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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. The relationship between motivational structure, sense of control, intrinsic motivation and university students' alcohol consumption.

    PubMed

    Shamloo, Zohreh Sepehri; Cox, W Miles

    2010-02-01

    The aim of this study was to determine how sense of control and intrinsic motivation are related to university students' motivational structure and alcohol consumption. Participants were 94 university students who completed the Personal Concerns Inventory, Shapiro Control Inventory, Helplessness Questionnaire, Intrinsic-Extrinsic Aspirations Scale, and Alcohol Use Questionnaire. Results showed that sense of control and intrinsic motivation were positively correlated with adaptive motivation and negatively correlated with alcohol consumption. Mediational analyses indicated that adaptive motivation fully mediated the relationship between sense of control/intrinsic motivation and alcohol consumption. PMID:19836901

  4. Intrinsic predictive factors for ankle sprain in active university students: a prospective study.

    PubMed

    de Noronha, M; França, L C; Haupenthal, A; Nunes, G S

    2013-10-01

    The ankle is the joint most affected among the sports-related injuries. The current study investigated whether certain intrinsic factors could predict ankle sprains in active students. The 125 participants were submitted to a baseline assessment in a single session were then followed-up for 52 weeks regarding the occurrence of sprain. The baseline assessment were performed in both ankles and included the questionnaire Cumberland ankle instability tool - Portuguese, the foot lift test, dorsiflexion range of motion, Star Excursion Balance Test (SEBT), the side recognition task, body mass index, and history of previous sprain. Two groups were used for analysis: one with those who suffered an ankle sprain and the other with those who did not suffer an ankle sprain. After Cox regression analysis, participants with history of previous sprain were twice as likely to suffer subsequent sprains [hazard ratio (HR) 2.21 and 95% confidence interval (CI) 1.07-4.57] and people with better performance on the SEBT in the postero-lateral (PL) direction were less likely to suffer a sprain (HR 0.96 and 95% CI 0.92-0.99). History of previous sprain was the strongest predictive factor and a weak performance on SEBT PL was also considered a predictive factor for ankle sprains. PMID:22260485

  5. Testing cosmology from fundamental considerations: Is the Friedmann universe intrinsically flat

    NASA Astrophysics Data System (ADS)

    Mitra, Abhas

    2014-02-01

    Recently Melia and Shevchuk (Mon Not R Astron Soc 419:2579,2012) (MS) have proposed the so-called cosmology where the "Gravitational Horizon" of the universe is equal to the distance travelled by light since "Big Bang". Here we would like to see whether the basic claim is correct or not because MS have not given any cogent derivation for the same. Essentially we will compare the twin expressions for the Einstein energy momentum complex (EMC) of the Friedmann universe obtained by using an appropriate superpotential and also by a direct method. To enable a meaningful comparison of the twin expressions, both are computed by using the same quasi-Cartesian coordinates. We however do not claim that Einstein EMC is superior to many other routes of defining EM of a self-gravitating system. In fact, for static isolated spherical syatems, the idea of a coordinate independent field energy of Lynden-Bell and Katz (Mon Not R Astron Soc 213:21, 1985) might be quite physically significant. Yet, here, we use Einstein EMC because (i) our system is non-static and not isolated one (ii) our primary aim is not find any absolute value of EM, and, finally, (iii) only Einstein pseudo-tensor offers equivalent twin expressions for EM which one can be equated irrespective of any physical significance. Following such comparison of equivalent twin expressions of Einstein energy, we find an exact proof as to why Friedmann universe must be spatially flat even though, mathematically one can conceive of curved spaces in any dimension. Additionally, it follows that, apparently, the scale factor as insisted by proposition. Nonetheless, because of close similarity of this form, , with the (vacuum) Milne metric, and also because of implied unphysical equation of state, cosmology is unlikely to represent the physical universe.

  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. PMID:27610091

  7. 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.

  8. 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.

  9. Relationships Between Goal Orientation, Motivational Climate and Perceived Ability with Intrinsic Motivation and Performance in Physical Education University Students

    NASA Astrophysics Data System (ADS)

    Shafizadeh, Mohsen

    The purposes of the present investigation were to study the relationships between goal orientation, motivational climate and perceived ability with intrinsic motivation, behavioral patterns and performance. One hundred and sixty three males and females students from physical education classes selected and completed the Task and Ego Orientation, Intrinsic Motivation, Perceived Motivational Climate in Sport and Perceived Ability questionnaires. The results of structural equation models (SEM) and correlation coefficients showed that there are significant correlations between ego-orientation, task-orientation and mastery climate with intrinsic motivation (R = 0.58,X2 = 103.72, p< 0.0001) and between intrinsic motivation with trend, effort and performance (R = 0.42, X2 = 37.85, p< 0.0001). In conclusion, to increase trend and effort of students in sport classes their achievement goal orientations should to considered and increasing the intrinsic motivation, perceived ability and mastery climate have a facilitative role.

  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. 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.

  12. 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).

  13. 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.

  14. n-dimensional Statistical Inverse Graphical Hydraulic Test Simulator

    Energy Science and Technology Software Center (ESTSC)

    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

  15. Intrinsic time quantum geometrodynamics

    NASA Astrophysics Data System (ADS)

    Ita, Eyo Eyo; Soo, Chopin; Yu, Hoi-Lai

    2015-08-01

    Quantum geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl curvature hypothesis, and thermodynamic and gravitational "arrows of time" point in the same direction. Ricci scalar potential corresponding to Einstein's general relativity emerges as a zero-point energy contribution. A new set of fundamental commutation relations without Planck's constant emerges from the unification of gravitation and quantum mechanics.

  16. 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.

  17. Intrinsic Motivation and Self-esteem in Traditional and Mature Students at a Post-1992 University in the North-east of England.

    ERIC Educational Resources Information Center

    Murphy, Helen; Roopchand, Naomi

    2003-01-01

    Presents a study that focuses on the relationship between intrinsic motivation towards learning and self-esteem in traditional and mature students. Examines the students' learning approaches. Uses the Intrinsic Motivation towards Learning Questionnaire and the Rosenberg Global Self-Esteem Questionnaire. (CMK)

  18. 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.

  19. Secure N-dimensional simultaneous dense coding and applications

    NASA Astrophysics Data System (ADS)

    Situ, H.; Qiu, D.; Mateus, P.; Paunković, N.

    2015-12-01

    Simultaneous dense coding (SDC) guarantees that Bob and Charlie simultaneously receive their respective information from Alice in their respective processes of dense coding. The idea is to use the so-called locking operation to “lock” the entanglement channels, thus requiring a joint unlocking operation by Bob and Charlie in order to simultaneously obtain the information sent by Alice. We present some new results on SDC: (1) We propose three SDC protocols, which use different N-dimensional entanglement (Bell state, W state and GHZ state). (2) Besides the quantum Fourier transform, two new locking operators are introduced (the double controlled-NOT operator and the SWAP operator). (3) In the case that spatially distant Bob and Charlie have to finalize the protocol by implementing the unlocking operation through communication, we improve our protocol’s fairness, with respect to Bob and Charlie, by implementing the unlocking operation in series of steps. (4) We improve the security of SDC against the intercept-resend attack. (5) We show that SDC can be used to implement a fair contract signing protocol. (6) We also show that the N-dimensional quantum Fourier transform can act as the locking operator in simultaneous teleportation of N-level quantum systems.

  20. Intrinsic n

    SciTech Connect

    Zhang, S. B.; Wei, S.-H.; Zunger, Alex

    2001-02-15

    ZnO typifies a class of materials that can be doped via native defects in only one way: either n type or p type. We explain this asymmetry in ZnO via a study of its intrinsic defect physics, including Zn{sub O}, Zn{sub i}, V{sub O}, O{sub i}, and V{sub Zn} and n-type impurity dopants, Al and F. We find that ZnO is n type at Zn-rich conditions. This is because (i) the Zn interstitial, Zn{sub i}, is a shallow donor, supplying electrons; (ii) its formation enthalpy is low for both Zn-rich and O-rich conditions, so this defect is abundant; and (iii) the native defects that could compensate the n-type doping effect of Zn{sub i} (interstitial O, O{sub i}, and Zn vacancy, V{sub Zn}), have high formation enthalpies for Zn-rich conditions, so these ''electron killers'' are not abundant. We find that ZnO cannot be doped p type via native defects (O{sub i},V{sub Zn}) despite the fact that they are shallow (i.e., supplying holes at room temperature). This is because at both Zn-rich and O-rich conditions, the defects that could compensate p-type doping (V{sub O},Zn{sub i},Zn{sub O}) have low formation enthalpies so these ''hole killers'' form readily. Furthermore, we identify electron-hole radiative recombination at the V{sub O} center as the source of the green luminescence. In contrast, a large structural relaxation of the same center upon double hole capture leads to slow electron-hole recombination (either radiative or nonradiative) responsible for the slow decay of photoconductivity.

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

    PubMed

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

    2016-07-01

    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

  2. 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

  3. 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…

  4. 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.

  5. 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…

  6. 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.

  7. Intrinsic Solar System decoupling of a scalar-tensor theory with a universal coupling between the scalar field and the matter Lagrangian

    NASA Astrophysics Data System (ADS)

    Minazzoli, Olivier; Hees, Aurélien

    2013-08-01

    In this Communication, we present a class of Brans-Dicke-like theories with a universal coupling between the scalar field and the matter Lagrangian. We show this class of theories naturally exhibits a decoupling mechanism between the scalar field and matter. As a consequence, this coupling leads to almost the same phenomenology as general relativity in the Solar System: the trajectories of massive bodies and the light propagation differ from general relativity only at the second post-Newtonian order. Deviations from general relativity are beyond present detection capabilities. However, this class of theories predicts a deviation of the gravitational redshift at a level detectable by the future ACES and STE/QUEST missions.

  8. Pauli theorem in the description of n-dimensional spinors in the Clifford algebra formalism

    NASA Astrophysics Data System (ADS)

    Shirokov, D. S.

    2013-04-01

    We discuss a generalized Pauli theorem and its possible applications for describing n-dimensional (Dirac, Weyl, Majorana, and Majorana-Weyl) spinors in the Clifford algebra formalism. We give the explicit form of elements that realize generalizations of Dirac, charge, and Majorana conjugations in the case of arbitrary space dimensions and signatures, using the notion of the Clifford algebra additional signature to describe conjugations. We show that the additional signature can take only certain values despite its dependence on the matrix representation

  9. Real-time design of N-dimensional digital filters for image processing

    NASA Astrophysics Data System (ADS)

    Drynkin, Vladimir N.

    1995-12-01

    The main body of remote sensing data is obtained with the aid of optoelectronic and photographic devices. This data is usually referred to as the video information since it may be presented as images of terrestrial surface on a satellite track or an airway. This is the reason of increasing interest of specialists in the field of the remote sensing devices design to the methods of synthesis of optimal data processing hardware. The design of effective systems of the remote sensing data formation and transmission are impossible without using the state-of- the-art synthesis methods of digital image processing systems, taking account of a message source and their recipient characteristic properties. It is possible to take account of these characteristic properties only on the basis of optimal N-dimensional digital filtering. From this point of view the N-dimensional filter, used for video images filtering, becomes optimal only in the case of coincidence of the pass band region of its spatial frequency response (SFR) with the isoenergetic surface of the image spectrum with allowance for eyesight characteristics. In the light of the above the problem of N-dimensional digital filters design with the given pass band region configuration becomes actual. Incidentally the practicable interest presents first of all the methods, allowing with relatively low hardware expenses to design structures, from one part operating in the real time, and from the other -- approaching best of all the given characteristics. In this case it is necessary to ensure stability during their operation. In the following we shall present the results of the synthesis method development of N-dimensional digital filters with the guaranteed stability and the given pass band region configuration, realizing the image processing in the real time.

  10. General n-dimensional quadrature transform and its application to interferogram demodulation.

    PubMed

    Servin, Manuel; Quiroga, Juan Antonio; Marroquin, Jose Luis

    2003-05-01

    Quadrature operators are useful for obtaining the modulating phase phi in interferometry and temporal signals in electrical communications. In carrier-frequency interferometry and electrical communications, one uses the Hilbert transform to obtain the quadrature of the signal. In these cases the Hilbert transform gives the desired quadrature because the modulating phase is monotonically increasing. We propose an n-dimensional quadrature operator that transforms cos(phi) into -sin(phi) regardless of the frequency spectrum of the signal. With the quadrature of the phase-modulated signal, one can easily calculate the value of phi over all the domain of interest. Our quadrature operator is composed of two n-dimensional vector fields: One is related to the gradient of the image normalized with respect to local frequency magnitude, and the other is related to the sign of the local frequency of the signal. The inner product of these two vector fields gives us the desired quadrature signal. This quadrature operator is derived in the image space by use of differential vector calculus and in the frequency domain by use of a n-dimensional generalization of the Hilbert transform. A robust numerical algorithm is given to find the modulating phase of two-dimensional single-image closed-fringe interferograms by use of the ideas put forward. PMID:12747439

  11. 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…

  12. 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…

  13. 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)

  14. 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.

  15. 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.

  16. Intrinsic and extrinsic mortality reunited.

    PubMed

    Koopman, Jacob J E; Wensink, Maarten J; Rozing, Maarten P; van Bodegom, David; Westendorp, Rudi G J

    2015-07-01

    Intrinsic and extrinsic mortality are often separated in order to understand and measure aging. Intrinsic mortality is assumed to be a result of aging and to increase over age, whereas extrinsic mortality is assumed to be a result of environmental hazards and be constant over age. However, allegedly intrinsic and extrinsic mortality have an exponentially increasing age pattern in common. Theories of aging assert that a combination of intrinsic and extrinsic stressors underlies the increasing risk of death. Epidemiological and biological data support that the control of intrinsic as well as extrinsic stressors can alleviate the aging process. We argue that aging and death can be better explained by the interaction of intrinsic and extrinsic stressors than by classifying mortality itself as being either intrinsic or extrinsic. Recognition of the tight interaction between intrinsic and extrinsic stressors in the causation of aging leads to the recognition that aging is not inevitable, but malleable through the environment. PMID:25916736

  17. 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.

  18. Intrinsically Disordered Energy Landscapes

    PubMed Central

    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 -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

  19. 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

  20. Predicting intrinsic brain activity.

    PubMed

    Craddock, R Cameron; Milham, Michael P; LaConte, Stephen M

    2013-11-15

    Multivariate supervised learning methods exhibit a remarkable ability to decode externally driven sensory, behavioral, and cognitive states from functional neuroimaging data. Although they are typically applied to task-based analyses, supervised learning methods are equally applicable to intrinsic effective and functional connectivity analyses. The obtained models of connectivity incorporate the multivariate interactions between all brain regions simultaneously, which will result in a more accurate representation of the connectome than the ones available with standard bivariate methods. Additionally the models can be applied to decode or predict the time series of intrinsic brain activity of a region from an independent dataset. The obtained prediction accuracy provides a measure of the integration between a brain region and other regions in its network, as well as a method for evaluating acquisition and preprocessing pipelines for resting state fMRI data. This article describes a method for learning multivariate models of connectivity. The method is applied in the non-parametric prediction accuracy, influence, and reproducibility-resampling (NPAIRS) framework, to study the regional variation of prediction accuracy and reproducibility (Strother et al., 2002). The resulting spatial distribution of these metrics is consistent with the functional hierarchy proposed by Mesulam (1998). Additionally we illustrate the utility of the multivariate regression connectivity modeling method for optimizing experimental parameters and assessing the quality of functional neuroimaging data. PMID:23707580

  1. 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.

  2. 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

  3. 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.

  4. Intrinsic Feature Motion Tracking

    Energy Science and Technology Software Center (ESTSC)

    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

  5. 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

  6. 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.

  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. Sampling reconstruction of N-dimensional bandlimited images after multilinear filtering in fractional Fourier domain

    NASA Astrophysics Data System (ADS)

    Wei, Deyun; Li, Yuanmin

    2013-05-01

    This paper addresses the problem of multidimensional signal reconstruction from generalized samples in fractional Fourier domain including the deterministic case and the stochastic case. The generalized sampling expansion is investigated for the case where the fractional bandlimited input depends on N real variable, i.e., f(t)=f(t1,⋯,tN) and is used as a common input to a parallel bank of m independent N dimensional linear fractional Fourier filters Hα,k(u), k=1,⋯,m. For the deterministic input, the input is assumed to have its N dimensional fractional Fourier transform bandlimited to the frequency rang |ui|≤Ωi, for i=1,⋯,N. If m, the number of fractional Fourier filters, is written as a product of positive integers in the form m=m1m2⋯mN, and if the fractional bandlimited input f(t) is processed by fractional Fourier filter Hα,k(u)resulting m outputs gk(t), then f(t) can be reconstructed in terms of the samples gk(nT), each output being sampled at the identical rates of Ω1 csc α/m1π, Ω2 csc α/m2π,⋯, ΩN csc α/mNπ samples/second in t1,⋯,tN respectively. This contrasts with the rates of Ω1 csc α/π, Ω2 csc α/π,⋯, ΩN csc α/π in t1,⋯,tN needed for reconstruction of the unfiltered input f(t). Input sampling expansions in terms of samples of the output filters are given for both deterministic and stochastic inputs, the generalized sampling expansion for random input having the same form as for the deterministic case but interpreted in the mean-square sense. Our formulation and results are general and include derivative sampling and periodic nonuniform sampling in the fractional Fourier domain for multidimensional signals as special case. Finally, the potensional application of the multidimensional generalized sampling is presented to show the advantage of the theory. Especially, the application of multidimensional generalized sampling in the context of the image scaling about image super-resolution is

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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)

  14. 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.

  15. N-dimensional switch function for energy conservation in multiprocess reaction dynamics.

    PubMed

    Mogo, César; Brandão, João

    2016-06-15

    The MReaDy program was designed for studying Multiprocess Reactive Dynamic systems, that is, complex chemical systems involving different and concurrent reactions. It builds a global potential energy surface integrating a variety of potential energy surfaces, each one of them representing an elementary reaction expected to play a role in the chemical process. For each elementary reaction, energy continuity problems may happen in the transition between potential energy surfaces due to differences in the functional form for each of the fragments, especially if built by different authors. A N-dimensional switch function is introduced in MReaDy in order to overcome such a problem. As an example, results of a collision trajectory calculation for H2  + OH → H3 O are presented, showing smooth transition in the potential energy, leading to conservation in the total energy. Calculations for a hydrogen combustion system from 1000 K up to 4000 K shows a variation of 0.012% when compared to the total energy of the system. © 2016 Wiley Periodicals, Inc. PMID:26992438

  16. Stellar open clusters' membership probabilities: an N-dimensional geometrical approach

    NASA Astrophysics Data System (ADS)

    Sampedro, Laura; Alfaro, Emilio J.

    2016-04-01

    We present a new geometrical method aimed at determining the members of open clusters. The methodology estimates, in an N-dimensional space, the membership probabilities by means of the distances between every star and the cluster central overdensity. It can handle different sets of variables, which have to satisfy the simple condition of being more densely distributed for the cluster members than for the field stars (as positions, proper motions, radial velocities and/or parallaxes are). Unlike other existing techniques, this fact makes the method more flexible and so can be easily applied to different data sets. To quantify how the method identifies the cluster members, we design series of realistic simulations recreating sky regions in both position and proper motion subspaces populated by clusters and field stars. The results, using different simulated data sets (N = 1, 2 and 4 variables), show that the method properly recovers a very high fraction of simulated cluster members, with a low number of misclassified stars. To compare the goodness of our methodology, we also run other existing algorithms on the same simulated data. The results show that our method has a similar or even better performance than the other techniques. We study the robustness of the new methodology from different subsamplings of the initial sample, showing a progressive deterioration of the capability of our method as the fraction of missing objects increases. Finally, we apply all the methodologies to the real cluster NGC 2682, indicating that our methodology is again in good agreement with preceding studies.

  17. A new probabilistic method for quantifying n-dimensional ecological niches and niche overlap.

    PubMed

    Swanson, Heidi K; Lysy, Martin; Power, Michael; Stasko, Ashley D; Johnson, Jim D; Reist, James D

    2015-02-01

    Considerable progress has been made in the development of statistical tools to quantify trophic relationships using stable isotope ratios, including tools that address size and overlap of isotopic niches. We build upon recent progress and propose a new probabilistic method for determining niche region and pairwise niche overlap that can be extended beyond two dimensions, provides directional estimates of niche overlap, accounts for species-specific distributions in niche space, and, unlike geometric methods, produces consistent and unique bivariate projections of multivariate data. We define the niche region (NR) as a given 95% (or user-defined a) probability region in multivariate space. Overlap is calculated as the probability that an individual from species A is found in the N(R) of species B. Uncertainty is accounted for in a Bayesian framework, and is the only aspect of the methodology that depends on sample size. Application is illustrated with three-dimensional stable isotope data, but practitioners could use any continuous indicator of ecological niche in any number of dimensions. We suggest that this represents an advance in our ability to quantify and compare ecological niches in a way that is more consistent with Hutchinson's concept of an "n-dimensional hypervolume". PMID:26240852

  18. N-dimensional B-spline surface estimated by lofting for locally improving IRI

    NASA Astrophysics Data System (ADS)

    Koch, K.; Schmidt, M.

    2011-03-01

    N-dimensional surfaces are defined by the tensor product of B-spline basis functions. To estimate the unknown control points of these B-spline surfaces, the lofting method also called skinning method by cross-sectional curve fits is applied. It is shown by an analytical proof and numerically confirmed by the example of a four-dimensional surface that the results of the lofting method agree with the ones of the simultaneous estimation of the unknown control points. The numerical complexity for estimating vn control points by the lofting method is O(vn+1) while it results in O(v3n) for the simultaneous estimation. It is also shown that a B-spline surface estimated by a simultaneous estimation can be extended to higher dimensions by the lofting method, thus saving computer time. An application of this method is the local improvement of the International Reference Ionosphere (IRI), e.g. by the slant total electron content (STEC) obtained by dual-frequency observations of the Global Navigation Satellite System (GNSS). Three-dimensional B-spline surfaces at different time epochs have to be determined by the simultaneous estimation of the control points for this improvement. A four-dimensional representation in space and time of the electron density of the ionosphere is desirable. It can be obtained by the lofting method. This takes less computer time than determining the four-dimensional surface solely by a simultaneous estimation.

  19. 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.

  20. GENERATING ON-THE-FLY LARGE SAMPLES OF THEORETICAL SPECTRA THROUGH AN N-DIMENSIONAL GRID

    SciTech Connect

    Yip, C.-W.

    2010-02-15

    Many analyses and parameter estimations undertaken in astronomy require a large set ({approx}>10{sup 5}) of non-analytical, theoretical spectra, each of these defined by multiple parameters. We describe the construction of an N-dimensional grid which is suitable for generating such spectra. The theoretical spectra are designed to correspond to a targeted parameter grid but otherwise to random positions in the parameter space, and they are interpolated on the fly through a pre-calculated grid of spectra. The initial grid is designed to be relatively low in parameter resolution and small in occupied hard disk space and therefore can be updated efficiently when a new model is desired. In a pilot study of stellar population synthesis of galaxies, the mean square errors on the estimated parameters are found to decrease with the targeted grid resolution. This scheme of generating a large model grid is general for other areas of studies, particularly if they are based on multi-dimensional parameter space and are focused on contrasting model differences.

  1. 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

  2. Family of N-dimensional superintegrable systems and quadratic algebra structures

    NASA Astrophysics Data System (ADS)

    Fazlul Hoque, Md; Marquette, Ian; Zhang, Yao-Zhong

    2016-01-01

    Classical and quantum superintegrable systems have a long history and they possess more integrals of motion than degrees of freedom. They have many attractive properties, wide applications in modern physics and connection to many domains in pure and applied mathematics. We overview two new families of superintegrable Kepler-Coulomb systems with non-central terms and superintegrable Hamiltonians with double singular oscillators of type (n, N — n) in N-dimensional Euclidean space. We present their quadratic and polynomial algebras involving Casimir operators of so(N + 1) Lie algebras that exhibit very interesting decompositions Q(3) ⊕ so(N — 1), Q(3) ⊕ so(n) ⊕ so(N — n) and the cubic Casimir operators. The realization of these algebras in terms of deformed oscillator enables the determination of a finite dimensional unitary representation. We present algebraic derivations of the degenerate energy spectra of these systems and relate them with the physical spectra obtained from the separation of variables.

  3. 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.

  4. 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.

  5. 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, we 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. We 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.

  6. 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.

  7. Classical and quantum equations of motion of an n-dimensional BTZ black hole

    NASA Astrophysics Data System (ADS)

    Greenwood, Eric

    2016-05-01

    We investigate the gravitational collapse of a non-rotating n-dimensional BTZ black hole in AdS space in the context of both classical and quantum mechanics. This is done by first deriving the conserved mass of a "spherically" symmetric domain wall, which is taken as the classical Hamiltonian of the black hole. Upon deriving the conserved mass, we also point out that, for a "spherically" symmetric shell, there is an easy and straight-forward way of determining the conserved mass, which is related to the proper time derivative of the interior and exterior times. This method for determining the conserved mass is generic to any situation (i.e. any equation of state), since it only depends on the energy per unit area, σ, of the shell. Classically, we show that the time taken for gravitational collapse follows that of the typical formation of a black hole via gravitational collapse; that is, an asymptotic observer will see that the collapse takes an infinite amount of time to occur, while an infalling observer will see the collapse to both the horizon and the classical singularity occur in a finite amount of time. Quantum mechanically, we take primary interest in the behavior of the collapse near the horizon and near the classical singularity from the point of view of both asymptotic and infalling observers. In the absence of radiation and fluctuations of the metric, quantum effects near the horizon do not change the classical conclusions for an asymptotic observer. The most interesting quantum mechanical effect comes in when investigating near the classical singularity. Here, we find, that the quantum effects in this region are able to remove the classical singularity at the origin, since the wave function is non-singular, and it also displays non-local effects, which depend on the energy density of the domain wall.

