Trans-cis switching mechanisms in proline analogues and their relevance for the gating of the 5-HT3 receptor.

PubMed

Melis, Claudio; Bussi, Giovanni; Lummis, Sarah C R; Molteni, Carla

2009-09-03

Trans-cis isomerization of a proline peptide bond is a potential mechanism to open the channel of the 5-HT(3) receptor. Here, we have used the metadynamics method to theoretically explore such a mechanism. We have determined the free energy surfaces in aqueous solution of a series of dipeptides of proline analogues and evaluated the free energy difference between the cis and trans isomers. These theoretical results were then compared with data from mutagenesis experiments, in which the response of the 5-HT(3) receptor was measured when the proline at the apex of the M2-M3 transmembrane domain loop was mutated. The strong correlation between the experimental and the theoretical data supports the existence of a trans-cis proline switch for opening the 5-HT(3) receptor ion channel.

Citronellal assumes a folded conformation in solution due to dispersion interactions: A joint NMR-DFT analysis

NASA Astrophysics Data System (ADS)

Nardini, Viviani; Dias, Luis Gustavo; Palaretti, Vinicius; da Silva, Gil Valdo José

2018-04-01

Citronellal, an acyclic monoterpenoid, is a small molecule suitable for systematic scanning of its conformational geometric parameters in solution or in the gas phase. We have studied the conformational distribution of citronellal by correlating its structure and theoretical chemical shifts with nuclear magnetic resonance data. Interestingly, folded conformations were the most relevant, as confirmed by NOE experiments. We concluded that the conformational distribution is due to intramolecular dispersion interactions.

The Role of Subtropical Intrusion in the Development of Typhoon Usagi (5W) 2007

DTIC Science & Technology

2008-03-01

THE MARSUPIAL PARADIGM Summarizing the DMW08 theory, the relevant theoretical paradigm is the formation of a closed proto-vortex or “ embryo ...and begins control its own destiny . By correlating the marsupial analogy for TC formation in this study, we can verify in theory that the remnants...The hurricane embryo . Talk presented at short program workshop entitled Small scale and extreme events: The Hurricane, NSF Institute for Pure and

Broadband photon-photon interactions mediated by cold atoms in a photonic crystal fiber

PubMed Central

Litinskaya, Marina; Tignone, Edoardo; Pupillo, Guido

2016-01-01

We demonstrate theoretically that photon-photon attraction can be engineered in the continuum of scattering states for pairs of photons propagating in a hollow-core photonic crystal fiber filled with cold atoms. The atoms are regularly spaced in an optical lattice configuration and the photons are resonantly tuned to an internal atomic transition. We show that the hard-core repulsion resulting from saturation of the atomic transitions induces bunching in the photonic component of the collective atom-photon modes (polaritons). Bunching is obtained in a frequency range as large as tens of GHz, and can be controlled by the inter-atomic separation. We provide a fully analytical explanation for this phenomenon by proving that correlations result from a mismatch of the quantization volumes for atomic excitations and photons in the continuum. Even stronger correlations can be observed for in-gap two-polariton bound states. Our theoretical results use parameters relevant for current experiments and suggest a simple and feasible way to induce interactions between photons. PMID:27170160

Attitudes without Objects: Evidence for a Dispositional Attitude, its Measurement, and its Consequences

PubMed Central

Hepler, Justin; Albarracin, Dolores

2013-01-01

We hypothesized that individuals may differ in the dispositional tendency to have positive versus negative attitudes, a trait termed the Dispositional Attitude. Across four studies, we developed a 16-item Dispositional Attitude Measure (DAM) and investigated its internal consistency, test-retest reliability, factor structure, convergent validity, discriminant validity, and predictive validity. DAM scores were (a) positively correlated with positive affect traits, curiosity-related traits, and individual pre-existing attitudes, (b) negatively correlated with negative affect traits, and (c) uncorrelated with theoretically unrelated traits. Dispositional attitudes also significantly predicted the valence of novel attitudes while controlling for theoretically relevant traits (such as the big-five and optimism). The dispositional attitude construct represents a new perspective in which attitudes are not simply a function of the properties of the stimuli under consideration, but are also a function of the properties of the evaluator. We discuss the intriguing implications of dispositional attitudes for many areas of research, including attitude formation, persuasion, and behavior prediction. PMID:23586409

Attitudes without objects: evidence for a dispositional attitude, its measurement, and its consequences.

PubMed

Hepler, Justin; Albarracín, Dolores

2013-06-01

We hypothesized that individuals may differ in the dispositional tendency to have positive vs. negative attitudes, a trait termed the dispositional attitude. Across 4 studies, we developed a 16-item Dispositional Attitude Measure (DAM) and investigated its internal consistency, test-retest reliability, factor structure, convergent validity, discriminant validity, and predictive validity. DAM scores were (a) positively correlated with positive affect traits, curiosity-related traits, and individual preexisting attitudes; (b) negatively correlated with negative affect traits; and (c) uncorrelated with theoretically unrelated traits. Dispositional attitudes also significantly predicted the valence of novel attitudes while controlling for theoretically relevant traits (such as the Big 5 and optimism). The dispositional attitude construct represents a new perspective in which attitudes are not simply a function of the properties of the stimuli under consideration, but are also a function of the properties of the evaluator. We discuss the intriguing implications of dispositional attitudes for many areas of research, including attitude formation, persuasion, and behavior prediction. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Improving the theoretical prediction for the Bs - B̅s width difference: matrix elements of next-to-leading order ΔB = 2 operators

NASA Astrophysics Data System (ADS)

Davies, Christine; Harrison, Judd; Lepage, G. Peter; Monahan, Christopher; Shigemitsu, Junko; Wingate, Matthew

2018-03-01

We present lattice QCD results for the matrix elements of R2 and other dimension-7, ΔB = 2 operators relevant for calculations of Δs, the Bs - B̅s width difference. We have computed correlation functions using 5 ensembles of the MILC Collaboration's 2+1 + 1-flavour gauge field configurations, spanning 3 lattice spacings and light sea quarks masses down to the physical point. The HISQ action is used for the valence strange quarks, and the NRQCD action is used for the bottom quarks. Once our analysis is complete, the theoretical uncertainty in the Standard Model prediction for ΔΓs will be substantially reduced.

Can one trust quantum simulators?

PubMed

Hauke, Philipp; Cucchietti, Fernando M; Tagliacozzo, Luca; Deutsch, Ivan; Lewenstein, Maciej

2012-08-01

Various fundamental phenomena of strongly correlated quantum systems such as high-T(c) superconductivity, the fractional quantum-Hall effect and quark confinement are still awaiting a universally accepted explanation. The main obstacle is the computational complexity of solving even the most simplified theoretical models which are designed to capture the relevant quantum correlations of the many-body system of interest. In his seminal 1982 paper (Feynman 1982 Int. J. Theor. Phys. 21 467), Richard Feynman suggested that such models might be solved by 'simulation' with a new type of computer whose constituent parts are effectively governed by a desired quantum many-body dynamics. Measurements on this engineered machine, now known as a 'quantum simulator,' would reveal some unknown or difficult to compute properties of a model of interest. We argue that a useful quantum simulator must satisfy four conditions: relevance, controllability, reliability and efficiency. We review the current state of the art of digital and analog quantum simulators. Whereas so far the majority of the focus, both theoretically and experimentally, has been on controllability of relevant models, we emphasize here the need for a careful analysis of reliability and efficiency in the presence of imperfections. We discuss how disorder and noise can impact these conditions, and illustrate our concerns with novel numerical simulations of a paradigmatic example: a disordered quantum spin chain governed by the Ising model in a transverse magnetic field. We find that disorder can decrease the reliability of an analog quantum simulator of this model, although large errors in local observables are introduced only for strong levels of disorder. We conclude that the answer to the question 'Can we trust quantum simulators?' is … to some extent.

Can one trust quantum simulators?

NASA Astrophysics Data System (ADS)

Hauke, Philipp; Cucchietti, Fernando M.; Tagliacozzo, Luca; Deutsch, Ivan; Lewenstein, Maciej

2012-08-01

Various fundamental phenomena of strongly correlated quantum systems such as high-Tc superconductivity, the fractional quantum-Hall effect and quark confinement are still awaiting a universally accepted explanation. The main obstacle is the computational complexity of solving even the most simplified theoretical models which are designed to capture the relevant quantum correlations of the many-body system of interest. In his seminal 1982 paper (Feynman 1982 Int. J. Theor. Phys. 21 467), Richard Feynman suggested that such models might be solved by ‘simulation’ with a new type of computer whose constituent parts are effectively governed by a desired quantum many-body dynamics. Measurements on this engineered machine, now known as a ‘quantum simulator,’ would reveal some unknown or difficult to compute properties of a model of interest. We argue that a useful quantum simulator must satisfy four conditions: relevance, controllability, reliability and efficiency. We review the current state of the art of digital and analog quantum simulators. Whereas so far the majority of the focus, both theoretically and experimentally, has been on controllability of relevant models, we emphasize here the need for a careful analysis of reliability and efficiency in the presence of imperfections. We discuss how disorder and noise can impact these conditions, and illustrate our concerns with novel numerical simulations of a paradigmatic example: a disordered quantum spin chain governed by the Ising model in a transverse magnetic field. We find that disorder can decrease the reliability of an analog quantum simulator of this model, although large errors in local observables are introduced only for strong levels of disorder. We conclude that the answer to the question ‘Can we trust quantum simulators?’ is … to some extent.

Associations between informant ratings of personality disorder traits, self-reports of personality, and directly observed behavior.

PubMed

Kaurin, Aleksandra; Sauerberger, Kyle S; Funder, David C

2018-03-02

Diagnoses of personality disorders (PD) must rely on judgments of observers-either clinicians or acquaintances-because personality disorders are primarily defined in terms of maladaptive interpersonal behavior. Little is known, however, about how closely acquaintances' judgments of PD traits relate to self-reports of theoretically relevant Big Five traits or directly observed behavioral outcomes in interpersonal situations. The present study examines associations between judgments of the 10 PD traits provided by close acquaintances, self-reports of PD-relevant Big Five personality traits, and observed interpersonal behaviors across three different three-person laboratory interactions (i.e., unstructured chat, cooperative task, competitive game). The sample consisted of 256 undergraduate students (130 females; M age  = 19.83, SD = 1.25). Four unacquainted observers independently rated participants' behaviors from video recordings. In line with previous work, informant reports of PD traits demonstrate strong convergent validity with relevant self-reported Big Five traits (as identified by Lynam & Widiger, 2001). Directly observed behavior is meaningfully associated with acquaintances' judgments and self-reports of PD-relevant traits, and the associations between these judgments and behavior are strongest for traits associated with histrionic and schizoid PD. Vector correlations between behavioral profiles associated with informant and self-reports show that both assessments have similar behavioral correlates. Associations between PD trait ratings and behavior appeared to differ as a function of gender, with males showing more and stronger correlations. Informants' ratings of PD traits are impressively accurate, converging both with self-reports of relevant traits and directly observed interpersonal behavior. Therefore, a comprehensive understanding of PDs and associated traits can be augmented by information from multiple acquaintances who have the opportunity to observe how an individual interacts with others on a daily basis across diverse contexts. © 2018 Wiley Periodicals, Inc.

Physics of the Kitaev Model: Fractionalization, Dynamic Correlations, and Material Connections

NASA Astrophysics Data System (ADS)

Hermanns, M.; Kimchi, I.; Knolle, J.

2018-03-01

Quantum spin liquids have fascinated condensed matter physicists for decades because of their unusual properties such as spin fractionalization and long-range entanglement. Unlike conventional symmetry breaking, the topological order underlying quantum spin liquids is hard to detect experimentally. Even theoretical models are scarce for which the ground state is established to be a quantum spin liquid. The Kitaev honeycomb model and its generalizations to other tricoordinated lattices are chief counterexamples - they are exactly solvable, harbor a variety of quantum spin liquid phases, and are also relevant for certain transition metal compounds including the polymorphs of (Na,Li)2IrO3 iridates and RuCl3. In this review, we give an overview of the rich physics of the Kitaev model, including two-dimensional and three-dimensional fractionalization as well as dynamic correlations and behavior at finite temperatures. We discuss the different materials and argue how the Kitaev model physics can be relevant even though most materials show magnetic ordering at low temperatures.

Imaging episodic memory: implications for cognitive theories and phenomena.

PubMed

Nyberg, L

1999-01-01

Functional neuroimaging studies are beginning to identify neuroanatomical correlates of various cognitive functions. This paper presents results relevant to several theories and phenomena of episodic memory, including component processes of episodic retrieval, encoding specificity, inhibition, item versus source memory, encoding-retrieval overlap, and the picture-superiority effect. Overall, by revealing specific activation patterns, the results provide support for existing theoretical views and they add some unique information which may be important to consider in future attempts to develop cognitive theories of episodic memory.

Positive emotion, appraisal, and the role of appraisal overlap in positive emotion co-occurrence.

PubMed

Tong, Eddie M W; Jia, Lile

2017-02-01

Appraisal research has traditionally focused on negative emotions but has not addressed issues concerning the relationships between several positive emotions and appraisals in daily life and the extent to which co-occurrence of positive emotions can be explained by overlap in appraisals. Driven by a priori hypotheses on appraisal-emotion relationships, this study investigated 12 positive emotions and 13 appraisal dimensions using Ecological Momentary Assessment. The results provide strong evidence that positive emotions and appraisals correlate significantly in daily life. Importantly, we found that the positive emotions' overlap on theoretically relevant, as compared to irrelevant, appraisals was stronger and more predictive of their co-occurrence. Furthermore, appraisal overlap on theoretically relevant appraisals predicted the co-occurrence of positive emotions even when the appraisal of pleasantness was excluded, indicating that positive emotions do not co-occur just by virtue of their shared valence. Our findings affirmed and refined the appraisal profiles of positive emotions and underscore the importance of appraisals in accounting for the commonality and differences among positive emotions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Theoretical Studies of the Kinetics of First-Order Phase Transitions.

NASA Astrophysics Data System (ADS)

Zheng, Qiang

This thesis involves theoretical studies of the kinetics of orderings in three classes of systems. The first class involves problems of phase separation in which the order parameter is conserved, such as occurs in the binary alloy Al-Zn. A theory is developed for the late stages of phase separation in the droplet regime for two -dimensional systems, namely, Ostwald ripening in two dimensions. The theory considers droplet correlations, which was neglected before, by a proper treatment of the screening effect of the correlations. This correlation effect is found that it does not alert the scaling features of phase separation, but significantly changes the shape of droplet-size distribution function. Further experiments and computer simulations are needed before this long-time subject may be closed. A second class of problem involves a study of the finite-size effects on domain growth described by the Allen-Cahn dynamics. Based on a theoretical approach of Ohta, Jasnow, and Kawasaki the explicit scaling functions for the scattering intensity for hypercubes and films are obtained. These results are for the cases in which the order-parameter is not conserved, such as in an order-disorder transition in alloys. These studies will be relevant to the experimental and computer simulation research projects currently being carried out in the United States and Europe. The last class of problems involves orderings in strong correlated systems, namely, the growth of Breath Figures. A special feature of this class of problems is that the coalescence effect. A theoretical model is proposed which can handle the two growth mechanisms, the individual droplet growth and coalescence simultaneously. Under certain approximations, the droplet-size distribution function is obtained analytically, and is in qualitative agreement with computer simulations. Our model also suggests that there may be an interesting relationship between the growth of Breath Figures and a geometric structure (ultrametricity) of general complex systems.

Control of Multilayer Networks

PubMed Central

Menichetti, Giulia; Dall’Asta, Luca; Bianconi, Ginestra

2016-01-01

The controllability of a network is a theoretical problem of relevance in a variety of contexts ranging from financial markets to the brain. Until now, network controllability has been characterized only on isolated networks, while the vast majority of complex systems are formed by multilayer networks. Here we build a theoretical framework for the linear controllability of multilayer networks by mapping the problem into a combinatorial matching problem. We found that correlating the external signals in the different layers can significantly reduce the multiplex network robustness to node removal, as it can be seen in conjunction with a hybrid phase transition occurring in interacting Poisson networks. Moreover we observe that multilayer networks can stabilize the fully controllable multiplex network configuration that can be stable also when the full controllability of the single network is not stable. PMID:26869210

Some New Theoretical Issues in Systems Thinking Relevant for Modelling Corporate Learning

ERIC Educational Resources Information Center

Minati, Gianfranco

2007-01-01

Purpose: The purpose of this paper is to describe fundamental concepts and theoretical challenges with regard to systems, and to build on these in proposing new theoretical frameworks relevant to learning, for example in so-called learning organizations. Design/methodology/approach: The paper focuses on some crucial fundamental aspects introduced…

Simple and Multivariate Relationships Between Spiritual Intelligence with General Health and Happiness.

PubMed

Amirian, Mohammad-Elyas; Fazilat-Pour, Masoud

2016-08-01

The present study examined simple and multivariate relationships of spiritual intelligence with general health and happiness. The employed method was descriptive and correlational. King's Spiritual Quotient scales, GHQ-28 and Oxford Happiness Inventory, are filled out by a sample consisted of 384 students, which were selected using stratified random sampling from the students of Shahid Bahonar University of Kerman. Data are subjected to descriptive and inferential statistics including correlations and multivariate regressions. Bivariate correlations support positive and significant predictive value of spiritual intelligence toward general health and happiness. Further analysis showed that among the Spiritual Intelligence' subscales, Existential Critical Thinking Predicted General Health and Happiness, reversely. In addition, happiness was positively predicted by generation of personal meaning and transcendental awareness. The findings are discussed in line with the previous studies and the relevant theoretical background.

Evidence-based selection of theories for designing behaviour change interventions: using methods based on theoretical construct domains to understand clinicians' blood transfusion behaviour.

