focus on drug-induced changes in synaptic excitability and much less attention on intrinsic excitability factors (that is, excitability factors that are remote from the synapse). Accumulating evidence now suggests that intrinsic factors such as K+ channels are not only altered by cocaine but may also contribute to the shaping of the addiction phenotype.

  5. Bootstrapped models for intrinsic random functions

    SciTech Connect

    Campbell, K.

    1988-08-01

    Use of intrinsic random function stochastic models as a basis for estimation in geostatistical work requires the identification of the generalized covariance function of the underlying process. The fact that this function has to be estimated from data introduces an additional source of error into predictions based on the model. This paper develops the sample reuse procedure called the bootstrap in the context of intrinsic random functions to obtain realistic estimates of these errors. Simulation results support the conclusion that bootstrap distributions of functionals of the process, as well as their kriging variance, provide a reasonable picture of variability introduced by imperfect estimation of the generalized covariance function.

  6. Bootstrapped models for intrinsic random functions

    SciTech Connect

    Campbell, K.

    1987-01-01

    The use of intrinsic random function stochastic models as a basis for estimation in geostatistical work requires the identification of the generalized covariance function of the underlying process, and the fact that this function has to be estimated from the data introduces an additional source of error into predictions based on the model. This paper develops the sample reuse procedure called the ''bootstrap'' in the context of intrinsic random functions to obtain realistic estimates of these errors. Simulation results support the conclusion that bootstrap distributions of functionals of the process, as well as of their ''kriging variance,'' provide a reasonable picture of the variability introduced by imperfect estimation of the generalized covariance function.

  7. The intrinsic quasar luminosity function: Accounting for accretion disk anisotropy

    SciTech Connect

    DiPompeo, M. A.; Myers, A. D.; Brotherton, M. S.; Runnoe, J. C.; Green, R. F.

    2014-05-20

    Quasar luminosity functions are a fundamental probe of the growth and evolution of supermassive black holes. Measuring the intrinsic luminosity function is difficult in practice, due to a multitude of observational and systematic effects. As sample sizes increase and measurement errors drop, characterizing the systematic effects is becoming more important. It is well known that the continuum emission from the accretion disk of quasars is anisotropic—in part due to its disk-like structure—but current luminosity function calculations effectively assume isotropy over the range of unobscured lines of sight. Here, we provide the first steps in characterizing the effect of random quasar orientations and simple models of anisotropy on observed luminosity functions. We find that the effect of orientation is not insignificant and exceeds other potential corrections such as those from gravitational lensing of foreground structures. We argue that current observational constraints may overestimate the intrinsic luminosity function by as much as a factor of ∼2 on the bright end. This has implications for models of quasars and their role in the universe, such as quasars' contribution to cosmological backgrounds.

  8. Electric Field Effect in Intrinsic Josephson Junctions

    NASA Astrophysics Data System (ADS)

    Koyama, T.

    The electric field effect in intrinsic Josephson junction stacks (IJJ's) is investigated on the basis of the capacitively-coupled IJJ model. We clarify the current-voltage characteristics of the IJJ's in the presence of an external electric field. It is predicted that the IJJ's show a dynamical transition to the voltage state as the external electric field is increased.

  9. TOPICAL REVIEW: Intrinsic Josephson junctions: recent developments

    NASA Astrophysics Data System (ADS)

    Yurgens, A. A.

    2000-08-01

    Some recent developments in the fabrication of intrinsic Josephson junctions (IJJ) and their application for studying high-temperature superconductors are discussed. The major advantages of IJJ and unsolved problems are outlined. The feasibility of three-terminal devices based on the stacked IJJ is briefly evaluated.

  10. Intrinsic and Extrinsic Motivation among Collegiate Instrumentalists

    ERIC Educational Resources Information Center

    Diaz, Frank M.

    2010-01-01

    The purpose of this study was to gather and compare information on measures of intrinsic and extrinsic motivation among instrumentalists enrolled in collegiate ensembles. A survey instrument was developed to gather information concerning demographic data and responses to questions on motivational preference. Participants were undergraduate and…

  11. Disrupted Intrinsic Local Synchronization in Poststroke Aphasia.

    PubMed

    Yang, Mi; Li, Jiao; Yao, Dezhong; Chen, Huafu

    2016-03-01

    Evidence has accumulated from the task-related and task-free (i.e., resting state) studies that alternations of intrinsic neural networks exist in poststroke aphasia (PSA) patients. However, information is lacking on the changes in the local synchronization of spontaneous functional magnetic resonance imaging blood-oxygen level-dependent fluctuations in PSA at rest. We investigated the altered intrinsic local synchronization using regional homogeneity (ReHo) on PSA (n = 17) and age- and sex-matched healthy controls (HCs) (n = 20). We examined the correlations between the abnormal ReHo values and the aphasia severity and language performance in PSA. Compared with HCs, the PSA patients exhibited decreased intrinsic local synchronization in the right lingual gyrus, the left calcarine, the left cuneus, the left superior frontal gyrus (SFG), and the left medial of SFG. The local synchronization (ReHo value) in the left medial of SFG was positively correlated with aphasia severity (r = 0.55, P = 0.027) and the naming scores of Aphasia Battery of Chinese (r = 0.66, P = 0.005). This result is consistent with the important role of this value in language processing even in the resting state. The pathogenesis of PSA may be attributed to abnormal intrinsic local synchronous in multiple brain regions. PMID:26986152

  12. Advancing polymers of intrinsic microporosity by mechanochemistry

    SciTech Connect

    Zhang, Pengfei; Jiang, Xueguang; Wan, Shun; Dai, Sheng

    2015-02-20

    Herein, we report a fast (15 min) and solvent-free mechanochemical approach to construct polymers of intrinsic microporosity (PIMs) with high molecular mass and low polydispersity by solid grinding. The enhanced reaction efficiency results from the instantaneous frictional heating and continuous exposure of active sites within those solid reactants.

  13. Intrinsic novobiocin resistance in Staphylococcus saprophyticus.

    PubMed

    Vickers, Anna A; Chopra, Ian; O'Neill, Alex J

    2007-12-01

    Intrinsic novobiocin resistance in Staphylococcus saprophyticus was associated with expression of a novobiocin-resistant form of the drug target protein (GyrB). Site-directed mutagenesis established that resistance depends upon the presence of two specific amino acid residues in GyrB: a glycine at position 85 and a lysine at position 140.

  14. Electroneutral intrinsic point defects in cadmium chalcogenides

    SciTech Connect

    Kharif, Ya.L.; Kudryashov, N.I.; Strunilina, T.A.

    1987-12-01

    Low-mobility electrically neutral intrinsic point defects were observed in cadmium chalcogenides. It was shown that the concentration of these defects is proportional to the cadmium vapor pressure to the 1/3 power at a constant temperature, and a mechanism for the formation of these defects were proposed.

  15. The Intrinsic Connectome of the Rat Amygdala

    PubMed Central

    Schmitt, Oliver; Eipert, Peter; Philipp, Konstanze; Kettlitz, Richard; Fuellen, Georg; Wree, Andreas

    2012-01-01

    The connectomes of nervous systems or parts there of are becoming important subjects of study as the amount of connectivity data increases. Because most tract-tracing studies are performed on the rat, we conducted a comprehensive analysis of the amygdala connectome of this species resulting in a meta-study. The data were imported into the neuroVIISAS system, where regions of the connectome are organized in a controlled ontology and network analysis can be performed. A weighted digraph represents the bilateral intrinsic (connections of regions of the amygdala) and extrinsic (connections of regions of the amygdala to non-amygdaloid regions) connectome of the amygdala. Its structure as well as its local and global network parameters depend on the arrangement of neuronal entities in the ontology. The intrinsic amygdala connectome is a small-world and scale-free network. The anterior cortical nucleus (72 in- and out-going edges), the posterior nucleus (45), and the anterior basomedial nucleus (44) are the nuclear regions that posses most in- and outdegrees. The posterior nucleus turns out to be the most important nucleus of the intrinsic amygdala network since its Shapley rate is minimal. Within the intrinsic amygdala, regions were determined that are essential for network integrity. These regions are important for behavioral (processing of emotions and motivation) and functional (memory) performances of the amygdala as reported in other studies. PMID:23248583

  16. Visual stimuli recruit intrinsically generated cortical ensembles.

    PubMed

    Miller, Jae-eun Kang; Ayzenshtat, Inbal; Carrillo-Reid, Luis; Yuste, Rafael

    2014-09-23

    The cortical microcircuit is built with recurrent excitatory connections, and it has long been suggested that the purpose of this design is to enable intrinsically driven reverberating activity. To understand the dynamics of neocortical intrinsic activity better, we performed two-photon calcium imaging of populations of neurons from the primary visual cortex of awake mice during visual stimulation and spontaneous activity. In both conditions, cortical activity is dominated by coactive groups of neurons, forming ensembles whose activation cannot be explained by the independent firing properties of their contributing neurons, considered in isolation. Moreover, individual neurons flexibly join multiple ensembles, vastly expanding the encoding potential of the circuit. Intriguingly, the same coactive ensembles can repeat spontaneously and in response to visual stimuli, indicating that stimulus-evoked responses arise from activating these intrinsic building blocks. Although the spatial properties of stimulus-driven and spontaneous ensembles are similar, spontaneous ensembles are active at random intervals, whereas visually evoked ensembles are time-locked to stimuli. We conclude that neuronal ensembles, built by the coactivation of flexible groups of neurons, are emergent functional units of cortical activity and propose that visual stimuli recruit intrinsically generated ensembles to represent visual attributes. PMID:25201983

  17. Organisational Learning and Employees' Intrinsic Motivation

    ERIC Educational Resources Information Center

    Remedios, Richard; Boreham, Nick

    2004-01-01

    This study examined the effects of organisational learning initiatives on employee motivation. Four initiatives consistent with theories of organisational learning were a priori ranked in terms of concepts that underpin intrinsic-motivation theory. Eighteen employees in a UK petrochemical company were interviewed to ascertain their experiences of…

  18. Disrupted Intrinsic Local Synchronization in Poststroke Aphasia

    PubMed Central

    Yang, Mi; Li, Jiao; Yao, Dezhong; Chen, Huafu

    2016-01-01

    Abstract Evidence has accumulated from the task-related and task-free (i.e., resting state) studies that alternations of intrinsic neural networks exist in poststroke aphasia (PSA) patients. However, information is lacking on the changes in the local synchronization of spontaneous functional magnetic resonance imaging blood–oxygen level-dependent fluctuations in PSA at rest. We investigated the altered intrinsic local synchronization using regional homogeneity (ReHo) on PSA (n = 17) and age- and sex-matched healthy controls (HCs) (n = 20). We examined the correlations between the abnormal ReHo values and the aphasia severity and language performance in PSA. Compared with HCs, the PSA patients exhibited decreased intrinsic local synchronization in the right lingual gyrus, the left calcarine, the left cuneus, the left superior frontal gyrus (SFG), and the left medial of SFG. The local synchronization (ReHo value) in the left medial of SFG was positively correlated with aphasia severity (r = 0.55, P = 0.027) and the naming scores of Aphasia Battery of Chinese (r = 0.66, P = 0.005). This result is consistent with the important role of this value in language processing even in the resting state. The pathogenesis of PSA may be attributed to abnormal intrinsic local synchronous in multiple brain regions. PMID:26986152

  19. Intrinsic Motivation, Organizational Justice, and Creativity

    ERIC Educational Resources Information Center

    Hannam, Kalli; Narayan, Anupama

    2015-01-01

    For employees to generate creative ideas that are not only original, but also useful to their company, they must interact with their workplace environment to determine organizational needs. Therefore, it is important to consider aspects of the individual as well as their environment when studying creativity. Intrinsic motivation, a predictor of…

  20. Sex Differences, Positive Feedback and Intrinsic Motivation.

    ERIC Educational Resources Information Center

    Deci, Edward L.; And Others

    The paper presents two experiments which test the "change in feelings of competence and self-determination" proposition of cognitive evaluation theory. This proposition states that when a person receives feedback about his performance on an intrinsically motivated activity this information will affect his sense of competence and…

  1. Effects of Reinforcemnt Programs on Intrinsic Motivation.

    ERIC Educational Resources Information Center

    Sushinsky, Leonard W.

    Attribution Theory has led to predictions that the use of material reward may impair intrinsic motivation in the rewarded activity (decreased play effects). A review of the pertinent literature reveals, however, (a) that attribution research has failed to reliably demonstrate that decreased play effects occur in minimal-trial studies (b) that for…

  2. Simple intrinsic defects in InAs :

    SciTech Connect

    Schultz, Peter Andrew

    2013-03-01

    This Report presents numerical tables summarizing properties of intrinsic defects in indium arsenide, InAs, as computed by density functional theory using semi-local density functionals, intended for use as reference tables for a defect physics package in device models.

  3. [From physics to biology: the intrinsic dynamics of the cosmos].

    PubMed

    González de Posada, Francisco

    2003-01-01

    The History of Universe is described in an extremely summarized manner through the use of graphics, from Big bang until today. This is done according to the most recent standard models of Cosmology and Physics of elementary particles; in other words, according to those fields in Physics of a presupposed universal reference. The History of Life is immersed in this universal physical context, in a frame where our knowledge from Geology and Biology can be only terrestrial. The underlying ideas we try to arise are: 1) the transition from a relatively elementary structure to a posterior and a relatively more complex one requires some very special "environmental" conditions; and 2) the new structure can not be described only through its materic constituents, because in cosmic dynamicity new structures and new relationships (of intrinsic respectivity) arise, together with new laws (of extrinsic respectivity). Consequently and as an objective, physical knowledge (for example, elementary particles or atoms) alone in no way can explain biological reality (for example, cell or man).

  4. The intrinsic heterogeneity of superconductivity in the cuprates

    NASA Astrophysics Data System (ADS)

    Shengelaya, A.; Müller, K. A.

    2015-01-01

    In the hole-doped, high-temperature superconducting cuprates, an intrinsic heterogeneity is found, from the early observations to recent data. Below optimum doping, the heterogeneity consists of dynamic metallic and, at low temperatures, superconducting regions in the form of clusters or stripes, which develop and decay as a function of time and location in the antiferromagnetic lattice. This behaviour is underlined by the interesting linear relation between the oxygen isotope shifts of the magnetic penetration depth and the critical temperature with a slope that is a factor 2 larger than expected for the homogeneous distribution of superfluid density. Allusion is also made to the Bose-Einstein condensation reported in structurally heterogeneous, polycrystalline polymer platelets as well as especially to the heterogeneous distribution of visible and dark matter in the Universe, which point to a change of paradigm in modern physics.

  5. Diffuse intrinsic pontine glioma: time for therapeutic optimism.

    PubMed

    Khatua, Soumen; Zaky, Wafik

    2014-01-01

    Diffuse intrinsic pontine glioma (DIPG) is an aggressive tumor that is universally fatal, and to-date we are at a virtual standstill in improving its grim prognosis. Dearth of tissue due to rarity of biopsy has precluded understanding the elusive biology and frustration continues in reproducing faithful animal models for translational research. Furthermore the intricate anatomy of the pons has forestalled locoregional therapy and drug penetration. Over the last few years, biopsy-driven targeted therapy, development of vitro and xenograft animal models for therapeutic testing, profiling immunotherapeutic strategies and locoregional infusion of drugs in brain stem tumors, now provide a sense of hope in the years ahead. This review aims to discuss current status and advances in the management of these tumors.

  6. The intrinsic alignment of galaxies and its impact on weak gravitational lensing in an era of precision cosmology

    NASA Astrophysics Data System (ADS)

    Troxel, M. A.; Ishak, Mustapha

    2015-02-01

    The wealth of incoming and future cosmological observations will allow us to map out the structure and evolution of the observable universe to an unprecedented level of precision. Among these observations is the weak gravitational lensing of galaxies, e.g., cosmic shear that measures the minute distortions of background galaxy images by intervening cosmic structure. Weak lensing and cosmic shear promise to be a powerful probe of astrophysics and cosmology, constraining models of dark energy, measuring the evolution of structure in the universe, and testing theories of gravity on cosmic scales. However, the intrinsic alignment of galaxies-their shape and orientation before being lensed-may pose a great challenge to the use of weak gravitational lensing as an accurate cosmological probe, and has been identified as one of the primary physical systematic biases in cosmic shear studies. Correlations between this intrinsic alignment and the lensing signal can persist even for large physical separations, and isolating the effect of intrinsic alignment from weak lensing is not trivial. A great deal of work in the last two decades has been devoted to understanding and characterizing this intrinsic alignment, which is also a direct and complementary probe of structure formation and evolution in its own right. In this review, we report in a systematic way the state of our understanding of the intrinsic alignment of galaxies, with a particular emphasis on its large-scale impact on weak lensing measurements and methods for its isolation or mitigation. We begin with an introduction to the use of cosmic shear as a probe for cosmology and describe the various physical contributions by intrinsic alignment to the shear or convergence 2- and 3-point correlations. We then review developments in the modeling of the intrinsic alignment signal, including a trend toward attempting to incorporate more accurate nonlinear and single halo effects. The impact on cosmological constraints by the

  7. Cachexia - an intrinsic factor in wound healing.

    PubMed

    Ng, Michael F Y

    2010-04-01

    Systemic diseases are intrinsic factors that alter and may impair the wound healing process. Cachexia is a manifestation of systemic, often chronic, diseases and is characterised by systemic inflammation, appetite suppression and skeletal muscle wasting. Anorexia in cachectic states is commonly associated with malnutrition. Malnutrition may cause impaired healing. Therefore, it would follow that cachexia could influence wound healing because of reduced food intake. However, the lack of response to measures to reverse cachexia, such as supported nutrition, would suggest that a direct causal link between anorexia and weight loss in cachexia is too simple a model. To date, there is no published literature that examines the role of cachexia in human wound healing specifically. This article aims to demonstrate that cachexia is an intrinsic factor in wound healing. The role of the common mediators in wound healing and in cachexia are compared - specifically inflammation, including the nitric oxide synthase pathway, collagen deposition and reepithelialisation.

  8. Intrinsic two-dimensional features as textons

    NASA Technical Reports Server (NTRS)

    Barth, E.; Zetzsche, C.; Rentschler, I.

    1998-01-01

    We suggest that intrinsic two-dimensional (i2D) features, computationally defined as the outputs of nonlinear operators that model the activity of end-stopped neurons, play a role in preattentive texture discrimination. We first show that for discriminable textures with identical power spectra the predictions of traditional models depend on the type of nonlinearity and fail for energy measures. We then argue that the concept of intrinsic dimensionality, and the existence of end-stopped neurons, can help us to understand the role of the nonlinearities. Furthermore, we show examples in which models without strong i2D selectivity fail to predict the correct ranking order of perceptual segregation. Our arguments regarding the importance of i2D features resemble the arguments of Julesz and co-workers regarding textons such as terminators and crossings. However, we provide a computational framework that identifies textons with the outputs of nonlinear operators that are selective to i2D features.

  9. Cell-intrinsic drivers of dendrite morphogenesis

    PubMed Central

    Puram, Sidharth V.; Bonni, Azad

    2013-01-01

    The proper formation and morphogenesis of dendrites is fundamental to the establishment of neural circuits in the brain. Following cell cycle exit and migration, neurons undergo organized stages of dendrite morphogenesis, which include dendritic arbor growth and elaboration followed by retraction and pruning. Although these developmental stages were characterized over a century ago, molecular regulators of dendrite morphogenesis have only recently been defined. In particular, studies in Drosophila and mammalian neurons have identified numerous cell-intrinsic drivers of dendrite morphogenesis that include transcriptional regulators, cytoskeletal and motor proteins, secretory and endocytic pathways, cell cycle-regulated ubiquitin ligases, and components of other signaling cascades. Here, we review cell-intrinsic drivers of dendrite patterning and discuss how the characterization of such crucial regulators advances our understanding of normal brain development and pathogenesis of diverse cognitive disorders. PMID:24255095

  10. Intrinsic remediation of an industrial waste impoundment

    SciTech Connect

    Swindoll, C.M.; Lee, M.D.; Wood, K.N.; Hartten, A.S.; Bishop, A.L.; Connor, J.M.

    1995-12-31

    Intrinsic remediation, also known as natural restoration, was evaluated as a potential corrective action alternative for an industrial surface impoundment previously used for the disposal of waste treatment biosolids, organic wastes, and fly ash. Organic waste constituents included chlorobenzene, aniline, xylenes, benzene, toluene, acetone, p-cresol, 2-butanone, fluorene, and ethylbenzene. The evaluation demonstrated that the impoundment contains an active microbial community including aerobic, denitrifying, sulfate-reducing, and methanogenic microbes, and that environmental conditions were favorable for their growth. Laboratory studies confirmed that these microbes could biodegrade the organic waste constituents under varying redox conditions. The sorptive properties of the residual biosolids and fly ash contribute to the immobilization of chemical constituents and may enhance biodegradation by sequestering chemicals onto surfaces where microbes grow. Based on this field and laboratory evaluation, it was concluded that intrinsic remediation offers significant environmental benefits over other corrective action alternatives that would not allow these natural restoration processes to continue in the surface impoundment.

  11. Extrinsic and intrinsic curvatures in thermodynamic geometry

    NASA Astrophysics Data System (ADS)

    Hosseini Mansoori, Seyed Ali; Mirza, Behrouz; Sharifian, Elham

    2016-08-01

    We investigate the intrinsic and extrinsic curvatures of a certain hypersurface in thermodynamic geometry of a physical system and show that they contain useful thermodynamic information. For an anti-Reissner-Nordström-(A)de Sitter black hole (Phantom), the extrinsic curvature of a constant Q hypersurface has the same sign as the heat capacity around the phase transition points. The intrinsic curvature of the hypersurface can also be divergent at the critical points but has no information about the sign of the heat capacity. Our study explains the consistent relationship holding between the thermodynamic geometry of the KN-AdS black holes and those of the RN (J-zero hypersurface) and Kerr black holes (Q-zero hypersurface) ones [1]. This approach can easily be generalized to an arbitrary thermodynamic system.

  12. Intrinsic emittance reduction in transmission mode photocathodes

    NASA Astrophysics Data System (ADS)

    Lee, Hyeri; Cultrera, Luca; Bazarov, Ivan

    2016-03-01

    High quantum efficiency (QE) and low emittance electron beams provided by multi-alkali photocathodes make them of great interest for next generation high brightness photoinjectors. Spicer's three-step model well describes the photoemission process; however, some photocathode characteristics such as their thickness have not yet been completely exploited to further improve the brightness of the generated electron beams. In this work, we report on the emittance and QE of a multi-alkali photocathode grown onto a glass substrate operated in transmission and reflection modes at different photon energies. We observed a 20% reduction in the intrinsic emittance from the reflection to the transmission mode operation. This observation can be explained by inelastic electron-phonon scattering during electrons' transit towards the cathode surface. Due to this effect, we predict that thicker photocathode layers will further reduce the intrinsic emittance of electron beams generated by photocathodes operated in transmission mode.

  13. Observation of intrinsic inverse spin Hall effect.

    PubMed

    Werake, Lalani K; Ruzicka, Brian A; Zhao, Hui

    2011-03-11

    We report observation of intrinsic inverse spin Hall effect in undoped GaAs multiple quantum wells with a sample temperature of 10 K. A transient ballistic pure spin current is injected by a pair of laser pulses through quantum interference. By time resolving the dynamics of the pure spin current, the momentum relaxation time is deduced, which sets the lower limit of the scattering time between electrons and holes. The transverse charge current generated by the pure spin current via the inverse spin Hall effect is simultaneously resolved. We find that the charge current is generated well before the first electron-hole scattering event. Generation of the transverse current in the scattering-free ballistic transport regime provides unambiguous evidence for the intrinsic inverse spin Hall effect. PMID:21469830

  14. Intrinsic interfacial phenomena in manganite heterostructures

    NASA Astrophysics Data System (ADS)

    Vaz, C. A. F.; Walker, F. J.; Ahn, C. H.; Ismail-Beigi, S.

    2015-04-01

    We review recent advances in our understanding of interfacial phenomena that emerge when dissimilar materials are brought together at atomically sharp and coherent interfaces. In particular, we focus on phenomena that are intrinsic to the interface and review recent work carried out on perovskite manganites interfaces, a class of complex oxides whose rich electronic properties have proven to be a useful playground for the discovery and prediction of novel phenomena.

  15. Moral Distress, Workplace Health, and Intrinsic Harm.

    PubMed

    Weber, Elijah

    2016-05-01

    Moral distress is now being recognized as a frequent experience for many health care providers, and there's good evidence that it has a negative impact on the health care work environment. However, contemporary discussions of moral distress have several problems. First, they tend to rely on inadequate characterizations of moral distress. As a result, subsequent investigations regarding the frequency and consequences of moral distress often proceed without a clear understanding of the phenomenon being discussed, and thereby risk substantially misrepresenting the nature, frequency, and possible consequences of moral distress. These discussions also minimize the intrinsically harmful aspects of moral distress. This is a serious omission. Moral distress doesn't just have a negative impact on the health care work environment; it also directly harms the one who experiences it. In this paper, I claim that these problems can be addressed by first clarifying our understanding of moral distress, and then identifying what makes moral distress intrinsically harmful. I begin by identifying three common mistakes that characterizations of moral distress tend to make, and explaining why these mistakes are problematic. Next, I offer an account of moral distress that avoids these mistakes. Then, I defend the claim that moral distress is intrinsically harmful to the subject who experiences it. I conclude by explaining how acknowledging this aspect of moral distress should reshape our discussions about how best to deal with this phenomenon. PMID:26308751

  16. Intrinsic Mean Square Displacement in Proteins

    NASA Astrophysics Data System (ADS)

    Vural, Derya; Glyde, Henry R.

    2012-02-01

    The dynamics of biological molecules is investigated in neutron scattering experiments, in molecular dynamics simulations, and using analytical theory. Specifically, the mean square displacement (MSD), exp, of hydrogen in proteins is determined from measurements of the incoherent elastic neutron scattering intensity (ENSI). The MSD, exp, is usually obtained from the dependence of the ENSI on the scattering wave vector Q. The MSD increases with increasing temperature reaching large values at room temperature. Large MSD is often associated with and used as an indicator of protein function. The observed MSD, however, depends on the energy resolution of the neutron spectrometer employed. We present a method, a first attempt, to extract the intrinsic MSD of hydrogen in protein from measurements, one that is independent of the instrument resolution. The method consists of a model of the ENSI that contains (1) the intrinsic MSD, (2) the instrument resolution width and (3) a parameter describing the motional processes that contribute to the MSD. Several examples of intrinsic MSDs in proteins obtained from fitting to data in the existing literature will be presented.

  17. Learning intrinsic excitability in medium spiny neurons

    PubMed Central

    Scheler, Gabriele

    2014-01-01

    We present an unsupervised, local activation-dependent learning rule for intrinsic plasticity (IP) which affects the composition of ion channel conductances for single neurons in a use-dependent way. We use a single-compartment conductance-based model for medium spiny striatal neurons in order to show the effects of parameterization of individual ion channels on the neuronal membrane potential-curent relationship (activation function). We show that parameter changes within the physiological ranges are sufficient to create an ensemble of neurons with significantly different activation functions. We emphasize that the effects of intrinsic neuronal modulation on spiking behavior require a distributed mode of synaptic input and can be eliminated by strongly correlated input. We show how modulation and adaptivity in ion channel conductances can be utilized to store patterns without an additional contribution by synaptic plasticity (SP). The adaptation of the spike response may result in either "positive" or "negative" pattern learning. However, read-out of stored information depends on a distributed pattern of synaptic activity to let intrinsic modulation determine spike response. We briefly discuss the implications of this conditional memory on learning and addiction. PMID:25520776

  18. Etiology of dental erosion--intrinsic factors.

    PubMed

    Scheutzel, P

    1996-04-01

    Dental erosion due to intrinsic factors is caused by gastric acid reaching the oral cavity and the teeth as a result of vomiting or gastroesophageal reflux. Since clinical manifestation of dental erosion does not occur until gastric acid has acted on the dental hard tissues regularly over a period of several years, dental erosion caused by intrinsic factors has been observed only in those diseases which are associated with chronic vomiting or persistent gastroesophageal reflux over a long period. Examples of such conditions include disorders of the upper alimentary tract, specific metabolic and endocrine disorders, cases of medication side-effects and drug abuse, and certain psychosomatic disorders, e.g. stress-induced psychosomatic vomiting, anorexia and bulimia nervosa or rumination. Based on a review of the medical and dental literature, the main symptoms of all disorders which must be taken into account as possible intrinsic etiological factors of dental erosion are thoroughly discussed with respect to the clinical picture, prevalence and risk of erosion.

  19. Correlation between Intrinsic Patellofemoral Pain Syndrome in Young Adults and Lower Extremity Biomechanics

    PubMed Central

    Kwon, Ohjeoung; Yun, Mijung; Lee, Wanhee

    2014-01-01

    [Purpose] The purpose of this study was to evaluate the correlation between intrinsic patellofemoral pain syndrome (PFPS) in young adults and lower extremity biomechanics. [Subjects] This experiment was carried out with sixty (24 men and 32 women), who are normal university students as subjects. [Methods] All subjects underwent 3 clinical evaluations. For distinguishing the intrinsic PFPS from controls, we used the Modified Functional Index Questionnaire (MFIQ), Clarke’s test and the Eccentric step test. Based on the results of the tests, subjects who were classified as positive for 2 more tests were allocated to the bilateral or unilateral intrinsic PFPS group (n=14), and the others were allocated to the control group (n=42). These two groups were tested for hamstring tightness, foot overpronation, and static Q-angle and dynamic Q-angle. These are the four lower extremity biomechanic, cited as risk factors of patellofemoral pain syndrome. [Results] The over pronation, static Q-angle and the dynamic Q-angle were not significantly different between the two groups. However, the hamstring tightness of the PFPS group was significantly greater than that of the controls. [Conclusion] We examined individuals for intrinsic patellofemoral pain syndrome in young adults and lower extremity biomechanics. We found a strong correlation between intrinsic PFPS and hamstring tightness. PMID:25140074

  20. Phosphorothioate oligonucleotides inhibit the intrinsic tenase complex.

    PubMed

    Sheehan, J P; Lan, H C

    1998-09-01

    Systemic administration of ISIS 2302, a 20-mer antisense phosphorothioate oligonucleotide targeting human intercellular adhesion molecule-1 mRNA, causes prolongation of plasma clotting times in both monkey and human studies. The anticoagulant effects of ISIS 2302 were investigated with both in vitro coagulation assays in human plasma and purified enzyme systems. At high oligonucleotide plasma concentrations (>100 microgram/mL), prolongation of the prothrombin and thrombin times was observed. In a thrombin time assay using purified components, high concentrations of ISIS 2302 inhibited thrombin clotting activity both by stimulating inhibition by heparin cofactor II and directly competing with fibrinogen for binding to anion binding exosite I. In contrast, low concentrations of ISIS 2302 (<100 microgram/mL) showed a selective, linear prolongation of the activated partial thromboplastin time (PTT). The rate limiting effect of 50 microgram/mL ISIS 2302, which prolonged the PTT to 1.5 times control, was identified by sequential modification of the clotting assay. Delaying addition of oligonucleotide until after contact activation failed to correct prolongation of the PTT. The calcium-dependent steps of the intrinsic pathway were individually assessed by adding sufficient activated coagulation factor to correct the PTT in plasma deficient in that specific factor. Addition of factor XIa, IXa, VIIIa, or Va failed to correct the PTT in the presence of ISIS 2302. In contrast, 0.2 nmol/L factor Xa corrected prolongation of the PTT in factor X-deficient plasma with or without oligonucleotide present. ISIS 2302 (50 microgram/mL) did not prolong a modified Russel viper venom time, suggesting no significant inhibition of prothrombinase. Thus, 50 microgram/mL ISIS 2302 prolonged the PTT by selectively inhibiting intrinsic tenase activity. ISIS 2302 showed partial inhibition of intrinsic tenase activity (to approximately 35% of control) at clinically relevant oligonucleotide

  1. Importance and challenges of measuring intrinsic foot muscle strength

    PubMed Central

    2012-01-01

    Background Intrinsic foot muscle weakness has been implicated in a range of foot deformities and disorders. However, to establish a relationship between intrinsic muscle weakness and foot pathology, an objective measure of intrinsic muscle strength is needed. The aim of this review was to provide an overview of the anatomy and role of intrinsic foot muscles, implications of intrinsic weakness and evaluate the different methods used to measure intrinsic foot muscle strength. Method Literature was sourced from database searches of MEDLINE, PubMed, SCOPUS, Cochrane Library, PEDro and CINAHL up to June 2012. Results There is no widely accepted method of measuring intrinsic foot muscle strength. Methods to estimate toe flexor muscle strength include the paper grip test, plantar pressure, toe dynamometry, and the intrinsic positive test. Hand-held dynamometry has excellent interrater and intrarater reliability and limits toe curling, which is an action hypothesised to activate extrinsic toe flexor muscles. However, it is unclear whether any method can actually isolate intrinsic muscle strength. Also most methods measure only toe flexor strength and other actions such as toe extension and abduction have not been adequately assessed. Indirect methods to investigate intrinsic muscle structure and performance include CT, ultrasonography, MRI, EMG, and muscle biopsy. Indirect methods often discriminate between intrinsic and extrinsic muscles, but lack the ability to measure muscle force. Conclusions There are many challenges to accurately measure intrinsic muscle strength in isolation. Most studies have measured toe flexor strength as a surrogate measure of intrinsic muscle strength. Hand-held dynamometry appears to be a promising method of estimating intrinsic muscle strength. However, the contribution of extrinsic muscles cannot be excluded from toe flexor strength measurement. Future research should clarify the relative contribution of intrinsic and extrinsic muscles

  2. 46 CFR 111.105-11 - Intrinsically safe systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... required by this subpart to be intrinsically safe must use approved components meeting UL 913 or IEC 60079-11 (both incorporated by reference; see 46 CFR 110.10-1). (b) Each electric cable of an intrinsically safe system must— (1) Be 50 mm (2 inches) or more from cable of non-intrinsically safe...

  3. 46 CFR 111.105-11 - Intrinsically safe systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... required by this subpart to be intrinsically safe must use approved components meeting UL 913 or IEC 60079-11 (both incorporated by reference; see 46 CFR 110.10-1). (b) Each electric cable of an intrinsically safe system must— (1) Be 50 mm (2 inches) or more from cable of non-intrinsically safe...

  4. The Impact of Teaching Strategies on Intrinsic Motivation.

    ERIC Educational Resources Information Center

    Bomia, Lisa; Beluzo, Lynne; Demeester, Debra; Elander, Keli; Johnson, Mary; Sheldon, Betty

    This paper examines intrinsic motivation by reviewing various motivational theories and models and discussing whether research supports the hypothesis that teaching strategies can influence intrinsic motivation. Intrinsic motivation, also known as self-motivation, refers to influences that originate from within a person which cause a person to act…

  5. Reinforcement, Reward, and Intrinsic Motivation: A Meta-Analysis.

    ERIC Educational Resources Information Center

    Cameron, Judy; Pierce, W. David

    1994-01-01

    A meta-analysis including 96 experimental studies considers the effects of reinforcement/reward on intrinsic motivation. Results indicate that reward does not decrease intrinsic motivation, although interaction effects must be examined. An analysis with five studies also indicates that reinforcement does not harm intrinsic motivation. (SLD)

  6. Intrinsic Motivation: An Overlooked Component for Student Success

    ERIC Educational Resources Information Center

    Augustyniak, Robert A.; Ables, Adrienne Z.; Guilford, Philip; Lujan, Heidi L.; Cortright, Ronald N.; DiCarlo, Stephen E.

    2016-01-01

    Intrinsic motivation to learn involves engaging in learning opportunities because they are seen as enjoyable, interesting, or relevant to meeting one's core psychological needs. As a result, intrinsic motivation is associated with high levels of effort and task performance. Students with greater levels of intrinsic motivation demonstrate strong…

  7. Elements of the Competitive Situation That Affect Intrinsic Motivation.

    ERIC Educational Resources Information Center

    Reeve, Johnmarshall; Deci, Edward L.

    1996-01-01

    Explores the effects of three elements of the competitive situation (competitive set, competitive outcome, and interpersonal context) on intrinsic motivation in a sample of college students (n=100). Competitive outcome and interpersonal context affected intrinsic motivation: winning increased intrinsic motivation, while pressured interpersonal…

  8. William B. Castle and intrinsic factor.

    PubMed

    Kass, L

    1978-12-01

    Fifty years ago, William B. Castle described the properties of intrinsic factor. By so doing, he advanced the first acceptable theory of the pathogenesis and pathophysiology of pernicious anemia. Enveloping Castle's discovery were prevalent ideas in the medical community of the time, such as the importance of nutritional factors in the pathogenesis of disease, and the intriguing possibility that many disorders could be ameliorated or even cured by administration of a "missing" substance. When viewed in a contemporary perspective, Castle's observations of a half century ago are remarkable examples of ingenuity and single-minded dedication to uncovering the pathogenetic mechanism of a previously fatal disorder.

  9. Biophysical characterization of intrinsically disordered proteins

    PubMed Central

    Eliezer, David

    2009-01-01

    Summary The challenges associated with the structural characterization of disordered proteins have resulted in the application of a host of biophysical methods to such systems. NMR spectroscopy is perhaps the most readily suited technique for providing high-resolution structural information on disordered protein states in solution. Optical methods, solid state NMR, ESR and x-ray scattering can also provide valuable information regarding the ensemble of conformations sampled by disordered states. Finally, computational studies have begun to assume an increasingly important role in interpreting and extending the impact of experimental data obtained for such systems. This article discusses recent advances in the applications of these methods to intrinsically disordered proteins. PMID:19162471

  10. Ambipolar quantum dots in intrinsic silicon

    SciTech Connect

    Betz, A. C. Gonzalez-Zalba, M. F.; Podd, G.; Ferguson, A. J.

    2014-10-13

    We electrically measure intrinsic silicon quantum dots with electrostatically defined tunnel barriers. The presence of both p- and n-type ohmic contacts enables the accumulation of either electrons or holes. Thus, we are able to study both transport regimes within the same device. We investigate the effect of the tunnel barriers and the electrostatically defined quantum dots. There is greater localisation of charge states under the tunnel barriers in the case of hole conduction, leading to higher charge noise in the p-type regime.

  11. A method to compute the n-dimensional solid spectral angle between vectors and its use for band selection in hyperspectral data

    NASA Astrophysics Data System (ADS)

    Tian, M.; Feng, J.; Rivard, B.; Zhao, C.

    2016-08-01

    This study presents the calculation of spectral angle beyond two endmember vectors to the n-dimensional solid spectral angle (NSSA). The calculation of the NSSA is used to characterize the local spectral shape difference among a set of endmembers, leading to a methodology for band selection based on spectral shape variations of more than two spectra. Equidistributed sequences used in the quasi-Monte Carlo method (ESMC) for numerical simulations are shown to expedite the calculation of the NSSA. We develop a band selection method using the computation of NSSA(ϑn) in the context of a sliding window. By sliding the window over all bands available for varying band intervals, the calculated solid spectral angle values can capture the similarity of the endmembers over all spectral regions available and for spectral features of varying widths. By selecting a subset of spectral bands with largest solid spectral angles, a methodology can be developed to capture the most important spectral information for the separation or mapping of endmembers. We provide an example of the merits of the NSSA-ESMC method for band selection as applied to linear spectral unmixing. Specifically, we examine the endmember abundance errors resulting from the NSSA band selection method as opposed to using the full spectral dimensionality available.

  12. Intrinsic Josephson Junctions with Intermediate Damping

    NASA Astrophysics Data System (ADS)

    Warburton, Paul A.; Saleem, Sajid; Fenton, Jon C.; Speller, Susie; Grovenor, Chris R. M.

    2011-03-01

    In cuprate superconductors, adjacent cuprate double-planes are intrinsically Josephson-coupled. For bias currents perpendicular to the planes, the current-voltage characteristics correspond to those of an array of underdamped Josephson junctions. We will discuss our experiments on sub-micron Tl-2212 intrinsic Josephson junctions (IJJs). The dynamics of the IJJs at the plasma frequency are moderately damped (Q ~ 8). This results in a number of counter-intuitive observations, including both a suppression of the effect of thermal fluctuations and a shift of the skewness of the switching current distributions from negative to positive as the temperature is increased. Simulations confirm that these phenomena result from repeated phase slips as the IJJ switches from the zero-voltage to the running state. We further show that increased dissipation counter-intuitively increases the maximum supercurrent in the intermediate damping regime (PRL vol. 103, art. no. 217002). We discuss the role of environmental dissipation on the dynamics and describe experiments with on-chip lumped-element passive components in order control the environment seen by the IJJs. Work supported by EPSRC.

  13. Intrinsic adaptation in autonomous recurrent neural networks.

    PubMed

    Marković, Dimitrije; Gros, Claudius

    2012-02-01

    A massively recurrent neural network responds on one side to input stimuli and is autonomously active, on the other side, in the absence of sensory inputs. Stimuli and information processing depend crucially on the quality of the autonomous-state dynamics of the ongoing neural activity. This default neural activity may be dynamically structured in time and space, showing regular, synchronized, bursting, or chaotic activity patterns. We study the influence of nonsynaptic plasticity on the default dynamical state of recurrent neural networks. The nonsynaptic adaption considered acts on intrinsic neural parameters, such as the threshold and the gain, and is driven by the optimization of the information entropy. We observe, in the presence of the intrinsic adaptation processes, three distinct and globally attracting dynamical regimes: a regular synchronized, an overall chaotic, and an intermittent bursting regime. The intermittent bursting regime is characterized by intervals of regular flows, which are quite insensitive to external stimuli, interceded by chaotic bursts that respond sensitively to input signals. We discuss these findings in the context of self-organized information processing and critical brain dynamics. PMID:22091667

  14. Predicting intrinsic disorder from amino acid sequence.

    PubMed

    Obradovic, Zoran; Peng, Kang; Vucetic, Slobodan; Radivojac, Predrag; Brown, Celeste J; Dunker, A Keith

    2003-01-01

    Blind predictions of intrinsic order and disorder were made on 42 proteins subsequently revealed to contain 9,044 ordered residues, 284 disordered residues in 26 segments of length 30 residues or less, and 281 disordered residues in 2 disordered segments of length greater than 30 residues. The accuracies of the six predictors used in this experiment ranged from 77% to 91% for the ordered regions and from 56% to 78% for the disordered segments. The average of the order and disorder predictions ranged from 73% to 77%. The prediction of disorder in the shorter segments was poor, from 25% to 66% correct, while the prediction of disorder in the longer segments was better, from 75% to 95% correct. Four of the predictors were composed of ensembles of neural networks. This enabled them to deal more efficiently with the large asymmetry in the training data through diversified sampling from the significantly larger ordered set and achieve better accuracy on ordered and long disordered regions. The exclusive use of long disordered regions for predictor training likely contributed to the disparity of the predictions on long versus short disordered regions, while averaging the output values over 61-residue windows to eliminate short predictions of order or disorder probably contributed to the even greater disparity for three of the predictors. This experiment supports the predictability of intrinsic disorder from amino acid sequence. PMID:14579347

  15. MRI endoscopy using intrinsically localized probes

    PubMed Central

    Sathyanarayana, Shashank; Bottomley, Paul A.

    2009-01-01

    Magnetic resonance imaging (MRI) is traditionally performed with fixed externally applied gradient magnetic fields and is hence intrinsically locked to the laboratory frame of reference (FoR). Here a method for high-resolution MRI that employs active, catheter-based, tiny internal probes that utilize the spatial properties of the probe itself for localization is proposed and demonstrated at 3 T. Because these properties are intrinsic to the probe, they move with it, transforming MRI from the laboratory FoR to the FoR of the device itself, analogous to an endoscope. The “MRI endoscope” can utilize loop coils and loopless antennas with modified sensitivity, in combination with adiabatic excitation by the device itself, to restrict the MRI sensitivity to a disk-shaped plane a few mm thick. Excitation with the MRI endoscope limits the eddy currents induced in the sample to an excited volume whose size is orders of magnitude below that excited by a conventional body MRI coil. Heat testing shows maximum local temperature increases of <1 °C during MRI, within regulatory guidelines. The method is demonstrated in a kiwifruit, in intact porcine and rabbit aortas, and in an atherosclerotic human iliac artery specimen, with in-plane resolution as small as 80 μm and 1.5–5 mm slice thickness. PMID:19378751

  16. The Neglected Intrinsic Resistome of Bacterial Pathogens

    PubMed Central

    Fajardo, Alicia; Martínez-Martín, Nadia; Mercadillo, María; Galán, Juan C.; Ghysels, Bart; Matthijs, Sandra; Cornelis, Pierre; Wiehlmann, Lutz; Tümmler, Burkhard; Baquero, Fernando; Martínez, José L.

    2008-01-01

    Bacteria with intrinsic resistance to antibiotics are a worrisome health problem. It is widely believed that intrinsic antibiotic resistance of bacterial pathogens is mainly the consequence of cellular impermeability and activity of efflux pumps. However, the analysis of transposon-tagged Pseudomonas aeruginosa mutants presented in this article shows that this phenotype emerges from the action of numerous proteins from all functional categories. Mutations in some genes make P. aeruginosa more susceptible to antibiotics and thereby represent new targets. Mutations in other genes make P. aeruginosa more resistant and therefore define novel mechanisms for mutation-driven acquisition of antibiotic resistance, opening a new research field based in the prediction of resistance before it emerges in clinical environments. Antibiotics are not just weapons against bacterial competitors, but also natural signalling molecules. Our results demonstrate that antibiotic resistance genes are not merely protective shields and offer a more comprehensive view of the role of antibiotic resistance genes in the clinic and in nature. PMID:18286176

  17. Intrinsically disordered proteins drive membrane curvature

    NASA Astrophysics Data System (ADS)

    Busch, David J.; Houser, Justin R.; Hayden, Carl C.; Sherman, Michael B.; Lafer, Eileen M.; Stachowiak, Jeanne C.

    2015-07-01

    Assembly of highly curved membrane structures is essential to cellular physiology. The prevailing view has been that proteins with curvature-promoting structural motifs, such as wedge-like amphipathic helices and crescent-shaped BAR domains, are required for bending membranes. Here we report that intrinsically disordered domains of the endocytic adaptor proteins, Epsin1 and AP180 are highly potent drivers of membrane curvature. This result is unexpected since intrinsically disordered domains lack a well-defined three-dimensional structure. However, in vitro measurements of membrane curvature and protein diffusivity demonstrate that the large hydrodynamic radii of these domains generate steric pressure that drives membrane bending. When disordered adaptor domains are expressed as transmembrane cargo in mammalian cells, they are excluded from clathrin-coated pits. We propose that a balance of steric pressure on the two surfaces of the membrane drives this exclusion. These results provide quantitative evidence for the influence of steric pressure on the content and assembly of curved cellular membrane structures.