  8. An N-Dimensional Pseudo-Hilbert Scan for Arbitrarily-Sized Hypercuboids

    NASA Astrophysics Data System (ADS)

    Zhang, Jian; Kamata, Sei-Ichiro

    The N-dimensional (N-D) Hilbert curve is a one-to-one mapping between N-D space and one-dimensional (1-D) space. It is studied actively in the area of digital image processing as a scan technique (Hilbert scan) because of its property of preserving the spatial relationship of the N-D patterns. Currently there exist several Hilbert scan algorithms. However, these algorithms have two strict restrictions in implementation. First, recursive functions are used to generate a Hilbert curve, which makes the algorithms complex and computationally expensive. Second, all the sides of the scanned region must have the same size and the length must be a power of two, which limits the application of the Hilbert scan greatly. Thus in order to remove these constraints and improve the Hilbert scan for general application, a nonrecursive N-D Pseudo-Hilbert scan algorithm based on two look-up tables is proposed in this paper. The merit of the proposed algorithm is that implementation is much easier than the original one while preserving the original characteristics. The experimental results indicate that the Pseudo-Hilbert scan can preserve point neighborhoods as much as possible and take advantage of the high correlation between neigh-boring lattice points, and it also shows the competitive performance of the Pseudo-Hilbert scan in comparison with other common scan techniques. We believe that this novel scan technique undoubtedly leads to many new applications in those areas can benefit from reducing the dimensionality of the problem.

  9. Intrinsically disordered proteins and biomineralization.

    PubMed

    Boskey, Adele L; Villarreal-Ramirez, Eduardo

    2016-01-01

    In vertebrates and invertebrates, biomineralization is controlled by the cell and the proteins they produce. A large number of these proteins are intrinsically disordered, gaining some secondary structure when they interact with their binding partners. These partners include the component ions of the mineral being deposited, the crystals themselves, the template on which the initial crystals form, and other intrinsically disordered proteins and peptides. This review speculates why intrinsically disordered proteins are so important for biomineralization, providing illustrations from the SIBLING (small integrin binding N-glycosylated) proteins and their peptides. It is concluded that the flexible structure, and the ability of the intrinsically disordered proteins to bind to a multitude of surfaces is crucial, but details on the precise-interactions, energetics and kinetics of binding remain to be determined. PMID:26807759

  10. Intrinsic magnetization of antiferromagnetic textures

    NASA Astrophysics Data System (ADS)

    Tveten, Erlend G.; Müller, Tristan; Linder, Jacob; Brataas, Arne

    2016-03-01

    Antiferromagnets (AFMs) exhibit intrinsic magnetization when the order parameter spatially varies. This intrinsic spin is present even at equilibrium and can be interpreted as a twisting of the homogeneous AFM into a state with a finite spin. Because magnetic moments couple directly to external magnetic fields, the intrinsic magnetization can alter the dynamics of antiferromagnetic textures under such influence. Starting from the discrete Heisenberg model, we derive the continuum limit of the free energy of AFMs in the exchange approximation and explicitly rederive that the spatial variation of the antiferromagnetic order parameter is associated with an intrinsic magnetization density. We calculate the magnetization profile of a domain wall and discuss how the intrinsic magnetization reacts to external forces. We show conclusively, both analytically and numerically, that a spatially inhomogeneous magnetic field can move and control the position of domain walls in AFMs. By comparing our model to a commonly used alternative parametrization procedure for the continuum fields, we show that the physical interpretations of these fields depend critically on the choice of parametrization procedure for the discrete-to-continuous transition. This can explain why a significant amount of recent studies of the dynamics of AFMs, including effective models that describe the motion of antiferromagnetic domain walls, have neglected the intrinsic spin of the textured order parameter.

  11. The Impact of Curiosity and External Regulation on Intrinsic Motivation: An Empirical Study in Hong Kong Education

    ERIC Educational Resources Information Center

    Hon-keung, Yau; Man-shan, Kan; Lai-fong, Cheng Alison

    2012-01-01

    The purposes of this paper are to identify: (1) the factors affecting the intrinsic motivation of university students in Hong Kong; and (2) gender differences in the perception of intrinsic motivation in Hong Kong higher education environment. The factors of curiosity and external regulation with intrinsic motivation are taken into investigation…

  12. 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 ...

  13. 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…

  14. Intrinsic disorder in transcription factors†

    PubMed Central

    Liu, Jiangang; Perumal, Narayanan B.; Oldfield, Christopher J.; Su, Eric W.; Uversky, Vladimir N.; Dunker, A. Keith

    2008-01-01

    Intrinsic disorder (ID) is highly abundant in eukaryotes, which reflect the greater need for disorder-associated signaling and transcriptional regulation in nucleated cells. Although several well-characterized examples of intrinsically disordered proteins in transcriptional regulation have been reported, no systematic analysis has been reported so far. To test for a general prevalence of intrinsic disorder in transcriptional regulation, we used the Predictor Of Natural Disorder Regions (PONDR) to analyze the abundance of intrinsic disorder in three transcription factor datasets and two control sets. This analysis revealed that from 94.13% to 82.63% of transcription factors posses extended regions of intrinsic disorder, relative to 54.51% and 18.64% of the proteins in two control datasets, which indicates the significant prevalence of intrinsic disorder in transcription factors. This propensity of transcription factors for intrinsic disorder was confirmed by cumulative distribution function analysis and charge-hydropathy plots. The amino acid composition analysis showed that all three transcription factor datasets were substantially depleted in order-promoting residues, and significantly enriched in disorder-promoting residues. Our analysis of the distribution of disorder within the transcription factor datasets revealed that: (a) The AT-hooks and basic regions of transcription factor DNA-binding domains are highly disordered; (b) The degree of disorder in transcription factor activation regions is much higher than that in DNA-binding domains; (c) The degree of disorder is significantly higher in eukaryotic transcription factors than in prokaryotic transcription factors; (d) The level of α-MoRFs (molecular recognition feature) prediction is much higher in transcription factors. Overall, our data reflected the fact that the eukaryotes with well-developed gene transcription machinery require transcription factor flexibility to be more efficient. PMID:16734424

  15. Phylogeny of major intrinsic proteins.

    PubMed

    Danielson, Jonas A H; Johanson, Urban

    2010-01-01

    Major intrinsic proteins (MIPs) form a large superfamily of proteins that can be divided into different subfamilies and groups according to phylogenetic analyses. Plants encode more MIPs than o ther organisms and se ven subfamilies have been defined, whereofthe Nodulin26-like major intrinsic proteins (NIPs) have been shown to permeate metalloids. In this chapter we review the phylogeny of MIPs in general and especially of the plant MIPs. We also identify bacterial NIP-like MIPs and discuss the evolutionary implications of this finding regarding the origin and ancestral transport specificity of the NIPs. PMID:20666221

  16. Intrinsic and Extrinsic Motivation for Smoking Cessation.

    ERIC Educational Resources Information Center

    Curry, Susan; And Others

    1990-01-01

    Evaluated intrinsic-extrinsic model of motivation for smoking cessation using two samples (Ns=1,217 and 151) of smokers. Analysis on Reasons for Quitting scale supported intrinsic-extrinsic motivation distinction, defining four-factor model with two intrinsic and two extrinsic dimensions. Found that smokers with higher levels of intrinsic relative…

  17. Reading: Intrinsic versus Extrinsic Motivation.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Much debate centers on motivating student in reading achievement. Should students feel motivated from within (intrinsic motivation), or is it better to have extrinsic motivation whereby external stimuli are used to help learners achieve optimally in reading? This paper aims to analyze the two points of view about motivating students in reading…

  18. Individual Patterns in Intrinsic Motivation.

    ERIC Educational Resources Information Center

    Hom, Harry L., Jr.; Maxwell, Frederick R.

    The effects of extrinsic reward on students' intrinsic interest was investigated using a single-subject design in a behavior disorders classroom. Baseline measures of the interest level of five children (ages 9-11 years) were collected for academic and non-academic tasks. Assessment was then made of each subject's response hierarchy or level of…

  19. Thermodynamic geometry and thermal stability of n -dimensional dilaton black holes in the presence of logarithmic nonlinear electrodynamics

    NASA Astrophysics Data System (ADS)

    Sheykhi, A.; Naeimipour, F.; Zebarjad, S. M.

    2015-12-01

    In this paper, we construct a new class of black hole solutions which is coupled to the logarithmic nonlinear electrodynamics in the context of dilaton gravity. We consider an n -dimensional action in which gravity is coupled to the logarithmic nonlinear electrodynamics field and a scalar dilaton field to obtain the equations of motion of the gravitational, dilaton and electromagnetic fields. This leads to finding a new class of n -dimensional static and spherically symmetric black hole solutions in the presence of two Liouville-type dilaton potentials. The asymptotic behavior of these solutions is neither flat nor (anti-)de Sitter [(A)dS], and in the limiting case where the nonlinear parameter β goes to infinity, our solutions reduce to the black holes of Einstein-Maxwell-dilaton gravity in higher dimensions. Thermodynamic quantities such as mass, temperature, electric potential and entropy are also computed, and it is shown that they agree with the first law of thermodynamics. Furthermore, we find that for small values of the electric charge parameter q , and the dilaton coupling constant α , as well as small dimension n , the solutions are thermally stable. By increasing n , the region of stability stands for smaller values of α independent of q . Finally, we use the method of thermodynamical geometry and find the phase transition points by calculating the Ricci scalar of a thermodynamic metric.

  20. [Intrinsically Photosensitive Retinal Ganglion Cells].

    PubMed

    Skorkovská, K; Skorkovská, Š

    2015-06-01

    Recently discovered intrinsically photosensitive melanopsin-containing retinal ganglion cells contribute to circadian photoentrainment and pupillary constriction; recent works have also brought new evidence for their accessory role in the visual system in humans. Pupil light reaction driven by individual photoreceptors can be isolated by means of the so called chromatic pupillography. The use of chromatic stimuli to elicit different pupillary responses may become an objective clinical pupil test in the detection of retinal diseases and in assessing new therapeutic approaches particularly in hereditary retinal degenerations like retinitis pigmentosa. In advanced stages of disease, the pupil light reaction is even more sensitive than standard electroretinography for detecting residual levels of photoreceptor activity. This review summarizes current knowledge on intrinsically photosensitive retinal cells and highlights its possible implications for clinical practice. PMID:26201360

  1. Intrinsic Control of Axon Regeneration.

    PubMed

    He, Zhigang; Jin, Yishi

    2016-05-01

    A determinant of axon regeneration is the intrinsic growth ability of injured neurons, which dictates a battery of injury responses in axons and cell bodies. While some of these regulatory mechanisms are evolutionarily conserved, others are unique to the mammalian central nervous system (CNS) where spontaneous regeneration usually does not occur. Here we examine our current understanding of these mechanisms at cellular and molecular terms and discuss their potential implications for promoting axon regeneration and functional recovery after nerve injury. PMID:27151637

  2. 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.

  3. 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)

  4. 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

  5. Localization of intrinsic factor and complement fixing intrinsic factor–intrinsic factor antibody complex in parietal cell of man

    PubMed Central

    Jacob, Elizabeth; Glass, G. B. J.

    1971-01-01

    In an attempt to localize intrinsic factor in the human parietal cell, and to study its intracellular union with the intrinsic factor antibody and complement, intrinsic factor antibody was separated from coexisting parietal cell antibody in pernicious anaemia sera by gel filtration. Intrinsic factor antibody of both `binding' and `blocking' type was also produced in rabbits by immunization with semi-purified human intrinsic factor–[57Co]B12 complex. Intrinsic factor antibody obtained from both sources produced fluorescence in the human parietal cells in the indirect Coons' test in the presence of fluoresceinated anti-human IgG. The fluorescence was localized peripherally, at the cell membrane. When instead of the fluoresceinated anti-human IgG a fluoresceinated anti-human complement (C) serum and normal complement containing serum were used, intrinsic factor antibody from both sources produced fluorescence of the entire parietal cell cytoplasm of the human mucosa. Thus, intrinsic factor was localized at highest concentration at the membrane of the parietal cell in man, the intrinsic factor antibody–intrinsic factor complex was demonstrated within the human parietal cell, and evidence was obtained that this antigen–antibody complex fixes complement (C). The possible role of the intrinsic factor–intrinsic factor antibody–complement complex in the development of gastric atrophy in pernicious anaemia has been considered. ImagesFIG. 3FIG. 4FIG. 5 PMID:4995933

  6. Intraday Variability: Intrinsic or Extrinsic?

    NASA Astrophysics Data System (ADS)

    Sarma Kuchibhotla, Huthavahana; Lister, Matthew; Homan, Dan; Kellermann, Ken; Aller, Hugh; Aller, Margo; Agudo, Ivan; Arshakian, Tigran; Kovalev, Yuri; Lobanov, Andrew; Pushkarev, Alexander; Ros, Eduardo; Savolainen, Tuomas; Zensus, Tony; Kadler, Matthias; Vermeulen, Rene; Gehrels, Neil; McEnery, Julie; Sambruna, Rita; Tueller, Jack; Cohen, Marshall; Hovatta, Talvikki; Kharb, Preeti; Cooper, Nathan; Hogan, Brandon; Cara, Mihai

    A significant fraction of flat spectrum AGN exhibit rapid variability both in total intensity as well as polarization at cm wavelengths, on time scales ranging from a few hours to a few days, a phenomenon termed Intra Day Variability (IDV). The physical process responsible for this behavior is not well understood, though various models ranging from source-intrinsic (e.g., shock-in-jet) to source-extrinsic (e.g., scintillation due to electron density fl uctuations in the interstellar medium) have been proposed. The absence of multi-epoch data (especially at 2 cm) further exacerbates the situation. We present the results of analysis of archival VLBA data for a flux density limited sample of bright, flat spectrum AGN located predominantly in the north-ern sky, collected under the MOJAVE program. We find a clear detection of IDV in 25% of the 365 sources analyzed. We find significant differences in the IDV properties of quasars and true BL Lacs. Intermediate BL Lac objects, so classified due to the presence of broad lines in their optical spectra, have IDV characteristics similar to those of quasars. As expected, the presum-able weakly beamed CSS/GPS sources show no IDV. We find IDV properties to be correlated with source intrinsic properties such as Brightness temperature/Doppler factor and apparent speed. Episodes of IDV activity associated with radio flaring and/or component ejection have also been observed, suggesting an intrinsic mechanism at work. However, we also find IDV to be strongly correlated with the galactic latitude position of the source, indicative of a scintil-lation mechanism. However, we find no correlation between IDV and the observing day of the year, IDV and redshift of the source. We propose a qualitative model to explain all these results. The program is supported under the NSF grant 080786-AST and NASA grant NNX08AV67G.

  7. Pair breaking and ``intrinsic`` {Tc}

    SciTech Connect

    Wolf, S.A.; Kresin, V.Z.; Ovchinnikov, Y.N.

    1996-12-31

    An analysis of the temperature dependence of the upper critical field in several cuprate families leads to the conclusion that magnetic impurities are present even in samples with the maximum observed value of T{sub c}. A new parameter, intrinsic T{sub c} (T{sub c;intr}) which is its value in the absence of magnetic impurities, is introduced. The maximum value of T{sub c;intr}, which corresponds to the maximum doping level, appears to be similar for different cuprates and to be equal to 160--170 K. This is an upper limit of T{sub c} in the cuprates.

  8. 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.

  9. Intrinsic cylindrical and spherical waves

    NASA Astrophysics Data System (ADS)

    Ludlow, I. K.

    2008-02-01

    Intrinsic waveforms associated with cylindrical and spherical Bessel functions are obtained by eliminating the factors responsible for the inverse radius and inverse square radius laws of wave power per unit area of wavefront. The resulting expressions are Riccati-Bessel functions for both cases and these can be written in terms of amplitude and phase functions of order v and wave variable z. When z is real, it is shown that a spatial phase angle of the intrinsic wave can be defined and this, together with its amplitude function, is systematically investigated for a range of fixed orders and varying z. The derivatives of Riccati-Bessel functions are also examined. All the component functions exhibit different behaviour in the near field depending on the order being less than, equal to or greater than 1/2. Plots of the phase angle can be used to display the locations of the zeros of the general Riccati-Bessel functions and lead to new relations concerning the ordering of the real zeros of Bessel functions and the occurrence of multiple zeros when the argument of the Bessel function is fixed.

  10. 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

  11. 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

  12. 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…

  13. 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.

  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. 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.

  16. Superintegrability on N-dimensional spaces of constant curvature from so(N + 1) and its contractions

    SciTech Connect

    Herranz, F. J.; Ballesteros, A.

    2008-05-15

    The Lie-Poisson algebra so(N + 1) and some of its contractions are used to construct a family of superintegrable Hamiltonians on the N-dimensional spherical, Euclidean, hyperbolic, Minkowskian, and (anti-)de Sitter spaces. We firstly present a Hamiltonian which is a superposition of an arbitrary central potential with N arbitrary centrifugal terms. Such a system is quasi-maximally superintegrable since this is endowed with 2N - 3 functionally independent constants of motion (plus the Hamiltonian). Secondly, we identify two maximally superintegrable Hamiltonians by choosing a specific central potential and finding at the same time the remaining integral. The former is the generalization of the Smorodinsky-Winternitz system to the above six spaces, while the latter is a generalization of the Kepler-Coulomb potential, for which the Laplace-Runge-Lenz N vector is also given. All the systems and constants of motion are explicitly expressed in a unified form in terms of ambient and polar coordinates as they are parametrized by two contraction parameters (curvature and signature of the metric).

  17. Intrinsic ductility of glassy solids

    NASA Astrophysics Data System (ADS)

    Shi, Yunfeng; Luo, Jian; Yuan, Fenglin; Huang, Liping

    2014-01-01

    Glasses are usually brittle, seriously limiting their practical usage. Recently, the intrinsic ductility of glass was found to increase with the Poisson's ratio (v), with a sharp brittle-to-ductile (BTD) transition at vBTD = 0.31-0.32. Such a correlation between far-from-equilibrium fracture and near-equilibrium elasticity is unexpected and not understood. Molecular dynamics simulations, on three families of glasses (metallic glasses, amorphous silicon, and silica) with controlled bonding, processing, and testing conditions, show that glasses with low covalency and high structural disorder have high v and ductility, and vice versa. The BTD transitions triggered by the aforementioned causes in each system correspond to a unified vBTD value, which increases with its average coordination number (CN). The vBTD-CN relation can be comprehended by recognizing v as a measure of covalency and disorder, and the BTD transition as a competition between shear and cleavage. Our results provide guidelines for developing new recipes and processes for tough glasses.

  18. 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

  19. Intelligent Viscoelastic Polyurethane Intrinsic Nanocomposites

    NASA Astrophysics Data System (ADS)

    Bilal Khan, M.

    2010-04-01

    Polyurethanes are multiphase systems comprising intrinsically variant nanodomains. The material properties can be tailored by adjusting the relative proportions and organizing the structure of the hard and soft segments akin to the spring-dashpot system in an automobile. This article describes how an intelligent polyurethane (PU) system is created to offer smart response to mechanical and vibration stimuli. In this work, unidirectional, dynamic mechanical thermal analysis (DMTA), acoustic, and impact testing results are qualified with the unique viscoelastic character that determines the rate-temperature response of the nanocomposite. Attenuated total reflection- infrared spectroscopy (ATR-IR) and DMTA offer a logical explanation of the observed viscoelastic behavior in terms of the nanodomains. Enhanced nanophase segregation between the polymer building blocks (hard and soft segments) is the primary mechanism that leads to a higher loss tangent peak in DMTA at a lower glass transition temperature ( T g ) for greater energy dissipation in the polymer matrix. Acoustic and impact attenuation are correlated with the mechanical modulus and loss tangent of the polymer. Finally, autodyne simulation reveals the unique shock absorbent behavior of the material layer when retrofitted to concrete structure. Typically, shock overpressure spikes of the order of 9.97 × 104 MPa experienced by the unprotected surface are entirely evened out at a lower overpressure threshold.

  20. Intrinsic Localized Modes in Proteins.

    PubMed

    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

  1. 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

  2. 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).

  3. 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.

  4. 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

  5. Intrinsic operators for the electromagnetic nuclear current

    SciTech Connect

    J. Adam, Jr.; H. Arenhovel

    1996-09-01

    The intrinsic electromagnetic nuclear meson exchange charge and current operators arising from a separation of the center-of-mass motion are derived for a one-boson-exchange model for the nuclear interaction with scalar, pseudoscalar and vector meson exchange including leading order relativistic terms. Explicit expressions for the meson exchange operators corresponding to the different meson types are given in detail for a two-nucleon system. These intrinsic operators are to be evaluated between intrinsic wave functions in their center-of-mass frame.

  6. Pseudoclassical Foldy-Wouthuysen transformation and canonical quantization of ( D=2 n)-dimensional relativistic particle with spin in an external electromagnetic field

    NASA Astrophysics Data System (ADS)

    Grigoryan, G. V.; Grigoryan, R. P.

    1995-03-01

    The canonical quantization of a ( D=2n)-dimensional Dirac particle with spin in an arbitrary external electromagnetic field is performed in a gauge that makes it possible to describe simultaneously particles and antiparticles (both massive and massiess) already at the classical level. A pseudoclassical Foldy-Wouthuysen transformation is used to find the canonical (Newton-Wigner) coordinates. The connection between this quantization scheme and Blount's picture describing the behavior of a Dirac particle in an external electromagnetic field is discussed.

  7. 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

  8. 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

  9. 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.

  10. Intrinsic and acquired resistance mechanisms in enterococcus

    PubMed Central

    Hollenbeck, Brian L.; Rice, Louis B.

    2012-01-01

    Enterococci have the potential for resistance to virtually all clinically useful antibiotics. Their emergence as important nosocomial pathogens has coincided with increased expression of antimicrobial resistance by members of the genus. The mechanisms underlying antibiotic resistance in enterococci may be intrinsic to the species or acquired through mutation of intrinsic genes or horizontal exchange of genetic material encoding resistance determinants. This paper reviews the antibiotic resistance mechanisms in Enterococcus faecium and Enterococcus faecalis and discusses treatment options. PMID:23076243

  11. 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

  12. 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…

  13. 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…

  14. 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…

  15. Reactions of human and hog intrinsic factors with type I antibody to intrinsic factor

    PubMed Central

    Gullberg, R.

    1970-01-01

    A simple and rapid small-scale gel filtration method was applied in studies of type I antibody to intrinsic factor using radioactive vitamin B12 of high specific activity and purified human and hog intrinsic factor preparations, taking into account the unsaturated B12-binding capacity of the individual pernicious anaemia sera. This procedure allows the use of small amounts of reagents. Evidence was obtained for a close antigenic similarity of determinants of human and hog intrinsic factor. The use of purified intrinsic-factor preparations is important. PMID:4097742

  16. 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.

  17. 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…

  18. Case for an open universe

    NASA Technical Reports Server (NTRS)

    Canuto, V.; Hsieh, S.-H.

    1980-01-01

    The determination of the geometrical structure of the universe through the magnitude-vs-redshift relation in standard cosmology has not been very successful, mainly because of the intrinsic insensitivity of the m-vs-z relation to a deceleration parameter, which determines the spatial curvature and therefore the geometry. By relaxing the assumption usually made, i.e., the identity of gravitational and atomic clocks, sufficient sensitivity is achieved. Existing observational evidence then leads one to conclude that the universe is open.

  19. Intrinsic and extrinsic switching in molecular devices

    NASA Astrophysics Data System (ADS)

    van der Molen, Sense Jan; Trouwborst, Marius L.

    2015-01-01

    The details of metal-molecule coupling play a pivotal role in the functionality of molecular junctions. Molecules that have intrinsic switchable properties may lose this capability after coupling to electrodes. On the other hand, connecting passive molecules to electrodes may lead to a switchable molecular device ('extrinsic switching'). Here, we first discuss this general matter, and then focus on two specific cases, one of intrinsic switching (for photochromic diarylethenes) and one of extrinsic switching (for hydrogen molecules) in gold-molecule-gold structures.

  20. 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.

  1. 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.

  2. Pseudoclassical Foldy-Wouthuysen transformation and canonical quantization of (D-2n)-dimensional relativistic particle with spin in an external electromagnetic field

    SciTech Connect

    Grigoryan, G.V.; Grigoryan, R.P.

    1995-09-01

    The canonical quantization of a (D=2n)-dimensional Dirac particle with spin in an arbitrary external electromagnetic field is performed in a gauge that makes it possible to describe simultaneously particles and antiparticles (both massive and massless) already at the classical level. A pseudoclassical Foldy-Wouthuysen transformation is used to find the canonical (Newton-Wigner) coordinates. The connection between this quantization scheme and Blount`s picture describing the behavior of a Dirac particle in an external electromagnetic field is discussed.

  3. Exact period-four solutions of a family of n-dimensional quadratic maps via harmonic balance and Gröbner bases.

    PubMed

    D'Amico, María Belén; Calandrini, Guillermo L

    2015-11-01

    Analytical solutions of the period-four orbits exhibited by a classical family of n-dimensional quadratic maps are presented. Exact expressions are obtained by applying harmonic balance and Gröbner bases to a single-input single-output representation of the system. A detailed study of a generalized scalar quadratic map and a well-known delayed logistic model is included for illustration. In the former example, conditions for the existence of bistability phenomenon are also introduced. PMID:26627573

  4. 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.

  5. 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…

  6. 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

  7. Revitalizing Faculty Work through Intrinsic Rewards.

    ERIC Educational Resources Information Center

    Froh, Robert C.; And Others

    1993-01-01

    A faculty survey suggests that college climate can help maximize faculty effectiveness. Institutions are making use of the intrinsic rewards of academic work to improve its quality, by helping faculty reach new levels of understanding and mutual learning with students, accomplish greater mastery of content, and find successful new teaching…

  8. 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…

  9. Intrinsic Factors Affecting Overseas Student Teaching

    ERIC Educational Resources Information Center

    Firmin, Michael W.; MacKay, Brenda B.; Firmin, Ruth L.