PubMed

Francis, Jill J; Stockton, Charlotte; Eccles, Martin P; Johnston, Marie; Cuthbertson, Brian H; Grimshaw, Jeremy M; Hyde, Chris; Tinmouth, Alan; Stanworth, Simon J

2009-11-01

Many theories of behaviour are potentially relevant to predictive and intervention studies but most studies investigate a narrow range of theories. Michie et al. (2005) agreed 12 'theoretical domains' from 33 theories that explain behaviour change. They developed a 'Theoretical Domains Interview' (TDI) for identifying relevant domains for specific clinical behaviours, but the framework has not been used for selecting theories for predictive studies. It was used here to investigate clinicians' transfusion behaviour in intensive care units (ICU). Evidence suggests that red blood cells transfusion could be reduced for some patients without reducing quality of care. (1) To identify the domains relevant to transfusion practice in ICUs and neonatal intensive care units (NICUs), using the TDI. (2) To use the identified domains to select appropriate theories for a study predicting transfusion behaviour. An adapted TDI about managing a patient with borderline haemoglobin by watching and waiting instead of transfusing red blood cells was used to conduct semi-structured, one-to-one interviews with 18 intensive care consultants and neonatologists across the UK. Relevant theoretical domains were: knowledge, beliefs about capabilities, beliefs about consequences, social influences, behavioural regulation. Further analysis at the construct level resulted in selection of seven theoretical approaches relevant to this context: Knowledge-Attitude-Behaviour Model, Theory of Planned Behaviour, Social Cognitive Theory, Operant Learning Theory, Control Theory, Normative Model of Work Team Effectiveness and Action Planning Approaches. This study illustrated, the use of the TDI to identify relevant domains in a complex area of inpatient care. This approach is potentially valuable for selecting theories relevant to predictive studies and resulted in greater breadth of potential explanations than would be achieved if a single theoretical model had been adopted.

a Theoretical Characterization of Electronic States of CH2IOO and CH2OO Radicals Relevant to the Near IR Region

NASA Astrophysics Data System (ADS)

Dawes, Richard; Lolur, Phalgun; Huang, Meng; Kline, Neal; Miller, Terry A.

2015-06-01

Criegee intermediates (R1R2COO or CIs) arise from ozonolysis of biogenic and anthropogenic alkenes, which is an important process in the atmosphere. Recent breakthroughs in producing them in the gas phase have resulted in a flurry of experimental and theoretical studies. Producing the simplest CI (CH2OO) in the lab via photolysis of CH2I2 in the presence of O2 yields both CH2OO and CH2IOO with pressure dependent branching. As discussed in the preceding talk, both species might be expected to have electronic transitions in the near IR (NIR). Here we discuss electronic structure calculations used to characterize the electronic states of both systems in the relevant energy range. Using explicitly-correlated multireference configuration interaction (MRCI-F12) and coupled-cluster (UCCSD(T)-F12b) calculations we were first able to exclude CH2OO as the carrier of the observed NIR spectrum. Next, by computing frequencies and relaxed full torsional scans for the ~A and ~X states, we were able to aid in analysis and assignment of the NIR spectrum attributed to CH2IOO.

The C2HDM revisited

NASA Astrophysics Data System (ADS)

Fontes, Duarte; Mühlleitner, Margarete; Romão, Jorge C.; Santos, Rui; Silva, João P.; Wittbrodt, Jonas

2018-02-01

The complex two-Higgs doublet model is one of the simplest ways to extend the scalar sector of the Standard Model to include a new source of CP-violation. The model has been used as a benchmark model to search for CP-violation at the LHC and as a possible explanation for the matter-antimatter asymmetry of the Universe. In this work, we re-analyse in full detail the softly broken ℤ 2 symmetric complex two-Higgs doublet model (C2HDM). We provide the code C2HDM_HDECAY implementing the C2HDM in the well-known HDECAY program which calculates the decay widths including the state-of-the-art higher order QCD corrections and the relevant off-shell decays. Using C2HDM_HDECAY together with the most relevant theoretical and experimental constraints, including electric dipole moments (EDMs), we review the parameter space of the model and discuss its phenomenology. In particular, we find cases where large CP-odd couplings to fermions are still allowed and provide benchmark points for these scenarios. We examine the prospects of discovering CP-violation at the LHC and show how theoretically motivated measures of CP-violation correlate with observables.

Visual Masking in Schizophrenia: Overview and Theoretical Implications

PubMed Central

Green, Michael F.; Lee, Junghee; Wynn, Jonathan K.; Mathis, Kristopher I.

2011-01-01

Visual masking provides several key advantages for exploring the earliest stages of visual processing in schizophrenia: it allows for control over timing at the millisecond level, there are several well-supported theories of the underlying neurobiology of visual masking, and it is amenable to examination by electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI). In this paper, we provide an overview of the visual masking impairment schizophrenia, including the relevant theoretical mechanisms for masking impairment. We will discuss its relationship to clinical symptoms, antipsychotic medications, diagnostic specificity, and presence in at-risk populations. As part of this overview, we will cover the neural correlates of visual masking based on recent findings from EEG and fMRI. Finally, we will suggest a possible mechanism that could explain the patterns of masking findings and other visual processing findings in schizophrenia. PMID:21606322

Consciousness Regained: Disentangling Mechanisms, Brain Systems, and Behavioral Responses

PubMed Central

2017-01-01

How consciousness (experience) arises from and relates to material brain processes (the “mind-body problem”) has been pondered by thinkers for centuries, and is regarded as among the deepest unsolved problems in science, with wide-ranging theoretical, clinical, and ethical implications. Until the last few decades, this was largely seen as a philosophical topic, but not widely accepted in mainstream neuroscience. Since the 1980s, however, novel methods and theoretical advances have yielded remarkable results, opening up the field for scientific and clinical progress. Since a seminal paper by Crick and Koch (1998) claimed that a science of consciousness should first search for its neural correlates (NCC), a variety of correlates have been suggested, including both content-specific NCCs, determining particular phenomenal components within an experience, and the full NCC, the neural substrates supporting entire conscious experiences. In this review, we present recent progress on theoretical, experimental, and clinical issues. Specifically, we (1) review methodological advances that are important for dissociating conscious experience from related enabling and executive functions, (2) suggest how critically reconsidering the role of the frontal cortex may further delineate NCCs, (3) advocate the need for general, objective, brain-based measures of the capacity for consciousness that are independent of sensory processing and executive functions, and (4) show how animal studies can reveal population and network phenomena of relevance for understanding mechanisms of consciousness. PMID:29118218

Correlated Observations, the Law of Small Numbers and Bank Runs

PubMed Central

2016-01-01

Empirical descriptions and studies suggest that generally depositors observe a sample of previous decisions before deciding if to keep their funds deposited or to withdraw them. These observed decisions may exhibit different degrees of correlation across depositors. In our model depositors decide sequentially and are assumed to follow the law of small numbers in the sense that they believe that a bank run is underway if the number of observed withdrawals in their sample is large. Theoretically, with highly correlated samples and infinite depositors runs occur with certainty, while with random samples it needs not be the case, as for many parameter settings the likelihood of bank runs is zero. We investigate the intermediate cases and find that i) decreasing the correlation and ii) increasing the sample size reduces the likelihood of bank runs, ceteris paribus. Interestingly, the multiplicity of equilibria, a feature of the canonical Diamond-Dybvig model that we use also, disappears almost completely in our setup. Our results have relevant policy implications. PMID:27035435

Correlated Observations, the Law of Small Numbers and Bank Runs.

PubMed

Horváth, Gergely; Kiss, Hubert János

2016-01-01

Empirical descriptions and studies suggest that generally depositors observe a sample of previous decisions before deciding if to keep their funds deposited or to withdraw them. These observed decisions may exhibit different degrees of correlation across depositors. In our model depositors decide sequentially and are assumed to follow the law of small numbers in the sense that they believe that a bank run is underway if the number of observed withdrawals in their sample is large. Theoretically, with highly correlated samples and infinite depositors runs occur with certainty, while with random samples it needs not be the case, as for many parameter settings the likelihood of bank runs is zero. We investigate the intermediate cases and find that i) decreasing the correlation and ii) increasing the sample size reduces the likelihood of bank runs, ceteris paribus. Interestingly, the multiplicity of equilibria, a feature of the canonical Diamond-Dybvig model that we use also, disappears almost completely in our setup. Our results have relevant policy implications.

Structural and spectroscopic characterization of methyl isocyanate, methyl cyanate, methyl fulminate, and acetonitrile N-oxide using highly correlated ab initio methods.

PubMed

Dalbouha, S; Senent, M L; Komiha, N; Domínguez-Gómez, R

2016-09-28

Various astrophysical relevant molecules obeying the empirical formula C 2 H 3 NO are characterized using explicitly correlated coupled cluster methods (CCSD(T)-F12). Rotational and rovibrational parameters are provided for four isomers: methyl isocyanate (CH 3 NCO), methyl cyanate (CH 3 OCN), methyl fulminate (CH 3 ONC), and acetonitrile N-oxide (CH 3 CNO). A CH 3 CON transition state is inspected. A variational procedure is employed to explore the far infrared region because some species present non-rigidity. Second order perturbation theory is used for the determination of anharmonic frequencies, rovibrational constants, and to predict Fermi resonances. Three species, methyl cyanate, methyl fulminate, and CH 3 CON, show a unique methyl torsion hindered by energy barriers. In methyl isocyanate, the methyl group barrier is so low that the internal top can be considered a free rotor. On the other hand, acetonitrile N-oxide presents a linear skeleton, C 3v symmetry, and free internal rotation. Its equilibrium geometry depends strongly on electron correlation. The remaining isomers present a bend skeleton. Divergences between theoretical rotational constants and previous parameters fitted from observed lines for methyl isocyanate are discussed on the basis of the relevant rovibrational interaction and the quasi-linearity of the molecular skeleton.

Structural and spectroscopic characterization of methyl isocyanate, methyl cyanate, methyl fulminate, and acetonitrile N-oxide using highly correlated ab initio methods

NASA Astrophysics Data System (ADS)

Dalbouha, S.; Senent, M. L.; Komiha, N.; Domínguez-Gómez, R.

2016-09-01

Various astrophysical relevant molecules obeying the empirical formula C2H3NO are characterized using explicitly correlated coupled cluster methods (CCSD(T)-F12). Rotational and rovibrational parameters are provided for four isomers: methyl isocyanate (CH3NCO), methyl cyanate (CH3OCN), methyl fulminate (CH3ONC), and acetonitrile N-oxide (CH3CNO). A CH3CON transition state is inspected. A variational procedure is employed to explore the far infrared region because some species present non-rigidity. Second order perturbation theory is used for the determination of anharmonic frequencies, rovibrational constants, and to predict Fermi resonances. Three species, methyl cyanate, methyl fulminate, and CH3CON, show a unique methyl torsion hindered by energy barriers. In methyl isocyanate, the methyl group barrier is so low that the internal top can be considered a free rotor. On the other hand, acetonitrile N-oxide presents a linear skeleton, C3v symmetry, and free internal rotation. Its equilibrium geometry depends strongly on electron correlation. The remaining isomers present a bend skeleton. Divergences between theoretical rotational constants and previous parameters fitted from observed lines for methyl isocyanate are discussed on the basis of the relevant rovibrational interaction and the quasi-linearity of the molecular skeleton.

The Causal Effects of Cultural Relevance: Evidence from an Ethnic Studies Curriculum

ERIC Educational Resources Information Center

Dee, Thomas S.; Penner, Emily K.

2017-01-01

An extensive theoretical and qualitative literature stresses the promise of instructional practices and content aligned with minority students' experiences. Ethnic studies courses provide an example of such "culturally relevant pedagogy" (CRP). Despite theoretical support, quantitative evidence on the effectiveness of these courses is…

Cognitive-behavioural theories of helplessness/hopelessness: valid models of depression?

PubMed

Henkel, V; Bussfeld, P; Möller, H-J; Hegerl, U

2002-10-01

Helplessness and hopelessness are central aspects of cognitive-behavioural explanations for the development and persistence of depression. In this article a general overview concerning the evolution of those approaches to depression is provided. Included is a critical examination of the theories. The review of the literature suggests that those cognitive models describing helplessness/hopelessness as trait factors mediating depression do not really have a strong empirical base. The majority of those studies had been conducted in healthy or only mildly depressed subjects. Thus, there seems to be little justification for broad generalisations beyond the populations studied. It seems that some of the reported studies have not tested the underlying theories adequately (e. g. correlation had sometimes been interpreted as causation; adequate prospective longitudinal study designs had seldom been applied). Moreover, the theoretical models are not generally prepared to explain all depressive features (e. g. the possibility of a spontaneous shift in a manic episode). Despite those limitations, there is a relevant impact of the learned helplessness paradigm on preclinical research in neurobiological correlates of depressive states. Last but not least, the models are of high interest with respect to the theoretical background of important modules of cognitive-behavioural therapy and its acute and prophylactic effects.

Hardy's test as a device-independent dimension witness

NASA Astrophysics Data System (ADS)

Mukherjee, Amit; Roy, Arup; Bhattacharya, Some Sankar; Das, Subhadipa; Gazi, Md. Rajjak; Banik, Manik

2015-08-01

Knowing the dimension of an unknown physical system has practical relevance, as dimensionality plays an important role in various information theoretic tasks. In this work we show that a modified version of Hardy's argument, which reveals the contradiction of quantum theory with local realism, turns out to be useful for inspecting the minimal subsystem dimension of an unknown correlated quantum system. The use of Hardy's test in this task has a novel advantage: the subsystem dimension can be determined without knowing the detailed functioning of the experimental devices; i.e., Hardy's test suffices to be a device-independent dimension witness.

Correlation of molecular valence- and K-shell photoionization resonances with bond lengths

NASA Technical Reports Server (NTRS)

Sheehy, J. A.; Gil, T. J.; Winstead, C. L.; Farren, R. E.; Langhoff, P. W.

1989-01-01

The relationship between the interatomic distance and the positions of valence-shell and K-shell sigma(asterisk) photoionization resonances is investigated theoretically for the molecules C2, F2, N2, O2, CO, NO, C2H2, C2H4, C2H6, HCN, H2CO, N20, CO2, and C2N2. The results of molecular-orbital computations are presented in three-dimensional diagrams, which are shown to be similar to the wave functions of a particle in a cylindrical well, confirming the validity of free-electron molecular-orbital (FEMO) approximations for modeling the potential along the symmetry axis. FEMO orbital energies and resonance positions are found to be in good agreement with previous theoretical and experimental results. Also included is a Feshbach-Fano analysis of the relevance of virtual-valence orbitals to the appearance of single-channel resonances in molecular photoionization cross sections.

Middle Childhood Attachment Strategies: validation of an observational measure.

PubMed

Brumariu, Laura E; Giuseppone, Kathryn R; Kerns, Kathryn A; Van de Walle, Magali; Bureau, Jean-François; Bosmans, Guy; Lyons-Ruth, Karlen

2018-02-05

The purpose of this study was to assess behavioral manifestations of attachment in middle childhood, and to evaluate their relations with key theoretical correlates. The sample consisted of 87 children (aged 10-12 years) and their mothers. Dyads participated in an 8-min videotaped discussion of a conflict in their relationships, later scored with the Middle Childhood Attachment Strategies Coding System (MCAS) for key features of all child attachment patterns described in previous literature (secure, ambivalent, avoidant, disorganized-disoriented, caregiving/role-confused, hostile/punitive). To assess validity, relations among MCAS dimensions and other measures of attachment, parenting, and psychological adjustment were evaluated. Results provide preliminary evidence for the psychometric properties of the MCAS in that its behaviorally assessed patterns were associated with theoretically relevant constructs, including maternal warmth/acceptance and psychological control, and children's social competence, depression, and behavioral problems. The MCAS opens new grounds for expanding our understanding of attachment and its outcomes in middle childhood.

How absent negativity relates to affect and motivation: an integrative relief model.

PubMed

Deutsch, Roland; Smith, Kevin J M; Kordts-Freudinger, Robert; Reichardt, Regina

2015-01-01

The present paper concerns the motivational underpinnings and behavioral correlates of the prevention or stopping of negative stimulation - a situation referred to as relief. Relief is of great theoretical and applied interest. Theoretically, it is tied to theories linking affect, emotion, and motivational systems. Importantly, these theories make different predictions regarding the association between relief and motivational systems. Moreover, relief is a prototypical antecedent of counterfactual emotions, which involve specific cognitive processes compared to factual or mere anticipatory emotions. Practically, relief may be an important motivator of addictive and phobic behaviors, self destructive behaviors, and social influence. In the present paper, we will first provide a review of conflicting conceptualizations of relief. We will then present an integrative relief model (IRMO) that aims at resolving existing theoretical conflicts. We then review evidence relevant to distinctive predictions regarding the moderating role of various procedural features of relief situations. We conclude that our integrated model results in a better understanding of existing evidence on the affective and motivational underpinnings of relief, but that further evidence is needed to come to a more comprehensive evaluation of the viability of IRMO.

Correlation, temperature and disorder: Recent developments in the one-step description of angle-resolved photoemission

NASA Astrophysics Data System (ADS)

Braun, Jürgen; Minár, Ján; Ebert, Hubert

2018-04-01

Various apparative developments extended the potential of angle-resolved photoemission spectroscopy tremendously during the last two decades. Modern experimental arrangements consisting of new photon sources, analyzers and detectors supply not only extremely high angle and energy resolution but also spin resolution. This provides an adequate platform to study in detail new materials like low-dimensional magnetic structures, Rashba systems, topological insulator materials or high TC superconductors. The interest in such systems has grown enormously not only because of their technological relevance but even more because of exciting new physics. Furthermore, the use of photon energies from few eV up to several keV makes this experimental technique a rather unique tool to investigate the electronic properties of solids and surfaces. The following article reviews the corresponding recent theoretical developments in the field of angle-resolved photoemission with a special emphasis on correlation effects, temperature and relativistic aspects. The most successful theoretical approach to deal with angle-resolved photoemission is the so-called spectral function or one-step formulation of the photoemission process. Nowadays, the one-step model allows for photocurrent calculations for photon energies ranging from a few eV to more than 10 keV, to deal with arbitrarily ordered and disordered systems, to account for finite temperatures, and considering in addition strong correlation effects within the dynamical mean-field theory or similar advanced approaches.

Nonlocality in many-body quantum systems detected with two-body correlators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tura, J., E-mail: jordi.tura@icfo.es; Augusiak, R.; Sainz, A.B.