  18. Sensory and intrinsic coordination of movement.

    PubMed Central

    Lee, D N; Craig, C M; Grealy, M A

    1999-01-01

    A recently generalized theory of perceptual guidance (general tau theory) was used to analyse coordination in skilled movement. The theory posits that (i) guiding movement entails controlling closure of spatial and/or force gaps between effectors and goals, by sensing and regulating the tau s of the gaps (the time-to-closure at current closure rate), (ii) a principal way of coordinating movements is keeping the tau s of different gaps in constant ratio (known as tau-coupling), and (iii) intrinsically paced movements are guided and coordinated by tau-coupling onto a tau-guide, tau g, generated in the nervous system and described by the equation tau g = 0.5 (t-T 2/t) where T is the duration of the body movement and t is the time from the start of the movement. Kinematic analysis of hand to mouth movements by human adults, with eyes open or closed, indicated that hand guidance was achieved by maintaining, during 80 85% of the movement, the tau-couplings tau alpha-tau r and tau r-tau g, where tau r is tau of the hand-mouth gap, tau alpha is tau of the angular gap to be closed by steering the hand and tau g is an intrinsic tau-guide. PMID:10584340

  19. Characterization of Intrinsic Properties of Promoters

    PubMed Central

    2015-01-01

    Accurate characterization of promoter behavior is essential for the rational design of functional synthetic transcription networks such as logic gates and oscillators. However, transcription rates observed from promoters can vary significantly depending on the growth rate of host cells and the experimental and genetic contexts of the measurement. Furthermore, in vivo measurement methods must accommodate variation in translation, protein folding, and maturation rates of reporter proteins, as well as metabolic load. The external factors affecting transcription activity may be considered to be extrinsic, and the goal of characterization should be to obtain quantitative measures of the intrinsic characteristics of promoters. We have developed a promoter characterization method that is based on a mathematical model for cell growth and reporter gene expression and exploits multiple in vivo measurements to compensate for variation due to extrinsic factors. First, we used optical density and fluorescent reporter gene measurements to account for the effect of differing cell growth rates. Second, we compared the output of reporter genes to that of a control promoter using concurrent dual-channel fluorescence measurements. This allowed us to derive a quantitative promoter characteristic (ρ) that provides a robust measure of the intrinsic properties of a promoter, relative to the control. We imposed different extrinsic factors on growing cells, altering carbon source and adding bacteriostatic agents, and demonstrated that the use of ρ values reduced the fraction of variance due to extrinsic factors from 78% to less than 4%. This is a simple and reliable method to quantitatively describe promoter properties. PMID:26436725

  20. The Mediation Role of Intrinsic and Extrinsic Motivation in the Relationship between Creative Educational Environment and Metacognitive Self-Regulation

    ERIC Educational Resources Information Center

    Maralani, Farnaz Mehdipour

    2016-01-01

    This study investigated the mediation role of intrinsic and extrinsic motivation in the relationship between creative educational environment and metacognitive self-regulation. Participants were 300 girls, selected randomly from the girl hostel in university of Tehran. Participants completed Akoal's creative educational environment questionnaire,…

  1. Intrinsic surface dipole in topological insulators.

    PubMed

    Fregoso, Benjamin M; Coh, Sinisa

    2015-10-28

    We calculate the local density of states of two prototypical topological insulators (Bi2Se3 and Bi2Te2Se) as a function of distance from the surface within density functional theory. We find that, in the absence of disorder or doping, there is a 2 nm thick surface dipole the origin of which is the occupation of the topological surface states above the Dirac point. As a consequence, the bottom of the conduction band is bent upward by about 75 meV near the surface, and there is a hump-like feature associated with the top of the valence band. We expect that band bending will occur in all pristine topological insulators as long as the Fermi level does not cross the Dirac point. Our results show that topological insulators are intrinsic Schottky barrier solar cells.

  2. Measuring Intrinsic Curvature of Space with Electromagnetism

    NASA Astrophysics Data System (ADS)

    Mabin, Mason; Becker, Maria; Batelaan, Herman

    2016-10-01

    The concept of curved space is not readily observable in everyday life. The educational movie "Sphereland" attempts to illuminate the idea. The main character, a hexagon, has to go to great lengths to prove that her world is in fact curved. We present an experiment that demonstrates a new way to determine if a two-dimensional surface, the 2-sphere, is curved. The behavior of an electric field, placed on a spherical surface, is shown to be related to the intrinsic Gaussian curvature. This approach allows students to gain some understanding of Einstein's theory of general relativity, which relates the curvature of spacetime to the presence of mass and energy. Additionally, an opportunity is provided to investigate the dimensionality of Gauss's law.

  3. Structure and Dynamics of Intrinsically Disordered Proteins.

    PubMed

    Fu, Biao; Vendruscolo, Michele

    2015-01-01

    Intrinsically disordered proteins (IDPs) are involved in a wide range of essential biological processes, including in particular signalling and regulation. We are only beginning, however, to develop a detailed knowledge of the structure and dynamics of these proteins. It is becoming increasingly clear that, as IDPs populate highly heterogeneous states, they should be described in terms of conformational ensembles rather than as individual structures, as is instead most often the case for the native states of globular proteins. Within this context, in this chapter we describe the conceptual tools and methodological aspects associated with the description of the structure and dynamics of IDPs in terms of conformational ensembles. A major emphasis is given to methods in which molecular simulations are used in combination with experimental nuclear magnetic resonance (NMR) measurements, as they are emerging as a powerful route to achieve an accurate determination of the conformational properties of IDPs. PMID:26387099

  4. Intrinsic-surface-tag image authentication

    SciTech Connect

    Palm, R.G.; DeVolpi, A.

    1991-12-01

    The objective of this work is to further the development of a unique treaty limited item (TLI) intrinsic surface tag for arms control applications. This tag`s unique feature is the ability to capture the sub-micron scale topography of the TLI surface. The surface topography is captured by plastic castings of the surface as digitally imaged by an electron microscope. Tag authentication is accomplished by comparing digital castings images obtained in two different inspections. Surface replication experiments are described, as these experiments from the basis for the authentication algorithm. Both the experiments and the authentication algorithm are analyzed using the modulation transfer function. Recommendations for future improvements in tag authentication are also suggested by the modulation transfer function analysis. 4 refs.

  5. Intrinsic-surface-tag image authentication

    SciTech Connect

    Palm, R.G.; DeVolpi, A.

    1991-12-01

    The objective of this work is to further the development of a unique treaty limited item (TLI) intrinsic surface tag for arms control applications. This tag's unique feature is the ability to capture the sub-micron scale topography of the TLI surface. The surface topography is captured by plastic castings of the surface as digitally imaged by an electron microscope. Tag authentication is accomplished by comparing digital castings images obtained in two different inspections. Surface replication experiments are described, as these experiments from the basis for the authentication algorithm. Both the experiments and the authentication algorithm are analyzed using the modulation transfer function. Recommendations for future improvements in tag authentication are also suggested by the modulation transfer function analysis. 4 refs.

  6. Tropical cyclone recurvature: An intrinsic property?

    NASA Astrophysics Data System (ADS)

    Chan, Kelvin T. F.; Chan, Johnny C. L.

    2016-08-01

    The typical track of a tropical cyclone (TC) in the Northern Hemisphere is an initial northwestward movement followed by an eventual turning toward the east. Such turning is referred to as recurvature and often explained by the change of the environmental flow that steers the TC. Here we show that even in the absence of background flow, a TC initiated at a high enough latitude can recurve itself. Differential horizontal advection of the planetary vorticity by the TC circulation at different vertical levels leads to the development of vertical wind shear, upper tropospheric anticyclone, and asymmetric distribution of convection. The flow associated with the upper tropospheric anticyclone on the equatorward side of the TC and the diabatic heating associated with the asymmetric convection combine to cause the TC to recurve. Such knowledge, an intrinsic recurvature property of the TC is important in forecasting the TC track when the environmental flow is weak.

  7. The intrinsic nuclear spectrum of NGC 1068

    NASA Technical Reports Server (NTRS)

    Pier, Edward A.; Antonucci, Robert; Hurt, Todd; Kriss, Gerard; Krolik, Julian

    1994-01-01

    We have inferred the intrinsic optical, UV and X-ray continuum of the obscured Seyfert nucleus of NGC 1068, using small aperture and polarized flux data to separate host galaxy contamination from reflected nuclear light. In support of popular unification models, we find it to be similar to typical type 1 Seyfert galaxy and quasar continua. The bolometric luminosity of the active nucleus is 2.2 x 10(exp 11) (f(sub refl)/0.01)(exp -1)(D/22Mpc)(exp 2) L(sub sun), where f(sub refl) is the fraction of nuclear flux reflected into our line of sight and D is the distance to NGC 1068.

  8. Intrinsic noise in systems with switching environments

    NASA Astrophysics Data System (ADS)

    Hufton, Peter G.; Lin, Yen Ting; Galla, Tobias; McKane, Alan J.

    2016-05-01

    We study individual-based dynamics in finite populations, subject to randomly switching environmental conditions. These are inspired by models in which genes transition between on and off states, regulating underlying protein dynamics. Similarly, switches between environmental states are relevant in bacterial populations and in models of epidemic spread. Existing piecewise-deterministic Markov process approaches focus on the deterministic limit of the population dynamics while retaining the randomness of the switching. Here we go beyond this approximation and explicitly include effects of intrinsic stochasticity at the level of the linear-noise approximation. Specifically, we derive the stationary distributions of a number of model systems, in good agreement with simulations. This improves existing approaches which are limited to the regimes of fast and slow switching.

  9. Intrinsic Frequency and the Single Wave Biopsy

    PubMed Central

    Petrasek, Danny; Pahlevan, Niema M.; Tavallali, Peyman; Rinderknecht, Derek G.; Gharib, Morteza

    2015-01-01

    Insulin resistance is the hallmark of classical type II diabetes. In addition, insulin resistance plays a central role in metabolic syndrome, which astonishingly affects 1 out of 3 adults in North America. The insulin resistance state can precede the manifestation of diabetes and hypertension by years. Insulin resistance is correlated with a low-grade inflammatory condition, thought to be induced by obesity as well as other conditions. Currently, the methods to measure and monitor insulin resistance, such as the homeostatic model assessment and the euglycemic insulin clamp, can be impractical, expensive, and invasive. Abundant evidence exists that relates increased pulse pressure, pulse wave velocity (PWV), and vascular dysfunction with insulin resistance. We introduce a potential method of assessing insulin resistance that relies on a novel signal-processing algorithm, the intrinsic frequency method (IFM). The method requires a single pulse pressure wave, thus the term “ wave biopsy.” PMID:26183600

  10. Unraveling the intrinsic color of chlorophyll.

    PubMed

    Milne, Bruce F; Toker, Yoni; Rubio, Angel; Nielsen, Steen Brøndsted

    2015-02-01

    The exact color of light absorbed by chlorophyll (Chl) pigments, the light-harvesters in photosynthesis, is tuned by the protein microenvironment, but without knowledge of the intrinsic color of Chl it remains unclear how large this effect is. Experimental first absorption energies of Chl a and b isolated in vacuo and tagged with quaternary ammonium cations are reported. The energies are largely insensitive to details of the tag structure, a finding supported by first-principles calculations using time-dependent density functional theory. Absorption is significantly blue-shifted compared to that of Chl-containing proteins (by 30-70 nm). A single red-shifting perturbation, such as axial ligation or the protein medium, is insufficient to account even for the smallest shift; the largest requires pigment-pigment interactions.

  11. Hereditary intrinsic factor deficiency in chaldeans.

    PubMed

    Sturm, Amy C; Baack, Elizabeth C; Armstrong, Michael B; Schiff, Deborah; Zia, Ayesha; Savasan, Sureyya; de la Chapelle, Albert; Tanner, Stephan M

    2013-01-01

    Juvenile vitamin B(12) or cobalamin (Cbl) deficiency is notoriously difficult to explain due to numerous acquired and inherited causes. The consequences of insufficient Cbl are megaloblastic anemia, nutrient malabsorption, and neurological problems. The treatment is straightforward with parenteral Cbl supplementation that resolves most health issues without an urgent need to clarify their cause. Aside from being clinically unsatisfying, failing to elucidate the basis of Cbl deficiency means important information regarding recurrence risk is not available to the individual if the cause is contagious or inherited. Acquired causes have largely disappeared in the Modern World because they were mostly due to parasites or malnutrition. Today, perhaps the most common causes of juvenile Cbl deficiency are Imerslund-Gräsbeck syndrome and inherited intrinsic factor deficiency (IFD). Three genes are involved and genetic testing is complicated and not widely available. We used self-identified ancestry to accelerate and confirm the genetic diagnosis of IFD in three families of Chaldean origin. A founder mutation limited to Chaldeans from Iraq in the intrinsic factor gene GIF was identified as the cause. World events reshape the genetic structure of populations and inherited diseases in many ways. In this case, all the patients were diagnosed in the USA among recent immigrants from a single region. While IFD itself is not restricted to one kind of people, certain mutations are limited in their range but migrations relocate them along with their host population. As a result, self-identified ancestry as a stratifying characteristic should perhaps be considered in diagnostic strategies for rare genetic disorders. PMID:23430489

  12. Diverse precerebellar neurons share similar intrinsic excitability.

    PubMed

    Kolkman, Kristine E; McElvain, Lauren E; du Lac, Sascha

    2011-11-16

    The cerebellum dedicates a majority of the brain's neurons to processing a wide range of sensory, motor, and cognitive signals. Stereotyped circuitry within the cerebellar cortex suggests that similar computations are performed throughout the cerebellum, but little is known about whether diverse precerebellar neurons are specialized for the nature of the information they convey. In vivo recordings indicate that firing responses to sensory or motor stimuli vary dramatically across different precerebellar nuclei, but whether this reflects diverse synaptic inputs or differentially tuned intrinsic excitability has not been determined. We targeted whole-cell patch-clamp recordings to neurons in eight precerebellar nuclei which were retrogradely labeled from different regions of the cerebellum in mice. Intrinsic physiology was compared across neurons in the medial vestibular, external cuneate, lateral reticular, prepositus hypoglossi, supragenual, Roller/intercalatus, reticularis tegmenti pontis, and pontine nuclei. Within the firing domain, precerebellar neurons were remarkably similar. Firing faithfully followed temporally modulated inputs, could be sustained at high rates, and was a linear function of input current over a wide range of inputs and firing rates. Pharmacological analyses revealed common expression of Kv3 currents, which were essential for a wide linear firing range, and of SK (small-conductance calcium-activated potassium) currents, which were essential for a wide linear input range. In contrast, membrane properties below spike threshold varied considerably within and across precerebellar nuclei, as evidenced by variability in postinhibitory rebound firing. Our findings indicate that diverse precerebellar neurons perform similar scaling computations on their inputs but may be differentially tuned to synaptic inhibition. PMID:22090493

  13. Unusual biophysics of intrinsically disordered proteins.

    PubMed

    Uversky, Vladimir N

    2013-05-01

    Research of a past decade and a half leaves no doubt that complete understanding of protein functionality requires close consideration of the fact that many functional proteins do not have well-folded structures. These intrinsically disordered proteins (IDPs) and proteins with intrinsically disordered protein regions (IDPRs) are highly abundant in nature and play a number of crucial roles in a living cell. Their functions, which are typically associated with a wide range of intermolecular interactions where IDPs possess remarkable binding promiscuity, complement functional repertoire of ordered proteins. All this requires a close attention to the peculiarities of biophysics of these proteins. In this review, some key biophysical features of IDPs are covered. In addition to the peculiar sequence characteristics of IDPs these biophysical features include sequential, structural, and spatiotemporal heterogeneity of IDPs; their rough and relatively flat energy landscapes; their ability to undergo both induced folding and induced unfolding; the ability to interact specifically with structurally unrelated partners; the ability to gain different structures at binding to different partners; and the ability to keep essential amount of disorder even in the bound form. IDPs are also characterized by the "turned-out" response to the changes in their environment, where they gain some structure under conditions resulting in denaturation or even unfolding of ordered proteins. It is proposed that the heterogeneous spatiotemporal structure of IDPs/IDPRs can be described as a set of foldons, inducible foldons, semi-foldons, non-foldons, and unfoldons. They may lose their function when folded, and activation of some IDPs is associated with the awaking of the dormant disorder. It is possible that IDPs represent the "edge of chaos" systems which operate in a region between order and complete randomness or chaos, where the complexity is maximal. This article is part of a Special Issue

  14. Universal Usability

    NASA Astrophysics Data System (ADS)

    Horton, Sarah; Leventhal, Laura

    Universal usability of World Wide Web (Web) environments—that is, having 90% of households as successful users—requires universal access, usability, and universal design. Factors such as Web technology and user-centered design contribute to universal access and usability, but key to universal usability is a universal design methodology. Universal design principles for the Web follow from universal design principles for the built environment, and emphasize perceptibility, self-explanation, and tailorability for the user. Universally usable Web environments offer the benefit of expanded participation, as well as the unanticipated benefits that generally follow from innovative design initiatives. However, to achieve Web universal usability, Web designers need tools that facilitate the design of intuitive interfaces without sacrificing universal access.

  15. Intrinsic radioactivity of KSr2I5:Eu2+

    NASA Astrophysics Data System (ADS)

    Rust, M.; Melcher, C.; Lukosi, E.

    2016-10-01

    A current need in nuclear security is an economical, yet high energy resolution (near 2%), scintillation detector suitable for gamma-ray spectroscopy. For current scintillators on the market, there is an inverse relationship between scintillator energy resolution and cost of production. A new promising scintillator, KSr2I5:Eu2+, under development at the University of Tennessee, has achieved an energy resolution of 2.4% at 662 keV at room temperature, with potential growth rates exceeding several millimeters per hour. However, the internal background due to the 40K content could present a hurdle for effective source detection/identification in nuclear security applications. As a first step in addressing this question, this paper reports on a computational investigation of the intrinsic differential pulse height spectrum (DPHS) generated by 40K within the KSr2I5:Eu2+ scintillator as a function of crystal geometry. It was found that the DPHS remains relatively equal to a constant multiplicative factor of the negatron emission spectrum with a direct increase of the 1.46 MeV photopeak relative height to the negatron spectrum with volume. Further, peak pileup does not readily manifest itself for practical KSr2I5:Eu2+ volumes.

  16. Uncovering the intrinsic geometry from the atomic pair distribution function of nanomaterials

    NASA Astrophysics Data System (ADS)

    Lei, Ming; de Graff, Adam M. R.; Thorpe, M. F.; Wells, Stephen A.; Sartbaeva, Asel

    2009-07-01

    Atomic pair distribution functions are useful because they have an easy intuitive interpretation and can be obtained both experimentally and from computer-generated structure models. For bulk materials, atomic pair distribution functions are solely determined by the intrinsic atomic geometry, i.e., how atoms are positioned with respect to one another. For a nanomaterial, however, the atomic pair distribution function also depends on the shape and size of the nanomaterial. A modified form of the radial distribution function is discussed that decouples shape and size effects from intrinsic effects so that nanomaterials of any shape and size, sharing a common atomic geometry, map onto a universal curve, by using a form factor. Mapping onto this universal curve allows differences in the intrinsic atomic geometry of nanomaterials of various shapes and sizes to be directly compared. This approach is demonstrated on nanoscale amorphous and crystalline silica models. It is shown how form factors can be computed for arbitrary shapes and this is illustrated for tetrahedral nanoparticles of vitreous silica.

  17. Status report on the NCSL Intrinsic/Derived Standards Committee

    SciTech Connect

    Pettit, R.B.

    1994-05-01

    The history and present status of the NCSL intrinsic/Derived Standards Committee is presented, including a review of the current published Recommended Intrinsic/Derived Standard Practices (RISPs) and the four Working Groups that are in the process of developing new RISPs. One of the documents under development is a Reference Catalogue that documents important information associated with over forty intrinsic/derived standards. The generic information on each standard in the Catalogue, as well as its Table of contents, are presented.

  18. Separating weak lensing and intrinsic alignments using radio observations

    NASA Astrophysics Data System (ADS)

    Whittaker, Lee; Brown, Michael L.; Battye, Richard A.

    2015-07-01

    We discuss methods for performing weak lensing using radio observations to recover information about the intrinsic structural properties of the source galaxies. Radio surveys provide unique information that can benefit weak lensing studies, such as H I emission, which may be used to construct galaxy velocity maps, and polarized synchrotron radiation; both of which provide information about the unlensed galaxy and can be used to reduce galaxy shape noise and the contribution of intrinsic alignments. Using a proxy for the intrinsic position angle of an observed galaxy, we develop techniques for cleanly separating weak gravitational lensing signals from intrinsic alignment contamination in forthcoming radio surveys. Random errors on the intrinsic orientation estimates introduce biases into the shear and intrinsic alignment estimates. However, we show that these biases can be corrected for if the error distribution is accurately known. We demonstrate our methods using simulations, where we reconstruct the shear and intrinsic alignment auto- and cross-power spectra in three overlapping redshift bins. We find that the intrinsic position angle information can be used to successfully reconstruct both the lensing and intrinsic alignment power spectra with negligible residual bias.

  19. Motivational climate and intrinsic motivation of young basketball players.

    PubMed

    Goudas, M

    1998-02-01

    The present study examined the relationship between motivational climate with intrinsic motivation for athletes with high and low perceived competence. It was predicted that for highly competent athletes a motivational climate of high mastery and high performance would be associated with enhanced intrinsic motivation whereas for athletes of low competence perceptions of a motivational climate of high mastery would be associated with higher intrinsic motivation. Analysis for 100 male basketball players showed that there was no significant interaction between perceived competence and perceptions of motivational climate. Scores for perceptions of a task-involving climate were significantly correlated with intrinsic motivation.

  20. Intrinsic motivation, extrinsic motivation, and learning English as a foreign language.

    PubMed

    Shaikholeslami, Razieh; Khayyer, Mohammad

    2006-12-01

    The objective of this study was to examine the relationships of amotivation, extrinsic motivation, and intrinsic motivation with learning the English language. The 230 Iranian students at Shiraz University were tested using the Language Learning Orientations Scales to measure Amotivation, Extrinsic Motivation, and Intrinsic Motivation as explanatory variables. Grade point average in English exams was selected as a measure of English learning Achievement. Multiple regression analysis revealed that learning Achievement scores were predicted by scores on the Amotivation subscale, Introjected Regulation subscale, Knowledge subscale, and Stimulation subscale, whereas, the External and Identified Regulation and Accomplishment subscales did not have a significant relationship with Achievement. The results are discussed in terms of differences in Iranian context and culture.

  1. Regulation and aggregation of intrinsically disordered peptides.

    PubMed

    Levine, Zachary A; Larini, Luca; LaPointe, Nichole E; Feinstein, Stuart C; Shea, Joan-Emma

    2015-03-01

    Intrinsically disordered proteins (IDPs) are a unique class of proteins that have no stable native structure, a feature that allows them to adopt a wide variety of extended and compact conformations that facilitate a large number of vital physiological functions. One of the most well-known IDPs is the microtubule-associated tau protein, which regulates microtubule growth in the nervous system. However, dysfunctions in tau can lead to tau oligomerization, fibril formation, and neurodegenerative disease, including Alzheimer's disease. Using a combination of simulations and experiments, we explore the role of osmolytes in regulating the conformation and aggregation propensities of the R2/wt peptide, a fragment of tau containing the aggregating paired helical filament (PHF6*). We show that the osmolytes urea and trimethylamine N-oxide (TMAO) shift the population of IDP monomer structures, but that no new conformational ensembles emerge. Although urea halts aggregation, TMAO promotes the formation of compact oligomers (including helical oligomers) through a newly proposed mechanism of redistribution of water around the perimeter of the peptide. We put forth a "superposition of ensembles" hypothesis to rationalize the mechanism by which IDP structure and aggregation is regulated in the cell.

  2. Conformational Recognition of an Intrinsically Disordered Protein

    PubMed Central

    Krieger, James M.; Fusco, Giuliana; Lewitzky, Marc; Simister, Philip C.; Marchant, Jan; Camilloni, Carlo; Feller, Stephan M.; De Simone, Alfonso

    2014-01-01

    There is a growing interest in understanding the properties of intrinsically disordered proteins (IDPs); however, the characterization of these states remains an open challenge. IDPs appear to have functional roles that diverge from those of folded proteins and revolve around their ability to act as hubs for protein-protein interactions. To gain a better understanding of the modes of binding of IDPs, we combined statistical mechanics, calorimetry, and NMR spectroscopy to investigate the recognition and binding of a fragment from the disordered protein Gab2 by the growth factor receptor-bound protein 2 (Grb2), a key interaction for normal cell signaling and cancer development. Structural ensemble refinement by NMR chemical shifts, thermodynamics measurements, and analysis of point mutations indicated that the population of preexisting bound conformations in the free-state ensemble of Gab2 is an essential determinant for recognition and binding by Grb2. A key role was found for transient polyproline II (PPII) structures and extended conformations. Our findings are likely to have very general implications for the biological behavior of IDPs in light of the evidence that a large fraction of these proteins possess a specific propensity to form PPII and to adopt conformations that are more extended than the typical random-coil states. PMID:24739176

  3. Rapid identification of microorganisms by intrinsic fluorescence

    NASA Astrophysics Data System (ADS)

    Bhatta, Hemant; Goldys, Ewa M.; Learmonth, Robert

    2005-03-01

    Microbial contamination has serious consequences for the industries that use fermentation processes. Common contaminants such as faster growing lactic acid bacteria or wild yeast can rapidly outnumber inoculated culture yeast and produce undesirable end products. Our study focuses on a rapid method of identification of such contaminants based on autofluorescence spectroscopy of bacterial and yeast species. Lactic acid bacteria (Lac-tobacillus casei), and yeast (Saccharomyces cerevisiae) were cultured under controlled conditions and studied for variations in their autofluorescence. We observed spectral differences in the spectral range representative of tryptophan residues of proteins, with excitation at 290 nm and emission scanned in the 300 nm - 440 nm range. Excitation scans between 240 nm and 310 nm were also performed for the emission at 340 nm. Moreover, we observed clearly pronounced differences in the excitation and emission in the visible range, with 410 nm excitation. These results demonstrate that bacterial and yeast species can be differentiated using their intrinsic fluorescence both in UV and in the visible region. The comparative spectroscopic study of selected strains of Saccharomyces yeast showed clear differences between strains. Spectrally-resolved laser scanning microscopy was carried out to link the results obtained using ensembles of cells with spectral properties of individual cells. Strongly fluorescent subpopulation were observed for all yeast strains with excitation at 405 nm. The fluorescence spectra showed variations correlated with cell brightness. The presented results demonstrate that using autofluorescence, it is possible to differentiate between yeast and lactic acid bacteria and between different yeast species.

  4. Diffuse intrinsic pontine glioma: poised for progress.

    PubMed

    Warren, Katherine E

    2012-01-01

    Diffuse intrinsic pontine gliomas (DIPGs) are amongst the most challenging tumors to treat. Surgery is not an option, the effects of radiation therapy are temporary, and no chemotherapeutic agent has demonstrated significant efficacy. Numerous clinical trials of new agents and novel therapeutic approaches have been performed over the course of several decades in efforts to improve the outcome of children with DIPG, yet without success. The diagnosis of DIPG is based on radiographic findings in the setting of a typical clinical presentation, and tissue is not routinely obtained as the standard of care. The paradigm for treating children with these tumors has been based on that for supratentorial high-grade gliomas in adults as the biology of these lesions were presumed to be similar. However, recent pivotal studies demonstrate that DIPGs appear to be their own entity. Simply identifying this fact releases a number of constraints and opens opportunities for biologic investigation of these lesions, setting the stage to move forward in identifying DIPG-specific treatments. This review will summarize the current state of knowledge of DIPG, discuss obstacles to therapy, and summarize results of recent biologic studies.

  5. Understanding oceanic migrations with intrinsic biogeochemical markers.

    PubMed

    Ramos, Raül; González-Solís, Jacob; Croxall, John P; Oro, Daniel; Ruiz, Xavier

    2009-01-01

    Migratory marine vertebrates move annually across remote oceanic water masses crossing international borders. Many anthropogenic threats such as overfishing, bycatch, pollution or global warming put millions of marine migrants at risk especially during their long-distance movements. Therefore, precise knowledge about these migratory movements to understand where and when these animals are more exposed to human impacts is vital for addressing marine conservation issues. Because electronic tracking devices suffer from several constraints, mainly logistical and financial, there is emerging interest in finding appropriate intrinsic markers, such as the chemical composition of inert tissues, to study long-distance migrations and identify wintering sites. Here, using tracked pelagic seabirds and some of their own feathers which were known to be grown at different places and times within the annual cycle, we proved the value of biogeochemical analyses of inert tissue as tracers of marine movements and habitat use. Analyses of feathers grown in summer showed that both stable isotope signatures and element concentrations can signal the origin of breeding birds feeding in distinct water masses. However, only stable isotopes signalled water masses used during winter because elements mainly accumulated during the long breeding period are incorporated into feathers grown in both summer and winter. Our findings shed new light on the simple and effective assignment of marine organisms to distinct oceanic areas, providing new opportunities to study unknown migration patterns of secretive species, including in relation to human-induced mortality on specific populations in the marine environment. PMID:19623244

  6. Understanding oceanic migrations with intrinsic biogeochemical markers.

    PubMed

    Ramos, Raül; González-Solís, Jacob; Croxall, John P; Oro, Daniel; Ruiz, Xavier

    2009-07-22

    Migratory marine vertebrates move annually across remote oceanic water masses crossing international borders. Many anthropogenic threats such as overfishing, bycatch, pollution or global warming put millions of marine migrants at risk especially during their long-distance movements. Therefore, precise knowledge about these migratory movements to understand where and when these animals are more exposed to human impacts is vital for addressing marine conservation issues. Because electronic tracking devices suffer from several constraints, mainly logistical and financial, there is emerging interest in finding appropriate intrinsic markers, such as the chemical composition of inert tissues, to study long-distance migrations and identify wintering sites. Here, using tracked pelagic seabirds and some of their own feathers which were known to be grown at different places and times within the annual cycle, we proved the value of biogeochemical analyses of inert tissue as tracers of marine movements and habitat use. Analyses of feathers grown in summer showed that both stable isotope signatures and element concentrations can signal the origin of breeding birds feeding in distinct water masses. However, only stable isotopes signalled water masses used during winter because elements mainly accumulated during the long breeding period are incorporated into feathers grown in both summer and winter. Our findings shed new light on the simple and effective assignment of marine organisms to distinct oceanic areas, providing new opportunities to study unknown migration patterns of secretive species, including in relation to human-induced mortality on specific populations in the marine environment.

  7. Intrinsic dynamics of the regional community.

    PubMed

    Ricklefs, Robert E

    2015-06-01

    Patterns of diversity within large regional biotas express the outcomes of processes, operating on both regional and local scales, that influence evolutionary diversification as well as the distribution and abundance of species. Regional analyses of species distributions suggest that neither ecological sorting of species based on their adaptations to the physical environment, nor interactions between competing species, adequately explain patterns of species richness. Potentially competing species appear to utilise broadly overlapping resources with similar proficiency. Phylogenetic and phylogeographic analyses reveal that species abundances and distributions within regions vary independently of evolutionary relationship. This implies the existence of dynamic, species-specific controls on population growth, as could be applied by specialised pathogens or other antagonists. Here, I argue that the changing balance of coevolved interactions between hosts and their antagonists shapes the distribution and abundance of individual host populations as well as patterns of local species richness. Geographical expansion creates allopatric populations and thereby could promote diversification; contraction ultimately leads to extinction. This taxon-cycle dynamic links regional diversity and distribution to intrinsic biological interactions independently of extrinsic ecological conditions. These hypotheses emphasise the central importance of investigating the impacts of pathogens on species abundance and distribution, and the potential consequences of coevolutionary changes in pathogen-host relationships for species formation and extinction.

  8. Textures of quantum intrinsically localized modes

    NASA Astrophysics Data System (ADS)

    Kanbur, Derya; Riseborough, Peter S.

    2014-10-01

    We have examined the lowest-energy members of the quantized intrinsically localized modes (ILMs) of a generalization of the Fermi-Pasta-Ulam Hamiltonian to three dimensions. The lowest-energy ILMs are similar in form to multiphonon bound states, except that the number of phonons is not conserved. The ILMs can be categorized as having a quasispin of either S =2 or 0, and they have other internal quantum numbers. We find that ILMs can form in three dimensions at zero temperature, but only if the interaction exceeds a minimum value. Furthermore, as the temperature is raised, the magnitude of the minimal interaction required to stabilize the ILM is reduced. When the ILMs first form, they split off from the top of the two-phonon continuum. The S =0 ILMs form for lower values of the interaction than the S =2 ILMs. The ILMs form preferentially for center-of-mass momentum q̲ at the corner of the Brillouin zone. The tendency of ILMs to form at this momentum is traced to a confluence of van Hove singularities in the (noninteracting) two-phonon density of states at the top of the two-phonon continuum. We have examined the ILM many-body wave functions and find that the relative coordinate part of the wave functions has symmetries associated with internal quantum numbers.

  9. Adaptive Responses Limited by Intrinsic Noise

    PubMed Central

    Shankar, Prabhat; Nishikawa, Masatoshi; Shibata, Tatsuo

    2015-01-01

    Sensory systems have mechanisms to respond to the external environment and adapt to them. Such adaptive responses are effective for a wide dynamic range of sensing and perception of temporal change in stimulus. However, noise generated by the adaptation system itself as well as extrinsic noise in sensory inputs may impose a limit on the ability of adaptation systems. The relation between response and noise is well understood for equilibrium systems in the form of fluctuation response relation. However, the relation for nonequilibrium systems, including adaptive systems, are poorly understood. Here, we systematically explore such a relation between response and fluctuation in adaptation systems. We study the two network motifs, incoherent feedforward loops (iFFL) and negative feedback loops (nFBL), that can achieve perfect adaptation. We find that the response magnitude in adaption systems is limited by its intrinsic noise, implying that higher response would have higher noise component as well. Comparing the relation of response and noise in iFFL and nFBL, we show that whereas iFFL exhibits adaptation over a wider parameter range, nFBL offers higher response to noise ratio than iFFL. We also identify the condition that yields the upper limit of response for both network motifs. These results may explain the reason of why nFBL seems to be more abundant in nature for the implementation of adaption systems. PMID:26305221

  10. The intrinsic shape of NGC 3379

    NASA Technical Reports Server (NTRS)

    Statler, Thomas S.

    1994-01-01

    Photometric and kinematic data from the literature are combined with new dynamical models to derive the intrinsic shape of the 'standard' elliptical galaxy NGC 3379. The parameters that are best constrained are the dynamical triaxiality T (essentially the triaxiality of the total mass distribution) and the short-to long axis ratio of the light distribution c(sub L). The inferred shape is given by a Bayesian probability distribution in the (T, c(sub L) plane. Assuming a uniform prior, the most probable shape is oblate with a flattening of c(sub L) = 87. The distribution is strongly non-Gaussian, however, and the expectation values, (T) = .31 (c(sub L) = .75, imply a flatter and more triaxial figure. The 68% highest posterior density region allows more triaxial shapes as long as they are fairly round, or flatter shapes as long as they are nearly oblate. These results are essentially unchanged if the galaxy is assumed to rotate about its short axis, or if it is modeled as an S0 with a negligible-mass disk rather than as an elliptical. The suggestion of Capaccioli et al. (ApJ, 371, 535 (1991)) that NGC 3379 is a rather flat, triaxial S0 galaxy is found to be improbable at the 98% level; this conclusion is largely independent of the bulge-to-disk ratio or the relative rotation speeds of the two components.

  11. Visualization of Turbulence-Generated Intrinsic Rotation

    NASA Astrophysics Data System (ADS)

    Feibush, Eliot; Ethier, Stephane; Wang, Weixing; Tang, William

    2012-10-01

    A new visualization has been developed of the 3D vector field of plasma flow computed by global gyrokinetic simulations using the GTS code. The visualization shows the direction, magnitude, and structure of turbulence-generated intrinsic rotation in a tokamak. Vectors indicate the clockwise and counter-clockwise flows around the torus. Color-coded vectors are drawn at each grid point on the poloidal planes. A color scale was developed to maximize contrast within the most heavily populated range of data while preserving visibility of the global minimum and maximum values. Technical highlights include transferring large amounts of simulation data from NERSC to PPPL using multiple streams, parallel rendering by the VisIt software, and multiple nx client sessions connecting to a persistent server session. Each of the 1,000 time steps is rendered to a high definition image. The images are assembled into an animated movie that is compressed for efficient, high quality playback. A workflow is in place for producing visualizations of new simulations.

  12. Intrinsic structural defects in monolayer molybdenum disulfide

    SciTech Connect

    Zhou, Wu; Idrobo Tapia, Juan C

    2013-01-01

    Monolayer molybdenum disulfide (MoS2) is a two-dimensional direct band gap semiconductor with distinctive mechanical, electronic, optical and chemical properties that can be utilized for novel nanoelectronics and optoelectronics devices. The performance of these electronic devices strongly depends on the quality and defect morphology of the MoS2 layers. Yet, little is known about the atomic structure of defects present in monolayer MoS2 and their influences on the material properties. Here we provide a systematic study of various intrinsic structural defects, including point defects, grain boundaries, and edges, in chemical vapor phase grown monolayer MoS2 via direct atomic resolution imaging, and explore their energy landscape and electronic properties using first-principles calculations. We discover that one-dimensional metallic wires can be created via two different types of 60 grain boundaries consisting of distinct 4-fold ring chains. A new type of edge reconstruction, representing a transition state during growth, was also identified, providing insights into the material growth mechanism. The atomic scale study of structural defects presented here brings new opportunities to tailor the properties of MoS2 via controlled synthesis and defect engineering.

  13. Intrinsic ferromagnetism in hexagonal boron nitride nanosheets

    SciTech Connect

    Si, M. S.; Gao, Daqiang E-mail: xueds@lzu.edu.cn; Yang, Dezheng; Peng, Yong; Zhang, Z. Y.; Xue, Desheng E-mail: xueds@lzu.edu.cn; Liu, Yushen; Deng, Xiaohui; Zhang, G. P.

    2014-05-28

    Understanding the mechanism of ferromagnetism in hexagonal boron nitride nanosheets, which possess only s and p electrons in comparison with normal ferromagnets based on localized d or f electrons, is a current challenge. In this work, we report an experimental finding that the ferromagnetic coupling is an intrinsic property of hexagonal boron nitride nanosheets, which has never been reported before. Moreover, we further confirm it from ab initio calculations. We show that the measured ferromagnetism should be attributed to the localized π states at edges, where the electron-electron interaction plays the role in this ferromagnetic ordering. More importantly, we demonstrate such edge-induced ferromagnetism causes a high Curie temperature well above room temperature. Our systematical work, including experimental measurements and theoretical confirmation, proves that such unusual room temperature ferromagnetism in hexagonal boron nitride nanosheets is edge-dependent, similar to widely reported graphene-based materials. It is believed that this work will open new perspectives for hexagonal boron nitride spintronic devices.

  14. Intrinsic Turbulence Stabilization in a Stellarator

    NASA Astrophysics Data System (ADS)

    Xanthopoulos, P.; Plunk, G. G.; Zocco, A.; Helander, P.

    2016-04-01

    The magnetic surfaces of modern stellarators are characterized by complex, carefully optimized shaping and exhibit locally compressed regions of strong turbulence drive. Massively parallel computer simulations of plasma turbulence reveal, however, that stellarators also possess two intrinsic mechanisms to mitigate the effect of this drive. In the regime where the length scale of the turbulence is very small compared to the equilibrium scale set by the variation of the magnetic field, the strongest fluctuations form narrow bandlike structures on the magnetic surfaces. Thanks to this localization, the average transport through the surface is significantly smaller than that predicted at locations of peak turbulence. This feature results in a numerically observed upshift of the onset of turbulence on the surface towards higher ion temperature gradients as compared with the prediction from the most unstable regions. In a second regime lacking scale separation, the localization is lost and the fluctuations spread out on the magnetic surface. Nonetheless, stabilization persists through the suppression of the large eddies (relative to the equilibrium scale), leading to a reduced stiffness for the heat flux dependence on the ion temperature gradient. These fundamental differences with tokamak turbulence are exemplified for the QUASAR stellarator [G. H. Neilson et al., IEEE Trans. Plasma Sci. 42, 489 (2014)].

  15. Intrinsic and extrinsic measurement for Brownian motion

    NASA Astrophysics Data System (ADS)

    Castro-Villarreal, Pavel

    2014-05-01

    Based upon the Smoluchowski equation on curved manifolds, three physical observables are considered for Brownian displacement, namely geodesic displacement s, Euclidean displacement δR, and projected displacement δR⊥. The Weingarten-Gauss equations are used to calculate the mean-square Euclidean displacements in the short-time regime. Our findings show that from an extrinsic point of view the geometry of the space affects the Brownian motion in such a way that the particle’s diffusion is decelerated, contrasting with the intrinsic point of view where dynamics is controlled by the sign of the Gaussian curvature (Castro-Villarreal, 2010 J. Stat. Mech. P08006). Furthermore, it is possible to give exact formulas for <δR> and <δR2> on spheres and minimal surfaces, which are valid for all values of time. In the latter case, surprisingly, Brownian motion corresponds to the usual diffusion in flat geometries, albeit minimal surfaces have non-zero Gaussian curvature. Finally, the two-dimensional case is emphasized due to its close relation to surface self-diffusion in fluid membranes.

  16. The intrinsic memorability of face photographs.

    PubMed

    Bainbridge, Wilma A; Isola, Phillip; Oliva, Aude

    2013-11-01

    The faces we encounter throughout our lives make different impressions on us: Some are remembered at first glance, while others are forgotten. Previous work has found that the distinctiveness of a face influences its memorability--the degree to which face images are remembered or forgotten. Here, we generalize the concept of face memorability in a large-scale memory study. First, we find that memorability is an intrinsic feature of a face photograph--across observers some faces are consistently more remembered or forgotten than others--indicating that memorability can be used for measuring, predicting, and manipulating subsequent memories. Second, we determine the role that 20 personality, social, and memory-related traits play in face memorability. Whereas we find that certain traits (such as kindness, atypicality, and trustworthiness) contribute to face memorability, they do not suffice to explain the variance in memorability scores, even when accounting for noise and differences in subjective experience. This suggests that memorability itself is a consistent, singular measure of a face that cannot be reduced to a simple combination of personality and social facial attributes. We outline modern neuroscience questions that can be explored through the lens of memorability.

  17. Adolescents' Perceptions of Family Connectedness, Intrinsic Religiosity, and Depressed Mood

    ERIC Educational Resources Information Center

    Houltberg, Benjamin J.; Henry, Carolyn S.; Merten, Michael J.; Robinson, Linda C.

    2011-01-01

    Using a sample of 248 ninth and tenth grade students at public high schools, we examined adolescents' perceptions of family connectedness, intrinsic religiosity, and adolescents' gender in relation to depressed mood and whether intrinsic religiosity and gender moderated the association of aspects of family connectedness to adolescent depressed…

  18. Intrinsic Frames of Reference and Egocentric Viewpoints in Scene Recognition

    ERIC Educational Resources Information Center

    Mou, Weimin; Fan, Yanli; McNamara, Timothy P.; Owen, Charles B.

    2008-01-01

    Three experiments investigated the roles of intrinsic directions of a scene and observer's viewing direction in recognizing the scene. Participants learned the locations of seven objects along an intrinsic direction that was different from their viewing direction and then recognized spatial arrangements of three or six of these objects from…

  19. 30 CFR 27.34 - Test for intrinsic safety.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test for intrinsic safety. 27.34 Section 27.34 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.34 Test for intrinsic...

  20. 30 CFR 27.34 - Test for intrinsic safety.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for intrinsic safety. 27.34 Section 27.34 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.34 Test for intrinsic...

  1. 30 CFR 27.34 - Test for intrinsic safety.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test for intrinsic safety. 27.34 Section 27.34 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.34 Test for intrinsic...

  2. The Intrinsic Value of Nature and Moral Education

    ERIC Educational Resources Information Center

    Helton, William S.; Helton, Nicole D.

    2007-01-01

    Many environmental, humane and character educators try to foster a belief in the intrinsic value of nature and a respect for non-human life among students. Marangudakis argues that Christianity advocates anthropocentrism and opposes belief in the intrinsic value of nature. If Marangudakis is correct, then a goal of many environmental and humane…

  3. Creativity as Mediator for Intrinsic Motivation and Sales Performance

    ERIC Educational Resources Information Center

    Bodla, Mahmood A.; Naeem, Basharat

    2014-01-01

    Substantial theoretical and empirical literature indicates inconsistent performance implications of intrinsic motivation, suggesting the possibility of some explanatory mechanisms. However, little is known about the factors that might explain intrinsic motivation and sales force performance relation, particularly in highly competitive and…

  4. Extrinsic and intrinsic regulation of axon regeneration at a crossroads

    PubMed Central

    Kaplan, Andrew; Ong Tone, Stephan; Fournier, Alyson E.

    2015-01-01

    Repair of the injured spinal cord is a major challenge in medicine. The limited intrinsic regenerative response mounted by adult central nervous system (CNS) neurons is further hampered by astrogliosis, myelin debris and scar tissue that characterize the damaged CNS. Improved axon regeneration and recovery can be elicited by targeting extrinsic factors as well as by boosting neuron-intrinsic growth regulators. Our knowledge of the molecular basis of intrinsic and extrinsic regulators of regeneration has expanded rapidly, resulting in promising new targets to promote repair. Intriguingly certain neuron-intrinsic growth regulators are emerging as promising targets to both stimulate growth and relieve extrinsic inhibition of regeneration. This crossroads between the intrinsic and extrinsic aspects of spinal cord injury is a promising target for effective therapies for this unmet need. PMID:26136657

  5. An algebraic foundation for FORTRAN 90 communication intrinsics

    SciTech Connect

    Stiller, L. |

    1992-09-01

    This paper proposes linear algebra and multilinear algebra as a foundation for the implementation and the understanding of several fundamental parallel communication operations. We will analyze three representative operations: the FORTRAN 90 intrinsic SPREAD, the FORTRAN 90 intrinsic SUM and the parallel prefix operator SCAN. By formulating the operations as linear transformations, we hope to be able to apply linear algebraic techniques to reorder and to factor both these transformations and higher level user functions that call these primitives. Several applications of this technique will be discussed. Perhaps the most surprising was simple code that sped up the SPREAD intrinsic on the CM-200 by a factor of up to 6 and the SUM intrinsic by a factor of up to 20. This speedup had immediate and dramatic impact on many parallel programs. The SUM intrinsic was also sped up on the CM-5.

  6. An algebraic foundation for FORTRAN 90 communication intrinsics

    SciTech Connect

    Stiller, L. Johns Hopkins Univ., Baltimore, MD )

    1992-01-01

    This paper proposes linear algebra and multilinear algebra as a foundation for the implementation and the understanding of several fundamental parallel communication operations. We will analyze three representative operations: the FORTRAN 90 intrinsic SPREAD, the FORTRAN 90 intrinsic SUM and the parallel prefix operator SCAN. By formulating the operations as linear transformations, we hope to be able to apply linear algebraic techniques to reorder and to factor both these transformations and higher level user functions that call these primitives. Several applications of this technique will be discussed. Perhaps the most surprising was simple code that sped up the SPREAD intrinsic on the CM-200 by a factor of up to 6 and the SUM intrinsic by a factor of up to 20. This speedup had immediate and dramatic impact on many parallel programs. The SUM intrinsic was also sped up on the CM-5.

  7. Intrinsically Disordered Regions in Autophagy Proteins

    PubMed Central

    Mei, Yang; Su, Minfei; Soni, Gaurav; Salem, Saeed; Colbert, Christopher L.; Sinha, Sangita C.

    2013-01-01

    Autophagy is an essential eukaryotic pathway required for cellular homeostasis. Numerous key autophagy effectors and regulators have been identified, but the mechanism by which they carry out their function in autophagy is not fully understood. Our rigorous bioinformatic analysis shows that the majority of key human autophagy proteins include intrinsically disordered regions (IDRs), which are sequences lacking stable secondary and tertiary structure; suggesting that IDRs play an important, yet hitherto uninvestigated, role in autophagy. Available crystal structures corroborate the absence of structure in some of these predicted IDRs. Regions of orthologs equivalent to the IDRs predicted in the human autophagy proteins are poorly conserved, indicating that these regions may have diverse functions in different homologs. We also show that IDRs predicted in human proteins contain several regions predicted to facilitate protein-protein interactions, and delineate the network of proteins that interact with each predicted IDR-containing autophagy protein, suggesting that many of these interactions may involve IDRs. Lastly, we experimentally show that a BCL2 homology 3 domain (BH3D), within the key autophagy effector BECN1 is an IDR. This BH3D undergoes a dramatic conformational change from coil to α-helix upon binding to BCL2s, with the C-terminal half of this BH3D constituting a binding motif, which serves to anchor the interaction of the BH3D to BCL2s. The information presented here will help inform future in-depth investigations of the biological role and mechanism of IDRs in autophagy proteins. PMID:24115198

  8. Working memory storage is intrinsically domain specific.

    PubMed

    Fougnie, Daryl; Zughni, Samir; Godwin, Douglass; Marois, René

    2015-02-01

    A longstanding debate in working memory (WM) is whether information is maintained in a central, capacity-limited storage system or whether there are domain-specific stores for different modalities. This question is typically addressed by determining whether concurrent storage of 2 different memory arrays produces interference. Prior studies using this approach have shown at least some cost to maintaining 2 memory arrays that differed in perceptual modalities. However, it is not clear whether these WM costs resulted from competition for a central, capacity-limited store or from other potential sources of dual-task interference, such as task preparation and coordination, overlap in representational content (e.g., object vs. space based), or cognitive strategies (e.g., verbalization, chunking of the stimulus material in a higher order structure). In the present study we assess dual-task costs during the concurrent performance of a visuospatial WM task and an auditory object WM task when such sources of interference are minimized. The results show that performance of these 2 WM tasks are independent from each another, even at high WM load. Only when we introduced a common representational format (spatial information) to both WM tasks did dual-task performance begin to suffer. These results are inconsistent with the notion of a domain-independent storage system, and suggest instead that WM is constrained by multiple domain-specific stores and central executive processes. Evidently, there is nothing intrinsic about the functional architecture of the human mind that prevents it from storing 2 distinct representations in WM, as long as these representations do not overlap in any functional domain.