    2007-01-01

    We conducted a qualitative research study involving 13 undergraduate students who completed their student-teaching in overseas contexts. Participants completed two waves of interviews immediately after returning to campus from their multicultural experiences. Three intrinsic factors were found to have the greatest impact on students' overseas…

  10. 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

  11. 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…

  12. The intrinsic cost of cognitive control.

    PubMed

    Kool, Wouter; Botvinick, Matthew

    2013-12-01

    Kurzban and colleagues carry forward an important contemporary movement in cognitive control research, tending away from resource-based models and toward a framework focusing on motivation or value. However, their specific proposal, centering on opportunity costs, appears problematic. We favor a simpler view, according to which the exertion of cognitive control carries intrinsic subjective costs. PMID:24304795

  13. 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

  14. Visual stimuli recruit intrinsically generated cortical ensembles

    PubMed Central

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

    2014-01-01

    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

  15. 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.

  16. 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.

  17. Advancing polymers of intrinsic microporosity by mechanochemistry

    DOE PAGESBeta

    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.

  18. Archaic chaos: intrinsically disordered proteins in Archaea

    PubMed Central

    2010-01-01

    Background Many proteins or their regions known as intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) lack unique 3D structure in their native states under physiological conditions yet fulfill key biological functions. Earlier bioinformatics studies showed that IDPs and IDRs are highly abundant in different proteomes and carry out mostly regulatory functions related to molecular recognition and signal transduction. Archaea belong to an intriguing domain of life whose members, being microbes, are characterized by a unique mosaic-like combination of bacterial and eukaryotic properties and include inhabitants of some of the most extreme environments on the planet. With the expansion of the archaea genome data (more than fifty archaea species from five different phyla are known now), and with recent improvements in the accuracy of intrinsic disorder prediction, it is time to re-examine the abundance of IDPs and IDRs in the archaea domain. Results The abundance of IDPs and IDRs in 53 archaea species is analyzed. The amino acid composition profiles of these species are generally quite different from each other. The disordered content is highly species-dependent. Thermoproteales proteomes have 14% of disordered residues, while in Halobacteria, this value increases to 34%. In proteomes of these two phyla, proteins containing long disordered regions account for 12% and 46%, whereas 4% and 26% their proteins are wholly disordered. These three measures of disorder content are linearly correlated with each other at the genome level. There is a weak correlation between the environmental factors (such as salinity, pH and temperature of the habitats) and the abundance of intrinsic disorder in Archaea, with various environmental factors possessing different disorder-promoting strengths. Harsh environmental conditions, especially those combining several hostile factors, clearly favor increased disorder content. Intrinsic disorder is highly abundant

  19. [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). PMID:14560551

  20. Intrinsic motivation towards sports in Singaporean students: the role of sport ability beliefs.

    PubMed

    Wang, C K John; Biddle, Stuart J H

    2003-09-01

    This study investigated determinants of active lifestyles in Singaporean university students. Using confirmatory factor analysis, a measure of lay beliefs concerning athletic ability was confirmed. Other results confirmed hypotheses that beliefs reflecting that athletic ability can be developed over time (incremental beliefs) predict an achievement task (self-referenced) orientation, while beliefs reflecting that athletic ability is relatively stable (entity beliefs) predict an ego (other-person, comparative) orientation. Goal orientations directly affect perceived competence which, in turn, influence intrinsic motivation to be physically active. A task orientation had a direct link to intrinsic motivation. Results suggest that intrinsic motivation towards sport and physical activity might be enhanced through interventions that focus on self-referenced and self-improvement notions of ability as well as perceived competence. PMID:19177714

  1. 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.

  2. 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.

  3. 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.

  4. Intrinsically disordered proteins from A to Z.

    PubMed

    Uversky, Vladimir N

    2011-08-01

    The ideas that proteins might possess specific functions without being uniquely folded into rigid 3D-structures and that these floppy polypeptides might constitute a noticeable part of any given proteome would have been considered as a preposterous fiction 15 or even 10 years ago. The situation has changed recently, and the existence of functional yet intrinsically disordered proteins and regions has become accepted by a significant number of protein scientists. These fuzzy objects with fuzzy structures and fuzzy functions are among the most interesting and attractive targets for modern protein research. This review summarizes some of the major discoveries and breakthroughs in the field of intrinsic disorder by representing related concepts and definitions. PMID:21501695

  5. 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.

  6. Intrinsic two-dimensional features as textons.

    PubMed

    Barth, E; Zetzsche, C; Rentschler, I

    1998-07-01

    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. PMID:9656473

  7. 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.

  8. Design Space Issues for Intrinsic Evolvable Hardware

    NASA Technical Reports Server (NTRS)

    Hereford, James; Gwaltney, David

    2004-01-01

    This paper discusses the problem of increased programming time for intrinsic evolvable hardware (EM) as the complexity of the circuit grows. As the circuit becomes more complex, then more components will be required and a longer programming string, L, is required. We develop equations for the size of the population, n, and the number of generations required for the population to converge, based on L. Our analytical results show that even though the design search space grows as 2L (assuming a binary programming string), the number of circuit evaluations, n*ngen, only grows as O(Lg3), or slightly less than O(L). This makes evolvable techniques a good tool for exploring large design spaces. The major hurdle for intrinsic EHW is evaluation time for each possible circuit. The evaluation time involves downloading the bit string to the device, updating the device configuration, measuring the output and then transferring the output data to the control processor. Each of these steps must be done for each member of the population. The processing time of the computer becomes negligible since the selection/crossover/mutation steps are only done once per generation. Evaluation time presently limits intrinsic evolvable hardware techniques to designing only small or medium-sized circuits. To evolve large or complicated circuits, several researchers have proposed using hierarchical design or reuse techniques where submodules are combined together to form complex circuits. However, these practical approaches limit the search space of available designs and preclude utilizing parasitic coupling or other effects within the programmable device. The practical approaches also raise the issue of why intrinsic EHW techniques do not easily apply to large design spaces, since the analytical results show only an O(L) complexity growth.

  9. Transversity and intrinsic motion of the constituents

    SciTech Connect

    Efremov, A.V.; Teryaev, O.V.; Zavada, P.

    2004-09-01

    The probabilistic model of parton distributions, previously developed by one of the authors, is generalized to include the transversity distribution. When interference effects are attributed to quark level only, the intrinsic quark motion produces the transversity, which is about twice as large as the usual polarized distribution. The applicability of such a picture is considered and possible corrections, accounting for interference effects at the parton-hadron transition stage are discussed.

  10. 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. PMID:8804885

  11. 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

  12. Intrinsic and extrinsic effects on image memorability.

    PubMed

    Bylinskii, Zoya; Isola, Phillip; Bainbridge, Constance; Torralba, Antonio; Oliva, Aude

    2015-11-01

    Previous studies have identified that images carry the attribute of memorability, a predictive value of whether a novel image will be later remembered or forgotten. Here we investigate the interplay between intrinsic and extrinsic factors that affect image memorability. First, we find that intrinsic differences in memorability exist at a finer-grained scale than previously documented. Second, we test two extrinsic factors: image context and observer behavior. Building on prior findings that images that are distinct with respect to their context are better remembered, we propose an information-theoretic model of image distinctiveness. Our model can automatically predict how changes in context change the memorability of natural images. In addition to context, we study a second extrinsic factor: where an observer looks while memorizing an image. It turns out that eye movements provide additional information that can predict whether or not an image will be remembered, on a trial-by-trial basis. Together, by considering both intrinsic and extrinsic effects on memorability, we arrive at a more complete and fine-grained model of image memorability than previously available. PMID:25796976

  13. Kinesin tail domains are intrinsically disordered.

    PubMed

    Seeger, Mark A; Zhang, Yongbo; Rice, Sarah E

    2012-10-01

    Kinesin motor proteins transport a wide variety of molecular cargoes in a spatially and temporally regulated manner. Kinesin motor domains, which hydrolyze ATP to produce a directed mechanical force along a microtubule, are well conserved throughout the entire superfamily. Outside of the motor domains, kinesin sequences diverge along with their transport functions. The nonmotor regions, particularly the tails, respond to a wide variety of structural and molecular cues that enable kinesins to carry specific cargoes in response to particular cellular signals. Here, we demonstrate that intrinsic disorder is a common structural feature of kinesins. A bioinformatics survey of the full-length sequences of all 43 human kinesins predicts that significant regions of intrinsically disordered residues are present in all kinesins. These regions are concentrated in the nonmotor domains, particularly in the tails and near sites for ligand binding or post-translational modifications. In order to experimentally verify these predictions, we expressed and purified the tail domains of kinesins representing three different families (Kif5B, Kif10, and KifC3). Circular dichroism and NMR spectroscopy experiments demonstrate that the isolated tails are disordered in vitro, yet they retain their functional microtubule-binding activity. On the basis of these results, we propose that intrinsic disorder is a common structural feature that confers functional specificity to kinesins. PMID:22674872

  14. Kinesin Tail Domains Are Intrinsically Disordered

    PubMed Central

    Seeger, Mark A.; Zhang, Yongbo; Rice, Sarah E.

    2012-01-01

    Kinesin motor proteins transport a wide variety of molecular cargoes in a spatially and temporally regulated manner. Kinesin motor domains, which hydrolyze ATP to produce a directed mechanical force along a microtubule, are well conserved throughout the entire superfamily. Outside of the motor domains, kinesin sequences diverge along with their transport functions. The non-motor regions, particularly the tails, respond to a wide variety of structural and molecular cues that enable kinesins to carry specific cargoes in response to particular cellular signals. Here, we demonstrate that intrinsic disorder is a common structural feature of kinesins. A bioinformatics survey of the full-length sequences of all 43 human kinesins predicts that significant regions of intrinsically disordered residues are present in all kinesins. These regions are concentrated in the non-motor domains, particularly in the tails and near sites for ligand binding or post-translational modifications. In order to experimentally verify these predictions, we expressed and purified the tail domains of kinesins representing three different families (Kif5B, Kif10, and KifC3). Circular dichroism (CD) and NMR spectroscopy experiments demonstrate that the isolated tails are disordered in vitro, yet they retain their functional microtubule-binding activity. Based on these results, we propose that intrinsic disorder is a common structural feature that confers functional specificity to kinesins. PMID:22674872

  15. Intrinsic disorder accelerates dissociation rather than association.

    PubMed

    Umezawa, Koji; Ohnuki, Jun; Higo, Junichi; Takano, Mitsunori

    2016-08-01

    The intrinsically disordered protein (IDP) has distinct properties both physically and biologically: it often becomes folded when binding to the target and is frequently involved in signal transduction. The physical property seems to be compatible with the biological property where fast association and dissociation between IDP and the target are required. While fast association has been well studied, fueled by the fly-casting mechanism, the dissociation kinetics has received less attention. We here study how the intrinsic disorder affects the dissociation kinetics, as well as the association kinetics, paying attention to the interaction strength at the binding site (i.e., the quality of the "fly lure"). Coarse-grained molecular dynamics simulation of the pKID-KIX system, a well-studied IDP system, shows that the association rate becomes larger as the disorder-inducing flexibility that was imparted to the model is increased, but the acceleration is marginal and turns into deceleration as the quality of the fly lure is worsened. In contrast, the dissociation rate is greatly enhanced as the disorder is increased, indicating that intrinsic disorder serves for rapid signal switching more effectively through dissociation than association. Proteins 2016; 84:1124-1133. © 2016 Wiley Periodicals, Inc. PMID:27122223

  16. 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

  17. 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

  18. 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…

  19. Role of Intrinsic Motivation in Children's School Achievement.

    ERIC Educational Resources Information Center

    Gottfried, Adele Eskeles

    The relationship between intrinsic motivation for school learning and school achievement was investigated. An intrinsic motivation inventory was developed to test the hypotheses that intrinsic motivation is differentiated into specific subject areas for school learning; and for specific subjects is positively, significantly, and differentially…

  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... APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.34 Test for intrinsic safety. Assemblies, subassemblies, or components that are designed for intrinsic safety shall be tested...

  1. 30 CFR 18.68 - Tests for intrinsic safety.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... power for intrinsically safe circuits shall be housed in explosion-proof enclosures and be provided with... intermingled with wiring for intrinsically safe circuits. (4) Transformers that supply power for intrinsically... cover power line voltage variations. (6) In investigations of alternating current circuits a minimum...

  2. 30 CFR 18.68 - Tests for intrinsic safety.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... power for intrinsically safe circuits shall be housed in explosion-proof enclosures and be provided with... intermingled with wiring for intrinsically safe circuits. (4) Transformers that supply power for intrinsically... cover power line voltage variations. (6) In investigations of alternating current circuits a minimum...

  3. 30 CFR 18.68 - Tests for intrinsic safety.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... power for intrinsically safe circuits shall be housed in explosion-proof enclosures and be provided with... intermingled with wiring for intrinsically safe circuits. (4) Transformers that supply power for intrinsically... cover power line voltage variations. (6) In investigations of alternating current circuits a minimum...

  4. 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)

  5. Intrinsic cellular defenses against human immunodeficiency viruses.

    PubMed

    Blanco-Melo, Daniel; Venkatesh, Siddarth; Bieniasz, Paul D

    2012-09-21

    Viral infections are often detrimental to host survival and reproduction. Consequently, hosts have evolved a variety of mechanisms to defend themselves against viruses. A component of this arsenal is a set of proteins, termed restriction factors, which exhibit direct antiviral activity. Among these are several classes of proteins (APOBEC3, TRIM5, Tetherin, and SAMHD1) that inhibit the replication of human and simian immunodeficiency viruses. Here, we outline the features, mechanisms, and evolution of these defense mechanisms. We also speculate on how restriction factors arose, how they might interact with the conventional innate and adaptive immune systems, and how an understanding of these intrinsic cellular defenses might be usefully exploited. PMID:22999946

  6. Intrinsic Response Time of Graphene Photodetectors

    PubMed Central

    2011-01-01

    Graphene-based photodetectors are promising new devices for high-speed optoelectronic applications. However, despite recent efforts it is not clear what determines the ultimate speed limit of these devices. Here, we present measurements of the intrinsic response time of metal–graphene–metal photodetectors with monolayer graphene using an optical correlation technique with ultrashort laser pulses. We obtain a response time of 2.1 ps that is mainly given by the short lifetime of the photogenerated carriers. This time translates into a bandwidth of ∼262 GHz. Moreover, we investigate the dependence of the response time on gate voltage and illumination laser power. PMID:21627096

  7. Intrinsic and extrinsic mechanisms of dendritic morphogenesis.

    PubMed

    Dong, Xintong; Shen, Kang; Bülow, Hannes E

    2015-01-01

    The complex, branched morphology of dendrites is a cardinal feature of neurons and has been used as a criterion for cell type identification since the beginning of neurobiology. Regulated dendritic outgrowth and branching during development form the basis of receptive fields for neurons and are essential for the wiring of the nervous system. The cellular and molecular mechanisms of dendritic morphogenesis have been an intensely studied area. In this review, we summarize the major experimental systems that have contributed to our understandings of dendritic development as well as the intrinsic and extrinsic mechanisms that instruct the neurons to form cell type-specific dendritic arbors. PMID:25386991

  8. Paramagnetic intrinsic Meissner effect in a bulk

    NASA Astrophysics Data System (ADS)

    Lebed, A. G.

    2008-10-01

    We calculate the free energy of a quasi-two-dimensional (Q2D) superconductor with ξ⊥ < d in a parallel magnetic field, where ξ⊥ is a perpendicular to the conducting layer coherence length and d is the interlayer distance. It is shown to be different from that in the famous Lawrence-Doniach model. In particular, at high enough magnetic fields, the Meissner currents are found to create an unexpected paramagnetic moment due to the shrinking of the Cooper pairs “sizes” in a direction perpendicular to the conducting layers. We suggest measuring this paramagnetic intrinsic Meissner effect in Q2D superconductors and superconducting superlattices.

  9. 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.

  10. Intrinsic entanglement degradation by multimode detection

    SciTech Connect

    Aiello, A.; Woerdman, J.P.

    2004-08-01

    Relations between photon scattering, entanglement, and multimode detection are investigated. We first establish a general framework in which one- and two-photon elastic scattering processes can be discussed; then, we focus on the study of the intrinsic entanglement degradation caused by a multimode detection. We show that any multimode scattered state cannot maximally violate the Bell-Clauser-Horne-Shimony-Holt inequality because of the momentum spread. The results presented here have general validity and can be applied to both deterministic and random scattering processes.

  11. Intrinsically disordered proteins drive membrane curvature

    PubMed Central

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

    2015-01-01

    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. PMID:26204806

  12. 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

  13. 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

  14. Intrinsic radiation resistance in human chondrosarcoma cells

    SciTech Connect

    Moussavi-Harami, Farid; Mollano, Anthony; Martin, James A.; Ayoob, Andrew; Domann, Frederick E.; Gitelis, Steven; Buckwalter, Joseph A. . E-mail: joseph-buckwalter@uiowa.edu

    2006-07-28

    Human chondrosarcomas rarely respond to radiation treatment, limiting the options for eradication of these tumors. The basis of radiation resistance in chondrosarcomas remains obscure. In normal cells radiation induces DNA damage that leads to growth arrest or death. However, cells that lack cell cycle control mechanisms needed for these responses show intrinsic radiation resistance. In previous work, we identified immortalized human chondrosarcoma cell lines that lacked p16{sup ink4a}, one of the major tumor suppressor proteins that regulate the cell cycle. We hypothesized that the absence of p16{sup ink4a} contributes to the intrinsic radiation resistance of chondrosarcomas and that restoring p16{sup ink4a} expression would increase their radiation sensitivity. To test this we determined the effects of ectopic p16{sup ink4a} expression on chondrosarcoma cell resistance to low-dose {gamma}-irradiation (1-5 Gy). p16{sup ink4a} expression significantly increased radiation sensitivity in clonogenic assays. Apoptosis did not increase significantly with radiation and was unaffected by p16{sup ink4a} transduction of chondrosarcoma cells, indicating that mitotic catastrophe, rather than programmed cell death, was the predominant radiation effect. These results support the hypothesis that p16{sup ink4a} plays a role in the radiation resistance of chondrosarcoma cell lines and suggests that restoring p16 expression will improve the radiation sensitivity of human chondrosarcomas.

  15. 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.

  16. NdN: An intrinsic ferromagnetic semiconductor

    NASA Astrophysics Data System (ADS)

    Anton, E.-M.; McNulty, J. F.; Ruck, B. J.; Suzuki, M.; Mizumaki, M.; Antonov, V. N.; Quilty, J. W.; Strickland, N.; Trodahl, H. J.

    2016-02-01

    The rare-earth nitrides have recently regained attention due to findings that most members of the series are intrinsic ferromagnetic semiconductors, a class of materials that is crucial for the development of spintronics devices. Here we present a study of NdN thin films, with films grown via molecular beam epitaxy. Optical transmission measurements revealed a band gap of about 0.9 eV, while resistivity measurements confirmed semiconducting behavior with a negative temperature coefficient of resistance, though semimetallic behavior could not be ruled out. The room temperature resistivity of 0.6 m Ω cm indicates strong doping by nitrogen vacancies. Magnetization measurements show a ferromagnetic moment of 1.0 ±0.2 μB below the Curie temperature TC of 43 ±1 K, strongly suppressed from the Hund's rules value of 3.27 μB per ion. The ferromagnetic moment is strongly quenched and the TC is enhanced compared to previously studied bulk NdN, and crystal field calculations reveal that the quenched moment is likely due to lattice strain. X-ray magnetic circular dichroism measurements show that the magnetic moment is orbital dominant, placing NdN in the same category as SmN, an intrinsic ferromagnetic semiconductor with an orbital-dominant ferromagnetic moment.

  17. The intrinsic viscosity of linear DNA.

    PubMed

    Tsortos, Achilleas; Papadakis, George; Gizeli, Electra

    2011-12-01

    We measured the intrinsic viscosity of very small synthetic DNA molecules, of 20-395 base pairs, and incorporated them in a nearly complete picture for the whole span of molecular weights reported in the literature to date. A major transition is observed at M approximately 2 × 10(6) . It is found that in the range of approximately 7 × 10(3) ≤ M ≤ 2 × 10(6) , the intrinsic viscosity scales as [η] approximately M(1.05) , suggesting that short DNA chains are not as rigid as generally thought. The corresponding scaling for the range of 2 × 10(6) ≤ M ≤ 8 × 10(10) is [η] approximately M(0.69) . A comparison of our results with existing equations, for much narrower data distributions, is made, and the agreement is very satisfactory considering the huge range of data analyzed here. Experimental concerns such as the effect of ionic strength, polydispersity, temperature, and shear rate are discussed in detail. Some issues concerning the Huggins coefficient, polymer chain stiffness, and the relationship between the Mark-Houwink constants K, α are also presented; it is found that log K = 1.156 - 6.19α. PMID:21638275

  18. 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

  19. 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.

  20. Urinary Biomarkers Improve the Diagnosis of Intrinsic Acute Kidney Injury in Coronary Care Units

    PubMed Central

    Chang, Chih-Hsiang; Yang, Chia-Hung; Yang, Huang-Yu; Chen, Tien-Hsing; Lin, Chan-Yu; Chang, Su-Wei; Chen, Yi-Ting; Hung, Cheng-Chieh; Fang, Ji-Tseng; Yang, Chih-Wei; Chen, Yung-Chang

    2015-01-01

    Abstract Acute kidney injury (AKI) is associated with increased morbidity and mortality and is frequently encountered in coronary care units (CCUs). Its clinical presentation differs considerably from that of prerenal or intrinsic AKI. We used the biomarkers calprotectin and neutrophil gelatinase-associated lipocalin (NGAL) and compared their utility in predicting and differentiating intrinsic AKI. This was a prospective observational study conducted in a CCU of a tertiary care university hospital. Patients who exhibited any comorbidity and a kidney stressor were enrolled. Urinary samples of the enrolled patients collected between September 2012 and August 2013 were tested for calprotectin and NGAL. The definition of AKI was based on Kidney Disease Improving Global Outcomes classification. All prospective demographic, clinical, and laboratory data were evaluated as predictors of AKI. A total of 147 adult patients with a mean age of 67 years were investigated. AKI was diagnosed in 71 (50.3%) patients, whereas intrinsic AKI was diagnosed in 43 (60.5%) of them. Multivariate logistic regression analysis revealed urinary calprotectin and serum albumin as independent risk factors for intrinsic AKI. For predicting intrinsic AKI, both urinary NGAL and calprotectin displayed excellent areas under the receiver operating characteristic curve (AUROC) (0.918 and 0.946, respectively). A combination of these markers revealed an AUROC of 0.946. Our result revealed that calprotectin and NGAL had considerable discriminative powers for predicting intrinsic AKI in CCU patients. Accordingly, careful inspection for medication, choice of therapy, and early intervention in patients exhibiting increased biomarker levels might improve the outcomes of kidney injury. PMID:26448023

  1. 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,…

  2. 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. PMID:25556959

  3. Photometric Ambient Occlusion for Intrinsic Image Decomposition.

    PubMed

    Hauagge, Daniel; Wehrwein, Scott; Bala, Kavita; Snavely, Noah

    2016-04-01

    We present a method for computing ambient occlusion (AO) for a stack of images of a Lambertian scene from a fixed viewpoint. Ambient occlusion, a concept common in computer graphics, characterizes the local visibility at a point: it approximates how much light can reach that point from different directions without getting blocked by other geometry. While AO has received surprisingly little attention in vision, we show that it can be approximated using simple, per-pixel statistics over image stacks, based on a simplified image formation model. We use our derived AO measure to compute reflectance and illumination for objects without relying on additional smoothness priors, and demonstrate state-of-the art performance on the MIT Intrinsic Images benchmark. We also demonstrate our method on several synthetic and real scenes, including 3D printed objects with known ground truth geometry. PMID:26959670

  4. Paramagnetic intrinsic Meissner effect in layered superconductors

    NASA Astrophysics Data System (ADS)

    Lebed, A. G.

    2008-07-01

    Free energy of a layered superconductor with ξ⊥intrinsic Meissner effect in a bulk is suggested to detect, by measuring in-plane torque, the upper critical field and magnetization in layered organic and high- Tc superconductors, as well as in superconducting superlattices.

  5. Paramagnetic Intrinsic Meissner Effect in Layered Superconductors

    NASA Astrophysics Data System (ADS)

    Lebed, Andrei

    2008-03-01

    Free energy of a quasi-two-dimensional superconductor with a coherence length perpendicular to the conducting layers being less than an inter-layer distance is calculated. The free energy is shown to differ from that in the textbook Lawerence-Doniach model at high fields, where the Meissner currents are found to create an unexpected positive magnetic moment due to shrinking of the Cooper pairs ``sizes'' by a magnetic field. This unique phenomenon - paramagnetic intrinsic Meissner effect (PIME) in a bulk [1] - is suggested to detect by measuring in-plane magnetization and torque in layered organic and high-Tc superconductors as well as in superconducting superlattices. [1] A.G. Lebed, Physical Review Letters, submitted.

  6. Intrinsic DX Centers in Ternary Chalcopyrite Semiconductors

    SciTech Connect

    Lany, S.; Zunger, A.

    2008-01-01

    In III-V and II-VI semiconductors, certain nominally electron-donating impurities do not release electrons but instead form deep electron-traps known as 'DX centers.' While in these compounds, such traps occur only after the introduction of foreign impurity atoms, we find from first-principles calculations that in ternary I-III-VI{sub 2} chalcopyrites like CuInSe{sub 2} and CuGaSe{sub 2}, DX-like centers can develop without the presence of any extrinsic impurities. These intrinsic DX centers are suggested as a cause of the difficulties to maintain high efficiencies in CuInSe{sub 2}-based thin-film solar-cells when the band gap is increased by addition of Ga.