Contemporary understanding of correlations in quantum many-body systems and in quantum phase transitions is based to a large extent on the recent intensive studies of entanglement in many-body systems. In contrast, much less is known about the role of quantum nonlocality in these systems, mostly because the available multipartite Bell inequalities involve high-order correlations among many particles, which are hard to access theoretically, and even harder experimentally. Standard, “theorist- and experimentalist-friendly” many-body observables involve correlations among only few (one, two, rarely three...) particles. Typically, there is no multipartite Bell inequality for this scenario based on such low-order correlations. Recently, however,more » we have succeeded in constructing multipartite Bell inequalities that involve two- and one-body correlations only, and showed how they revealed the nonlocality in many-body systems relevant for nuclear and atomic physics [Tura et al., Science 344 (2014) 1256]. With the present contribution we continue our work on this problem. On the one hand, we present a detailed derivation of the above Bell inequalities, pertaining to permutation symmetry among the involved parties. On the other hand, we present a couple of new results concerning such Bell inequalities. First, we characterize their tightness. We then discuss maximal quantum violations of these inequalities in the general case, and their scaling with the number of parties. Moreover, we provide new classes of two-body Bell inequalities which reveal nonlocality of the Dicke states—ground states of physically relevant and experimentally realizable Hamiltonians. Finally, we shortly discuss various scenarios for nonlocality detection in mesoscopic systems of trapped ions or atoms, and by atoms trapped in the vicinity of designed nanostructures.« less

High-resolution tungsten spectroscopy relevant to the diagnostic of high-temperature tokamak plasmas

NASA Astrophysics Data System (ADS)

Rzadkiewicz, J.; Yang, Y.; Kozioł, K.; O'Mullane, M. G.; Patel, A.; Xiao, J.; Yao, K.; Shen, Y.; Lu, D.; Hutton, R.; Zou, Y.; JET Contributors

2018-05-01

The x-ray transitions in Cu- and Ni-like tungsten ions in the 5.19-5.26 Å wavelength range that are relevant as a high-temperature tokamak diagnostic, in particular for JET in the ITER-like wall configuration, have been studied. Tungsten spectra were measured at the upgraded Shanghai- Electron Beam Ion Trap operated with electron-beam energies from 3.16 to 4.55 keV. High-resolution measurements were performed by means of a flat Si 111 crystal spectrometer equipped by a CCD camera. The experimental wavelengths were determined with an accuracy of 0.3-0.4 mÅ. The wavelength of the ground-state transition in Cu-like tungsten from the 3 p53 d104 s 4 d [ (3/2 ,(1/2,5/2 ) 2] 1 /2 level was measured. All measured wavelengths were compared with those measured from JET ITER-like wall plasmas and with other experiments and various theoretical predictions including cowan, relac, multiconfigurational Dirac-Fock (MCDF), and fac calculations. To obtain a higher accuracy from theoretical predictions, the MCDF calculations were extended by taking into account correlation effects (configuration-interaction approach). It was found that such an extension brings the calculations closer to the experimental values in comparison with other calculations.

Friendly Home and Inhabitants' Morality: Mutual Relationships.

PubMed

Nartova-Bochaver, Sofya K; Kuznetsova, Valeriya B

2017-01-01

The study is aimed at investigating the connection between the friendliness of the home environment and the moral motives' level. The friendliness of the home environment includes two aspects: the number of functions provided by home (functionality) and the congruence of these functions with inhabitants' needs (relevance). The theoretical framework of the study was formed by research and ideas emphasizing the interplay between people and their environments. We hypothesized that the friendliness of the home environment and inhabitants' moral motives would have a reciprocal relationship: the friendlier the home the higher the inhabitants' moral motives' level, and, vice versa, the higher the person's moral motives' level the more positive home image. The respondents were 550 students (25% male). The Home Environment Functionality Questionnaire, the Home Environment Relevance Questionnaire, and the Moral Motivation Model Scale were used. As expected, it was found that the friendliness of the home environment and the inhabitants' moral motives are in reciprocal synergetic relationships. Relevance formed more nuanced correlation patterns with moral motives than functionality did. Functionality predicted moral motives poorly whereas moral motives predicted functionality strongly. Finally, relevance and moral motives were found to be in mutual relationships whereas the perceived functionality was predicted by moral motives only.

Friendly Home and Inhabitants' Morality: Mutual Relationships

PubMed Central

Nartova-Bochaver, Sofya K.; Kuznetsova, Valeriya B.

2018-01-01

The study is aimed at investigating the connection between the friendliness of the home environment and the moral motives' level. The friendliness of the home environment includes two aspects: the number of functions provided by home (functionality) and the congruence of these functions with inhabitants' needs (relevance). The theoretical framework of the study was formed by research and ideas emphasizing the interplay between people and their environments. We hypothesized that the friendliness of the home environment and inhabitants' moral motives would have a reciprocal relationship: the friendlier the home the higher the inhabitants' moral motives' level, and, vice versa, the higher the person's moral motives' level the more positive home image. The respondents were 550 students (25% male). The Home Environment Functionality Questionnaire, the Home Environment Relevance Questionnaire, and the Moral Motivation Model Scale were used. As expected, it was found that the friendliness of the home environment and the inhabitants' moral motives are in reciprocal synergetic relationships. Relevance formed more nuanced correlation patterns with moral motives than functionality did. Functionality predicted moral motives poorly whereas moral motives predicted functionality strongly. Finally, relevance and moral motives were found to be in mutual relationships whereas the perceived functionality was predicted by moral motives only. PMID:29375450

Consciousness Regained: Disentangling Mechanisms, Brain Systems, and Behavioral Responses.

PubMed

Storm, Johan F; Boly, Mélanie; Casali, Adenauer G; Massimini, Marcello; Olcese, Umberto; Pennartz, Cyriel M A; Wilke, Melanie

2017-11-08

How consciousness (experience) arises from and relates to material brain processes (the "mind-body problem") has been pondered by thinkers for centuries, and is regarded as among the deepest unsolved problems in science, with wide-ranging theoretical, clinical, and ethical implications. Until the last few decades, this was largely seen as a philosophical topic, but not widely accepted in mainstream neuroscience. Since the 1980s, however, novel methods and theoretical advances have yielded remarkable results, opening up the field for scientific and clinical progress. Since a seminal paper by Crick and Koch (1998) claimed that a science of consciousness should first search for its neural correlates (NCC), a variety of correlates have been suggested, including both content-specific NCCs, determining particular phenomenal components within an experience, and the full NCC, the neural substrates supporting entire conscious experiences. In this review, we present recent progress on theoretical, experimental, and clinical issues. Specifically, we (1) review methodological advances that are important for dissociating conscious experience from related enabling and executive functions, (2) suggest how critically reconsidering the role of the frontal cortex may further delineate NCCs, (3) advocate the need for general, objective, brain-based measures of the capacity for consciousness that are independent of sensory processing and executive functions, and (4) show how animal studies can reveal population and network phenomena of relevance for understanding mechanisms of consciousness. Copyright © 2017 the authors 0270-6474/17/3710882-12$15.00/0.

Renormalization group methods for the Reynolds stress transport equations

NASA Technical Reports Server (NTRS)

Rubinstein, R.

1992-01-01

The Yakhot-Orszag renormalization group is used to analyze the pressure gradient-velocity correlation and return to isotropy terms in the Reynolds stress transport equations. The perturbation series for the relevant correlations, evaluated to lowest order in the epsilon-expansion of the Yakhot-Orszag theory, are infinite series in tensor product powers of the mean velocity gradient and its transpose. Formal lowest order Pade approximations to the sums of these series produce a rapid pressure strain model of the form proposed by Launder, Reece, and Rodi, and a return to isotropy model of the form proposed by Rotta. In both cases, the model constants are computed theoretically. The predicted Reynolds stress ratios in simple shear flows are evaluated and compared with experimental data. The possibility is discussed of deriving higher order nonlinear models by approximating the sums more accurately. The Yakhot-Orszag renormalization group provides a systematic procedure for deriving turbulence models. Typical applications have included theoretical derivation of the universal constants of isotropic turbulence theory, such as the Kolmogorov constant, and derivation of two equation models, again with theoretically computed constants and low Reynolds number forms of the equations. Recent work has applied this formalism to Reynolds stress modeling, previously in the form of a nonlinear eddy viscosity representation of the Reynolds stresses, which can be used to model the simplest normal stress effects. The present work attempts to apply the Yakhot-Orszag formalism to Reynolds stress transport modeling.

A quantitative estimate of schema abnormality in socially anxious and non-anxious individuals.

PubMed

Wenzel, Amy; Brendle, Jennifer R; Kerr, Patrick L; Purath, Donna; Ferraro, F Richard

2007-01-01

Although cognitive theories of anxiety suggest that anxious individuals are characterized by abnormal threat-relevant schemas, few empirical studies have estimated the nature of these cognitive structures using quantitative methods that lend themselves to inferential statistical analysis. In the present study, socially anxious (n = 55) and non-anxious (n = 62) participants completed 3 Q-Sort tasks to assess their knowledge of events that commonly occur in social or evaluative scenarios. Participants either sorted events according to how commonly they personally believe the events occur (i.e. "self" condition), or to how commonly they estimate that most people believe they occur (i.e. "other" condition). Participants' individual Q-Sorts were correlated with mean sorts obtained from a normative sample to obtain an estimate of schema abnormality, with lower correlations representing greater levels of abnormality. Relative to non-anxious participants, socially anxious participants' sorts were less strongly associated with sorts of the normative sample, particularly in the "self" condition, although secondary analyses suggest that some significant results might be explained, in part, by depression and experience with the scenarios. These results provide empirical support for the theoretical notion that threat-relevant self-schemas of anxious individuals are characterized by some degree of abnormality.

Theory of Excitonic Delocalization for Robust Vibronic Dynamics in LH2.

PubMed

Caycedo-Soler, Felipe; Lim, James; Oviedo-Casado, Santiago; van Hulst, Niek F; Huelga, Susana F; Plenio, Martin B

2018-06-11

Nonlinear spectroscopy has revealed long-lasting oscillations in the optical response of a variety of photosynthetic complexes. Different theoretical models that involve the coherent coupling of electronic (excitonic) or electronic-vibrational (vibronic) degrees of freedom have been put forward to explain these observations. The ensuing debate concerning the relevance of either mechanism may have obscured their complementarity. To illustrate this balance, we quantify how the excitonic delocalization in the LH2 unit of Rhodopseudomonas acidophila purple bacterium leads to correlations of excitonic energy fluctuations, relevant coherent vibronic coupling, and importantly, a decrease in the excitonic dephasing rates. Combining these effects, we identify a feasible origin for the long-lasting oscillations observed in fluorescent traces from time-delayed two-pulse single-molecule experiments performed on this photosynthetic complex and use this approach to discuss the role of this complementarity in other photosynthetic systems.

Substance abuse prevention intervention research with Hispanic populations.

PubMed

Castro, Felipe González; Barrera, Manuel; Pantin, Hilda; Martinez, Charles; Felix-Ortiz, Maria; Rios, Rebeca; Lopez, Vera A; Lopez, Cristy

2006-09-01

Selected studies with specific relevance to substance abuse prevention interventions with Hispanic youth and families were examined to identify prior findings and emerging issues that may guide the design of future substance abuse prevention intervention research and its implementation with Hispanic populations. The origins of prevention research and role of risk and protective factors are examined, including culturally-specific risk and protective factors for Hispanic populations. Correlational studies, non-experimental interventions, and randomized controlled trials were examined for the period of 1974-2003. The literature search yielded 15 articles selected for this review that exhibited adequate methodological rigor. An added search for more recent studies identified three additional articles, for a total of 18 prevention intervention articles that were reviewed. Theoretical and methodological issues and recommendations are presented for future research aimed at improving the efficacy and effectiveness of future prevention intervention studies and their cultural relevance for Hispanic populations.

Renormalization group analysis of the Reynolds stress transport equation

NASA Technical Reports Server (NTRS)

Rubinstein, R.; Barton, J. M.

1992-01-01

The pressure velocity correlation and return to isotropy term in the Reynolds stress transport equation are analyzed using the Yakhot-Orszag renormalization group. The perturbation series for the relevant correlations, evaluated to lowest order in the epsilon-expansion of the Yakhot-Orszag theory, are infinite series in tensor product powers of the mean velocity gradient and its transpose. Formal lowest order Pade approximations to the sums of these series produce a fast pressure strain model of the form proposed by Launder, Reece, and Rodi, and a return to isotropy model of the form proposed by Rotta. In both cases, the model constant are computed theoretically. The predicted Reynolds stress ratios in simple shear flows are evaluated and compared with experimental data. The possibility is discussed of driving higher order nonlinear models by approximating the sums more accurately.

Factorization and resummation for groomed multi-prong jet shapes

NASA Astrophysics Data System (ADS)

Larkoski, Andrew J.; Moult, Ian; Neill, Duff

2018-02-01

Observables which distinguish boosted topologies from QCD jets are playing an increasingly important role at the Large Hadron Collider (LHC). These observables are often used in conjunction with jet grooming algorithms, which reduce contamination from both theoretical and experimental sources. In this paper we derive factorization formulae for groomed multi-prong substructure observables, focusing in particular on the groomed D 2 observable, which is used to identify boosted hadronic decays of electroweak bosons at the LHC. Our factorization formulae allow systematically improvable calculations of the perturbative D 2 distribution and the resummation of logarithmically enhanced terms in all regions of phase space using renormalization group evolution. They include a novel factorization for the production of a soft subjet in the presence of a grooming algorithm, in which clustering effects enter directly into the hard matching. We use these factorization formulae to draw robust conclusions of experimental relevance regarding the universality of the D 2 distribution in both e + e - and pp collisions. In particular, we show that the only process dependence is carried by the relative quark vs. gluon jet fraction in the sample, no non-global logarithms from event-wide correlations are present in the distribution, hadronization corrections are controlled by the perturbative mass of the jet, and all global color correlations are completely removed by grooming, making groomed D 2 a theoretically clean QCD observable even in the LHC environment. We compute all ingredients to one-loop accuracy, and present numerical results at next-to-leading logarithmic accuracy for e + e - collisions, comparing with parton shower Monte Carlo simulations. Results for pp collisions, as relevant for phenomenology at the LHC, are presented in a companion paper [1].

Observability of radiation-pressure shot noise in optomechanical systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boerkje, K.; Nunnenkamp, A.; Zwickl, B. M.

2010-07-15

We present a theoretical study of an experiment designed to detect radiation-pressure shot noise in an optomechanical system. Our model consists of a coherently driven optical cavity mode that is coupled to a mechanical oscillator. We examine the cross-correlation between two quadratures of the output field from the cavity. We determine under which circumstances radiation-pressure shot noise can be detected by a measurement of this cross-correlation. This is done in the general case of nonzero detuning between the frequency of the drive and the cavity resonance frequency. We study the qualitative features of the different contributions to the cross-correlator andmore » provide quantitative figures of merit for the relative importance of the radiation-pressure shot noise contribution to other contributions. We also propose a modified setup of this experiment relevant to the 'membrane-in-the-middle' geometry, which potentially can avoid the problems of static bistability and classical noise in the drive.« less

Correlation analysis of targeted proteins and metabolites to assess and engineer microbial isopentenol production.

PubMed

George, Kevin W; Chen, Amy; Jain, Aakriti; Batth, Tanveer S; Baidoo, Edward E K; Wang, George; Adams, Paul D; Petzold, Christopher J; Keasling, Jay D; Lee, Taek Soon

2014-08-01

The ability to rapidly assess and optimize heterologous pathway function is critical for effective metabolic engineering. Here, we develop a systematic approach to pathway analysis based on correlations between targeted proteins and metabolites and apply it to the microbial production of isopentenol, a promising biofuel. Starting with a seven-gene pathway, we performed a correlation analysis to reduce pathway complexity and identified two pathway proteins as the primary determinants of efficient isopentenol production. Aided by the targeted quantification of relevant pathway intermediates, we constructed and subsequently validated a conceptual model of isopentenol pathway function. Informed by our analysis, we assembled a strain which produced isopentenol at a titer 1.5 g/L, or 46% of theoretical yield. Our engineering approach allowed us to accurately identify bottlenecks and determine appropriate pathway balance. Paired with high-throughput cloning techniques and analytics, this strategy should prove useful for the analysis and optimization of increasingly complex heterologous pathways. © 2014 Wiley Periodicals, Inc.

Microstructural Effects on Initiation Behavior in HMX

NASA Astrophysics Data System (ADS)

Molek, Christopher; Welle, Eric; Hardin, Barrett; Vitarelli, Jim; Wixom, Ryan; Samuels, Philip

Understanding the role microstructure plays on ignition and growth behavior has been the subject of a significant body of research within the detonation physics community. The pursuit of this understanding is important because safety and performance characteristics have been shown to strongly correlate to particle morphology. Historical studies have often correlated bulk powder characteristics to the performance or safety characteristics of pressed materials. We believe that a clearer and more relevant correlation is made between the pressed microstructure and the observed detonation behavior. This type of assessment is possible, as techniques now exist for the quantification of the pressed microstructures. Our talk will report on experimental efforts that correlate directly measured microstructural characteristics to initiation threshold behavior of HMX based materials. The internal microstructures were revealed using an argon ion cross-sectioning technique. This technique enabled the quantification of density and interface area of the pores within the pressed bed using methods of stereology. These bed characteristics are compared to the initiation threshold behavior of three HMX based materials using an electric gun based test method. Finally, a comparison of experimental threshold data to supporting theoretical efforts will be made.

Properties of atomic pairs produced in the collision of Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Ziń, Paweł; Wasak, Tomasz

2018-04-01

During a collision of Bose-Einstein condensates correlated pairs of atoms are emitted. The scattered massive particles, in analogy to photon pairs in quantum optics, might be used in the violation of Bell's inequalities, demonstration of Einstein-Podolsky-Rosen correlations, or sub-shot-noise atomic interferometry. Usually, a theoretical description of the collision relies either on stochastic numerical methods or on analytical treatments involving various approximations. Here, we investigate elastic scattering of atoms from colliding elongated Bose-Einstein condensates within the Bogoliubov method, carefully controlling performed approximations at every stage of the analysis. We derive expressions for the one- and two-particle correlation functions. The obtained formulas, which relate the correlation functions to the condensate wave function, are convenient for numerical calculations. We employ the variational approach for condensate wave functions to obtain analytical expressions for the correlation functions, whose properties we analyze in detail. We also present a useful semiclassical model of the process and compare its results with the quantum one. The results are relevant for recent experiments with excited helium atoms, as well as for planned experiments aimed at investigating the nonclassicality of the system.

A unified approach to the study of temporal, correlational, and rate coding.

PubMed

Panzeri, S; Schultz, S R

2001-06-01

We demonstrate that the information contained in the spike occurrence times of a population of neurons can be broken up into a series of terms, each reflecting something about potential coding mechanisms. This is possible in the coding regime in which few spikes are emitted in the relevant time window. This approach allows us to study the additional information contributed by spike timing beyond that present in the spike counts and to examine the contributions to the whole information of different statistical properties of spike trains, such as firing rates and correlation functions. It thus forms the basis for a new quantitative procedure for analyzing simultaneous multiple neuron recordings and provides theoretical constraints on neural coding strategies. We find a transition between two coding regimes, depending on the size of the relevant observation timescale. For time windows shorter than the timescale of the stimulus-induced response fluctuations, there exists a spike count coding phase, in which the purely temporal information is of third order in time. For time windows much longer than the characteristic timescale, there can be additional timing information of first order, leading to a temporal coding phase in which timing information may affect the instantaneous information rate. In this new framework, we study the relative contributions of the dynamic firing rate and correlation variables to the full temporal information, the interaction of signal and noise correlations in temporal coding, synergy between spikes and between cells, and the effect of refractoriness. We illustrate the utility of the technique by analyzing a few cells from the rat barrel cortex.