  9. Universal structures of normal and pathological heart rate variability

    PubMed Central

    Gañán-Calvo, Alfonso M.; Fajardo-López, Juan

    2016-01-01

    The circulatory system of living organisms is an autonomous mechanical system softly tuned with the respiratory system, and both developed by evolution as a response to the complex oxygen demand patterns associated with motion. Circulatory health is rooted in adaptability, which entails an inherent variability. Here, we show that a generalized N-dimensional normalized graph representing heart rate variability reveals two universal arrhythmic patterns as specific signatures of health one reflects cardiac adaptability, and the other the cardiac-respiratory rate tuning. In addition, we identify at least three universal arrhythmic profiles whose presences raise in proportional detriment of the two healthy ones in pathological conditions (myocardial infarction; heart failure; and recovery from sudden death). The presence of the identified universal arrhythmic structures together with the position of the centre of mass of the heart rate variability graph provide a unique quantitative assessment of the health-pathology gradient. PMID:26912108

  10. Universal structures of normal and pathological heart rate variability.

    PubMed

    Gañán-Calvo, Alfonso M; Fajardo-López, Juan

    2016-02-25

    The circulatory system of living organisms is an autonomous mechanical system softly tuned with the respiratory system, and both developed by evolution as a response to the complex oxygen demand patterns associated with motion. Circulatory health is rooted in adaptability, which entails an inherent variability. Here, we show that a generalized N-dimensional normalized graph representing heart rate variability reveals two universal arrhythmic patterns as specific signatures of health one reflects cardiac adaptability, and the other the cardiac-respiratory rate tuning. In addition, we identify at least three universal arrhythmic profiles whose presences raise in proportional detriment of the two healthy ones in pathological conditions (myocardial infarction; heart failure; and recovery from sudden death). The presence of the identified universal arrhythmic structures together with the position of the centre of mass of the heart rate variability graph provide a unique quantitative assessment of the health-pathology gradient.

  11. Universal structures of normal and pathological heart rate variability.

    PubMed

    Gañán-Calvo, Alfonso M; Fajardo-López, Juan

    2016-01-01

    The circulatory system of living organisms is an autonomous mechanical system softly tuned with the respiratory system, and both developed by evolution as a response to the complex oxygen demand patterns associated with motion. Circulatory health is rooted in adaptability, which entails an inherent variability. Here, we show that a generalized N-dimensional normalized graph representing heart rate variability reveals two universal arrhythmic patterns as specific signatures of health one reflects cardiac adaptability, and the other the cardiac-respiratory rate tuning. In addition, we identify at least three universal arrhythmic profiles whose presences raise in proportional detriment of the two healthy ones in pathological conditions (myocardial infarction; heart failure; and recovery from sudden death). The presence of the identified universal arrhythmic structures together with the position of the centre of mass of the heart rate variability graph provide a unique quantitative assessment of the health-pathology gradient. PMID:26912108

  12. The Work Values of First Year Spanish University Students

    ERIC Educational Resources Information Center

    Cortés-Pascual, P. A.; Cano-Escoriaza, J.; Orejudo, S.

    2014-01-01

    This study analyzes the work values of 2,951 first-year university students in Spain enrolled in degree programs within the five major areas of university studies. For our research, participants were asked to respond to a Scale of Work Values in which intrinsic, social, and pragmatic extrinsic values as well as extrinsic values related to…

  13. Automated mapping of the ocean floor using the theory of intrinsic random functions of order k

    USGS Publications Warehouse

    David, M.; Crozel, D.; Robb, James M.

    1986-01-01

    High-quality contour maps can be computer drawn from single track echo-sounding data by combining Universal Kriging and the theory of intrinsic random function of order K (IRFK). These methods interpolate values among the closely spaced points that lie along relatively widely spaced lines. The technique provides a variance which can be contoured as a quantitative measure of map precision. The technique can be used to evaluate alternative survey trackline configurations and data collection intervals, and can be applied to other types of oceanographic data. ?? 1986 D. Reidel Publishing Company.

  14. Major intrinsic proteins in biomimetic membranes.

    PubMed

    Nielsen, Claus Hélix

    2010-01-01

    Biological membranes define the structural and functional boundaries in living cells and their organelles. The integrity of the cell depends on its ability to separate inside from outside and yet at the same time allow massive transport of matter in and out the cell. Nature has elegantly met this challenge by developing membranes in the form of lipid bilayers in which specialized transport proteins are incorporated. This raises the question: is it possible to mimic biological membranes and create a membrane based sensor and/or separation device? In the development of a biomimetic sensor/separation technology, a unique class of membrane transport proteins is especially interesting-the major intrinsic proteins (MIPs). Generally, MIPs conduct water molecules and selected solutes in and out of the cell while preventing the passage of other solutes, a property critical for the conservation of the cells internal pH and salt concentration. Also known as water channels or aquaporins they are highly efficient membrane pore proteins some of which are capable of transporting water at very high rates up to 10(9) molecules per second. Some MIPs transport other small, uncharged solutes, such as glycerol and other permeants such as carbon dioxide, nitric oxide, ammonia, hydrogen peroxide and the metalloids antimonite, arsenite, silicic and boric acid depending on the effective restriction mechanism of the protein. The flux properties of MIPs thus lead to the question ifMIPs can be used in separation devices or as sensor devices based on, e.g., the selective permeation of metalloids. In principle a MIP based membrane sensor/separation device requires the supporting biomimetic matrix to be virtually impermeable to anything but water or the solute in question. In practice, however, a biomimetic support matrix will generally have finite permeabilities to both electrolytes and non-electrolytes. The feasibility of a biomimetic MIP device thus depends on the relative transport

  15. VELOCITY EVOLUTION AND THE INTRINSIC COLOR OF TYPE Ia SUPERNOVAE

    SciTech Connect

    Foley, Ryan J.; Sanders, Nathan E.; Kirshner, Robert P.

    2011-12-01

    To understand how best to use observations of Type Ia supernovae (SNe Ia) to obtain precise and accurate distances, we investigate the relations between spectra of SNe Ia and their intrinsic colors. Using a sample of 1630 optical spectra of 255 SNe, based primarily on data from the CfA Supernova Program, we examine how the velocity evolution and line strengths of Si II {lambda}6355 and Ca II H and K are related to the B - V color at peak brightness. We find that the maximum-light velocity of Si II {lambda}6355 and Ca II H and K and the maximum-light pseudo-equivalent width of Si II {lambda}6355 are correlated with intrinsic color, with intrinsic color having a linear relation with the Si II {lambda}6355 measurements. Ca II H and K does not have a linear relation with intrinsic color, but lower-velocity SNe tend to be intrinsically bluer. Combining the spectroscopic measurements does not improve intrinsic color inference. The intrinsic color scatter is larger for higher-velocity SNe Ia-even after removing a linear trend with velocity-indicating that lower-velocity SNe Ia are more 'standard crayons'. Employing information derived from SN Ia spectra has the potential to improve the measurements of extragalactic distances and the cosmological properties inferred from them.

  16. Velocity Evolution and the Intrinsic Color of Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Foley, Ryan J.; Sanders, Nathan E.; Kirshner, Robert P.

    2011-12-01

    To understand how best to use observations of Type Ia supernovae (SNe Ia) to obtain precise and accurate distances, we investigate the relations between spectra of SNe Ia and their intrinsic colors. Using a sample of 1630 optical spectra of 255 SNe, based primarily on data from the CfA Supernova Program, we examine how the velocity evolution and line strengths of Si II λ6355 and Ca II H&K are related to the B - V color at peak brightness. We find that the maximum-light velocity of Si II λ6355 and Ca II H&K and the maximum-light pseudo-equivalent width of Si II λ6355 are correlated with intrinsic color, with intrinsic color having a linear relation with the Si II λ6355 measurements. Ca II H&K does not have a linear relation with intrinsic color, but lower-velocity SNe tend to be intrinsically bluer. Combining the spectroscopic measurements does not improve intrinsic color inference. The intrinsic color scatter is larger for higher-velocity SNe Ia—even after removing a linear trend with velocity—indicating that lower-velocity SNe Ia are more "standard crayons." Employing information derived from SN Ia spectra has the potential to improve the measurements of extragalactic distances and the cosmological properties inferred from them.

  17. Structure of gamma-ray burst jets: intrinsic versus apparent properties

    NASA Astrophysics Data System (ADS)

    Salafia, O. S.; Ghisellini, G.; Pescalli, A.; Ghirlanda, G.; Nappo, F.

    2015-07-01

    With this paper we introduce the concept of apparent structure of a gamma-ray burst (GRB) jet, as opposed to its intrinsic structure. The latter is customarily defined specifying the functions ɛ(θ) (the energy emitted per jet unit solid angle) and Γ(θ) (the Lorentz factor of the emitting material); the apparent structure is instead defined by us as the isotropic equivalent energy Eiso(θv) as a function of the viewing angle θv. We show how to predict the apparent structure of a jet given its intrinsic structure. We find that a Gaussian intrinsic structure yields a power-law apparent structure: this opens a new viewpoint on the Gaussian (which can be understood as a proxy for a realistic narrow, well-collimated jet structure) as a possible candidate for a quasi-universal GRB jet structure. We show that such a model (a) is consistent with recent constraints on the observed luminosity function of GRBs; (b) implies fewer orphan afterglows with respect to the standard uniform model; (c) can break out the progenitor star (in the collapsar scenario) without wasting an unreasonable amount of energy; (d) is compatible with the explanation of the Amati correlation as a viewing angle effect; (e) can be very standard in energy content, and still yield a very wide range of observed isotropic equivalent energies.

  18. Simple intrinsic defects in GaAs : numerical supplement.

    SciTech Connect

    Schultz, Peter Andrew

    2012-04-01

    This Report presents numerical tables summarizing properties of intrinsic defects in gallium arsenide, GaAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz and O.A. von Lilienfeld, 'Simple intrinsic defects in GaAs', Modelling Simul. Mater. Sci Eng., Vol. 17, 084007 (2009), and intended for use as reference tables for a defect physics package in device models. The numerical results for density functional theory calculations of properties of simple intrinsic defects in gallium arsenide are presented.

  19. Direct probe of the intrinsic charm content of the proton

    NASA Astrophysics Data System (ADS)

    Boettcher, Tom; Ilten, Philip; Williams, Mike

    2016-04-01

    Measurement of Z bosons produced in association with charm jets (Z c ) in proton-proton collisions in the forward region provides a direct probe of a potential nonperturbative (intrinsic) charm component in the proton wave function. We provide a detailed study of the potential to measure Z c production at the LHCb experiment in Runs 2 and 3 of the LHC. The sensitivity to valence-like (sea-like) intrinsic charm is predicted to be ⟨x ⟩IC≳0.3 %(1 %). The impact of intrinsic charm on Higgs production at the LHC, including H c , is also discussed in detail.

  20. Linear magnetization dependence of the intrinsic anomalous Hall effect.

    PubMed

    Zeng, Changgan; Yao, Yugui; Niu, Qian; Weitering, Hanno H

    2006-01-27

    The anomalous Hall effect is investigated experimentally and theoretically for ferromagnetic thin films of Mn5Ge3. We have separated the intrinsic and extrinsic contributions to the experimental anomalous Hall effect and calculated the intrinsic anomalous Hall conductivity from the Berry curvature of the Bloch states using first-principles methods. The intrinsic anomalous Hall conductivity depends linearly on the magnetization, which can be understood from the long-wavelength fluctuations of the spin orientation at finite temperatures. The quantitative agreement between theory and experiment is remarkably good, not only near 0 K but also at finite temperatures, up to about approximately 240 K (0.8TC).

  1. Extrinsic and Intrinsic Contributions to Plasmon Peaks in Solids

    NASA Astrophysics Data System (ADS)

    Alshehabi, Abbas; Kawai, Jun

    2016-01-01

    Intrinsic and extrinsic plasmons are defined and the contribution of each determined. It is shown that quantum interference between intrinsic and extrinsic satellites in X-ray photoelectron spectroscopy (XPS) as well as in Auger electron spectra (AES) does not occur for plasmon loss peaks higher than first order. Line widths in measured reflected electron energy loss spectra (EELS) are analysed by subtracting the Shirley background. Contrary to common understanding, extrinsic and intrinsic contributions by plasmon peaks can be experimentally distinguishable by comparison of line widths.

  2. Baby universes.

    NASA Astrophysics Data System (ADS)

    Strominger, Andrew

    The following sections are included: * INTRODUCTION * TOPOLOGY CHANGE AND THIRD QUANTIZATION IN 0+1 DIMENSIONS * Third Quantization of Free One-dimensional Universes * Third Quantization of Interacting One-Dimensional Universes * The Single-Universe Approximation and Dynamical Determination of Coupling Constants * The Third Quantized Uncertainty Principle * THIRD QUANTIZATION IN 3+1 DIMENSIONS * The Gauge Invariant Action * Relation to Other Formalisms * PARENT AND BABY UNIVERSES * The Hybrid Action * Baby Universe Field Operators and Spacetime Couplings * INSTANTONS-FROM QUANTUM MECHANICS TO QUANTUM GRAVITY * Quantum Mechanics * Quantum Field Theory * Quantum Gravity * Axionic Instantons * The Small Expansion Parameter * THE AXION MODEL AND THE INSTANTON APPROXIMATION * THE COSMOLOGICAL CONSTANT * The Hawking-Baum Argument * Baby Universes and Coleman's Argument * ACKNOWLEDGEMENTS * REFERENCES

  3. A collection of intrinsic disorder characterizations from eukaryotic proteomes

    PubMed Central

    Vincent, Michael; Schnell, Santiago

    2016-01-01

    Intrinsically disordered proteins and protein regions lack a stable three-dimensional structure under physiological conditions. Several proteomic investigations of intrinsic disorder have been performed to date and have found disorder to be prevalent in eukaryotic proteomes. Here we present descriptive statistics of intrinsic disorder features for ten model eukaryotic proteomes that have been calculated from computational disorder prediction algorithms. The data descriptor also provides consensus disorder annotations as well as additional physical parameters relevant to protein disorder, and further provides protein existence information for all proteins included in our analysis. The complete datasets can be downloaded freely, and it is envisaged that they will be updated periodically with new proteomes and protein disorder prediction algorithms. These datasets will be especially useful for assessing protein disorder, and conducting novel analyses that advance our understanding of intrinsic disorder and protein structure. PMID:27326998

  4. Spatial Reasoning With Multiple Intrinsic Frames of Reference

    PubMed Central

    Tamborello, Franklin P; Sun, Yanlong; Wang, Hongbin

    2016-01-01

    Establishing and updating spatial relationships between objects in the environment is vital to maintaining situation awareness and supporting many socio-spatial tasks. In a complex environment, people often need to utilize multiple reference systems that are intrinsic to different objects (intrinsic frame of reference, IFOR), but these IFORs may conflict with each other in one or more ways. Current spatial cognition theories do not adequately address how people handle multi-IFOR reasoning problems. Two experiments manipulated relative orientations of two task-relevant objects with intrinsic axes of orientation as well as their relative task salience. Response times (RTs) decreased with increasing salience of the targeted IFOR. In addition, RTs increased as a consequence of intrinsic orientation conflict, but not by amount of orientation difference. The results suggest that people encounter difficulties when they have to process two conflicting IFOR representations, and that they seem to prioritize processing of each IFOR by salience. PMID:21768066

  5. Exploring the link between intrinsic motivation and quality

    NASA Astrophysics Data System (ADS)

    Christy, Steven M.

    1992-12-01

    This thesis proposes that it is workers' intrinsic motivation that leads them to produce quality work. It reviews two different types of evidence- expert opinion and empirical studies--to attempt to evaluate a link between intrinsic motivation and work quality. The thesis reviews the works of Total Quality writers and behavioral scientists for any connection they might have made between intrinsic motivation and quality. The thesis then looks at the works of Deming and his followers in an attempt to establish a match between Deming's motivational assumptions and the four task rewards in the Thomas/Tymon model of intrinsic motivation: choice, competence, meaningfulness, and progress. Based upon this analysis, it is proposed that the four Thomas/Tymon task rewards are a promising theoretical foundation for explaining the motivational basis of quality for workers in Total Quality organizations.

  6. Intrinsic feature-based pose measurement for imaging motion compensation

    DOEpatents

    Baba, Justin S.; Goddard, Jr., James Samuel

    2014-08-19

    Systems and methods for generating motion corrected tomographic images are provided. A method includes obtaining first images of a region of interest (ROI) to be imaged and associated with a first time, where the first images are associated with different positions and orientations with respect to the ROI. The method also includes defining an active region in the each of the first images and selecting intrinsic features in each of the first images based on the active region. Second, identifying a portion of the intrinsic features temporally and spatially matching intrinsic features in corresponding ones of second images of the ROI associated with a second time prior to the first time and computing three-dimensional (3D) coordinates for the portion of the intrinsic features. Finally, the method includes computing a relative pose for the first images based on the 3D coordinates.

  7. Evidence that intrinsic iron but not intrinsic copper determines S-nitrosocysteine decomposition in buffer solution.

    PubMed

    Vanin, Anatoly F; Muller, Bernard; Alencar, Jacicarlos L; Lobysheva, Irina I; Nepveu, Françoise; Stoclet, Jean-Claude

    2002-11-01

    The present experiments were designed to analyze the influence of copper and iron ions on the process of decomposition of S-nitrosocysteine (cysNO), the most labile species among S-nitrosothiols (RSNO). CysNO fate in buffer solution was evaluated by optical and electron paramagnetic resonance (EPR) spectroscopy, and the consequences on its vasorelaxant effect were studied on noradrenaline-precontracted rat aortic rings. The main results are the following: (i) copper or iron ions, especially in the presence of the reducing agent ascorbate, accelerated the decomposition of cysNO and markedly attenuated the amplitude and duration of the relaxant effect of cysNO; (ii) by contrast, the iron and copper chelators bathophenantroline disulfonic acid (BPDS) and bathocuproine disulfonic acid (BCS) exerted a stabilizing effect on cysNO, prolonged its vasorelaxant effect, and abolished the influence of ascorbate; (iii) in the presence of ascorbate, BPDS displayed a selective inhibitory effect toward the influence of iron ions (but not toward copper ions) on cysNO decomposition and vasorelaxant effect, while BCS prevented the effects of both copper and iron ions; (iv) L-cysteine enhanced stability and prolonged the relaxant effect of cysNO; (v) the process of iron-induced decomposition of cysNO was associated with the formation of EPR-detectable dinitrosyl-iron complexes (DNIC) either with non-thiol- or thiol-containing ligands (depending on the presence of L-cysteine), both of which exhibiting vasorelaxant properties. From these data, it is concluded that the amount of intrinsic copper was probably too low to produce a destabilizing effect even on the most labile RSNO, cysNO, and that only intrinsic iron, through the formation of DNIC, was responsible for the process of cysNO decomposition and thus influenced its vasorelaxant properties. PMID:12381416

  8. Small-number arrays of intrinsic Josephson junctions

    NASA Astrophysics Data System (ADS)

    Yurgens, A.; Torstensson, M.; You, L. X.; Bauch, T.; Winkler, D.; Kakeya, I.; Kadowaki, K.

    2008-04-01

    Arrays of nanometre-thick Bi2212-intrinsic Josephson junctions (IJJ's) are studied in various geometries. The samples with only a few IJJ's allow for the intrinsic-tunnelling spectroscopy with minimum of Joule heating. The reproducible low-voltage peaks of the spectra probably stem from a superconducting gap which is half the usual size. We estimate the internal temperature in the IJJ stacks and analyze the importance of the self-heating for the macroscopic-quantum-tunnelling experiments involving IJJ's.

  9. Self-perception of intrinsic and extrinsic motivation.

    PubMed

    Calder, B J; Staw, B M

    1975-04-01

    Self-perception theory predicts that intrinsic and extrinsic motivation do not combine additively but rather interact. To test this predicted interaction, intrinsic and extrinsic motivation were both manipulated as independent variables. The results revealed a significant interaction for task satisfaction and a trend for the interaction on a behavioral measure. These results are discussed in terms of a general approach to the self-perception of motivation.

  10. Characterization of Intrinsically Disordered Proteins by Analytical Ultracentrifugation.

    PubMed

    Scott, David J; Winzor, Donald J

    2015-01-01

    Intrinsically disordered proteins have traditionally been largely neglected by structural biologists because a lack of rigid structure precludes their study by X-ray crystallography. Structural information must therefore be inferred from physicochemical studies of their solution behavior. Analytical ultracentrifugation yields important information about the gross conformation of an intrinsically disordered protein. Sedimentation velocity studies provide estimates of the weight-average sedimentation and diffusion coefficients of a given macromolecular state of the protein. PMID:26412654

  11. Self-perception of intrinsic and extrinsic motivation.

    PubMed

    Calder, B J; Staw, B M

    1975-04-01

    Self-perception theory predicts that intrinsic and extrinsic motivation do not combine additively but rather interact. To test this predicted interaction, intrinsic and extrinsic motivation were both manipulated as independent variables. The results revealed a significant interaction for task satisfaction and a trend for the interaction on a behavioral measure. These results are discussed in terms of a general approach to the self-perception of motivation. PMID:1159610

  12. Intrinsic honesty and the prevalence of rule violations across societies.

    PubMed

    Gächter, Simon; Schulz, Jonathan F

    2016-03-24

    Deception is common in nature and humans are no exception. Modern societies have created institutions to control cheating, but many situations remain where only intrinsic honesty keeps people from cheating and violating rules. Psychological, sociological and economic theories suggest causal pathways to explain how the prevalence of rule violations in people's social environment, such as corruption, tax evasion or political fraud, can compromise individual intrinsic honesty. Here we present cross-societal experiments from 23 countries around the world that demonstrate a robust link between the prevalence of rule violations and intrinsic honesty. We developed an index of the 'prevalence of rule violations' (PRV) based on country-level data from the year 2003 of corruption, tax evasion and fraudulent politics. We measured intrinsic honesty in an anonymous die-rolling experiment. We conducted the experiments with 2,568 young participants (students) who, due to their young age in 2003, could not have influenced PRV in 2003. We find individual intrinsic honesty is stronger in the subject pools of low PRV countries than those of high PRV countries. The details of lying patterns support psychological theories of honesty. The results are consistent with theories of the cultural co-evolution of institutions and values, and show that weak institutions and cultural legacies that generate rule violations not only have direct adverse economic consequences, but might also impair individual intrinsic honesty that is crucial for the smooth functioning of society. PMID:26958830

  13. Experimental observations of driven and intrinsic rotation in tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Rice, J. E.

    2016-08-01

    Experimental observations of driven and intrinsic rotation in tokamak plasmas are reviewed. For momentum sources, there is direct drive from neutral beam injection, lower hybrid and ion cyclotron range of frequencies waves (including mode conversion flow drive), as well as indirect \\mathbf{j}× \\mathbf{B} forces from fast ion and electron orbit shifts, and toroidal magnetic field ripple loss. Counteracting rotation drive are sinks, such as from neutral drag and toroidal viscosity. Many of these observations are in agreement with the predictions of neo-classical theory while others are not, and some cases of intrinsic rotation remain puzzling. In contrast to particle and heat fluxes which depend on the relevant diffusivity and convection, there is an additional term in the momentum flux, the residual stress, which can act as the momentum source for intrinsic rotation. This term is independent of the velocity or its gradient, and its divergence constitutes an intrinsic torque. The residual stress, which ultimately responds to the underlying turbulence, depends on the confinement regime and is a complicated function of collisionality, plasma shape, and profiles of density, temperature, pressure and current density. This leads to the rich intrinsic rotation phenomenology. Future areas of study include integration of these many effects, advancement of quantitative explanations for intrinsic rotation and development of strategies for velocity profile control.

  14. Intrinsic Honesty and the Prevalence of Rule Violations across Societies

    PubMed Central

    Gächter, Simon; Schulz, Jonathan F.

    2016-01-01

    Deception is common in nature and humans are no exception1. Modern societies have created institutions to control cheating, but many situations remain where only intrinsic honesty keeps people from cheating and violating rules. Psychological2, sociological3 and economic theories4 suggest causal pathways about how the prevalence of rule violations in people's social environment such as corruption, tax evasion, or political fraud can compromise individual intrinsic honesty. Here, we present cross-societal experiments from 23 countries around the world, which demonstrate a robust link between the prevalence of rule violations and intrinsic honesty. We developed an index of the Prevalence of Rule Violations (PRV) based on country-level data of corruption, tax evasion, and fraudulent politics. We measured intrinsic honesty in an anonymous die-rolling experiment.5 We conducted the experiments at least eight years after the measurement of PRV with 2568 young participants (students) who could not influence PRV. We find individual intrinsic honesty is stronger in the subject pools of low PRV countries than those of high PRV countries. The details of lying patterns support psychological theories of honesty.6,7 The results are consistent with theories of the cultural co-evolution of institutions and values8 and show that weak institutions and cultural legacies9-11 that generate rule violations not only have direct adverse economic consequences but might also impair individual intrinsic honesty that is crucial for the smooth functioning of society. PMID:26958830

  15. Intrinsic honesty and the prevalence of rule violations across societies.

    PubMed

    Gächter, Simon; Schulz, Jonathan F

    2016-03-24

    Deception is common in nature and humans are no exception. Modern societies have created institutions to control cheating, but many situations remain where only intrinsic honesty keeps people from cheating and violating rules. Psychological, sociological and economic theories suggest causal pathways to explain how the prevalence of rule violations in people's social environment, such as corruption, tax evasion or political fraud, can compromise individual intrinsic honesty. Here we present cross-societal experiments from 23 countries around the world that demonstrate a robust link between the prevalence of rule violations and intrinsic honesty. We developed an index of the 'prevalence of rule violations' (PRV) based on country-level data from the year 2003 of corruption, tax evasion and fraudulent politics. We measured intrinsic honesty in an anonymous die-rolling experiment. We conducted the experiments with 2,568 young participants (students) who, due to their young age in 2003, could not have influenced PRV in 2003. We find individual intrinsic honesty is stronger in the subject pools of low PRV countries than those of high PRV countries. The details of lying patterns support psychological theories of honesty. The results are consistent with theories of the cultural co-evolution of institutions and values, and show that weak institutions and cultural legacies that generate rule violations not only have direct adverse economic consequences, but might also impair individual intrinsic honesty that is crucial for the smooth functioning of society.

  16. Innovative Universities.

    ERIC Educational Resources Information Center

    Barsi, Louis M.; Kaebnick, Gweneth W.

    1989-01-01

    The phenomenon of innovation within the university is examined, noting the possibility of innovation as a key to college vitality. A study was conducted using a group of institutions that demonstrated recent innovative spirit. Members of the American Association of State Colleges and Universities (AASCU), each has been recognized in an annual…

  17. Challenged Universities.

    ERIC Educational Resources Information Center

    Gillis, Malcolm

    1995-01-01

    Pricing and financial aid issues affecting research universities, particularly private universities, are examined, including underpricing of services, decentralization, and diversification of higher education in the United States. The growth of federal regulation is also considered, especially the State Postsecondary Review Entities (SPREs)…

  18. Universal Expansion.

    ERIC Educational Resources Information Center

    McArdle, Heather K.

    1997-01-01

    Describes a week-long activity for general to honors-level students that addresses Hubble's law and the universal expansion theory. Uses a discrepant event-type activity to lead up to the abstract principles of the universal expansion theory. (JRH)

  19. Overseas Universities.

    ERIC Educational Resources Information Center

    Inter-University Council for Higher Education Overseas, London (England).

    The following articles and reports are presented in this publication of "Overseas Universities:""Appropriate Technology and University Education," by John Twidell; "The Training of Engineering Staff for Higher Education Institutions in Developing Countries," by D. W. Daniel, C. A. Leal, J. H. Maynes and T. Wilmore; "A Case Study of an Academic…

  20. University Futures

    ERIC Educational Resources Information Center

    Smith, Richard

    2012-01-01

    Recent radical changes to university education in England have been discussed largely in terms of the arrangements for transferring funding from the state to the student as consumer, with little discussion of what universities are for. It is important, while challenging the economic rationale for the new system, to resist talking about higher…

  1. University Architecture.

    ERIC Educational Resources Information Center

    Edwards, Brian

    This book explores how universities relate their built environment to academic discourse, asserting that the character of universities is often a charming dialogue between order and disarray. It contains numerous photographs and building plans for example campuses throughout the world. In part 1, "The Campus," chapters are: (1) "Academic Mission…

  2. Our Universe

    NASA Astrophysics Data System (ADS)

    Stern, Alan

    2001-03-01

    The Universe in which we live is unimaginably vast and ancient, with countless star systems, galaxies, and extraordinary phenomena such as black holes, dark matter, and gamma ray bursts. What phenomena remain mysteries, even to seasoned scientists? Our Universe is a fascinating collection of essays by some of the world's foremost astrophysicists. Some are theorists, some computational modelers, some observers, but all offer their insights into the most cutting-edge, difficult, and curious aspects of astrophysics. Compiled, the essays describe more than the latest techniques and findings. Each of the ten contributors offers a more personal perspective on their work, revealing what motivates them and how their careers and lives have been shaped by their desire to understand our universe. S. Alan Stern is Director of the Department of Space Studies at Southwest Research Institute in Boulder, Colorado. He is a planetary scientist and astrophysicist with both observational and theoretical interests. Stern is an avid pilot and a principal investigator in NASA's planetary research program, and he was selected to be a NASA space shuttle mission specialist finalist. He is the author of more than 100 papers and popular articles. His most recent book is Pluto & Charon (Wiley, 1997). Contributors: Dr. John Huchra, Harvard University Dr. Esther Hu, University of Hawaii, Honolulu Dr. John Mather, NASA Goddard Space Flight Center Dr. Nick Gnedin, University of Colorado, Boulder Dr. Doug Richstone, University of Michigan, Ann Arbor Dr. Bohdan Paczynski, Princeton University, NJ Dr. Megan Donahue, Space Telescope Science Institute, Baltimore, MD Dr. Jerry Ostriker, Princeton University, New Jersey G. Bothun, University of Oregon, Eugene

  3. Sport Ability Beliefs, 2 x 2 Achievement Goals, and Intrinsic Motivation: The Moderating Role of Perceived Competence in Sport and Exercise

    ERIC Educational Resources Information Center

    Wang, C. K. John; Liu, Woon Chia; Lochbaum, Marc R.; Stevenson, Sarah J.

    2009-01-01

    We examined whether perceived competence moderated the relationships between implicit theories, 2 x 2 achievement goals, and intrinsic motivation for sports and physical activity. We placed 309 university students into high and moderate perceived competence groups. When perceived competence was high, entity beliefs did not predict the…

  4. Turbulent momentum transport and intrinsic rotation in tokamaks

    NASA Astrophysics Data System (ADS)

    Barnes, Michael

    2012-03-01

    A key physics issue for magnetic confinement fusion is the presence of high levels of turbulent particle and energy transport in magnetized plasmas. This transport is detrimental to fusion because it significantly lowers the plasma density and temperature, both of which must be kept high to increase fusion energy yield. Sheared flows have been shown to strongly reduce this plasma turbulent transport. Many current fusion experiments induce sheared flows by injecting beams of neutral particles, which make the plasma differentially rotate. However, this external momentum injection will be much less effective in the large, dense plasmas that may be required for a fusion reactor. A number of recent fusion experiments have measured significant differential rotation even without external momentum injection. This `intrinsic' rotation is a result of the rearrangement of momentum within the plasma. Since this rotation may determine the extent to which turbulent transport is suppressed, it is critical for the community to understand how momentum transport produces intrinsic rotation profiles. This is challenging, as intrinsic rotation exhibits a complex phenomenology that defies simple empirical scalings or heuristic models. This talk gives a brief overview of the intrinsic rotation phenomenology and elucidates features that any viable model for intrinsic rotation must contain. We propose a fully self-consistent, first-principles model for intrinsic rotation, which is based on an asymptotic expansion in the smallness of the turbulence fluctuation frequency relative to the ion Larmor frequency (known as gyrokinetics). Stringent conditions are placed on this model by a symmetry of the gyrokinetic equations. This model has been implemented in the gyrokinetic turbulence code GS2, from which we present simulation results on turbulent momentum transport. Various physical mechanisms that contribute to the momentum transport are studied to determine their dependences on key plasma

  5. Universe Awareness

    NASA Astrophysics Data System (ADS)

    Sankatsing Nava, Tibisay; Russo, Pedro

    2015-08-01

    Universe Awareness (UNAWE) is an educational programme coordinated by Leiden University that uses the beauty and grandeur of the Universe to encourage young children, particularly those from an underprivileged background, to have an interest in science and technology and foster their sense of global citizenship from the earliest age.UNAWE's twofold vision uses our Universe to inspire and motivate very young children: the excitement of the Universe provides an exciting introduction to science and technology, while the vastness and beauty of the Universe helps broaden the mind and stimulate a sense of global citizenship and tolerance. UNAWE's goals are accomplished through four main activities: the coordination of a global network of more than 1000 astronomers, teachers and educators from more than 60 countries, development of educational resources, teacher training activities and evaluation of educational activities.Between 2011 and 2013, EU-UNAWE, the European branch of UNAWE, was funded by the European Commission to implement a project in 5 EU countries and South Africa. This project has been concluded successfully. Since then, the global project Universe Awareness has continued to grow with an expanding international network, new educational resources and teacher trainings and a planned International Workshop in collaboration with ESA in October 2015, among other activities.

  6. Cosmological information in the intrinsic alignments of luminous red galaxies

    SciTech Connect

    Chisari, Nora Elisa; Dvorkin, Cora E-mail: cdvorkin@ias.edu

    2013-12-01

    The intrinsic alignments of galaxies are usually regarded as a contaminant to weak gravitational lensing observables. The alignment of Luminous Red Galaxies, detected unambiguously in observations from the Sloan Digital Sky Survey, can be reproduced by the linear tidal alignment model of Catelan, Kamionkowski and Blandford (2001) on large scales. In this work, we explore the cosmological information encoded in the intrinsic alignments of red galaxies. We make forecasts for the ability of current and future spectroscopic surveys to constrain local primordial non-Gaussianity and Baryon Acoustic Oscillations (BAO) in the cross-correlation function of intrinsic alignments and the galaxy density field. For the Baryon Oscillation Spectroscopic Survey, we find that the BAO signal in the intrinsic alignments is marginally significant with a signal-to-noise ratio of 1.8 and 2.2 with the current LOWZ and CMASS samples of galaxies, respectively, and increasing to 2.3 and 2.7 once the survey is completed. For the Dark Energy Spectroscopic Instrument and for a spectroscopic survey following the EUCLID redshift selection function, we find signal-to-noise ratios of 12 and 15, respectively. Local type primordial non-Gaussianity, parametrized by f{sub NL} = 10, is only marginally significant in the intrinsic alignments signal with signal-to-noise ratios < 2 for the three surveys considered.

  7. An intrinsic timer specifies distal structures of the vertebrate limb

    PubMed Central

    Saiz-Lopez, Patricia; Chinnaiya, Kavitha; Campa, Victor M.; Delgado, Irene; Ros, Maria A.; Towers, Matthew

    2015-01-01

    How the positional values along the proximo-distal axis (stylopod-zeugopod-autopod) of the limb are specified is intensely debated. Early work suggested that cells intrinsically change their proximo-distal positional values by measuring time. Recently, however, it is suggested that instructive extrinsic signals from the trunk and apical ectodermal ridge specify the stylopod and zeugopod/autopod, respectively. Here, we show that the zeugopod and autopod are specified by an intrinsic timing mechanism. By grafting green fluorescent protein-expressing cells from early to late chick wing buds, we demonstrate that distal mesenchyme cells intrinsically time Hoxa13 expression, cell cycle parameters and the duration of the overlying apical ectodermal ridge. In addition, we reveal that cell affinities intrinsically change in the distal mesenchyme, which we suggest results in a gradient of positional values along the proximo-distal axis. We propose a complete model in which a switch from extrinsic signalling to intrinsic timing patterns the vertebrate limb. PMID:26381580

  8. Intrinsic periodic and aperiodic stochastic resonance in an electrochemical cell

    NASA Astrophysics Data System (ADS)

    Tiwari, Ishant; Phogat, Richa; Parmananda, P.; Ocampo-Espindola, J. L.; Rivera, M.

    2016-08-01

    In this paper we show the interaction of a composite of a periodic or aperiodic signal and intrinsic electrochemical noise with the nonlinear dynamics of an electrochemical cell configured to study the corrosion of iron in an acidic media. The anodic voltage setpoint (V0) in the cell is chosen such that the anodic current (I ) exhibits excitable fixed point behavior in the absence of noise. The subthreshold periodic (aperiodic) signal consists of a train of rectangular pulses with a fixed amplitude and width, separated by regular (irregular) time intervals. The irregular time intervals chosen are of deterministic and stochastic origins. The amplitude of the intrinsic internal noise, regulated by the concentration of chloride ions, is then monotonically increased, and the provoked dynamics are analyzed. The signal to noise ratio and the cross-correlation coefficient versus the chloride ions' concentration curves have a unimodal shape indicating the emergence of an intrinsic periodic or aperiodic stochastic resonance. The abscissa for the maxima of these unimodal curves correspond to the optimum value of intrinsic noise where maximum regularity of the invoked dynamics is observed. In the particular case of the intrinsic periodic stochastic resonance, the scanning electron microscope images for the electrode metal surfaces are shown for certain values of chloride ions' concentrations. These images, qualitatively, corroborate the emergence of order as a result of the interaction between the nonlinear dynamics and the composite signal.

  9. Semisupervised Support Vector Machines With Tangent Space Intrinsic Manifold Regularization.

    PubMed

    Sun, Shiliang; Xie, Xijiong

    2016-09-01

    Semisupervised learning has been an active research topic in machine learning and data mining. One main reason is that labeling examples is expensive and time-consuming, while there are large numbers of unlabeled examples available in many practical problems. So far, Laplacian regularization has been widely used in semisupervised learning. In this paper, we propose a new regularization method called tangent space intrinsic manifold regularization. It is intrinsic to data manifold and favors linear functions on the manifold. Fundamental elements involved in the formulation of the regularization are local tangent space representations, which are estimated by local principal component analysis, and the connections that relate adjacent tangent spaces. Simultaneously, we explore its application to semisupervised classification and propose two new learning algorithms called tangent space intrinsic manifold regularized support vector machines (TiSVMs) and tangent space intrinsic manifold regularized twin SVMs (TiTSVMs). They effectively integrate the tangent space intrinsic manifold regularization consideration. The optimization of TiSVMs can be solved by a standard quadratic programming, while the optimization of TiTSVMs can be solved by a pair of standard quadratic programmings. The experimental results of semisupervised classification problems show the effectiveness of the proposed semisupervised learning algorithms.

  10. Diffuse Intrinsic Pontine Glioma: Time for Cautious Optimism.

    PubMed

    Hennika, Tammy; Becher, Oren J

    2016-10-01

    Diffuse intrinsic pontine glioma is a lethal brain cancer that arises in the pons of children. The median survival for children with diffuse intrinsic pontine glioma is less than 1 year from diagnosis, and no improvement in survival has been realized in more than 30 years. Currently, the standard of care for diffuse intrinsic pontine glioma is focal radiation therapy, which provides only temporary relief. Recent genomic analysis of tumors from biopsies and autopsies, have resulted in the discovery of K27M H3.3/H3.1 mutations in 80% and ACVR1 mutations in 25% of diffuse intrinsic pontine gliomas, providing renewed hope for future success in identifying effective therapies. In addition, as stereotactic tumor biopsies at diagnosis at specialized centers have been demonstrated to be safe, biopsies have now been incorporated into several prospective clinical trials. This article summarizes the epidemiology, clinical presentation, diagnosis, prognosis, molecular genetics, current treatment, and future therapeutic directions for diffuse intrinsic pontine glioma.

  11. Intrinsic periodic and aperiodic stochastic resonance in an electrochemical cell.

    PubMed

    Tiwari, Ishant; Phogat, Richa; Parmananda, P; Ocampo-Espindola, J L; Rivera, M

    2016-08-01

    In this paper we show the interaction of a composite of a periodic or aperiodic signal and intrinsic electrochemical noise with the nonlinear dynamics of an electrochemical cell configured to study the corrosion of iron in an acidic media. The anodic voltage setpoint (V_{0}) in the cell is chosen such that the anodic current (I) exhibits excitable fixed point behavior in the absence of noise. The subthreshold periodic (aperiodic) signal consists of a train of rectangular pulses with a fixed amplitude and width, separated by regular (irregular) time intervals. The irregular time intervals chosen are of deterministic and stochastic origins. The amplitude of the intrinsic internal noise, regulated by the concentration of chloride ions, is then monotonically increased, and the provoked dynamics are analyzed. The signal to noise ratio and the cross-correlation coefficient versus the chloride ions' concentration curves have a unimodal shape indicating the emergence of an intrinsic periodic or aperiodic stochastic resonance. The abscissa for the maxima of these unimodal curves correspond to the optimum value of intrinsic noise where maximum regularity of the invoked dynamics is observed. In the particular case of the intrinsic periodic stochastic resonance, the scanning electron microscope images for the electrode metal surfaces are shown for certain values of chloride ions' concentrations. These images, qualitatively, corroborate the emergence of order as a result of the interaction between the nonlinear dynamics and the composite signal. PMID:27627301

  12. Intrinsic motivation and amotivation in first episode and prolonged psychosis.

    PubMed

    Luther, Lauren; Lysaker, Paul H; Firmin, Ruth L; Breier, Alan; Vohs, Jenifer L

    2015-12-01

    The deleterious functional implications of motivation deficits in psychosis have generated interest in examining dimensions of the construct. However, there remains a paucity of data regarding whether dimensions of motivation differ over the course of psychosis. Therefore, this study examined two motivation dimensions, trait-like intrinsic motivation, and the negative symptom of amotivation, and tested the impact of illness phase on the 1) levels of these dimensions and 2) relationship between these dimensions. Participants with first episode psychosis (FEP; n=40) and prolonged psychosis (n=66) completed clinician-rated measures of intrinsic motivation and amotivation. Analyses revealed that when controlling for group differences in gender and education, the FEP group had significantly more intrinsic motivation and lower amotivation than the prolonged psychosis group. Moreover, intrinsic motivation was negatively correlated with amotivation in both FEP and prolonged psychosis, but the magnitude of the relationship did not statistically differ between groups. These findings suggest that motivation deficits are more severe later in the course of psychosis and that low intrinsic motivation may be partially independent of amotivation in both first episode and prolonged psychosis. Clinically, these results highlight the importance of targeting motivation in early intervention services.

  13. Photovoltaic device comprising compositionally graded intrinsic photoactive layer

    DOEpatents

    Hoffbauer, Mark A; Williamson, Todd L

    2013-04-30

    Photovoltaic devices and methods of making photovoltaic devices comprising at least one compositionally graded photoactive layer, said method comprising providing a substrate; growing onto the substrate a uniform intrinsic photoactive layer having one surface disposed upon the substrate and an opposing second surface, said intrinsic photoactive layer consisting essentially of In.sub.1-xA.sub.xN,; wherein: i. 0.ltoreq.x.ltoreq.1; ii. A is gallium, aluminum, or combinations thereof; and iii. x is at least 0 on one surface of the intrinsic photoactive layer and is compositionally graded throughout the layer to reach a value of 1 or less on the opposing second surface of the layer; wherein said intrinsic photoactive layer is isothermally grown by means of energetic neutral atom beam lithography and epitaxy at a temperature of 600.degree. C. or less using neutral nitrogen atoms having a kinetic energy of from about 1.0 eV to about 5.0 eV, and wherein the intrinsic photoactive layer is grown at a rate of from about 5 nm/min to about 100 nm/min.

  14. Scalability, Timing, and System Design Issues for Intrinsic Evolvable Hardware

    NASA Technical Reports Server (NTRS)

    Hereford, James; Gwaltney, David

    2004-01-01

    In this paper we address several issues pertinent to intrinsic evolvable hardware (EHW). The first issue is scalability; namely, how the design space scales as the programming string for the programmable device gets longer. We develop a model for population size and the number of generations as a function of the programming string length, L, and show that the number of circuit evaluations is an O(L2) process. We compare our model to several successful intrinsic EHW experiments and discuss the many implications of our model. The second issue that we address is the timing of intrinsic EHW experiments. We show that the processing time is a small part of the overall time to derive or evolve a circuit and that major improvements in processor speed alone will have only a minimal impact on improving the scalability of intrinsic EHW. The third issue we consider is the system-level design of intrinsic EHW experiments. We review what other researchers have done to break the scalability barrier and contend that the type of reconfigurable platform and the evolutionary algorithm are tied together and impose limits on each other.

  15. Physics of Intrinsic Rotation in Flux-Driven ITG Turbulence

    SciTech Connect

    Ku, S; Dimond, P H; Dif-Pradalier, G; Kwon, J M; Sarazin, Y; Hahm, T S; Garbet, X; Chang, C S; Latu, G; Yoon, E S; Ghendrih, Ph; Yi, S; Strugarek, A; Solomon, W

    2012-02-23

    Global, heat flux-driven ITG gyrokinetic simulations which manifest the formation of macroscopic, mean toroidal flow profiles with peak thermal Mach number 0.05, are reported. Both a particle-in-cell (XGC1p) and a semi-Lagrangian (GYSELA) approach are utilized without a priori assumptions of scale-separation between turbulence and mean fields. Flux-driven ITG simulations with different edge flow boundary conditions show in both approaches the development of net unidirectional intrinsic rotation in the co-current direction. Intrinsic torque is shown to scale approximately linearly with the inverse scale length of the ion temperature gradient. External momentum input is shown to effectively cancel the intrinsic rotation profile, thus confirming the existence of a local residual stress and intrinsic torque. Fluctuation intensity, intrinsic torque and mean flow are demonstrated to develop inwards from the boundary. The measured correlations between residual stress and two fluctuation spectrum symmetry breakers, namely E x B shear and intensity gradient, are similar. Avalanches of (positive) heat flux, which propagate either outwards or inwards, are correlated with avalanches of (negative) parallel momentum flux, so that outward transport of heat and inward transport of parallel momentum are correlated and mediated by avalanches. The probability distribution functions of the outward heat flux and the inward momentum flux show strong structural similarity

  16. Einstein's Universe.

    ERIC Educational Resources Information Center

    Carlson, Eric; Wald, Robert

    1979-01-01

    Presents a guide to be used by students and teachers in conjunction with a television program about Einstein. Provides general information about special and general relativity, and the universe. Includes questions for discussion after each section and a bibliography. (MA)

  17. Universal Truths.

    ERIC Educational Resources Information Center

    Horgan, John

    1990-01-01

    Described is a symposium of Nobel laureates held in the summer of 1990 to discuss cosmology. Different views on the structure and evolution of the universe are presented. Evidence for different theories of cosmology is discussed. (CW)

  18. Expanding Universe

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    A universe that expands with time. Although the possibility had been raised earlier through theoretical work carried out by Willem de Sitter (1872-1934), Aleksandr Friedmann (1888-1925), and the Abbé Georges Lemaître (1894-1966), that our universe is expanding was first demonstrated observationally in 1929 by Edwin P Hubble (1889-1953), through his measurements of the redshifts in the spectra of ...

  19. Undulant Universe

    SciTech Connect

    Barenboim, Gabriela; Mena, Olga; Quigg, Chris; /Fermilab

    2004-12-01

    If the equation of state for ''dark energy'' varies periodically, the expansion of the Universe may have undergone alternating eras of acceleration and deceleration. We examine a specific form that survives existing observational tests, does not single out the present state of the Universe as exceptional, and suggests a future much like the matter-dominated past: a smooth expansion without a final inflationary epoch.