  7. Intrinsic glue distribution at very small x

    NASA Astrophysics Data System (ADS)

    Jalilian-Marian, Jamal; Kovner, Alex; McLerran, Larry; Weigert, Heribert

    1997-05-01

    We compute the distribution functions for gluons at very small x and not too large values of transverse momenta. We extend the McLerran-Venugopalan model by using renormalization group methods to integrate out effects due to those gluons which generate an effective classical charge density for Weizsäcker-Williams fields. We argue that this model can be extended from the description of nuclei at small x to the description of hadrons at yet smaller values of x. This generates a Lipatov-like enhancement for the intrinsic gluon distribution function and a nontrivial transverse momentum dependence as well. We estimate the transverse momentum dependence for the distribution functions, and show how the issue of unitarity is resolved in lepton-nucleus interactions.

  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 Instabilities Of Heavy Metal Fluoride Glasses

    NASA Astrophysics Data System (ADS)

    Bruce, A. J.; Moynihan, C. T.; Loehr, S. R.; Opalka, S. M.; Mossadegh, R.; Perazzo, N. L.; Bansal, N. P.; Doremus, R. H.; Doremus; Drexhage, M. G.

    1985-06-01

    Heavy metal fluoride glasses (HMFG) are potentially useful as optical components in a wide range of devices. Their utilization has so far been delayed mainly because of insufficient material purity and inadequate processing conditions. However, as the result of numerous research efforts, these problems are gradually diminishing, and it now seems likely that the ultimate limitations for use of HMFG components, at least in those applications in which high optical transparency is not a prerequisite, will be imposed by more intrinsic instabilities of the glasses themselves. These include their strong tendency to crystallize on quenching and subsequent reheating, low mechanical and chemical durability, and the possibility that they will undergo significant physical aging in situ. Experimental data relating to these problems have now been obtained, and their relative importance is assessed in this paper.

  10. 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. PMID:26440802

  11. Intrinsic topological superfluidity - fluctuations and response

    NASA Astrophysics Data System (ADS)

    Levin, K.; Wu, Chien-Te; Anderson, Brandon; Boyack, Rufus

    Recent interest in topological superconductivity is based primarily on exploiting proximity effects to obtain this important phase. However, in cold gases it is possible to contemplate ``intrinsic'' topological superfluidity produced with a synthetic spin-orbit coupling and Zeeman field. It is important for such future experiments to establish how low in temperature one needs to go to reach the ordered phase. Similarly, it will be helpful to have a probe of the normal (pseudogap) phase to determine if the ultimate superfluid order will be topological or trivial. In this talk, we address these issues by considering fluctuation effects in such a superfluid, and calculate the critical transition temperature and response functions. We see qualitative signatures of topological superfluidity in spin and charge response functions. We also explore the suppression of superfluidity due to fluctuations, and importantly find that the temperature scales necessary to reach topological superfluidity are reasonably accessible

  12. Intrinsic superstatistical components of financial time series

    NASA Astrophysics Data System (ADS)

    Vamoş, Călin; Crăciun, Maria

    2014-12-01

    Time series generated by a complex hierarchical system exhibit various types of dynamics at different time scales. A financial time series is an example of such a multiscale structure with time scales ranging from minutes to several years. In this paper we decompose the volatility of financial indices into five intrinsic components and we show that it has a heterogeneous scale structure. The small-scale components have a stochastic nature and they are independent 99% of the time, becoming synchronized during financial crashes and enhancing the heavy tails of the volatility distribution. The deterministic behavior of the large-scale components is related to the nonstationarity of the financial markets evolution. Our decomposition of the financial volatility is a superstatistical model more complex than those usually limited to a superposition of two independent statistics at well-separated time scales.

  13. Turbulent diffusion with memories and intrinsic shear

    NASA Technical Reports Server (NTRS)

    Tchen, C. M.

    1974-01-01

    The first part of the present theory is devoted to the derivation of a Fokker-Planck equation. The eddies smaller than the hydrodynamic scale of the diffusion cloud form a diffusivity, while the inhomogeneous, bigger eddies give rise to a nonuniform migratory drift. This introduces an eddy-induced shear which reflects on the large-scale diffusion. The eddy-induced shear does not require the presence of a permanent wind shear and is intrinsic to the diffusion. Secondly, a transport theory of diffusivity is developed by the method of repeated-cascade and is based upon a relaxation of a chain of memories with decreasing information. The full range of diffusion consists of inertia, composite, and shear subranges, for which variance and eddy diffusivities are predicted. The coefficients are evaluated. Comparison with experiments in the upper atmosphere and oceans is made.

  14. Quaternion Formalism for the Intrinsic Transfer Matrix

    NASA Astrophysics Data System (ADS)

    Cretu, Nicolae; Pop, Mihail Ioan; Boer, Attila

    A quaternion formulation is applied to the intrinsic transfer matrix for longitudinal elastic wave propagation through a multilayer medium in order to find the spectral response of a sonic crystal. Resonance conditions and the band structure of the crystal are obtained. The presence of a defect is also analysed. The analysis is carried out theoretically and through simulations. A coupled oscillators model is used to validate the obtained results from a phenomenological point of view. Experimental measurements are carried out for some periodic multilayer arrangements and they are correlated with theory. The obtained spectral response and band structure are essential in characterising the sonic crystal and also in optimising its structure in order to obtain specific passbands and stopbands. The adaptedness of the quaternion formulation to periodic structures and to the inclusion of defects is considered.

  15. 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.

  16. 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.

  17. 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

  18. Intrinsic radial sensitivity of nucleon inelastic scattering

    NASA Astrophysics Data System (ADS)

    Kelly, J. J.

    1988-02-01

    A linear expansion analysis of the folding model transition amplitude is used to study the intrinsic sensitivity of the inelastic scattering of intermediate energy nucleons to the radial form of the neutron transition density, given known proton transition densities from electron scattering. Realistic density-dependent effective interactions are used to construct pseudodata. These pseudodata are then reanalyzed and the error matrix is used to calculate an error band for the radial transition density. This approach reveals the sensitivity of the extracted transition density to absorption, medium modifications of the interaction, and the extent and quality of the data in a manner that is largely free of the residual inaccuracies in reaction theory that complicate the analysis of real data. We find that the intrinsic radial sensitivity of nucleon inelastic scattering is best for projectile energies between 200 and 500 MeV, but is adequate to resolve the radial dependence of neutron transition densities even in the interior of heavy nuclei throughout the energy regime 100-800 MeV. We have also compared our method with scale-factor analyses which assume proportionality between neutron and proton densities. For states whose transition densities are similar in the surface, we find scaling to be accurate at the 20% level. However, for light nuclei substantial deviations beyond the first peak of the differential cross section reveal sensitivity to shape differences. This sensitivity is reduced for heavy nuclei. The model dependence of radial densities is also studied. A high-q constraint is used to analyze the contribution of incompleteness error to the deduced error bands and to reduce the model dependence.

  19. 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

  20. Third Quantization and Quantum Universes

    NASA Astrophysics Data System (ADS)

    Kim, Sang Pyo

    2014-01-01

    We study the third quantization of the Friedmann-Robertson-Walker cosmology with N-minimal massless fields. The third quantized Hamiltonian for the Wheeler-DeWitt equation in the minisuperspace consists of infinite number of intrinsic time-dependent, decoupled oscillators. The Hamiltonian has a pair of invariant operators for each universe with conserved momenta of the fields that play a role of the annihilation and the creation operators and that construct various quantum states for the universe. The closed universe exhibits an interesting feature of transitions from stable states to tachyonic states depending on the conserved momenta of the fields. In the classical forbidden unstable regime, the quantum states have googolplex growing position and conjugate momentum dispersions, which defy any measurements of the position of the universe.

  1. 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.

  2. A new family of N dimensional superintegrable double singular oscillators and quadratic algebra Q(3) ⨁ so(n) ⨁ so(N-n)

    NASA Astrophysics Data System (ADS)

    Fazlul Hoque, Md; Marquette, Ian; Zhang, Yao-Zhong

    2015-11-01

    We introduce a new family of N dimensional quantum superintegrable models consisting of double singular oscillators of type (n, N-n). The special cases (2,2) and (4,4) have previously been identified as the duals of 3- and 5-dimensional deformed Kepler-Coulomb systems with u(1) and su(2) monopoles, respectively. The models are multiseparable and their wave functions are obtained in (n, N-n) double-hyperspherical coordinates. We obtain the integrals of motion and construct the finitely generated polynomial algebra that is the direct sum of a quadratic algebra Q(3) involving three generators, so(n), so(N-n) (i.e. Q(3) ⨁ so(n) ⨁ so(N-n)). The structure constants of the quadratic algebra itself involve the Casimir operators of the two Lie algebras so(n) and so(N-n). Moreover, we obtain the finite dimensional unitary representations (unirreps) of the quadratic algebra and present an algebraic derivation of the degenerate energy spectrum of the superintegrable model.

  3. 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.

  4. 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.

  5. Intrinsic antibiotic resistance: mechanisms, origins, challenges and solutions.

    PubMed

    Cox, Georgina; Wright, Gerard D

    2013-08-01

    The intrinsic antibiotic resistome is a naturally occurring phenomenon that predates antibiotic chemotherapy and is present in all bacterial species. In addition to the intrinsic resistance mediated by the bacterial outer membrane and active efflux, studies have shown that a surprising number of additional genes and genetic loci also contribute to this phenotype. Antibiotic resistance is rife in both the clinic and the environment; novel therapeutic strategies need to be developed in order to prevent a major global clinical threat. The possibility of inhibiting elements comprising the intrinsic resistome in bacterial pathogens offers the promise for repurposing existing antibiotics against intrinsically resistant bacteria. PMID:23499305

  6. Interventions for primary (intrinsic) tracheomalacia in children.

    PubMed

    Bohadana, Saramira Cardoso

    2013-01-01

    BACKGROUND Tracheomalacia, a disorder of the large airways where the trachea is deformed or malformed during respiration, is commonly seen in tertiary paediatric practice. It is associated with a wide spectrum of respiratory symptoms from life-threatening recurrent apnoea to common respiratory symptoms such as chronic cough and wheeze. Current practice following diagnosis of tracheomalacia includes medical approaches aimed at reducing associated symptoms of tracheomalacia, ventilation modalities of continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BiPAP), and surgical approaches aimed at improving the calibre of the airway (airway stenting, aortopexy, tracheopexy). OBJECTIVES To evaluate the efficacy of medical and surgical therapies for children with intrinsic (primary) tracheomalacia. METHODS Search The Cochrane Airways Group searched the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Airways Group's Specialized Register, Medline and Embase databases. The Cochrane Airways Group performed the latest searches in March 2012. Selection criteria All randomized controlled trials (RCTs) of therapies related to symptoms associated with primary or intrinsic tracheomalacia. Data collection and analysis Two reviewers extracted data from the included study independently and resolved disagreements by consensus. MAIN RESULTS We included one RCT that compared nebulized recombinant human deoxyribonuclease (rhDNase) with placebo in 40 children with airway malacia and a respiratory tract infection. We assessed it to be a RCT with overall low risk of bias. Data analyzed in this review showed that there was no significant difference between groups for the primary outcome of proportion cough-free at two weeks (odds ratio (OR) 1.38; 95% confidence interval (CI) 0.37 to 5.14). However, the mean change in night time cough diary scores significantly favoured the placebo group (mean difference (MD) 1.00; 95% CI 0.17 to 1.83, P = 0

  7. Intrinsic and dynamically generated scalar meson states

    NASA Astrophysics Data System (ADS)

    Shakin, C. M.; Wang, Huangsheng

    2001-01-01

    Recent work by Maltman has given us confidence that our assignment of scalar meson states to various nonets based upon our generalized Nambu-Jona-Lasinio (NJL) model is correct. [For example, in our model the a0(980) and the f0(980) are in the same nonet as the K*0(1430).] In this work we make use of our model to provide a precise definition of ``preexisting'' resonances and ``dynamically generated'' resonances when considering various scalar mesons. [This distinction has been noted by Meissner in his characterization of the f0(400-1200) as nonpreexisting.] We define preexisting (or intrinsic) resonances as those that appear as singularities of the qq¯ T matrix and are in correspondence with qq¯ states bound in the confining field. [Additional singularities may be found when studying the T matrices describing π-π or π-K scattering, for example. Such features may be seen to arise, in part, from t-channel and u-channel ρ exchange in the case of π-π scattering, leading to the introduction of the σ(500-600). In addition, threshold effects in the qq¯ T matrix can give rise to significant broad cross section enhancements. The latter is, in part, responsible for the introduction of the κ(900) in a study of π-K scattering, for example.] We suggest that it is only the intrinsic resonances which correspond to qq¯ quark-model states, and it is only the intrinsic states that are to be used to form quark-model qq¯ nonets of states. [While the κ(900) and σ(500-600) could be placed in a nonet of dynamically generated states, it is unclear whether there is evidence that requires the introduction of other members of such a nonet.] In this work we show how the phenomena related to the introduction of the σ(500-600) and the κ(900) are generated in studies of π-π and π-K scattering, making use of our generalized Nambu-Jona-Lasinio model. We also calculate the decay constants for the a0 and K*0 mesons and compare our results with those obtained by Maltman. We find

  8. Trees, bialgebras and intrinsic numerical algorithms

    NASA Technical Reports Server (NTRS)

    Crouch, Peter; Grossman, Robert; Larson, Richard

    1990-01-01

    Preliminary work about intrinsic numerical integrators evolving on groups is described. Fix a finite dimensional Lie group G; let g denote its Lie algebra, and let Y(sub 1),...,Y(sub N) denote a basis of g. A class of numerical algorithms is presented that approximate solutions to differential equations evolving on G of the form: dot-x(t) = F(x(t)), x(0) = p is an element of G. The algorithms depend upon constants c(sub i) and c(sub ij), for i = 1,...,k and j is less than i. The algorithms have the property that if the algorithm starts on the group, then it remains on the group. In addition, they also have the property that if G is the abelian group R(N), then the algorithm becomes the classical Runge-Kutta algorithm. The Cayley algebra generated by labeled, ordered trees is used to generate the equations that the coefficients c(sub i) and c(sub ij) must satisfy in order for the algorithm to yield an rth order numerical integrator and to analyze the resulting algorithms.

  9. 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)].

  10. 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

  11. Exploiting intrinsic fluctuations to identify model parameters.

    PubMed

    Zimmer, Christoph; Sahle, Sven; Pahle, Jürgen

    2015-04-01

    Parameterisation of kinetic models plays a central role in computational systems biology. Besides the lack of experimental data of high enough quality, some of the biggest challenges here are identification issues. Model parameters can be structurally non-identifiable because of functional relationships. Noise in measured data is usually considered to be a nuisance for parameter estimation. However, it turns out that intrinsic fluctuations in particle numbers can make parameters identifiable that were previously non-identifiable. The authors present a method to identify model parameters that are structurally non-identifiable in a deterministic framework. The method takes time course recordings of biochemical systems in steady state or transient state as input. Often a functional relationship between parameters presents itself by a one-dimensional manifold in parameter space containing parameter sets of optimal goodness. Although the system's behaviour cannot be distinguished on this manifold in a deterministic framework it might be distinguishable in a stochastic modelling framework. Their method exploits this by using an objective function that includes a measure for fluctuations in particle numbers. They show on three example models, immigration-death, gene expression and Epo-EpoReceptor interaction, that this resolves the non-identifiability even in the case of measurement noise with known amplitude. The method is applied to partially observed recordings of biochemical systems with measurement noise. It is simple to implement and it is usually very fast to compute. This optimisation can be realised in a classical or Bayesian fashion. PMID:26672148

  12. Intrinsic Disorder in the Kinesin Superfamily.

    PubMed

    Seeger, Mark A; Rice, Sarah E

    2013-09-01

    Kinesin molecular motors perform a myriad of intracellular transport functions. While their mechanochemical mechanisms are well understood and well-conserved throughout the superfamily, the cargo-binding and regulatory mechanisms governing the activity of kinesins are highly diverse and in general, are incompletely characterized. Here we present evidence from bioinformatic predictions indicating that most kinesin superfamily members contain significant regions of intrinsically disordered (ID) residues. ID regions can bind to multiple partners with high specificity, and are highly labile to post-translational modification and degradation signals. In kinesins, the predicted ID regions are primarily found in areas outside the motor domains, where primary sequences diverge by family, suggesting that ID may be a critical structural element for determining the functional specificity of individual kinesins. To support this idea, we present a systematic analysis of the kinesin superfamily, family by family, for predicted regions of ID. We combine this analysis with a comprehensive review of kinesin binding partners and post-translational modifications. We find two key trends across the entire kinesin superfamily. First, ID residues tend to be in the tail regions of kinesins, opposite the superfamily-conserved motor domains. Second, predicted ID regions correlate to regions that are known to bind to cargoes and/or undergo post-translational modifications. We therefore propose that ID is a structural element utilized by the kinesin superfamily in order to impart functional specificity to individual kinesins. PMID:24244223

  13. 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.

  14. 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.

  15. 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.

  16. Intrinsic and extrinsic mechanisms of oocyte loss.

    PubMed

    Thomson, Travis C; Fitzpatrick, Katherine E; Johnson, Joshua

    2010-12-01

    A great deal of evolutionary conservation has been found in the control of oocyte development, from invertebrates to women. However, little is known of mechanisms that control oocyte loss over time. Oocyte loss is often assumed to be a result of oocyte-intrinsic deficiencies or damage. In fruit flies, starvation results in halted oocyte production by germline stem cells and induces oocyte loss midway through development. When we fed wild-type flies the bacterial compound Rapamycin (RAP) to mimic starvation, production of new oocytes continued, but mid-stage loss sterilized the animals. Surprisingly, follicle cell invasion and phagocytosis of the oocyte preceded any signs of germ cell death. RAP-induced egg chamber loss was prevented when RAP receptor FKBP12 was knocked down specifically in follicle cells. Oogenesis continued past the mid-stages, and these mutants continued to lay embryos that could develop into normal adults. Hence, intact healthy oocytes can be destroyed by somatic cells responding to extrinsic stimuli. We termed this process inducible somatic oocyte destruction. RAP treatment of mouse follicles in vitro resulted in phagocytic uptake of the oocyte by granulosa cells as seen in flies. We hypothesize that extrinsic modes of oocyte loss occur in mammals. PMID:20651035

  17. Understanding Oceanic Migrations with Intrinsic Biogeochemical Markers

    PubMed Central

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

    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

  18. Regulation and aggregation of intrinsically disordered peptides

    PubMed Central

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

    2015-01-01

    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. PMID:25691742

  19. 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. PMID:25691742

  20. 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.

  1. 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

  2. Intrinsic and extrinsic psychosis in Parkinson's disease.

    PubMed

    Wolters, E C

    2001-09-01

    Direct and indirect signs and symptoms of Parkinson's disease are a major cause of disability in the elderly. Intrinsic symptoms comprise not only the well-known clinical hallmarks of this disease with motor behavioral abnormalities, such as bradykinesia, hypokinesia, rigidity and tremor, but also autonomic failure with orthostatic hypotension, urinal incontinence and impotence as well as non-motor behavioral abnormalities: mental dysfunction characterized by mood disorders, cognitive dysfunction and, sporadically, delusions and hallucinations. These symptoms are caused by a progressive abnormal degeneration of the dopamine (DA) producing cells in the substantia nigra (SN) and ventral tegmentum area (VTA) in combination with an interindividual fluctuating degree of decay in the noradrenergic (locus coeruleus), cholinergic forebrain (nucleus basalis of Meynert) and serotoninergic (dorsal raphe nuclei) systems. Extrinsic symptoms, induced by pharmacotherapy, mainly manifest with (un)predictable motor response fluctuations and dopaminomimetic psychosis. Psychological and psychiatric symptoms in Parkinson's disease (PD) are important predictors of the patient's quality of life. As these symptoms are potentially treatable, identification is of major clinical importance both for the patients and their caregivers and may enable to maintain Parkinson's disease patients at home for a longer period. PMID:11697684

  3. Intrinsic Disorder in the Kinesin Superfamily

    PubMed Central

    Seeger, Mark A.; Rice, Sarah E.

    2012-01-01

    Kinesin molecular motors perform a myriad of intracellular transport functions. While their mechanochemical mechanisms are well understood and well-conserved throughout the superfamily, the cargo-binding and regulatory mechanisms governing the activity of kinesins are highly diverse and in general, are incompletely characterized. Here we present evidence from bioinformatic predictions indicating that most kinesin superfamily members contain significant regions of intrinsically disordered (ID) residues. ID regions can bind to multiple partners with high specificity, and are highly labile to post-translational modification and degradation signals. In kinesins, the predicted ID regions are primarily found in areas outside the motor domains, where primary sequences diverge by family, suggesting that ID may be a critical structural element for determining the functional specificity of individual kinesins. To support this idea, we present a systematic analysis of the kinesin superfamily, family by family, for predicted regions of ID. We combine this analysis with a comprehensive review of kinesin binding partners and post-translational modifications. We find two key trends across the entire kinesin superfamily. First, ID residues tend to be in the tail regions of kinesins, opposite the superfamily-conserved motor domains. Second, predicted ID regions correlate to regions that are known to bind to cargoes and/or undergo post-translational modifications. We therefore propose that ID is a structural element utilized by the kinesin superfamily in order to impart functional specificity to individual kinesins. PMID:24244223

  4. 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. PMID:24246059

  5. Surgical Treatment Guidelines for Digital Deformity Associated With Intrinsic Muscle Spasticity (Intrinsic Plus Foot) in Adults With Cerebral Palsy.

    PubMed

    Boffeli, Troy J; Collier, Rachel C

    2015-01-01

    Intrinsic plus foot deformity has primarily been associated with cerebral palsy and involves spastic contracture of the intrinsic musculature with resultant toe deformities. Digital deformity is caused by a dynamic imbalance between the intrinsic muscles in the foot and extrinsic muscles in the lower leg. Spastic contracture of the toes frequently involves curling under of the lesser digits or contracture of the hallux into valgus or plantarflexion deformity. Patients often present with associated pressure ulcers, deformed toenails, shoe or brace fitting challenges, and pain with ambulation or transfers. Four different patterns of intrinsic plus foot deformity have been observed by the authors that likely relate to the different patterns of muscle involvement. Case examples are provided of the 4 patterns of intrinsic plus foot deformity observed, including global intrinsic plus lesser toe deformity, isolated intrinsic plus lesser toe deformity, intrinsic plus hallux valgus deformity, and intrinsic plus hallux flexus deformity. These case examples are presented to demonstrate each type of deformity and our approach for surgical management according to the contracture pattern. The surgical approach has typically involved tenotomy, capsulotomy, or isolated joint fusion. The main goals of surgical treatment are to relieve pain and reduce pressure points through digital realignment in an effort to decrease the risk of pressure sores and allow more effective bracing to ultimately improve the patient's mobility. PMID:25154656

  6. 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

  7. 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

  8. 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…

  9. Extrinsic and Intrinsic Motivation at 30: Unresolved Scientific Issues

    ERIC Educational Resources Information Center

    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…

  10. Intrinsic Motivation--An Overlooked Basis for Evaluation.

    ERIC Educational Resources Information Center

    Iso-Ahola, Seppo E.

    1982-01-01

    Intrinsic motivation is discussed as the main concern of evaluation of leisure and recreational programs. Two factors influencing leisure behavior are perceived freedom and perceived competence. Two types of intrinsic rewards are possible from leisure participation: rewards and those obtained from a change in environment. Evaluation should then…

  11. 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…

  12. A halo model for intrinsic alignments of galaxy ellipticities

    NASA Astrophysics Data System (ADS)

    Schneider, Michael D.; Bridle, Sarah

    2010-03-01

    Correlations between intrinsic ellipticities of galaxies are a potentially important systematic error when constraining dark energy properties from weak gravitational lensing (cosmic shear) surveys. In the absence of perfectly known galaxy redshifts, some modelling of the galaxy intrinsic alignments is likely to be required to extract the lensing signal to sufficient accuracy. We present a new model based on the placement of galaxies into dark matter haloes. The central galaxy ellipticity follows the large-scale potential and, in the simplest case, the satellite galaxies point at the halo centre. The two-halo term is then dominated by the linear-alignment model and the one-halo term provides a motivated extension of intrinsic alignment models to small scales. We provide fitting formulae for the spatial projected source power spectra for both intrinsic-intrinsic (II) and gravitational-intrinsic (GI) correlations. We illustrate the potential impact of ignoring intrinsic alignments on cosmological parameter constraints from non-tomographic surveys, finding that σ8 could be underestimated by up to the size of the current 1σ error bar from cosmic shear if very small scales are included in the analysis. Finally, we highlight areas of interest for numerical simulations of dark matter clustering and galaxy formation that can further constrain the intrinsic alignment signal.

  13. 46 CFR 111.105-11 - Intrinsically safe systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Intrinsically safe systems. 111.105-11 Section 111.105-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-11 Intrinsically safe systems. (a) Each system required by this subpart to be...

  14. 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…

  15. 30 CFR 18.68 - Tests for intrinsic safety.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Tests for intrinsic safety. 18.68 Section 18.68 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.68 Tests for intrinsic safety....

  16. 30 CFR 18.68 - Tests for intrinsic safety.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests for intrinsic safety. 18.68 Section 18.68 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.68 Tests for intrinsic safety....

  17. 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…

  18. 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…

  19. Can Education Be Made "Intrinsically Interesting" to Children?

    ERIC Educational Resources Information Center

    Condry, John; Koslowski, Barbara

    This paper reviews the role of intrinsic and extrinsic motivation in children's learning. The paper contends that two types of learning exist: self-initiated learning which is intrinsically motivated, and learning initiated by another person which involves external rewards. The paper suggests that motivation is not unidimensional and that task…

  20. Some toy sheet universes

    NASA Astrophysics Data System (ADS)

    Hamerský, Jaroslav; Langer, Jiří

    2012-07-01

    Our model is based on the model studied by Langer [1] and in more detail by Langer and Žofka [2]. In these papers we studied a toy closed universe which is flat except of a thin spherical shell. The model was constructed in the framework of the Israel formalism [3]. In this approach the history of a thin shell of matter is described by the time-like hypersurface Σ which divides the spacetime into two parts V- and V+. The hypersuface Σ is a common boundary of V- and V+ consequently its intrinsic metric induced by the geometries in both regions must be the same. However, the extrinsic curvatures of Σ in V- and V+ are in general different. The jump in projections of the extrinsic curvature tensors on Σ determines the surface energy-momentum tensor of matter on Σ.