Statistical analysis of magnetically soft particles in magnetorheological elastomers

NASA Astrophysics Data System (ADS)

Gundermann, T.; Cremer, P.; Löwen, H.; Menzel, A. M.; Odenbach, S.

2017-04-01

The physical properties of magnetorheological elastomers (MRE) are a complex issue and can be influenced and controlled in many ways, e.g. by applying a magnetic field, by external mechanical stimuli, or by an electric potential. In general, the response of MRE materials to these stimuli is crucially dependent on the distribution of the magnetic particles inside the elastomer. Specific knowledge of the interactions between particles or particle clusters is of high relevance for understanding the macroscopic rheological properties and provides an important input for theoretical calculations. In order to gain a better insight into the correlation between the macroscopic effects and microstructure and to generate a database for theoretical analysis, x-ray micro-computed tomography (X-μCT) investigations as a base for a statistical analysis of the particle configurations were carried out. Different MREs with quantities of 2-15 wt% (0.27-2.3 vol%) of iron powder and different allocations of the particles inside the matrix were prepared. The X-μCT results were edited by an image processing software regarding the geometrical properties of the particles with and without the influence of an external magnetic field. Pair correlation functions for the positions of the particles inside the elastomer were calculated to statistically characterize the distributions of the particles in the samples.

Ultracold Anions for High-Precision Antihydrogen Experiments

NASA Astrophysics Data System (ADS)

Cerchiari, G.; Kellerbauer, A.; Safronova, M. S.; Safronova, U. I.; Yzombard, P.

2018-03-01

Experiments with antihydrogen (H ¯) for a study of matter-antimatter symmetry and antimatter gravity require ultracold H ¯ to reach ultimate precision. A promising path towards antiatoms much colder than a few kelvin involves the precooling of antiprotons by laser-cooled anions. Because of the weak binding of the valence electron in anions—dominated by polarization and correlation effects—only few candidate systems with suitable transitions exist. We report on a combination of experimental and theoretical studies to fully determine the relevant binding energies, transition rates, and branching ratios of the most promising candidate La- . Using combined transverse and collinear laser spectroscopy, we determined the resonant frequency of the laser cooling transition to be ν =96.592 713 (91 ) THz and its transition rate to be A =4.90 (50 )×104 s-1 . Using a novel high-precision theoretical treatment of La- we calculated yet unmeasured energy levels, transition rates, branching ratios, and lifetimes to complement experimental information on the laser cooling cycle of La- . The new data establish the suitability of La- for laser cooling and show that the cooling transition is significantly stronger than suggested by a previous theoretical study.

How absent negativity relates to affect and motivation: an integrative relief model

PubMed Central

Deutsch, Roland; Smith, Kevin J. M.; Kordts-Freudinger, Robert; Reichardt, Regina

2015-01-01

The present paper concerns the motivational underpinnings and behavioral correlates of the prevention or stopping of negative stimulation – a situation referred to as relief. Relief is of great theoretical and applied interest. Theoretically, it is tied to theories linking affect, emotion, and motivational systems. Importantly, these theories make different predictions regarding the association between relief and motivational systems. Moreover, relief is a prototypical antecedent of counterfactual emotions, which involve specific cognitive processes compared to factual or mere anticipatory emotions. Practically, relief may be an important motivator of addictive and phobic behaviors, self destructive behaviors, and social influence. In the present paper, we will first provide a review of conflicting conceptualizations of relief. We will then present an integrative relief model (IRMO) that aims at resolving existing theoretical conflicts. We then review evidence relevant to distinctive predictions regarding the moderating role of various procedural features of relief situations. We conclude that our integrated model results in a better understanding of existing evidence on the affective and motivational underpinnings of relief, but that further evidence is needed to come to a more comprehensive evaluation of the viability of IRMO. PMID:25806008

Ultracold Anions for High-Precision Antihydrogen Experiments.

PubMed

Cerchiari, G; Kellerbauer, A; Safronova, M S; Safronova, U I; Yzombard, P

2018-03-30

Experiments with antihydrogen (H[over ¯]) for a study of matter-antimatter symmetry and antimatter gravity require ultracold H[over ¯] to reach ultimate precision. A promising path towards antiatoms much colder than a few kelvin involves the precooling of antiprotons by laser-cooled anions. Because of the weak binding of the valence electron in anions-dominated by polarization and correlation effects-only few candidate systems with suitable transitions exist. We report on a combination of experimental and theoretical studies to fully determine the relevant binding energies, transition rates, and branching ratios of the most promising candidate La^{-}. Using combined transverse and collinear laser spectroscopy, we determined the resonant frequency of the laser cooling transition to be ν=96.592 713(91)  THz and its transition rate to be A=4.90(50)×10^{4}  s^{-1}. Using a novel high-precision theoretical treatment of La^{-} we calculated yet unmeasured energy levels, transition rates, branching ratios, and lifetimes to complement experimental information on the laser cooling cycle of La^{-}. The new data establish the suitability of La^{-} for laser cooling and show that the cooling transition is significantly stronger than suggested by a previous theoretical study.

Examining the construct validity of the Psychopathic Personality Inventory-Revised: preferential correlates of fearless dominance and self-centered impulsivity.

PubMed

Edens, John F; McDermott, Barbara E

2010-03-01

Although the construct of psychopathy is frequently construed as a unitary syndrome, the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996) and its revision, the PPI-R (Lilienfeld & Widows, 2005), are composed of 2 scales, termed Fearless Dominance (FD) and Self-Centered Impulsivity (SCI), which appear to reflect orthogonal dimensions. In this study, we examined the construct validity of the FD and SCI scales of the PPI-R as markers of these constructs with a range of theoretically relevant correlates assessed across multiple domains in a sample of 200 forensic psychiatric inpatients. Results were generally, though not uniformly, consistent with hypothesized relationships: The SCI scale positively and selectively predicted anger and hostility, impulsivity, total psychiatric symptoms, drug abuse or dependence, antisocial behavior, and violence risk, whereas FD predicted anger, depression, anxiety symptoms (negatively), and alcohol abuse or dependence (positively). PsycINFO Database Record (c) 2010 APA, all rights reserved.

Multiscaling and clustering of volatility

NASA Astrophysics Data System (ADS)

Pasquini, Michele; Serva, Maurizio

1999-07-01

The dynamics of prices in stock markets has been studied intensively both experimentally (data analysis) and theoretically (models). Nevertheless, while the distribution of returns of the most important indices is known to be a truncated Lévy, the behaviour of volatility correlations is still poorly understood. What is well known is that absolute returns have memory on a long time range, this phenomenon is known in financial literature as clustering of volatility. In this paper we show that volatility correlations are power laws with a non-unique scaling exponent. This kind of multiscale phenomenology is known to be relevant in fully developed turbulence and in disordered systems and it is pointed out here for the first time for a financial series. In our study we consider the New York Stock Exchange (NYSE) daily index, from January 1966 to June 1998, for a total of 8180 working days.

The theory-practice relationship: reflective skills and theoretical knowledge as key factors in bridging the gap between theory and practice in initial nursing education.

PubMed

Hatlevik, Ida Katrine Riksaasen

2012-04-01

This paper is a report of a correlational study of the relations of nursing students' acquired reflective skills, practical skills and theoretical knowledge on their perception of coherence between theory and practice. Reflection is considered a key factor in bridging the gap between theory and practice. However, it is not evident whether reflective skills are primarily generic in nature or whether they develop from a theoretical knowledge base or the acquisition of practical skills. This study is a secondary analysis of existing data. The data are part of a student survey that was conducted among third-year nursing students in Norway during the spring of 2007. A total of 446 nursing students participated in this study and the response rate was 71%. Structural equation modelling analyses were performed. The results indicate that students' perception of coherence between theory and practice during initial nursing education is directly influenced by reflective skills and theoretical knowledge. The results also reveal that reflective skills have mediating effects and that practical skills have a fully mediated and theoretical knowledge a partially mediated influence on students' perception of coherence. The findings imply that helping students perceive coherence between theory and practice in nursing education, developing students' reflective skills and strengthening the theoretical components of the initial nursing education programme might be beneficial. The results suggest that reflective thinking is not merely a generic skill but rather a skill that depends on the acquisition of relevant professional knowledge and experience. © 2011 Blackwell Publishing Ltd.

Correlation as a Determinant of Configurational Entropy in Supramolecular and Protein Systems

PubMed Central

2015-01-01

For biomolecules in solution, changes in configurational entropy are thought to contribute substantially to the free energies of processes like binding and conformational change. In principle, the configurational entropy can be strongly affected by pairwise and higher-order correlations among conformational degrees of freedom. However, the literature offers mixed perspectives regarding the contributions that changes in correlations make to changes in configurational entropy for such processes. Here we take advantage of powerful techniques for simulation and entropy analysis to carry out rigorous in silico studies of correlation in binding and conformational changes. In particular, we apply information-theoretic expansions of the configurational entropy to well-sampled molecular dynamics simulations of a model host–guest system and the protein bovine pancreatic trypsin inhibitor. The results bear on the interpretation of NMR data, as they indicate that changes in correlation are important determinants of entropy changes for biologically relevant processes and that changes in correlation may either balance or reinforce changes in first-order entropy. The results also highlight the importance of main-chain torsions as contributors to changes in protein configurational entropy. As simulation techniques grow in power, the mathematical techniques used here will offer new opportunities to answer challenging questions about complex molecular systems. PMID:24702693

The physics of flocking: Correlation as a compass from experiments to theory

NASA Astrophysics Data System (ADS)

Cavagna, Andrea; Giardina, Irene; Grigera, Tomás S.

2018-01-01

Collective behavior in biological systems is a complex topic, to say the least. It runs wildly across scales in both space and time, involving taxonomically vastly different organisms, from bacteria and cell clusters, to insect swarms and up to vertebrate groups. It entails concepts as diverse as coordination, emergence, interaction, information, cooperation, decision-making, and synchronization. Amid this jumble, however, we cannot help noting many similarities between collective behavior in biological systems and collective behavior in statistical physics, even though none of these organisms remotely looks like an Ising spin. Such similarities, though somewhat qualitative, are startling, and regard mostly the emergence of global dynamical patterns qualitatively different from individual behavior, and the development of system-level order from local interactions. It is therefore tempting to describe collective behavior in biology within the conceptual framework of statistical physics, in the hope to extend to this new fascinating field at least part of the great predictive power of theoretical physics. In this review we propose that the conceptual cornerstone of this ambitious program be that of correlation. To illustrate this idea we address the case of collective behavior in bird flocks. Two key threads emerge, as two sides of one single story: the presence of scale-free correlations and the dynamical mechanism of information transfer. We discuss first static correlations in starling flocks, in particular the experimental finding of their scale-free nature, the formulation of models that account for this fact using maximum entropy, and the relation of scale-free correlations to information transfer. This is followed by a dynamic treatment of information propagation (propagation of turns across a flock), starting with a discussion of experimental results and following with possible theoretical explanations of those, which require the addition of behavioral inertia to existing theories of flocking. We finish with the definition and analysis of space-time correlations and their relevance to the detection of inertial behavior in the absence of external perturbations.

Vibrationally resolved photoelectron spectroscopy of electronic excited states of DNA bases: application to the ã state of thymine cation.

PubMed

Hochlaf, Majdi; Pan, Yi; Lau, Kai-Chung; Majdi, Youssef; Poisson, Lionel; Garcia, Gustavo A; Nahon, Laurent; Al Mogren, Muneerah Mogren; Schwell, Martin

2015-02-19

For fully understanding the light-molecule interaction dynamics at short time scales, recent theoretical and experimental studies proved the importance of accurate characterizations not only of the ground (D0) but also of the electronic excited states (e.g., D1) of molecules. While ground state investigations are currently straightforward, those of electronic excited states are not. Here, we characterized the à electronic state of ionic thymine (T(+)) DNA base using explicitly correlated coupled cluster ab initio methods and state-of-the-art synchrotron-based electron/ion coincidence techniques. The experimental spectrum is composed of rich and long vibrational progressions corresponding to the population of the low frequency modes of T(+)(Ã). This work challenges previous numerous works carried out on DNA bases using common synchrotron and VUV-based photoelectron spectroscopies. We provide hence a powerful theoretical and experimental framework to study the electronic structure of ionized DNA bases that could be generalized to other medium-sized biologically relevant systems.

An investigation of rotor noise generation by aerodynamic disturbance. [aeroacoustic transfer functions

NASA Technical Reports Server (NTRS)

Whitfield, C. E.

1977-01-01

An open rotor was considered as a process for converting an unsteady velocity inflow into sound radiation. With the aid of crude assumptions, aero-acoustic transfer functions were defined theoretically for both discrete frequency and broad band noise. A study of the validity of these transfer functions yielded results which show good agreement at discrete frequencies though slightly less good for broad band noise. Agreement in both cases holds over three or more decades of the relevant parameters. A rotating hot wire anemometry system consisting of a single hot wire probe mounted in the nose cone of the rotor was used to quantify fluctuations in the airflow onto a single rotor blade for the transfer function results. Further theoretical analysis revealed that the sound field can be expressed in terms of blade-to-blade correlations in the airflow, and results from two probes rotating simultaneously were modelled mathematically and inserted in the theory. Preliminary results snow encouraging agreement with experimental data.

Quantifying predictability in a model with statistical features of the atmosphere

PubMed Central

Kleeman, Richard; Majda, Andrew J.; Timofeyev, Ilya

2002-01-01

The Galerkin truncated inviscid Burgers equation has recently been shown by the authors to be a simple model with many degrees of freedom, with many statistical properties similar to those occurring in dynamical systems relevant to the atmosphere. These properties include long time-correlated, large-scale modes of low frequency variability and short time-correlated “weather modes” at smaller scales. The correlation scaling in the model extends over several decades and may be explained by a simple theory. Here a thorough analysis of the nature of predictability in the idealized system is developed by using a theoretical framework developed by R.K. This analysis is based on a relative entropy functional that has been shown elsewhere by one of the authors to measure the utility of statistical predictions precisely. The analysis is facilitated by the fact that most relevant probability distributions are approximately Gaussian if the initial conditions are assumed to be so. Rather surprisingly this holds for both the equilibrium (climatological) and nonequilibrium (prediction) distributions. We find that in most cases the absolute difference in the first moments of these two distributions (the “signal” component) is the main determinant of predictive utility variations. Contrary to conventional belief in the ensemble prediction area, the dispersion of prediction ensembles is generally of secondary importance in accounting for variations in utility associated with different initial conditions. This conclusion has potentially important implications for practical weather prediction, where traditionally most attention has focused on dispersion and its variability. PMID:12429863

Experimental characterization of pairwise correlations from triple quantum correlated beams generated by cascaded four-wave mixing processes

NASA Astrophysics Data System (ADS)

Wang, Wei; Cao, Leiming; Lou, Yanbo; Du, Jinjian; Jing, Jietai

2018-01-01

We theoretically and experimentally characterize the performance of the pairwise correlations from triple quantum correlated beams based on the cascaded four-wave mixing (FWM) processes. The pairwise correlations between any two of the beams are theoretically calculated and experimentally measured. The experimental and theoretical results are in good agreement. We find that two of the three pairwise correlations can be in the quantum regime. The other pairwise correlation is always in the classical regime. In addition, we also measure the triple-beam correlation which is always in the quantum regime. Such unbalanced and controllable pairwise correlation structures may be taken as advantages in practical quantum communications, for example, hierarchical quantum secret sharing. Our results also open the way for the classification and application of quantum states generated from the cascaded FWM processes.

Predicting differences in the perceived relevance of crime's costs and benefits in a test of rational choice theory.

PubMed

Bouffard, Jeffrey A

2007-08-01

Previous hypothetical scenario tests of rational choice theory have presented all participants with the same set of consequences, implicitly assuming that these consequences would be relevant for each individual. Recent research demonstrates that those researcher-presented consequences do not accurately reflect those considered by study participants and that there is individual variation in the relevance of various consequences. Despite this and some theoretical propositions that such differences should exist, little empirical research has explored the possibility of predicting such variation. This study allows participants to develop their own set of relevant consequences for three hypothetical offenses and examines how several demographic and theoretical variables impact those consequences' relevance. Exploratory results suggest individual factors impact the perceived relevance of several cost and benefit types, even among a relatively homogenous sample of college students. Implications for future tests of rational choice theory, as well as policy implications are discussed.

Relationships between self-determination theory and theory of planned behavior applied to physical activity and exercise behavior in chronic pain.

PubMed

Brooks, Jessica M; Iwanaga, Kanako; Chiu, Chung-Yi; Cotton, Brandi Parker; Deiches, Jon; Morrison, Blaise; Moser, Erin; Chan, Fong

2017-08-01

This study examined the relationships between self-determination theory (SDT) and theory of planned behavior (TpB) applied to physical activity and exercise behavior (PA&E) in people with chronic pain. Two hundred and eleven adults with chronic musculoskeletal pain (28 males and 183 females, age range 18 to 82 years, mean age 43 years) were recruited from online support groups and clinic networks in the United States. Participants completed SDT measures relevant to PA&E on perceived autonomy support, autonomy, competence, and relatedness, as well as TpB measures relevant to PA&E on intention, attitudes, subjective norms, and perceived behavioral control. Correlational techniques and canonical correlation analysis were performed to examine the relationships and variance within and between theoretical dimensions. Overall, the SDT set accounted for 37% of the TpB variance and the TpB set accounted for 32% of the SDT set variance. The results indicate there are statistical similarities and differences between concepts in SDT and TpB models for PA&E. Using both empirical guidance and clinical expertise, researchers and practitioners should attempt to select and integrate non-redundant and complementary components from SDT, TpB, and other related health behavior theories.

Extending extant models of the pathogenesis of borderline personality disorder to childhood borderline personality symptoms: the roles of affective dysfunction, disinhibition, and self- and emotion-regulation deficits.