  20. Intrinsically restless: Unifying science, writing, and the human condition

    NASA Astrophysics Data System (ADS)

    Sissom, Matthew

    The field of physics has always fascinated me, but I never possessed the mathematical skills necessary to extend that interest past the point of curiosity. This thesis was set up to explore how I and other writers, specifically Walt Whitman, use(d) the skills we do have to ask and attempt to answer the same cosmic questions normally reserved for scientists overseeing particle collider experiments. In Tao of Physics, Fritjof Capra attempted to blend the principles of Eastern philosophy with the movements associated with modern physics. In doing so, he offers up a few insights into the human desire to "divide the world into separate objects and events" (117), which I believe, when it comes to fiction, greatly influences the audience's interpretive framework. Capra suggests, "To believe that our abstract concepts of separate `things' and `vents' are realities of nature is an illusion" (117). Humans use this division to cope with our everyday environment, yet it is not a fundamental feature of reality but, rather, an abstraction devised by our discriminating and categorizing intellect. It is a coping mechanism, as Capra refers to it, that pins writers in a corner, encouraging them to forms and styles set by their predecessors to better satisfy the "discriminating and categorizing intellect" of their audience. Writers often struggle to achieve a balance between accurately presenting the human condition that, like Capra's description of subatomic particles as "intrinsically restless" (117), changes based on myriad variables and properly structuring their writing to fit a predetermined model. Whitman, a fan of popular science, drew from the scientific world, using his understanding of the interpretive framework, to better craft his poems' metaphors. In "Song of Myself," Whitman suggests that the celebration of one's own existence cannot be separated from the celebration of the universe, "For every atom belonging to me as good belongs to you" (1-3). Whitman's writing

  1. Fluxons in long and annular intrinsic Josephson junction stacks

    NASA Astrophysics Data System (ADS)

    Clauss, T.; Oehmichen, V.; Mößle, M.; Müller, A.; Weber, A.; Koelle, D.; Kleiner, R.

    2002-12-01

    A promising approach towards a THz oscillator based on intrinsic Josephson junctions in high-temperature superconductors is based on the collective motion of Josephson fluxons, which are predicted to form various configurations ranging from a triangular to a quadratic lattice. Not only for this reason, but certainly also for the sake of basic physics, several experimental and theoretical investigations have been done on the subject of collective fluxon dynamics in stacked intrinsic Josephson junctions. In this paper we will present some experimental results on the fluxon dynamics of long intrinsic Josephson junction stacks made of Bi2Sr2CaCu2O8. The stacks were formed either in an open or in an annular geometry, and clear resonant fluxon modes were observed. Experiments discussed include measurements of current-voltage characteristics in external magnetic fields and in external microwave fields.

  2. Intrinsicality: reconsidering spirituality, meaning(s) and mandates.

    PubMed

    Hammell, K W

    2001-06-01

    Canadian occupational therapists have placed spirituality as the central core of their theoretical Model, depicting inner and outer selves that contradict simultaneous declarations concerning the integration of mind/body/spirit. Even the word spirituality has discrepant meanings and failure to articulate one chosen meaning leads to ambiguity. This paper argues that occupational therapists must agree upon a single definition of spirituality that is congruent with our professional mandate and philosophical perspective; and that prevention of misunderstandings between and amongst clients and other health care professionals demands recourse to our own terminology. It is proposed that intrinsicality be employed to articulate the personal philosophy of meaning with which we interpret our lives. Influenced by environmental context and in homeostatic relationship with the body and mind, intrinsicality constitutes the essence of the self and informs occupational choices based upon personal values and priorities. Acknowledgement of intrinsicality respects the uniqueness of individuals' meanings. PMID:11433917

  3. [Intrinsic ureteral endometriosis: description of a striking instance].

    PubMed

    Antonelli, Alessandro; Finotto, Elena; Zambolin, Tiziano; Fisogni, Simona; Simeone, Claudio

    2015-01-01

    Intrinsic ureteral endometriosis is a very rare condition. A 41 y. o. woman with right hydroureteronephrosis and other aspecific symptoms came to our attention. The CT scan showed an ureteral obstacle causing the hydroureteronephrosis. She underwent ureterorenoscopy with biopsies of the lesion that did not result to be diriment. Suspecting a ureteral neoplasm, the patient then underwent ureteral resection and ureterocystoneostomy, and the extemporary histological examination resulted as endometriosis. The abdominal exploration showed a parametrial and a peritoneal growth - both compatible with the extemporary histological examination - that were also excised. The post-operative course was uneventful. The definitive hystological examination confirmed the perioperatory diagnosis. Intrinsic ureteral endometriosis is confirmed as a rare pathology with an indefinite clinical presentation; its typical presentation, namely cyclic hematuria, seems to be an anecdotal feature. Therefore the diagnostics of intrinsic ureteral endometriosis is still difficult even despite such a striking presentation.

  4. Can Observed Randomness Be Certified to Be Fully Intrinsic?

    NASA Astrophysics Data System (ADS)

    Dhara, Chirag; de la Torre, Gonzalo; Acín, Antonio

    2014-03-01

    In general, any observed random process includes two qualitatively different forms of randomness: apparent randomness, which results both from ignorance or lack of control of degrees of freedom in the system, and intrinsic randomness, which is not ascribable to any such cause. While classical systems only possess the first kind of randomness, quantum systems may exhibit some intrinsic randomness. In this Letter, we provide quantum processes in which all the observed randomness is fully intrinsic. These results are derived under minimal assumptions: the validity of the no-signaling principle and an arbitrary (but not absolute) lack of freedom of choice. Our results prove that quantum predictions cannot be completed already in simple finite scenarios, for instance of three parties performing two dichotomic measurements. Moreover, the observed randomness tends to a perfect random bit when increasing the number of parties, thus, defining an explicit process attaining full randomness amplification.

  5. Chimpanzees and bonobos differ in intrinsic motivation for tool use.

    PubMed

    Koops, Kathelijne; Furuichi, Takeshi; Hashimoto, Chie

    2015-01-01

    Tool use in nonhuman apes can help identify the conditions that drove the extraordinary expansion of hominin technology. Chimpanzees and bonobos are our closest living relatives. Whereas chimpanzees are renowned for their tool use, bonobos use few tools and none in foraging. We investigated whether extrinsic (ecological and social opportunities) or intrinsic (predispositions) differences explain this contrast by comparing chimpanzees at Kalinzu (Uganda) and bonobos at Wamba (DRC). We assessed ecological opportunities based on availability of resources requiring tool use. We examined potential opportunities for social learning in immature apes. Lastly, we investigated predispositions by measuring object manipulation and object play. Extrinsic opportunities did not explain the tool use difference, whereas intrinsic predispositions did. Chimpanzees manipulated and played more with objects than bonobos, despite similar levels of solitary and social play. Selection for increased intrinsic motivation to manipulate objects likely also played an important role in the evolution of hominin tool use. PMID:26079292

  6. Drugs for 'protein clouds': targeting intrinsically disordered transcription factors.

    PubMed

    Dunker, A Keith; Uversky, Vladimir N

    2010-12-01

    Transcription factors (TFs) are very attractive but difficult drug targets. The difficulties come from several directions including the binding promiscuity of TFs and the intrinsically disordered nature of their binding sites, which often resemble 'protein clouds'. For a long time the targeting of proteins without defined structures was considered infeasible. Data have now emerged showing that selective blocking of specific interactions of intrinsically disordered TFs with their protein binding partners is possible. Initial hits have been optimized to increase their specificity and affinity. Several strategies have been elaborated for elucidating the mechanisms of blocking of intrinsic disorder-based protein-protein interactions. However, challenges remain in the field of drug development for 'protein clouds'; such development is still in its earliest stage.

  7. The relation of mothers' controlling vocalizations to children's intrinsic motivation.

    PubMed

    Deci, E L; Driver, R E; Hotchkiss, L; Robbins, R J; Wilson, I M

    1993-04-01

    Twenty-six mother-child dyads played together in a laboratory setting. Play sessions were surreptitiously videotaped (with mothers' permission), and each maternal vocalization was transcribed and coded, first into 1 of 24 categories and then ipso facto into one of three supercategories--namely, controlling, autonomy supportive, and neutral. The degree of mothers' controllingness was calculated as the percentage of vocalizations coded as controlling. This index was correlated with the intrinsic motivation of their 6- or 7-year-old children, as assessed primarily by the free-choice behavioral measure and secondarily by a child self-report measure of interest and liking for the task. Both correlations were significantly negative, thereby suggesting that the robust laboratory findings of a negative relation between controlling contexts and individuals' intrinsic motivation are directly generalizable to the domain of parenting. Results are discussed in terms of the processes that undermine intrinsic motivation and the means through which parental controllingness is communicated.

  8. Linear Magnetization Dependence of the Intrinsic Anomalous Hall Effect

    SciTech Connect

    Zeng, C.; Yao, Y.; Niu, Q.; Weitering, Harm H

    2006-01-01

    The anomalous Hall effect is investigated experimentally and theoretically for ferromagnetic thin films of Mn{sub 5}Ge{sub 3}. We have separated the intrinsic and extrinsic contributions to the experimental anomalous Hall effect and calculated the intrinsic anomalous Hall conductivity from the Berry curvature of the Bloch states using first-principles methods. The intrinsic anomalous Hall conductivity depends linearly on the magnetization, which can be understood from the long-wavelength fluctuations of the spin orientation at finite temperatures. The quantitative agreement between theory and experiment is remarkably good, not only near 0 K but also at finite temperatures, up to about -240 K (0.8T{sub c}).

  9. Chimpanzees and bonobos differ in intrinsic motivation for tool use

    PubMed Central

    Koops, Kathelijne; Furuichi, Takeshi; Hashimoto, Chie

    2015-01-01

    Tool use in nonhuman apes can help identify the conditions that drove the extraordinary expansion of hominin technology. Chimpanzees and bonobos are our closest living relatives. Whereas chimpanzees are renowned for their tool use, bonobos use few tools and none in foraging. We investigated whether extrinsic (ecological and social opportunities) or intrinsic (predispositions) differences explain this contrast by comparing chimpanzees at Kalinzu (Uganda) and bonobos at Wamba (DRC). We assessed ecological opportunities based on availability of resources requiring tool use. We examined potential opportunities for social learning in immature apes. Lastly, we investigated predispositions by measuring object manipulation and object play. Extrinsic opportunities did not explain the tool use difference, whereas intrinsic predispositions did. Chimpanzees manipulated and played more with objects than bonobos, despite similar levels of solitary and social play. Selection for increased intrinsic motivation to manipulate objects likely also played an important role in the evolution of hominin tool use. PMID:26079292

  10. Breast cancer intrinsic subtype classification, clinical use and future trends

    PubMed Central

    Dai, Xiaofeng; Li, Ting; Bai, Zhonghu; Yang, Yankun; Liu, Xiuxia; Zhan, Jinling; Shi, Bozhi

    2015-01-01

    Breast cancer is composed of multiple subtypes with distinct morphologies and clinical implications. The advent of microarrays has led to a new paradigm in deciphering breast cancer heterogeneity, based on which the intrinsic subtyping system using prognostic multigene classifiers was developed. Subtypes identified using different gene panels, though overlap to a great extent, do not completely converge, and the avail of new information and perspectives has led to the emergence of novel subtypes, which complicate our understanding towards breast tumor heterogeneity. This review explores and summarizes the existing intrinsic subtypes, patient clinical features and management, commercial signature panels, as well as various information used for tumor classification. Two trends are pointed out in the end on breast cancer subtyping, i.e., either diverging to more refined groups or converging to the major subtypes. This review improves our understandings towards breast cancer intrinsic classification, current status on clinical application, and future trends. PMID:26693050

  11. Intrinsic spin torque without spin-orbit coupling

    PubMed Central

    Kim, Kyoung-Whan; Lee, Kyung-Jin; Lee, Hyun-Woo; Stiles, M. D.

    2016-01-01

    We derive an intrinsic contribution to the non-adiabatic spin torque for non-uniform magnetic textures. It differs from previously considered contributions in several ways and can be the dominant contribution in some models. It does not depend on the change in occupation of the electron states due to the current flow but rather is due to the perturbation of the electronic states when an electric field is applied. Therefore it should be viewed as electric-field-induced rather than current-induced. Unlike previously reported non-adiabatic spin torques, it does not originate from extrinsic relaxation mechanisms nor spin-orbit coupling. This intrinsic non-adiabatic spin torque is related by a chiral connection to the intrinsic spin-orbit torque that has been calculated from the Berry phase for Rashba systems. PMID:26877628

  12. Extrinsic and intrinsic motivation at 30: Unresolved scientific issues

    PubMed Central

    Reiss, Steven

    2005-01-01

    The undermining effect of extrinsic reward on intrinsic motivation remains unproven. The key unresolved issues are construct invalidity (all four definitions are unproved and two are illogical); measurement unreliability (the free-choice measure requires unreliable, subjective judgments to infer intrinsic motivation); inadequate experimental controls (negative affect and novelty, not cognitive evaluation, may explain “undermining” effects); and biased metareviews (studies with possible floor effects excluded, but those with possible ceiling effects included). Perhaps the greatest error with the undermining theory, however, is that it does not adequately recognize the multifaceted nature of intrinsic motivation (Reiss, 2004a). Advice to limit the use of applied behavior analysis based on “hidden” undermining effects is ideologically inspired and is unsupported by credible scientific evidence. PMID:22478436

  13. Determination of intrinsic spin Hall angle in Pt

    SciTech Connect

    Wang, Yi; Deorani, Praveen; Qiu, Xuepeng; Kwon, Jae Hyun; Yang, Hyunsoo

    2014-10-13

    The spin Hall angle in Pt is evaluated in Pt/NiFe bilayers by spin torque ferromagnetic resonance measurements and is found to increase with increasing the NiFe thickness. To extract the intrinsic spin Hall angle in Pt by estimating the total spin current injected into NiFe from Pt, the NiFe thickness dependent measurements are performed and the spin diffusion in the NiFe layer is taken into account. The intrinsic spin Hall angle of Pt is determined to be 0.068 at room temperature and is found to be almost constant in the temperature range of 13–300 K.

  14. Finding intrinsic rewards by embodied evolution and constrained reinforcement learning.

    PubMed

    Uchibe, Eiji; Doya, Kenji

    2008-12-01

    Understanding the design principle of reward functions is a substantial challenge both in artificial intelligence and neuroscience. Successful acquisition of a task usually requires not only rewards for goals, but also for intermediate states to promote effective exploration. This paper proposes a method for designing 'intrinsic' rewards of autonomous agents by combining constrained policy gradient reinforcement learning and embodied evolution. To validate the method, we use Cyber Rodent robots, in which collision avoidance, recharging from battery packs, and 'mating' by software reproduction are three major 'extrinsic' rewards. We show in hardware experiments that the robots can find appropriate 'intrinsic' rewards for the vision of battery packs and other robots to promote approach behaviors.

  15. Failure to label baboon milk intrinsically with iron

    SciTech Connect

    Figueroa-Colon, R.; Elwell, J.H.; Jackson, E.; Osborne, J.W.; Fomon, S.J. )

    1989-11-01

    The widely held belief that 50% of the iron in human milk is absorbed is based on studies that have used an extrinsic radioactive iron tag. To determine the validity of an extrinsic tag, it is necessary to label the milk intrinsically with one isotope and to compare absorption of this isotope with absorption of another isotope added as the extrinsic tag. We chose the baboon as a model and infused 59Fe intravenously. In each of three attempts we failed to label the milk intrinsically.

  16. Intrinsic versus extrinsic anomalous Hall effect in ferromagnets.

    PubMed

    Onoda, Shigeki; Sugimoto, Naoyuki; Nagaosa, Naoto

    2006-09-22

    A unified theory of the anomalous Hall effect (AHE) is presented for multiband ferromagnetic metals with dilute impurities. In the clean limit, the AHE is mostly due to extrinsic skew scattering. When the Fermi level is located around anticrossing of band dispersions split by spin-orbit interaction, the intrinsic AHE to be calculated ab initio is resonantly enhanced by its nonperturbative nature, revealing the extrinsic-to-intrinsic crossover which occurs when the relaxation rate is comparable to the spin-orbit coupling.

  17. Thermal limit to the intrinsic emittance from metal photocathodes

    SciTech Connect

    Feng, Jun Nasiatka, J.; Wan, Weishi; Karkare, Siddharth; Padmore, Howard A.; Smedley, John

    2015-09-28

    Measurements of the intrinsic emittance and transverse momentum distributions obtained from a metal (antimony thin film) photocathode near and below the photoemission threshold are presented. Measurements show that the intrinsic emittance is limited by the lattice temperature of the cathode as the incident photon energy approaches the photoemission threshold. A theoretical model to calculate the transverse momentum distributions near this photoemission threshold is presented. An excellent match between the experimental measurements and the theoretical calculations is demonstrated. These measurements are relevant to low emittance electron sources for Free Electron Lasers and Ultrafast Electron Diffraction experiments.

  18. Theory of extrinsic and intrinsic heterojunctions in thermal equilibrium

    NASA Technical Reports Server (NTRS)

    Von Ross, O.

    1980-01-01

    A careful analysis of an abrupt heterojunction consisting of two distinct semiconductors either intrinsic or extrinsic is presented. The calculations apply to a one-dimensional, nondegenerate structure. Taking into account all appropriate boundary conditions, it is shown that the intrinsic Fermi level shows a discontinuity at the interface between the two materials which leads to a discontinuity of the valence band edge equal to the difference in the band gap energies of the two materials. The conduction band edge stays continuous however. This result is independent of possible charged interface states and in sharp contrast to the Anderson model. The reasons for this discrepancy are discussed.

  19. Supervised dimension reduction of intrinsically low-dimensional data.

    PubMed

    Vlassis, Nikos; Motomura, Yoichi; Kröse, Ben

    2002-01-01

    High-dimensional data generated by a system with limited degrees of freedom are often constrained in low-dimensional manifolds in the original space. In this article, we investigate dimension-reduction methods for such intrinsically low-dimensional data through linear projections that preserve the manifold structure of the data. For intrinsically one dimensional data, this implies projecting to a curve on the plane with as few intersections as possible. We are proposing a supervised projection pursuit method that can be regarded as an extension of the single-index model for nonparametric regression. We show results from a toy and two robotic applications. PMID:11747538

  20. Intrinsic instability of aberration-corrected electron microscopes.

    PubMed

    Schramm, S M; van der Molen, S J; Tromp, R M

    2012-10-19

    Aberration-corrected microscopes with subatomic resolution will impact broad areas of science and technology. However, the experimentally observed lifetime of the corrected state is just a few minutes. Here we show that the corrected state is intrinsically unstable; the higher its quality, the more unstable it is. Analyzing the contrast transfer function near optimum correction, we define an "instability budget" which allows a rational trade-off between resolution and stability. Unless control systems are developed to overcome these challenges, intrinsic instability poses a fundamental limit to the resolution practically achievable in the electron microscope.

  1. Plasma universe

    NASA Technical Reports Server (NTRS)

    Alfven, H.

    1986-01-01

    Traditionally the views on the cosmic environent have been based on observations in the visual octave of the electromagnetic spectrum, during the last half-century supplemented by infrared and radio observations. Space research has opened the full spectrum. Of special importance are the X-ray-gamma-ray regions, in which a number of unexpected phenomena have been discovered. Radiations in these regions are likely to originate mainly from magnetised cosmic plasmas. Such a medium may also emit synchrotron radiation which is observable in the radio region. If a model of the universe is based on the plasma phenomena mentioned it is found that the plasma universe is drastically different from the traditional visual universe. Information about the plasma universe can also be obtained by extrapolation of laboratory experiments and magnetospheric in situ measurements of plasmas. This approach is possible because it is likely that the basic properties of plasmas are the same everywhere. In order to test the usefulness of the plasma universe model it is applied to cosmogony. Such an approach seems to be rather successful. For example, the complicated structure of the Saturnian C ring can be accounted for. It is possible to reconstruct certain phenomena 4 to 5 billions of years ago with an accuracy of better than 1%.

  2. Changes in Intrinsic Motivation as a Function of Negative Feedback and Threats.

    ERIC Educational Resources Information Center

    Deci, Edward L.; Cascio, Wayne F.

    Recent studies have demonstrated that external rewards can affect intrinsic motivation to perform an activity. Money tends to decrease intrinsic motivation, whereas positive verbal reinforcements tend to increase intrinsic motivation. This paper presents evidence that negative feedback and threats of punishment also decrease intrinsic motivation.…

  3. 46 CFR 111.105-11 - Intrinsically safe systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... system must meet ISA RP 12.6 (incorporated by reference, see 46 CFR 110.10-1), except Appendix A.1. ...-11 (both incorporated by reference; see 46 CFR 110.10-1). (b) Each electric cable of an intrinsically...-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING...

  4. 46 CFR 111.105-11 - Intrinsically safe systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... system must meet ISA RP 12.6 (incorporated by reference, see 46 CFR 110.10-1), except Appendix A.1. ...-11 (both incorporated by reference; see 46 CFR 110.10-1). (b) Each electric cable of an intrinsically...-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING...

  5. 46 CFR 111.105-11 - Intrinsically safe systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... system must meet ISA RP 12.6 (incorporated by reference, see 46 CFR 110.10-1), except Appendix A.1. ...-11 (both incorporated by reference; see 46 CFR 110.10-1). (b) Each electric cable of an intrinsically...-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING...

  6. Dominance dynamics of competition between intrinsic and extrinsic grouping cues.

    PubMed

    Luna, Dolores; Villalba-García, Cristina; Montoro, Pedro R; Hinojosa, José A

    2016-10-01

    In the present study we examined the dominance dynamics of perceptual grouping cues. We used a paradigm in which participants selectively attended to perceptual groups based on several grouping cues in different blocks of trials. In each block, single and competing grouping cues were presented under different exposure durations (50, 150 or 350ms). Using this procedure, intrinsic vs. intrinsic cues (i.e. proximity and shape similarity) were compared in Experiment 1; extrinsic vs. extrinsic cues (i.e. common region and connectedness) in Experiment 2; and intrinsic vs. extrinsic cues (i.e. common region and shape similarity) in Experiment 3. The results showed that in Experiment 1, no dominance of any grouping cue was found: shape similarity and proximity grouping cues showed similar reaction times (RTs) and interference effects. In contrast, in Experiments 2 and 3, common region dominated processing: (i) RTs to common region were shorter than those to connectedness (Exp. 2) or shape similarity (Exp. 3); and (ii) when the grouping cues competed, common region interfered with connectedness (Exp. 2) and shape similarity (Exp. 3) more than vice versa. The results showed that the exposure duration of stimuli only affected the connectedness grouping cue. An important result of our experiments indicates that when two grouping cues compete, both the non-attended intrinsic cue in Experiment 1, and the non-dominant extrinsic cue in Experiments 2 and 3, are still perceived and they are not completely lost.

  7. 30 CFR 27.34 - Test for intrinsic safety.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Assemblies, subassemblies, or components that are designed for intrinsic safety shall be tested by introducing into the circuit(s) thereof a circuit-interrupting device which produces an electric spark from the current in the circuit. The circuit-interrupting device shall be placed in a gallery...

  8. 30 CFR 27.34 - Test for intrinsic safety.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... Assemblies, subassemblies, or components that are designed for intrinsic safety shall be tested by introducing into the circuit(s) thereof a circuit-interrupting device which produces an electric spark from the current in the circuit. The circuit-interrupting device shall be placed in a gallery...

  9. Intrinsic Hysteresis Loops Calculation of BZT Thin Films

    NASA Astrophysics Data System (ADS)

    Hikam, M.; Adnan, S. R.

    2014-04-01

    The Landau Devonshire (LK) simulation is utilized to calculate the intrinsic hysteresis properties of Barium Zirconium Titanate (BZT) doped by Indium and Lanthanum. A Delphi program run on Windows platform is used to facilitate the calculation. The simulation is very useful to calculate and understand the Gibbs free energy and the relationship between spontaneous polarization and electric field.

  10. The restless brain: how intrinsic activity organizes brain function

    PubMed Central

    Raichle, Marcus E.

    2015-01-01

    Traditionally studies of brain function have focused on task-evoked responses. By their very nature such experiments tacitly encourage a reflexive view of brain function. While such an approach has been remarkably productive at all levels of neuroscience, it ignores the alternative possibility that brain functions are mainly intrinsic and ongoing, involving information processing for interpreting, responding to and predicting environmental demands. I suggest that the latter view best captures the essence of brain function, a position that accords well with the allocation of the brain's energy resources, its limited access to sensory information and a dynamic, intrinsic functional organization. The nature of this intrinsic activity, which exhibits a surprising level of organization with dimensions of both space and time, is revealed in the ongoing activity of the brain and its metabolism. As we look to the future, understanding the nature of this intrinsic activity will require integrating knowledge from cognitive and systems neuroscience with cellular and molecular neuroscience where ion channels, receptors, components of signal transduction and metabolic pathways are all in a constant state of flux. The reward for doing so will be a much better understanding of human behaviour in health and disease. PMID:25823869

  11. Trapped Electron Mode Turbulence Driven Intrinsic Rotation in Tokamak Plasmas

    SciTech Connect

    Wang, W. X.; Hahm, T. S.; Ethier, S.; Zakharov, L. E.

    2011-02-07

    Recent progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal plasmas is reported with emphasis on electron thermal transport dominated regimes. The turbulence driven intrinsic torque associated with nonlinear residual stress generation by the fluctuation intensity and the intensity gradient in the presence of zonal flow shear induced asymmetry in the parallel wavenumber spectrum is shown to scale close to linearly with plasma gradients and the inverse of the plasma current. These results qualitatively reproduce empirical scalings of intrinsic rotation observed in various experiments. The origin of current scaling is found to be due to enhanced kll symmetry breaking induced by the increased radial variation of the safety factor as the current decreases. The physics origin for the linear dependence of intrinsic torque on pressure gradient is that both turbulence intensity and the zonal flow shear, which are two key ingredients for driving residual stress, increase with the strength of turbulence drive, which is R0/LTe and R0/Lne for the trapped electron mode. __________________________________________________

  12. A Study of Extrinsic vs. Intrinsic Motivation in College Students.

    ERIC Educational Resources Information Center

    Elbel, Jacquelyn; Horton, Irene P.

    Attribution theorists have argued that if an intrinsically motivated activity is extrinsically reinforced, the activity will be devalued and extinguished when the reward is removed. Hypothesizing that activities performed for their instrumental outcome are valued less than activities not so externally oriented, and that activities performed for…

  13. Resolving a Teacher-Student Conflict: An Intrinsic Case Study

    ERIC Educational Resources Information Center

    Isaacson, Atara

    2016-01-01

    This article presents an episode that occurred during a semester-long academic course called: Conduct Problems and Class Navigation. It focuses on investigating the behavior of a student who, because of her uniqueness, was an interesting candidate for an intrinsic case study. This paper presents a distinctive way of handling an interfering and…

  14. Dynamics of intrinsic axial flows in unsheared, uniform magnetic fields

    NASA Astrophysics Data System (ADS)

    Li, J. C.; Diamond, P. H.; Xu, X. Q.; Tynan, G. R.

    2016-05-01

    A simple model for the generation and amplification of intrinsic axial flow in a linear device, controlled shear decorrelation experiment, is proposed. This model proposes and builds upon a novel dynamical symmetry breaking mechanism, using a simple theory of drift wave turbulence in the presence of axial flow shear. This mechanism does not require complex magnetic field structure, such as shear, and thus is also applicable to intrinsic rotation generation in tokamaks at weak or zero magnetic shear, as well as to linear devices. This mechanism is essentially the self-amplification of the mean axial flow profile, i.e., a modulational instability. Hence, the flow development is a form of negative viscosity phenomenon. Unlike conventional mechanisms where the residual stress produces an intrinsic torque, in this dynamical symmetry breaking scheme, the residual stress induces a negative increment to the ambient turbulent viscosity. The axial flow shear is then amplified by this negative viscosity increment. The resulting mean axial flow profile is calculated and discussed by analogy with the problem of turbulent pipe flow. For tokamaks, the negative viscosity is not needed to generate intrinsic rotation. However, toroidal rotation profile gradient is enhanced by the negative increment in turbulent viscosity.

  15. Learning-by-Teaching: Designing Teachable Agents with Intrinsic Motivation

    ERIC Educational Resources Information Center

    Zhao, Guopeng; Ailiya; Shen, Zhiqi

    2012-01-01

    Teachable agent is a type of pedagogical agent which instantiates Learning-by-Teaching theory through simulating a "naive" learner in order to motivate students to teach it. This paper discusses the limitation of existing teachable agents and incorporates intrinsic motivation to the agent model to enable teachable agents with initiative behaviors…

  16. The intrinsic value of visual information affects saccade velocities.

    PubMed

    Xu-Wilson, Minnan; Zee, David S; Shadmehr, Reza

    2009-07-01

    Let us assume that the purpose of any movement is to position our body in a more advantageous or rewarding state. For example, we might make a saccade to foveate an image because our brain assigns an intrinsic value to the information that it expects to acquire at the endpoint of that saccade. Different images might have different intrinsic values. Optimal control theory predicts that the intrinsic value that the brain assigns to targets of saccades should be reflected in the trajectory of the saccade. That is, in anticipation of foveating a highly valued image, our brain should produce a saccade with a higher velocity and shorter duration. Here, we considered four types of images: faces, objects, inverted faces, and meaningless visual noise. Indeed, we found that reflexive saccades that were made to a laser light in anticipation of viewing an image of a face had the highest velocities and shortest durations. The intrinsic value of visual information appears to have a small but significant influence on the motor commands that guide saccades.

  17. Attention and intrinsic rewards in the control of psychophysiologic states.

    PubMed

    Holcomb, J H

    Attention is a process which regulates the information obtained from a stimulus. In this paper I view selective attention as a means of arriving at different psychophysiologic states. Special consideration is given to the self-regulation of enjoyment by selective attention to intrinsically rewarding activities.

  18. Improving Secondary School Students' Achievement using Intrinsic Motivation

    ERIC Educational Resources Information Center

    Albrecht, Erik; Haapanen, Rebecca; Hall, Erin; Mantonya, Michelle

    2009-01-01

    This report describes a program for increasing students' intrinsic motivation in an effort to increase academic achievement. The targeted population consisted of secondary level students in a middle to upper-middle class suburban area. The students of the targeted secondary level classes appeared to be disengaged from learning due to a lack of…

  19. Fostering Reading through Intrinsic Motivation: An Action Research Study.

    ERIC Educational Resources Information Center

    Joyce, Marilyn Z.

    2003-01-01

    Discusses a two-year action research study conducted at a high school that transformed reluctant students into lifelong readers by emphasizing intrinsic motivation as opposed to programs that use rewards to motivate students to read. Explains how to design an action research question. (LRW)

  20. Element Interactivity and Intrinsic, Extraneous, and Germane Cognitive Load

    ERIC Educational Resources Information Center

    Sweller, John

    2010-01-01

    In cognitive load theory, element interactivity has been used as the basic, defining mechanism of intrinsic cognitive load for many years. In this article, it is suggested that element interactivity underlies extraneous cognitive load as well. By defining extraneous cognitive load in terms of element interactivity, a distinct relation between…

  1. Determining the induced and intrinsic fields of Titan

    NASA Astrophysics Data System (ADS)

    Wei, H.; Ma, Y.; Russell, C. T.; Dougherty, M. K.

    2014-12-01

    Cassini mission has obtained abundant measurements around Titan and along its orbit, allowing us to better understand Titan's plasma interaction with its environment and estimate the induced and intrinsic fields from Titan's interior. The magnetic state of Titan could provide important constraints on its interior structures. The presence of an induced field indicates that there are conductive layer/layers in the interior, while the presence and strength of a dynamo-driven intrinsic field provide information on the dynamics in the interior and the thermal state of the material deep inside. When estimating the induced and intrinsic fields of Titan, the most important technique and biggest difficulty is to separate the field generated by the interaction between Titan's ionosphere and its plasma environment from that generated from Titan's interior. Therefore we use MHD simulations to predict the fields from external and internal sources. By comparing observations with simulations, we can search for the signatures of the induced field of Titan and improve the accuracy of our previous intrinsic field estimates.

  2. Effects of Formative Feedback on Intrinsic Motivation: Examining Ethnic Differences

    ERIC Educational Resources Information Center

    El, Ron Pat; Tillema, Harm; van Koppen, Sabine W. M.

    2012-01-01

    In this study we investigate the influence of ethnic differences on student motivation when learning from formative feedback. Interpersonal teacher behavior and student motivational needs are used to explain the effects of assessment for learning on intrinsic motivation by comparing students from different ethnic backgrounds. The final study's…

  3. The restless brain: how intrinsic activity organizes brain function.

    PubMed

    Raichle, Marcus E

    2015-05-19

    Traditionally studies of brain function have focused on task-evoked responses. By their very nature such experiments tacitly encourage a reflexive view of brain function. While such an approach has been remarkably productive at all levels of neuroscience, it ignores the alternative possibility that brain functions are mainly intrinsic and ongoing, involving information processing for interpreting, responding to and predicting environmental demands. I suggest that the latter view best captures the essence of brain function, a position that accords well with the allocation of the brain's energy resources, its limited access to sensory information and a dynamic, intrinsic functional organization. The nature of this intrinsic activity, which exhibits a surprising level of organization with dimensions of both space and time, is revealed in the ongoing activity of the brain and its metabolism. As we look to the future, understanding the nature of this intrinsic activity will require integrating knowledge from cognitive and systems neuroscience with cellular and molecular neuroscience where ion channels, receptors, components of signal transduction and metabolic pathways are all in a constant state of flux. The reward for doing so will be a much better understanding of human behaviour in health and disease.

  4. Ethnic Stigma, Academic Anxiety, and Intrinsic Motivation in Middle Childhood

    ERIC Educational Resources Information Center

    Gillen-O'Neel, Cari; Ruble, Diane N.; Fuligni, Andrew J.

    2011-01-01

    Previous research addressing the dynamics of stigma and academics has focused on African American adolescents and adults. The present study examined stigma awareness, academic anxiety, and intrinsic motivation among 451 young (ages 6-11) and diverse (African American, Chinese, Dominican, Russian, and European American) students. Results indicated…

  5. Intrinsic bond strength of metal films on polymer substrates

    NASA Technical Reports Server (NTRS)

    Wheeler, Donald R.; Osaki, Hiroyuki

    1990-01-01

    A semiquantitative method for the measurement of the intrinsic bond strength between elastic substrates and elastic films that fail by brittle fracture is described. Measurements on a polyethylene terephthalate (PET)-Ni couple were used to verify the essential features of the analysis. It was found that the interfacial shear strength of Ni on PET doubled after ion etching.

  6. Does the human odometer use an extrinsic or intrinsic metric?

    PubMed

    Chrastil, Elizabeth R; Warren, William H

    2014-01-01

    It is commonly assumed that path integration is based on an extrinsic measure of the objective distance traversed during locomotion. In contrast, biological odometers may rely on embodied intrinsic measures, such as idiothetic information specific to an action mode. We investigated this question using a distance reproduction task in which participants traveled an outbound distance and then reproduced that distance using the same or a different action mode. The extrinsic model predicted that distance reproduction should be invariant across action modes, whereas the intrinsic model predicted invariance only within an action mode. In Experiment 1, we held the outbound mode constant while varying the response mode (walk-walk, walk-throw) and corrected for response production error (view-walk, view-throw). In Experiment 2, we crossed different gaits in the outbound and response modes (walk, gallop). In both cases, we found that distance reproduction was significantly more accurate when the outbound and response modes matched, consistent with the intrinsic model. The results indicate that the human odometer preferentially relies on an intrinsic, rather than an extrinsic, metric. This solution is sufficient to support successful path integration within an action mode (but not across action modes), without the difficulties of objective distance estimation. PMID:24197502

  7. Dynamic DNA methylation regulates neuronal intrinsic membrane excitability.

    PubMed

    Meadows, Jarrod P; Guzman-Karlsson, Mikael C; Phillips, Scott; Brown, Jordan A; Strange, Sarah K; Sweatt, J David; Hablitz, John J

    2016-01-01

    Epigenetic modifications, such as DNA cytosine methylation, contribute to the mechanisms underlying learning and memory by coordinating adaptive gene expression and neuronal plasticity. Transcription-dependent plasticity regulated by DNA methylation includes synaptic plasticity and homeostatic synaptic scaling. Memory-related plasticity also includes alterations in intrinsic membrane excitability mediated by changes in the abundance or activity of ion channels in the plasma membrane, which sets the threshold for action potential generation. We found that prolonged inhibition of DNA methyltransferase (DNMT) activity increased intrinsic membrane excitability of cultured cortical pyramidal neurons. Knockdown of the cytosine demethylase TET1 or inhibition of RNA polymerase blocked the increased membrane excitability caused by DNMT inhibition, suggesting that this effect was mediated by subsequent cytosine demethylation and de novo transcription. Prolonged DNMT inhibition blunted the medium component of the after-hyperpolarization potential, an effect that would increase neuronal excitability, and was associated with reduced expression of the genes encoding small-conductance Ca(2+)-activated K(+) (SK) channels. Furthermore, the specific SK channel blocker apamin increased neuronal excitability but was ineffective after DNMT inhibition. Our results suggested that DNMT inhibition enables transcriptional changes that culminate in decreased expression of SK channel-encoding genes and decreased activity of SK channels, thus providing a mechanism for the regulation of neuronal intrinsic membrane excitability by dynamic DNA cytosine methylation. This study has implications for human neurological and psychiatric diseases associated with dysregulated intrinsic excitability. PMID:27555660

  8. The Effects of Extrinsic Reinforcement on Intrinsic Motivation.

    ERIC Educational Resources Information Center

    Blocker, Richard A.; Edwards, R. P.

    1982-01-01

    Discusses the role of extrinsic reinforcement in intrinsic motivation in cognitive attribution theory. Concludes that cognitive attribution theory lacks parsimony, in that extant reinforcement analysis can account for undermining with equal facility. Suggests undermining is of little significance due to its elusive and transient impact on operant…

  9. An Overview of Student Teachers' Academic Intrinsic Motivation

    ERIC Educational Resources Information Center

    Uyulgan, Melis Arzu; Akkuzu, Nalan

    2014-01-01

    Student teachers' desire to learn is affected by a variety of motivational factors. In this study, the effect of some internal and external variables on Academic Intrinsic Motivation (AIM) was explored. First, the validity and reliability of the scale of AIM was determined, then the effect on AIM of variables such as grade levels, academic…

  10. Playwriting Pedagogy and the Myth of Intrinsic Creativity

    ERIC Educational Resources Information Center

    Gardiner, Paul

    2016-01-01

    Debates surrounding the teaching of playwriting are heavily influenced by theories of creativity. This article reports on research in Australian secondary schools that explored the student and teacher experiences of playwriting pedagogy. The findings of the research revealed that teaching was based on a belief in intrinsic creativity: that…

  11. Intrinsic Religion and Internalized Homophobia in Sexual-Minority Youth.

    ERIC Educational Resources Information Center

    Ream, Geoffrey L.

    This research investigates the development of conflict between sexual minority identity and religious identity in sexual minority youth, examining religion as both a risk factor and a protective factor. Intrinsic religion was expected to predict self reported conflict between religious and sexual minority identity. Retrospectively reported…

  12. From mechanical folding trajectories to intrinsic energy landscapes of biopolymers

    PubMed Central

    Hinczewski, Michael; Gebhardt, J. Christof M.; Rief, Matthias; Thirumalai, D.

    2013-01-01

    In single-molecule laser optical tweezer (LOT) pulling experiments, a protein or RNA is juxtaposed between DNA handles that are attached to beads in optical traps. The LOT generates folding trajectories under force in terms of time-dependent changes in the distance between the beads. How to construct the full intrinsic folding landscape (without the handles and beads) from the measured time series is a major unsolved problem. By using rigorous theoretical methods—which account for fluctuations of the DNA handles, rotation of the optical beads, variations in applied tension due to finite trap stiffness, as well as environmental noise and limited bandwidth of the apparatus—we provide a tractable method to derive intrinsic free-energy profiles. We validate the method by showing that the exactly calculable intrinsic free-energy profile for a generalized Rouse model, which mimics the two-state behavior in nucleic acid hairpins, can be accurately extracted from simulated time series in a LOT setup regardless of the stiffness of the handles. We next apply the approach to trajectories from coarse-grained LOT molecular simulations of a coiled-coil protein based on the GCN4 leucine zipper and obtain a free-energy landscape that is in quantitative agreement with simulations performed without the beads and handles. Finally, we extract the intrinsic free-energy landscape from experimental LOT measurements for the leucine zipper. PMID:23487746

  13. Transport of Intrinsic Plutonium Colloids in Saturated Porous Media

    NASA Astrophysics Data System (ADS)

    Zhou, D.; Abdel-Fattah, A.; Boukhalfa, H.; Ware, S. D.; Tarimala, S.; Keller, A. A.

    2011-12-01

    Actinide contaminants were introduced to the subsurface environment as a result of nuclear weapons development and testing, as well as for nuclear power generation and related research activities for defense and civilian applications. Even though most actinide species were believed to be fairly immobile once in the subsurface, recent studies have shown the transport of actinides kilometers away from their disposal sites. For example, the treated liquid wastes released into Mortandad Canyon at the Los Alamos National Laboratory were predicted to travel less than a few meters; however, plutonium and americium have been detected 3.4 km away from the waste outfall. A colloid-facilitated mechanism has been suggested to account for this unexpected transport of these radioactive wastes. Clays, oxides, organic matters, and actinide hydroxides have all been proposed as the possible mobile phase. Pu ions associated with natural colloids are often referred to as pseudo-Pu colloids, in contrast with the intrinsic Pu colloids that consist of Pu oxides. Significant efforts have been made to investigate the role of pseudo-Pu colloids, while few studies have evaluated the environmental behavior of the intrinsic Pu colloids. Given the fact that Pu (IV) has extremely low solubility product constant, it can be inferred that the transport of Pu in the intrinsic form is highly likely at suitable environmental conditions. This study investigates the transport of intrinsic Pu colloids in a saturated alluvium material packed in a cylindrical column (2.5-cm Dia. x 30-cm high) and compares the results to previous data on the transport of pseudo Pu colloids in the same material. A procedure to prepare a stable intrinsic Pu colloid suspension that produced consistent and reproducible electrokinetic and stability data was developed. Electrokinetic properties and aggregation stability were characterized. The Pu colloids, together with trillium as a conservative tracer, were injected into the

  14. A Custom Made Intrinsic Silicone Shade Guide for Indian Population

    PubMed Central

    Behanam, Mohammed; Ahila, S.C.; Jei, J. Brintha

    2016-01-01

    Introduction Replication of natural skin colour in maxillofacial prosthesis has been traditionally done using trial and error method, as concrete shade guides are unavailable till date. Hence a novel custom made intrinsic silicone shade guide has been attempted for Indian population. Aim Reconstruction of maxillofacial defects is challenging, as achieving an aesthetic result is not always easy. A concoction of a novel intrinsic silicone shade guide was contemplated for the study and its reproducibility in clinical practice was analysed. Materials and Methods Medical grade room temperature vulcanising silicone was used for the fabrication of shade tabs. The shade guide consisted of three main groups I, II and III which were divided based upon the hues yellow, red and blue respectively. Five distinct intrinsic pigments were added in definite proportions to subdivide each group of different values from lighter to darker shades. A total number of 15 circular shade tabs comprised the guide. To validate the usage of the guide, visual assessment of colour matching was done by four investigators to investigate the consent of perfect colour correspondence. Data was statistically analysed using kappa coefficients. Results The kappa values were found to be 0.47 to 0.78 for yellow based group I, 0.13 to 0.65 for red based group II, and 0.07 to 0.36 for blue based group III. This revealed that the shade tabs of yellow and red based hues matched well and showed a statistically good colour matching. Conclusion This intrinsic silicone shade guide can be effectively utilised for fabrication of maxillofacial prosthesis with silicone in Indian population. A transparent colour formula with definite proportioning of intrinsic pigments is provided for obtaining an aesthetic match to skin tone. PMID:27190946

  15. Intrinsic Disorder in the BK Channel and Its Interactome

    PubMed Central

    Peng, Zhenling; Sakai, Yoshihisa; Kurgan, Lukasz; Sokolowski, Bernd; Uversky, Vladimir

    2014-01-01

    The large-conductance Ca2+-activated K+ (BK) channel is broadly expressed in various mammalian cells and tissues such as neurons, skeletal and smooth muscles, exocrine cells, and sensory cells of the inner ear. Previous studies suggest that BK channels are promiscuous binders involved in a multitude of protein-protein interactions. To gain a better understanding of the potential mechanisms underlying BK interactions, we analyzed the abundance, distribution, and potential mechanisms of intrinsic disorder in 27 BK channel variants from mouse cochlea, 104 previously reported BK-associated proteins (BKAPS) from cytoplasmic and membrane/cytoskeletal regions, plus BK β- and γ-subunits. Disorder was evaluated using the MFDp algorithm, which is a consensus-based predictor that provides a strong and competitive predictive quality and PONDR, which can determine long intrinsically disordered regions (IDRs). Disorder-based binding sites or molecular recognition features (MoRFs) were found using MoRFpred and ANCHOR. BKAP functions were categorized based on Gene Ontology (GO) terms. The analyses revealed that the BK variants contain a number of IDRs. Intrinsic disorder is also common in BKAPs, of which ∼5% are completely disordered. However, intrinsic disorder is very differently distributed within BK and its partners. Approximately 65% of the disordered segments in BK channels are long (IDRs) (>50 residues), whereas >60% of the disordered segments in BKAPs are short IDRs that range in length from 4 to 30 residues. Both α and γ subunits showed various amounts of disorder as did hub proteins of the BK interactome. Our analyses suggest that intrinsic disorder is important for the function of BK and its BKAPs. Long IDRs in BK are engaged in protein-protein and protein-ligand interactions, contain multiple post-translational modification sites, and are subjected to alternative splicing. The disordered structure of BK and its BKAPs suggests one of the underlying mechanisms of

  16. Intrinsic Motivation and Learning in a Schizophrenia Spectrum Sample

    PubMed Central

    Choi, Jimmy; Medalia, Alice

    2009-01-01

    Amotivation is a telling hallmark of negative symptomatology in schizophrenia, and it impacts nearly every facet of behavior, including inclination to attempt the difficult cognitive tasks involved in cognitive remediation therapy. Experiences of external reward, reinforcement, and hedonic anticipatory enjoyment are diminished in psychosis, so therapeutics which instead target intrinsic motivation for cognitive tasks may enhance task engagement, and subsequently, remediation outcome. We examined whether outpatients could attain benefits from an intrinsically motivating instructional approach which (a) presents learning materials in a meaningful game-like context, (b) personalizes elements of the learning materials into themes of high interest value, and (c) offers choices so patients can increase their control over the learning process. We directly compared one learning method that incorporated the motivational paradigm into an arithmetic learning program against another method that carefully manipulated out the motivational variables in the same learning program. Fifty-seven subjects with schizophrenia or schizoaffective disorder were randomly assigned to one of the two learning programs for 10 thirty-minute sessions while an intent-to-treat convenience subsample (n=15) was used to account for practice effect. Outcome measures were arithmetic learning, attention, motivation, self competency, and symptom severity. Results showed the motivational group (a) acquired more arithmetic skill, (b) possessed greater intrinsic motivation for the task, (c) reported greater feelings of self competency post-treatment, and (d) demonstrated better post-test attention. Interestingly, baseline perception of self competency was a significant predictor of post-test arithmetic scores. Results demonstrated that incorporating intrinsically motivating instructional techniques into a difficult cognitive task promoted greater learning of the material, higher levels of intrinsic motivation

  17. University Builders.

    ERIC Educational Resources Information Center

    Pearce, Martin

    This publication explores a diverse collection of new university buildings. Ranging from the design of vast new campuses, such as that by Wilford and Stirling at Temasek, Singapore, through to the relatively modest yet strategically important, such as the intervention by Allies and Morrison at Southampton, this book examines the new higher…

  18. Universities 2035

    ERIC Educational Resources Information Center

    Thrift, Nigel

    2016-01-01

    This paper examines the future of Western higher education. Situated midway between an analysis and a polemic, it concerns itself with how we might begin to actively design the universities of the future. That will require a productionist account of higher education which is so far sadly lacking. But there are signs that such an account might be…

  19. Universal Studies.

    ERIC Educational Resources Information Center

    Kobryn, Nancy M.