  1. Efficient Estimation of Time-Varying Intrinsic and Reflex Stiffness

    PubMed Central

    Ludvig, Daniel; Perreault, Eric J.; Kearney, Robert E.

    2013-01-01

    Dynamic joint stiffness defines the dynamic relationship between the position of the joint and the torque acting about it; hence it is important in the control of movement and posture. Joint stiffness consists of two components: intrinsic stiffness and reflex stiffness. Measuring intrinsic and reflex torques directly is not possible, thus estimating intrinsic and reflex stiffness is challenging. A further complication is that both intrinsic and reflex stiffness vary with joint position and torque. Thus, the measurement of dynamic joint stiffness during movement requires a time-varying algorithm. Recently we described an algorithm to estimate time-varying intrinsic and reflex stiffness and demonstrated its application. This paper describes modifications to that algorithm that significantly improves the accuracy of the estimates it generates while increasing its computational efficiency by a factor of seven. PMID:22255247

  2. Ethnic stigma, academic anxiety, and intrinsic motivation in middle childhood.

    PubMed

    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 that ethnic-minority children reported higher stigma awareness than European American children. For all children, stigma awareness was associated with higher academic anxiety and lower intrinsic motivation. Despite these associations, ethnic-minority children reported higher levels of intrinsic motivation than their European American peers. A significant portion of the higher intrinsic motivation among Dominican students was associated with their higher levels of school belonging, suggesting that supportive school environments may be important sources of intrinsic motivation among some ethnic-minority children. PMID:21883152

  3. 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.

  4. 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.

  5. Intrinsic organization of the anesthetized brain.

    PubMed

    Liang, Zhifeng; King, Jean; Zhang, Nanyin

    2012-07-25

    The neural mechanism of unconsciousness has been a major unsolved question in neuroscience despite its vital role in brain states like coma and anesthesia. The existing literature suggests that neural connections, information integration, and conscious states are closely related. Indeed, alterations in several important neural circuitries and networks during unconscious conditions have been reported. However, how the whole-brain network is topologically reorganized to support different patterns of information transfer during unconscious states remains unknown. Here we directly compared whole-brain neural networks in awake and anesthetized states in rodents. Consistent with our previous report, the awake rat brain was organized in a nontrivial manner and conserved fundamental topological properties in a way similar to the human brain. Strikingly, these topological features were well maintained in the anesthetized brain. Local neural networks in the anesthetized brain were reorganized with altered local network properties. The connectional strength between brain regions was also considerably different between the awake and anesthetized conditions. Interestingly, we found that long-distance connections were not preferentially reduced in the anesthetized condition, arguing against the hypothesis that loss of long-distance connections is characteristic to unconsciousness. These findings collectively show that the integrity of the whole-brain network can be conserved between widely dissimilar physiologic states while local neural networks can flexibly adapt to new conditions. They also illustrate that the governing principles of intrinsic brain organization might represent fundamental characteristics of the healthy brain. With the unique spatial and temporal scales of resting-state fMRI, this study has opened a new avenue for understanding the neural mechanism of (un)consciousness. PMID:22836253

  6. New concept to break the intrinsic properties of organic semiconductors for optical sensing applications

    NASA Astrophysics Data System (ADS)

    Choy, Wallace C. H.

    2015-09-01

    As the intrinsic electrostatic limit, space charge limit (SCL) for photocurrent is a universal phenomenon which is fundamental important for organic semiconductors. We will demonstrate SCL breaking by a new plasmonic-electrical concept. As a proof-ofconcept, organic solar cells (OSCs) comprising metallic planar and grating electrodes are studied. Interestingly, although strong plasmonic resonances induce abnormally dense photocarriers around a grating anode, the grating incorporated inverted OSC is exempt from space charge accumulation (limit) and degradation of electrical properties. The plasmonic-electrical concept will open up a new way to manipulate both optical and electrical properties of semiconductor devices simultaneously.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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)…

  16. 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)

  17. 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.

  18. 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.

  19. 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

  20. 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.

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

    SciTech Connect

    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.

  2. 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

  3. Intrinsic adhesion force of lubricants to steel surface.

    PubMed

    Lee, Jonghwi

    2004-09-01

    The intrinsic adhesion forces of lubricants and other pharmaceutical materials to a steel surface were quantitatively compared using Atomic Force Microscopy (AFM). A steel sphere was attached to the tip of an AFM cantilever, and its adhesion forces to the substrate surfaces of magnesium stearate, sodium stearyl fumarate, lactose, 4-acetamidophenol, and naproxen were measured. Surface roughness varied by an order of magnitude among the materials. However, the results clearly showed that the two lubricants had about half the intrinsic adhesion force as lactose, 4-acetamidophenol, and naproxen. Differences in the intrinsic adhesion forces of the two lubricants were insignificant. The lubricant molecules were unable to cover the steel surface during AFM measurements. Intrinsic adhesion force can slightly be modified by surface treatment and compaction, and its tip-to-tip variation was not greater than its difference between lubricants and other pharmaceutical particles. This study provides a quantitative fundamental basis for understanding adhesion related issues. PMID:15295791

  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. Trapped electron mode turbulence driven intrinsic rotation in Tokamak plasmas.

    PubMed

    Wang, W X; Hahm, T S; Ethier, S; Zakharov, L E; Diamond, P H

    2011-02-25

    Progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal plasmas is reported. The turbulence-driven intrinsic torque associated with nonlinear residual stress generation due to zonal flow shear induced asymmetry in the parallel wave number spectrum is shown to scale close to linearly with plasma gradients and the inverse of the plasma current, qualitatively reproducing experimental empirical scalings of intrinsic rotation. The origin of current scaling is found to be enhanced k(∥) symmetry breaking induced by the increased radial variation of the safety factor as the current decreases. The intrinsic torque is proportional to the pressure gradient because both turbulence intensity and zonal flow shear, which are two key ingredients for driving residual stress, increase with turbulence drive, which is R/L(T(e)) and R/L(n(e)) for the trapped electron mode. PMID:21405577

  6. What is Intrinsic Motivation? A Typology of Computational Approaches

    PubMed Central

    Oudeyer, Pierre-Yves; Kaplan, Frederic

    2007-01-01

    Intrinsic motivation, centrally involved in spontaneous exploration and curiosity, is a crucial concept in developmental psychology. It has been argued to be a crucial mechanism for open-ended cognitive development in humans, and as such has gathered a growing interest from developmental roboticists in the recent years. The goal of this paper is threefold. First, it provides a synthesis of the different approaches of intrinsic motivation in psychology. Second, by interpreting these approaches in a computational reinforcement learning framework, we argue that they are not operational and even sometimes inconsistent. Third, we set the ground for a systematic operational study of intrinsic motivation by presenting a formal typology of possible computational approaches. This typology is partly based on existing computational models, but also presents new ways of conceptualizing intrinsic motivation. We argue that this kind of computational typology might be useful for opening new avenues for research both in psychology and developmental robotics. PMID:18958277

  7. Intrinsic Inhomogeneity and Multiscale Functionality in Transition Metal Oxides

    NASA Astrophysics Data System (ADS)

    Bishop, A. R.

    2003-06-01

    We briefly review a perspective of transition metal oxides as correlated electron materials governed by functional multiscale complexity. We emphasize several themes: the prevalence of intrinsic complexity realized in the coexistence or competition among broken-symmetry ground states; the origin of landscapes in coupled spin, charge and lattice (orbital) degrees-of-freedom; the importance of co-existing short- and long-range forces; and the importance of multiscale complexity for key material properties, including hierarchies of functional, connected scales, coupled intrinsic inhomogeneities in spin, charge and lattice, consequent intrinsic multiple timescales, and the importance of multifunctional "electro-elastic" materials. Finally, we suggest that such intrinsic multiscale features are characteristic of wide classes of inorganic, organic, and biological matter.

  8. The role of intrinsic motivations in attention allocation and shifting

    PubMed Central

    Di Nocera, Dario; Finzi, Alberto; Rossi, Silvia; Staffa, Mariacarla

    2014-01-01

    The concepts of attention and intrinsic motivations are of great interest within adaptive robotic systems, and can be exploited in order to guide, activate, and coordinate multiple concurrent behaviors. Attention allocation strategies represent key capabilities of human beings, which are strictly connected with action selection and execution mechanisms, while intrinsic motivations directly affect the allocation of attentional resources. In this paper we propose a model of Reinforcement Learning (RL), where both these capabilities are involved. RL is deployed to learn how to allocate attentional resources in a behavior-based robotic system, while action selection is obtained as a side effect of the resulting motivated attentional behaviors. Moreover, the influence of intrinsic motivations in attention orientation is obtained by introducing rewards associated with curiosity drives. In this way, the learning process is affected not only by goal-specific rewards, but also by intrinsic motivations. PMID:24744746

  9. The intrinsic vasculature of the cat facial nerve.

    PubMed

    Balkany, T

    1986-01-01

    Treatment of facial nerve disorders is based in part on assumptions regarding the intrinsic blood supply of the nerve. This study was designed to comprehensively delineate the intrinsic facial nerve microcirculation and its relation to the extrinsic circulation in an animal model. Twenty-eight cat facial nerves were removed intact from brain stem to stylomastoid foramen following intravital fixation. Specimens were studied by gross dissection, silicone injection and tissue clearing, complete vessel counts on serial cross sections of individual nerves, and scanning electron microscopy or transmission electron microscopy. The labyrinthine segment of the cat facial nerve contains strikingly fewer intrinsic blood vessels than the mastoid and tympanic segments. The geniculate ganglion, however, has a distinct, rich vascular plexus. The ultrastructure of the intrinsic facial nerve vessels is similar to other small vessels of the body with tight junctions of the endothelium and overlapping spiral smooth muscle fibers of arterioles, as well as surrounding pericytes. PMID:3510355

  10. Intrinsic Obstetric Palsy: Case Report and Literature Review.

    PubMed

    Hakeem, Rashida; Neppe, Cliff

    2016-04-01

    Maternal neurological injuries may be intrinsic to the labour and delivery process or may result directly or indirectly from obstetric or anaesthetic intervention. This intrinsic obstetric palsy is a rare complication of labour but can have devastating impact on a previously healthy mother. A 23-year-old gravida1, para0 who had epidural for labour analgesia, was augmented for slow progress and had a normal vaginal delivery. She was diagnosed post delivery with intrinsic obstetric palsy involving several peripheral nerves and lumbosacral nerve roots with a guarded prognosis. In this article we have discussed the risk factors and mechanisms of intrinsic obstetric palsy and proposed further investigation into the potential protective role of ambulatory analgesia i.e. CSE (Combined Spinal Epidural) or LDI (Low Dose Infusion). PMID:27190901

  11. 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.

  12. Intrinsic Obstetric Palsy: Case Report and Literature Review

    PubMed Central

    Neppe, Cliff

    2016-01-01

    Maternal neurological injuries may be intrinsic to the labour and delivery process or may result directly or indirectly from obstetric or anaesthetic intervention. This intrinsic obstetric palsy is a rare complication of labour but can have devastating impact on a previously healthy mother. A 23-year-old gravida1, para0 who had epidural for labour analgesia, was augmented for slow progress and had a normal vaginal delivery. She was diagnosed post delivery with intrinsic obstetric palsy involving several peripheral nerves and lumbosacral nerve roots with a guarded prognosis. In this article we have discussed the risk factors and mechanisms of intrinsic obstetric palsy and proposed further investigation into the potential protective role of ambulatory analgesia i.e. CSE (Combined Spinal Epidural) or LDI (Low Dose Infusion). PMID:27190901

  13. A collection of intrinsic disorder characterizations from eukaryotic proteomes.

    PubMed

    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

  14. Universal Memcomputing Machines.

    PubMed

    Traversa, Fabio Lorenzo; Di Ventra, Massimiliano

    2015-11-01

    We introduce the notion of universal memcomputing machines (UMMs): a class of brain-inspired general-purpose computing machines based on systems with memory, whereby processing and storing of information occur on the same physical location. We analytically prove that the memory properties of UMMs endow them with universal computing power (they are Turing-complete), intrinsic parallelism, functional polymorphism, and information overhead, namely, their collective states can support exponential data compression directly in memory. We also demonstrate that a UMM has the same computational power as a nondeterministic Turing machine, namely, it can solve nondeterministic polynomial (NP)-complete problems in polynomial time. However, by virtue of its information overhead, a UMM needs only an amount of memory cells (memprocessors) that grows polynomially with the problem size. As an example, we provide the polynomial-time solution of the subset-sum problem and a simple hardware implementation of the same. Even though these results do not prove the statement NP = P within the Turing paradigm, the practical realization of these UMMs would represent a paradigm shift from the present von Neumann architectures, bringing us closer to brain-like neural computation. PMID:25667360

  15. 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

  16. 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.

  17. 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

  18. Direct measurement of the intrinsic ankle stiffness during standing.

    PubMed

    Vlutters, M; Boonstra, T A; Schouten, A C; van der Kooij, H

    2015-05-01

    Ankle stiffness contributes to standing balance, counteracting the destabilizing effect of gravity. The ankle stiffness together with the compliance between the foot and the support surface make up the ankle-foot stiffness, which is relevant to quiet standing. The contribution of the intrinsic ankle-foot stiffness to balance, and the ankle-foot stiffness amplitude dependency remain a topic of debate in the literature. We therefore developed an experimental protocol to directly measure the bilateral intrinsic ankle-foot stiffness during standing balance, and determine its amplitude dependency. By applying fast (40 ms) ramp-and-hold support surface rotations (0.005-0.08 rad) during standing, reflexive contributions could be excluded, and the amplitude dependency of the intrinsic ankle-foot stiffness was investigated. Results showed that reflexive activity could not have biased the torque used for estimating the intrinsic stiffness. Furthermore, subjects required less recovery action to restore balance after bilateral rotations in opposite directions compared to rotations in the same direction. The intrinsic ankle-foot stiffness appears insufficient to ensure balance, ranging from 0.93±0.09 to 0.44±0.06 (normalized to critical stiffness 'mgh'). This implies that changes in muscle activation are required to maintain balance. The non-linear stiffness decrease with increasing rotation amplitude supports the previous published research. With the proposed method reflexive effects can be ruled out from the measured torque without any model assumptions, allowing direct estimation of intrinsic stiffness during standing. PMID:25843262

  19. 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.

  20. Plasma universe

    SciTech Connect

    Alfven, H.

    1986-09-01

    A model based on the emissions and behavior of the most prevalent material in the universe leads one to view the world as an active and rapidly changing place, and helps one analyze the development of its components.

  1. 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)

  2. 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)

  3. Eternal Universe

    NASA Astrophysics Data System (ADS)

    Wetterich, C.

    2014-08-01

    We discuss cosmological models for an eternal Universe. Physical observables show no singularity from the infinite past to the infinite future. While the Universe is evolving, there is no beginning and no end—the Universe exists forever. The early state of inflation is described in two different, but equivalent pictures. In the freeze frame the Universe emerges from an almost static state with flat geometry. After entropy production it shrinks and "thaws" slowly from a "freeze state" with extremely low temperature. The field transformation to the second "big bang picture" (Einstein frame) is singular. This "field singularity" is responsible for an apparent singularity of the big bang. Furthermore, we argue that past-incomplete geodesics do not necessarily indicate a singularity or beginning of the Universe. Proper time ceases to be a useful concept for physical time if particles become massless. We propose to define physical time by counting the number of zeros of a component of the wave function. This counting is independent of the choice of coordinates and frames, and applies to massive and massless particles alike.

  4. 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%.

  5. 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

  6. 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

  7. Effects of Optical Blur Reduction on Equivalent Intrinsic Blur

    PubMed Central

    Valeshabad, Ali Kord; Wanek, Justin; McAnany, J. Jason; Shahidi, Mahnaz

    2015-01-01

    Purpose To determine the effect of optical blur reduction on equivalent intrinsic blur, an estimate of the blur within the visual system, by comparing optical and equivalent intrinsic blur before and after adaptive optics (AO) correction of wavefront error. Methods Twelve visually normal individuals (age; 31 ± 12 years) participated in this study. Equivalent intrinsic blur (σint) was derived using a previously described model. Optical blur (σopt) due to high-order aberrations was quantified by Shack-Hartmann aberrometry and minimized using AO correction of wavefront error. Results σopt and σint were significantly reduced and visual acuity (VA) was significantly improved after AO correction (P ≤ 0.004). Reductions in σopt and σint were linearly dependent on the values before AO correction (r ≥ 0.94, P ≤ 0.002). The reduction in σint was greater than the reduction in σopt, although it was marginally significant (P = 0.05). σint after AO correlated significantly with σint before AO (r = 0.92, P < 0.001) and the two parameters were related linearly with a slope of 0.46. Conclusions Reduction in equivalent intrinsic blur was greater than the reduction in optical blur due to AO correction of wavefront error. This finding implies that VA in subjects with high equivalent intrinsic blur can be improved beyond that expected from the reduction in optical blur alone. PMID:25785538

  8. 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.

  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. PMID:26277005

  10. Intrinsic bioremediation modeling to support Superfund site closure

    SciTech Connect

    Bedard, A.H.; Day, M.J.; Johnson, R.H.; Ritter, K.J.; Stancel, S.G.; Thomson, J.A.M.

    1997-09-01

    Closure of the groundwater component of a major Superfund site has been accomplished by a combination of source control, engineered in-situ bioremediation, and subsequent long-term intrinsic bioremediation. Engineered bioremediation outside the source control area resulted in very significant contaminant mass removal. This allowed intrinsic bioremediation to be considered as a passive remedial management method of achieving cleanup objectives after active remediation needed. Modeling demonstrated that intrinsic bioremediation would achieve cleanup objectives (for this site, Federal drinking water standards) within ten years of shutdown of the active bioremediation system. Modeling showed that residual electron acceptors and nutrients distributed in the aquifer during engineered bioremediation greatly enhance the intrinsic bioremediation process. The results of the modeling effort led to the active system being shut down a year ahead of schedule, allowing the project to move into a low-maintenance intrinsic bioremediation and long-term monitoring phase. The modeling demonstration coupled Visual MODFLOW{copyright} and BioTrans{copyright} to simulate groundwater flow, solute transport, and oxygen-limited, multi-species biodegradation. Regional flow evaluation, detailed model sensitivity analyses, and subarea modeling were employed to provide support to model predictions. Predictions will be tested by subsequent progress and compliance monitoring. Site closure began in early 1996.

  11. Mechanisms of intrinsic tone in ferret vascular smooth muscle.

    PubMed Central

    Pawlowski, J; Morgan, K G

    1992-01-01

    1. Circular strips from ferret aorta were used to investigate the mechanism of the intrinsic basal tone. 2. Determinations of stiffness using small sinusoidal length changes showed an abolition of both stiffness and force with cooling, but the temperature dependence of the change in active stiffness did not parallel that of force. At temperatures below 22 degrees C there appeared to be a relatively large population of attached, non-force-generating cross-bridges, indicating that separate mechanisms are involved in regulating cross-bridge attachment and the force per cross-bridge. 3. Active intrinsic tone was not affected by removal of extracellular Ca2+ or removal of endothelium. 4. Intracellular ionized Ca2+ concentrations ([Ca2+]i) as measured with the photoprotein aequorin, did not significantly change when intrinsic tone was abolished by cooling. 5. Myosin light chain phosphorylation, as measured by 2-dimensional polyacrylamide gel electrophoresis, significantly decreased on cooling, but the temperature dependence of phosphorylation did not parallel that of force. The change in phosphorylation in the absence of a change in [Ca2+]i suggests the presence of a constitutively active Ca(2+)-independent form of myosin light chain kinase. 6. Maximal concentrations of staurosporine inhibited but did not eliminate intrinsic tone. 7. Changes in myosin light chain kinase and protein kinase C activities may explain part but not all of the intrinsic tone. PMID:1593466

  12. 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.

  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. 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

  15. 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.

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

    NASA Astrophysics Data System (ADS)

    Chisari, Nora Elisa; Dvorkin, Cora

    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 & 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 fNL = 10, is only marginally significant in the intrinsic alignments signal with signal-to-noise ratios < 2 for the three surveys considered.

  17. 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. PMID:26386901

  18. 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

  19. 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

  20. Molecular Recognition by Templated Folding of an Intrinsically Disordered Protein

    NASA Astrophysics Data System (ADS)

    Toto, Angelo; Camilloni, Carlo; Giri, Rajanish; Brunori, Maurizio; Vendruscolo, Michele; Gianni, Stefano

    2016-02-01

    Intrinsically disordered proteins often become structured upon interacting with their partners. The mechanism of this ‘folding upon binding’ process, however, has not been fully characterised yet. Here we present a study of the folding of the intrinsically disordered transactivation domain of c-Myb (c-Myb) upon binding its partner KIX. By determining the structure of the folding transition state for the binding of wild-type and three mutational variants of KIX, we found a remarkable plasticity of the folding pathway of c-Myb. To explain this phenomenon, we show that the folding of c-Myb is templated by the structure of KIX. This adaptive folding behaviour, which occurs by heterogeneous nucleation, differs from the robust homogeneous nucleation typically observed for globular proteins. We suggest that this templated folding mechanism may enable intrinsically disordered proteins to achieve specific and reliable binding with multiple partners while avoiding aberrant interactions.

  1. 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

  2. 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

  3. 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}).

  4. Can observed randomness be certified to be fully intrinsic?

    PubMed

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

    2014-03-14

    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. PMID:24679271

  5. 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

  6. Social categories as markers of intrinsic interpersonal obligations.

    PubMed

    Rhodes, Marjorie; Chalik, Lisa

    2013-06-01

    Social categorization is an early-developing feature of human social cognition, yet the role that social categories play in children's understanding of and predictions about human behavior has been unclear. In the studies reported here, we tested whether a foundational functional role of social categories is to mark people as intrinsically obligated to one another (e.g., obligated to protect rather than harm). In three studies, children (aged 3-9, N = 124) viewed only within-category harm as violating intrinsic obligations; in contrast, they viewed between-category harm as violating extrinsic obligations defined by explicit rules. These data indicate that children view social categories as marking patterns of intrinsic interpersonal obligations, suggesting that a key function of social categories is to support inferences about how people will relate to members of their own and other groups. PMID:23613213

  7. 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

  8. University Citizenship.

    ERIC Educational Resources Information Center

    Kleinsasser, Audrey M.

    2002-01-01

    When called to serve on committees and take on other assignments outside their job descriptions, many educators run in the other direction. How can this work be reframed so educators can play a positive and active role as university citizens? This kind of involvement must be nurtured by all those on campus who play a leadership role. (Author)

  9. Universal Design.

    ERIC Educational Resources Information Center

    Rydeen, James E.

    1999-01-01

    Examines universal school design that is both user-friendly for all students and compliant with the Americans with Disabilities Act. This approach provides the basic functional design issues for easy traffic control, as well as orientation and classrooms that are adaptable to future curricular changes. Discusses new standards that impact design…

  10. New Universities

    ERIC Educational Resources Information Center

    Burgett, Bruce

    2011-01-01

    The public-private alliance signals a future in which self-serving agreements could become the coin of the realm. Such a future would be a betrayal of the historical promise of public universities to innovate in ways that expand access to higher education. Given the rise of market-based models in educational policy circles, the threat of the…

  11. 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…

  12. 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…

  13. 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…

  14. The role of protein intrinsic disorder in major psychiatric disorders.

    PubMed

    Tovo-Rodrigues, Luciana; Recamonde-Mendoza, Mariana; Paixão-Côrtes, Vanessa Rodrigues; Bruxel, Estela M; Schuch, Jaqueline B; Friedrich, Deise C; Rohde, Luis A; Hutz, Mara H

    2016-09-01

    Although new candidate genes for Autism Spectrum Disorder (ASD), Schizophrenia (SCZ), Attention-Deficit/Hyperactivity Disorder (ADHD), and Bipolar Disorder (BD) emerged from genome-wide association studies (GWAS), their underlying molecular mechanisms remain poorly understood. Evidences of the involvement of intrinsically disordered proteins in diseases have grown in the last decade. These proteins lack tridimensional structure under physiological conditions and are involved in important cellular functions such as signaling, recognition and regulation. The aim of the present study was to identify the role and abundance of intrinsically disordered proteins in a set of psychiatric diseases and to test whether diseases are different regarding protein intrinsic disorder. Our hypothesis is that differences across psychiatric illnesses phenotypes and symptoms may arise from differences in intrinsic protein disorder content and properties of each group. A bioinformatics prediction of intrinsic disorder was performed in proteins retrieved based on top findings from GWAS, Copy Number Variation and candidate gene investigations for each disease. This approach revealed that about 80% of studied proteins presented long stretches of disorder. This amount was significantly higher than that observed in general eukaryotic proteins, and those involved in cardiovascular diseases. These results suggest that proteins with intrinsic disorder are a common feature of neurodevelopment and synaptic transmission processes which are potentially involved in the etiology of psychiatric diseases. Moreover, we identified differences between ADHD and ASD when the binary prediction of structure and putative binding sites were compared. These differences may be related to variation in symptom complexity between both diseases. © 2016 Wiley Periodicals, Inc. PMID:27184105

  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 defect formation in peptide self-assembly

    NASA Astrophysics Data System (ADS)

    Deng, Li; Zhao, Yurong; Xu, Hai; Wang, Yanting

    2015-07-01

    In contrast to extensively studied defects in traditional materials, we report here a systematic investigation of the formation mechanism of intrinsic defects in self-assembled peptide nanostructures. The Monte Carlo simulations with our simplified dynamic hierarchical model revealed that the symmetry breaking of layer bending mode at the two ends during morphological transformation is responsible for intrinsic defect formation, whose microscopic origin is the mismatch between layer stacking along the side-chain direction and layer growth along the hydrogen bond direction. Moreover, defect formation does not affect the chirality of the self-assembled structure, which is determined by the initial steps of the peptide self-assembly process.