PubMed

Gratz, Kim L; Tull, Matthew T; Reynolds, Elizabeth K; Bagge, Courtney L; Latzman, Robert D; Daughters, Stacey B; Lejuez, C W

2009-01-01

Although research has been conducted on the course, consequences, and correlates of borderline personality disorder (BPD), little is known about its emergence in childhood, and no studies have examined the extent to which theoretical models of the pathogenesis of BPD in adults are applicable to the correlates of borderline personality symptoms in children. The goal of this study was to examine the interrelationships between two BPD-relevant personality traits (affective dysfunction and disinhibition), self- and emotion-regulation deficits, and childhood borderline personality symptoms among 263 children aged 9 to 13. We predicted that affective dysfunction, disinhibition, and their interaction would be associated with childhood borderline personality symptoms, and that self- and emotion-regulation deficits would mediate these relationships. Results provided support for the roles of both affective dysfunction and disinhibition (in the form of sensation seeking) in childhood borderline personality symptoms, as well as their hypothesized interaction. Further, both self- and emotion-regulation deficits partially mediated the relationship between affective dysfunction and childhood borderline personality symptoms. Finally, results provided evidence of different gender-based pathways to childhood borderline personality symptoms, suggesting that models of BPD among adults are more relevant to understanding the factors associated with borderline personality symptoms among girls than boys.

The relationship between time perspective and self-regulatory processes, abilities and outcomes: a protocol for a meta-analytical review.

PubMed

Baird, Harriet M; Webb, Thomas L; Martin, Jilly; Sirois, Fuschia M

2017-07-05

Both theoretical and empirical evidence suggests that time perspective is likely to influence self-regulatory processes and outcomes. Despite the theoretical and practical significance of such relations, the relationship between time perspective and self-regulatory processes and outcomes across different measures, samples and life domains, including health, has yet to be explored. The proposed review will develop a taxonomy for classifying measures according to the self-regulatory process, ability or outcome that they are likely to reflect. Electronic scientific databases will be searched, along with relevant conference abstract booklets and citation lists. Additionally, a call for unpublished data will be submitted to relevant bodies. To be eligible for inclusion, studies must include a measure of time perspective and a measure of at least one self-regulatory process, ability and/ or outcome. Eligibility will not be restricted by publication date, language, type of sample or setting. The bivariate correlations will be extracted (or calculated) and submitted to a random-effects meta-analysis. The sample-weighted average effect size, heterogeneity, risk of bias and publication bias will be calculated, and the effects of categorical and continuous moderator variables on the effect sizes will be determined. The proposed meta-analysis will synthesise previously conducted research; thus, ethical approval is not required. The findings will be submitted for publication in an international peer-reviewed journal and reported as part of the first author’s PhD thesis. The findings will also be disseminated to the research community and, where appropriate, to other interested parties through presentations at relevant academic and non-academic conferences. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The relationship between time perspective and self-regulatory processes, abilities and outcomes: a protocol for a meta-analytical review

PubMed Central

Baird, Harriet M; Webb, Thomas L; Martin, Jilly; Sirois, Fuschia M

2017-01-01

Introduction Both theoretical and empirical evidence suggests that time perspective is likely to influence self-regulatory processes and outcomes. Despite the theoretical and practical significance of such relations, the relationship between time perspective and self-regulatory processes and outcomes across different measures, samples and life domains, including health, has yet to be explored. Methods and analysis The proposed review will develop a taxonomy for classifying measures according to the self-regulatory process, ability or outcome that they are likely to reflect. Electronic scientific databases will be searched, along with relevant conference abstract booklets and citation lists. Additionally, a call for unpublished data will be submitted to relevant bodies. To be eligible for inclusion, studies must include a measure of time perspective and a measure of at least one self-regulatory process, ability and/ or outcome. Eligibility will not be restricted by publication date, language, type of sample or setting. The bivariate correlations will be extracted (or calculated) and submitted to a random-effects meta-analysis. The sample-weighted average effect size, heterogeneity, risk of bias and publication bias will be calculated, and the effects of categorical and continuous moderator variables on the effect sizes will be determined. Ethics and dissemination The proposed meta-analysis will synthesise previously conducted research; thus, ethical approval is not required. The findings will be submitted for publication in an international peer-reviewed journal and reported as part of the first author’s PhD thesis. The findings will also be disseminated to the research community and, where appropriate, to other interested parties through presentations at relevant academic and non-academic conferences. PMID:28679677

The Dark Matter Crisis: Falsification of the Current Standard Model of Cosmology

NASA Astrophysics Data System (ADS)

Kroupa, P.

2012-06-01

The current standard model of cosmology (SMoC) requires The Dual Dwarf Galaxy Theorem to be true according to which two types of dwarf galaxies must exist: primordial dark-matter (DM) dominated (type A) dwarf galaxies, and tidal-dwarf and ram-pressure-dwarf (type B) galaxies void of DM. Type A dwarfs surround the host approximately spherically, while type B dwarfs are typically correlated in phase-space. Type B dwarfs must exist in any cosmological theory in which galaxies interact. Only one type of dwarf galaxy is observed to exist on the baryonic Tully-Fisher plot and in the radius-mass plane. The Milky Way satellite system forms a vast phase-space-correlated structure that includes globular clusters and stellar and gaseous streams. Other galaxies also have phase-space correlated satellite systems. Therefore, The Dual Dwarf Galaxy Theorem is falsified by observation and dynamically relevant cold or warm DM cannot exist. It is shown that the SMoC is incompatible with a large set of other extragalactic observations. Other theoretical solutions to cosmological observations exist. In particular, alone the empirical mass-discrepancy-acceleration correlation constitutes convincing evidence that galactic-scale dynamics must be Milgromian. Major problems with inflationary big bang cosmologies remain unresolved.

Intelligent control system for continuous technological process of alkylation

NASA Astrophysics Data System (ADS)

Gebel, E. S.; Hakimov, R. A.

2018-01-01

Relevance of intelligent control for complex dynamic objects and processes are shown in this paper. The model of a virtual analyzer based on a neural network is proposed. Comparative analysis of mathematical models implemented in MathLab software showed that the most effective from the point of view of the reproducibility of the result is the model with seven neurons in the hidden layer, the training of which was performed using the method of scaled coupled gradients. Comparison of the data from the laboratory analysis and the theoretical model are showed that the root-mean-square error does not exceed 3.5, and the calculated value of the correlation coefficient corresponds to a "strong" connection between the values.

The mediating effect of self-esteem on the relationship of living environment, anxiety, and depression of underprivileged children: A path analysis in Chinese context.

PubMed

Yin, Xican; Li, Chunkai; Jiang, Shan

2017-11-01

This study aimed to explore the relationships of living environment, self-esteem, anxiety, and depression of children in poverty. A sample of 1314 children (grades 4-9) was collected by a school-based survey in Xiushui city, Mainland China. Structural equation modeling was adopted to analyze the data and verify the hypothesized model. Results showed that living environment was negatively correlated with poor children's anxiety and depression levels, and self-esteem had a mediating effect on the relationship between living environment and the mental health of underprivileged children. Based on these findings, we proposed relevant theoretical and practical implications.

Quantum quenches in the Luttinger model and its close relatives

NASA Astrophysics Data System (ADS)

Cazalilla, M. A.; Chung, Ming-Chiang

2016-06-01

A number of results on quantum quenches in the Luttinger and related models are surveyed with emphasis on post-quench correlations. For the Luttinger model and initial gaussian states, we discuss both sudden and smooth quenches of the interaction and the emergence of a steady state described by a generalized Gibbs ensemble. Comparisons between analytics and numerics, and the question of universality or lack thereof are also discussed. The relevance of the theoretical results to current and future experiments in the fields of ultracold atomic gases and mesoscopic systems of electrons is also briefly touched upon. Wherever possible, our approach is pedagogical and self-contained. This work is dedicated to the memory of our colleague Alejandro Muramatsu.

Construct Validity of the Psychopathic Personality Inventory Two-Factor Model With Offenders

PubMed Central

Patrick, Christopher J.; Poythress, Norman G.; Edens, John F.; Lilienfeld, Scott O.; Benning, Stephen D.

2008-01-01

Much of the research on psychopathy has treated it as a unitary construct operationalized by total scores on one (or more) measures. More recent studies on the Psychopathic Personality Inventory (PPI) suggest the existence of two distinct facets of psychopathy with unique external correlates. Here, the authors report reanalyses of two offender data sets that included scores on the PPI along with various theoretically relevant criterion variables. Consistent with hypotheses, the two PPI factors showed convergent and discriminant relations with criterion measures, many of which would otherwise have been obscured when relying on PPI total scores. These results highlight the importance of examining facets of psychopathy as well as total scores. PMID:16768596

Interpreting neurodynamics: concepts and facts

PubMed Central

Rotter, Stefan

2008-01-01

The dynamics of neuronal systems, briefly neurodynamics, has developed into an attractive and influential research branch within neuroscience. In this paper, we discuss a number of conceptual issues in neurodynamics that are important for an appropriate interpretation and evaluation of its results. We demonstrate their relevance for selected topics of theoretical and empirical work. In particular, we refer to the notions of determinacy and stochasticity in neurodynamics across levels of microscopic, mesoscopic and macroscopic descriptions. The issue of correlations between neural, mental and behavioral states is also addressed in some detail. We propose an informed discussion of conceptual foundations with respect to neurobiological results as a viable step to a fruitful future philosophy of neuroscience. PMID:19003452

Evolutionary dynamics on networks of selectively neutral genotypes: effects of topology and sequence stability.

PubMed

Aguirre, Jacobo; Buldú, Javier M; Manrubia, Susanna C

2009-12-01

Networks of selectively neutral genotypes underlie the evolution of populations of replicators in constant environments. Previous theoretical analysis predicted that such populations will evolve toward highly connected regions of the genome space. We first study the evolution of populations of replicators on simple networks and quantify how the transient time to equilibrium depends on the initial distribution of sequences on the neutral network, on the topological properties of the latter, and on the mutation rate. Second, network neutrality is broken through the introduction of an energy for each sequence. This allows to study the competition between two features (neutrality and energetic stability) relevant for survival and subjected to different selective pressures. In cases where the two features are negatively correlated, the population experiences sudden migrations in the genome space for values of the relevant parameters that we calculate. The numerical study of larger networks indicates that the qualitative behavior to be expected in more realistic cases is already seen in representative examples of small networks.

Evolutionary dynamics on networks of selectively neutral genotypes: Effects of topology and sequence stability

NASA Astrophysics Data System (ADS)

Aguirre, Jacobo; Buldú, Javier M.; Manrubia, Susanna C.

2009-12-01

Networks of selectively neutral genotypes underlie the evolution of populations of replicators in constant environments. Previous theoretical analysis predicted that such populations will evolve toward highly connected regions of the genome space. We first study the evolution of populations of replicators on simple networks and quantify how the transient time to equilibrium depends on the initial distribution of sequences on the neutral network, on the topological properties of the latter, and on the mutation rate. Second, network neutrality is broken through the introduction of an energy for each sequence. This allows to study the competition between two features (neutrality and energetic stability) relevant for survival and subjected to different selective pressures. In cases where the two features are negatively correlated, the population experiences sudden migrations in the genome space for values of the relevant parameters that we calculate. The numerical study of larger networks indicates that the qualitative behavior to be expected in more realistic cases is already seen in representative examples of small networks.

Correlates of resilience in the face of adversity for Korean women immigrating to the US.

PubMed

Lee, Hei-Sung; Brown, Stephen L; Mitchell, Mary M; Schiraldi, Glenn R

2008-10-01

To explore the association between resilience and psychosocial variables of theoretical relevance such as self-esteem, optimism, religiousness, cultural interdependency, and belief in higher education in a population of elderly Korean women and their daughters who experienced great adversity. Surveys were conducted with 200 elderly Korean women and 170 of their daughters in several community locations. Both mothers and daughters experienced great adversities in their lives such as psychological and physical losses from war as well as current and past difficulties with relocation. The mothers' bivariate correlations indicate that self-esteem, optimism, religiousness, and cultural interdependency were significantly correlated with resilience. Length of time in the US, age entering the US, physical and psychological war-related adversities, current relocation difficulties, self-esteem, optimism, cultural interdependency, and belief in education were all significantly associated with daughters' resilience. In linear regression, self-esteem and optimism were significant predictors of resilience in both mothers and daughters. Self-esteem and optimism deserve further attention as psychological factors that may increase the likelihood of developing resilience. Implications of these findings for health professionals are discussed.

Decompression models: review, relevance and validation capabilities.

PubMed

Hugon, J

2014-01-01

For more than a century, several types of mathematical models have been proposed to describe tissue desaturation mechanisms in order to limit decompression sickness. These models are statistically assessed by DCS cases, and, over time, have gradually included bubble formation biophysics. This paper proposes to review this evolution and discuss its limitations. This review is organized around the comparison of decompression model biophysical criteria and theoretical foundations. Then, the DCS-predictive capability was analyzed to assess whether it could be improved by combining different approaches. Most of the operational decompression models have a neo-Haldanian form. Nevertheless, bubble modeling has been gaining popularity, and the circulating bubble amount has become a major output. By merging both views, it seems possible to build a relevant global decompression model that intends to simulate bubble production while predicting DCS risks for all types of exposures and decompression profiles. A statistical approach combining both DCS and bubble detection databases has to be developed to calibrate a global decompression model. Doppler ultrasound and DCS data are essential: i. to make correlation and validation phases reliable; ii. to adjust biophysical criteria to fit at best the observed bubble kinetics; and iii. to build a relevant risk function.

Anomalous scaling of a passive scalar advected by the Navier-Stokes velocity field: two-loop approximation.

PubMed

Adzhemyan, L Ts; Antonov, N V; Honkonen, J; Kim, T L

2005-01-01

The field theoretic renormalization group and operator-product expansion are applied to the model of a passive scalar quantity advected by a non-Gaussian velocity field with finite correlation time. The velocity is governed by the Navier-Stokes equation, subject to an external random stirring force with the correlation function proportional to delta(t- t')k(4-d-2epsilon). It is shown that the scalar field is intermittent already for small epsilon, its structure functions display anomalous scaling behavior, and the corresponding exponents can be systematically calculated as series in epsilon. The practical calculation is accomplished to order epsilon2 (two-loop approximation), including anisotropic sectors. As for the well-known Kraichnan rapid-change model, the anomalous scaling results from the existence in the model of composite fields (operators) with negative scaling dimensions, identified with the anomalous exponents. Thus the mechanism of the origin of anomalous scaling appears similar for the Gaussian model with zero correlation time and the non-Gaussian model with finite correlation time. It should be emphasized that, in contrast to Gaussian velocity ensembles with finite correlation time, the model and the perturbation theory discussed here are manifestly Galilean covariant. The relevance of these results for real passive advection and comparison with the Gaussian models and experiments are briefly discussed.

Neutron-antineutron oscillations: Theoretical status and experimental prospects

DOE PAGES

Phillips, D. G.; Snow, W. M.; Babu, K.; ...

2016-02-01

This paper summarizes the relevant theoretical developments, outlines some ideas to improve experimental searches for free neutron-antineutron oscillations, and suggests avenues for future improvement in the experimental sensitivity.

Validity of a scale of neighbourhood informal social control relevant to pre-schoolers' physical activity: A cross-sectional study.

PubMed

Cerin, Ester; Suen, Yi Nam; Barnett, Anthony; Huang, Wendy Y J; Mellecker, Robin R

2017-12-01

Childhood physical activity (PA) is important for health across the lifespan. Time pre-schoolers spend outdoors, which has been associated with more PA, is likely influenced by parents' perception of neighbourhood informal social control relevant to pre-schoolers' PA, defined as the willingness of neighbours to intervene to ensure social order and a safe community environment for young children's active play. To advance measurement of this construct, we assessed factorial and construct validities of the PA-related neighbourhood informal social control scale for parents of pre-schoolers (PANISC-PP). In 2013-2014, Hong Kong primary caregivers (n=394) of 3-5 year-old children completed a socio-demographic questionnaire, the preliminary version of the PANISC-PP, and self-report measures of theoretical neighbourhood correlates of PA-related neighbourhood informal social control (perceived signs of physical and social disorder, community cohesion, perceived stranger danger, risk of unintentional injury and traffic safety). The fit of the data to an a priori measurement model of the PANISC-PP was examined using confirmatory factor analyses. As the a priori model showed inadequate fit to the data, the factor structure was re-specified based on theoretical considerations. The final measurement models of the PANISC-PP showed acceptable fit to the data and consisted of three correlated latent factors: "General informal supervision", "Civic engagement for the creation of a better neighbourhood environment" and "Educating and assisting neighbourhood children". The internal reliability of the subscales was good (Cronbach's α values 0.82-0.89). Generalised additive mixed models indicated that all subscales were positively associated with community cohesion and scores on the subscale "Educating and assisting neighbourhood children" were related in the expected direction to all indicators of traffic and personal safety, supporting construct validity of the PANISC-PP. This study suggests that the PANISC-PP is a reliable and valid instrument for assessing parents' perceived neighbourhood informal social control related to pre-schoolers' PA.

Global analysis of b → sℓℓ anomalies

NASA Astrophysics Data System (ADS)

Descotes-Genon, Sébastien; Hofer, Lars; Matias, Joaquim; Virto, Javier

2016-06-01

We present a detailed discussion of the current theoretical and experimental situation of the anomaly in the angular distribution of B → K * (→ Kπ) μ + μ -, observed at LHCb in the 1 fb-1 dataset and recently confirmed by the 3 fb-1 dataset. The impact of this data and other recent measurements on b → sℓ + ℓ - transitions ( ℓ = e, μ) is considered. We review the observables of interest, focusing on their theoretical uncertainties and their sensitivity to New Physics, based on an analysis employing the QCD factorisation approach including several sources of hadronic uncertainties (form factors, power corrections, charm-loop effects). We perform fits to New Physics contributions including experimental and theoretical correlations. The solution that we proposed in 2013 to solve the B → K * μ + μ - anomaly, with a contribution {mathcal{C}}_9^{NP}˜eq -1 , is confirmed and reinforced. A wider range of New-Physics scenarios with high significances (between 4 and 5 σ) emerges from the fit, some of them being particularly relevant for model building. More data is needed to discriminate among them conclusively. The inclusion of b → se + e - observables increases the significance of the favoured scenarios under the hypothesis of New Physics breaking lepton flavour universality. Several tests illustrate the robustness of our conclusions.

Precise predictions for V+jets dark matter backgrounds

NASA Astrophysics Data System (ADS)

Lindert, J. M.; Pozzorini, S.; Boughezal, R.; Campbell, J. M.; Denner, A.; Dittmaier, S.; Gehrmann-De Ridder, A.; Gehrmann, T.; Glover, N.; Huss, A.; Kallweit, S.; Maierhöfer, P.; Mangano, M. L.; Morgan, T. A.; Mück, A.; Petriello, F.; Salam, G. P.; Schönherr, M.; Williams, C.