    Universal Studies, a study program designed to help students develop emotionally, intellectually, and spiritually, is described. Development of the personality and character of the individual is emphasized, as are innovation, creativity, individualized instruction, independent learning, and realizing human potential. These goals are characterized…

  20. Widener University

    ERIC Educational Resources Information Center

    Valesey, Brigitte; Allen, Jo

    2009-01-01

    Founded in 1821, Widener University is a two-state (Pennsylvania and Delaware), four-campus, eight-college private institution serving approximately 6,700 students. Following arrival of the new senior vice president and provost in 2004 and subsequent reorganization of vice presidential responsibilities, Student Affairs is now led by a dean of…

  1. Hunting for Intrinsically X-ray Weak Quasars: The Case of PHL 1811 Analogs

    NASA Astrophysics Data System (ADS)

    Brandt, William

    2009-09-01

    A central dogma of X-ray astronomy is that luminous X-ray emission is a universal property of efficiently accreting supermassive black holes. One interesting challenge to this idea has come from the quasar PHL 1811 which appears to be intrinsically X-ray weak and also has distinctive emission-line properties. We propose to observe a sample of eight SDSS quasars, selected to have similar UV emission-line properties to that of PHL 1811, to test if they are also X-ray weak. Our analyses of the currently available X-ray data appear to support this hypothesis but do not provide a proper test. Our results will have implications for the nature of accretion-disk coronae, emission-line formation, and AGN selection.

  2. Extra-electron induced covalent strengthening and generalization of intrinsic ductile-to-brittle criterion

    PubMed Central

    Niu, Haiyang; Chen, Xing-Qiu; Liu, Peitao; Xing, Weiwei; Cheng, Xiyue; Li, Dianzhong; Li, Yiyi

    2012-01-01

    Traditional strengthening ways, such as strain, precipitation, and solid-solution, come into effect by pinning the motion of dislocation. Here, through first-principles calculations we report on an extra-electron induced covalent strengthening mechanism, which alters chemical bonding upon the introduction of extra-valence electrons in the matrix of parent materials. It is responsible for the brittle and high-strength properties of Al12W-type compounds featured by the typical fivefold icosahedral cages, which are common for quasicrystals and bulk metallic glasses (BMGs). In combination with this mechanism, we generalize ductile-to-brittle criterion in a universal hyperbolic form by integrating the classical Pettifor's Cauchy pressure with Pugh's modulus ratio for a wide variety of materials with cubic lattices. This study provides compelling evidence to correlate Pugh's modulus ratio with hardness of materials and may have implication for understanding the intrinsic brittleness of quasicrystals and BMGs. PMID:23056910

  3. Intrinsic Advance Primers: An Investigation of the Effects of Personalized Extraneous Multimedia upon Intrinsic Interest and Student Achievement

    ERIC Educational Resources Information Center

    Williams, Matthew Anthony

    2012-01-01

    The purpose of this study was to investigate if the delivery of personalized extraneous multimedia (PEM) messages prior to the delivery of the primary instructional materials could prime intrinsic interest and have a positive impact upon achievement in comparison to the use of non-personalized extraneous multimedia (NPEM). Extraneous materials are…

  4. Viscous dark fluid universe

    SciTech Connect

    Hipolito-Ricaldi, W. S.; Velten, H. E. S.; Zimdahl, W.

    2010-09-15

    We investigate the cosmological perturbation dynamics for a universe consisting of pressureless baryonic matter and a viscous fluid, the latter representing a unified model of the dark sector. In the homogeneous and isotropic background the total energy density of this mixture behaves as a generalized Chaplygin gas. The perturbations of this energy density are intrinsically nonadiabatic and source relative entropy perturbations. The resulting baryonic matter power spectrum is shown to be compatible with the 2dFGRS and SDSS (DR7) data. A joint statistical analysis, using also Hubble-function and supernovae Ia data, shows that, different from other studies, there exists a maximum in the probability distribution for a negative present value q{sub 0{approx_equal}}-0.53 of the deceleration parameter. Moreover, while previous descriptions on the basis of generalized Chaplygin-gas models were incompatible with the matter power-spectrum data since they required a much too large amount of pressureless matter, the unified model presented here favors a matter content that is of the order of the baryonic matter abundance suggested by big-bang nucleosynthesis.

  5. Expanding Universe

    NASA Astrophysics Data System (ADS)

    Schrödinger, E.

    2011-02-01

    Preface; Part I. The de Sitter Universe: 1. Synthetic construction; 2. The reduced model: geodesics; 3. The elliptic interpretation; 4. The static frame; 5. The determination of parallaxes; 6. The Lemaître-Robertson frame; Part II. The Theory of Geodesics: 7. On null geodesics; i. Determination of the parameter for null lines in special cases; ii. Frequency shift; 8. Free particles and light rays in general expanding spaces, flat or hyperspherical; i. Flat spaces; ii. Spherical spaces; iii. The red shift for spherical spaces; Part III. Waves in General Riemannian Space-Time: 9. The nature of our approximation; 10. The Hamilton-Jacobi theory in a gravitational field; 11. Procuring approximate solutions of the Hamilton-Jacobi equation from wave theory; Part IV. Waves in an Expanding Universe: 12. General considerations; 13. Proper vibrations and wave parcels; Bibliography.

  6. The Quest for "Economic Relevance" by US Research Universities

    ERIC Educational Resources Information Center

    Geiger, Roger L.

    2006-01-01

    Universities in the United States for at least the last century have made positive contributions to the economic weal, whether through their intrinsic mission of teaching and research or through special arrangements for service activities. In recent years there has been heightened awareness of the special role of academic research among…

  7. Job Satisfaction of Employees at a Christian University

    ERIC Educational Resources Information Center

    Schroder, Ralph

    2008-01-01

    As part of this quantitative study, a survey questionnaire was mailed out to 835 university employees to measure levels of overall, intrinsic, and extrinsic job satisfaction. The survey included items of the Professional Satisfaction Scale, an instrument developed according to Herzberg's two-factor theory. Responses were measured on a 5-point…

  8. University lobbying

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    In the past year, an increasing number of individual academic institutions have lobbied in Congress for new science facilities funds thus circumventing the traditional peer review process of evaluating the merits of such facilities. As an attempt to stem this rising tide, the National Academy of Sciences (NAS) governing council and the Association of American Universities (AAU) recently and independently issued strong statements condemning lobbying by individual universities and enthusiastically supporting the peer review system.“Informed peer judgments on the scientific merits of specific proposals, in open competition, should be a central element in the awarding of all federal funds for science,” the NAS resolution stated. AAU, meanwhile, implored “scientists, leaders of America's universities, and members of Congress” to “refrain from actions that would make scientific decisions a test of political influence rather than a judgment on the quality of the work to be done.” Roughly 50 research institutions constitute AAU; the two AAU Canadian members did not vote on the consortium's statement.

  9. Intrinsic Josephson effect and single Cooper pair tunneling

    NASA Astrophysics Data System (ADS)

    Yamashita, Tsutomu; Kim, Sang-Jae; Latyshev, Yuri; Nakajima, Kensuke

    2000-06-01

    We proposed a new, small and fast switching gate based on the intrinsic Josephson effect of single crystals of a cuprate superconductor. The switching time is of subpicosecond order, and the operating frequency is up to several terahertz. We used the focused-ion-beam (FIB) method for the fabrication of small Bi 2Sr 2CaCu 2O 8 (Bi-2212) stacked intrinsic Josephson junctions (IJJ) with in-plane size down to the submicron level without the degradation of their Tc. We observed clear Fraunhofer patterns in Ic- B curves and flux-flow velocity of up to 10 6 m/s for the stack junctions with the size of several micrometer scale. For the submicron junction, the low-temperature behavior is governed by the Coulomb-charging effects. This is the first observation of the Coulomb-charging effects in layered high- Tc materials.

  10. Determination of intrinsic ferroelectric polarization in lossy improper ferroelectric systems

    NASA Astrophysics Data System (ADS)

    Chowdhury, Ujjal; Goswami, Sudipta; Bhattacharya, Dipten; Midya, Arindam; Mandal, P.

    2016-08-01

    We measured the intrinsic hysteretic polarization in lossy improper and nanoferroelectric systems where the nonhysteretic polarization and leakage are large and the relaxation takes place over a broader time scale. We used different measurement protocols such as standard single triangular voltage pulse, a pulse train of Positive Up Negative Down, and an even more complicated pulse train of fourteen voltage pulses and compared the results obtained. We show that a protocol which sends a train of fourteen pulses is more appropriate for extracting relaxed (i.e., time scale independent) and intrinsic remanent polarization for these samples. We also point out that it is possible to select and design an appropriate measurement protocol depending on the magnitude of polarization and leakage of the system.

  11. Intrinsic fluorescence of selenium nanoparticles for cellular imaging applications.

    PubMed

    Khalid, A; Tran, Phong A; Norello, Romina; Simpson, David A; O'Connor, Andrea J; Tomljenovic-Hanic, Snjezana

    2016-02-14

    Nanoparticles hold great potential in contributing to high-resolution bioimaging as well as for biomedical applications. Although, selenium (Se) nanoparticles (NPs) have been investigated owing to their potential roles in therapeutics, the imaging capability of these NPs has never been explored. This manuscript identifies the intrinsic fluorescence of Se NPs, which is highly beneficial for nanoscale imaging of biological structures. The emission of individual NPs and its evolution with time is explored. The photoluminescence spectra has revealed visible to near infrared emission for Se NPs. The work finally reflects on the role of this intrinsic fluorescence for in vitro imaging and tracking in fibroblast cells, without the need of any additional tags. This technique would overcome the limitations of the conventionally used methods of imaging with tagged fluorescent proteins and dyes, preventing possible adverse cellular effects or phototoxicity caused by the added fluorescent moieties. PMID:26792107

  12. Intrinsic borohydride fuel cell/battery hybrid power sources

    NASA Astrophysics Data System (ADS)

    Hong, Jian; Fang, Bin; Wang, Chunsheng; Currie, Kenneth

    The electrochemical oxidation behaviors of NaBH 4 on Zn, Zn-MH, and MH (metal-hydride) electrodes were investigated, and an intrinsic direct borohydride fuel cell (DBFC)/battery hybrid power source using MH (or Zn-MH) as the anode and MnO 2 as the cathode was tested. Borohydride cannot be effectively oxidized on Zn electrodes at the Zn oxidation potential because of the poor electrocatalytic ability of Zn for borohydride oxidation and the high overpotential, even though borohydride has the same oxidation potential of Zn in an alkaline solution. The borohydride can be electrochemically oxidized on Ni and MH electrodes through a 4e reaction at a high overpotential. Simply adding borohydride into an alkaline electrolyte of a Zn/air or MH/air battery can greatly increase the capacity, while an intrinsic DBFC/MH(or Zn)-MnO 2 battery can deliver a higher peak power than regular DBFCs.

  13. Quantum-thermodynamic treatment of intrinsic anharmonicity; Wallace's theorem revisited

    NASA Astrophysics Data System (ADS)

    Jacobs, Michel H. G.; de Jong, Bernard H. W. S.

    2005-12-01

    Wallace (in Thermodynamics of crystals, 1972) developed a theorem, rooted in rigid lattice dynamics, which incorporates intrinsic anharmonic effects in solids. The practical application of this theorem in mineral physics is computationally involved and this is the main reason for the theorem not getting the attention it deserves. Because intrinsic anharmonicity is an important issue at the extreme conditions in planetary mantles, we derived a method which removes the computational obstacles in applying this theorem. We extended the theorem to incorporate details of the phonon spectrum and tested our algorithm on forsterite (Mg2SiO4). Using a least squares inversion technique applied to all available experimental data, we show that it results in an accurate representation of thermodynamic properties and sound wave velocities of Mg2SiO4 in its complete pressure-temperature stability range. We also show that the accuracy of our results is not significantly affected by the use of a different equation of state.

  14. A Modified Theoretical Model of Intrinsic Hardness of Crystalline Solids

    PubMed Central

    Dai, Fu-Zhi; Zhou, Yanchun

    2016-01-01

    Super-hard materials have been extensively investigated due to their practical importance in numerous industrial applications. To stimulate the design and exploration of new super-hard materials, microscopic models that elucidate the fundamental factors controlling hardness are desirable. The present work modified the theoretical model of intrinsic hardness proposed by Gao. In the modification, we emphasize the critical role of appropriately decomposing a crystal to pseudo-binary crystals, which should be carried out based on the valence electron population of each bond. After modification, the model becomes self-consistent and predicts well the hardness values of many crystals, including crystals composed of complex chemical bonds. The modified model provides fundamental insights into the nature of hardness, which can facilitate the quest for intrinsic super-hard materials. PMID:27604165

  15. Intrinsic disorder in graphene on transition metal dichalcogenide heterostructures

    NASA Astrophysics Data System (ADS)

    Yankowitz, Matthew; Larentis, Stefano; Kim, Kyounghwam; Xue, Jiamin; McKenzie, Devin; Huang, Shengqiang; Paggen, Marina; Ali, Mazhar; Cava, Robert; Tutuc, Emanuel; Leroy, Brian J.

    2015-03-01

    Recently, semiconducting materials in the transition metal dichalcogenide (TMD) family have gained great popularity for use in novel graphene-based heterostructure devices such as tunneling transistors, highly efficient flexible photovoltaic devices, and nonvolatile memory cells. TMDs have also been explored as alternatives to hexagonal boron nitride (hBN) as substrates for pristine graphene devices. However, their quality has thus far been significantly worse than comparable hBN devices. We examine graphene on numerous TMD substrates (MoS2, WS2, WSe2, MoTe2) with scanning tunneling microscopy and spectroscopy and find that point and line defects intrinsic to all TMD crystals (both of natural and synthetic origin) result in scattering of electrons in graphene. Our findings suggest that the quality of graphene on TMD heterostructures is limited by the intrinsic crystalline quality of the TMDs.

  16. Intrinsic and extrinsic mechanisms regulating satellite cell function.

    PubMed

    Dumont, Nicolas A; Wang, Yu Xin; Rudnicki, Michael A

    2015-05-01

    Muscle stem cells, termed satellite cells, are crucial for skeletal muscle growth and regeneration. In healthy adult muscle, satellite cells are quiescent but poised for activation. During muscle regeneration, activated satellite cells transiently re-enter the cell cycle to proliferate and subsequently exit the cell cycle to differentiate or self-renew. Recent studies have demonstrated that satellite cells are heterogeneous and that subpopulations of satellite stem cells are able to perform asymmetric divisions to generate myogenic progenitors or symmetric divisions to expand the satellite cell pool. Thus, a complex balance between extrinsic cues and intrinsic regulatory mechanisms is needed to tightly control satellite cell cycle progression and cell fate determination. Defects in satellite cell regulation or in their niche, as observed in degenerative conditions such as aging, can impair muscle regeneration. Here, we review recent discoveries of the intrinsic and extrinsic factors that regulate satellite cell behaviour in regenerating and degenerating muscles.

  17. The detrimental effects of extrinsic reinforcement on "Intrinsic motivation".

    PubMed

    Dickinson, A M

    1989-01-01

    Extrinsic consequences have been criticized on the grounds that they decrease intrinsic motivation or internally initiated behavior. Two popular rationales for this criticism, Lepper's overjustification hypothesis (1981) and Deci's motivational theory (Deci & Ryan, 1985), are reviewed and the criticism is then redefined behaviorally. "Intrinsically controlled" behavior is defined as behavior maintained by response-produced reinforcers, and the question concerning extrinsic consequences is thus restated as follows: When behavior is maintained by response-produced stimuli, does extrinsic reinforcement decrease the reinforcing value of those stimuli? The empirical support for this detrimental effect is summarized briefly, and several possible explanations for the phenomenon are offered. Research results that reflect on the effect's generality and social significance are discussed next, with the conclusion that the effect is transient and not likely to occur at all if extrinsic rewards are reinforcing, noncompetitive, based on reasonable performance standards, and delivered repetitively.

  18. Intrinsic Negative Poisson's Ratio for Single-Layer Graphene.

    PubMed

    Jiang, Jin-Wu; Chang, Tienchong; Guo, Xingming; Park, Harold S

    2016-08-10

    Negative Poisson's ratio (NPR) materials have drawn significant interest because the enhanced toughness, shear resistance, and vibration absorption that typically are seen in auxetic materials may enable a range of novel applications. In this work, we report that single-layer graphene exhibits an intrinsic NPR, which is robust and independent of its size and temperature. The NPR arises due to the interplay between two intrinsic deformation pathways (one with positive Poisson's ratio, the other with NPR), which correspond to the bond stretching and angle bending interactions in graphene. We propose an energy-based deformation pathway criteria, which predicts that the pathway with NPR has lower energy and thus becomes the dominant deformation mode when graphene is stretched by a strain above 6%, resulting in the NPR phenomenon. PMID:27408994

  19. The intrinsic bispectrum of the cosmic microwave background

    SciTech Connect

    Pettinari, Guido W.; Fidler, Christian; Crittenden, Robert; Koyama, Kazuya; Wands, David E-mail: Christian.Fidler@port.ac.uk E-mail: Kazuya.Koyama@port.ac.uk

    2013-04-01

    We develop a new, efficient code for solving the second-order Einstein-Boltzmann equations, and use it to estimate the intrinsic CMB non-Gaussianity arising from the non-linear evolution of density perturbations. The full calculation involves contributions from recombination and less tractable contributions from terms integrated along the line of sight. We investigate the bias that this intrinsic bispectrum implies for searches of primordial non-Gaussianity. We find that the inclusion or omission of certain line of sight terms can make a large impact. When including all physical effects but lensing and time-delay, we find that the local-type f{sub NL} would be biased by f{sub NL}{sup intra} = 0.5, below the expected sensitivity of the Planck satellite. The speed of our code allows us to confirm the robustness of our results with respect to a number of numerical parameters.

  20. Finding intrinsic rewards by embodied evolution and constrained reinforcement learning.

    PubMed

    Uchibe, Eiji; Doya, Kenji

    2008-12-01

    Understanding the design principle of reward functions is a substantial challenge both in artificial intelligence and neuroscience. Successful acquisition of a task usually requires not only rewards for goals, but also for intermediate states to promote effective exploration. This paper proposes a method for designing 'intrinsic' rewards of autonomous agents by combining constrained policy gradient reinforcement learning and embodied evolution. To validate the method, we use Cyber Rodent robots, in which collision avoidance, recharging from battery packs, and 'mating' by software reproduction are three major 'extrinsic' rewards. We show in hardware experiments that the robots can find appropriate 'intrinsic' rewards for the vision of battery packs and other robots to promote approach behaviors. PMID:19013054

  1. Time domain optical susceptibility of intrinsic GaAs

    NASA Astrophysics Data System (ADS)

    Thomas, M. E.; Miragliotta, J. A.; Joseph, R. I.

    2002-06-01

    Intrinsic GaAs optical constant values are well known as functions of frequency (10 000-65 000 cm-1 or 1.24-8.06 eV) and temperature (22-754 K). Room-temperature far-infrared optical constant data also exist as a function of frequency, and are representable by a classical oscillator model. In this article, the frequency-domain, temperature-dependent intrinsic dielectric function of GaAs has been Fourier transformed to obtain an analytical, closed-form representation of the time-domain susceptibility. Results from these expressions are consistent with the temporal characteristics of electronic transitions impeded by elastic scattering, which are in the femtosecond regime. The closed form nature of these expressions makes them well suited for finite difference time domain simulations of waveguides, optoelectronic devices, and microwave devices.

  2. Magnetic alignment of block copolymer microdomains by intrinsic chain anisotropy

    SciTech Connect

    Rokhlenko, Yekaterina; Yager, Kevin G.; Gopinadhan, Manesh; Osuji, Chinedum O.; Zhang, Kai; O'Hern, Corey S.; Larson, Steven R.; Gopalan, Padma; Majewski, Pawel W.

    2015-12-18

    We examine the role of intrinsic chain susceptibility anisotropy in magnetic field directed self-assembly of a block copolymer using in situ x-ray scattering. Alignment of a lamellar mesophase is observed on cooling across the disorder-order transition with the resulting orientational order inversely proportional to the cooling rate. We discuss the origin of the susceptibility anisotropy, Δχ, that drives alignment and calculate its magnitude using coarse-grained molecular dynamics to sample conformations of surface-tethered chains, finding Δχ ≈ 2×10–8. From field-dependent scattering data, we estimate that grains of ≈ 1.2 μm are present during alignment. Furthermore, these results demonstrate that intrinsic anisotropy is sufficient to support strong field-induced mesophase alignment and suggest a versatile strategy for field control of orientational order in block copolymers.

  3. Magnetic alignment of block copolymer microdomains by intrinsic chain anisotropy

    DOE PAGESBeta

    Rokhlenko, Yekaterina; Yager, Kevin G.; Gopinadhan, Manesh; Osuji, Chinedum O.; Zhang, Kai; O'Hern, Corey S.; Larson, Steven R.; Gopalan, Padma; Majewski, Pawel W.

    2015-12-18

    We examine the role of intrinsic chain susceptibility anisotropy in magnetic field directed self-assembly of a block copolymer using in situ x-ray scattering. Alignment of a lamellar mesophase is observed on cooling across the disorder-order transition with the resulting orientational order inversely proportional to the cooling rate. We discuss the origin of the susceptibility anisotropy, Δχ, that drives alignment and calculate its magnitude using coarse-grained molecular dynamics to sample conformations of surface-tethered chains, finding Δχ ≈ 2×10–8. From field-dependent scattering data, we estimate that grains of ≈ 1.2 μm are present during alignment. Furthermore, these results demonstrate that intrinsic anisotropymore » is sufficient to support strong field-induced mesophase alignment and suggest a versatile strategy for field control of orientational order in block copolymers.« less

  4. Improved intrinsic resolution: does it make a difference. concise communication

    SciTech Connect

    Hoffer, P.B.; Neumann, R.; Quartararo, L.; Lange, R.; Hernandez, T.

    1984-02-01

    The purpose of this study was to determine what effect further improvement in an Anger camera's intrinsic resolution has on lesion detection. We studied 52 patients undergoing bone imaging and 58 undergoing liver imaging. All patients had images performed in rapid sequence on ZLC-75 and ZLC-37 Anger cameras, both by Siemens. The two imaging systems are virtually identical except for the number of photomultiplier tubes and crystal thickness; these resulted in differences in intrinsic resolution and sensitivity. Observer performance, measured by ROC curves, for detection of abnormalities was virtually identical with the two instruments. Subjectively, there was a trend toward preference of the ZLC-75 images, but this was not associated with any significant improvement in lesion detectability even in the subgroup in which a preference for one or the other instrument was noted.

  5. Intrinsic oscillations of neocortex generated by layer 5 pyramidal neurons.

    PubMed

    Silva, L R; Amitai, Y; Connors, B W

    1991-01-25

    Rhythmic activity in the neocortex varies with different behavioral and pathological states and in some cases may encode sensory information. However, the neural mechanisms of these oscillations are largely unknown. Many pyramidal neurons in layer 5 of the neocortex showed prolonged, 5- to 12-hertz rhythmic firing patterns at threshold. Rhythmic firing was due to intrinsic membrane properties, sodium conductances were essential for rhythmicity, and calcium-dependent conductances strongly modified rhythmicity. Isolated slices of neocortex generated epochs of 4- to 10-hertz synchronized activity when N-methyl-D-aspartate receptor-mediated channels were facilitated. Layer 5 was both necessary and sufficient to produce these synchronized oscillations. Thus, synaptic networks of intrinsically rhythmic neurons in layer 5 may generate or promote certain synchronized oscillations of the neocortex.

  6. The Intrinsic Ferromagnetism in a MnO2 Monolayer.

    PubMed

    Kan, M; Zhou, J; Sun, Q; Kawazoe, Y; Jena, P

    2013-10-17

    The Mn atom, because of its special electronic configuration of 3d(5)4s(2), has been widely used as a dopant in various two-dimensional (2D) monolayers such as graphene, BN, silicene and transition metal dichalcogenides (TMDs). The distributions of doped Mn atoms in these systems are highly sensitive to the synthesis process and conditions, thus suffering from problems of low solubility and surface clustering. Here we show for the first time that the MnO2 monolayer, synthetized 10 years ago, where Mn ions are individually held at specific sites, exhibits intrinsic ferromagnetism with a Curie temperature of 140 K, comparable to the highest TC value achieved experimentally for Mn-doped GaAs. The well-defined atomic configuration and the intrinsic ferromagnetism of the MnO2 monolayer suggest that it is superior to other magnetic monolayer materials.

  7. Resonant wave-particle interactions modified by intrinsic Alfvenic turbulence

    SciTech Connect

    Wu, C. S.; Lee, K. H.; Wang, C. B.; Wu, D. J.

    2012-08-15

    The concept of wave-particle interactions via resonance is well discussed in plasma physics. This paper shows that intrinsic Alfven waves can qualitatively modify the physics discussed in conventional linear plasma kinetic theories. It turns out that preexisting Alfven waves can affect particle motion along the ambient magnetic field and, moreover, the ensuing force field is periodic in time. As a result, the meaning of the usual Landau and cyclotron resonance conditions becomes questionable. It turns out that this effect leads us to find a new electromagnetic instability. In such a process intrinsic Alfven waves not only modify the unperturbed distribution function but also result in a different type of cyclotron resonance which is affected by the level of turbulence. This instability might enable us to better our understanding of the observed radio emission processes in the solar atmosphere.

  8. Hot carrier-assisted intrinsic photoresponse in graphene.

    PubMed

    Gabor, Nathaniel M; Song, Justin C W; Ma, Qiong; Nair, Nityan L; Taychatanapat, Thiti; Watanabe, Kenji; Taniguchi, Takashi; Levitov, Leonid S; Jarillo-Herrero, Pablo

    2011-11-01

    We report on the intrinsic optoelectronic response of high-quality dual-gated monolayer and bilayer graphene p-n junction devices. Local laser excitation (of wavelength 850 nanometers) at the p-n interface leads to striking six-fold photovoltage patterns as a function of bottom- and top-gate voltages. These patterns, together with the measured spatial and density dependence of the photoresponse, provide strong evidence that nonlocal hot carrier transport, rather than the photovoltaic effect, dominates the intrinsic photoresponse in graphene. This regime, which features a long-lived and spatially distributed hot carrier population, may offer a path to hot carrier-assisted thermoelectric technologies for efficient solar energy harvesting.

  9. Magnetic Alignment of Block Copolymer Microdomains by Intrinsic Chain Anisotropy

    NASA Astrophysics Data System (ADS)

    Rokhlenko, Yekaterina; Gopinadhan, Manesh; Osuji, Chinedum O.; Zhang, Kai; O'Hern, Corey S.; Larson, Steven R.; Gopalan, Padma; Majewski, Paweł W.; Yager, Kevin G.

    2015-12-01

    We examine the role of intrinsic chain susceptibility anisotropy in magnetic field directed self-assembly of a block copolymer using in situ x-ray scattering. Alignment of a lamellar mesophase is observed on cooling across the disorder-order transition with the resulting orientational order inversely proportional to the cooling rate. We discuss the origin of the susceptibility anisotropy, Δ χ , that drives alignment and calculate its magnitude using coarse-grained molecular dynamics to sample conformations of surface-tethered chains, finding Δ χ ≈2 ×1 0-8. From field-dependent scattering data, we estimate that grains of ≈1.2 μ m are present during alignment. These results demonstrate that intrinsic anisotropy is sufficient to support strong field-induced mesophase alignment and suggest a versatile strategy for field control of orientational order in block copolymers.

  10. Probing intrinsic anisotropies of fluorescence: Mueller matrix approach.

    PubMed

    Saha, Sudipta; Soni, Jalpa; Chandel, Shubham; Kumar, Uday; Ghosh, Nirmalya

    2015-08-01

    We demonstrate that information on “intrinsic” anisotropies of fluorescence originating from preferential orientation/organization of fluorophore molecules can be probed using a Mueller matrix of fluorescence. For this purpose, we have developed a simplified model to decouple and separately quantify the depolarization property and the intrinsic anisotropy properties of fluorescence from the experimentally measured fluorescence Mueller matrix. Unlike the traditionally defined fluorescence anisotropy parameter, the Mueller matrix-derived fluorescence polarization metrics, namely, fluorescence diattenuation and polarizance parameters, exclusively deal with the intrinsic anisotropies of fluorescence. The utility of these newly derived fluorescence polarimetry parameters is demonstrated on model systems exhibiting multiple polarimetry effects, and an interesting example is illustrated on biomedically important fluorophores, collagen. PMID:26301796

  11. A Modified Theoretical Model of Intrinsic Hardness of Crystalline Solids

    NASA Astrophysics Data System (ADS)

    Dai, Fu-Zhi; Zhou, Yanchun

    2016-09-01

    Super-hard materials have been extensively investigated due to their practical importance in numerous industrial applications. To stimulate the design and exploration of new super-hard materials, microscopic models that elucidate the fundamental factors controlling hardness are desirable. The present work modified the theoretical model of intrinsic hardness proposed by Gao. In the modification, we emphasize the critical role of appropriately decomposing a crystal to pseudo-binary crystals, which should be carried out based on the valence electron population of each bond. After modification, the model becomes self-consistent and predicts well the hardness values of many crystals, including crystals composed of complex chemical bonds. The modified model provides fundamental insights into the nature of hardness, which can facilitate the quest for intrinsic super-hard materials.

  12. Intrinsic and extrinsic mechanisms regulating satellite cell function

    PubMed Central

    Dumont, Nicolas A.; Wang, Yu Xin; Rudnicki, Michael A.

    2015-01-01

    Muscle stem cells, termed satellite cells, are crucial for skeletal muscle growth and regeneration. In healthy adult muscle, satellite cells are quiescent but poised for activation. During muscle regeneration, activated satellite cells transiently re-enter the cell cycle to proliferate and subsequently exit the cell cycle to differentiate or self-renew. Recent studies have demonstrated that satellite cells are heterogeneous and that subpopulations of satellite stem cells are able to perform asymmetric divisions to generate myogenic progenitors or symmetric divisions to expand the satellite cell pool. Thus, a complex balance between extrinsic cues and intrinsic regulatory mechanisms is needed to tightly control satellite cell cycle progression and cell fate determination. Defects in satellite cell regulation or in their niche, as observed in degenerative conditions such as aging, can impair muscle regeneration. Here, we review recent discoveries of the intrinsic and extrinsic factors that regulate satellite cell behaviour in regenerating and degenerating muscles. PMID:25922523

  13. Quasiparticle current and phase locking of intrinsic Josephson junctions

    NASA Astrophysics Data System (ADS)

    Seidel, P.; Grib, A. N.; Shukrinov, Yu. M.; Scherbel, J.; Hübner, U.; Schmidl, F.

    2001-09-01

    On the base of our experiments on thin film Josephson junctions in mesa geometry we discuss the quasiparticle branches of the intrinsic arrays within a tunnelling model using d-wave superconductor density of states. We find temperature dependent current contributions and a zero bias anomaly. The coherent behaviour is studied for intrinsic arrays with an additional side-wall shunt. The existence of thresholds of phase locking at small as well as at large inductances is demonstrated. We discuss the problems with experimental realisation of the shunts as well as with an alternative concept to enhance phase locking in such arrays towards application as oscillators in the frequency range up to some THz.

  14. A Modified Theoretical Model of Intrinsic Hardness of Crystalline Solids.

    PubMed

    Dai, Fu-Zhi; Zhou, Yanchun

    2016-01-01

    Super-hard materials have been extensively investigated due to their practical importance in numerous industrial applications. To stimulate the design and exploration of new super-hard materials, microscopic models that elucidate the fundamental factors controlling hardness are desirable. The present work modified the theoretical model of intrinsic hardness proposed by Gao. In the modification, we emphasize the critical role of appropriately decomposing a crystal to pseudo-binary crystals, which should be carried out based on the valence electron population of each bond. After modification, the model becomes self-consistent and predicts well the hardness values of many crystals, including crystals composed of complex chemical bonds. The modified model provides fundamental insights into the nature of hardness, which can facilitate the quest for intrinsic super-hard materials. PMID:27604165

  15. The dirty side of the intrinsic pathway of coagulation.

    PubMed

    Cooley, Brian C

    2016-09-01

    Whereas the extrinsic pathway of coagulation seals off bleeding at the cut tissue edges, it is proposed that the intrinsic pathway exploits the dirt from the skin surface to generate an outer coagulum of the oozing blood. Activated Factor XII (FXIIa) in this outer cap generates Factor XIa, which triggers clotting, and kallikrein that feeds back to form more FXIIa to promote the process. This dirty-wound hypothesis of coagulation function by the intrinsic pathway is supported by the use of dirt-based compounds in activated partial thromboplastin time assays as well as the evolutionary record where marine life that do not have skin-adherent dirt lack Factor XII, including marine mammals that have returned to sea life. PMID:27373598

  16. Concept for the intrinsic dielectric strength of electrical insulation materials

    SciTech Connect

    Cuddihy, E.F.

    1985-04-15

    A concept is described for a possible definition of the intrinsic dielectric strength of insulating materials, which can be considered as a fundamental material property similar to other material properties, such as Young's modulus, index of refraction, and expansion coefficients. The events leading to the recognition of this property are reported, and the property is defined. This intrinsic dielectric strength concept should facilitate interpretation of results from accelerated and/or natural aging programs intended to predict electrical insulation service life of encapsulants in photovoltaic modules. As a practical application, this new concept enabled a possible explanation of the cause of failures in buried high-voltage cables with polyethylene insulation, and a possible explanation of the causes of electrical trees in polyethylene; these also are described.

  17. Macroscopic quantum effects in intrinsic Josephson junction stacks

    NASA Astrophysics Data System (ADS)

    Koyama, T.; Machida, M.

    2008-09-01

    A macroscopic quantum theory for the capacitively-coupled intrinsic Josephson junctions (IJJ’s) is constructed. We clarify the multi-junction effect for the macroscopic quantum tunneling (MQT) to the first resistive branch. It is shown that the escape rate is greatly enhanced by the capacitive coupling between junctions. We also discuss the origin of the N2-enhancement in the escape rate observed in the uniformly switching in Bi-2212 IJJ’s.

  18. Planar intrinsic Josephson junctions fabricated on Bi-2212 LPE films

    NASA Astrophysics Data System (ADS)

    Yasuda, Takashi; Kawae, Takeshi; Yamashita, Tsutomu; Taka, Chihiro; Nishida, Akihiko; Takano, Shuzo

    2003-05-01

    Planar design of intrinsic Josephson junctions (IJJs) is studied using Bi2Sr2CaCu2Ox (Bi-2212) films prepared by liquid phase epitaxy. Step-type IJJ stacks fabricated on step-patterned MgO substrates exhibit multibranched current-voltage characteristics inherent in Bi-2212 single crystals. This behavior is found to be limited to films on small-angle steps, suggesting the incorporation of defects near the steep steps of substrates.

  19. Illumination-dependent changes in the intrinsic fluorescence of bacteriorhodopsin

    NASA Technical Reports Server (NTRS)

    Bogomolni, R. A.; Stubbs, L.; Lanyi, J. K.

    1978-01-01

    The paper describes the intrinsic UV fluorescence of bacteriorhodopsin in some detail and determines the changes during the rapid cyclic reaction following light flashes. The results suggest that several tryptophan residues are affected in the protein, among them one or more exposed to aqueous medium. The kinetics of the fluorescence changes coincide closely with events involving the retinal residue during the deprotonation and reprotonation of the Schiff base group.

  20. Intrinsic fluorescence of selenium nanoparticles for cellular imaging applications

    NASA Astrophysics Data System (ADS)

    Khalid, A.; Tran, Phong A.; Norello, Romina; Simpson, David A.; O'Connor, Andrea J.; Tomljenovic-Hanic, Snjezana

    2016-02-01

    Nanoparticles hold great potential in contributing to high-resolution bioimaging as well as for biomedical applications. Although, selenium (Se) nanoparticles (NPs) have been investigated owing to their potential roles in therapeutics, the imaging capability of these NPs has never been explored. This manuscript identifies the intrinsic fluorescence of Se NPs, which is highly beneficial for nanoscale imaging of biological structures. The emission of individual NPs and its evolution with time is explored. The photoluminescence spectra has revealed visible to near infrared emission for Se NPs. The work finally reflects on the role of this intrinsic fluorescence for in vitro imaging and tracking in fibroblast cells, without the need of any additional tags. This technique would overcome the limitations of the conventionally used methods of imaging with tagged fluorescent proteins and dyes, preventing possible adverse cellular effects or phototoxicity caused by the added fluorescent moieties.Nanoparticles hold great potential in contributing to high-resolution bioimaging as well as for biomedical applications. Although, selenium (Se) nanoparticles (NPs) have been investigated owing to their potential roles in therapeutics, the imaging capability of these NPs has never been explored. This manuscript identifies the intrinsic fluorescence of Se NPs, which is highly beneficial for nanoscale imaging of biological structures. The emission of individual NPs and its evolution with time is explored. The photoluminescence spectra has revealed visible to near infrared emission for Se NPs. The work finally reflects on the role of this intrinsic fluorescence for in vitro imaging and tracking in fibroblast cells, without the need of any additional tags. This technique would overcome the limitations of the conventionally used methods of imaging with tagged fluorescent proteins and dyes, preventing possible adverse cellular effects or phototoxicity caused by the added fluorescent

  1. Disorder in milk proteins: caseins, intrinsically disordered colloids.

    PubMed

    Redwan, Elrashdy M; Xue, Bin; Almehdar, Hussein A; Uversky, Vladimir N

    2015-01-01

    This article opens a series of reviews on the abundance and roles of intrinsic disorder in milk proteins. The focus of this introductory article on caseins is symbolic, since caseins were among the first recognized functional unfolded proteins and since they are definitely the most disordered, the most abundant, and the most studied of all milk proteins. In eutherian milks, the casein family includes at least three and usually four major members (αs1-, αs2-, β-, and κ-caseins) that are unrelated in sequence. However, in some species, two different αS2-casein genes are active, and therefore the total number of caseins can be as high as five. These proteins have found a number of uses in food industry. The functional repertoire of caseins ranges from nutritional function to involvement in the improving and/or maintaining cardiovascular health, to crucial contribution to the milk capacity to transport calcium phosphate, to serve as molecular chaperones, and to protect the mother's mammary gland against amyloidoses and ectopic calcification. An intricate feature of caseins is their ability to assemble to colloidal protein particles, casein micelles, serving to sequester and transport amorphous calcium phosphate. These and many other functions of caseins are obviously dependent on their intrinsically disordered nature and are controlled by various posttranslational modifications. Since various aspects of casein structure and function are rather well studied and since several recent reviews emphasized the functional roles of caseins' intrinsic disorder, the major goal of this article is to show how intrinsic disorder is encoded in the amino acid sequences of these proteins.

  2. Intrinsic evolution of controllable oscillators in FPTA-2

    NASA Technical Reports Server (NTRS)

    Sekanina, Lukas; Zebulum, Ricardo S.

    2005-01-01

    Simple one- and two-bit controllable oscillators were intrinsically evolved using only four cells of Field Programmable Transistor Array (FPTA-2). These oscillators can produce different oscillations for different setting of control signals. Therefore, they could be used, in principle, to compose complex networks of oscillators that could exhibit rich dynamical behavior in order to perform a computation or to model a desired system.

  3. Acute kidney injury in sepsis: transient or intrinsic?

    PubMed

    Jörres, Achim

    2013-11-20

    The negative prediction of intrinsic versus transient acute kidney injury (AKI) in septic patients may be facilitated by combined assessment of fractional excretion of sodium and urea. If both excretions are high this would signal the presence of transient AKI and suggest that successful restoration of diuresis by conservative therapy is likely, thus supporting a wait-and-watch approach regarding the initiation of acute renal replacement therapy.

  4. Intrinsic DX Centers in Ternary Chalcopyrite Semiconductors (Presentation)

    SciTech Connect

    Lany, S.; Zunger, A.

    2008-05-01

    The conclusions of this report are: (1) intrinsic donor-type defects In{sub Cu}, Ga{sub Cu}, and V{sub Se}, and their complexes with V{sub Cu} cause metastability, but also act to limit V{sub OC}; (2) growth conditions which minimize these defects (Cu-rich/Se-rich) are very different from those currently used; and (3) overcoming V{sub OC} limitation requires to address other issues and trade-offs.

  5. Large-scale structure and the intrinsic alignment of galaxies

    NASA Astrophysics Data System (ADS)

    Blazek, Jonathan; Seljak, Uroš; Mandelbaum, Rachel

    2016-10-01

    Coherent alignments of galaxy shapes, often called``intrinsic alignments'' (IA), are the most significant source of astrophysical uncertainty in weak lensing measurements. We develop the tidal alignment model of IA and demonstrate its success in describing observational data. We also describe a technique to separate IA from galaxy-galaxy lensing measurements. Applying this technique to luminous red galaxy lenses in the Sloan Digital Sky Survey, we constrain potential IA contamination from associated sources to be below a few percent.

  6. Functionally-defined Therapeutic Targets in Diffuse Intrinsic Pontine Glioma

    PubMed Central

    Grasso, Catherine S.; Tang, Yujie; Truffaux, Nathalene; Berlow, Noah E.; Liu, Lining; Debily, Marie-Anne; Quist, Michael J.; Davis, Lara E.; Huang, Elaine C.; Woo, Pamelyn J; Ponnuswami, Anitha; Chen, Spenser; Johung, Tessa B.; Sun, Wenchao; Kogiso, Mari; Du, Yuchen; Lin, Qi; Huang, Yulun; Hütt-Cabezas, Marianne; Warren, Katherine E.; Dret, Ludivine Le; Meltzer, Paul S.; Mao, Hua; Quezado, Martha; van Vuurden, Dannis G.; Abraham, Jinu; Fouladi, Maryam; Svalina, Matthew N.; Wang, Nicholas; Hawkins, Cynthia; Nazarian, Javad; Alonso, Marta M.; Raabe, Eric; Hulleman, Esther; Spellman, Paul T.; Li, Xiao-Nan; Keller, Charles; Pal, Ranadip; Grill, Jacques; Monje, Michelle

    2015-01-01

    Diffuse Intrinsic Pontine Glioma (DIPG) is a fatal childhood cancer. We performed a chemical screen in patient-derived DIPG cultures along with RNAseq analyses and integrated computational modeling to identify potentially effective therapeutic strategies. The multi-histone deacetylase inhibitor panobinostat demonstrated efficacy in vitro and in DIPG orthotopic xenograft models. Combination testing of panobinostat with histone demethylase inhibitor GSKJ4 revealed synergy. Together, these data suggest a promising therapeutic strategy for DIPG. PMID:25939062

  7. On The intrinsic equation behind the Delaunay surfaces

    SciTech Connect

    Mladenov, Ivaielo M.; Hadzhilazova, Mariana Ts.; Djondjorov, Peter A.; Vassilev, Vassil M.

    2008-11-18

    By balancing the internal and external forces acting on axially symmetric membranes one arrives at a system of two equations describing the equilibrium states. This system allows at least two sets of analytical solutions. One of them presents the Euler's elasticas and the other one can be recognized as the class of Delaunay surfaces. The intrinsic equation describing the profile curves of the later is found and solved and this leads to new analytical formulas for these surfaces.

  8. Are There Intrinsically X-Ray Quiet Quasars

    NASA Technical Reports Server (NTRS)

    Gallagher, S. C.; Brandt, W. N.; Laor, A.; Elvis, Martin; Mathur, S.; Wills, Beverly J.; Iyomoto, N.; White, Nicholas (Technical Monitor)

    2000-01-01

    Recent ROSAT studies have identified a significant population of Active Galactic Nuclei (AGN) that are notably faint in soft X-rays relative to their optical fluxes. Are these AGN intrinsically X-ray weak or are they just highly absorbed? Brandt, Laor & Wills have systematically examined the optical and UV spectral properties of a well-defined sample of these soft X-ray weak (SXW) AGN drawn from the Boroson & Green sample of all the Palomar Green AGN 00 with z < 0.5. We present ASCA observations of three of these SXW AGN: PG 1011-040, PG 1535+547 (Mrk 486), and PG 2112+059. In general, our ASCA observations support the intrinsic absorption scenario for explaining soft X-ray weakness; both PG 1535+547 and PG 2112+059 show significant column densities (NH is approximately 10(exp 22) - 10(exp 23)/sq cm) of absorbing gas. Interestingly, PG 1011-040 shows no spectral evidence for X-ray absorption. The weak X-ray emission may result from very strong absorption of a partially covered source, or this AGN may be intrinsically X-ray weak. PG 2112+059 is a Broad Absorption Line (BAL) QSO, and we find it to have the highest X-ray flux known of this class. It shows a typical power-law X-ray continuum above 3 keV; this is the first direct evidence that BAL QSOs indeed have normal X-ray continua underlying their intrinsic absorption. Finally, marked variability between the ROSAT and ASCA observations of PG 1535+547 and PG 2112+059 suggests that the soft X-ray weak designation may be transient, and multi-epoch 0.1-10.0 KeV X-ray observations are required to constrain variability of the absorber and continuum.

  9. Clinical implications of the intrinsic molecular subtypes of breast cancer.

    PubMed

    Prat, Aleix; Pineda, Estela; Adamo, Barbara; Galván, Patricia; Fernández, Aranzazu; Gaba, Lydia; Díez, Marc; Viladot, Margarita; Arance, Ana; Muñoz, Montserrat

    2015-11-01

    Gene-expression profiling has had a considerable impact on our understanding of breast cancer biology. During the last 15 years, 5 intrinsic molecular subtypes of breast cancer (Luminal A, Luminal B, HER2-enriched, Basal-like and Claudin-low) have been identified and intensively studied. In this review, we will focus on the current and future clinical implications of the intrinsic molecular subtypes beyond the current pathological-based classification endorsed by the 2013 St. Gallen Consensus Recommendations. Within hormone receptor-positive and HER2-negative early breast cancer, the Luminal A and B subtypes predict 10-year outcome regardless of systemic treatment administered as well as residual risk of distant recurrence after 5 years of endocrine therapy. Within clinically HER2-positive disease, the 4 main intrinsic subtypes can be identified and dominate the biological and clinical phenotype. From a clinical perspective, patients with HER2+/HER2-enriched disease seem to benefit the most from neoadjuvant trastuzumab, or dual HER2 blockade with trastuzumab/lapatinib, in combination with chemotherapy, and patients with HER2+/Luminal A disease seem to have a relative better outcome compared to the other subtypes. Finally, within triple-negative breast cancer (TNBC), the Basal-like disease predominates (70-80%) and, from a biological perspective, should be considered a cancer-type by itself. Importantly, the distinction between Basal-like versus non-Basal-like within TNBC might predict survival following (neo)adjvuvant multi-agent chemotherapy, bevacizumab benefit in the neoadjuvant setting (CALGB40603), and docetaxel vs. carboplatin benefit in first-line metastatic disease (TNT study). Overall, this data suggests that intrinsic molecular profiling provides clinically relevant information beyond current pathology-based classifications.