  17. Organizational, Nonorganizational, and Intrinsic religiosity and academic dishonesty.

    PubMed

    Storch, E A; Storch, J B

    2001-04-01

    The present study was a preliminary examination of the relations among the Organizational, Nonorganizational, and Intrinsic dimensions of religiosity and academic dishonesty. 244 college students completed the Duke Religion Index and nine questions assessing academic dishonesty. Analysis indicated that (1) regardless of sex, High Nonorganizational and Intrinsic religiosity was associated with lower reported rates of academic dishonesty, and (2) there was an interaction between Organizational religiosity and sex, with High Organizational women and men reporting similar rates of academic dishonesty. Furthermore, the frequency of academic dishonesty reported by High Organizational women was higher than the rates reported by Moderate and Minimal Organizational women. PMID:11351905

  18. Emission of terahertz waves from stacks of intrinsic Josephson junctions.

    SciTech Connect

    Gray, K. E.; Koshelev, A. E.; Kurter, C.; Kadowaki, K.; Yamamoto, T.; Minami, H.; Yamaguchi, H.; Tachiki, M.; Kwok, W.-K.; Welp, U.; Materials Science Division; Izmir Inst. of Tech.; Univ. Tsukuba; Univ. Tokyo

    2009-06-01

    By patterning mesoscopic crystals of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (BSCCO) into electromagnetic resonators the oscillations of a large number of intrinsic Josephson junctions can be synchronized into a macroscopic coherent state accompanied by the emission of strong continuous wave THz-radiation. The temperature dependence of the emission is governed by the interplay of self-heating in the resonator and by re-trapping of intrinsic Josephson junctions which can yield a strongly non-monotonic temperature dependence of the emission power. Furthermore, proper shaping of the resonators yields THz-sources with voltage-tunable emission frequencies.

  19. 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.

  20. 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.

  1. Minute Time Scale Prolyl Isomerization Governs Antibody Recognition of an Intrinsically Disordered Immunodominant Epitope*

    PubMed Central

    Fassolari, Marisol; Chemes, Lucia B.; Gallo, Mariana; Smal, Clara; Sánchez, Ignacio E.; de Prat-Gay, Gonzalo

    2013-01-01

    Conformational rearrangements in antibody·antigen recognition are essential events where kinetic discrimination of isomers expands the universe of combinations. We investigated the interaction mechanism of a monoclonal antibody, M1, raised against E7 from human papillomavirus, a prototypic viral oncoprotein and a model intrinsically disordered protein. The mapped 12-amino acid immunodominant epitope lies within a “hinge” region between the N-terminal intrinsically disordered and the C-terminal globular domains. Kinetic experiments show that despite being within an intrinsically disordered region, the hinge E7 epitope has at least two populations separated by a high energy barrier. Nuclear magnetic resonance traced the origin of this barrier to a very slow (t½ ∼4 min) trans-cis prolyl isomerization event involving changes in secondary structure. The less populated (10%) cis isomer is the binding-competent species, thus requiring the 90% of molecules in the trans configuration to isomerize before binding. The association rate for the cis isomer approaches 6 × 107 m−1 s−1, a ceiling for antigen-antibody interactions. Mutagenesis experiments showed that Pro-41 in E7Ep was required for both binding and isomerization. After a slow postbinding unimolecular rearrangement, a consolidated complex with KD = 1.2 × 10−7 m is reached. Our results suggest that presentation of this viral epitope by the antigen-presenting cells would have to be “locked” in the cis conformation, in opposition to the most populated trans isomer, in order to select the specific antibody clone that goes through affinity and kinetic maturation. PMID:23504368

  2. 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.

  3. 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.

  4. Universal Uncertainty Relations

    NASA Astrophysics Data System (ADS)

    Gour, Gilad

    2014-03-01

    Uncertainty relations are a distinctive characteristic of quantum theory that imposes intrinsic limitations on the precision with which physical properties can be simultaneously determined. The modern work on uncertainty relations employs entropic measures to quantify the lack of knowledge associated with measuring non-commuting observables. However, I will show here that there is no fundamental reason for using entropies as quantifiers; in fact, any functional relation that characterizes the uncertainty of the measurement outcomes can be used to define an uncertainty relation. Starting from a simple assumption that any measure of uncertainty is non-decreasing under mere relabeling of the measurement outcomes, I will show that Schur-concave functions are the most general uncertainty quantifiers. I will then introduce a novel fine-grained uncertainty relation written in terms of a majorization relation, which generates an infinite family of distinct scalar uncertainty relations via the application of arbitrary measures of uncertainty. This infinite family of uncertainty relations includes all the known entropic uncertainty relations, but is not limited to them. In this sense, the relation is universally valid and captures the essence of the uncertainty principle in quantum theory. This talk is based on a joint work with Shmuel Friedland and Vlad Gheorghiu. This research is supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada and by the Pacific Institute for Mathematical Sciences (PIMS).

  5. 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.

  6. Intrinsic Photoluminescence Emission from Subdomained Graphene Quantum Dots.

    PubMed

    Yoon, Hyewon; Chang, Yun Hee; Song, Sung Ho; Lee, Eui-Sup; Jin, Sung Hwan; Park, Chanae; Lee, Jinsup; Kim, Bo Hyun; Kang, Hee Jae; Kim, Yong-Hyun; Jeon, Seokwoo

    2016-07-01

    The photoluminescence (PL) origin of bright blue emission arising from intrinsic states in graphene quantum dots (GQDs) is investigated. The bright PL of intercalatively acquired GQDs is attributed to favorably formed subdomains composed of four to seven carbon hexagons. Random and harsh oxidation which hinders the energetically favorable formation of subdomains causes weak and redshifted PL. PMID:27153519

  7. 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…

  8. Associations of personality with intrinsic motivation in schizophrenia.

    PubMed

    Vohs, Jenifer L; Lysaker, Paul H; Nabors, Lori

    2013-06-30

    Motivation is often disturbed in patients with schizophrenia, but little is known about how it relates to personality. We examined intrinsic motivation (IM), two personality domains from the NEO Five-Factor Inventory, and symptoms in 58 male patients with schizophrenia spectrum disorders. Analyses revealed IM may be linked to Extraversion, Neuroticism, and negative symptoms. PMID:23566367

  9. 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. __________________________________________________

  10. 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. PMID:25823869

  11. TiO(2) nanotube arrays: intrinsic peroxidase mimetics.

    PubMed

    Zhang, Lingling; Han, Lei; Hu, Peng; Wang, Li; Dong, Shaojun

    2013-11-18

    TiO2 nanotube arrays (NTA), prepared by potentiostatic anodization, were discovered to possess an intrinsic peroxidase-like activity. The colorimetric and electrochemical assays both demonstrated their excellent catalytic activity towards H2O2 reduction. On this basis, a simple and inexpensive electrochemical biosensor for glucose detection was developed. PMID:24084751

  12. 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…

  13. Increasing Intrinsic Motivation to Learn in Organizational Behavior Classes

    ERIC Educational Resources Information Center

    McEvoy, Glenn M.

    2011-01-01

    This article describes my experiences redesigning a masters-level organizational behavior (OB) course. The course was delivered to two different audiences--MBA and MS-HR students--two different times. The redesign employed several unique features designed to increase and enhance student intrinsic interest in the subject matter. Two measures of…

  14. 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

  15. Visual representations are dominated by intrinsic fluctuations correlated between areas.

    PubMed

    Henriksson, Linda; Khaligh-Razavi, Seyed-Mahdi; Kay, Kendrick; Kriegeskorte, Nikolaus

    2015-07-01

    Intrinsic cortical dynamics are thought to underlie trial-to-trial variability of visually evoked responses in animal models. Understanding their function in the context of sensory processing and representation is a major current challenge. Here we report that intrinsic cortical dynamics strongly affect the representational geometry of a brain region, as reflected in response-pattern dissimilarities, and exaggerate the similarity of representations between brain regions. We characterized the representations in several human visual areas by representational dissimilarity matrices (RDMs) constructed from fMRI response-patterns for natural image stimuli. The RDMs of different visual areas were highly similar when the response-patterns were estimated on the basis of the same trials (sharing intrinsic cortical dynamics), and quite distinct when patterns were estimated on the basis of separate trials (sharing only the stimulus-driven component). We show that the greater similarity of the representational geometries can be explained by coherent fluctuations of regional-mean activation within visual cortex, reflecting intrinsic dynamics. Using separate trials to study stimulus-driven representations revealed clearer distinctions between the representational geometries: a Gabor wavelet pyramid model explained representational geometry in visual areas V1-3 and a categorical animate-inanimate model in the object-responsive lateral occipital cortex. PMID:25896934

  16. 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

  17. 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…

  18. 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…

  19. 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…

  20. 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...

  1. 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...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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...

  3. 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...

  4. Intrinsic frames of reference in haptic spatial learning.

    PubMed

    Yamamoto, Naohide; Philbeck, John W

    2013-11-01

    It has been proposed that spatial reference frames with which object locations are specified in memory are intrinsic to a to-be-remembered spatial layout (intrinsic reference theory). Although this theory has been supported by accumulating evidence, it has only been collected from paradigms in which the entire spatial layout was simultaneously visible to observers. The present study was designed to examine the generality of the theory by investigating whether the geometric structure of a spatial layout (bilateral symmetry) influences selection of spatial reference frames when object locations are sequentially learned through haptic exploration. In two experiments, participants learned the spatial layout solely by touch and performed judgments of relative direction among objects using their spatial memories. Results indicated that the geometric structure can provide a spatial cue for establishing reference frames as long as it is accentuated by explicit instructions (Experiment 1) or alignment with an egocentric orientation (Experiment 2). These results are entirely consistent with those from previous studies in which spatial information was encoded through simultaneous viewing of all object locations, suggesting that the intrinsic reference theory is not specific to a type of spatial memory acquired by the particular learning method but instead generalizes to spatial memories learned through a variety of encoding conditions. In particular, the present findings suggest that spatial memories that follow the intrinsic reference theory function equivalently regardless of the modality in which spatial information is encoded. PMID:24007919

  5. Children's Locus of Control and Intrinsically Motivated Reading.

    ERIC Educational Resources Information Center

    Whitney, Patricia

    A study investigated the relationship between locus of control and intrinsically motivated reading for children. The entire sixth grade, totalling 53 students, of a parochial school in San Francisco was administered the Children's Nowicki-Strickland Internal-External Control Scale. A free-choice paperback reading rack provided the measure for…

  6. 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.

  7. 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

  8. Attitudes toward Money, Intrinsic Job Satisfaction, and Voluntary Turnover.

    ERIC Educational Resources Information Center

    Tang, Thomas Li-Ping; Tang, Theresa Li-Na

    A study was conducted to determine whether employees' attitudes toward money (money ethic endorsement) moderates the relationships between intrinsic job satisfaction on the one hand and thoughts of withdrawal and voluntary turnover on the other. Data were collected from workers in the Department of Mental Health and Mental Retardation in a…

  9. Intrinsic Temporal Patterning in the Spontaneous Movement of Awake Neonates.

    ERIC Educational Resources Information Center

    Robertson, Steven S.

    1982-01-01

    The temporal organization of spontaneous movement in healthy, awake neonates was studied on the second or third day after birth. Movement was recorded using time lapse photography and quantified as a function of time. Evidence of intrinsic temporal organization among subjects was found. (MP)

  10. Isolating Intrinsic Processing Disorders from Second Language Acquisition.

    ERIC Educational Resources Information Center

    Lock, Robin H.; Layton, Carol A.

    2002-01-01

    Evaluation of the validity of the Learning Disabilities Diagnostic Inventory with limited-English-proficient (LEP) students in grades 2-7 found that nondisabled LEP students were over-identified as having intrinsic processing deficits. Examination of individual student protocols highlighted the need to train teacher-raters in language acquisition…

  11. Simple intrinsic defects in InAs : numerical predictions.

    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.

  12. 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…

  13. 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.

  14. 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…

  15. Visual representations are dominated by intrinsic fluctuations correlated between areas

    PubMed Central

    Henriksson, Linda; Khaligh-Razavi, Seyed-Mahdi; Kay, Kendrick; Kriegeskorte, Nikolaus

    2015-01-01

    Intrinsic cortical dynamics are thought to underlie trial-to-trial variability of visually evoked responses in animal models. Understanding their function in the context of sensory processing and representation is a major current challenge. Here we report that intrinsic cortical dynamics strongly affect the representational geometry of a brain region, as reflected in response-pattern dissimilarities, and exaggerate the similarity of representations between brain regions. We characterized the representations in several human visual areas by representational dissimilarity matrices (RDMs) constructed from fMRI response-patterns for natural image stimuli. The RDMs of different visual areas were highly similar when the response-patterns were estimated on the basis of the same trials (sharing intrinsic cortical dynamics), and quite distinct when patterns were estimated on the basis of separate trials (sharing only the stimulus-driven component). We show that the greater similarity of the representational geometries can be explained by coherent fluctuations of regional-mean activation within visual cortex, reflecting intrinsic dynamics. Using separate trials to study stimulus-driven representations revealed clearer distinctions between the representational geometries: a Gabor wavelet pyramid model explained representational geometry in visual areas V1–3 and a categorical animate–inanimate model in the object-responsive lateral occipital cortex. PMID:25896934

  16. Teacher and Student Intrinsic Motivation in Project-Based Learning

    ERIC Educational Resources Information Center

    Lam, Shui-fong; Cheng, Rebecca Wing-yi; Ma, William Y. K.

    2009-01-01

    In this study we examined the relationship between teacher and student intrinsic motivation in project-based learning. The participants were 126 Hong Kong secondary school teachers and their 631 students who completed evaluation questionnaires after a semester-long project-based learning program. Both teachers and students were asked to indicate…

  17. 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.

  18. 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…

  19. Extrinsic photoresponse enhancement under additional intrinsic photoexcitation in organic semiconductors

    NASA Astrophysics Data System (ADS)

    Kounavis, P.

    2016-06-01

    Dual light beam photoresponse experiments are employed to explore the photoresponse under simultaneous extrinsic and intrinsic photoexcitation of organic semiconductors. The photoresponse of a red modulated light extrinsic photoexcitation is found that can be significantly enhanced under an additional blue bias-light intrinsic photoexcitation in two terminal pentacene films on glass substrates. From the frequency resolved photoresponse, it is deduced that the phenomenon of photoresponse enhancement can be attributed to an increase in the extrinsic photogeneration rate of the red modulated light and/or an improvement of the drift velocity of carriers under an additional blue light intrinsic photoexcitation. The possible predominant extrinsic photogeneration mechanism, which can be compatible with the observed dependence of the photoresponse enhancement on the frequency and on the light intensities of the red and blue light excitation, is the singlet exciton dissociation through electron transfer to acceptor-like traps. Moreover, an improvement in the drift velocity of carriers traversing grain boundaries with potential energy barriers, which may be reduced by trapping of minority carriers created from the intrinsic photoexcitation, may partly contribute to the photoresponse enhancement.

  20. Distinct molecular signatures of mild extrinsic and intrinsic atopic dermatitis.

    PubMed

    Martel, Britta C; Litman, Thomas; Hald, Andreas; Norsgaard, Hanne; Lovato, Paola; Dyring-Andersen, Beatrice; Skov, Lone; Thestrup-Pedersen, Kristian; Skov, Søren; Skak, Kresten; Poulsen, Lars K

    2016-06-01

    Atopic dermatitis (AD) is a common inflammatory skin disease with underlying defects in epidermal function and immune responses. In this study, we used microarray analysis to investigate differences in gene expression in lesional skin from patients with mild extrinsic or intrinsic AD compared to skin from healthy controls and from lesional psoriasis skin. The primary aim was to identify differentially expressed genes involved in skin barrier formation and inflammation, and to compare our results with those reported for patients with moderate and severe AD. In contrast to severe AD, expression of the majority of genes associated with skin barrier formation was unchanged or upregulated in patients with mild AD compared to normal healthy skin. Among these, no significant differences in the expression of filaggrin (FLG) and loricrin at both mRNA and protein level were found in lesional skin from patients with mild AD, despite the presence of heterozygous FLG mutations in the majority of patients with mild extrinsic AD. Several inflammation-associated genes such as S100A9, MMP12, CXCL10 and CCL18 were highly expressed in lesional skin from patients with mild psoriasis and were also increased in patients with mild extrinsic and intrinsic AD similar to previous reports for severe AD. Interestingly, expression of genes involved in inflammatory responses in intrinsic AD resembled that of psoriasis more than that of extrinsic AD. Overall, differences in expression of inflammation-associated genes found among patients with mild intrinsic and extrinsic AD correlated with previous findings for patients with severe intrinsic and extrinsic AD. PMID:26841714

  1. 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

  2. Embedded intrinsic Fabry-Perot optical fiber sensors in cement concrete structures

    NASA Astrophysics Data System (ADS)

    Kim, Ki S.; Yoo, Jae-Wook; Kim, Seung Kwan; Kim, Byoung Yoon

    1996-05-01

    Intrinsic Fabry-Perot optical fiber sensors were embedded to the tensile side of the 20 cm by 20 cm by 150 cm cement concrete structures. The sensors were attached to the reinforcing steels and then, the cement concretes were applied. It took 30 days for curing the specimens. After that, the specimens were tested with 4-point bending method by a universal testing machine. Strains were measured and recorded by the strain gauges embedded near optical fiber sensors. Output data of fiber sensor showed good linearity to the strain data from the strain gauges up to 2000 microstrain. The optical fiber sensors showed good response after yielding of the structure while embedded metal film strain gauges did not show any response. We also investigated the behavior of the optical fiber sensor when the specimens were broken down. In conclusion, the optical fiber sensors can be used as elements of health monitoring systems for cement concrete infra-structures.

  3. 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.

  4. Local delivery methods of therapeutic agents in the treatment of diffuse intrinsic brainstem gliomas.

    PubMed

    Goodwin, C Rory; Xu, Risheng; Iyer, Rajiv; Sankey, Eric W; Liu, Ann; Abu-Bonsrah, Nancy; Sarabia-Estrada, Rachel; Frazier, James L; Sciubba, Daniel M; Jallo, George I

    2016-03-01

    Brainstem gliomas comprise 10-20% of all pediatric central nervous system (CNS) tumors and diffuse intrinsic pontine gliomas (DIPGs) account for the majority of these lesions. DIPG is a rapidly progressive disease with almost universally fatal outcomes and a median survival less than 12 months. Current standard-of-care treatment for DIPG includes radiation therapy, but its long-term survival effects are still under debate. Clinical trials investigating the efficacy of systemic administration of various therapeutic agents have been associated with disappointing outcomes. Recent efforts have focused on improvements in chemotherapeutic agents employed and in methods of localized and targeted drug delivery. This review provides an update on current preclinical and clinical studies investigating treatment options for brainstem gliomas. PMID:26849840

  5. 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…

  6. 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…

  7. Recapturing the Universal in the University

    ERIC Educational Resources Information Center

    Barnett, Ronald

    2005-01-01

    The idea of "the university" has stood for universal themes--of knowing, of truthfulness, of learning, of human development, and of critical reason. Through its affirming and sustaining of such themes, the university came itself to stand for universality in at least two senses: the university was neither partial (in its truth criteria) nor local…

  8. Open University

    ScienceCinema

    None

    2011-04-25

    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.

  9. 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.

  10. "A Real Rollercoaster of Confidence and Emotions": Learning to Be a University Student

    ERIC Educational Resources Information Center

    Christie, Hazel; Tett, Lyn; Cree, Vivienne E.; Hounsell, Jenny; McCune, Velda

    2008-01-01

    Accounts of emotion and affect have gained popularity in studies of learning. This article draws on qualitative research with a group of non-traditional students entering an elite university in the UK to illustrate how being and becoming a university student is an intrinsically emotional process. It argues that feelings of loss and dislocation are…

  11. Describing Sequence-Ensemble Relationships for Intrinsically Disordered Proteins

    PubMed Central

    Mao, Albert H.; Lyle, Nicholas; Pappu, Rohit V.

    2014-01-01

    Synopsis Intrinsically disordered proteins participate in important protein-protein and protein-nucleic acid interactions and control cellular phenotypes through their prominence as dynamic organizers of transcriptional, post-transcriptional, and signaling networks. These proteins challenge the tenets of the structure-function paradigm and their functional mechanisms remain a mystery given that they fail to fold autonomously into specific structures. Solving this mystery requires a first principles understanding of the quantitative relationships between information encoded in the sequences of disordered proteins and the ensemble of conformations they sample. Advances in quantifying sequence-ensemble relationships have been facilitated through a four-way synergy between bioinformatics, biophysical experiments, computer simulations, and polymer physics theories. Here, we review these advances and the resultant insights that allow us to develop a concise quantitative framework for describing sequence-ensemble relationships of intrinsically disordered proteins. PMID:23240611

  12. Intrinsic randomness as a measure of quantum coherence

    NASA Astrophysics Data System (ADS)

    Yuan, Xiao; Zhou, Hongyi; Cao, Zhu; Ma, Xiongfeng

    2015-08-01

    Based on the theory of quantum mechanics, intrinsic randomness in measurement distinguishes quantum effects from classical ones. From the perspective of states, this quantum feature can be summarized as coherence or superposition in a specific (classical) computational basis. Recently, by regarding coherence as a physical resource, Baumgratz et al. [Phys. Rev. Lett. 113, 140401 (2014), 10.1103/PhysRevLett.113.140401] presented a comprehensive framework for coherence measures. Here, we propose a quantum coherence measure essentially using the intrinsic randomness of measurement. The proposed coherence measure provides an answer to the open question in completing the resource theory of coherence. Meanwhile, we show that the coherence distillation process can be treated as quantum extraction, which can be regarded as an equivalent process of classical random number extraction. From this viewpoint, the proposed coherence measure also clarifies the operational aspect of quantum coherence. Finally, our results indicate a strong similarity between two types of quantumness—coherence and entanglement.

  13. Spin dependence of intrinsic and transition quadrupole moments

    SciTech Connect

    Jolos, R.V.; Brentano, P. von; Dewald, A.; Pietralla, N.

    2005-08-01

    The relation connecting an angular momentum dependence of the {gamma}-transition energies with the reduced transition probabilities B[E2;(I+2){sub gr}{yields}I{sub gr}] in the ground-state rotational band is derived based on the Bohr Hamiltonian. The relation is applicable to both {beta}-rigid and {beta}-soft both being {gamma}-rigid nuclei. Based on this result the approximate expression is obtained for the intrinsic quadrupole moment and, therefore, for the spectroscopic quadrupole moment in terms of the reduced E2 transition probabilities. It is shown that an angular momentum dependence of the intrinsic quadrupole moment can be well approximated by a linear function of I. The results obtained are direct consequences of the Bohr Hamiltonian with the Davidson potential.

  14. 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

  15. 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.

  16. Intrinsic trapping sites in rare-earth and yttrium oxyorthosilicates

    SciTech Connect

    Cooke, D.W.; Bennett, B.L.; Muenchausen, R.E.; McClellan, K.J.; Roper, J.M.; Whittaker, M.T.

    1999-11-01

    Similarity among the thermally stimulated luminescence glow curves of undoped Lu{sub 2}SiO{sub 5} and Ce{sup 3+}-doped oxyorthosilicates possessing the monoclinic C2/c structure strongly suggests the luminescence traps are intrinsic in origin. They are most likely associated with the configuration of oxygen ions in the vicinity of not only the Ce{sup 3+} ion, as suggested in previous work, but also the host lanthanide ion. The optical absorption spectrum of pristine Lu{sub 2}SiO{sub 5} shows the presence of intrinsic absorption centers that are enhanced upon x irradiation as seen in other oxides containing oxygen related point defects. {copyright} {ital 1999 American Institute of Physics.}

  17. 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.

  18. 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

  19. Intrinsic Emittance Reduction of an Electron Beam from Metal Photocathodes

    SciTech Connect

    Hauri, C. P.; Ganter, R.; Le Pimpec, F.; Trisorio, A.; Ruchert, C.; Braun, H. H.

    2010-06-11

    Electron beams in modern linear accelerators are now becoming limited in brightness by the intrinsic emittance of the photocathode electron source. Therefore it becomes important for large scale facilities such as free electron lasers to reduce this fundamental limit. In this Letter we present measurements of the intrinsic emittance for different laser wavelength (from 261 to 282 nm) and for different photocathode materials such as Mo, Nb, Al, Cu. Values as low as 0.41{+-}0.03 mm{center_dot}mrad/mm laser spot size (rms) were measured for a copper photocathode illuminated with a 282 nm laser wavelength. The key element for emittance reduction is a uv laser system which allows adjustment of the laser photon energy to match the effective work function of the cathode material and to emit photoelectrons with a lower initial kinetic energy. The quantum efficiency over the explored wavelength range varies by less than a factor of 3.

  20. Amplification of intrinsic fluctuations by the Lorenz equations

    NASA Astrophysics Data System (ADS)

    Fox, Ronald F.; Elston, T. C.

    1993-07-01

    Macroscopic systems (e.g., hydrodynamics, chemical reactions, electrical circuits, etc.) manifest intrinsic fluctuations of molecular and thermal origin. When the macroscopic dynamics is deterministically chaotic, the intrinsic fluctuations may become amplified by several orders of magnitude. Numerical studies of this phenomenon are presented in detail for the Lorenz model. Amplification to macroscopic scales is exhibited, and quantitative methods (binning and a difference-norm) are presented for measuring macroscopically subliminal amplification effects. In order to test the quality of the numerical results, noise induced chaos is studied around a deterministically nonchaotic state, where the scaling law relating the Lyapunov exponent to noise strength obtained for maps is confirmed for the Lorenz model, a system of ordinary differential equations.