2017-12-01

High-energy jets recoiling against missing transverse energy (MET) are powerful probes of dark matter at the LHC. Searches based on large MET signatures require a precise control of the Z(ν {\\bar{ν }})+ jet background in the signal region. This can be achieved by taking accurate data in control regions dominated by Z(ℓ ^+ℓ ^-)+ jet, W(ℓ ν )+ jet and γ + jet production, and extrapolating to the Z(ν {\\bar{ν }})+ jet background by means of precise theoretical predictions. In this context, recent advances in perturbative calculations open the door to significant sensitivity improvements in dark matter searches. In this spirit, we present a combination of state-of-the-art calculations for all relevant V+ jets processes, including throughout NNLO QCD corrections and NLO electroweak corrections supplemented by Sudakov logarithms at two loops. Predictions at parton level are provided together with detailed recommendations for their usage in experimental analyses based on the reweighting of Monte Carlo samples. Particular attention is devoted to the estimate of theoretical uncertainties in the framework of dark matter searches, where subtle aspects such as correlations across different V+ jet processes play a key role. The anticipated theoretical uncertainty in the Z(ν {\\bar{ν }})+ jet background is at the few percent level up to the TeV range.

Correlated prompt fission data in transport simulations

DOE PAGES

Talou, P.; Vogt, R.; Randrup, J.; ...

2018-01-24

Detailed information on the fission process can be inferred from the observation, modeling and theoretical understanding of prompt fission neutron and γ-ray observables. Beyond simple average quantities, the study of distributions and correlations in prompt data, e.g., multiplicity-dependent neutron and γ-ray spectra, angular distributions of the emitted particles, n -n, n - γ, and γ - γ correlations, can place stringent constraints on fission models and parameters that would otherwise be free to be tuned separately to represent individual fission observables. The FREYA and CGMF codes have been developed to follow the sequential emissions of prompt neutrons and γ raysmore » from the initial excited fission fragments produced right after scission. Both codes implement Monte Carlo techniques to sample initial fission fragment configurations in mass, charge and kinetic energy and sample probabilities of neutron and γ emission at each stage of the decay. This approach naturally leads to using simple but powerful statistical techniques to infer distributions and correlations among many observables and model parameters. The comparison of model calculations with experimental data provides a rich arena for testing various nuclear physics models such as those related to the nuclear structure and level densities of neutron-rich nuclei, the γ-ray strength functions of dipole and quadrupole transitions, the mechanism for dividing the excitation energy between the two nascent fragments near scission, and the mechanisms behind the production of angular momentum in the fragments, etc. Beyond the obvious interest from a fundamental physics point of view, such studies are also important for addressing data needs in various nuclear applications. The inclusion of the FREYA and CGMF codes into the MCNP6.2 and MCNPX - PoliMi transport codes, for instance, provides a new and powerful tool to simulate correlated fission events in neutron transport calculations important in nonproliferation, safeguards, nuclear energy, and defense programs. Here, this review provides an overview of the topic, starting from theoretical considerations of the fission process, with a focus on correlated signatures. It then explores the status of experimental correlated fission data and current efforts to address some of the known shortcomings. Numerical simulations employing the FREYA and CGMF codes are compared to experimental data for a wide range of correlated fission quantities. The inclusion of those codes into the MCNP6.2 and MCNPX - PoliMi transport codes is described and discussed in the context of relevant applications. The accuracy of the model predictions and their sensitivity to model assumptions and input parameters are discussed. Lastly, a series of important experimental and theoretical questions that remain unanswered are presented, suggesting a renewed effort to address these shortcomings.« less

Correlated prompt fission data in transport simulations

NASA Astrophysics Data System (ADS)

Talou, P.; Vogt, R.; Randrup, J.; Rising, M. E.; Pozzi, S. A.; Verbeke, J.; Andrews, M. T.; Clarke, S. D.; Jaffke, P.; Jandel, M.; Kawano, T.; Marcath, M. J.; Meierbachtol, K.; Nakae, L.; Rusev, G.; Sood, A.; Stetcu, I.; Walker, C.

2018-01-01

Detailed information on the fission process can be inferred from the observation, modeling and theoretical understanding of prompt fission neutron and γ-ray observables. Beyond simple average quantities, the study of distributions and correlations in prompt data, e.g., multiplicity-dependent neutron and γ-ray spectra, angular distributions of the emitted particles, n - n, n - γ, and γ - γ correlations, can place stringent constraints on fission models and parameters that would otherwise be free to be tuned separately to represent individual fission observables. The FREYA and CGMF codes have been developed to follow the sequential emissions of prompt neutrons and γ rays from the initial excited fission fragments produced right after scission. Both codes implement Monte Carlo techniques to sample initial fission fragment configurations in mass, charge and kinetic energy and sample probabilities of neutron and γ emission at each stage of the decay. This approach naturally leads to using simple but powerful statistical techniques to infer distributions and correlations among many observables and model parameters. The comparison of model calculations with experimental data provides a rich arena for testing various nuclear physics models such as those related to the nuclear structure and level densities of neutron-rich nuclei, the γ-ray strength functions of dipole and quadrupole transitions, the mechanism for dividing the excitation energy between the two nascent fragments near scission, and the mechanisms behind the production of angular momentum in the fragments, etc. Beyond the obvious interest from a fundamental physics point of view, such studies are also important for addressing data needs in various nuclear applications. The inclusion of the FREYA and CGMF codes into the MCNP6.2 and MCNPX - PoliMi transport codes, for instance, provides a new and powerful tool to simulate correlated fission events in neutron transport calculations important in nonproliferation, safeguards, nuclear energy, and defense programs. This review provides an overview of the topic, starting from theoretical considerations of the fission process, with a focus on correlated signatures. It then explores the status of experimental correlated fission data and current efforts to address some of the known shortcomings. Numerical simulations employing the FREYA and CGMF codes are compared to experimental data for a wide range of correlated fission quantities. The inclusion of those codes into the MCNP6.2 and MCNPX - PoliMi transport codes is described and discussed in the context of relevant applications. The accuracy of the model predictions and their sensitivity to model assumptions and input parameters are discussed. Finally, a series of important experimental and theoretical questions that remain unanswered are presented, suggesting a renewed effort to address these shortcomings.

Correlated prompt fission data in transport simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Talou, P.; Vogt, R.; Randrup, J.

Detailed information on the fission process can be inferred from the observation, modeling and theoretical understanding of prompt fission neutron and γ-ray observables. Beyond simple average quantities, the study of distributions and correlations in prompt data, e.g., multiplicity-dependent neutron and γ-ray spectra, angular distributions of the emitted particles, n -n, n - γ, and γ - γ correlations, can place stringent constraints on fission models and parameters that would otherwise be free to be tuned separately to represent individual fission observables. The FREYA and CGMF codes have been developed to follow the sequential emissions of prompt neutrons and γ raysmore » from the initial excited fission fragments produced right after scission. Both codes implement Monte Carlo techniques to sample initial fission fragment configurations in mass, charge and kinetic energy and sample probabilities of neutron and γ emission at each stage of the decay. This approach naturally leads to using simple but powerful statistical techniques to infer distributions and correlations among many observables and model parameters. The comparison of model calculations with experimental data provides a rich arena for testing various nuclear physics models such as those related to the nuclear structure and level densities of neutron-rich nuclei, the γ-ray strength functions of dipole and quadrupole transitions, the mechanism for dividing the excitation energy between the two nascent fragments near scission, and the mechanisms behind the production of angular momentum in the fragments, etc. Beyond the obvious interest from a fundamental physics point of view, such studies are also important for addressing data needs in various nuclear applications. The inclusion of the FREYA and CGMF codes into the MCNP6.2 and MCNPX - PoliMi transport codes, for instance, provides a new and powerful tool to simulate correlated fission events in neutron transport calculations important in nonproliferation, safeguards, nuclear energy, and defense programs. Here, this review provides an overview of the topic, starting from theoretical considerations of the fission process, with a focus on correlated signatures. It then explores the status of experimental correlated fission data and current efforts to address some of the known shortcomings. Numerical simulations employing the FREYA and CGMF codes are compared to experimental data for a wide range of correlated fission quantities. The inclusion of those codes into the MCNP6.2 and MCNPX - PoliMi transport codes is described and discussed in the context of relevant applications. The accuracy of the model predictions and their sensitivity to model assumptions and input parameters are discussed. Lastly, a series of important experimental and theoretical questions that remain unanswered are presented, suggesting a renewed effort to address these shortcomings.« less

On the Relevance of Bernstein for German-Speaking Switzerland

ERIC Educational Resources Information Center

Bolander, Brook

2009-01-01

This article assesses the relevance of Basil Bernstein for German-speaking Switzerland. It argues that Bernstein is potentially relevant for German-speaking Switzerland in light of contemporary studies which highlight a connection between social background and differential school achievement. After contextualising Bernstein's theoretical outlook…

Interlocking Mechanism between Molecular Gears Attached to Surfaces.

PubMed

Zhao, Rundong; Zhao, Yan-Ling; Qi, Fei; Hermann, Klaus E; Zhang, Rui-Qin; Van Hove, Michel A

2018-03-27

While molecular machines play an increasingly significant role in nanoscience research and applications, there remains a shortage of investigations and understanding of the molecular gear (cogwheel), which is an indispensable and fundamental component to drive a larger correlated molecular machine system. Employing ab initio calculations, we investigate model systems consisting of molecules adsorbed on metal or graphene surfaces, ranging from very simple triple-arm gears such as PF 3 and NH 3 to larger multiarm gears based on carbon rings. We explore in detail the transmission of slow rotational motion from one gear to the next by these relatively simple molecules, so as to isolate and reveal the mechanisms of the relevant intermolecular interactions. Several characteristics of molecular gears are discussed, in particular the flexibility of the arms and the slipping and skipping between interlocking arms of adjacent gears, which differ from familiar macroscopic rigid gears. The underlying theoretical concepts suggest strongly that other analogous structures may also exhibit similar behavior which may inspire future exploration in designing large correlated molecular machines.

Oscillatory frontal theta responses are increased upon bisensory stimulation.

PubMed

Sakowitz, O W; Schürmann, M; Başar, E

2000-05-01

To investigate the functional correlation of oscillatory EEG components with the interaction of sensory modalities following simultaneous audio-visual stimulation. In an experimental study (15 subjects) we compared auditory evoked potentials (AEPs) and visual evoked potentials (VEPs) to bimodal evoked potentials (BEPs; simultaneous auditory and visual stimulation). BEPs were assumed to be brain responses to complex stimuli as a marker for intermodal associative functioning. Frequency domain analysis of these EPs showed marked theta-range components in response to bimodal stimulation. These theta components could not be explained by linear addition of the unimodal responses in the time domain. Considering topography the increased theta-response showed a remarkable frontality in proximity to multimodal association cortices. Referring to methodology we try to demonstrate that, even if various behavioral correlates of brain oscillations exist, common patterns can be extracted by means of a systems-theoretical approach. Serving as an example of functionally relevant brain oscillations, theta responses could be interpreted as an indicator of associative information processing.

Positive Attitudes towards Technologies and facets of Well-being in Older Adults.

PubMed

Zambianchi, Manuela; Carelli, Maria Grazia

2018-03-01

The current study investigates the relevance of positive attitudes toward Internet technologies for psychological well-being and social well-being in old age. A sample of 245 elderly people ( Mean age = 70; SD =9.1) filled in the Psychological Well-Being Questionnaire, the Social Well-Being Questionnaire, and Attitudes Toward Technologies Questionnaire (ATTQ). Favorable attitudes toward Internet technologies showed positive correlations with overall social well-being and all its components with the exception of social acceptance. Positive correlations with overall psychological well-being and two of its components, namely, personal growth and purpose in life, were also found. Two hierarchical multiple regression models underscored that positive attitudes toward Internet technologies constitute the most important predictor of social well-being, and it appears to be a significant predictor for psychological well-being as well. Results are discussed and integrated into the Positive Technology theoretical framework that sustains the value of technological resources for improving the quality of personal experience and well-being.

A non-ideal MHD model for structure formation

NASA Astrophysics Data System (ADS)

Karmakar, Pralay Kumar; Sarma, Pankaj

2018-02-01

The evolutionary initiation dynamics of triggered planetary structure formation is indeed a complex process yet to be well understood. We herein develop a theoretical classical model to see the gravitational fragmentation kinetics of the viscoelastic non-ideal magneto-hydro-dynamic (MHD) fabric. The inhomogeneous planetary disk is primarily composed of heavier dust grains (strongly correlated) together with relatively lighter electrons, ions and neutrals (weakly correlated) in a mean-fluidic approximation. A normal harmonic mode analysis results in a quadratic dispersion relation of a unique shape. It is demonstrated that the growth rate of the MHD fluctuations (magnetosonic) contributing to the planet formation rate, apart from the wave vector and its projection orientation, has a pure explicit dependency on the viscoelastic parameters. The analysis specifically shows that the effective generalized viscosity (χ) , viscoelastic relaxation time (τm) , and K-orientation (θ) play as destabilizing agencies against the non-local gravitational disk collapse. The relevancy is briefly indicated in the real astronomical context of bounded planetary structure formation and evolution.

Quantum Synchronization of three-level atoms

NASA Astrophysics Data System (ADS)

He, Peiru; Rey, Ana Maria; Holland, Murray

2015-05-01

Recent studies show that quantum synchronization, the spontaneous alignment of the quantum phase between different oscillators, can be used to build superradiant lasers with ultranarrow linewidth. We theoretically investigate the effect of quantum synchronization on many coupled three-level atoms where there are richer phase diagrams than the standard two-level system. This three-level model allows two-color ultranarrow coherent light to be produced where more than one phase must be simultaneously synchronized. Of particular interest, we study the V-type geometry that is relevant to current 87 Sr experiments in JILA. As well as the synchronization phenomenon, we explore other quantum effects such as photon correlations and squeezing. This work is supported by the DARPA QuASAR program, the NSF, and NIST.

Scanning tunneling spectroscopy study of the proximity effect in a disordered two-dimensional metal.

PubMed

Serrier-Garcia, L; Cuevas, J C; Cren, T; Brun, C; Cherkez, V; Debontridder, F; Fokin, D; Bergeret, F S; Roditchev, D

2013-04-12

The proximity effect between a superconductor and a highly diffusive two-dimensional metal is revealed in a scanning tunneling spectroscopy experiment. The in situ elaborated samples consist of superconducting single crystalline Pb islands interconnected by a nonsuperconducting atomically thin disordered Pb wetting layer. In the vicinity of each superconducting island the wetting layer acquires specific tunneling characteristics which reflect the interplay between the proximity-induced superconductivity and the inherent electron correlations of this ultimate diffusive two-dimensional metal. The observed spatial evolution of the tunneling spectra is accounted for theoretically by combining the Usadel equations with the theory of dynamical Coulomb blockade; the relevant length and energy scales are extracted and found in agreement with available experimental data.

Substitutional doping of carbon nanotubes with heteroatoms and their chemical applications.

PubMed

Zhang, Yexin; Zhang, Jian; Su, Dang Sheng

2014-05-01

The electronic properties of carbon nanotubes (CNTs) can be tuned by substitutional doping with heteroatoms (mainly B and N) to expand the applications of CNTs. Based on the comprehensive understanding of the substitutional doping of CNTs, it should be possible to deliberately design doped CNTs for specific purposes. Thus, relevant experimental and theoretical works are reviewed herein in an attempt to correlate the synthetic methods, electronic properties, and applications of heteroatom-doped CNTs. The distribution and arrangement of heteroatoms in the graphitic lattice of CNTs can be modulated through the choice of synthetic conditions, which would further lead to different electronic properties of CNTs for their chemical applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Extending Extant Models of the Pathogenesis of Borderline Personality Disorder to Childhood Borderline Personality Symptoms: The Roles of Affective Dysfunction, Disinhibition, and Self-and Emotion-Regulation Deficits

PubMed Central

Gratz, Kim L.; Tull, Matthew T.; Reynolds, Elizabeth K.; Bagge, Courtney L.; Latzman, Robert D.; Daughters, Stacey B.; Lejuez, C. W.

2010-01-01

Although research has been conducted on the course, consequences, and correlates of borderline personality disorder (BPD), little is known about its emergence in childhood, and no studies have examined the extent to which theoretical models of the pathogenesis of BPD in adults are applicable to the correlates of borderline personality symptoms in children. The goal of this study was to examine the interrelationships between two BPD-relevant personality traits (affective dysfunction and disinhibition), self- and emotion regulation deficits, and childhood borderline personality symptoms among 263 children aged 9 to 13. We predicted that affective dysfunction, disinhibition, and their interaction would be associated with childhood borderline personality symptoms, and that self- and emotion-regulation deficits would mediate these relationships. Results provided support for the roles of both affective dysfunction and disinhibition (in the form of sensation seeking) in childhood borderline personality symptoms, as well as their hypothesized interaction. Further, both self- and emotion-regulation deficits partially mediated the relationship between affective dysfunction and childhood borderline personality symptoms. Finally, results provided evidence of different gender-based pathways to childhood borderline personality symptoms, suggesting that models of BPD among adults are more relevant to understanding the factors associated with borderline personality symptoms among girls than boys. PMID:19825268

Attention to pain! A neurocognitive perspective on attentional modulation of pain in neuroimaging studies.

PubMed

Torta, D M; Legrain, V; Mouraux, A; Valentini, E

2017-04-01

Several studies have used neuroimaging techniques to investigate brain correlates of the attentional modulation of pain. Although these studies have advanced the knowledge in the field, important confounding factors such as imprecise theoretical definitions of attention, incomplete operationalization of the construct under exam, and limitations of techniques relying on measuring regional changes in cerebral blood flow have hampered the potential relevance of the conclusions. Here, we first provide an overview of the major theories of attention and of attention in the study of pain to bridge theory and experimental results. We conclude that load and motivational/affective theories are particularly relevant to study the attentional modulation of pain and should be carefully integrated in functional neuroimaging studies. Then, we summarize previous findings and discuss the possible neural correlates of the attentional modulation of pain. We discuss whether classical functional neuroimaging techniques are suitable to measure the effect of a fluctuating process like attention, and in which circumstances functional neuroimaging can be reliably used to measure the attentional modulation of pain. Finally, we argue that the analysis of brain networks and spontaneous oscillations may be a crucial future development in the study of attentional modulation of pain, and why the interplay between attention and pain, as examined so far, may rely on neural mechanisms shared with other sensory modalities. Copyright © 2017 Elsevier Ltd. All rights reserved.

A framework for the design and development of physical employment tests and standards.