  10. Extrinsic versus intrinsic hand muscle dominance in finger flexion.

    PubMed

    Al-Sukaini, A; Singh, H P; Dias, J J

    2016-05-01

    This study aims to identify the patterns of dominance of extrinsic or intrinsic muscles in finger flexion during initiation of finger curl and mid-finger flexion. We recorded 82 hands of healthy individuals (18-74 years) while flexing their fingers and tracked the finger joint angles of the little finger using video motion tracking. A total of 57 hands (69.5%) were classified as extrinsic dominant, where the finger flexion was initiated and maintained at proximal interphalangeal and distal interphalangeal joints. A total of 25 (30.5%) were classified as intrinsic dominant, where the finger flexion was initiated and maintained at the metacarpophalangeal joint. The distribution of age, sex, dominance, handedness and body mass index was similar in the two groups. This knowledge may allow clinicians to develop more efficient rehabilitation regimes, since intrinsic dominant individuals would not initiate extrinsic muscle contraction till later in finger flexion, and might therefore be allowed limited early active motion. For extrinsic dominant individuals, by contrast, initial contraction of extrinsic muscles would place increased stress on the tendon repair site if early motion were permitted. PMID:26744509

  11. In Search of the Neural Circuits of Intrinsic Motivation

    PubMed Central

    Kaplan, Frederic; Oudeyer, Pierre-Yves

    2007-01-01

    Children seem to acquire new know-how in a continuous and open-ended manner. In this paper, we hypothesize that an intrinsic motivation to progress in learning is at the origins of the remarkable structure of children's developmental trajectories. In this view, children engage in exploratory and playful activities for their own sake, not as steps toward other extrinsic goals. The central hypothesis of this paper is that intrinsically motivating activities correspond to expected decrease in prediction error. This motivation system pushes the infant to avoid both predictable and unpredictable situations in order to focus on the ones that are expected to maximize progress in learning. Based on a computational model and a series of robotic experiments, we show how this principle can lead to organized sequences of behavior of increasing complexity characteristic of several behavioral and developmental patterns observed in humans. We then discuss the putative circuitry underlying such an intrinsic motivation system in the brain and formulate two novel hypotheses. The first one is that tonic dopamine acts as a learning progress signal. The second is that this progress signal is directly computed through a hierarchy of microcortical circuits that act both as prediction and metaprediction systems. PMID:18982131

  12. Resonant Tunneling and Intrinsic Bistability in Twisted Graphene Structures

    NASA Astrophysics Data System (ADS)

    Rodriguez-Nieva, Joaquin; Dresselhaus, Mildred; Levitov, Leonid

    2015-03-01

    Bistable systems exhibit several distinct macroscopic states and can switch between them upon variation of some control parameter. Nonvolatile electronic systems that exhibit intrinsic bistability and fast switching times are desirable for low-power memory and logic. Experimental realizations of such systems, however, are scarce. We propose a novel mechanism for intrinsic bistability in van der Waals heterostructures formed by twisted graphene monolayers. Bistability in these systems originates from resonant tunneling and charge coupling between different graphene layers. These characteristics, governed by Dirac-like spectrum and Moiré periodicity of the tunneling Hamiltonian, allow multiple stable states in the sequential tunneling regime. In the bistability region, an intermediate electrically decoupled graphene layer can, for the same external bias, be either in a resonant or non-resonant state with respect to the top/bottom layer. Features of interest, such as resonant tunneling, negative differential resistance and bistability, are controlled by parameters easily accessible in experiments, namely the twist angle and interlayer conductances. We estimate the power required to retain this state, switching times, and assess volatility of such intrinsically bistable systems.

  13. Intrinsic geometry of a tidally deformed Kerr horizon

    NASA Astrophysics Data System (ADS)

    Poisson, Eric

    2013-04-01

    The intrinsic metric of a tidally deformed black-hole horizon can be presented in a coordinate system adapted to the horizon's null generators, with one coordinate acting as a running parameter along each generator, and two coordinates acting as constant generator labels. The metric is invariant under reparametrizations of the generators, and as such the horizon's intrinsic geometry is known to be gauge invariant. We consider a Kerr black hole deformed by a slowly-evolving external tidal field, and describe the intrinsic geometry of its event horizon in terms of the electric and magnetic tidal moments that characterize the tidal environment. When the black hole is slowly rotating, the horizon's geometry can be described in terms of a deviation from an otherwise spherical surface, and the deformation can be characterized by gauge invariant Love numbers. Some aspects of this tidal deformation have direct analogues in Newtonian physics. Some do not, and I will describe the similarities and differences between the tidal deformation of rotating black holes in general relativity and rotating fluid bodies in Newtonian physics.

  14. Intrinsic ethics regarding integrated assessment models for climate management.

    PubMed

    Schienke, Erich W; Baum, Seth D; Tuana, Nancy; Davis, Kenneth J; Keller, Klaus

    2011-09-01

    In this essay we develop and argue for the adoption of a more comprehensive model of research ethics than is included within current conceptions of responsible conduct of research (RCR). We argue that our model, which we label the ethical dimensions of scientific research (EDSR), is a more comprehensive approach to encouraging ethically responsible scientific research compared to the currently typically adopted approach in RCR training. This essay focuses on developing a pedagogical approach that enables scientists to better understand and appreciate one important component of this model, what we call intrinsic ethics. Intrinsic ethical issues arise when values and ethical assumptions are embedded within scientific findings and analytical methods. Through a close examination of a case study and its application in teaching, namely, evaluation of climate change integrated assessment models, this paper develops a method and case for including intrinsic ethics within research ethics training to provide scientists with a comprehensive understanding and appreciation of the critical role of values and ethical choices in the production of research outcomes. PMID:20532667

  15. Dimensionless size scaling of intrinsic rotation in DIII-D

    NASA Astrophysics Data System (ADS)

    deGrassie, J. S.; Solomon, W. M.; Rice, J. E.; Noterdaeme, J.-M.

    2016-08-01

    A dimensionless empirical scaling for intrinsic toroidal rotation is given: MA˜βNρ* , where MA is the toroidal velocity divided by the Alfvén velocity, βN is the usual normalized β value, and ρ* is the ion gyroradius divided by the minor radius. This scaling describes well experimental data from DIII-D and also some published data from C-Mod and JET. The velocity used in this scaling is in an outer location in minor radius, outside of the interior core and inside of the large gradient edge region in H-mode conditions. This scaling establishes the basic magnitude of the intrinsic toroidal rotation, and its relation to the rich variety of rotation profiles that can be realized for intrinsic conditions is discussed. This scaling has some similarities to existing dimensioned scalings, both the Rice scaling [J. E. Rice et al., Phys. Plasmas 7, 1825 (2000)] and the scaling of Parra et al. [Phys. Rev. Lett. 108, 095001 (2012)]. These relationships are described.

  16. Limits on the possible intrinsic magnetic field of Venus

    NASA Technical Reports Server (NTRS)

    Russell, C. T.; Elphic, R. C.; Slavin, J. A.

    1980-01-01

    Magnetic field measurements obtained by the Pioneer Venus orbiter at low altitudes in the solar wind wake region are examined for possible surface-correlated features and any possible intrinsic magnetic moment. The field variations observed in the wake do not resemble those expected for a solar wind interaction with even a weak intrinsic magnetic field. Little orbit-to-orbit persistence of features is found in the magnetic records. The magnetic field measurements in the wake are averaged in 10 deg x 10 deg bins to minimize the effects of external field sources. In these 37 bins, the average fields appear to be randomly oriented and consistent with zero mean in the region mapped. Using these 37 averaged vector fields, a maximum intrinsic magnetic dipole moment is obtained of 4.3 + or - 2.0 x 10 to the 21st G cu cm, approximately an order of magnitude less than previous estimates. It is noted that a more conservative estimate of the probable error of the mean is 5.5 x 10 to the 21st G cu cm. The Pioneer Venus measurements are thus consistent with zero planetary moment. The present measurements are found to be far below estimates made on the basis of angular momentum, the so-called magnetic Bode's law, and far below the dynamo scaling law of Busse.

  17. Intrinsic Valuation of Information in Decision Making under Uncertainty.

    PubMed

    Bennett, Daniel; Bode, Stefan; Brydevall, Maja; Warren, Hayley; Murawski, Carsten

    2016-07-01

    In a dynamic world, an accurate model of the environment is vital for survival, and agents ought regularly to seek out new information with which to update their world models. This aspect of behaviour is not captured well by classical theories of decision making, and the cognitive mechanisms of information seeking are poorly understood. In particular, it is not known whether information is valued only for its instrumental use, or whether humans also assign it a non-instrumental intrinsic value. To address this question, the present study assessed preference for non-instrumental information among 80 healthy participants in two experiments. Participants performed a novel information preference task in which they could choose to pay a monetary cost to receive advance information about the outcome of a monetary lottery. Importantly, acquiring information did not alter lottery outcome probabilities. We found that participants were willing to incur considerable monetary costs to acquire payoff-irrelevant information about the lottery outcome. This behaviour was well explained by a computational cognitive model in which information preference resulted from aversion to temporally prolonged uncertainty. These results strongly suggest that humans assign an intrinsic value to information in a manner inconsistent with normative accounts of decision making under uncertainty. This intrinsic value may be associated with adaptive behaviour in real-world environments by producing a bias towards exploratory and information-seeking behaviour.

  18. Characterizing the intrinsic correlations of scale-free networks

    NASA Astrophysics Data System (ADS)

    de Brito, J. B.; Sampaio Filho, C. I. N.; Moreira, A. A.; Andrade, J. S.

    2016-08-01

    When studying topological or dynamical properties of random scale-free networks, it is tacitly assumed that degree-degree correlations are not present. However, simple constraints, such as the absence of multiple edges and self-loops, can give rise to intrinsic correlations in these structures. In the same way that Fermionic correlations in thermodynamic systems are relevant only in the limit of low temperature, the intrinsic correlations in scale-free networks are relevant only when the extreme values for the degrees grow faster than the square root of the network size. In this situation, these correlations can significantly affect the dependence of the average degree of the nearest neighbors of a given vertex on this vertices degree. Here, we introduce an analytical approach that is capable to predict the functional form of this property. Moreover, our results indicate that random scale-free network models are not self-averaging, that is, the second moment of their degree distribution may vary orders of magnitude among different realizations. Finally, we argue that the intrinsic correlations investigated here may have profound impact on the critical properties of random scale-free networks.

  19. How the cosmic web induces intrinsic alignments of galaxies

    NASA Astrophysics Data System (ADS)

    Codis, S.; Dubois, Y.; Pichon, C.; Devriendt, J.; Slyz, A.

    2016-10-01

    Intrinsic alignments are believed to be a major source of systematics for future generation of weak gravitational lensing surveys like Euclid or LSST. Direct measurements of the alignment of the projected light distribution of galaxies in wide field imaging data seem to agree on a contamination at a level of a few per cent of the shear correlation functions, although the amplitude of the effect depends on the population of galaxies considered. Given this dependency, it is difficult to use dark matter-only simulations as the sole resource to predict and control intrinsic alignments. We report here estimates on the level of intrinsic alignment in the cosmological hydrodynamical simulation Horizon-AGN that could be a major source of systematic errors in weak gravitational lensing measurements. In particular, assuming that the spin of galaxies is a good proxy for their ellipticity, we show how those spins are spatially correlated and how they couple to the tidal field in which they are embedded. We will also present theoretical calculations that illustrate and qualitatively explain the observed signals.

  20. Effect of Intrinsic Ripples on Elasticity of the Graphene Monolayer.

    PubMed

    Lee, Seungjun

    2015-12-01

    The effect of intrinsic ripples on the mechanical response of the graphene monolayer is investigated under uniaxial loading using molecular dynamics (MD) simulations with a focus on nonlinear behavior at a small strain. The calculated stress-strain response shows a nonlinear relation through the entire range without constant slopes as a result of the competition between ripple softening and bond stretching hardening. For a small strain, entropic contribution is dominant due to intrinsic ripples, leading to elasticity softening. As the ripples flatten at increasing strain, the energetic term due to C-C bonds stretching competes with the entropic contribution, followed by energetic dominant deformation. Elasticity softening is enhanced at increased temperature as the ripple amplitude increases. The study shows that the intrinsic ripple of graphene affects elasticity. This result suggests that a change of ripple amplitudes due to various environmental conditions such as temperature, and substrate interactions can lead to a change of the mechanical properties of graphene. The understanding of the rippling effect on the mechanical behavior of 2D materials is useful for strain-based ripple manipulation for their engineering applications.

  1. Incremental learning of skill collections based on intrinsic motivation.

    PubMed

    Metzen, Jan H; Kirchner, Frank

    2013-01-01

    Life-long learning of reusable, versatile skills is a key prerequisite for embodied agents that act in a complex, dynamic environment and are faced with different tasks over their lifetime. We address the question of how an agent can learn useful skills efficiently during a developmental period, i.e., when no task is imposed on him and no external reward signal is provided. Learning of skills in a developmental period needs to be incremental and self-motivated. We propose a new incremental, task-independent skill discovery approach that is suited for continuous domains. Furthermore, the agent learns specific skills based on intrinsic motivation mechanisms that determine on which skills learning is focused at a given point in time. We evaluate the approach in a reinforcement learning setup in two continuous domains with complex dynamics. We show that an intrinsically motivated, skill learning agent outperforms an agent which learns task solutions from scratch. Furthermore, we compare different intrinsic motivation mechanisms and how efficiently they make use of the agent's developmental period.

  2. Role of 'intrinsic charm' in semileptonic B-meson decays

    SciTech Connect

    Breidenbach, C.; Feldmann, T.; Turczyk, S.; Mannel, T.

    2008-07-01

    We discuss the role of so-called 'intrinsic-charm' operators in semileptonic B-meson decays, which appear first at order 1/m{sub b}{sup 3} in the heavy quark expansion. We show by explicit calculation that - at scales {mu}{<=}m{sub c} - the contributions from 'intrinsic-charm' effects can be absorbed into short-distance coefficient functions multiplying, for instance, the Darwin term. Then, the only remnant of 'intrinsic charm' are logarithms of the form ln(m{sub c}{sup 2}/m{sub b}{sup 2}), which can be resummed by using renormalization-group techniques. As long as the dynamics at the charm-quark scale is perturbative, {alpha}{sub s}(m{sub c})<<1, this implies that no additional nonperturbative matrix elements aside from the Darwin and the spin-orbit term have to be introduced at order 1/m{sub b}{sup 3}. Hence, no sources for additional hadronic uncertainties have to be taken into account. Similar arguments may be made for higher orders in the 1/m{sub b} expansion.

  3. Intrinsic Multi-Scale Dynamic Behaviors of Complex Financial Systems.

    PubMed

    Ouyang, Fang-Yan; Zheng, Bo; Jiang, Xiong-Fei

    2015-01-01

    The empirical mode decomposition is applied to analyze the intrinsic multi-scale dynamic behaviors of complex financial systems. In this approach, the time series of the price returns of each stock is decomposed into a small number of intrinsic mode functions, which represent the price motion from high frequency to low frequency. These intrinsic mode functions are then grouped into three modes, i.e., the fast mode, medium mode and slow mode. The probability distribution of returns and auto-correlation of volatilities for the fast and medium modes exhibit similar behaviors as those of the full time series, i.e., these characteristics are rather robust in multi time scale. However, the cross-correlation between individual stocks and the return-volatility correlation are time scale dependent. The structure of business sectors is mainly governed by the fast mode when returns are sampled at a couple of days, while by the medium mode when returns are sampled at dozens of days. More importantly, the leverage and anti-leverage effects are dominated by the medium mode. PMID:26427063

  4. Integrating intrinsic mobility into unmanned ground vehicle systems

    NASA Astrophysics Data System (ADS)

    Brosinsky, Chris A.; Penzes, Steven G.; Buehler, Martin G.; Steeves, Carl

    2001-09-01

    The ability of an Unmanned Ground Vehicle (UGV) to successfully move about in its environment is enabled by the synergistic combination of perception, control and platform (mobility and utility). Vast effort is being expended on the former technologies but little demonstrable evidence has been produced to indicate that the latter (mobility/utility) has been considered as an integral part of the UGV systems level capability; a concept commonly referred to as intrinsic mobility. While past work described the rationale for hybrid locomotion, this paper aims to demonstrate that integrating intrinsic mobility into a UGV systems mobility element or 'vehicle' will be a key contributor to the magnitude of autonomy that the system can achieve. This paper serves to provide compelling evidence that 1) intrinsic mobility improvements provided by hybrid locomotion configurations offer the best generic mobility, that 2) strict attention must be placed on the optimization of both utility (inherent vehicle capabilities) and mobility and that 3) the establishment of measures of performance for unmanned vehicle mobility is an unmet and latent need.

  5. Relationship between placental traits and maternal intrinsic factors in sheep.

    PubMed

    Ocak, S; Ogun, S; Onder, H

    2013-06-01

    The relationship between maternal intrinsic factors and placental traits was investigated on three Southern Mediterranean breed of sheep; Cukurova Assaf (CA), Cukurova (C) and Cukurova Meat Sheep (CMS). The effect of parity and birth type were also considered in the study as a potential influencing factor. Our hypothesis was to show that while differences in placental traits between breed, parity and birth type affected lamb condition and survivability, its correlation to maternal intrinsic behavioral factors may also be a strong indicator. The study found breed related differences of maternal behavioral factors and also showed significant correlation of these behavioral patterns to various placental traits. It confirmed earlier findings that parity played a major role in the refinement of these behavioral patterns. Significant differences in birth weight (P<0.05), placental weight (P<0.05), number of cotyledons (P<0.01) and cotyledon length (P<0.05) was seen between breeds. Cotyledon weight (P<0.05), width (P<0.01) and length (P<0.05) were found to differ by parity. Breed and parity interaction significantly influenced cotyledon quantity. While we detected breed specific differences in relation to maternal intrinsic factors we also noticed significant variance within breeds to these behavioral patterns when linked to placental traits. Further study is required on the correlation between placental traits and postnatal behavior on not just the ewes but also on their lambs. This could have a significant bearing on how producers manage and maximize lamb survivability.

  6. Intrinsic Valuation of Information in Decision Making under Uncertainty

    PubMed Central

    Bode, Stefan; Brydevall, Maja; Murawski, Carsten

    2016-01-01

    In a dynamic world, an accurate model of the environment is vital for survival, and agents ought regularly to seek out new information with which to update their world models. This aspect of behaviour is not captured well by classical theories of decision making, and the cognitive mechanisms of information seeking are poorly understood. In particular, it is not known whether information is valued only for its instrumental use, or whether humans also assign it a non-instrumental intrinsic value. To address this question, the present study assessed preference for non-instrumental information among 80 healthy participants in two experiments. Participants performed a novel information preference task in which they could choose to pay a monetary cost to receive advance information about the outcome of a monetary lottery. Importantly, acquiring information did not alter lottery outcome probabilities. We found that participants were willing to incur considerable monetary costs to acquire payoff-irrelevant information about the lottery outcome. This behaviour was well explained by a computational cognitive model in which information preference resulted from aversion to temporally prolonged uncertainty. These results strongly suggest that humans assign an intrinsic value to information in a manner inconsistent with normative accounts of decision making under uncertainty. This intrinsic value may be associated with adaptive behaviour in real-world environments by producing a bias towards exploratory and information-seeking behaviour. PMID:27416034

  7. Effect of Intrinsic Ripples on Elasticity of the Graphene Monolayer

    NASA Astrophysics Data System (ADS)

    Lee, Seungjun

    2015-10-01

    The effect of intrinsic ripples on the mechanical response of the graphene monolayer is investigated under uniaxial loading using molecular dynamics (MD) simulations with a focus on nonlinear behavior at a small strain. The calculated stress-strain response shows a nonlinear relation through the entire range without constant slopes as a result of the competition between ripple softening and bond stretching hardening. For a small strain, entropic contribution is dominant due to intrinsic ripples, leading to elasticity softening. As the ripples flatten at increasing strain, the energetic term due to C-C bonds stretching competes with the entropic contribution, followed by energetic dominant deformation. Elasticity softening is enhanced at increased temperature as the ripple amplitude increases. The study shows that the intrinsic ripple of graphene affects elasticity. This result suggests that a change of ripple amplitudes due to various environmental conditions such as temperature, and substrate interactions can lead to a change of the mechanical properties of graphene. The understanding of the rippling effect on the mechanical behavior of 2D materials is useful for strain-based ripple manipulation for their engineering applications.

  8. An interatomic pair potential with tunable intrinsic ductility

    NASA Astrophysics Data System (ADS)

    Rajan, V. P.; Warner, D. H.; Curtin, W. A.

    2016-02-01

    A family of interatomic potentials is constructed for which the intrinsic ductility can be tuned systematically. Specifically, the elastic constants and critical energy release rate for Griffith cleavage, {{G}\\text{Ic}} , are held constant, while the critical energy release rate for dislocation emission, {{G}\\text{Ie}} , can be varied. This behavior is achieved by modifying a standard near-neighbor pair potential; the new potential is applicable to either 2D (hexagonal lattice) or 3D (FCC/HCP). Analytical expressions are provided for {{G}\\text{Ie}} and {{G}\\text{Ic}} , enabling a potential with a desired intrinsic ductility to be easily developed. Direct atomistic simulations are used to demonstrate that the new potentials control the intrinsic material ductility, i.e. crack tip dislocation emission versus brittle cleavage, under quasi-static loading. For the 2D potential, the mode I crack tip behavior can be tuned from brittle to ductile; for the 3D potential, such tuning is only possible for certain crack orientations. More generally, the new potentials are expected to be useful in a wide range of physical problems in which behavior is controlled by the ability of the material to nucleate dislocations, including problems involving crack tips, grain boundaries, contact and friction, and bi-material interfaces.

  9. A case study of the intrinsic bioremediation of petroleum hydrocarbons

    SciTech Connect

    Barker, G.W.; Raterman, K.T.; Fisher, J.B.; Corgan, J.M.

    1995-12-31

    Condensate liquids have been found to contaminate soil and groundwater at two gas production sites in the Denver Basin operated by Amoco Production Co. These sites have been closely monitored since July 1993 to determine whether intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurs at a sufficient rate and to an adequate endpoint to support a no-intervention decision. Groundwater monitoring and analysis of soil cores suggest that intrinsic bioremediation is occurring at these sites by multiple pathways including aerobic oxidation, Fe{sup 3+} reduction, and sulfate reduction. In laboratory experiments the addition of gas condensate hydrocarbons to saturated soil from the gas production site stimulated sulfate reduction under anaerobic and oxygen-limiting conditions, and nitrate and Fe{sup 3+} reduction under oxygen-limiting conditions, compared to biotic controls that lacked hydrocarbon and sterile controls. The sulfate reduction corresponded to a reduction in the amount of toluene relative to other hydrocarbons. These results confirmed that subsurface soils at the gas production site have the potential for intrinsic bioremediation of hydrocarbons.

  10. Intrinsic frame transport for a model of nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    Cozzini, S.; Rull, L. F.; Ciccotti, G.; Paolini, G. V.

    1997-02-01

    We present a computer simulation study of the dynamical properties of a nematic liquid crystal model. The diffusional motion of the nematic director is taken into account in our calculations in order to give a proper estimate of the transport coefficients. Differently from other groups we do not attempt to stabilize the director through rigid constraints or applied external fields. We instead define an intrinsic frame which moves along with the director at each step of the simulation. The transport coefficients computed in the intrinsic frame are then compared against the ones calculated in the fixed laboratory frame, to show the inadequacy of the latter for systems with less than 500 molecules. Using this general scheme on the Gay-Berne liquid crystal model, we evidence the natural motion of the director and attempt to quantify its intrinsic time scale and size dependence. Through extended simulations of systems of different size we calculate the diffusion and viscosity coefficients of this model and compare our results with values previously obtained with fixed director.

  11. Diffusion of Hydration Water around Intrinsically Disordered Proteins.

    PubMed

    Rani, Pooja; Biswas, Parbati

    2015-10-22

    Hydration water dynamics around globular proteins have attracted considerable attention in the past decades. This work investigates the hydration water dynamics around partially/fully intrinsically disordered proteins and compares it to that of the globular proteins via molecular dynamics simulations. The translational diffusion of the hydration water is examined by evaluating the mean-square displacement and the velocity autocorrelation function, while the rotational diffusion is probed through the dipole-dipole time correlation function. The results reveal that the translational and rotational motions of water molecules at the surface of intrinsically disordered proteins/regions are less restricted as compared to those around globular proteins/ordered regions, which is reflected in their higher diffusion coefficient and lower orientational relaxation time. The restricted mobility of hydration water in the vicinity of the protein leads to a sublinear diffusion in a heterogeneous interface. A positive correlation between the mean number of hydrogen bonds and the diffusion coefficient of hydration water implies higher mobility of water molecules at the surface of disordered proteins, which is due to their higher number of hydrogen bonds. Enhanced hydration water mobility around disordered proteins/regions is also related to their higher hydration capacity, low hydrophobicity, and increased internal protein motions. Thus, we generalize that the intrinsically disordered proteins/regions are associated with higher hydration water mobility as compared to globular protein/ordered regions, which may help to elucidate their varied functional specificity.

  12. Intrinsic Multi-Scale Dynamic Behaviors of Complex Financial Systems

    PubMed Central

    Ouyang, Fang-Yan; Zheng, Bo; Jiang, Xiong-Fei

    2015-01-01

    The empirical mode decomposition is applied to analyze the intrinsic multi-scale dynamic behaviors of complex financial systems. In this approach, the time series of the price returns of each stock is decomposed into a small number of intrinsic mode functions, which represent the price motion from high frequency to low frequency. These intrinsic mode functions are then grouped into three modes, i.e., the fast mode, medium mode and slow mode. The probability distribution of returns and auto-correlation of volatilities for the fast and medium modes exhibit similar behaviors as those of the full time series, i.e., these characteristics are rather robust in multi time scale. However, the cross-correlation between individual stocks and the return-volatility correlation are time scale dependent. The structure of business sectors is mainly governed by the fast mode when returns are sampled at a couple of days, while by the medium mode when returns are sampled at dozens of days. More importantly, the leverage and anti-leverage effects are dominated by the medium mode. PMID:26427063

  13. INTRINSIC DOSIMETRY: A POTENTIAL NEW TOOL FOR NUCLEAR FORENSICS INVESTIGATIONS

    SciTech Connect

    Clark, Richard A.; Miller, Steven D.; Robertson, Dave J.; Gregg, Roger A.; Murphy, Mark K.; Schwantes, Jon M.

    2010-08-11

    Thermoluminescence (TL) dosimetry was used to measure dose effects on the raw stock material of borosilicate container glass from different geographical locations. Effects were studied at times up to 60 days post-irradiation at doses from 0.15 to 20 Gy. The minimum detectable dose using this technique was estimated to be 0.15 Gy which is roughly equivalent to a 24 hr irradiation 1 cm from a 50 ng source of 60Co. Two peaks were identified in the TL glow curve, a relatively unstable peak around 125°C and a more stable peak around 225°C. Differences in TL glow curve shape and intensity were also observed for the glasses from different geographical origins. We investigate radiation induced defects in glass to further develop the technique of intrinsic dosimetry–the measurement of the total absorbed dose received by the walls of a container holding radioactive material. Intrinsic dosimetry is intended to be used as an interrogation tool to provide enhanced pathway information on interdicted or newly discovered waste containers of unknown origin or history by considering the total absorbed dose received by a container in tandem with the physical characteristics of the radioactive material housed within that container. One hypothetical scenario is presented to illustrate the application of intrinsic dosimetry to waste management and nuclear forensics.

  14. Intrinsic Valuation of Information in Decision Making under Uncertainty.

    PubMed

    Bennett, Daniel; Bode, Stefan; Brydevall, Maja; Warren, Hayley; Murawski, Carsten

    2016-07-01

    In a dynamic world, an accurate model of the environment is vital for survival, and agents ought regularly to seek out new information with which to update their world models. This aspect of behaviour is not captured well by classical theories of decision making, and the cognitive mechanisms of information seeking are poorly understood. In particular, it is not known whether information is valued only for its instrumental use, or whether humans also assign it a non-instrumental intrinsic value. To address this question, the present study assessed preference for non-instrumental information among 80 healthy participants in two experiments. Participants performed a novel information preference task in which they could choose to pay a monetary cost to receive advance information about the outcome of a monetary lottery. Importantly, acquiring information did not alter lottery outcome probabilities. We found that participants were willing to incur considerable monetary costs to acquire payoff-irrelevant information about the lottery outcome. This behaviour was well explained by a computational cognitive model in which information preference resulted from aversion to temporally prolonged uncertainty. These results strongly suggest that humans assign an intrinsic value to information in a manner inconsistent with normative accounts of decision making under uncertainty. This intrinsic value may be associated with adaptive behaviour in real-world environments by producing a bias towards exploratory and information-seeking behaviour. PMID:27416034

  15. Anomalous Spectral Types and Intrinsic Colors of Young Stars

    NASA Astrophysics Data System (ADS)

    Pecaut, Mark J.

    2016-01-01

    We highlight differences in spectral types and intrinsic colors observed in pre-main sequence (pre-MS) stars. Spectral types of pre-MS stars are wavelength-dependent, with near-infrared spectra being 3-5 spectral sub-classes later than the spectral types determined from optical spectra. In addition, the intrinsic colors of young stars differ from that of main-sequence stars at a given spectral type. We caution observers to adopt optical spectral types over near-infrared types, since Hertzsprung-Russell (H-R) diagram positions derived from optical spectral types provide consistency between dynamical masses and theoretical evolutionary tracks. We also urge observers to deredden pre-MS stars with tabulations of intrinsic colors specifically constructed for young stars, since their unreddened colors differ from that of main sequence dwarfs. Otherwise, V-band extinctions as much as ~0.6 mag erroneously higher than the true extinction may result, which would introduce systematic errors in the H-R diagram positions and thus bias the inferred ages.

  16. Identifying intrinsic constituents of focus through ``imitation via restoration.''

    NASA Astrophysics Data System (ADS)

    Xu, Yi; Xu, Ching X.; Sun, Xuejing

    2003-04-01

    In this study we test the hypothesis that although certain parts of an observed intonation may seem dispensable in perception tests, they nevertheless are consistently produced by speakers. We refer to all consistently produced parts of an intonation as its ``intrinsic constituents.'' To identify the intrinsic constituents, we developed an experimental paradigm called ``imitation via restoration.'' In this paradigm, the intonation under scrutiny is first recorded by a native speaker. Then words carrying a potential constituent of the intonation are replaced by a loud noise. During the experiment, the sentence containing the replacement noise is presented to the subjects together with the text. The subjects' task is to repeat the sentence in exactly the same way as they hear it. The consistency with which subjects restore the missing parts of the target intonation would therefore provide a reasonable indication as to which of them are truly intrinsic to the intonation. Our first such experiment was conducted on determining whether focus consists of only on-focus pitch range expansion or it also involves obligatory post-focus pitch range suppression. Eight native speakers of Beijing Mandarin participated as subjects. Preliminary results have provided supporting evidence for the dual-component hypothesis.

  17. Incremental learning of skill collections based on intrinsic motivation

    PubMed Central

    Metzen, Jan H.; Kirchner, Frank

    2013-01-01

    Life-long learning of reusable, versatile skills is a key prerequisite for embodied agents that act in a complex, dynamic environment and are faced with different tasks over their lifetime. We address the question of how an agent can learn useful skills efficiently during a developmental period, i.e., when no task is imposed on him and no external reward signal is provided. Learning of skills in a developmental period needs to be incremental and self-motivated. We propose a new incremental, task-independent skill discovery approach that is suited for continuous domains. Furthermore, the agent learns specific skills based on intrinsic motivation mechanisms that determine on which skills learning is focused at a given point in time. We evaluate the approach in a reinforcement learning setup in two continuous domains with complex dynamics. We show that an intrinsically motivated, skill learning agent outperforms an agent which learns task solutions from scratch. Furthermore, we compare different intrinsic motivation mechanisms and how efficiently they make use of the agent's developmental period. PMID:23898265

  18. Intrinsic ethics regarding integrated assessment models for climate management.

    PubMed

    Schienke, Erich W; Baum, Seth D; Tuana, Nancy; Davis, Kenneth J; Keller, Klaus

    2011-09-01

    In this essay we develop and argue for the adoption of a more comprehensive model of research ethics than is included within current conceptions of responsible conduct of research (RCR). We argue that our model, which we label the ethical dimensions of scientific research (EDSR), is a more comprehensive approach to encouraging ethically responsible scientific research compared to the currently typically adopted approach in RCR training. This essay focuses on developing a pedagogical approach that enables scientists to better understand and appreciate one important component of this model, what we call intrinsic ethics. Intrinsic ethical issues arise when values and ethical assumptions are embedded within scientific findings and analytical methods. Through a close examination of a case study and its application in teaching, namely, evaluation of climate change integrated assessment models, this paper develops a method and case for including intrinsic ethics within research ethics training to provide scientists with a comprehensive understanding and appreciation of the critical role of values and ethical choices in the production of research outcomes.

  19. Intrinsic bioremediation of gas condensate hydrocarbons - field and laboratory investigations

    SciTech Connect

    Barker, G.W.; Raterman, K.T.; Fisher, J.B.; Corgan, J.M.

    1995-12-31

    Condensate liquids have been found to contaminate soil and groundwater at two gas production sites in the Denver Basin operated by Amoco Production Co. These sites have been closely monitored since July, 1993, to determine whether intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurs at a sufficient rate and to an adequate endpoint to support a no-intervention decision. Groundwater monitoring and analysis of soil cores suggest that intrinsic bioremediation is occurring at these sites by multiple pathways including aerobic oxidation, Fe(III) reduction and sulfate reduction. In laboratory experiments the addition of gas condensate hydrocarbons to saturated soil from the gas production site stimulated sulfate reduction under anaerobic and oxygen-limiting conditions, and nitrate and Fe(III) reduction under oxygen-limiting conditions, compared to biotic controls that lacked hydrocarbon and sterile controls. The sulfate reduction corresponded to a reduction in the amount of toluene relative to other hydrocarbons. These results confirmed that subsurface soils at the gas production site have the potential for intrinsic bioremediation of hydrocarbons.

  20. Optimizing potential energy functions for maximal intrinsic hyperpolarizability

    SciTech Connect

    Zhou Juefei; Szafruga, Urszula B.; Kuzyk, Mark G.; Watkins, David S.

    2007-11-15

    We use numerical optimization to study the properties of (1) the class of one-dimensional potential energy functions and (2) systems of point nuclei in two dimensions that yield the largest intrinsic hyperpolarizabilities, which we find to be within 30% of the fundamental limit. In all cases, we use a one-electron model. It is found that a broad range of optimized potentials, each of very different character, yield the same intrinsic hyperpolarizability ceiling of 0.709. Furthermore, all optimized potential energy functions share common features such as (1) the value of the normalized transition dipole moment to the dominant state, which forces the hyperpolarizability to be dominated by only two excited states and (2) the energy ratio between the two dominant states. All optimized potentials are found to obey the three-level ansatz to within about 1%. Many of these potential energy functions may be implementable in multiple quantum well structures. The subset of potentials with undulations reaffirm that modulation of conjugation may be an approach for making better organic molecules, though there appear to be many others. Additionally, our results suggest that one-dimensional molecules may have larger diagonal intrinsic hyperpolarizability {beta}{sub xxx}{sup int} than higher-dimensional systems.

  1. Is the (3 + 1)-d nature of the universe a thermodynamic necessity?

    NASA Astrophysics Data System (ADS)

    Gonzalez-Ayala, Julian; Cordero, Rubén; Angulo-Brown, F.

    2016-02-01

    It is well established that at early times, long before the time of radiation-matter density equality, the universe could have been well described by a spatially flat, radiation only model. In this article we consider the whole primeval universe, as a first approach, as a black-body radiation system in an n-dimensional Euclidean space. We propose that the (3 + 1)-dimensional nature of the universe could be the result of a thermodynamic selection principle stemming from the second law of thermodynamics. In regard to the three spatial dimensions we suggest that they were chosen by means of the minimization of the Helmholtz free energy per hypervolume unit following possibly a kind of broken symmetry process, while the time dimension, as is well known, is related with the principle of increment of entropy for closed systems: the so-called arrow of time.

  2. Open University

    SciTech Connect

    2006-01-18

    Michel Pentz est née en Afrique du Sud et venu au Cern en 1957 comme physicien et président de l'associaion du personnel. Il est également fondateur du mouvement Antiapartheid de Genève et a participé à la fondation de l'Open University en Grande-Bretagne. Il nous parle des contextes pédagogiques, culturels et nationaux dans lesquels la méthode peut s'appliquer.

  3. Open University

    ScienceCinema

    None

    2016-07-12

    Michel Pentz est née en Afrique du Sud et venu au Cern en 1957 comme physicien et président de l'associaion du personnel. Il est également fondateur du mouvement Antiapartheid de Genève et a participé à la fondation de l'Open University en Grande-Bretagne. Il nous parle des contextes pédagogiques, culturels et nationaux dans lesquels la méthode peut s'appliquer.

  4. Downscaling Smooth Tomographic Models: Separating Intrinsic and Apparent Anisotropy

    NASA Astrophysics Data System (ADS)

    Bodin, Thomas; Capdeville, Yann; Romanowicz, Barbara

    2016-04-01

    In recent years, a number of tomographic models based on full waveform inversion have been published. Due to computational constraints, the fitted waveforms are low pass filtered, which results in an inability to map features smaller than half the shortest wavelength. However, these tomographic images are not a simple spatial average of the true model, but rather an effective, apparent, or equivalent model that provides a similar 'long-wave' data fit. For example, it can be shown that a series of horizontal isotropic layers will be seen by a 'long wave' as a smooth anisotropic medium. In this way, the observed anisotropy in tomographic models is a combination of intrinsic anisotropy produced by lattice-preferred orientation (LPO) of minerals, and apparent anisotropy resulting from the incapacity of mapping discontinuities. Interpretations of observed anisotropy (e.g. in terms of mantle flow) requires therefore the separation of its intrinsic and apparent components. The "up-scaling" relations that link elastic properties of a rapidly varying medium to elastic properties of the effective medium as seen by long waves are strongly non-linear and their inverse highly non-unique. That is, a smooth homogenized effective model is equivalent to a large number of models with discontinuities. In the 1D case, Capdeville et al (GJI, 2013) recently showed that a tomographic model which results from the inversion of low pass filtered waveforms is an homogenized model, i.e. the same as the model computed by upscaling the true model. Here we propose a stochastic method to sample the ensemble of layered models equivalent to a given tomographic profile. We use a transdimensional formulation where the number of layers is variable. Furthermore, each layer may be either isotropic (1 parameter) or intrinsically anisotropic (2 parameters). The parsimonious character of the Bayesian inversion gives preference to models with the least number of parameters (i.e. least number of layers, and

  5. Evolution of Intrinsic Scatter in the SFR-Stellar Mass Correlation at 0.5

    NASA Astrophysics Data System (ADS)

    Kurczynski, Peter; Gawiser, Eric J.; Acquaviva, Viviana; Rafelski, Marc; Teplitz, Harry I.; UVUDF Team, CANDELS Team

    2016-01-01

    We present observations of intrinsic scatter in the Star Formation Rate (SFR) - Stellar Mass (M*) correlation in the redshift range 0.5 < z < 3.0 and in the mass range 10^7 < M* < 10^11 Msun. We utilize photometry from the Hubble Ultradeep Field from the UDF12 and UVUDF campaigns and CANDELS/GOODS-S. By utilizing the exceptionally deep UDF photometry (e.g. F160W 29.9 AB, 5 sigma depth) and fitting the corresponding SEDs, we extend the SFR-M* correlation by a factor of 10-100X lower in M*. We detect galaxies down to M* approx 10^7 Msun, comparable to dwarf galaxies in the local universe. We find that the intrinsic scatter is relatively constant across the mass range, and in conflict with theoretical predictions, we do not find evidence for markedly increased scatter at low mass. We find a moderate increase in total and intrinsic scatter with time across the epoch of peak cosmic star formation. These findings are consistent with gradual assembly of stellar mass in galaxies as low as 10^7 Msun and star formation that is increasingly stochastic with cosmic time.

  6. DETERMINATION OF THE INTRINSIC LUMINOSITY TIME CORRELATION IN THE X-RAY AFTERGLOWS OF GAMMA-RAY BURSTS

    SciTech Connect

    Dainotti, Maria Giovanna; Petrosian, Vahe'; Singal, Jack; Ostrowski, Michal E-mail: vahep@stanford.edu E-mail: dainotti@oa.uj.edu.pl

    2013-09-10

    Gamma-ray bursts (GRBs), which have been observed up to redshifts z Almost-Equal-To 9.5, can be good probes of the early universe and have the potential to test cosmological models. Dainotti's analysis of GRB Swift afterglow light curves with known redshifts and a definite X-ray plateau shows an anti-correlation between the rest-frame time when the plateau ends (the plateau end time) and the calculated luminosity at that time (or approximately an anti-correlation between plateau duration and luminosity). Here, we present an update of this correlation with a larger data sample of 101 GRBs with good light curves. Since some of this correlation could result from the redshift dependences of these intrinsic parameters, namely, their cosmological evolution, we use the Efron-Petrosian method to reveal the intrinsic nature of this correlation. We find that a substantial part of the correlation is intrinsic and describe how we recover it and how this can be used to constrain physical models of the plateau emission, the origin of which is still unknown. The present result could help to clarify the debated nature of the plateau emission.

  7. The unfoldomics decade: an update on intrinsically disordered proteins

    PubMed Central

    Dunker, A Keith; Oldfield, Christopher J; Meng, Jingwei; Romero, Pedro; Yang, Jack Y; Chen, Jessica Walton; Vacic, Vladimir; Obradovic, Zoran; Uversky, Vladimir N

    2008-01-01

    Background Our first predictor of protein disorder was published just over a decade ago in the Proceedings of the IEEE International Conference on Neural Networks (Romero P, Obradovic Z, Kissinger C, Villafranca JE, Dunker AK (1997) Identifying disordered regions in proteins from amino acid sequence. Proceedings of the IEEE International Conference on Neural Networks, 1: 90–95). By now more than twenty other laboratory groups have joined the efforts to improve the prediction of protein disorder. While the various prediction methodologies used for protein intrinsic disorder resemble those methodologies used for secondary structure prediction, the two types of structures are entirely different. For example, the two structural classes have very different dynamic properties, with the irregular secondary structure class being much less mobile than the disorder class. The prediction of secondary structure has been useful. On the other hand, the prediction of intrinsic disorder has been revolutionary, leading to major modifications of the more than 100 year-old views relating protein structure and function. Experimentalists have been providing evidence over many decades that some proteins lack fixed structure or are disordered (or unfolded) under physiological conditions. In addition, experimentalists are also showing that, for many proteins, their functions depend on the unstructured rather than structured state; such results are in marked contrast to the greater than hundred year old views such as the lock and key hypothesis. Despite extensive data on many important examples, including disease-associated proteins, the importance of disorder for protein function has been largely ignored. Indeed, to our knowledge, current biochemistry books don't present even one acknowledged example of a disorder-dependent function, even though some reports of disorder-dependent functions are more than 50 years old. The results from genome-wide predictions of intrinsic disorder and the

  8. Role of intrinsic width in fragment momentum distributions in heavy ion collisions.

    PubMed

    Tripathi, R K; Townsend, L W; Khan, F

    1994-04-01

    It is demonstrated that the intrinsic widths incorporating correlations in conjunction with dynamical contributions give better agreement with experiments for collisions in the energy range of 200A MeV to 2A GeV than using only intrinsic widths without correlations. The sensitivity of the intrinsic width decreases with increasing projectile mass. A simple recipe for calculating intrinsic width with correlations is presented.

  9. Increasing burden of urinary tract infections due to intrinsic colistin-resistant bacteria in hospitals in Marseille, France.

    PubMed

    Abat, Cédric; Desboves, Guillaume; Olaitan, Abiola Olumuyiwa; Chaudet, Hervé; Roattino, Nicole; Fournier, Pierre-Edouard; Colson, Philippe; Raoult, Didier; Rolain, Jean-Marc

    2015-02-01

    The emergence of multidrug-resistant (MDR) Gram-negative bacteria has become a major public health problem, eliciting renewed interest in colistin, an old antibiotic that is now routinely used to treat MDR bacterial infections. Here we investigated whether colistin use has affected the prevalence of infections due to intrinsic colistin-resistant bacteria (CRB) in university hospitals in Marseille (France) over a 5-year period. All data from patients infected by intrinsic CRB were compiled from January 2009 to December 2013. Escherichia coli infections were used for comparison. Colistin consumption data were also collected from pharmacy records from 2008 to 2013. A total of 4847 intrinsic CRB infections, including 3150 Proteus spp., 847 Morganella spp., 704 Serratia spp. and 146 Providencia spp., were collected between 2009 and 2013. During this period, the annual incidence rate of hospital-acquired CRB infections increased from 220 per 1000 patients to 230 per 1000 patients and that of community-acquired CRB infections increased from 100 per 1000 patients to 140 per 1000 patients. In parallel, colistin consumption increased 2.2-fold from 2008 to 2013, mainly because of an increase in the use of colistin aerosol forms (from 50 unitary doses to 2926 unitary doses; P<10(-5)) that was significantly correlated with an increase in the number of patients positive for CRB admitted to ICUs and units of long-term care between 2009 and 2013 (r=0.91; P=0.03). The global rise in infections due to intrinsic CRB is worrying and surveillance is warranted to better characterise this intriguing epidemiological change. PMID:25497970

  10. Increasing burden of urinary tract infections due to intrinsic colistin-resistant bacteria in hospitals in Marseille, France.

    PubMed

    Abat, Cédric; Desboves, Guillaume; Olaitan, Abiola Olumuyiwa; Chaudet, Hervé; Roattino, Nicole; Fournier, Pierre-Edouard; Colson, Philippe; Raoult, Didier; Rolain, Jean-Marc

    2015-02-01

    The emergence of multidrug-resistant (MDR) Gram-negative bacteria has become a major public health problem, eliciting renewed interest in colistin, an old antibiotic that is now routinely used to treat MDR bacterial infections. Here we investigated whether colistin use has affected the prevalence of infections due to intrinsic colistin-resistant bacteria (CRB) in university hospitals in Marseille (France) over a 5-year period. All data from patients infected by intrinsic CRB were compiled from January 2009 to December 2013. Escherichia coli infections were used for comparison. Colistin consumption data were also collected from pharmacy records from 2008 to 2013. A total of 4847 intrinsic CRB infections, including 3150 Proteus spp., 847 Morganella spp., 704 Serratia spp. and 146 Providencia spp., were collected between 2009 and 2013. During this period, the annual incidence rate of hospital-acquired CRB infections increased from 220 per 1000 patients to 230 per 1000 patients and that of community-acquired CRB infections increased from 100 per 1000 patients to 140 per 1000 patients. In parallel, colistin consumption increased 2.2-fold from 2008 to 2013, mainly because of an increase in the use of colistin aerosol forms (from 50 unitary doses to 2926 unitary doses; P<10(-5)) that was significantly correlated with an increase in the number of patients positive for CRB admitted to ICUs and units of long-term care between 2009 and 2013 (r=0.91; P=0.03). The global rise in infections due to intrinsic CRB is worrying and surveillance is warranted to better characterise this intriguing epidemiological change.

  11. Purdue University

    SciTech Connect

    Daly, P.; Grabowski, Z.; Mayer, R.H.

    1995-08-01

    The Purdue University group, including several thesis students, is working on a measurement of high-spin nuclear states at ATLAS. They use in-beam gamma-ray techniques to investigate several aspects of nuclear structure at high spin, testing the validity of shell-model calculations for high-spin-yrast states near Z = 50. The nuclei are produced via deep inelastic reactions, rather than with the more conventional fusion reactions. This technique allows the study of neutron-rich nuclei that cannot be studied by other means. The group is studying proton-rich nuclei with N{approximately}82 using the FMA and an electron spectrometer. Furthermore, D. Nisius is a Ph.D. student, resident at ANL, performing his thesis work under the supervision of R.V.F. Janssens.

  12. Trait Intrinsic and Extrinsic Motivations, Academic Performance, and Creativity in Hong Kong College Students.

    ERIC Educational Resources Information Center

    Moneta, Giovanni B.; Siu, Christy M. Y.

    2002-01-01

    Examines the effects of trait intrinsic and extrinsic motivations, measured by the Work Preference Inventory, on creativity and academic performance. In an experimental creative writing task, intrinsic motivation correlated with creativity. In a follow-up study, intrinsic motivation correlated negatively with year-1 GPA, whereas extrinsic…

  13. Intrinsic Motivation and the Acquisition and Maintenance of Four Experiential States.

    ERIC Educational Resources Information Center

    Reeve, Johnmarshall

    1989-01-01

    Examines the effects of competence, self-determination, excitement, and affiliativeness on intrinsic motivation. Showed that maintainers of each experiential state had higher levels of intrinsic motivation than nonmaintainers, substantiating that experiential states function as maintaining stimuli to sustain intrinsic motivation. Suggests that…

  14. The Carnegie Supernova Project: Intrinsic colors of type Ia supernovae

    SciTech Connect

    Burns, Christopher R.; Persson, S. E.; Freedman, Wendy L.; Madore, Barry F.; Stritzinger, Maximilian; Contreras, Carlos; Phillips, M. M.; Hsiao, E. Y.; Boldt, Luis; Campillay, Abdo; Castellón, Sergio; Morrell, Nidia; Salgado, Francisco; Folatelli, Gaston; Suntzeff, Nicholas B.