  1. 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.

  2. A facile route to recover intrinsic graphene over large scale.

    PubMed

    Shin, Dong-Wook; Lee, Hyun Myoung; Yu, Seong Man; Lim, Kwang-Soo; Jung, Jae Hoon; Kim, Min-Kyu; Kim, Sang-Woo; Han, Jae-Hee; Ruoff, Rodney S; Yoo, Ji-Beom

    2012-09-25

    The intrinsic properties of initially p-type doped graphene (grown by chemical vapor deposition (CVD)) can be recovered by buffered oxide etch (BOE) treatment, and the dominant factor governing p-type doping is identified as the H(2)O/O(2) redox system. Semi-ionic C-F bonding prevents the reaction between the products of the H(2)O/O(2) redox system and graphene. BOE-treated graphene field effect transistors (FETs) subsequently exposed to air, became p-type doped due to recovery of the H(2)O/O(2) redox system. In comparison, poly(methyl methacrylate) (PMMA)-coated graphene FETs had improved stability for maintaining the intrinsic graphene electronic properties. PMID:22928753

  3. Phosphorylation of Intrinsically Disordered Regions in Remorin Proteins

    PubMed Central

    Marín, Macarena; Ott, Thomas

    2012-01-01

    Plant-specific remorin proteins reside in subdomains of plasma membranes, originally termed membrane rafts. They probably facilitate cellular signal transduction by direct interaction with signaling proteins such as receptor-like kinases and may dynamically modulate their lateral segregation within plasma membranes. Recent evidence suggests such functions of remorins during plant–microbe interactions and innate immune responses, where differential phosphorylation of some of these proteins has been described to be dependent on the perception of the microbe-associated molecular pattern (MAMP) flg22 and the presence of the NBS–LRR resistance protein RPM1. A number of specifically phosphorylated residues in their highly variable and intrinsically disordered N-terminal regions have been identified. Sequence diversity of these evolutionary distinct domains suggests that remorins may serve a wide range of biological functions. Here, we describe patterns and features of intrinsic disorder in remorin protein and discuss possible functional implications of phosphorylation within these rapidly evolving domains. PMID:22639670

  4. 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

  5. Transport through graphenelike flakes with intrinsic spin-orbit interactions

    NASA Astrophysics Data System (ADS)

    Weymann, I.; Barnaś, J.; Krompiewski, S.

    2015-07-01

    It was shown recently [J. L. Lado and J. Fernández-Rossier, Phys. Rev. Lett. 113, 027203 (2014), 10.1103/PhysRevLett.113.027203] that edge magnetic moments in graphene-like nanoribbons are strongly influenced by the intrinsic spin-orbit interaction. Due to this interaction an anisotropy comes about which makes the in-plane arrangement of magnetic moments energetically more favorable than that corresponding to the out-of-plane configuration. In this paper we raise both the edge magnetism problem and the differential conductance and shot noise Fano factor issues, in the context of finite-size flakes within the Coulomb blockade (CB) transport regime. Our findings elucidate the following problems: (i) modification of CB diamonds by the appearance of in-plane magnetic moments and (ii) modification of CB diamonds by the intrinsic spin-orbit interaction.

  6. 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

  7. Electronic structure of intrinsic defects in crystalline germanium telluride.

    SciTech Connect

    Thompson, Aidan Patrick; Pineda, Andrew C.; Umrigar, Cyrus J.; Hjalmarson, Harold Paul; Schultz, Peter Andrew; Edwards, Arthur H.; Martin, Marcus Gary

    2005-05-01

    Germanium telluride undergoes rapid transition between polycrystalline and amorphous states under either optical or electrical excitation. While the crystalline phases are predicted to be semiconductors, polycrystalline germanium telluride always exhibits p-type metallic conductivity. We present a study of the electronic structure and formation energies of the vacancy and antisite defects in both known crystalline phases. We show that these intrinsic defects determine the nature of free-carrier transport in crystalline germanium telluride. Germanium vacancies require roughly one-third the energy of the other three defects to form, making this by far the most favorable intrinsic defect. While the tellurium antisite and vacancy induce gap states, the germanium counterparts do not. A simple counting argument, reinforced by integration over the density of states, predicts that the germanium vacancy leads to empty states at the top of the valence band, thus giving a complete explanation of the observed p-type metallic conduction.

  8. Circumstellar grains and the intrinsic polarization of starlight

    NASA Technical Reports Server (NTRS)

    Forrest, W. J.; Gillett, F. C.; Stein, W. A.

    1975-01-01

    Twenty-five long-period variable stars exhibiting intrinsic variable polarization have been monitored over the range 3.5-11 microns for several cycles. No conclusive evidence for gross changes in amount of circumstellar grains has been found. Thus circumstellar infrared emission is attributed to the total abundance of grains surrounding the star, which does not change by a large amount with time, while intrinsic polarization is attributed to more localized scattering and absorption effects. Spectrophotometry with resolution of about 0.015 over the 8-14 microns wavelength range of several stars with different chemical compositions indicates excess emission characteristic of 3 types of grains: (1) 'blackbody' grains, (2) silicate grains, and (3) silicon carbide grains.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Intrinsic Coupling Modes in Source-Reconstructed Electroencephalography

    PubMed Central

    Breakspear, Michael; Britz, Juliane; Boonstra, Tjeerd W.

    2014-01-01

    Abstract Intrinsic coupling of neuronal assemblies constitutes a key feature of ongoing brain activity, yielding the rich spatiotemporal patterns observed in neuroimaging data and putatively supporting cognitive processes. Intrinsic coupling has been investigated in electrophysiological recordings using two types of functional connectivity measures: amplitude and phase coupling. These two coupling modes differ in their likely causes and functions, and have been proposed to provide complementary insights into intrinsic neuronal interactions. Here, we investigate the relationship between amplitude and phase coupling in source-reconstructed electroencephalography (EEG). Volume conduction is a key obstacle for connectivity analysis in EEG—we therefore also test the envelope correlation of orthogonalized signals and the phase lag index. Functional connectivity between six seed source regions (bilateral visual, sensorimotor, and auditory cortices) and all other cortical voxels was computed. For all four measures, coupling between homologous sensory areas in both hemispheres was significantly higher than with other voxels at the same physical distance. The frequency of significant coupling differed between sensory areas: 10 Hz for visual, 30 Hz for auditory, and 40 Hz for sensorimotor cortices. By contrasting envelope correlations and phase locking values, we observed two distinct clusters of voxels showing a different relationship between amplitude and phase coupling. Large clusters contiguous to the seed regions showed an identity (1:1) relationship between amplitude and phase coupling, whereas a cluster located around the contralateral homologous regions showed higher phase than amplitude coupling. These results show a relationship between intrinsic coupling modes that is distinct from the effect of volume conduction. PMID:25230358

  17. Environmental applications for an intrinsic germanium well detector

    SciTech Connect

    Stegnar, P.; Eldridge, J.S.; Teasley, N.A.; Oakes, T.W.

    1983-01-01

    The overall performance of an intrinsic germanium well detector for /sup 125/I measurements was investigated in a program of environmental surveillance. Concentrations of /sup 125/I and /sup 131/I were determined in thyroids of road-killed deer showing the highest activities of /sup 125/I in the animals from the near vicinity of Oak Ridge National Laboratory. This demonstrates the utility of road-killed deer as a bioindicator for radioiodine around nuclear facilities. 6 refs., 2 figs., 3 tabs.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. Intrinsic shapes of elliptical galaxy: NGC 1052 using modified prior

    NASA Astrophysics Data System (ADS)

    Kumar Singh, Arun; Chakraborty, D. K.

    Determination of intrinsic shapes of the individual elliptical galaxies using photometry is an important problem because the number of galaxies with good photometry is many more than those with good kinematics. We determine the intrinsic shapes of the light distribution of elliptical galaxies by combining the profiles of photometric data from the literature with triaxial models. We use ensembles of models so that the shape estimates are largely model independent. We follow the methodology as described in Statler (1994) which is modified to suit our requirements. We find that short to long axial ratios at very small radii and at very large radii, and the absolute value of the triaxiality difference are the best constrained shape parameters. Using a flat prior, the shapes of elliptical galaxies are reported by Chakraborty et al (2008) and Singh & Chakraborty (2009). The flat prior of 20 galaxies are superimposed over EAC-Ph other to obtain the distribution. This distribution is regarded as a prior (a modified prior) and shapes of 20 galaxies are again recalculated by using such modified prior. We determine the intrinsic shapes of the elliptical galaxy NGC 1052 using modified prior should be more reliable. These results are compared with the previous estimates which are determined by using flat prior. The plot shows the intrinsic shapes of the NGC 1052 as a function of (q0,q∞) for two dimensional shapes and (q0,q∞, |Td|) for three dimensional shapes, where q0 and q∞(=q) are the short to long axial ratios at small and at large radii and |Td| is the absolute values of the triaxiality difference, defined as |Td|= |T∞ - T0|. The probability is shown in the dark gray region: darker is the region higher is the probability. We find that the galaxy NGC 1052 is flatter inside and flatter outside.

  3. 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.

  4. 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.

  5. 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.

  6. An intrinsic mechanism of secreted protein aging and turnover

    PubMed Central

    Yang, Won Ho; Aziz, Peter V.; Heithoff, Douglas M.; Mahan, Michael J.; Smith, Jeffrey W.; Marth, Jamey D.

    2015-01-01

    The composition and functions of the secreted proteome are controlled by the life spans of different proteins. However, unlike intracellular protein fate, intrinsic factors determining secreted protein aging and turnover have not been identified and characterized. Almost all secreted proteins are posttranslationally modified with the covalent attachment of N-glycans. We have discovered an intrinsic mechanism of secreted protein aging and turnover linked to the stepwise elimination of saccharides attached to the termini of N-glycans. Endogenous glycosidases, including neuraminidase 1 (Neu1), neuraminidase 3 (Neu3), beta-galactosidase 1 (Glb1), and hexosaminidase B (HexB), possess hydrolytic activities that temporally remodel N-glycan structures, progressively exposing different saccharides with increased protein age. Subsequently, endocytic lectins with distinct binding specificities, including the Ashwell–Morell receptor, integrin αM, and macrophage mannose receptor, are engaged in N-glycan ligand recognition and the turnover of secreted proteins. Glycosidase inhibition and lectin deficiencies increased protein life spans and abundance, and the basal rate of N-glycan remodeling varied among distinct proteins, accounting for differences in their life spans. This intrinsic multifactorial mechanism of secreted protein aging and turnover contributes to health and the outcomes of disease. PMID:26489654

  7. 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

  8. 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.

  9. Intrinsic low-frequency variability of the Gulf Stream

    NASA Astrophysics Data System (ADS)

    Quattrocchi, G.; Pierini, S.; Dijkstra, H. A.

    2012-03-01

    In this paper a process study aimed at analyzing the low-frequency variability of intrinsically oceanic origin of the Gulf Stream (GS) and GS extension (GSE) is presented. An eddy-permitting reduced-gravity nonlinear shallow water model is implemented in an idealized North Atlantic Ocean, with schematic boundaries including the essential geometric features of the coastline and a realistic zonal basin width at all latitudes. The forcing is provided by a time-independent climatological surface wind stress obtained from 41 years of monthly ECMWF fields. The model response yields strong intrinsic low-frequency fluctuations on the interannual to decadal time scales. The modelled time-averaged GS/GSE flows are found to exhibit several features that can also be deduced from satellite altimeter data, such as the Florida Current seaward deflection, the GS separation at Cape Hatteras, and the overall structure of the GSE. The intrinsic low-frequency variability yields two preferred states of the GSE differing in latitudinal location that also have their counterpart in the altimeter data. A preliminary analysis of the variability in terms of dynamical systems theory is carried out by using the lateral eddy viscosity as the control parameter. A complex transition sequence from a steady state to irregular low-frequency variability emerges, in which Hopf and global bifurcations can be identified.

  10. Intrinsic photocatalytic assessment of reactively sputtered TiO₂ films.

    PubMed

    Rafieian, Damon; Driessen, Rick T; Ogieglo, Wojciech; Lammertink, Rob G H

    2015-04-29

    Thin TiO2 films were prepared by DC magnetron reactive sputtering at different oxygen partial pressures. Depending on the oxygen partial pressure during sputtering, a transition from metallic Ti to TiO2 was identified by spectroscopic ellipsometry. The crystalline nature of the film developed during a subsequent annealing step, resulting in thin anatase TiO2 layers, displaying photocatalytic activity. The intrinsic photocatalytic activity of the catalysts was evaluated for the degradation of methylene blue (MB) using a microfluidic reactor. A numerical model was employed to extract the intrinsic reaction rate constants. High conversion rates (90% degradation within 20 s residence time) were observed within these microreactors because of the efficient mass transport and light distribution. To evaluate the intrinsic reaction kinetics, we argue that mass transport has to be accounted for. The obtained surface reaction rate constants demonstrate very high reactivity for the sputtered TiO2 films. Only for the thinnest film, 9 nm, slightly lower kinetics were observed. PMID:25844637

  11. 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.

  12. 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. PMID:23602010

  13. 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.

  14. Intrinsic Functional Relations Between Human Cerebral Cortex and Thalamus

    PubMed Central

    Zhang, Dongyang; Snyder, Abraham Z.; Fox, Michael D.; Sansbury, Mark W.; Shimony, Joshua S.; Raichle, Marcus E.

    2008-01-01

    The brain is active even in the absence of explicit stimuli or overt responses. This activity is highly correlated within specific networks of the cerebral cortex when assessed with resting-state functional magnetic resonance imaging (fMRI) blood oxygen level–dependent (BOLD) imaging. The role of the thalamus in this intrinsic activity is unknown despite its critical role in the function of the cerebral cortex. Here we mapped correlations in resting-state activity between the human thalamus and the cerebral cortex in adult humans using fMRI BOLD imaging. Based on this functional measure of intrinsic brain activity we partitioned the thalamus into nuclear groups that correspond well with postmortem human histology and connectional anatomy inferred from nonhuman primates. This structure/function correspondence in resting-state activity was strongest between each cerebral hemisphere and its ipsilateral thalamus. However, each hemisphere was also strongly correlated with the contralateral thalamus, a pattern that is not attributable to known thalamocortical monosynaptic connections. These results extend our understanding of the intrinsic network organization of the human brain to the thalamus and highlight the potential of resting-state fMRI BOLD imaging to elucidate thalamocortical relationships. PMID:18701759

  15. 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

  16. Context-dependent resistance to proteolysis of intrinsically disordered proteins

    PubMed Central

    Suskiewicz, Marcin J; Sussman, Joel L; Silman, Israel; Shaul, Yosef

    2011-01-01

    Intrinsically disordered proteins (IDPs), also known as intrinsically unstructured proteins (IUPs), lack a well-defined 3D structure in vitro and, in some cases, also in vivo. Here, we discuss the question of proteolytic sensitivity of IDPs, with a view to better explaining their in vivo characteristics. After an initial assessment of the status of IDPs in vivo, we briefly survey the intracellular proteolytic systems. Subsequently, we discuss the evidence for IDPs being inherently sensitive to proteolysis. Such sensitivity would not, however, result in enhanced degradation if the protease-sensitive sites were sequestered. Accordingly, IDP access to and degradation by the proteasome, the major proteolytic complex within eukaryotic cells, are discussed in detail. The emerging picture appears to be that IDPs are inherently sensitive to proteasomal degradation along the lines of the “degradation by default” model. However, available data sets of intracellular protein half-lives suggest that intrinsic disorder does not imply a significantly shorter half-life. We assess the power of available systemic half-life measurements, but also discuss possible mechanisms that could protect IDPs from intracellular degradation. Finally, we discuss the relevance of the proteolytic sensitivity of IDPs to their function and evolution. PMID:21574196

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. [Phototransduction mediated by melanopsin in intrinsically photosensitive retinal ganglion cells].

    PubMed

    Domínguez-Solís, Carlos Augusto; Pérez-León, Jorge Alberto

    2015-01-01

    Melanopsin is the most recent photopigment described. As all the other opsins, it attaches in the retina as chromophore. Its amino acid sequence resembles more invertebrate opsins than those of vertebrates. The signal transduction pathway of opsins in vertebrates is based on the coupling to the G protein transducin, triggering a signaling cascade that results in the hyperpolarization of the plasma membrane. On the contrary, the photoreceptors of invertebrates activate the Gq protein pathway, which leads to depolarizing responses. Phototransduction mediated by melanopsin leads to the depolarization of those cells where it is expressed, the intrinsically photosensitive retinal ganglion cells; the cellular messengers and the ion channel type(s) responsible for the cells´ response is still unclear. Studies to elucidate the signaling cascade of melanopsin in heterologous expression systems, in retina and isolated/cultured intrinsically photosensitive retinal ganglion cells, have provided evidence for the involvement of protein Gq and phospholipase C together with the likely participation of an ion channel member of the transient receptor potential-canonical family, a transduction pathway similar to invertebrate photopigments, particularly Drosophila melanogaster. The intrinsically photosensitive retinal ganglion cells are the sole source of retinal inferences to the suprachiasmatic nucleus; thus, clarifying completely the melanopsin signaling pathway will impact the chronobiology field, including the clinical aspects. PMID:26581535

  3. Comparing Intrinsic Connectivity Models for the Primary Auditory Cortices

    NASA Astrophysics Data System (ADS)

    Hamid, Khairiah Abdul; Yusoff, Ahmad Nazlim; Mohamad, Mazlyfarina; Hamid, Aini Ismafairus Abd; Manan, Hanani Abd

    2010-07-01

    This fMRI study is about modeling the intrinsic connectivity between Heschl' gyrus (HG) and superior temporal gyrus (STG) in human primary auditory cortices. Ten healthy male subjects participated and required to listen to white noise stimulus during the fMRI scans. Two intrinsic connectivity models comprising bilateral HG and STG were constructed using statistical parametric mapping (SPM) and dynamic causal modeling (DCM). Group Bayes factor (GBF), positive evidence ratio (PER) and Bayesian model selection (BMS) for group studies were used in model comparison. Group results indicated significant bilateral asymmetrical activation (puncorr < 0.001) in HG and STG. Comparison results showed strong evidence of Model 2 as the preferred model (STG as the input center) with GBF value of 5.77 × 1073 The model is preferred by 6 out of 10 subjects. The results were supported by BMS results for group studies. One-sample t-test on connection values obtained from Model 2 indicates unidirectional parallel connections from STG to bilateral HG (p<0.05). Model 2 was determined to be the most probable intrinsic connectivity model between bilateral HG and STG when listening to white noise.

  4. Intrinsic network connectivity reflects consistency of synesthetic experiences.

    PubMed

    Dovern, Anna; Fink, Gereon R; Fromme, A Christina B; Wohlschläger, Afra M; Weiss, Peter H; Riedl, Valentin

    2012-05-30

    Studying cognitive processes underlying synesthesia, a condition in which stimulation of one sensory modality automatically leads to abnormal additional sensory perception, allows insights into the neural mechanisms of normal and abnormal cross-modal sensory processing. Consistent with the notion that synesthesia results from hyperconnectivity, functional connectivity analysis (adopting independent component analysis and seed-based correlation analysis) of resting-state functional magnetic resonance imaging data of 12 grapheme-color synesthetes and 12 nonsynesthetic control subjects revealed, in addition to increased intranetwork connectivity, both a global and a specific (medial and lateral visual networks to a right frontoparietal network) increase of intrinsic internetwork connectivity in grapheme-color synesthesia. Moreover, this increased intrinsic network connectivity reflected the strength of synesthetic experiences. These findings constitute the first direct evidence of increased functional network connectivity in synesthesia. In addition to this significant contribution to the understanding of the neural mechanisms of synesthesia, our results have important general implications. In combination with data derived from clinical populations, our data strongly suggest that altered differences in intrinsic network connectivity are directly related to the phenomenology of human experiences. PMID:22649240

  5. 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.

  6. The implication of SUMO in intrinsic and innate immunity.

    PubMed

    Hannoun, Zara; Maarifi, Ghizlane; Chelbi-Alix, Mounira K

    2016-06-01

    Since its discovery, SUMOylation has emerged as a key post-translational modification involved in the regulation of host-virus interactions. SUMOylation has been associated with the replication of a large number of viruses, either through the direct modification of viral proteins or through the modulation of cellular proteins implicated in antiviral defense. SUMO can affect protein function via covalent or non-covalent binding. There is growing evidence that SUMO regulates several host proteins involved in intrinsic and innate immunity, thereby contributing to the process governing interferon production during viral infection; as well as the interferon-activated Jak/STAT pathway. Unlike the interferon-mediated innate immune response, intrinsic antiviral resistance is mediated by constitutively expressed antiviral proteins (defined as restriction factors), which confer direct viral resistance through a variety of mechanisms. The aim of this review is to evaluate the role of SUMO in intrinsic and innate immunity; highlighting the involvement of the TRIM family proteins, with a specific focus on the mechanism through which SUMO affects i- interferon production upon viral infection, ii-interferon Jak/STAT signaling and biological responses, iii-the relationship between restriction factors and RNA viruses. PMID:27157810

  7. Iron-59 absorption from soy hulls: intrinsic vs extrinsic labeling

    SciTech Connect

    Lykken, G.I.; Mahalko, J.R.; Nielsen, E.J.; Dintzis, F.R.

    1986-03-05

    As part of an evaluation of the validity of the extrinsic labeling technique for measuring iron absorption, absorption from soy hulls extrinsically labeled (/sup 59/Fe added to bread dough) was compared with that from soy hulls intrinsically labeled (/sup 59/Fe incorporated into the soy plant during growth). Century soybeans were grown in a greenhouse. After pods had formed and were filling, each plant was stem injected twice, at 3 day intervals, with 22 ..mu..Ci /sup 59/Fe as FeCl/sub 2/ in 25 ..mu..l of 0.5 M HCl solution. After the plants had senesced, the soybeans were harvested, dried, shelled and the hulls removed. Standard meals containing 3.5 mg Fe/meal and up to 0.06 ..mu..Ci /sup 59/Fe in a soy hull bun were fed on 2 consecutive days to free-living volunteers in a crossover design. Absorption of /sup 59/Fe was greater from intrinsically labeled soy hulls than from extrinsically labeled soy hulls, 20 +/- 20% vs 15 +/- 11% (n=14, p > 0.05 by paired t-test). Apparent absorption ranged from 1.3% to 77% from intrinsically labeled soy hulls and .5% to 29% from extrinsically labeled soy hulls with the highest absorption occurring in persons with low serum ferritin (S.F. < 8 ng/ml). These findings provide additional evidence that the extrinsic labeling method is a valid measure of iron bioavailability to humans.

  8. Miniaturized INtrinsic DISsolution Screening (MINDISS) assay for preformulation.

    PubMed

    Alsenz, Jochem; Haenel, Elisabeth; Anedda, Aline; Du Castel, Pauline; Cirelli, Giorgio

    2016-05-25

    This study describes a novel Miniaturized INtrinsic DISsolution Screening (MINDISS) assay for measuring disk intrinsic dissolution rates (DIDR). In MINDISS, compacted mini disks of drugs (2-5mg/disk) are prepared in custom made holders with a surface area of 3mm(2). Disks are immersed, pellet side down, into 0.35ml of appropriate dissolution media per well in 96-well microtiter plates, media are stirred and disk-holders are transferred to new wells after defined periods of time. After filtration, drug concentration in dissolution media is quantified by Ultra Performance Liquid Chromatography (UPLC) and solid state property of the disk is characterized by Raman spectroscopy. MINDISS was identified as an easy-to-use tool for rapid, parallel determination of DIDR of compounds that requires only small amounts of compound and of dissolution medium. Results obtained with marketed drugs in MINDISS correlate well with large scale DIDR methods and indicate that MINDISS can be used for (1) rank-ordering of compounds by intrinsic dissolution in late phase discovery and early development, (2) comparison of polymorphic forms and salts, (3) screening and selection of appropriate dissolution media, and (4) characterization of the intestinal release behavior of compounds along the gastro intestinal tract by changing biorelevant media during experiments. PMID:26360839

  9. The multifaceted roles of intrinsic disorder in protein complexes.

    PubMed

    Uversky, Vladimir N

    2015-09-14

    Intrinsically disordered proteins (IDPs) and intrinsically disordered protein regions (IDPRs) are important constituents of many protein complexes, playing various structural, functional, and regulatory roles. In such disorder-based protein complexes, functional disorder is used both internally (for assembly, movement, and functional regulation of the different parts of a given complex) and externally (for interactions of a complex with its external regulators). In complex assembly, IDPs/IDPRs serve as the molecular glue that cements complexes or as highly flexible scaffolds. Disorder defines the order of complex assembly and the ability of a protein to be involved in polyvalent interactions. It is at the heart of various binding mechanisms and interaction modes ascribed to IDPs. Disorder in protein complexes is related to multifarious applications of induced folding and induced functional unfolding, or defines the entropic chain activities, such as stochastic machines and binding rheostats. This review opens a FEBS Letters Special Issue on Dynamics, Flexibility, and Intrinsic Disorder in protein assemblies and represents a brief overview of intricate roles played by IDPs and IDPRs in various aspects of protein complexes. PMID:26073257

  10. 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.

  11. Improvements in Intrinsic Feature Pose Measurement for Awake Animal Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Lee, Seung Joon; Weisenberger, A G; McKisson, J; Smith, M F; Stolin, Alexander

    2010-01-01

    Development has continued with intrinsic feature optical motion tracking for awake animal imaging to measure 3D position and orientation (pose) for motion compensated reconstruction. Prior imaging results have been directed towards head motion measurement for SPECT brain studies in awake unrestrained mice. This work improves on those results in extracting and tracking intrinsic features from multiple camera images and computing pose changes from the tracked features over time. Previously, most motion tracking for 3D imaging has been limited to measuring extrinsic features such as retro-reflective markers applied to an animal s head. While this approach has been proven to be accurate, the use of external markers is undesirable for several reasons. The intrinsic feature approach has been further developed from previous work to provide full pose measurements for a live mouse scan. Surface feature extraction, matching, and pose change calculation with point tracking and accuracy results are described. Experimental pose calculation and 3D reconstruction results from live images are presented.