PubMed

Payne, W; Harvey, J

2010-07-01

Because operational tasks in the uniformed services (military, police, fire and emergency services) are physically demanding and incur the risk of injury, employment policy in these services is usually competency based and predicated on objective physical employment standards (PESs) based on physical employment tests (PETs). In this paper, a comprehensive framework for the design of PETs and PESs is presented. Three broad approaches to physical employment testing are described and compared: generic predictive testing; task-related predictive testing; task simulation testing. Techniques for the selection of a set of tests with good coverage of job requirements, including job task analysis, physical demands analysis and correlation analysis, are discussed. Regarding individual PETs, theoretical considerations including measurability, discriminating power, reliability and validity, and practical considerations, including development of protocols, resource requirements, administrative issues and safety, are considered. With regard to the setting of PESs, criterion referencing and norm referencing are discussed. STATEMENT OF RELEVANCE: This paper presents an integrated and coherent framework for the development of PESs and hence provides a much needed theoretically based but practically oriented guide for organisations seeking to establish valid and defensible PESs.

Disordered eating among Asian American college women: A racially expanded model of objectification theory.

PubMed

Cheng, Hsiu-Lan; Tran, Alisia G T T; Miyake, Elisa R; Kim, Helen Youngju

2017-03-01

Objectification theory has been applied to understand disordered eating among college women. A recent extension of objectification theory (Moradi, 2010) conceptualizes racism as a socialization experience that shapes women of color's objectification experiences, yet limited research has examined this theoretical assertion. The present study proposed and examined a racially expanded model of objectification theory that postulated perceived racial discrimination, perpetual foreigner racism, and racial/ethnic teasing as correlates of Asian American college women's (N = 516) self-objectification processes and eating disorder symptomatology. Perceived racial discrimination, perpetual foreigner racism, and racial/ethnic teasing were indirectly associated with eating disordered symptomatology through self-objectification processes of internalization of media ideals of beauty (media internalization), body surveillance, and body shame. Results support the inclusion of racial stressors as contexts of objectification for Asian American women. The present findings also underscore perceived racial discrimination, racial/ethnic teasing, and perpetual foreigner racism as group-specific risk factors with major theoretical, empirical, and clinical relevance to eating disorder research and treatment with Asian American college women. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A Novel Information-Theoretic Approach for Variable Clustering and Predictive Modeling Using Dirichlet Process Mixtures

PubMed Central

Chen, Yun; Yang, Hui

2016-01-01

In the era of big data, there are increasing interests on clustering variables for the minimization of data redundancy and the maximization of variable relevancy. Existing clustering methods, however, depend on nontrivial assumptions about the data structure. Note that nonlinear interdependence among variables poses significant challenges on the traditional framework of predictive modeling. In the present work, we reformulate the problem of variable clustering from an information theoretic perspective that does not require the assumption of data structure for the identification of nonlinear interdependence among variables. Specifically, we propose the use of mutual information to characterize and measure nonlinear correlation structures among variables. Further, we develop Dirichlet process (DP) models to cluster variables based on the mutual-information measures among variables. Finally, orthonormalized variables in each cluster are integrated with group elastic-net model to improve the performance of predictive modeling. Both simulation and real-world case studies showed that the proposed methodology not only effectively reveals the nonlinear interdependence structures among variables but also outperforms traditional variable clustering algorithms such as hierarchical clustering. PMID:27966581

Contact stiffness of regularly patterned multi-asperity interfaces

NASA Astrophysics Data System (ADS)

Li, Shen; Yao, Quanzhou; Li, Qunyang; Feng, Xi-Qiao; Gao, Huajian

2018-02-01

Contact stiffness is a fundamental mechanical index of solid surfaces and relevant to a wide range of applications. Although the correlation between contact stiffness, contact size and load has long been explored for single-asperity contacts, our understanding of the contact stiffness of rough interfaces is less clear. In this work, the contact stiffness of hexagonally patterned multi-asperity interfaces is studied using a discrete asperity model. We confirm that the elastic interaction among asperities is critical in determining the mechanical behavior of rough contact interfaces. More importantly, in contrast to the common wisdom that the interplay of asperities is solely dictated by the inter-asperity spacing, we show that the number of asperities in contact (or equivalently, the apparent size of contact) also plays an indispensable role. Based on the theoretical analysis, we propose a new parameter for gauging the closeness of asperities. Our theoretical model is validated by a set of experiments. To facilitate the application of the discrete asperity model, we present a general equation for contact stiffness estimation of regularly rough interfaces, which is further proved to be applicable for interfaces with single-scale random roughness.

A Novel Information-Theoretic Approach for Variable Clustering and Predictive Modeling Using Dirichlet Process Mixtures.

PubMed

Chen, Yun; Yang, Hui

2016-12-14

In the era of big data, there are increasing interests on clustering variables for the minimization of data redundancy and the maximization of variable relevancy. Existing clustering methods, however, depend on nontrivial assumptions about the data structure. Note that nonlinear interdependence among variables poses significant challenges on the traditional framework of predictive modeling. In the present work, we reformulate the problem of variable clustering from an information theoretic perspective that does not require the assumption of data structure for the identification of nonlinear interdependence among variables. Specifically, we propose the use of mutual information to characterize and measure nonlinear correlation structures among variables. Further, we develop Dirichlet process (DP) models to cluster variables based on the mutual-information measures among variables. Finally, orthonormalized variables in each cluster are integrated with group elastic-net model to improve the performance of predictive modeling. Both simulation and real-world case studies showed that the proposed methodology not only effectively reveals the nonlinear interdependence structures among variables but also outperforms traditional variable clustering algorithms such as hierarchical clustering.

The structural, connectomic and network covariance of the human brain.

PubMed

Irimia, Andrei; Van Horn, John D

2013-02-01

Though it is widely appreciated that complex structural, functional and morphological relationships exist between distinct areas of the human cerebral cortex, the extent to which such relationships coincide remains insufficiently appreciated. Here we determine the extent to which correlations between brain regions are modulated by either structural, connectomic or network-theoretic properties using a structural neuroimaging data set of magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) volumes acquired from N=110 healthy human adults. To identify the linear relationships between all available pairs of regions, we use canonical correlation analysis to test whether a statistically significant correlation exists between each pair of cortical parcels as quantified via structural, connectomic or network-theoretic measures. In addition to this, we investigate (1) how each group of canonical variables (whether structural, connectomic or network-theoretic) contributes to the overall correlation and, additionally, (2) whether each individual variable makes a significant contribution to the test of the omnibus null hypothesis according to which no correlation between regions exists across subjects. We find that, although region-to-region correlations are extensively modulated by structural and connectomic measures, there are appreciable differences in how these two groups of measures drive inter-regional correlation patterns. Additionally, our results indicate that the network-theoretic properties of the cortex are strong modulators of region-to-region covariance. Our findings are useful for understanding the structural and connectomic relationship between various parts of the brain, and can inform theoretical and computational models of cortical information processing. Published by Elsevier Inc.

Towards Culturally Relevant Classroom Science: A Theoretical Framework Focusing on Traditional Plant Healing

ERIC Educational Resources Information Center

Mpofu, Vongai; Otulaja, Femi S.; Mushayikwa, Emmanuel

2014-01-01

A theoretical framework is an important component of a research study. It grounds the study and guides the methodological design. It also forms a reference point for the interpretation of the research findings. This paper conceptually examines the process of constructing a multi-focal theoretical lens for guiding studies that aim to accommodate…

Factors Influencing the Use of Learning Management System in Saudi Arabian Higher Education: A Theoretical Framework

ERIC Educational Resources Information Center

Asiri, Mohammed J. Sherbib; Mahmud, Rosnaini bt; Bakar, Kamariah Abu; Ayub, Ahmad Fauzi bin Mohd

2012-01-01

The purpose of this paper is to present the theoretical framework underlying a research on factors that influence utilization of the Jusur Learning Management System (Jusur LMS) in Saudi Arabian public universities. Development of the theoretical framework was done based on library research approach. Initially, the existing literature relevant to…

Analysis of Implicit Uncertain Systems. Part 1: Theoretical Framework

DTIC Science & Technology

1994-12-07

Analysis of Implicit Uncertain Systems Part I: Theoretical Framework Fernando Paganini * John Doyle 1 December 7, 1994 Abst rac t This paper...Analysis of Implicit Uncertain Systems Part I: Theoretical Framework 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...model and a number of constraints relevant to the analysis problem under consideration. In Part I of this paper we propose a theoretical framework which

Development and Validation of the Five-by-Five Resilience Scale.

PubMed

DeSimone, Justin A; Harms, P D; Vanhove, Adam J; Herian, Mitchel N

2017-09-01

This article introduces a new measure of resilience and five related protective factors. The Five-by-Five Resilience Scale (5×5RS) is developed on the basis of theoretical and empirical considerations. Two samples ( N = 475 and N = 613) are used to assess the factor structure, reliability, convergent validity, and criterion-related validity of the 5×5RS. Confirmatory factor analysis supports a bifactor model. The 5×5RS demonstrates adequate internal consistency as evidenced by Cronbach's alpha and empirical reliability estimates. The 5×5RS correlates positively with the Connor-Davidson Resilience Scale (CD-RISC), a commonly used measure of resilience. The 5×5RS exhibits similar criterion-related validity to the CD-RISC as evidenced by positive correlations with satisfaction with life, meaning in life, and secure attachment style as well as negative correlations with rumination and anxious or avoidant attachment styles. 5×5RS scores are positively correlated with healthy behaviors such as exercise and negatively correlated with sleep difficulty and symptomology of anxiety and depression. The 5×5RS incrementally explains variance in some criteria above and beyond the CD-RISC. Item responses are modeled using the graded response model. Information estimates demonstrate the ability of the 5×5RS to assess individuals within at least one standard deviation of the mean on relevant latent traits.

Organizational Socialization: A Social Learning Interpretation

DTIC Science & Technology

1982-02-01

approaches to socialization, they lack a clear theoretical basis for understanding and application. This paper proposes a social learning theoretical ... framework . Particular attention is given to the relevancy that modeling and self-control can have for organizational socialization. Specific examples of

Laser speckle based digital optical methods in structural mechanics: A review

NASA Astrophysics Data System (ADS)

De la Torre, I. Manuel; Hernández Montes, María del Socorro; Flores-Moreno, J. Mauricio; Santoyo, Fernando Mendoza

2016-12-01

Laser Speckle Correlation, Electronic Speckle Pattern Interferometry and Digital Holographic interferometry have evolved for decades to become relevant techniques in many fields of today's wide spectrum of knowledge and disciplines. Indeed, with today's advances in optics, photonics, electronics and computing there are many important applications for them and strictly speaking there are an almost infinite number of applications that one can think of, as they are non-contact optical techniques that can be used to measure mechanical parameters ranging from a few microns to hundreds of nanometers. In this review we will explore and discuss some relevant applications in structural mechanics in the fields of materials in engineering, biomedical and art preservation and restoration. This work will take the reader from a succinct historical account on the development of these techniques, followed by a brief theoretical description for each one that will then facilitate the introduction of the results chosen as the key applications, ending the review with the conclusions. From the myriad of papers now available in the web, we will only present those that we believe are the most illustrative applications within three lustrum, 2000 to 2015, all set to give a frame that place these optical techniques as mature technologies with an absolute relevance to conduct metrology in many fields.

Making Learning Personally Meaningful: A New Framework for Relevance Research

ERIC Educational Resources Information Center

Priniski, Stacy J.; Hecht, Cameron A.; Harackiewicz, Judith M.

2018-01-01

Personal relevance goes by many names in the motivation literature, stemming from a number of theoretical frameworks. Currently these lines of research are being conducted in parallel with little synthesis across them, perhaps because there is no unifying definition of the relevance construct within which this research can be situated. In this…

One-year test-retest reliability of intrinsic connectivity network fMRI in older adults

PubMed Central

Guo, Cong C.; Kurth, Florian; Zhou, Juan; Mayer, Emeran A.; Eickhoff, Simon B; Kramer, Joel H.; Seeley, William W.

2014-01-01

“Resting-state” or task-free fMRI can assess intrinsic connectivity network (ICN) integrity in health and disease, suggesting a potential for use of these methods as disease-monitoring biomarkers. Numerous analytical options are available, including model-driven ROI-based correlation analysis and model-free, independent component analysis (ICA). High test-retest reliability will be a necessary feature of a successful ICN biomarker, yet available reliability data remains limited. Here, we examined ICN fMRI test-retest reliability in 24 healthy older subjects scanned roughly one year apart. We focused on the salience network, a disease-relevant ICN not previously subjected to reliability analysis. Most ICN analytical methods proved reliable (intraclass coefficients > 0.4) and could be further improved by wavelet analysis. Seed-based ROI correlation analysis showed high map-wise reliability, whereas graph theoretical measures and temporal concatenation group ICA produced the most reliable individual unit-wise outcomes. Including global signal regression in ROI-based correlation analyses reduced reliability. Our study provides a direct comparison between the most commonly used ICN fMRI methods and potential guidelines for measuring intrinsic connectivity in aging control and patient populations over time. PMID:22446491

Quantum Discord Determines the Interferometric Power of Quantum States

NASA Astrophysics Data System (ADS)

Girolami, Davide; Souza, Alexandre M.; Giovannetti, Vittorio; Tufarelli, Tommaso; Filgueiras, Jefferson G.; Sarthour, Roberto S.; Soares-Pinto, Diogo O.; Oliveira, Ivan S.; Adesso, Gerardo

2014-05-01

Quantum metrology exploits quantum mechanical laws to improve the precision in estimating technologically relevant parameters such as phase, frequency, or magnetic fields. Probe states are usually tailored to the particular dynamics whose parameters are being estimated. Here we consider a novel framework where quantum estimation is performed in an interferometric configuration, using bipartite probe states prepared when only the spectrum of the generating Hamiltonian is known. We introduce a figure of merit for the scheme, given by the worst-case precision over all suitable Hamiltonians, and prove that it amounts exactly to a computable measure of discord-type quantum correlations for the input probe. We complement our theoretical results with a metrology experiment, realized in a highly controllable room-temperature nuclear magnetic resonance setup, which provides a proof-of-concept demonstration for the usefulness of discord in sensing applications. Discordant probes are shown to guarantee a nonzero phase sensitivity for all the chosen generating Hamiltonians, while classically correlated probes are unable to accomplish the estimation in a worst-case setting. This work establishes a rigorous and direct operational interpretation for general quantum correlations, shedding light on their potential for quantum technology.

Coding stimulus amplitude by correlated neural activity

NASA Astrophysics Data System (ADS)

Metzen, Michael G.; Ávila-Åkerberg, Oscar; Chacron, Maurice J.

2015-04-01

While correlated activity is observed ubiquitously in the brain, its role in neural coding has remained controversial. Recent experimental results have demonstrated that correlated but not single-neuron activity can encode the detailed time course of the instantaneous amplitude (i.e., envelope) of a stimulus. These have furthermore demonstrated that such coding required and was optimal for a nonzero level of neural variability. However, a theoretical understanding of these results is still lacking. Here we provide a comprehensive theoretical framework explaining these experimental findings. Specifically, we use linear response theory to derive an expression relating the correlation coefficient to the instantaneous stimulus amplitude, which takes into account key single-neuron properties such as firing rate and variability as quantified by the coefficient of variation. The theoretical prediction was in excellent agreement with numerical simulations of various integrate-and-fire type neuron models for various parameter values. Further, we demonstrate a form of stochastic resonance as optimal coding of stimulus variance by correlated activity occurs for a nonzero value of noise intensity. Thus, our results provide a theoretical explanation of the phenomenon by which correlated but not single-neuron activity can code for stimulus amplitude and how key single-neuron properties such as firing rate and variability influence such coding. Correlation coding by correlated but not single-neuron activity is thus predicted to be a ubiquitous feature of sensory processing for neurons responding to weak input.

Raman and Fourier Transform Infrared (FT-IR) Mineral to Matrix Ratios Correlate with Physical Chemical Properties of Model Compounds and Native Bone Tissue.

PubMed

Taylor, Erik A; Lloyd, Ashley A; Salazar-Lara, Carolina; Donnelly, Eve

2017-10-01

Raman and Fourier transform infrared (FT-IR) spectroscopic imaging techniques can be used to characterize bone composition. In this study, our objective was to validate the Raman mineral:matrix ratios (ν 1 PO 4 :amide III, ν 1 PO 4 :amide I, ν 1 PO 4 :Proline + hydroxyproline, ν 1 PO 4 :Phenylalanine, ν 1 PO 4 :δ CH 2 peak area ratios) by correlating them to ash fraction and the IR mineral:matrix ratio (ν 3 PO 4 :amide I peak area ratio) in chemical standards and native bone tissue. Chemical standards consisting of varying ratios of synthetic hydroxyapatite (HA) and collagen, as well as bone tissue from humans, sheep, and mice, were characterized with confocal Raman spectroscopy and FT-IR spectroscopy and gravimetric analysis. Raman and IR mineral:matrix ratio values from chemical standards increased reciprocally with ash fraction (Raman ν 1 PO 4 /Amide III: P < 0.01, R 2  = 0.966; Raman ν 1 PO 4 /Amide I: P < 0.01, R 2  = 0.919; Raman ν 1 PO 4 /Proline + Hydroxyproline: P < 0.01, R 2  = 0.976; Raman ν 1 PO 4 /Phenylalanine: P < 0.01, R 2  = 0.911; Raman ν 1 PO 4 /δ CH 2 : P < 0.01, R 2  = 0.894; IR P < 0.01, R 2  = 0.91). Fourier transform infrared mineral:matrix ratio values from native bone tissue were also similar to theoretical mineral:matrix ratio values for a given ash fraction. Raman and IR mineral:matrix ratio values were strongly correlated ( P < 0.01, R 2  = 0.82). These results were confirmed by calculating the mineral:matrix ratio for theoretical IR spectra, developed by applying the Beer-Lambert law to calculate the relative extinction coefficients of HA and collagen over the same range of wavenumbers (800-1800 cm -1 ). The results confirm that the Raman mineral:matrix bone composition parameter correlates strongly to ash fraction and to its IR counterpart. Finally, the mineral:matrix ratio values of the native bone tissue are similar to those of both chemical standards and theoretical values, confirming the biological relevance of the chemical standards and the characterization techniques.