    2014-07-01

    We present an updated analysis of the intrinsic colors of Type Ia supernova (SNe Ia) using the latest data release of the Carnegie Supernova Project. We introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find that these peculiar types can be seen as extensions to the population of 'normal' SNe Ia. With a larger number of objects, an updated fit to the Lira relation is presented along with evidence for a dependence on the late-time slope of the B – V light-curves with stretch and color. Using the full wavelength range from u to H band, we place constraints on the reddening law for the sample as a whole and also for individual events/hosts based solely on the observed colors. The photometric data continue to favor low values of R{sub V} , though with large variations from event to event, indicating an intrinsic distribution. We confirm the findings of other groups that there appears to be a correlation between the derived reddening law, R{sub V} , and the color excess, E(B – V), such that larger E(B – V) tends to favor lower R{sub V} . The intrinsic u-band colors show a relatively large scatter that cannot be explained by variations in R{sub V} or by the Goobar power-law for circumstellar dust, but rather is correlated with spectroscopic features of the supernova and is therefore likely due to metallicity effects.

  15. The intrinsic shape of galaxies in SDSS/Galaxy Zoo

    NASA Astrophysics Data System (ADS)

    Rodríguez, Silvio; Padilla, Nelson D.

    2013-09-01

    By modelling the axis ratio distribution of Sloan Digital Sky Survey (SDSS) Data Release 8 galaxies, we find the intrinsic 3D shapes of spirals and ellipticals. We use morphological information from the Galaxy Zoo project and assume a non-parametric distribution intrinsic of shapes, while taking into account dust extinction. We measure the dust extinction of the full sample of spiral galaxies and find a smaller value than previous estimations, with an edge-on extinction of E_0 = 0.284^{+0.015}_{-0.026} in the SDSS r band. We also find that the distribution of minor to major axis ratio has a mean value of 0.267 ± 0.009, slightly larger than previous estimates mainly due to the lower extinction used; the same affects the circularity of galactic discs, which are found to be less round in shape than in previous studies, with a mean ellipticity of 0.215 ± 0.013. For elliptical galaxies, we find that the minor to major axis ratio, with a mean value of 0.584 ± 0.006, is larger than previous estimations due to the removal of spiral interlopers present in samples with morphological information from photometric profiles. These interlopers are removed when selecting ellipticals using Galaxy Zoo data. We find that the intrinsic shapes of galaxies and their dust extinction vary with absolute magnitude, colour and physical size. We find that bright elliptical galaxies are more spherical than faint ones, a trend that is also present with galaxy size, and that there is no dependence of elliptical galaxy shape with colour. For spiral galaxies, we find that the reddest ones have higher dust extinction as expected, due to the fact that this reddening is mainly due to dust. We also find that the thickness of discs increases with luminosity and size, and that brighter, smaller and redder galaxies have less round discs.

  16. Robust active binocular vision through intrinsically motivated learning.

    PubMed

    Lonini, Luca; Forestier, Sébastien; Teulière, Céline; Zhao, Yu; Shi, Bertram E; Triesch, Jochen

    2013-01-01

    The efficient coding hypothesis posits that sensory systems of animals strive to encode sensory signals efficiently by taking into account the redundancies in them. This principle has been very successful in explaining response properties of visual sensory neurons as adaptations to the statistics of natural images. Recently, we have begun to extend the efficient coding hypothesis to active perception through a form of intrinsically motivated learning: a sensory model learns an efficient code for the sensory signals while a reinforcement learner generates movements of the sense organs to improve the encoding of the signals. To this end, it receives an intrinsically generated reinforcement signal indicating how well the sensory model encodes the data. This approach has been tested in the context of binocular vison, leading to the autonomous development of disparity tuning and vergence control. Here we systematically investigate the robustness of the new approach in the context of a binocular vision system implemented on a robot. Robustness is an important aspect that reflects the ability of the system to deal with unmodeled disturbances or events, such as insults to the system that displace the stereo cameras. To demonstrate the robustness of our method and its ability to self-calibrate, we introduce various perturbations and test if and how the system recovers from them. We find that (1) the system can fully recover from a perturbation that can be compensated through the system's motor degrees of freedom, (2) performance degrades gracefully if the system cannot use its motor degrees of freedom to compensate for the perturbation, and (3) recovery from a perturbation is improved if both the sensory encoding and the behavior policy can adapt to the perturbation. Overall, this work demonstrates that our intrinsically motivated learning approach for efficient coding in active perception gives rise to a self-calibrating perceptual system of high robustness. PMID:24223552

  17. Robust active binocular vision through intrinsically motivated learning.

    PubMed

    Lonini, Luca; Forestier, Sébastien; Teulière, Céline; Zhao, Yu; Shi, Bertram E; Triesch, Jochen

    2013-01-01

    The efficient coding hypothesis posits that sensory systems of animals strive to encode sensory signals efficiently by taking into account the redundancies in them. This principle has been very successful in explaining response properties of visual sensory neurons as adaptations to the statistics of natural images. Recently, we have begun to extend the efficient coding hypothesis to active perception through a form of intrinsically motivated learning: a sensory model learns an efficient code for the sensory signals while a reinforcement learner generates movements of the sense organs to improve the encoding of the signals. To this end, it receives an intrinsically generated reinforcement signal indicating how well the sensory model encodes the data. This approach has been tested in the context of binocular vison, leading to the autonomous development of disparity tuning and vergence control. Here we systematically investigate the robustness of the new approach in the context of a binocular vision system implemented on a robot. Robustness is an important aspect that reflects the ability of the system to deal with unmodeled disturbances or events, such as insults to the system that displace the stereo cameras. To demonstrate the robustness of our method and its ability to self-calibrate, we introduce various perturbations and test if and how the system recovers from them. We find that (1) the system can fully recover from a perturbation that can be compensated through the system's motor degrees of freedom, (2) performance degrades gracefully if the system cannot use its motor degrees of freedom to compensate for the perturbation, and (3) recovery from a perturbation is improved if both the sensory encoding and the behavior policy can adapt to the perturbation. Overall, this work demonstrates that our intrinsically motivated learning approach for efficient coding in active perception gives rise to a self-calibrating perceptual system of high robustness.

  18. Intrinsic host restriction factors of human cytomegalovirus replication and mechanisms of viral escape.

    PubMed

    Landolfo, Santo; De Andrea, Marco; Dell'Oste, Valentina; Gugliesi, Francesca

    2016-08-12

    Before a pathogen even enters a cell, intrinsic immune defenses are active. This first-line defense is mediated by a variety of constitutively expressed cell proteins collectively termed "restriction factors" (RFs), and they form a vital element of the immune response to virus infections. Over time, however, viruses have evolved in a variety ways so that they are able to overcome these RF defenses via mechanisms that are specific for each virus. This review provides a summary of the universal characteristics of RFs, and goes on to focus on the strategies employed by some of the most important RFs in their attempt to control human cytomegalovirus (HCMV) infection. This is followed by a discussion of the counter-restriction mechanisms evolved by viruses to circumvent the host cell's intrinsic immune defenses. RFs include nuclear proteins IFN-γ inducible protein 16 (IFI16) (a Pyrin/HIN domain protein), Sp100, promyelocytic leukemia, and hDaxx; the latter three being the keys elements of nuclear domain 10 (ND10). IFI16 inhibits the synthesis of virus DNA by down-regulating UL54 transcription - a gene encoding a CMV DNA polymerase; in response, the virus antagonizes IFI16 via a process involving viral proteins UL97 and pp65 (pUL83), which results in the mislocalizing of IFI16 into the cytoplasm. In contrast, viral regulatory proteins, including pp71 and IE1, seek to modify or disrupt the ND10 proteins and thus block or reverse their inhibitory effects upon virus replication. All in all, detailed knowledge of these HCMV counter-restriction mechanisms will be fundamental for the future development of new strategies for combating HCMV infection and for identifying novel therapeutic agents. PMID:27563536

  19. Intrinsic host restriction factors of human cytomegalovirus replication and mechanisms of viral escape

    PubMed Central

    Landolfo, Santo; De Andrea, Marco; Dell’Oste, Valentina; Gugliesi, Francesca

    2016-01-01

    Before a pathogen even enters a cell, intrinsic immune defenses are active. This first-line defense is mediated by a variety of constitutively expressed cell proteins collectively termed “restriction factors” (RFs), and they form a vital element of the immune response to virus infections. Over time, however, viruses have evolved in a variety ways so that they are able to overcome these RF defenses via mechanisms that are specific for each virus. This review provides a summary of the universal characteristics of RFs, and goes on to focus on the strategies employed by some of the most important RFs in their attempt to control human cytomegalovirus (HCMV) infection. This is followed by a discussion of the counter-restriction mechanisms evolved by viruses to circumvent the host cell’s intrinsic immune defenses. RFs include nuclear proteins IFN-γ inducible protein 16 (IFI16) (a Pyrin/HIN domain protein), Sp100, promyelocytic leukemia, and hDaxx; the latter three being the keys elements of nuclear domain 10 (ND10). IFI16 inhibits the synthesis of virus DNA by down-regulating UL54 transcription - a gene encoding a CMV DNA polymerase; in response, the virus antagonizes IFI16 via a process involving viral proteins UL97 and pp65 (pUL83), which results in the mislocalizing of IFI16 into the cytoplasm. In contrast, viral regulatory proteins, including pp71 and IE1, seek to modify or disrupt the ND10 proteins and thus block or reverse their inhibitory effects upon virus replication. All in all, detailed knowledge of these HCMV counter-restriction mechanisms will be fundamental for the future development of new strategies for combating HCMV infection and for identifying novel therapeutic agents. PMID:27563536

  20. Quantum phases in intrinsic Josephson junctions: Quantum magnetism analogy

    NASA Astrophysics Data System (ADS)

    Machida, Masahiko; Kobayashi, Keita; Koyama, Tomio

    2013-08-01

    We explore quantum phases in intrinsic Josephson junction (IJJ) stacks, whose in-plane area is so small that the capacitive coupling has a dominant role in the superconducting phase dynamics. In such cases, the effective Hamiltonian for the superconducting phase can be mapped onto that of one-dimensional ferromagnetically-interacting spin model, whose spin length S depends on the magnitude of the on-site Coulomb repulsion. The ferromagnetic model for IJJ’s prefers synchronized quantum features in contrast to the antiferromagnetically-interacting model in the conventional Josephson junction arrays.

  1. Single intrinsic Josephson junction with double-sided fabrication technique

    NASA Astrophysics Data System (ADS)

    You, L. X.; Torstensson, M.; Yurgens, A.; Winkler, D.; Lin, C. T.; Liang, B.

    2006-05-01

    We make stacks of intrinsic Josephson junctions (IJJs) embedded in the bulk of very thin (d⩽100nm) Bi2Sr2CaCu2O8+x single crystals. By precisely controlling the etching depth during the double-sided fabrication process, the stacks can be reproducibly tailor-made to be of any microscopic height (0-9nm

  2. Dynamic differential imaging of intrinsic optical responses in the retina

    NASA Astrophysics Data System (ADS)

    Yao, Xin-Cheng; Li, Yang-Guo; Liu, Lei; Amthor, Frank

    2010-02-01

    High resolution monitoring of stimulus-evoked retinal neural activities is important for understanding retinal neural mechanisms, and for diagnosis of retinal disease and evaluation of treatment. Fast intrinsic optical signals (IOSs), which have the time courses comparable to retinal electrophysiological responses, hold the promise for high resolution imaging of retinal neural activities. However, application of fast IOS imaging has been hindered by contamination of slow, high magnitude, optical responses associated with transient hemodynamic and metabolic changes. We recently demonstrated the feasibility of separating fast IOSs from slow optical responses by combined dynamic differential imaging and high frequency flicker stimulation.

  3. Intrinsic fundamental frequency of vowels is moderated by regional dialect.

    PubMed

    Jacewicz, Ewa; Fox, Robert Allen

    2015-10-01

    There has been a long-standing debate whether the intrinsic fundamental frequency (IF0) of vowels is an automatic consequence of articulation or whether it is independently controlled by speakers to perceptually enhance vowel contrasts along the height dimension. This paper provides evidence from regional variation in American English that IF0 difference between high and low vowels is, in part, controlled and varies across dialects. The sources of this F0 control are socio-cultural and cannot be attributed to differences in the vowel inventory size. The socially motivated enhancement was found only in prosodically prominent contexts. PMID:26520352

  4. Intrinsic Monitoring Using Behaviour Models in IPv6 Networks

    NASA Astrophysics Data System (ADS)

    Höfig, Edzard; Coşkun, Hakan

    In conventional networks, correlating path information to resource utilisation on the granularity of packets is a hard problem when using policy-based traffic handling schemes. We introduce a new approach termed ‘intrinsic monitoring’ which relies on the use of IPv6 extension headers in combination with formal behaviour models to gather resource information along a path. This allows a network monitoring system to delegate monitoring functionality to the network devices themselves, with the result of a drastic reduction in management traffic due to the increased autonomy of the monitoring system. As monitoring information travels in-band with the network traffic, path information remains perfectly accurate.

  5. Intrinsic irreversibility limits the efficiency of multidimensional molecular motors.

    PubMed

    Jack, M W; Tumlin, C

    2016-05-01

    We consider the efficiency limits of Brownian motors able to extract work from the temperature difference between reservoirs or from external thermodynamic forces. These systems can operate in a variety of modes, including as isothermal engines, heat engines, refrigerators, and heat pumps. We derive analytical results showing that certain classes of multidimensional Brownian motor, including the Smoluchowski-Feynman ratchet, are unable to attain perfect efficiency (Carnot efficiency for heat engines). This demonstrates the presence of intrinsic irreversibilities in their operating mechanism. We present numerical simulations showing that in some cases the loss process that limits efficiency is associated with vortices in the probability current.

  6. Triptycene-Based Organic Molecules of Intrinsic Microporosity

    PubMed Central

    2014-01-01

    Four Organic Molecules of Intrinsic Microporosity (OMIMs) were prepared by fusing triptycene-based components to a biphenyl core. Due to their rigid molecular structures that cannot pack space efficiently, these OMIMs form amorphous materials with significant microporosity as demonstrated by apparent BET surface areas in the range of 515–702 m2 g–1. Bulky cyclic 1′,2′,3′,4′-tetrahydro-1′,1′,4′,4′-tetramethylbenzo units placed on the triptycene termini are especially efficient at enhancing microporosity. PMID:24635193

  7. Indirect porcelain veneer technique for restoring intrinsically stained teeth.

    PubMed

    Cutbirth, S T

    1992-01-01

    Indirect porcelain veneers are often the ideal restoration for intrinsically stained teeth. This article details a step-by-step procedure for esthetically restoring discolored teeth. Porcelain laminate veneers are often indicated when teeth bleaching or direct composite bonding procedures cannot provide the desired esthetic result. Veneers are more appealing to many patients than full coverage crowns because of the more conservative tooth preparation required. If technique details are followed meticulously and cases are appropriately selected, porcelain veneers are not only durable but also promote marvelous gingival health and may be the most esthetic anterior dental restoration.

  8. Parametric resonance of intrinsic localized modes in coupled cantilever arrays

    NASA Astrophysics Data System (ADS)

    Kimura, Masayuki; Matsushita, Yasuo; Hikihara, Takashi

    2016-08-01

    In this study, the parametric resonances of pinned intrinsic localized modes (ILMs) were investigated by computing the unstable regions in parameter space consisting of parametric excitation amplitude and frequency. In the unstable regions, the pinned ILMs were observed to lose stability and begin to fluctuate. A nonlinear Klein-Gordon, Fermi-Pasta-Ulam-like, and mixed lattices were investigated. The pinned ILMs, particularly in the mixed lattice, were destabilized by parametric resonances, which were determined by comparing the shapes of the unstable regions with those in the Mathieu differential equation. In addition, traveling ILMs could be generated by parametric excitation.

  9. Intrinsic magnetic refrigeration of a single electron transistor

    NASA Astrophysics Data System (ADS)

    Ciccarelli, C.; Campion, R. P.; Gallagher, B. L.; Ferguson, A. J.

    2016-02-01

    In this work, we show that aluminium doped with low concentrations of magnetic impurities can be used to fabricate quantum devices with intrinsic cooling capabilities. We fabricate single electron transistors made of aluminium doped with 2% Mn by using a standard multi angle evaporation technique and show that the quantity of metal used to fabricate the devices generates enough cooling power to achieve a drop of 160 mK in the electron temperature at the base temperature of our cryostat (300 mK). The cooling mechanism is based on the magneto-caloric effect from the diluted Mn moments.

  10. NMR contributions to structural dynamics studies of intrinsically disordered proteins☆

    PubMed Central

    Konrat, Robert

    2014-01-01

    Intrinsically disordered proteins (IDPs) are characterized by substantial conformational plasticity. Given their inherent structural flexibility X-ray crystallography is not applicable to study these proteins. In contrast, NMR spectroscopy offers unique opportunities for structural and dynamic studies of IDPs. The past two decades have witnessed significant development of NMR spectroscopy that couples advances in spin physics and chemistry with a broad range of applications. This article will summarize key advances in basic physical-chemistry and NMR methodology, outline their limitations and envision future R&D directions. PMID:24656082

  11. Functionally defined therapeutic targets in diffuse intrinsic pontine glioma.

    PubMed

    Grasso, Catherine S; Tang, Yujie; Truffaux, Nathalene; Berlow, Noah E; Liu, Lining; Debily, Marie-Anne; Quist, Michael J; Davis, Lara E; Huang, Elaine C; Woo, Pamelyn J; Ponnuswami, Anitha; Chen, Spenser; Johung, Tessa B; Sun, Wenchao; Kogiso, Mari; Du, Yuchen; Qi, Lin; Huang, Yulun; Hütt-Cabezas, Marianne; Warren, Katherine E; Le Dret, Ludivine; Meltzer, Paul S; Mao, Hua; Quezado, Martha; van Vuurden, Dannis G; Abraham, Jinu; Fouladi, Maryam; Svalina, Matthew N; Wang, Nicholas; Hawkins, Cynthia; Nazarian, Javad; Alonso, Marta M; Raabe, Eric H; Hulleman, Esther; Spellman, Paul T; Li, Xiao-Nan; Keller, Charles; Pal, Ranadip; Grill, Jacques; Monje, Michelle

    2015-06-01

    Diffuse intrinsic pontine glioma (DIPG) is a fatal childhood cancer. We performed a chemical screen in patient-derived DIPG cultures along with RNA-seq analyses and integrated computational modeling to identify potentially effective therapeutic strategies. The multi-histone deacetylase inhibitor panobinostat demonstrated therapeutic efficacy both in vitro and in DIPG orthotopic xenograft models. Combination testing of panobinostat and the histone demethylase inhibitor GSK-J4 revealed that the two had synergistic effects. Together, these data suggest a promising therapeutic strategy for DIPG.

  12. Incidental Diagnosis of Diffuse Intrinsic Pontine Glioma in Children

    PubMed Central

    Wright, K. D.; Sabin, N. D.; Cheuk, D.; McNall-Knapp, R. Y.; Shurtleff, S. A.; Gajjar, A.; Broniscer, A.

    2014-01-01

    Children with diffuse intrinsic pontine glioma (DIPG) have a short onset, rapidly progressive neurologic decline before diagnosis. Therefore, incidental diagnosis of such an aggressive cancer is counterintuitive, yet our experience shows DIPG may occur as part of a spectrum of incidentally diagnosed pediatric brain cancers. Although children with incidentally diagnosed DIPG may experience a longer survival, it remains a potentially deadly cancer despite treatment with radiotherapy. Histologic confirmation is warranted when feasible in such patients to confirm diagnosis. Moreover, recent advances in genome-wide analyses may suggest incidentally diagnosed DIPGs are biologically distinct from the majority of these cancers. PMID:25598012

  13. Intrinsic irreversibility limits the efficiency of multidimensional molecular motors

    NASA Astrophysics Data System (ADS)

    Jack, M. W.; Tumlin, C.

    2016-05-01

    We consider the efficiency limits of Brownian motors able to extract work from the temperature difference between reservoirs or from external thermodynamic forces. These systems can operate in a variety of modes, including as isothermal engines, heat engines, refrigerators, and heat pumps. We derive analytical results showing that certain classes of multidimensional Brownian motor, including the Smoluchowski-Feynman ratchet, are unable to attain perfect efficiency (Carnot efficiency for heat engines). This demonstrates the presence of intrinsic irreversibilities in their operating mechanism. We present numerical simulations showing that in some cases the loss process that limits efficiency is associated with vortices in the probability current.

  14. Intrinsic irreversibility limits the efficiency of multidimensional molecular motors.

    PubMed

    Jack, M W; Tumlin, C

    2016-05-01

    We consider the efficiency limits of Brownian motors able to extract work from the temperature difference between reservoirs or from external thermodynamic forces. These systems can operate in a variety of modes, including as isothermal engines, heat engines, refrigerators, and heat pumps. We derive analytical results showing that certain classes of multidimensional Brownian motor, including the Smoluchowski-Feynman ratchet, are unable to attain perfect efficiency (Carnot efficiency for heat engines). This demonstrates the presence of intrinsic irreversibilities in their operating mechanism. We present numerical simulations showing that in some cases the loss process that limits efficiency is associated with vortices in the probability current. PMID:27300832

  15. Intrinsic fundamental frequency of vowels is moderated by regional dialect.

    PubMed

    Jacewicz, Ewa; Fox, Robert Allen

    2015-10-01

    There has been a long-standing debate whether the intrinsic fundamental frequency (IF0) of vowels is an automatic consequence of articulation or whether it is independently controlled by speakers to perceptually enhance vowel contrasts along the height dimension. This paper provides evidence from regional variation in American English that IF0 difference between high and low vowels is, in part, controlled and varies across dialects. The sources of this F0 control are socio-cultural and cannot be attributed to differences in the vowel inventory size. The socially motivated enhancement was found only in prosodically prominent contexts.

  16. Resonant tunneling and intrinsic bistability in twisted graphene structures

    NASA Astrophysics Data System (ADS)

    Rodriguez-Nieva, J. F.; Dresselhaus, M. S.; Levitov, L. S.

    2016-08-01

    We predict that vertical transport in heterostructures formed by twisted graphene layers can exhibit a unique bistability mechanism. Intrinsically bistable I -V characteristics arise from resonant tunneling and interlayer charge coupling, enabling multiple stable states in the sequential tunneling regime. We consider a simple trilayer architecture, with the outer layers acting as the source and drain and the middle layer floating. Under bias, the middle layer can be either resonant or nonresonant with the source and drain layers. The bistability is controlled by geometric device parameters easily tunable in experiments. The nanoscale architecture can enable uniquely fast switching times.

  17. Diffractive Higgs Production from Intrinsic Heavy Flavors in the Proton

    SciTech Connect

    Brodsky, Stanley J.; Kopeliovich, Boris; Schmidt, Ivan; Soffer, Jacques

    2006-03-31

    We propose a novel mechanism for exclusive diffractive Higgs production pp {yields} pHp in which the Higgs boson carries a significant fraction of the projectile proton momentum. This mechanism will provide a clear experimental signal for Higgs production due to the small background in this kinematic region. The key assumption underlying our analysis is the presence of intrinsic heavy flavor components of the proton bound state, whose existence at high light-cone momentum fraction x has growing experimental and theoretical support. We also discuss the implications of this picture for exclusive diffractive quarkonium and other channels.

  18. Sapphire-fiber-based intrinsic Fabry-Perot interferometer

    NASA Technical Reports Server (NTRS)

    Wang, Anbo; Gollapudi, Sridhar; Murphy, Kent A.; May, Russell G.; Claus, Richard O.

    1992-01-01

    A sapphire optical fiber intrinsic Fabry-Perot interferometric sensor is demonstrated. A length of multimode sapphire fiber that functions as a Fabry-Perot cavity is spliced to a silica single-mode fiber. The interferometric signals of this sensor are produced by the interference between the reflection from the silica-sapphire fiber splice and the reflection from the free end face of the sapphire fiber. This sensor has been demonstrated for temperature measurement. A resolution of 0.2 C has been obtained over a measurement range of 310 C to 976 C.

  19. Environmental preservation demand: Altruistic, bequest, and intrinsic motives

    SciTech Connect

    Whitehead, J.C.; Thompson, C.Y. )

    1993-01-01

    When the demand for environmental preservation is not explicitly revealed in markets, motivating attitudes toward environmental preservation become important. A survey approach allows revelation and measurement of demand for environmental preservation. Indices which measure the altruistic, bequest, intrinsic, and option to use motives and other attitudes are utilized as determinants in a model that measures the demand for environmental preservation. Demand is more likely with greater preservation motives. Preservation demand also depends on individual preferences for economic development, perceptions of affordability and responsibility for preservation of the wetlands. 17 refs., 3 tabs.

  20. Properties of n-dimensional triangulations

    NASA Technical Reports Server (NTRS)

    Lawson, Charles L.

    1986-01-01

    This paper establishes a number of mathematical results relevant to the problem of constructing a triangulation, i.e., a simplical tessellation of the convex hull of an arbitrary finite set of points in n-space. The principal results of the present paper are: (1) a set of n + 2 points in n-space may be triangulated in at most 2 different ways; (2) the 'sphere test' defined in this paper selects a preferred one of these two triangulations; (3) a set of parameters is defined that permits the characterization and enumeration of all sets on n + 2 points in n-space that are significantly different from the point of view of their possible triangulations; and (4) the local sphere test induces a global sphere test property for a triangulation.

  1. Evaluating Assessment Using N-Dimensional Filtering.

    ERIC Educational Resources Information Center

    Dron, Jon; Boyne, Chris; Mitchell, Richard

    This paper describes the use of the CoFIND (Collaborative Filter in N Dimensions) system to evaluate two assessment styles. CoFIND is a resource database that organizes itself around its users' needs. Learners enter resources, categorize, then rate them using "qualities," aspects of resources which learners find worthwhile, the n dimensions of…

  2. Intrinsic and extrinsic motives for originally following a sport team and team identification.

    PubMed

    Wann, D L; Ensor, C L; Bilyeu, J K

    2001-10-01

    Research indicates that both highly and lowly identified fans are more likely to be intrinsically than extrinsically motivated and that highly identified fans have a particularly strong inclination for intrinsic motivation. The current investigation was designed to extend this work by examining the relationship between level of identification and one's intrinsic and extrinsic motives for originally following a sport team. Preference for intrinsic motives for originally following a team should be highest among those high on team identification. 88 participants completed questionnaires containing the Sport Spectator Identification Scale and items assessing their intrinsic and extrinsic motives for originally identifying with a team. Analyses provided clear support for the hypotheses. PMID:11769901

  3. Generation and Detection of THz Radiation Using Intrinsic Josephson Junctions

    NASA Astrophysics Data System (ADS)

    Irie, Akinobu; Oikawa, Dai; Oya, Gin-ichiro

    We present the generation and detection of terahertz radiation using intrinsic Josephson junctions (IJJs) in Bi2Sr2CaCu2Oy single crystals. This approach allows us to detect THz radiation from large stacks consisting of a few hundred intrinsic Josephson junctions. The lateral dimensions of the fabricated IJJ oscillator mesa range from 290×50 to 290×90 μm2 and the number of IJJs which constitute the mesas is between 100 and 450, while the small mesa with the lateral dimensions of 5 × 5 μm2 is used as the high sensitive THz detector. The largest emission is always observed when the oscillator is biased at the negative resistance region of the current-voltage characteristics. We find that the emission frequency cor-responds to the second harmonics of the in-phase cavity resonance mode. This is consistent with the emission condition of the case of thick IJJ stacks reported previously.

  4. An intrinsically safe mechanism for physically coupling humans with robots.

    PubMed

    O'Neill, Gerald; Patel, Harshil; Artemiadis, Panagiotis

    2013-06-01

    Robots are increasingly used in tasks that include physical interaction with humans. Examples can be found in the area of rehabilitation robotics, power augmentation robots, as well as assistive and orthotic devices. However, current methods of physically coupling humans with robots fail to provide intrinsic safety, adaptation and efficiency, which limit the application of wearable robotics only to laboratory and controlled environments. In this paper we present the design and verification of a novel mechanism for physically coupling humans and robots. The device is intrinsically safe, since it is based on passive, non-electric features that are not prone to malfunctions. The device is capable of transmitting forces and torques in all directions between the human user and the robot. Moreover, its re-configurable nature allows for easy and consistent adjustment of the decoupling force. The latter makes the mechanism applicable to a wide range of human-robot coupling applications, ranging from low-force rehabilitation-therapy scenarios to high-force augmentation cases.

  5. Elastin-like Polypeptides as Models of Intrinsically Disordered Proteins

    PubMed Central

    Roberts, Stefan; Dzuricky, Michael; Chilkoti, Ashutosh

    2015-01-01

    Elastin-like polypeptides (ELPs) are a class of stimuli-responsive biopolymers inspired by the intrinsically disordered domains of tropoelastin that are composed of repeats of the VPGXG pentapeptide motif, where X is a “guest residue”. They undergo a reversible, thermally triggered lower critical solution temperature (LCST) phase transition, which has been utilized for a variety of applications including protein purification, affinity capture, immunoassays, and drug delivery. ELPs have been extensively studied as protein polymers and as biomaterials, but their relationship to other disordered proteins has heretofore not been established. The biophysical properties of ELPs that lend them their unique material behavior are similar to the properties of many intrinsically disordered proteins (IDP). Their low sequence complexity, phase behavior, and elastic properties make them an interesting “minimal” artificial IDP, and the study of ELPs can hence provide insights into the behavior of other more complex IDPs. Motivated by this emerging realization of the similarities between ELPs and IDPs, this review discusses the biophysical properties of ELPs, their biomedical utility, and their relationship to other disordered polypeptide sequences. PMID:26325592

  6. Intrinsic germanium detector used in borehole sonde for uranium exploration

    USGS Publications Warehouse

    Senftle, F.E.; Moxham, R.M.; Tanner, A.B.; Boynton, G.R.; Philbin, P.W.; Baicker, J.A.

    1976-01-01

    A borehole sonde (~1.7 m long; 7.3 cm diameter) using a 200 mm2 planar intrinsic germanium detector, mounted in a cryostat cooled by removable canisters of frozen propane, has been constructed and tested. The sonde is especially useful in measuring X- and low-energy gamma-ray spectra (40–400 keV). Laboratory tests in an artificial borehole facility indicate its potential for in-situ uranium analyses in boreholes irrespective of the state of equilibrium in the uranium series. Both natural gamma-ray and neutron-activation gamma-ray spectra have been measured with the sonde. Although the neutron-activation technique yields greater sensitivity, improvements being made in the resolution and efficiency of intrinsic germanium detectors suggest that it will soon be possible to use a similar sonde in the passive mode for measurement of uranium in a borehole down to about 0.1% with acceptable accuracy. Using a similar detector and neutron activation, the sonde can be used to measure uranium down to 0.01%.

  7. Factor XIa induced activation of the intrinsic cascade in vivo.

    PubMed

    ten Cate, H; Biemond, B J; Levi, M; Wuillemin, W A; Bauer, K A; Barzegar, S; Buller, H R; Hack, C E; ten Cate, J W; Rosenberg, R D

    1996-03-01

    Coagulation factor XI is a glycoprotein of the contact factor system. Its deficiency is associated with a highly variable bleeding tendency, thus a role in relation to hemostasis appears to exist. However, the importance of factor XI for stimulating intrinsic coagulation in vivo has not yet been determined. To study the procoagulant effects of human factor XIa in vivo, we infused the purified enzyme into normal chimpanzees (100 micrograms) in the absence or presence of the thrombin inhibitor rec-hirudin (1.0 mg/kg loading dose plus 0.3 mg/kg body wt continuous infusion). Factor XIa elicited an immediate activation of factors IX, X, and prothrombin, as measured by their respective activation fragments. However, whereas the activation of factors IX and X was immediate and shortlasting, (peak increments of 6- and 1.4-fold of baseline at 5 minutes after injection), the conversion of prothrombin gradually increased, reaching a summit of 6-fold baseline values after 60 min, and remaining elevated during the course of the experiments. Thrombin-antithrombin complexes also remained elevated during the study period. In the presence of hirudin, the initial activation of factors IX, X, and prothrombin was unchanged, however the further increment in prothrombin fragment F1 + 2 was markedly inhibited. These results demonstrate that factor XIa is a potential agonist of the intrinsic cascade in vivo, which activity is enhanced in the presence of thrombin.

  8. Revisiting Intrinsic Curves for Efficient Dense Stereo Matching

    NASA Astrophysics Data System (ADS)

    Shahbazi, M.; Sohn, G.; Théau, J.; Ménard, P.

    2016-06-01

    Dense stereo matching is one of the fundamental and active areas of photogrammetry. The increasing image resolution of digital cameras as well as the growing interest in unconventional imaging, e.g. unmanned aerial imagery, has exposed stereo image pairs to serious occlusion, noise and matching ambiguity. This has also resulted in an increase in the range of disparity values that should be considered for matching. Therefore, conventional methods of dense matching need to be revised to achieve higher levels of efficiency and accuracy. In this paper, we present an algorithm that uses the concepts of intrinsic curves to propose sparse disparity hypotheses for each pixel. Then, the hypotheses are propagated to adjoining pixels by label-set enlargement based on the proximity in the space of intrinsic curves. The same concepts are applied to model occlusions explicitly via a regularization term in the energy function. Finally, a global optimization stage is performed using belief-propagation to assign one of the disparity hypotheses to each pixel. By searching only through a small fraction of the whole disparity search space and handling occlusions and ambiguities, the proposed framework could achieve high levels of accuracy and efficiency.

  9. The architecture and contraction time of intrinsic foot muscles.

    PubMed

    Tosovic, Danijel; Ghebremedhin, Estifanos; Glen, Christopher; Gorelick, Mark; Mark Brown, J

    2012-12-01

    Although critical for effective human locomotion and posture, little data exists regarding the segmentation, architecture and contraction time of the human intrinsic foot muscles. To address this issue, the Abductor Hallucis (AH), Abductor Digiti Minimi (ADM), Flexor Digitorum Brevis (FDB) and Extensor Digitorum Brevis (EDB) were investigated utilizing a cadaveric dissection and a non-invasive whole muscle mechanomyographic (wMMG) technique. The segmental structure and architecture of formaldehyde-fixed foot specimens were determined in nine cadavers aged 60-80 years. The wMMG technique was used to determine the contraction time (Tc) of individual muscle segments, within each intrinsic foot muscle, in 12 volunteers of both genders aged between 19 and 24 years. While the pattern of segmentation and segmental -architecture (e.g. fibre length) and -Tc of individual muscle segments within the same muscle were similar, they varied between muscles. Also, the average whole muscle Tc of FDB was significantly (p < 0.05) shorter (faster) (Tc = 58 ms) than in all other foot muscles investigated (ADM Tc = 72 ms, EDB Tc = 72 ms and ABH Tc = 69 ms). The results suggest that the architecture and contraction time of the FDB reflect its unique direct contribution, through toe flexion, to postural stability and the rapid development of ground reaction forces during forceful activities such as running and jumping.

  10. Direct Mapping of Hippocampal Surfaces with Intrinsic Shape Context

    PubMed Central

    Shi, Yonggang; Thompson, Paul M.; de Zubicaray, Greig I.; Rose, Stephen E.; Tu, Zhuowen; Dinov, Ivo; Toga, Arthur W.

    2007-01-01

    We propose in this paper a new method for the mapping of hippocampal (HC) surfaces to establish correspondences between points on HC surfaces and enable localized HC shape analysis. A novel geometric feature, the intrinsic shape context, is defined to capture the global characteristics of the HC shapes. Based on this intrinsic feature, an automatic algorithm is developed to detect a set of landmark curves that are stable across population. The direct map between a source and target HC surface is then solved as the minimizer of a harmonic energy function defined on the source surface with landmark constraints. For numerical solutions, we compute the map with the approach of solving partial differential equations on implicit surfaces. The direct mapping method has the following properties: 1) it has the advantage of being automatic; 2) it is invariant to the pose of HC shapes. In our experiments, we apply the direct mapping method to study temporal changes of HC asymmetry in Alzheimer disease (AD) using HC surfaces from 12 AD patients and 14 normal controls. Our results show that the AD group has a different trend in temporal changes of HC asymmetry than the group of normal controls. We also demonstrate the flexibility of the direct mapping method by applying it to construct spherical maps of HC surfaces. Spherical harmonics (SPHARM) analysis is then applied and it confirms our results about temporal changes of HC asymmetry in AD. PMID:17625918

  11. Quantal rotation and its coupling to intrinsic motion in nuclei

    NASA Astrophysics Data System (ADS)

    Nakatsukasa, Takashi; Matsuyanagi, Kenichi; Matsuzaki, Masayuki; Shimizu, Yoshifumi R.

    2016-07-01

    Symmetry breaking is an important concept in nuclear physics and other fields of physics. Self-consistent coupling between the mean-field potential and the single-particle motion is a key ingredient in the unified model of Bohr and Mottelson, which could lead to a deformed nucleus as a consequence of spontaneous breaking of the rotational symmetry. Some remarks on the finite-size quantum effects are given. In finite nuclei, the deformation inevitably introduces the rotation as a symmetry-restoring collective motion (Anderson–Nambu–Goldstone mode), and the rotation affects the intrinsic motion. In order to investigate the interplay between the rotational and intrinsic motions in a variety of collective phenomena, we use the cranking prescription together with the quasiparticle random phase approximation (QRPA). At low spin, the coupling effect can be seen in the generalized intensity relation. A feasible quantization of the cranking model is presented, which provides a microscopic approach to the higher-order intensity relation. At high spin, the semiclassical cranking prescription works well. We discuss properties of collective vibrational motions under rapid rotation and/or large deformation. The superdeformed shell structure plays a key role in emergence of a new soft mode which could lead to instability toward the {K}π ={1}- octupole shape. A wobbling mode of excitation, which is a clear signature of the triaxiality, is discussed in terms of a microscopic point of view. A crucial role played by the quasiparticle alignment is presented.

  12. Redefining Field Capacity: Intrinsic Criteria for Soil Internal Drainage Dynamics

    NASA Astrophysics Data System (ADS)

    Assouline, S.; Or, D.

    2014-12-01

    Across many soil types and conditions, soil internal drainage exhibits predictable dynamics that converge to a stable hydration state termed "field capacity" (FC). Notwithstanding the usefulness of this natural state as a hydrologic benchmark for modeling and for estimation of plant available soil water, FC had been fraught with ambiguities and inconsistencies since its inception. We propose using a soil intrinsic characteristic length (derived from drainable soil pore size distribution) to mark conditions for loss of hydraulic continuity linked with attainment of FC. This static criterion for FC was extended to define a general and self-consistent dynamic criterion for internal drainage dynamics. A systematic evaluation of the proposed FC definitions using a numerical model and experimental data reveals remarkable consistency and predictability across a wide range of soil types. The new intrinsic metrics provide the necessary definitiveness for this useful concept relevant to a broad range of agronomic, hydrologic, ecological and climatic applications. The consistency of FC hydration state must have played an important role in shaping life in soil not only in terms of plant available water, but also in the aquatic habitats it defines for soil biota.

  13. Redefining field capacity: intrinsic criteria for soil internal drainage dynamics

    NASA Astrophysics Data System (ADS)

    Assouline, Shmuel; Or, Dani

    2015-04-01

    Across many soil types and conditions, soil internal drainage exhibits predictable dynamics that converge to a stable hydration state termed "field capacity" (FC). Notwithstanding the usefulness of this natural state as a hydrologic benchmark for modeling and for estimation of plant available soil water, FC had been fraught with ambiguities and inconsistencies since its inception. We propose using a soil intrinsic characteristic length (derived from drainable soil pore size distribution) to mark conditions for loss of hydraulic continuity linked with attainment of FC. This static criterion for FC was extended to define a general and self-consistent dynamic criterion for internal drainage dynamics. A systematic evaluation of the proposed FC definitions using a numerical model and experimental data reveals remarkable consistency and predictability across a wide range of soil types. The new intrinsic metrics provide the necessary definitiveness for this useful concept relevant to a broad range of agronomic, hydrologic, ecological and climatic applications. The consistency of FC hydration state must have played an important role in shaping life in soil not only in terms of plant available water, but also in the aquatic habitats it defines for soil biota.

  14. Intrinsic half-metallicity in fractal carbon nitride honeycomb lattices.

    PubMed

    Wang, Aizhu; Zhao, Mingwen

    2015-09-14

    Fractals are natural phenomena that exhibit a repeating pattern "exactly the same at every scale or nearly the same at different scales". Defect-free molecular fractals were assembled successfully in a recent work [Shang et al., Nature Chem., 2015, 7, 389-393]. Here, we adopted the feature of a repeating pattern in searching two-dimensional (2D) materials with intrinsic half-metallicity and high stability that are desirable for spintronics applications. Using first-principles calculations, we demonstrate that the electronic properties of fractal frameworks of carbon nitrides have stable ferromagnetism accompanied by half-metallicity, which are highly dependent on the fractal structure. The ferromagnetism increases gradually with the increase of fractal order. The Curie temperature of these metal-free systems estimated from Monte Carlo simulations is considerably higher than room temperature. The stable ferromagnetism, intrinsic half-metallicity, and fractal characteristics of spin distribution in the carbon nitride frameworks open an avenue for the design of metal-free magnetic materials with exotic properties.

  15. Quantal rotation and its coupling to intrinsic motion in nuclei

    NASA Astrophysics Data System (ADS)

    Nakatsukasa, Takashi; Matsuyanagi, Kenichi; Matsuzaki, Masayuki; Shimizu, Yoshifumi R.

    2016-07-01

    Symmetry breaking is an important concept in nuclear physics and other fields of physics. Self-consistent coupling between the mean-field potential and the single-particle motion is a key ingredient in the unified model of Bohr and Mottelson, which could lead to a deformed nucleus as a consequence of spontaneous breaking of the rotational symmetry. Some remarks on the finite-size quantum effects are given. In finite nuclei, the deformation inevitably introduces the rotation as a symmetry-restoring collective motion (Anderson-Nambu-Goldstone mode), and the rotation affects the intrinsic motion. In order to investigate the interplay between the rotational and intrinsic motions in a variety of collective phenomena, we use the cranking prescription together with the quasiparticle random phase approximation (QRPA). At low spin, the coupling effect can be seen in the generalized intensity relation. A feasible quantization of the cranking model is presented, which provides a microscopic approach to the higher-order intensity relation. At high spin, the semiclassical cranking prescription works well. We discuss properties of collective vibrational motions under rapid rotation and/or large deformation. The superdeformed shell structure plays a key role in emergence of a new soft mode which could lead to instability toward the {K}π ={1}- octupole shape. A wobbling mode of excitation, which is a clear signature of the triaxiality, is discussed in terms of a microscopic point of view. A crucial role played by the quasiparticle alignment is presented.

  16. Extrinsic and Intrinsic Defects in Congruent and Stoichiometric Lithium Niobate

    NASA Astrophysics Data System (ADS)

    Malovichko, Galina; Grachev, Valentin

    2003-03-01

    Due to specific character of the phase diagram the crystals of Lithium Niobate (LN) grown by conventional Czochralski way are always Li-deficient, even if the melts have essential Li excess. Different dopants were used for desirable modification of crystal properties; however some observed discrepancies and partial irreproducibility of characteristics were not properly clarified. Essential progress in understanding of LN features was achieved after development of several ways enabling to obtain materials with [Li]/[Nb] ratio close to 1 (VTE treatment, double crucible growth, growth with potassium). Strong mutual dependence of subsystems of extrinsic (impurity) and intrinsic (nonstoichiometric) defects forms the talk topic. Spectra of EPR, NMR, ENDOR, HREM, optical and X-ray data have been analysed for crystals with different compositions, diverse modifiers and various probe impurities. Most of the results show clearly: 1) presence of correlated complexes of intrinsic defects in undoped samples; 2) correlated entering of impurities and charge compensating defects in doped crystals; 3) qualitative difference between structures of the impurity centers substituting for Li or Nb ions in conventional and stoichiometric materials. Crystals with the extremely low concentration of defects offer extraordinary informative opportunities (due to tremendous resolution enhancement), whereas materials of nonstoichiometric composition are especially suitable for tailoring material properties.

  17. Changing the Environment Based on Empowerment as Intrinsic Motivation

    NASA Astrophysics Data System (ADS)

    Salge, Christoph; Glackin, Cornelius; Polani, Daniel

    2014-05-01

    One aspect of intelligence is the ability to restructure your own environment so that the world you live in becomes more beneficial to you. In this paper we investigate how the information-theoretic measure of agent empowerment can provide a task-independent, intrinsic motivation to restructure the world. We show how changes in embodiment and in the environment change the resulting behaviour of the agent and the artefacts left in the world. For this purpose, we introduce an approximation of the established empowerment formalism based on sparse sampling, which is simpler and significantly faster to compute for deterministic dynamics. Sparse sampling also introduces a degree of randomness into the decision making process, which turns out to beneficial for some cases. We then utilize the measure to generate agent behaviour for different agent embodiments in a Minecraft-inspired three dimensional block world. The paradigmatic results demonstrate that empowerment can be used as a suitable generic intrinsic motivation to not only generate actions in given static environments, as shown in the past, but also to modify existing environmental conditions. In doing so, the emerging strategies to modify an agent's environment turn out to be meaningful to the specific agent capabilities, i.e., de facto to its embodiment.

  18. Intrinsic Feature Pose Measurement for Awake Animal SPECT Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Lee, Seung Joon; Weisenberger, A G; Stolin, A; McKisson, J; Smith, M F

    2009-01-01

    New developments have been made in optical motion tracking for awake animal imaging that measures 3D position and orientation (pose) for a single photon emission computed tomography (SPECT) imaging system. Ongoing SPECT imaging research has been directed towards head motion measurement for brain studies in awake, unrestrained mice. In contrast to previous results using external markers, this work extracts and tracks intrinsic features from multiple camera images and computes relative pose from the tracked features over time. Motion tracking thus far has been limited to measuring extrinsic features such as retro-reflective markers applied to the mouse s head. While this approach has been proven to be accurate, the additional animal handling required to attach the markers is undesirable. A significant improvement in the procedure is achieved by measuring the pose of the head without extrinsic markers using only the external surface appearance. This approach is currently being developed with initial results presented here. The intrinsic features measurement extracts discrete, sparse natural features from 2D images such as eyes, nose, mouth and other visible structures. Stereo correspondence between features for a camera pair is determined for calculation of 3D positions. These features are also tracked over time to provide continuity for surface model fitting. Experimental results from live images are presented.

  19. Towards the Better: Intrinsic Property Amelioration in Bulk Metallic Glasses.

    PubMed

    Sarac, Baran; Zhang, Long; Kosiba, Konrad; Pauly, Simon; Stoica, Mihai; Eckert, Jürgen

    2016-01-01

    Tailoring the intrinsic length-scale effects in bulk metallic glasses (BMGs) via post-heat treatment necessitates a systematic analyzing strategy. Although various achievements were made in the past years to structurally enhance the properties of different BMG alloys, the influence of short-term sub-glass transition annealing on the relaxation kinetics is still not fully covered. Here, we aim for unraveling the connection between the physical, (thermo)mechanical and structural changes as a function of selected pre-annealing temperatures and time scales with an in-house developed Cu46Zr44Al8Hf2 based BMG alloy. The controlled formation of nanocrystals below 50 nm with homogenous distribution inside the matrix phase via thermal treatment increase the material's resistance to strain softening by almost an order of magnitude. The present work determines the design aspects of metallic glasses with enhanced mechanical properties via nanostructural modifications, while postulating a counter-argument to the intrinsic property degradation accounted for long-term annealing. PMID:27273477

  20. Effects of intrinsic and extrinsic motivation on attention and memory.

    PubMed

    Robinson, Lucy J; Stevens, Lucy H; Threapleton, Christopher J D; Vainiute, Jurgita; McAllister-Williams, R Hamish; Gallagher, Peter

    2012-10-01

    It is well recognised that motivational factors can influence neuropsychological performance. The aim of this study was to explore individual differences in intrinsic motivation and reward-seeking and the effect of these on attentional and mnemonic processes, in the presence or absence of financial incentives. Forty participants (18-35years) completed two testing sessions where the Attentional Network Test (ANT) and the Newcastle Spatial Memory Test (NSMT) were administered. After a baseline assessment, participants were re-tested after randomisation to a non-motivated (control) group or to a motivated group, where payment was contingent upon performance. Performance in the motivated group was significantly improved compared to the control group on the NSMT (condition by session; F(1,33)=4.52, p=0.041) and the ANT, with participants increasing performance to cued presentations within the alerting network (F(1,36)=5.48, p=0.025) and being less distracted by incongruent stimuli in the executive control network (F(1,36)=6.74, p=0.014). There were significant negative correlations between the 'Interest/ Enjoyment' Intrinsic Motivation Inventory subscale and both NSMT between-search errors and ANT(alerting). In the motivated group, those who had higher self-reported internal motivation were less susceptible to- or affected by- the external motivation of financial incentive. The effects of motivational factors should not be overlooked when interpreting absolute levels of performance in neuropsychological processes.