  12. Effects of q-profile structures on intrinsic torque reversals

    NASA Astrophysics Data System (ADS)

    Lu, Z. X.; Wang, W. X.; Diamond, P. H.; Tynan, G.; Ethier, S.; Chen, J.; Gao, C.; Rice, J. E.

    2015-09-01

    Changes in rotation have been observed in LHCD experiments. From these observations, reversals in intrinsic torque have been inferred. This paper identifies the mechanism for intrinsic torque reversal linked to magnetic shear (\\hat{s} ). Gyrokinetic simulations demonstrate that as compared to the normal \\hat{s} case, the intrinsic torque reverses, for \\hat{s}<{{\\hat{s}}\\text{crit}} . Analysis shows that the reversal occurs due to the dominance of the symmetry breaking mechanism in residual stress due to the synergy of toroidal coupling and the intensity gradient. This mechanism is a consequence of ballooning structure at weak \\hat{s} . Gyrokinetic simulation gives {{\\hat{s}}\\text{crit}}≈ 0.3 for trapped electron modes (TEM) and {{\\hat{s}}\\text{crit}}≈ 1.1 for ion temperature gradient (ITG) modes. The value of {{\\hat{s}}\\text{crit}} is consistent with results from the Alcator C-Mod LHCD experiments, for which \\hat{s}>0 in the whole plasma column and \\hat{s}\\text{crit}\\text{exp}≈ 0.2∼ 0.3 (Rice et al Phys. Rev. Lett. 111 125003).

  13. Improvements in intrinsic feature pose measurement for awake animal imaging

    SciTech Connect

    J.S. Goddard, J.S. Baba, S.J. Lee, A.G. Weisenberger, A. Stolin, J. McKisson, M.F. Smith

    2011-06-01

    Development has continued with intrinsic feature optical motion tracking for awake animal imaging to measure 3D position and orientation (pose) for motion compensated reconstruction. Prior imaging results have been directed towards head motion measurement for SPECT brain studies in awake unrestrained mice. This work improves on those results in extracting and tracking intrinsic features from multiple camera images and computing pose changes from the tracked features over time. Previously, most motion tracking for 3D imaging has been limited to measuring extrinsic features such as retro-reflective markers applied to an animal's head. While this approach has been proven to be accurate, the use of external markers is undesirable for several reasons. The intrinsic feature approach has been further developed from previous work to provide full pose measurements for a live mouse scan. Surface feature extraction, matching, and pose change calculation with point tracking and accuracy results are described. Experimental pose calculation and 3D reconstruction results from live images are presented.

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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…

  1. A Longitudinal Study of Academic Intrinsic Motivation in Intellectually Gifted Children: Childhood through Early Adolescence.

    ERIC Educational Resources Information Center

    Gottfried, Adele Eskeles; Gottfried, Allen W.

    1996-01-01

    Intellectually gifted children (N=20) and a comparison group (N=79) were administered the Children's Academic Intrinsic Motivation Inventory at ages 9, 10, and 13. At all three ages, the gifted children had significantly higher academic intrinsic motivation across all subject areas and in school in general. Assessment of intrinsic motivation is…

  2. 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…

  3. Assessing Individual-Level Factors Supporting Student Intrinsic Motivation in Online Discussions: A Qualitative Study

    ERIC Educational Resources Information Center

    Shroff, Ronnie H.; Vogel, Douglas R.; Coombes, John

    2008-01-01

    Research has established that intrinsic motivation has a positive effect on learning and academic achievement. However, little is known about the impact of different technology-supported learning activities on student intrinsic motivation or whether such learning activities significantly enhance student intrinsic motivation compared to traditional…

  4. 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.

  5. Functional correlations of respiratory syncytial virus proteins to intrinsic disorder.

    PubMed

    Whelan, Jillian N; Reddy, Krishna D; Uversky, Vladimir N; Teng, Michael N

    2016-04-26

    Protein intrinsic disorder is an important characteristic demonstrated by the absence of higher order structure, and is commonly detected in multifunctional proteins encoded by RNA viruses. Intrinsically disordered regions (IDRs) of proteins exhibit high flexibility and solvent accessibility, which permit several distinct protein functions, including but not limited to binding of multiple partners and accessibility for post-translational modifications. IDR-containing viral proteins can therefore execute various functional roles to enable productive viral replication. Respiratory syncytial virus (RSV) is a globally circulating, non-segmented, negative sense (NNS) RNA virus that causes severe lower respiratory infections. In this study, we performed a comprehensive evaluation of predicted intrinsic disorder of the RSV proteome to better understand the functional role of RSV protein IDRs. We included 27 RSV strains to sample major RSV subtypes and genotypes, as well as geographic and temporal isolate differences. Several types of disorder predictions were applied to the RSV proteome, including per-residue (PONDR®-FIT and PONDR® VL-XT), binary (CH, CDF, CH-CDF), and disorder-based interactions (ANCHOR and MoRFpred). We classified RSV IDRs by size, frequency and function. Finally, we determined the functional implications of RSV IDRs by mapping predicted IDRs to known functional domains of each protein. Identification of RSV IDRs within functional domains improves our understanding of RSV pathogenesis in addition to providing potential therapeutic targets. Furthermore, this approach can be applied to other NNS viruses that encode essential multifunctional proteins for the elucidation of viral protein regions that can be manipulated for attenuation of viral replication. PMID:27062995

  6. 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.

  7. Modeling Intrinsic Heterogeneity and Growth of Cancer Cells

    PubMed Central

    Greene, James M.; Levy, Doron; Fung, King L.; Silva de Souza, Paloma; Gottesman, Michael M.; Lavi, Orit

    2014-01-01

    Intratumoral heterogeneity has been found to be a major cause of drug resistance. Cell-to-cell variation increases as a result of cancer-related alterations, which are acquired by stochastic events and further induced by environmental signals. However, most cellular mechanisms include natural fluctuations that are closely regulated, and thus lead to asynchronization of the cells, which causes intrinsic heterogeneity in a given population. Here, we derive two novel mathematical models, a stochastic agent-based model and an integro-differential equation model, each of which describes the growth of cancer cells as a dynamic transition between proliferative and quiescent states. These models are designed to predict variations in growth as a function of the intrinsic heterogeneity emerging from the durations of the cell-cycle and apoptosis, and also include cellular density dependencies. By examining the role all parameters play in the evolution of intrinsic tumor heterogeneity, and the sensitivity of the population growth to parameter values, we show that the cell-cycle length has the most significant effect on the growth dynamics. In addition, we demonstrate that the agent-based model can be approximated well by the more computationally efficient integro-differential equations when the number of cells is large. This essential step in cancer growth modeling will allow us to revisit the mechanisms of multi-drug resistance by examining spatiotemporal differences of cell growth while administering a drug among the different sub-populations in a single tumor, as well as the evolution of those mechanisms as a function of the resistance level. PMID:25457229

  8. Robust active binocular vision through intrinsically motivated learning

    PubMed Central

    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

  9. 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

  10. 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

  11. 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

  12. 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

  13. Intrinsic Stability of the Smallest Possible Silver Nanotube

    NASA Astrophysics Data System (ADS)

    Autreto, P. A. S.; Lagos, M. J.; Sato, F.; Bettini, J.; Rocha, A. R.; Rodrigues, V.; Ugarte, D.; Galvao, D. S.

    2011-02-01

    Recently, Lagos et al. [Nature Nanotech. 4, 149 (2009)1748-338710.1038/nnano.2008.414] reported the discovery of the smallest possible Ag nanotube with a square cross section. Ab initio density functional theory calculations strongly support that the stability of these hollow structures is structurally intrinsic and not the result of contamination by light atoms. We also report the first experimental observation of the theoretically predicted corrugation of the hollow structure. Quantum conductance calculations predict a unique signature of 3.6G0 for this new family of nanotubes.

  14. 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.

  15. 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.

  16. Diffractive Higgs production from intrinsic heavy flavors in the proton

    SciTech Connect

    Brodsky, Stanley J.; Kopeliovich, Boris; Schmidt, Ivan; Soffer, Jacques

    2006-06-01

    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 the 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.

  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. 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.

  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. Photoemission from graphite: Intrinsic and self-energy effects

    SciTech Connect

    Strocov, V. N.; Charrier, A.; Themlin, J.-M.; Rohlfing, M.; Claessen, R.; Barrett, N.; Avila, J.; Sanchez, J.; Asensio, M.-C.

    2001-08-15

    We report a photoemission study on high-quality single-crystal graphite epitaxially grown on SiC. The results are interpreted using independent information on the final states obtained by very-low-energy electron diffraction. Significant intrinsic photoemission and surface effects are identified, which distort the photoemission response and narrow the observed dispersion range of the {pi} state. We assess its true dispersion range using a model photoemission calculation. A significant dependence of the excited-state self-energy effects on the wave-function character is found. The experimental results are compared with a GW calculation.

  1. Representation of a gauge field via intrinsic "BRST" operator

    NASA Astrophysics Data System (ADS)

    Batalin, Igor A.; Lavrov, Peter M.

    2015-11-01

    We show that there exists a representation of a matrix-valued gauge field via intrinsic "BRST" operator assigned to matrix-valued generators of a gauge algebra. In this way, we reproduce the standard formulation of the ordinary Yang-Mills theory. In the case of a generating quasigroup/groupoid, we give a natural counterpart to the Yang-Mills action. The latter counterpart does also apply as to the most general case of an involution for matrix-valued gauge generators.

  2. Hypofractionated Radiotherapy for Children With Diffuse Intrinsic Pontine Gliomas.

    PubMed

    Hankinson, Todd C; Patibandla, Mohana Rao; Green, Adam; Hemenway, Molly; Foreman, Nicholas; Handler, Michael; Liu, Arthur K

    2016-04-01

    Children with diffuse intrinsic pontine gliomas have very poor outcomes, with nearly all children dying from disease. Standard therapy includes 6 weeks of radiation. There have been descriptions of using a shortened course of radiation. We describe our experience with a hypofractionated radiotherapy approach delivered over five treatments. In seven children, hypofractionated radiotherapy was well tolerated, but symptomatic radiation necrosis was seen in three of the children. Overall survival was slightly shorter than previously described in the literature. We are developing a prospective dose-finding protocol with the goal of tolerable short-course radiation treatment with outcomes comparable to conventional radiation. PMID:26544789

  3. [Skin aging: Molecular understanding of extrinsic and intrinsic processes].

    PubMed

    Makrantonaki, E; Vogel, M; Scharffetter-Kochanek, K; Zouboulis, C C

    2015-10-01

    In an ever-aging society, a better understanding of the underlying mechanisms accompanying skin aging has become essential. Most age-related morphological skin changes are triggered by a combination of intrinsic factors (e.g., genetics, hormones) and extrinsic ones (e.g., ultarviolet/infrared light exposure, smoking, pollution). In this article, new insights on the latest findings regarding the pathogenesis of skin aging are summarised, addressing the extent to which the aforementioned factorsmay influence the progress of skin aging and identifying the consequences on the morphology and physiology of skin. PMID:26385893

  4. Radius of gyration and intrinsic viscosity of polyelectrolyte solutions

    SciTech Connect

    Milas, M.; Borsali, R.; Rinaudo, M.

    1993-12-31

    Relatively low molecular weights polyelectrolytes (10{sup 4}-10{sup 6}) behave as worm-like chain when electrostatic repulsions are assumed to govern the excluded volume parameter. Under such conditions, predictions of chain expansion and effect of polyelectrolyte concentrations are made assuming that unperturbed dimensions could be obtained at infinite salt content. Experimental studies of an ionic polysaccharide, namely the Na-hyaluronate, were done and the values obtained for the radius of gyration as well as the intrinsic viscosity at different charge densities are in good agreement with the predictions.

  5. Intrinsic fundamental frequency of vowels is moderated by regional dialect

    PubMed Central

    Jacewicz, Ewa; Fox, Robert Allen

    2015-01-01

    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

  6. 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.

  7. Intrinsic interface states in InAs-AlSb heterostructures.

    PubMed

    Raouafi, F; Benchamekh, R; Nestoklon, M O; Jancu, J-M; Voisin, P

    2016-02-01

    We examine the formation of intrinsic interface states bound to the plane of In-Sb chemical bonds at InAs-AlSb interfaces. Careful parameterization of the bulk materials in the frame of the extended-basis spds (*)tight-binding model and recent progress in predictions of band offsets severely limit the span of tight-binding parameters describing this system. We find that a heavy-hole-like interface state bound to the plane of In-Sb bonds exists for a large range of values of the InSb-InAs band offset. PMID:26732184

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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%.

  14. The intrinsic fraction of broad-absorption line quasars

    NASA Astrophysics Data System (ADS)

    Knigge, Christian; Scaringi, Simone; Goad, Michael R.; Cottis, Christopher E.

    2008-05-01

    We carefully reconsider the problem of classifying broad-absorption line quasars (BALQSOs) and derive a new, unbiased estimate of the intrinsic BALQSO fraction from the Sloan Digital Sky Survey (SDSS) DR3 quasi-stellar object (QSO) catalogue. We first show that the distribution of objects selected by the so-called `absorption index' (AI) is clearly bimodal in logAI, with only one mode corresponding to definite BALQSOs. The surprisingly high BALQSO fractions that have recently been inferred from AI-based samples are therefore likely to be overestimated. We then present two new approaches to the classification problem that are designed to be more robust than the AI, but also more complete than the traditional `balnicity index' (BI). Both approaches yield observed BALQSO fractions around 13.5 per cent, while a conservative third approach suggests an upper limit of 18.3 per cent. Finally, we discuss the selection biases that affect our observed BALQSO fraction. After correcting for these biases, we arrive at our final estimate of the intrinsic BALQSO fraction. This is fBALQSO = 0.17 +/- 0.01(stat) +/- 0.03(sys) with an upper limit of fBALQSO ~= 0.23. We conclude by pointing out that the bimodality of the logAI distribution may be evidence that the BAL-forming region has clearly delineated physical boundaries.

  15. 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.

  16. Direct mapping of hippocampal surfaces with intrinsic shape context.

    PubMed

    Shi, Yonggang; Thompson, Paul M; de Zubicaray, Greig I; Rose, Stephen E; Tu, Zhuowen; Dinov, Ivo; Toga, Arthur W

    2007-09-01

    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's 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 on temporal changes of HC asymmetry in AD. PMID:17625918

  17. 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. PMID:22738789

  18. Intrinsic viscosity and related parameters of PEOX aqueous solutions

    NASA Astrophysics Data System (ADS)

    Tothova, J.; Paulovicova, K.; Kopcansky, P.; Timko, M.; Lisy, V.

    2015-12-01

    Poly(2-ethyl-2-oxazoline) (PEOX) is a polymer used in many applications. In this work we present the steady-state shear viscosity experiment on low-concentrated high-molecular PEOX aqueous solutions near the presumed theta temperature. In the interpretation of these experiments we consider the polymer being partially permeable to water, with a finite draining parameter h, contrary to the usual approach when the polymer coil is assumed to be impermeable and h approaches the infinite value. By this way we have determined important polymer parameters, such as the gyration and hydrodynamic radii. The calculated Huggins coefficient kH was compared to its value extracted from the measured intrinsic viscosity. We have found that at the temperature 20°C the theoretically predicted kH(h) agrees with the experiment. Since the theory is built for the theta condition, we propose that the theta temperature for PEOX is notably lower than 25°C known from the previous studies. This finding is supported by our measurements of the dependence of the intrinsic viscosity on the PEOX molecular weight.

  19. Altered striatal intrinsic functional connectivity in pediatric anxiety.

    PubMed

    Dorfman, Julia; Benson, Brenda; Farber, Madeline; Pine, Daniel; Ernst, Monique

    2016-05-01

    Anxiety disorders are among the most common psychiatric disorders of adolescence. Behavioral and task-based imaging studies implicate altered reward system function, including striatal dysfunction, in adolescent anxiety. However, no study has yet examined alterations of the striatal intrinsic functional connectivity in adolescent anxiety disorders. The current study examines striatal intrinsic functional connectivity (iFC), using six bilateral striatal seeds, among 35 adolescents with anxiety disorders and 36 healthy comparisons. Anxiety is associated with abnormally low iFC within the striatum (e.g., between nucleus accumbens and caudate nucleus), and between the striatum and prefrontal regions, including subgenual anterior cingulate cortex, posterior insula and supplementary motor area. The current findings extend prior behavioral and task-based imaging research, and provide novel data implicating decreased striatal iFC in adolescent anxiety. Alterations of striatal neurocircuitry identified in this study may contribute to the perturbations in the processing of motivational, emotional, interoceptive, and motor information seen in pediatric anxiety disorders. This pattern of the striatal iFC perturbations can guide future research on specific mechanisms underlying anxiety. PMID:27004799

  20. 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

  1. Natural protein sequences are more intrinsically disordered than random sequences.

    PubMed

    Yu, Jia-Feng; Cao, Zanxia; Yang, Yuedong; Wang, Chun-Ling; Su, Zhen-Dong; Zhao, Ya-Wei; Wang, Ji-Hua; Zhou, Yaoqi

    2016-08-01

    Most natural protein sequences have resulted from millions or even billions of years of evolution. How they differ from random sequences is not fully understood. Previous computational and experimental studies of random proteins generated from noncoding regions yielded inclusive results due to species-dependent codon biases and GC contents. Here, we approach this problem by investigating 10,000 sequences randomized at the amino acid level. Using well-established predictors for protein intrinsic disorder, we found that natural sequences have more long disordered regions than random sequences, even when random and natural sequences have the same overall composition of amino acid residues. We also showed that random sequences are as structured as natural sequences according to contents and length distributions of predicted secondary structure, although the structures from random sequences may be in a molten globular-like state, according to molecular dynamics simulations. The bias of natural sequences toward more intrinsic disorder suggests that natural sequences are created and evolved to avoid protein aggregation and increase functional diversity. PMID:26801222

  2. 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.

  3. Intrinsic, nondeterministic circadian rhythm generation in identified mammalian neurons

    PubMed Central

    Webb, Alexis B.; Angelo, Nikhil; Huettner, James E.; Herzog, Erik D.

    2009-01-01

    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/mm2 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

  4. 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

  5. Quantitative proteome-based guidelines for intrinsic disorder characterization.

    PubMed

    Vincent, Michael; Whidden, Mark; Schnell, Santiago

    2016-06-01

    Intrinsically disordered proteins fail to adopt a stable three-dimensional structure under physiological conditions. It is now understood that many disordered proteins are not dysfunctional, but instead engage in numerous cellular processes, including signaling and regulation. Disorder characterization from amino acid sequence relies on computational disorder prediction algorithms. While numerous large-scale investigations of disorder have been performed using these algorithms, and have offered valuable insight regarding the prevalence of protein disorder in many organisms, critical proteome-based descriptive statistical guidelines that would enable the objective assessment of intrinsic disorder in a protein of interest remain to be established. Here we present a quantitative characterization of numerous disorder features using a rigorous non-parametric statistical approach, providing expected values and percentile cutoffs for each feature in ten eukaryotic proteomes. Our estimates utilize multiple ab initio disorder prediction algorithms grounded on physicochemical principles. Furthermore, we present novel threshold values, specific to both the prediction algorithms and the proteomes, defining the longest primary sequence length in which the significance of a continuous disordered region can be evaluated on the basis of length alone. The guidelines presented here are intended to improve the interpretation of disorder content and continuous disorder predictions from the proteomic point of view. PMID:27085142

  6. The importance of intrinsic disorder for protein phosphorylation.

    PubMed

    Iakoucheva, Lilia M; Radivojac, Predrag; Brown, Celeste J; O'Connor, Timothy R; Sikes, Jason G; Obradovic, Zoran; Dunker, A Keith

    2004-01-01

    Reversible protein phosphorylation provides a major regulatory mechanism in eukaryotic cells. Due to the high variability of amino acid residues flanking a relatively limited number of experimentally identified phosphorylation sites, reliable prediction of such sites still remains an important issue. Here we report the development of a new web-based tool for the prediction of protein phosphorylation sites, DISPHOS (DISorder-enhanced PHOSphorylation predictor, http://www.ist.temple. edu/DISPHOS). We observed that amino acid compositions, sequence complexity, hydrophobicity, charge and other sequence attributes of regions adjacent to phosphorylation sites are very similar to those of intrinsically disordered protein regions. Thus, DISPHOS uses position-specific amino acid frequencies and disorder information to improve the discrimination between phosphorylation and non-phosphorylation sites. Based on the estimates of phosphorylation rates in various protein categories, the outputs of DISPHOS are adjusted in order to reduce the total number of misclassified residues. When tested on an equal number of phosphorylated and non-phosphorylated residues, the accuracy of DISPHOS reaches 76% for serine, 81% for threonine and 83% for tyrosine. The significant enrichment in disorder-promoting residues surrounding phosphorylation sites together with the results obtained by applying DISPHOS to various protein functional classes and proteomes, provide strong support for the hypothesis that protein phosphorylation predominantly occurs within intrinsically disordered protein regions. PMID:14960716

  7. 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.

  8. Tractography from HARDI using an Intrinsic Unscented Kalman Filter

    PubMed Central

    Cheng, Guang; Salehian, Hesamoddin; Forder, John R.; Vemuri, Baba C.

    2014-01-01

    A novel adaptation of the unscented Kalman filter (UKF) was recently introduced in literature for simultaneous multi-tensor 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 multi-tensor 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 multi-tensors 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. PMID:25203986

  9. 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. PMID:26105981

  10. 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.

  11. 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. PMID:24187325

  12. 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. PMID:25203986

  13. Constrained molecular dynamics for quantifying intrinsic ductility versus brittleness

    NASA Astrophysics Data System (ADS)

    Tanguy, D.

    2007-10-01

    Evaluating the critical load levels for intrinsic ductility and brittle propagation is a first, but necessary, step for modeling semibrittle crack propagation. In the most general case, the calculations have to be fully atomistic because the details of the crack tip structure cannot be captured by continuum mechanics. In this paper, we present a method to explore ductile and brittle configurations, within the same force field, giving a quantitative estimate of the proximity of a transition from intrinsic ductility to brittleness. The shear localization is characterized by a centrosymmetry criterion evaluated on each atom in the vicinity of the crack tip. This provides an efficient order parameter to track the nucleation and propagation of dislocations. We show that it can be used as a holonomic constraint within molecular dynamics simulations, giving a precise control over plasticity during crack propagation. The equations of motion are derived and applied to crack propagation in the [112¯] direction of an fcc crystal loaded in mode I along [111]. The critical loads for dislocation emission and for brittle propagation are computed. The key point is that the generalized forces of constraint are not dissipative. Therefore, they do not spoil the critical elastic energy release rates (the Griffith criterion is preserved). As an example of the possibilities of the method, the response of blunted tips is investigated for three configurations: a slab of vacancies, an elliptical hole, and a circular hole. Brittle propagation by an alternative mechanism to cleavage, called “vacancy injection,” is reported.

  14. 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.

  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. 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

  17. Nicotinic modulation of intrinsic brain networks in schizophrenia

    PubMed Central

    Smucny, Jason; Tregellas, Jason

    2014-01-01

    The nicotinic receptor is a promising drug target currently being investigated for the treatment of cognitive symptoms in schizophrenia. A key step in this process is the development of noninvasive functional neuroimaging biomarkers that can be used to determine if nicotinic agents are eliciting their targeted biological effect, ideally through modulation of a fundamental aspect of neuronal function. To that end, neuroimaging researchers are beginning to understand how nicotinic modulation affects “intrinsic” brain networks to elicit potentially therapeutic effects. An intrinsic network is a functionally and (often) structurally connected network of brain areas whose activity reflects a fundamental neurobiological organizational principle of the brain. This review summarizes findings of the effects of nicotinic drugs on three topics related to intrinsic brain network activity: (1) the default mode network, a group of brain areas for which activity is maximal at rest and reduced during cognitive tasks, (2) the salience network, which integrates incoming sensory data with prior internal representations to guide future actions and change predictive values, and (3) multi-scale complex network dynamics, which describe these brain’s ability to efficiency integrate information while preserving local functional specialization. These early findings can be used to inform future neuroimaging studies that examine the network effects of nicotinic agents. PMID:23796751

  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. Intrinsic Size Parameters for Palmitoylated and Carboxyamidomethylated Peptides

    PubMed Central

    Li, Zhiyu; Dilger, Jonathan M.; Pejaver, Vikas; Smiley, David; Arnold, Randy J.; Mooney, Sean D.; Mukhopadhyay, Suchetana; Radivojac, Predrag; Clemmer, David E.

    2015-01-01

    Cross sections for 61 palmitoylated peptides and 73 cysteine-unmodified peptides are determined and used together with a previously obtained tryptic peptide library to derive a set of intrinsic size parameters (ISPs) for the palmitoyl (Pal) group (1.26 ± 0.04), carboxyamidomethyl (Am) group (0.92 ± 0.04), and the 20 amino acid residues to assess the influence of Pal- and Am-modification on cysteine and other amino acid residues. These values highlight the influence of the intrinsic hydrophobic and hydrophilic nature of these modifications on the overall cross sections. As a part of this analysis, we find that ISPs derived from a database of a modifier on one amino acid residue (CysPal) can be applied on the same modification group on different amino acid residues (SerPal and TyrPal). Using these ISP values, we are able to calculate peptide cross sections to within ± 2% of experimental values for 83% of Pal-modified peptide ions and 63% of Am-modified peptide ions. We propose that modification groups should be treated as individual contribution factors, instead of treating the combination of the particular group and the amino acid residue they are on as a whole when considering their effects on the peptide ion mobility features. PMID:26023288

  20. 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