  1. Intrinsic bioremediation of trichloroethylene and chlorobenzene: field and laboratory studies.

    PubMed

    Kao, C M; Prosser, J

    1999-10-01

    Activities at a former fire training area at Robins Air Force Base in Georgia, USA resulted in contamination of groundwater with a mixture of trichloroethylene (TCE) and chlorobenzene (CB). Results from the field investigation suggest that intrinsic bioremediation process is occurring, which caused the decrease in TCE and CB concentrations, and increase in TCE degradation byproducts [e.g., dichloroethylene isomers (DCEs), vinyl chloride (VC)] concentrations. Contaminated groundwater samples collected from this site were used to conduct microbial enumeration tests, and used as the inocula for microcosm establishment. Results from the microbial enumeration study indicate that methanogenesis was the dominant biodegradation pattern within the source and mid-plume areas, and the aerobic biodegradation process dominated the downgradient area. Laboratory microcosm experiments were conducted to evaluate the feasibility of using CB as the primary substrate to enhance the intrinsic biodegradation of TCE. Microcosm results suggest that CB can serve as the primary substrate (electron donor), and enhance TCE biodegradation to less-chlorinated compounds under both aerobic cometabolism and reductive dechlorination conditions.

  2. Towards the Better: Intrinsic Property Amelioration in Bulk Metallic Glasses

    PubMed Central

    Sarac, Baran; Zhang, Long; Kosiba, Konrad; Pauly, Simon; Stoica, Mihai; Eckert, Jürgen

    2016-01-01

    Tailoring the intrinsic length-scale effects in bulk metallic glasses (BMGs) via post-heat treatment necessitates a systematic analyzing strategy. Although various achievements were made in the past years to structurally enhance the properties of different BMG alloys, the influence of short-term sub-glass transition annealing on the relaxation kinetics is still not fully covered. Here, we aim for unraveling the connection between the physical, (thermo)mechanical and structural changes as a function of selected pre-annealing temperatures and time scales with an in-house developed Cu46Zr44Al8Hf2 based BMG alloy. The controlled formation of nanocrystals below 50 nm with homogenous distribution inside the matrix phase via thermal treatment increase the material’s resistance to strain softening by almost an order of magnitude. The present work determines the design aspects of metallic glasses with enhanced mechanical properties via nanostructural modifications, while postulating a counter-argument to the intrinsic property degradation accounted for long-term annealing. PMID:27273477

  3. Cooperative motion of intrinsic and actuated semiflexible swimmers

    NASA Astrophysics Data System (ADS)

    Llopis, I.; Pagonabarraga, I.; Cosentino Lagomarsino, M.; Lowe, C. P.

    2013-03-01

    We examine the phenomenon of hydrodynamic-induced cooperativity for pairs of flagellated micro-organism swimmers, of which spermatozoa cells are an example. We consider semiflexible swimmers, where inextensible filaments are driven by an internal intrinsic force and torque-free mechanism (intrinsic swimmers). The velocity gain for swimming cooperatively, which depends on both the geometry and the driving, develops as a result of the near-field coupling of bending and hydrodynamic stresses. We identify the regimes where hydrodynamic cooperativity is advantageous and quantify the change in efficiency. When the filaments' axes are parallel, hydrodynamic interaction induces a directional instability that causes semiflexible swimmers that profit from swimming together to move apart from each other. Biologically, this implies that flagella need to select different synchronized collective states and to compensate for directional instabilities (e.g., by binding) in order to profit from swimming together. By analyzing the cooperative motion of pairs of externally actuated filaments, we assess the impact that stress distribution along the filaments has on their collective displacements.

  4. Impact of hematocrit on measurements of the intrinsic brain.

    PubMed

    Yang, Zhen; Craddock, R Cameron; Milham, Michael P

    2014-01-01

    Blood oxygenation level dependent (BOLD)-based functional MRI (fMRI) is a widely utilized neuroimaging technique for mapping brain function. Hematocrit (HCT), a global hematologic marker of the amount of hemoglobin in blood, is known to impact task-evoked BOLD activation. Yet, its impact on resting-state fMRI (R-fMRI) measures has not been characterized. We address this gap by testing for associations between HCT level and inter-individual variation in commonly employed R-fMRI indices of intrinsic brain function from 45 healthy adults. Given known sex differences in HCT, we also examined potential sex differences. Variation in baseline HCT among individuals were associated with regional differences in four of the six intrinsic brain indices examined. Portions of the default (anterior cingulate cortex/medial prefrontal cortex: ACC/MPFC), dorsal attention (intraparietal sulcus), and salience (insular and opercular cortex) network showed relationships with HCT for two measures. The relationships within MPFC, as well as visual and cerebellar networks, were modulated by sex. These results suggest that inter-individual variations in HCT can serve as a source of variations in R-fMRI derivatives at a regional level. Future work is needed to delineate whether this association is attributable to neural or non-neuronal source of variations and whether these effects are related to acute or chronic differences in HCT level.

  5. Computational approaches for inferring the functions of intrinsically disordered proteins

    PubMed Central

    Varadi, Mihaly; Vranken, Wim; Guharoy, Mainak; Tompa, Peter

    2015-01-01

    Intrinsically disordered proteins (IDPs) are ubiquitously involved in cellular processes and often implicated in human pathological conditions. The critical biological roles of these proteins, despite not adopting a well-defined fold, encouraged structural biologists to revisit their views on the protein structure-function paradigm. Unfortunately, investigating the characteristics and describing the structural behavior of IDPs is far from trivial, and inferring the function(s) of a disordered protein region remains a major challenge. Computational methods have proven particularly relevant for studying IDPs: on the sequence level their dependence on distinct characteristics determined by the local amino acid context makes sequence-based prediction algorithms viable and reliable tools for large scale analyses, while on the structure level the in silico integration of fundamentally different experimental data types is essential to describe the behavior of a flexible protein chain. Here, we offer an overview of the latest developments and computational techniques that aim to uncover how protein function is connected to intrinsic disorder. PMID:26301226

  6. Intrinsic, nondeterministic circadian rhythm generation in identified mammalian neurons.

    PubMed

    Webb, Alexis B; Angelo, Nikhil; Huettner, James E; Herzog, Erik D

    2009-09-22

    Circadian rhythms are modeled as reliable and self-sustained oscillations generated by single cells. The mammalian suprachiasmatic nucleus (SCN) keeps near 24-h time in vivo and in vitro, but the identity of the individual cellular pacemakers is unknown. We tested the hypothesis that circadian cycling is intrinsic to a unique class of SCN neurons by measuring firing rate or Period2 gene expression in single neurons. We found that fully isolated SCN neurons can sustain circadian cycling for at least 1 week. Plating SCN neurons at <100 cells/mm(2) eliminated synaptic inputs and revealed circadian neurons that contained arginine vasopressin (AVP) or vasoactive intestinal polypeptide (VIP) or neither. Surprisingly, arrhythmic neurons (nearly 80% of recorded neurons) also expressed these neuropeptides. Furthermore, neurons were observed to lose or gain circadian rhythmicity in these dispersed cell cultures, both spontaneously and in response to forskolin stimulation. In SCN explants treated with tetrodotoxin to block spike-dependent signaling, neurons gained or lost circadian cycling over many days. The rate of PERIOD2 protein accumulation on the previous cycle reliably predicted the spontaneous onset of arrhythmicity. We conclude that individual SCN neurons can generate circadian oscillations; however, there is no evidence for a specialized or anatomically localized class of cell-autonomous pacemakers. Instead, these results indicate that AVP, VIP, and other SCN neurons are intrinsic but unstable circadian oscillators that rely on network interactions to stabilize their otherwise noisy cycling. PMID:19805326

  7. Size Scaling of Intrinsic Rotation in DIII-D

    NASA Astrophysics Data System (ADS)

    Degrassie, J. S.; Solomon, W. M.

    2015-11-01

    Despite the richness in the variety of the profiles of intrinsic rotation in axisymmetric tokamaks, a common feature is a co-Ip directed toroidal velocity on the outboard midplane in the region of ρ ~ 0 . 8 in DIII-D. This feature showed a ``Rice scaling'' (RS) in DIII-D and led to similarity experiments with C-Mod. RS correlates toroidal velocity with W/Ip, where W is the total plasma kinetic energy and Ip the plasma current. Subsequent analysis from DIII-D shows a clear ρ * dimensionless scaling of this intrinsic velocity in DIII-D, where ρ * ~ √Ti / aB , multiplying the βq scaling indicative of RS. The DIII-D scaling is MA ~βN ρ * , where MA is the Alfvén ``Mach'' value and βN is normalized β. In machine parameters it is very similar to the theoretical ``Parra scaling,'' which emphasizes the correlation of toroidal velocity with ion temperature as seen experimentally, but in this DIII-D scaling having an additional critical dependence on √β . Published data from C-Mod and low power ICRF in JET also fit with this DIII-D scaling. The relation to the RS will be described. Work supported in part by US DOE under DE-FC02-04ER54698 & DE-AC02-09CH11466.

  8. Towards the Better: Intrinsic Property Amelioration in Bulk Metallic Glasses

    NASA Astrophysics Data System (ADS)

    Sarac, Baran; Zhang, Long; Kosiba, Konrad; Pauly, Simon; Stoica, Mihai; Eckert, Jürgen

    2016-06-01

    Tailoring the intrinsic length-scale effects in bulk metallic glasses (BMGs) via post-heat treatment necessitates a systematic analyzing strategy. Although various achievements were made in the past years to structurally enhance the properties of different BMG alloys, the influence of short-term sub-glass transition annealing on the relaxation kinetics is still not fully covered. Here, we aim for unraveling the connection between the physical, (thermo)mechanical and structural changes as a function of selected pre-annealing temperatures and time scales with an in-house developed Cu46Zr44Al8Hf2 based BMG alloy. The controlled formation of nanocrystals below 50 nm with homogenous distribution inside the matrix phase via thermal treatment increase the material’s resistance to strain softening by almost an order of magnitude. The present work determines the design aspects of metallic glasses with enhanced mechanical properties via nanostructural modifications, while postulating a counter-argument to the intrinsic property degradation accounted for long-term annealing.

  9. Articulated navigation testbed (ANT): an example of adaptable intrinsic mobility

    NASA Astrophysics Data System (ADS)

    Brosinsky, Chris A.; Hanna, Doug M.; Penzes, Steven G.

    2000-07-01

    An important but oft overlooked aspect of any robotic system is the synergistic benefit of designing the chassis to have high intrinsic mobility which complements rather than limits, its system capabilities. This novel concept continues to be investigated by the Defence Research Establishment Suffield (DRES) with the Articulated Navigation Testbed (ANT) Unmanned Ground Vehicle (UGV). The ANT demonstrates high mobility through the combination of articulated steering and a hybrid locomotion scheme which utilizes individually powered wheels on the edge of rigid legs; legs which are capable of approximately 450 degrees of rotation. The configuration can be minimally configured as a 4x4 and modularly expanded to 6x6, 8x8, and so on. This enhanced mobility configuration permits pose control and novel maneuvers such as stepping, bridging, crawling, etc. Resultant mobility improvements, particularly in unstructured and off-road environments, will reduce the resolution with which the UGV sensor systems must perceive its surroundings and decreases the computational requirements of the UGV's perception systems1 for successful semi-autonomous or autonomous terrain negotiation. This paper reviews critical vehicle developments leading up to the ANT concept, describes the basis for its configuration and speculates on the impact of the intrinsic mobility concept for UGV effectiveness.

  10. Theoretical exploration of Josephson Plasma Emission in Intrinsic Josephson Junctions

    SciTech Connect

    Tachiki, M.; Machida, M.

    2000-07-18

    In this paper, the authors theoretically predict the best efficient way for electromagnetic wave emission by Josephson plasma excitation in intrinsic Josephson junctions. First, they briefly derive basic equations describing dynamics of phase differences inside junction sites in intrinsic Josephson junctions, and review the nature of Josephson plasma excitation modes based on the equations. Especially, they make an attention to that Josephson plasma modes have much different dispersion relations depending on the propagating directions and their different modes can be recognized as N standing waves propagating along ah-plane in cases of finite stacked systems composed of N junctions. Second, they consider how to excite their modes and point out that excitations of in-phase mode with the highest propagation velocity among their N modes are the most efficient way for electromagnetic wave emissions. Finally, they clarify that in-phase excitations over all junctions are possible by using Josephson vortex flow states. They show simulation results of Josephson vortex flow states resonating with some Josephson plasma modes and predict that superradiance of electromagnetic field may occur in rectangular vortex flow state in which spatiotemporal oscillations of electromagnetic fields are perfectly in-phase.

  11. Intrinsic and extrinsic regulation of cardiac lipoprotein lipase following diabetes.

    PubMed

    Wang, Ying; Rodrigues, Brian

    2015-02-01

    Cardiac lipoprotein lipase (LPL) is a pivotal enzyme controlling heart metabolism by providing the majority of fatty acids required by this organ. From activation in cardiomyocytes to secretion to the vascular lumen, cardiac LPL is regulated by multiple pathways, which are altered during diabetes. Hence, dimerization/activation of LPL is modified following diabetes, a process controlled by lipase maturation factor 1. The role of AMP-activated protein kinase, protein kinase D, and heparan sulfate proteoglycans, intrinsic factors that regulate the intracellular transport of LPL is also shifted, and is discussed. More recent studies have identified several exogenous factors released from endothelial cells (EC) and adipose tissue that are required for proper functioning of LPL. In response to hyperglycemia, both active and latent heparanase are released from EC to facilitate LPL secretion. Diabetes also increased the expression of glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1) in EC, which mediates the transport of LPL across EC. Angiopoietin-like protein 4 secreted from the adipose tissue has the potential to reduce coronary LPL activity. Knowledge of these intrinsic and extrinsic factors could be used develop therapeutic targets to normalize LPL function, and maintain cardiac energy homeostasis after diabetes. PMID:25463481

  12. Branching in current voltage characteristics of intrinsic Josephson junctions

    NASA Astrophysics Data System (ADS)

    Shukrinov, Yu M.; Mahfouzi, F.

    2007-02-01

    We study branching in the current-voltage characteristics of the intrinsic Josephson junctions of high-temperature superconductors in the framework of the capacitively coupled Josephson junction model with diffusion current. A system of dynamical equations for the gauge-invariant phase differences between superconducting layers for a stack of ten intrinsic junctions has been numerically solved. We have obtained a total branch structure in the current-voltage characteristics. We demonstrate the existence of a 'breakpoint region' on the current-voltage characteristics and explain it as a result of resonance between Josephson and plasma oscillations. The effect of the boundary conditions is investigated. The existence of two outermost branches and correspondingly two breakpoint regions for the periodic boundary conditions is shown. One branch, which is observed only at periodic boundary conditions, corresponds to the propagating of the plasma mode. The second one corresponds to the situation when the charge oscillations on the superconducting layers are absent, excluding the breakpoint. A time dependence of the charge oscillations at breakpoints is presented.

  13. Photoaging versus intrinsic aging: a morphologic assessment of facial skin.

    PubMed

    Bhawan, J; Andersen, W; Lee, J; Labadie, R; Solares, G

    1995-04-01

    Histologic studies have become increasingly important in recognizing morphologic differences in photoaged versus intrinsically aged skin. Earlier histologic studies have attempted to evaluate these changes by examining anatomical sites which are not comparable, such as face and buttocks. As part of a multicenter study, we have quantitatively examined a panel of 16 histologic features in baseline facial skin biopsies from 158 women with moderate to severe photodamage. When compared to the postauricular area (photo protected), biopsies of the crow's feet area (photo exposed) had a twofold increase in melanocytes and a statistically significant increase in melanocytic atypia (p < .0001) and epidermal melanin (p < .0001). Other epidermal changes included reduced epidermal thickness (p < .01), more compact stratum corneum (p < .0001) and increased granular layer thickness (p < .0001) in the crow's feet skin. There was increased solar elastosis (p < .0001), dermal elastic tissue (p < .0001), melanophages (p < .0001), perivascular inflammation (p < .05) and perifollicular fibrosis (p < .01) but no change in the number of mast cells or dermal mucin in the photo exposed skin. Our data document quantitative differences in photoaged versus intrinsically aged facial skin and provides the groundwork for future studies to evaluate the efficacy of new treatments for photoaged skin. PMID:7560349

  14. Photoaging versus intrinsic aging: a morphologic assessment of facial skin.

    PubMed

    Bhawan, J; Andersen, W; Lee, J; Labadie, R; Solares, G

    1995-04-01

    Histologic studies have become increasingly important in recognizing morphologic differences in photoaged versus intrinsically aged skin. Earlier histologic studies have attempted to evaluate these changes by examining anatomical sites which are not comparable, such as face and buttocks. As part of a multicenter study, we have quantitatively examined a panel of 16 histologic features in baseline facial skin biopsies from 158 women with moderate to severe photodamage. When compared to the postauricular area (photo protected), biopsies of the crow's feet area (photo exposed) had a twofold increase in melanocytes and a statistically significant increase in melanocytic atypia (p < .0001) and epidermal melanin (p < .0001). Other epidermal changes included reduced epidermal thickness (p < .01), more compact stratum corneum (p < .0001) and increased granular layer thickness (p < .0001) in the crow's feet skin. There was increased solar elastosis (p < .0001), dermal elastic tissue (p < .0001), melanophages (p < .0001), perivascular inflammation (p < .05) and perifollicular fibrosis (p < .01) but no change in the number of mast cells or dermal mucin in the photo exposed skin. Our data document quantitative differences in photoaged versus intrinsically aged facial skin and provides the groundwork for future studies to evaluate the efficacy of new treatments for photoaged skin.

  15. The intrinsic two-dimensional size of Sagittarius A*

    SciTech Connect

    Bower, Geoffrey C.; Markoff, Sera; Brunthaler, Andreas; Falcke, Heino; Law, Casey; Maitra, Dipankar; Clavel, M.; Goldwurm, A.; Morris, M. R.; Witzel, Gunther; Meyer, Leo; Ghez, A. M.

    2014-07-20

    We report the detection of the two-dimensional structure of the radio source associated with the Galactic Center black hole, Sagittarius A*, obtained from Very Long Baseline Array observations at a wavelength of 7 mm. The intrinsic source is modeled as an elliptical Gaussian with major-axis size 35.4 × 12.6 R{sub S} in position angle 95° east of north. This morphology can be interpreted in the context of both jet and accretion disk models for the radio emission. There is supporting evidence in large angular-scale multi-wavelength observations for both source models for a preferred axis near 95°. We also place a maximum peak-to-peak change of 15% in the intrinsic major-axis size over five different epochs. Three observations were triggered by detection of near infrared (NIR) flares and one was simultaneous with a large X-ray flare detected by NuSTAR. The absence of simultaneous and quasi-simultaneous flares indicates that not all high energy events produce variability at radio wavelengths. This supports the conclusion that NIR and X-ray flares are primarily due to electron excitation and not to an enhanced accretion rate onto the black hole.

  16. Ultrasonic resonant piezoelectric actuator with intrinsic torque measurement.

    PubMed

    Pott, Peter P; Matich, Sebastian; Schlaak, Helmut F

    2012-11-01

    Piezoelectric ultrasonic actuators are widely used in small-scale actuation systems, in which a closed-loop position control is usually utilized. To save an additional torque sensor, the intrinsic measurement capabilities of the piezoelectric material can be employed. To prove feasibility, a motor setup with clearly separated actuation for the friction and driving forces is chosen. The motor concept is based on resonant ultrasonic vibrations. To assess the effects of the direct piezoelectric effect, a capacitance bridge-type circuit has been selected. Signal processing is done by a measurement card with an integrated field-programmable gate array. The motor is used to drive a winch, and different torques are applied by means of weights to be lifted. Assessing the bridge voltage, a good proportionality to the applied torque of 1.47 mV/mN·m is shown. A hysteresis of 1% has been determined. The chosen motor concept is useful for intrinsic torque measurement. However, it provides drawbacks in terms of limited mechanical performance, wear, and thermal losses because of the soft piezoelectric material. Future work will comprise the application of the method to commercially available piezoelectric actuators as well as the implementation of the measurement circuit in an embedded system. PMID:23192814

  17. Tractography from HARDI using an intrinsic unscented Kalman filter.

    PubMed

    Cheng, Guang; Salehian, Hesamoddin; Forder, John R; Vemuri, Baba C

    2015-01-01

    A novel adaptation of the unscented Kalman filter (UKF) was recently introduced in literature for simultaneous multitensor estimation and fiber tractography from diffusion MRI. This technique has the advantage over other tractography methods in terms of computational efficiency, due to the fact that the UKF simultaneously estimates the diffusion tensors and propagates the most consistent direction to track along. This UKF and its variants reported later in literature however are not intrinsic to the space of diffusion tensors. Lack of this key property can possibly lead to inaccuracies in the multitensor estimation as well as in the tractography. In this paper, we propose a novel intrinsic unscented Kalman filter (IUKF) in the space of diffusion tensors which are symmetric positive definite matrices, that can be used for simultaneous recursive estimation of multitensors and propagation of directional information for use in fiber tractography from diffusion weighted MR data. In addition to being more accurate, IUKF retains all the advantages of UKF mentioned above. We demonstrate the accuracy and effectiveness of the proposed method via experiments publicly available phantom data from the fiber cup-challenge (MICCAI 2009) and diffusion weighted MR scans acquired from human brains and rat spinal cords.

  18. Plastic-casting intrinsic-surface unique identifier (tag)

    SciTech Connect

    Palm, R.G.; De Volpi, A.

    1995-04-01

    This report describes the development of an authenticated intrinsic-surf ace tagging method for unique- identification of controlled items. Although developed for control of items limited by an arms control treaty, this method has other potential applications to keep track of critical or high-value items. Each tag (unique-identifier) consists of the intrinsic, microscopic surface topography of a small designated area on a controlled item. It is implemented by making a baseline plastic casting of the designated tag area and usually placing a cover (for example, a bar-code label) over this area to protect the surface from environmental alteration. The plastic casting is returned to a laboratory and prepared for high-resolution scanning electron microscope imaging. Several images are digitized and stored for use as a standard for authentication of castings taken during future inspections. Authentication is determined by numerically comparing digital images. Commercially available hardware and software are used for this tag. Tag parameters are optimized, so unique casting images are obtained from original surfaces, and images obtained from attempted duplicate surfaces are detected. This optimization uses the modulation transfer function, a first principle of image analysis, to determine the parameters. Surface duplication experiments confirmed the optimization.

  19. High-Speed Intrinsic Dissolution Rate in One Minute Using the Single-Particle Intrinsic Dissolution Rate Method.

    PubMed

    Svanbäck, Sami; Ehlers, Henrik; Antikainen, Osmo; Yliruusi, Jouko

    2015-11-01

    Intrinsic dissolution rate (IDR) has traditionally been determined from a constant surface area of a substance. Here we present an optofluidic single-particle intrinsic dissolution rate (SIDR) method, by means of which real-time determination of IDR from continuously changing effective surface areas of dissolving individual microparticles, is possible. The changing surface area of the individual microparticles is characterized through continuous random orientation 3D particle morphology characterization during the dissolution process. Using noninvasive optical monitoring and nonspecific image analysis, we determined IDRs of a diverse set of substances from individual pure-substance microparticles (14-747 μg) with an average relative standard deviation of 9.4%. A linear fit between SIDR and literature equilibrium solubility values (R(2) = 0.999) was achieved and kinetic solubility equivalent SIDRs were obtained, for all substances, in as little as 1 min. Such miniaturized methods could become valuable tools in drug discovery, by providing resource sparing higher quality data acquisition means to replace current high-throughput solubility methods.

  20. Brain mechanical property measurement using MRE with intrinsic activation

    NASA Astrophysics Data System (ADS)

    Weaver, John B.; Pattison, Adam J.; McGarry, Matthew D.; Perreard, Irina M.; Swienckowski, Jessica G.; Eskey, Clifford J.; Lollis, S. Scott; Paulsen, Keith D.

    2012-11-01

    Many pathologies alter the mechanical properties of tissue. Magnetic resonance elastography (MRE) has been developed to noninvasively characterize these quantities in vivo. Typically, small vibrations are induced in the tissue of interest with an external mechanical actuator. The resulting displacements are measured with phase contrast sequences and are then used to estimate the underlying mechanical property distribution. Several MRE studies have quantified brain tissue properties. However, the cranium and meninges, especially the dura, are very effective at damping externally applied vibrations from penetrating deeply into the brain. Here, we report a method, termed ‘intrinsic activation’, that eliminates the requirement for external vibrations by measuring the motion generated by natural blood vessel pulsation. A retrospectively gated phase contrast MR angiography sequence was used to record the tissue velocity at eight phases of the cardiac cycle. The velocities were numerically integrated via the Fourier transform to produce the harmonic displacements at each position within the brain. The displacements were then reconstructed into images of the shear modulus based on both linear elastic and poroelastic models. The mechanical properties produced fall within the range of brain tissue estimates reported in the literature and, equally important, the technique yielded highly reproducible results. The mean shear modulus was 8.1 kPa for linear elastic reconstructions and 2.4 kPa for poroelastic reconstructions where fluid pressure carries a portion of the stress. Gross structures of the brain were visualized, particularly in the poroelastic reconstructions. Intra-subject variability was significantly less than the inter-subject variability in a study of six asymptomatic individuals. Further, larger changes in mechanical properties were observed in individuals when examined over time than when the MRE procedures were repeated on the same day. Cardiac pulsation

  1. STELLAR LOCI. I. METALLICITY DEPENDENCE AND INTRINSIC WIDTHS

    SciTech Connect

    Yuan, Haibo; Liu, Xiaowei; Xiang, Maosheng; Huang, Yang; Chen, Bingqiu E-mail: x.liu@pku.edu.cn

    2015-02-01

    Stellar loci are widely used for selection of interesting outliers, reddening determinations, and calibrations. However, until now, the dependence of stellar loci on metallicity has not been fully explored, and their intrinsic widths are unclear. In this paper, by combining the spectroscopic and recalibrated imaging data of the Sloan Digital Sky Survey (SDSS) Stripe 82, we have built a large, clean sample of dwarf stars with accurate colors and well-determined metallicities to investigate the metallicity dependence and intrinsic widths of the SDSS stellar loci. Typically, 1 dex decrease in metallicity causes 0.20 and 0.02 mag decrease in colors u – g and g – r and 0.02 and 0.02 mag increase in colors r – i and i – z, respectively. The variations are larger for metal-rich stars than for metal-poor ones, and larger for F/G/K stars than for A/M ones. Using the sample, we have performed two-dimensional polynomial fitting to the u – g, g – r, r – i, and i – z colors as a function of color g – i and metallicity [Fe/H]. The residuals, at the level of 0.029, 0.008, 0.008, and 0.011 mag for the u – g, g – r, r – i, and i – z colors, respectively, can be fully accounted for by the photometric errors and metallicity uncertainties, suggesting that the intrinsic widths of the loci are at maximum a few millimagnitudes. The residual distributions are asymmetric, revealing that a significant fraction of stars are binaries. In a companion paper, we will present an unbiased estimate of the binary fraction for field stars. Other potential applications of the metallicity-dependent stellar loci are briefly discussed.

  2. Interdiffusion and Intrinsic Diffusion in the Mg-Al System

    SciTech Connect

    Brennan, Sarah; Bermudez, Katrina; Sohn, Yong Ho; Kulkarni, Nagraj S

    2012-01-01

    Solid-to-solid diffusion couples were assembled and annealed to examine the diffusion between pure Mg (99.96%) and Al (99.999%). Diffusion anneals were carried out at 300 , 350 , and 400 C for 720, 360, and 240 hours, respectively. Optical and scanning electron microscopes were utilized to identify the formation of the intermetallic phases, -Al12Mg17 and -Al3Mg2 and absence of the -phase in the diffusion couples. Thicknesses of the -Al12Mg17 and -Al3Mg2 phases were measured and the parabolic growth constants were calculated to determine the activation energies for the growth, 165 and 86 KJ/mole, respectively. Concentration profiles were determined with electron microprobe analysis using pure elemental standards. Composition-dependent interdiffusion coefficients in Mg-solid solution, -Al12Mg17 and - Al3Mg2 and Al-solid solutions were calculated based on the Boltzmann-Matano analysis. Average effective interdiffusion coefficients for each phase were also calculated, and the magnitude was the highest for the -Al3Mg2 phase, followed by -Al12Mg17, Al-solid solution and Mg-solid solution. Intrinsic diffusion coefficients based on Huemann s analysis (e.g., marker plane) were determined for the ~38 at.% Mg in the -Al3Mg2 phase. Activation energies and the pre-exponential factors for the inter- and intrinsic diffusion coefficients were calculated for the temperature range examined. The -Al3Mg2 phase was found to have the lowest activation energies for growth and interdiffusion among all four phases studied. At the marker location in the -Al3Mg2 phase, the intrinsic diffusion of Al was found to be faster than that of Mg. Extrapolations of the impurity diffusion coefficients in the terminal solid solutions were made and compared to the available self- and impurity diffusion data from literature. Thermodynamic factor, tracer diffusion coefficients and atomic mobilities at the marker plane composition were approximated using available literature values of Mg activity in the -Al

  3. Intrinsic sex-specific differences in microvascular endothelial cell phosphodiesterases

    PubMed Central

    Bingaman, Susan; Huxley, Virginia H.

    2010-01-01

    The importance of gonadal hormones in the regulation of vascular function has been documented. An alternate and essential contribution of the sex chromosomes to sex differences in vascular function is poorly understood. We reported previously sex differences in microvessel permeability (Ps) responses to adenosine that were mediated by the cAMP signaling pathway (Wang J, PhD thesis, 2005; Wang J and Huxley V, Proceedings of the VIII World Congress of Microcirculation, 2007; Wang J and Huxley VH, Am J Physiol Heart Circ Physiol 291: H3094–H3105, 2006). The two cyclic nucleotides, cAMP and cGMP, central to the regulation of vascular barrier integrity, are hydrolyzed by phosphodiesterases (PDE). We hypothesized that microvascular endothelial cells (EC) would retain intrinsic and inheritable sexually dimorphic genes with respect to the PDEs modulating EC barrier function. Primary cultured microvascular EC from skeletal muscles isolated from male and female rats, respectively, were used. SRY (a sex-determining region Y gene) mRNA expression was observed exclusively in male, not female, cells. The predominant isoform among PDE1–5, present in both XY and XX EC, was PDE4. Expression mRNA levels of PDE1A (male > female) and PDE3B (male < female) were sex dependent; PDE2A, PDE4D, and PDE5A were sex independent. Barrier function, Ps, was determined from measures of albumin flux across confluent primary cultured microvessel XY and XX EC monolayers. Consistent with intact in situ microvessels, basal monolayer Ps did not differ between XY (1.7 ± 0.2 × 10−6 cm/s; n = 8) and XX (1.8 ± 0.1 × 10−6 cm/s; n = 10) EC. Cilostazol, a PDE3 inhibitor, reduced (11%, P < 0.05) Ps in XX, not XY, cells. These findings demonstrate the presence and maintenance of intrinsic sex-related differences in gene expression and cellular phenotype by microvascular EC in a gonadal-hormone-free environment. Furthermore, intrinsic cell-sex likely contributes significantly to sexual dimorphism in

  4. Electrodynamics and intrinsic Josephson effects in multi-gap superconductors

    NASA Astrophysics Data System (ADS)

    Koyama, Tomio; Ota, Yukihiro; Machida, Masahiko

    2010-11-01

    We develop a theory for the Josephson effects in 2-gap intrinsic Josephson junction stacks (IJJ's). The coupled dynamical equations for the phase differences are derived from the low-energy effective Lagrangian. The equations can describe the longitudinal Josephson plasma and the Josephson-Leggett (JL) mode propagating in the direction perpendicular to the junctions. Numerical results for the I - V characteristics are presented. The I - V characteristics shows multiple-branch structure similar to that in Bi-2212 IJJ's. When the Josephson frequency is approached to the JL mode frequency in non-uniform voltage branches, the JL mode is resonantly excited. At the resonant voltage a step-like structure appears in the I - V curves in low-voltage branches.

  5. MQT observation in Bi2212 intrinsic Josephson junctions

    NASA Astrophysics Data System (ADS)

    Kashiwaya, Satoshi; Matsumoto, Tetsuro; Kashiwaya, Hiromi; Shibata, Hajime; Eisaki, Hiroshi; Yoshida, Yoshiyuki; Kawabata, Shiro; Tanaka, Yukio

    2007-09-01

    The quantum dynamics of Bi 2Sr 2CaCu 2O 8+ δ intrinsic Josephson junctions (IJJ’s) is studied based on the escape rate measurements. The saturations observed in the escape temperature and the width of the switching current below 0.45 K (= T∗) indicate the transition of the switching mechanism from the thermal activation to the macroscopic quantum tunneling at T∗. It is shown that most of the switching properties are consistently explained in terms of the underdamped Josephson junction with quality factor of about 70 in spite of possible damping due to d-wave superconductivity. The present result gives the upper limit of the dissipation of IJJ’s.

  6. Intrinsic electric dipole moments of paramagnetic atoms: rubidium and cesium.

    PubMed

    Nataraj, H S; Sahoo, B K; Das, B P; Mukherjee, D

    2008-07-18

    The electric dipole moment (EDM) of paramagnetic atoms is sensitive to the intrinsic EDM contribution from that of its constituent electrons and a scalar-pseudoscalar (S-PS) electron-nucleus interaction. The electron EDM and the S-PS contributions to the EDMs of these atoms scale as approximately Z;{3}. Thus, the heavy paramagnetic atoms will exhibit large EDM enhancement factors. However, the sizes of the couplings are so small that they are of interest of high precision atomic experiments. In this work we have computed the EDM enhancement factors of the ground states of Rb and Cs due to both the electron EDM and the S-PS EDM using the relativistic coupled-cluster theory. The importance of determining precise ab initio enhancement factors and experimental results of atomic EDMs in deducing a reliable limit on the electron EDM is emphasized.

  7. Intrinsic fluctuations and driven response of insect swarms

    NASA Astrophysics Data System (ADS)

    Ni, Rui; Puckett, James G.; Dufresne, Eric R.; Ouellette, Nicholas T.

    2015-03-01

    Much of our understanding of collective behaviour in social animals comes from passive observations of animal groups. To understand the group dynamics fully, however, we must also characterize the response of animal aggregations to disturbances. Using three-dimensional particle tracking, we study both the intrinsic fluctuations of laboratory swarms of the non-biting midge Chironomus riparius and the response of the swarms to controlled external perturbations: the amplitude-modulated sound of male midge wingbeats. Although these perturbations have an insignificant effect on the behavior of individuals, we find that they can have a strong impact on the collective movement. Intriguingly, the response of the swarm is similar reminiscent to of that of a passive equilibrium system to an external driving force, with microscopic fluctuations underlying combining to produce a macroscopic linear response over a wide range of driving frequencies.

  8. Intrinsic bioremediation potential of a chronically polluted marine coastal area.

    PubMed

    Catania, Valentina; Santisi, Santina; Signa, Geraldina; Vizzini, Salvatrice; Mazzola, Antonio; Cappello, Simone; Yakimov, Michail M; Quatrini, Paola

    2015-10-15

    A microbiological survey of the Priolo Bay (eastern coast of Sicily, Ionian Sea), a chronically polluted marine coastal area, was carried out in order to discern its intrinsic bioremediation potential. Microbiological analysis, 16S rDNA-based DGGE fingerprinting and PLFAs analysis were performed on seawater and sediment samples from six stations on two transects. Higher diversity and variability among stations was detected by DGGE in sediment than in water samples although seawater revealed higher diversity of culturable hydrocarbon-degrading bacteria. The most polluted sediment hosted higher total bacterial diversity and higher abundance and diversity of culturable HC degraders. Alkane- and PAH-degrading bacteria were isolated from all stations and assigned to Alcanivorax, Marinobacter, Thalassospira, Alteromonas and Oleibacter (first isolation from the Mediterranean area). High total microbial diversity associated to a large selection of HC degraders is believed to contribute to natural attenuation of the area, provided that new contaminant contributions are avoided. PMID:26248825

  9. Intrinsic common noise in a system of two coupled Brusselators

    NASA Astrophysics Data System (ADS)

    Nandi, Amitabha; Lindner, Benjamin

    2010-10-01

    We investigate effects of coupling two chemical subsystems through diffusion of chemical species. We consider the Langevin description of the actual microscopic dynamics and show that diffusive coupling gives rise to a common noise term along with the deterministic interaction. As a model example, we study two diffusively coupled Brusselator systems. By numerical Langevin simulations, we inspect the effect of the common noise term on the total correlation between the two Brusselators; we also verify the validity of the Langevin approach by comparison to simulations of the more accurate master equation. The intrinsic common noise has its strongest effect for the Brusselator dynamics operating at a stable fixed point far from the Hopf bifurcation; in this case, the common noise reduces the correlation of the Brusselators significantly. We also show that for specific parameter sets the covariance between the systems is maximized (or minimized) at a finite system size.

  10. First Intrinsic Anisotropy Observations With the Cosmic Background Imager

    NASA Technical Reports Server (NTRS)

    Padin, S.; Cartwright, J. K.; Mason, B. S.; Pearson, T. J.; Readhead, A. C. S.; Shepherd, M. C.; Sievers, J.; Udomprasert, P. S.; Holzapfel, W. L.; Myers, S. T.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    We present the first results of observations of the intrinsic anisotropy of the cosmic microwave background radiation with the Cosmic Background Imager from a site at 5080 in altitude in northern Chile. Our observations show a sharp decrease in C_l in the range l = 400 - 1500. Such a decrease in power at high l is one of the fundamental predictions of the standard cosmological model, and these are the first observations which cover a broad enough 1-range to show this decrease in a single experiment. The power, C_l, at l approximately 600 is higher than measured by Boomerang and Maxima, with the differences being significant at the 2.7sigma and 1.9sigma levels, respectively. The C_l we have measured enable us to place limits on the density parameter, Omega(tot) <= 0.4 or Omega(tot) >= 0.7 (90% confidence).

  11. Intrinsic Fabry-Perot optical fiber sensors and their multiplexing

    DOEpatents

    Wang, Anbo

    2007-12-11

    An intrinsic Fabry-Perot optical sensor includes a thin film sandwiched between two fiber ends. When light is launched into the fiber, two reflections are generated at the two fiber/thin film interfaces due to a difference in refractive indices between the fibers and the film, giving rise to the sensor output. In another embodiment, a portion of the cladding of a fiber is removed, creating two parallel surfaces. Part of the evanescent fields of light propagating in the fiber is reflected at each of the surfaces, giving rise to the sensor output. In a third embodiment, the refractive index of a small portion of a fiber is changed through exposure to a laser beam or other radiation. Interference between reflections at the ends of the small portion give rise to the sensor output. Multiple sensors along a single fiber are multiplexed using an optical time domain reflectometry method.

  12. Intrinsic optical signal imaging of retinal physiology: a review.

    PubMed

    Yao, Xincheng; Wang, Benquan

    2015-09-01

    Intrinsic optical signal (IOS) imaging promises to be a noninvasive method for high-resolution examination of retinal physiology, which can advance the study and diagnosis of eye diseases. While specialized optical instruments are desirable for functional IOS imaging of retinal physiology, in depth understanding of multiple IOS sources in the complex retinal neural network is essential for optimizing instrument designs. We provide a brief overview of IOS studies and relationships in rod outer segment suspensions, isolated retinas, and intact eyes. Recent developments of line-scan confocal and functional optical coherence tomography (OCT) instruments have allowed in vivo IOS mapping of photoreceptor physiology. Further improvements of the line-scan confocal and functional OCT systems may provide a feasible solution to pursue functional IOS mapping of human photoreceptors. Some interesting IOSs have already been detected in inner retinal layers, but better development of the IOS instruments and software algorithms is required to achieve optimal physiological assessment of inner retinal neurons.

  13. Intrinsic optical bistability in a strongly driven Rydberg ensemble

    NASA Astrophysics Data System (ADS)

    de Melo, Natalia R.; Wade, Christopher G.; Šibalić, Nikola; Kondo, Jorge M.; Adams, Charles S.; Weatherill, Kevin J.

    2016-06-01

    We observe and characterize intrinsic optical bistability in a dilute Rydberg vapor. The bistability is characterized by sharp jumps between states of low and high Rydberg occupancy with jump-up and -down positions displaying hysteresis depending on the direction in which the control parameter is changed. We find that the shift in frequency of the jump point scales with the fourth power of the principal quantum number. Also, the width of the hysteresis window increases with increasing principal quantum number, before reaching a peak and then closing again. The experimental results are consistent with predictions from a simple theoretical model based on semiclassical Maxwell-Bloch equations including the effects of interaction-induced broadening and level shifts. These results provide insight into the dynamics of driven dissipative systems.

  14. Intrinsic and extrinsic curvatures in Finsler esque spaces

    NASA Astrophysics Data System (ADS)

    Kothawala, Dawood

    2014-12-01

    We consider metrics related to each other by functionals of a scalar field and it's gradient , and give transformations of some key geometric quantities associated with such metrics. Our analysis provides useful and elegant geometric insights into the roles of conformal and non-conformal metric deformations in terms of intrinsic and extrinsic geometry of -foliations. As a special case, we compare conformal and disformal transforms to highlight some non-trivial scaling differences. We also study the geometry of equi-geodesic surfaces formed by points at constant geodesic distance from a fixed point , and apply our results to a specific disformal geometry based on which was recently shown to arise in the context of spacetime with a minimal length.

  15. Intrinsic bioremediation potential of a chronically polluted marine coastal area.

    PubMed

    Catania, Valentina; Santisi, Santina; Signa, Geraldina; Vizzini, Salvatrice; Mazzola, Antonio; Cappello, Simone; Yakimov, Michail M; Quatrini, Paola

    2015-10-15

    A microbiological survey of the Priolo Bay (eastern coast of Sicily, Ionian Sea), a chronically polluted marine coastal area, was carried out in order to discern its intrinsic bioremediation potential. Microbiological analysis, 16S rDNA-based DGGE fingerprinting and PLFAs analysis were performed on seawater and sediment samples from six stations on two transects. Higher diversity and variability among stations was detected by DGGE in sediment than in water samples although seawater revealed higher diversity of culturable hydrocarbon-degrading bacteria. The most polluted sediment hosted higher total bacterial diversity and higher abundance and diversity of culturable HC degraders. Alkane- and PAH-degrading bacteria were isolated from all stations and assigned to Alcanivorax, Marinobacter, Thalassospira, Alteromonas and Oleibacter (first isolation from the Mediterranean area). High total microbial diversity associated to a large selection of HC degraders is believed to contribute to natural attenuation of the area, provided that new contaminant contributions are avoided.

  16. Intrinsic electrical conductivity of nanostructured metal-organic polymer chains.

    PubMed

    Hermosa, Cristina; Vicente Álvarez, Jose; Azani, Mohammad-Reza; Gómez-García, Carlos J; Fritz, Michelle; Soler, Jose M; Gómez-Herrero, Julio; Gómez-Navarro, Cristina; Zamora, Félix

    2013-01-01

    One-dimensional conductive polymers are attractive materials because of their potential in flexible and transparent electronics. Despite years of research, on the macro- and nano-scale, structural disorder represents the major hurdle in achieving high conductivities. Here we report measurements of highly ordered metal-organic nanoribbons, whose intrinsic (defect-free) conductivity is found to be 10(4) S m(-1), three orders of magnitude higher than that of our macroscopic crystals. This magnitude is preserved for distances as large as 300 nm. Above this length, the presence of structural defects (~ 0.5%) gives rise to an inter-fibre-mediated charge transport similar to that of macroscopic crystals. We provide the first direct experimental evidence of the gapless electronic structure predicted for these compounds. Our results postulate metal-organic molecular wires as good metallic interconnectors in nanodevices.

  17. Intrinsic peroxidase-like activity of ferromagnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Gao, Lizeng; Zhuang, Jie; Nie, Leng; Zhang, Jinbin; Zhang, Yu; Gu, Ning; Wang, Taihong; Feng, Jing; Yang, Dongling; Perrett, Sarah; Yan, Xiyun

    2007-09-01

    Nanoparticles containing magnetic materials, such as magnetite (Fe3O4), are particularly useful for imaging and separation techniques. As these nanoparticles are generally considered to be biologically and chemically inert, they are typically coated with metal catalysts, antibodies or enzymes to increase their functionality as separation agents. Here, we report that magnetite nanoparticles in fact possess an intrinsic enzyme mimetic activity similar to that found in natural peroxidases, which are widely used to oxidize organic substrates in the treatment of wastewater or as detection tools. Based on this finding, we have developed a novel immunoassay in which antibody-modified magnetite nanoparticles provide three functions: capture, separation and detection. The stability, ease of production and versatility of these nanoparticles makes them a powerful tool for a wide range of potential applications in medicine, biotechnology and environmental chemistry.

  18. Nonlinear intrinsic variables and state reconstruction in multiscale simulations

    SciTech Connect

    Dsilva, Carmeline J.; Talmon, Ronen Coifman, Ronald R.; Rabin, Neta; Kevrekidis, Ioannis G.

    2013-11-14

    Finding informative low-dimensional descriptions of high-dimensional simulation data (like the ones arising in molecular dynamics or kinetic Monte Carlo simulations of physical and chemical processes) is crucial to understanding physical phenomena, and can also dramatically assist in accelerating the simulations themselves. In this paper, we discuss and illustrate the use of nonlinear intrinsic variables (NIV) in the mining of high-dimensional multiscale simulation data. In particular, we focus on the way NIV allows us to functionally merge different simulation ensembles, and different partial observations of these ensembles, as well as to infer variables not explicitly measured. The approach relies on certain simple features of the underlying process variability to filter out measurement noise and systematically recover a unique reference coordinate frame. We illustrate the approach through two distinct sets of atomistic simulations: a stochastic simulation of an enzyme reaction network exhibiting both fast and slow time scales, and a molecular dynamics simulation of alanine dipeptide in explicit water.

  19. Disentangling intrinsic ultrafast excited-state dynamics of cytosine tautomers.

    PubMed

    Ho, Jr-Wei; Yen, Hung-Chien; Chou, Wei-Kuang; Weng, Chih-Nan; Cheng, Li-Hao; Shi, Hui-Qi; Lai, Szu-Hsueh; Cheng, Po-Yuan

    2011-08-01

    Gas-phase ultrafast excited-state dynamics of cytosine, 1-methylcytosine, and 5-fluorocytosine were investigated in molecular beams using femtosecond pump-probe photoionization spectroscopy to identify the intrinsic dynamics of the major cytosine tautomers. The results indicate that, upon photoexcitation in the first absorption band, the cytosine enol tautomer exhibits a significantly longer excited-state lifetime than its keto and imino counterparts. The initially excited states of the cytosine keto and imino tautomers decay with sub-picosecond dynamics for excitation wavelengths shorter than 300 nm, whereas that of the cytosine enol tautomer decays with time constants ranging from 3 to 45 ps for excitation between 260 and 285 nm.

  20. Restoration of pinch in intrinsic muscles of the hand.

    PubMed

    Lee, Steve K; Wisser, Jamie R

    2012-02-01

    The primary intrinsic muscles responsible for key and tip pinch are the adductor pollicis, first dorsal interosseous and flexor pollicis brevis muscles. Numerous conditions can lead to their dysfunction. Non-operative treatment consists of exercises of the compensating extensor pollicis longus and flexor pollicis longus muscles and use of adaptive devices, such as larger grips. Operative treatments include tendon transfers and joint fusions. The most common tendon transfer procedures include transfering of the extensor carpi radialis brevis to the adductor pollicis muscle or transfering of the abductor pollicis longus to the first dorsal interosseous muscle. Both require use of extension tendon grafts. In cases of joint instability or arthrosis, arthrodesis of the thumb and index finger MP or IP joints, alone or in combination, may be indicated. PMID:22117923