Environmental education curriculum evaluation questionnaire: A reliability and validity study

NASA Astrophysics Data System (ADS)

Minner, Daphne Diane

The intention of this research project was to bridge the gap between social science research and application to the environmental domain through the development of a theoretically derived instrument designed to give educators a template by which to evaluate environmental education curricula. The theoretical base for instrument development was provided by several developmental theories such as Piaget's theory of cognitive development, Developmental Systems Theory, Life-span Perspective, as well as curriculum research within the area of environmental education. This theoretical base fueled the generation of a list of components which were then translated into a questionnaire with specific questions relevant to the environmental education domain. The specific research question for this project is: Can a valid assessment instrument based largely on human development and education theory be developed that reliably discriminates high, moderate, and low quality in environmental education curricula? The types of analyses conducted to answer this question were interrater reliability (percent agreement, Cohen's Kappa coefficient, Pearson's Product-Moment correlation coefficient), test-retest reliability (percent agreement, correlation), and criterion-related validity (correlation). Face validity and content validity were also assessed through thorough reviews. Overall results indicate that 29% of the questions on the questionnaire demonstrated a high level of interrater reliability and 43% of the questions demonstrated a moderate level of interrater reliability. Seventy-one percent of the questions demonstrated a high test-retest reliability and 5% a moderate level. Fifty-five percent of the questions on the questionnaire were reliable (high or moderate) both across time and raters. Only eight questions (8%) did not show either interrater or test-retest reliability. The global overall rating of high, medium, or low quality was reliable across both coders and time, indicating that the questionnaire can discriminate differences in quality of environmental education curricula. Of the 35 curricula evaluated, 6 were high quality, 14 were medium quality and 15 were low quality. The criterion-related validity of the instrument is at current time unable to be established due to the lack of comparable measures or a concretely usable set of multidisciplinary standards. Face and content validity were sufficiently demonstrated.

Theoretical development and first-principles analysis of strongly correlated systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Chen

A variety of quantum many-body methods have been developed for studying the strongly correlated electron systems. We have also proposed a computationally efficient and accurate approach, named the correlation matrix renormalization (CMR) method, to address the challenges. The initial implementation of the CMR method is designed for molecules which have theoretical advantages, including small size of system, manifest mechanism and strongly correlation effect such as bond breaking process. The theoretic development and benchmark tests of the CMR method are included in this thesis. Meanwhile, ground state total energy is the most important property of electronic calculations. We also investigated anmore » alternative approach to calculate the total energy, and extended this method for magnetic anisotropy energy (MAE) of ferromagnetic materials. In addition, another theoretical tool, dynamical mean- field theory (DMFT) on top of the DFT , has also been used in electronic structure calculations for an Iridium oxide to study the phase transition, which results from an interplay of the d electrons' internal degrees of freedom.« less

Determinants of Thailand household healthcare expenditure: the relevance of permanent resources and other correlates.

PubMed

Okunade, Albert A; Suraratdecha, Chutima; Benson, David A

2010-03-01

Several papers in the leading health economics journals modeled the determinants of healthcare expenditure using household survey or family budgets data of developed countries. Past work largely used self-reported current income as the core determinant, whereas the theoretically correct concept of household resource constraint is permanent or long-run income (á lá Milton Friedman). This paper strives to rectify the theoretical oversight of using current income by augmenting the model with household asset. Using longitudinal data, we constructed 'wealth index' as a distinct covariate to capture the households' tendency to liquidate assets when defraying necessary healthcare liabilities after exhausting cash incomes. (Current income and assets together capture the household expanded resource base). Using 98 632 household observations from Thailand Socio-Economic Surveys (1994-2000 biennial data cycles) we found, using a double-hurdle model with dependent errors, that out-of-pocket healthcare spending behaves as a technical necessity across income quintiles and household sizes. Pre-1997 economic shock income elasticities are smaller than the post-shock estimates across income quintiles for large and small households. Proximity to death, median age, and assets are also among other significant determinants. Our novel findings extend the theoretical consistency of a multi-level decision model in household healthcare expenditure in the developing Asian country context. (c) 2009 John Wiley & Sons, Ltd.

Information-Theoretic Metrics for Visualizing Gene-Environment Interactions

PubMed Central

Chanda, Pritam ; Zhang, Aidong ; Brazeau, Daniel ; Sucheston, Lara ; Freudenheim, Jo L. ; Ambrosone, Christine ; Ramanathan, Murali 

2007-01-01

The purpose of our work was to develop heuristics for visualizing and interpreting gene-environment interactions (GEIs) and to assess the dependence of candidate visualization metrics on biological and study-design factors. Two information-theoretic metrics, the k-way interaction information (KWII) and the total correlation information (TCI), were investigated. The effectiveness of the KWII and TCI to detect GEIs in a diverse range of simulated data sets and a Crohn disease data set was assessed. The sensitivity of the KWII and TCI spectra to biological and study-design variables was determined. Head-to-head comparisons with the relevance-chain, multifactor dimensionality reduction, and the pedigree disequilibrium test (PDT) methods were obtained. The KWII and TCI spectra, which are graphical summaries of the KWII and TCI for each subset of environmental and genotype variables, were found to detect each known GEI in the simulated data sets. The patterns in the KWII and TCI spectra were informative for factors such as case-control misassignment, locus heterogeneity, allele frequencies, and linkage disequilibrium. The KWII and TCI spectra were found to have excellent sensitivity for identifying the key disease-associated genetic variations in the Crohn disease data set. In head-to-head comparisons with the relevance-chain, multifactor dimensionality reduction, and PDT methods, the results from visual interpretation of the KWII and TCI spectra performed satisfactorily. The KWII and TCI are promising metrics for visualizing GEIs. They are capable of detecting interactions among numerous single-nucleotide polymorphisms and environmental variables for a diverse range of GEI models. PMID:17924337

Assessing Relevance of External Cognitive Measures.

PubMed

Cairó, Osvaldo

2017-01-01

The arrival of modern brain imaging technologies has provided new opportunities for examining the biological essence of human intelligence as well as the relationship between brain size and cognition. Thanks to these advances, we can now state that the relationship between brain size and intelligence has never been well understood. This view is supported by findings showing that cognition is correlated more with brain tissues than sheer brain size. The complexity of cellular and molecular organization of neural connections actually determines the computational capacity of the brain. In this review article, we determine that while genotypes are responsible for defining the theoretical limits of intelligence, what is primarily responsible for determining whether those limits are reached or exceeded is experience (environmental influence). Therefore, we contend that the gene-environment interplay defines the intelligent quotient of an individual.

Accurate wavelengths for X-ray spectroscopy and the NIST hydrogen-like ion database

NASA Astrophysics Data System (ADS)

Kotochigova, S. A.; Kirby, K. P.; Brickhouse, N. S.; Mohr, P. J.; Tupitsyn, I. I.

2005-06-01

We have developed an ab initio multi-configuration Dirac-Fock-Sturm method for the precise calculation of X-ray emission spectra, including energies, transition wavelengths and transition probabilities. The calculations are based on non-orthogonal basis sets, generated by solving the Dirac-Fock and Dirac-Fock-Sturm equations. Inclusion of Sturm functions into the basis set provides an efficient description of correlation effects in highly charged ions and fast convergence of the configuration interaction procedure. A second part of our study is devoted to developing a theoretical procedure and creating an interactive database to generate energies and transition frequencies for hydrogen-like ions. This procedure is highly accurate and based on current knowledge of the relevant theory, which includes relativistic, quantum electrodynamic, recoil, and nuclear size effects.

A Systems-Theoretical Generalization of Non-Local Correlations

NASA Astrophysics Data System (ADS)

von Stillfried, Nikolaus

Non-local correlations between quantum events are not due to a causal interaction in the sense of one being the cause for the other. In principle, the correlated events can thus occur simultaneously. Generalized Quantum Theory (GQT) formalizes the idea that non-local phenomena are not exclusive to quantum mechanics, e.g. due to some specific properties of (sub)atomic particles, but that they instead arise as a consequence of the way such particles are arranged into systems. Non-local phenomena should hence occur in any system which fulfils the necessary systems-theoretical parameters. The two most important parameters with respect to non-local correlations seem to be a conserved global property of the system as a whole and sufficient degrees of freedom of the corresponding property of its subsystems. Both factors place severe limitations on experimental observability of the phenomena, especially in terms of replicability. It has been suggested that reported phenomena of a so-called synchronistic, parapsychological or paranormal kind could be understood as instances of systems-inherent non-local correlations. From a systems-theoretical perspective, their phenomenology (including the favorable conditions for their occurrence and their lack of replicability) displays substantial similarities to non-local correlations in quantum systems and matches well with systems-theoretical parameters, thus providing circumstantial evidence for this hypothesis.

Language Performance Assessment: Current Trends in Theory and Research

ERIC Educational Resources Information Center

El-Koumy, Abdel-Salam Abdel-Khalek

2004-01-01

The purpose of this paper is to review the theoretical and empirical literature relevant to language performance assessment. Following a definition of performance assessment, this paper considers: (1) theoretical assumptions underlying performance assessment; (2) purposes of performance assessment; (3) performance assessment procedures; (4) merits…

In their own words: Success stories from The Great Lakes Native American Research Center for Health.

PubMed

Dellinger, Matthew; Jackson, Brian; Poupart, Amy

2016-01-01

In 2009, the Great Lakes Native American Research Center for Health (GLNARCH) set out to generate a promotional video that highlights the successes of the program. Ten GLNARCH interns were interviewed and filmed for participation in the promotional video using a documentary production style. During the editing and transcription process, interviewer responses were noted for relevance to theoretical frameworks--specifically, tribal critical race theory, mentoring, and cultural compatibility--which guided GLNARCH program design. Quotations were transcribed to illustrate these themes. Though the interviews were not intended as a formal qualitative analysis, powerful narratives that are relevant to participatory research emerged. The emergence of narratives that align with relevant theoretical frameworks suggests a novel methodology for a culturally responsive, participatory reporting system.

The Impact of Semantic Relevance and Heterogeneity of Pictorial Stimuli on Individual Brainstorming: An Extension of the SIAM Model

ERIC Educational Resources Information Center

Guo, Jing; McLeod, Poppy Lauretta

2014-01-01

Drawing upon the Search for Ideas in Associative Memory (SIAM) model as the theoretical framework, the impact of heterogeneity and topic relevance of visual stimuli on ideation performance was examined. Results from a laboratory experiment showed that visual stimuli increased productivity and diversity of idea generation, that relevance to the…

Which Features Make Illustrations in Multimedia Learning Interesting?

ERIC Educational Resources Information Center

Magner, Ulrike Irmgard Elisabeth; Glogger, Inga; Renkl, Alexander

2016-01-01

How can illustrations motivate learners in multimedia learning? Which features make illustrations interesting? Beside the theoretical relevance of addressing these questions, these issues are practically relevant when instructional designers are to decide which features of illustrations can trigger situational interest irrespective of individual…

Determination of Relevant Neuron–Neuron Connections for Neural Prosthetics Using Time-Delayed Mutual Information: Tutorial and Preliminary Results

PubMed Central

Taghva, Alexander; Song, Dong; Hampson, Robert E.; Deadwyler, Sam A.; Berger, Theodore W.

2013-01-01

BACKGROUND Identification of functional dependence among neurons is a necessary component in both the rational design of neural prostheses as well as in the characterization of network physiology. The objective of this article is to provide a tutorial for neurosurgeons regarding information theory, specifically time-delayed mutual information, and to compare time-delayed mutual information, an information theoretic quantity based on statistical dependence, with cross-correlation, a commonly used metric for this task in a preliminary analysis of rat hippocampal neurons. METHODS Spike trains were recorded from rats performing delayed nonmatch-to-sample task using an array of electrodes surgically implanted into the hippocampus of each hemisphere of the brain. In addition, spike train simulations of positively correlated neurons, negatively correlated neurons, and neurons correlated by nonlinear functions were generated. These were evaluated by time-delayed mutual information (MI) and cross-correlation. RESULTS Application of time-delayed MI to experimental data indicated the optimal bin size for information capture in the CA3-CA1 system was 40 ms, which may provide some insight into the spatiotemporal nature of encoding in the rat hippocampus. On simulated data, time-delayed MI showed peak values at appropriate time lags in positively correlated, negatively correlated, and complexly correlated data. Cross-correlation showed peak and troughs with positively correlated and negatively correlated data, but failed to capture some higher order correlations. CONCLUSIONS Comparison of time-delayed MI to cross-correlation in identification of functionally dependent neurons indicates that the methods are not equivalent. Time-delayed MI appeared to capture some interactions between CA3-CA1 neurons at physiologically plausible time delays missed by cross-correlation. It should be considered as a method for identification of functional dependence between neurons and may be useful in the development of neural prosthetics. PMID:22120279

Determination of relevant neuron-neuron connections for neural prosthetics using time-delayed mutual information: tutorial and preliminary results.

PubMed

Taghva, Alexander; Song, Dong; Hampson, Robert E; Deadwyler, Sam A; Berger, Theodore W

2012-12-01

Identification of functional dependence among neurons is a necessary component in both the rational design of neural prostheses as well as in the characterization of network physiology. The objective of this article is to provide a tutorial for neurosurgeons regarding information theory, specifically time-delayed mutual information, and to compare time-delayed mutual information, an information theoretic quantity based on statistical dependence, with cross-correlation, a commonly used metric for this task in a preliminary analysis of rat hippocampal neurons. Spike trains were recorded from rats performing delayed nonmatch-to-sample task using an array of electrodes surgically implanted into the hippocampus of each hemisphere of the brain. In addition, spike train simulations of positively correlated neurons, negatively correlated neurons, and neurons correlated by nonlinear functions were generated. These were evaluated by time-delayed mutual information (MI) and cross-correlation. Application of time-delayed MI to experimental data indicated the optimal bin size for information capture in the CA3-CA1 system was 40 ms, which may provide some insight into the spatiotemporal nature of encoding in the rat hippocampus. On simulated data, time-delayed MI showed peak values at appropriate time lags in positively correlated, negatively correlated, and complexly correlated data. Cross-correlation showed peak and troughs with positively correlated and negatively correlated data, but failed to capture some higher order correlations. Comparison of time-delayed MI to cross-correlation in identification of functionally dependent neurons indicates that the methods are not equivalent. Time-delayed MI appeared to capture some interactions between CA3-CA1 neurons at physiologically plausible time delays missed by cross-correlation. It should be considered as a method for identification of functional dependence between neurons and may be useful in the development of neural prosthetics. Copyright © 2012 Elsevier Inc. All rights reserved.

Influence of the noise sources motion on the estimated Green's functions from ambient noise cross-correlations.

PubMed

Sabra, Karim G

2010-06-01

It has been demonstrated theoretically and experimentally that an estimate of the Green's function between two receivers can be obtained by cross-correlating acoustic (or elastic) ambient noise recorded at these two receivers. Coherent wavefronts emerge from the noise cross-correlation time function due to the accumulated contributions over time from noise sources whose propagation path pass through both receivers. Previous theoretical studies of the performance of this passive imaging technique have assumed that no relative motion between noise sources and receivers occurs. In this article, the influence of noise sources motion (e.g., aircraft or ship) on this passive imaging technique was investigated theoretically in free space, using a stationary phase approximation, for stationary receivers. The theoretical results were extended to more complex environments, in the high-frequency regime, using first-order expansions of the Green's function. Although sources motion typically degrades the performance of wideband coherent processing schemes, such as time-delay beamforming, it was found that the Green's function estimated from ambient noise cross-correlations are not expected to be significantly affected by the Doppler effect, even for supersonic sources. Numerical Monte-Carlo simulations were conducted to confirm these theoretical predictions for both cases of subsonic and supersonic moving sources.

Opioid Prescribing After Curative-Intent Surgery: A Qualitative Study Using the Theoretical Domains Framework.

PubMed

Lee, Jay S; Parashar, Vartika; Miller, Jacquelyn B; Bremmer, Samantha M; Vu, Joceline V; Waljee, Jennifer F; Dossett, Lesly A

2018-07-01

Excessive opioid prescribing is common after curative-intent surgery, but little is known about what factors influence prescribing behaviors among surgeons. To identify targets for intervention, we performed a qualitative study of opioid prescribing after curative-intent surgery using the Theoretical Domains Framework, a well-established implementation science method for identifying factors influencing healthcare provider behavior. Prior to data collection, we constructed a semi-structured interview guide to explore decision making for opioid prescribing. We then conducted interviews with surgical oncology providers at a single comprehensive cancer center. Interviews were recorded, transcribed verbatim, then independently coded by two investigators using the Theoretical Domains Framework to identify theoretical domains relevant to opioid prescribing. Relevant domains were then linked to behavior models to select targeted interventions likely to improve opioid prescribing. Twenty-one subjects were interviewed from November 2016 to May 2017, including attending surgeons, resident surgeons, physician assistants, and nurses. Five theoretical domains emerged as relevant to opioid prescribing: environmental context and resources; social influences; beliefs about consequences; social/professional role and identity; and goals. Using these domains, three interventions were identified as likely to change opioid prescribing behavior: (1) enablement (deploy nurses during preoperative visits to counsel patients on opioid use); (2) environmental restructuring (provide on-screen prompts with normative data on the quantity of opioid prescribed); and (3) education (provide prescribing guidelines). Key determinants of opioid prescribing behavior after curative-intent surgery include environmental and social factors. Interventions targeting these factors are likely to improve opioid prescribing in surgical oncology.

Logarithmic violation of scaling in strongly anisotropic turbulent transfer of a passive vector field

NASA Astrophysics Data System (ADS)

Antonov, N. V.; Gulitskiy, N. M.

2015-01-01

Inertial-range asymptotic behavior of a vector (e.g., magnetic) field, passively advected by a strongly anisotropic turbulent flow, is studied by means of the field-theoretic renormalization group and the operator product expansion. The advecting velocity field is Gaussian, not correlated in time, with the pair correlation function of the form ∝δ (t -t') /k⊥d -1 +ξ , where k⊥=|k⊥| and k⊥ is the component of the wave vector, perpendicular to the distinguished direction ("direction of the flow")—the d -dimensional generalization of the ensemble introduced by Avellaneda and Majda [Commun. Math. Phys. 131, 381 (1990), 10.1007/BF02161420]. The stochastic advection-diffusion equation for the transverse (divergence-free) vector field includes, as special cases, the kinematic dynamo model for magnetohydrodynamic turbulence and the linearized Navier-Stokes equation. In contrast to the well-known isotropic Kraichnan's model, where various correlation functions exhibit anomalous scaling behavior with infinite sets of anomalous exponents, here the dependence on the integral turbulence scale L has a logarithmic behavior: Instead of powerlike corrections to ordinary scaling, determined by naive (canonical) dimensions, the anomalies manifest themselves as polynomials of logarithms of L . The key point is that the matrices of scaling dimensions of the relevant families of composite operators appear nilpotent and cannot be diagonalized. The detailed proof of this fact is given for the correlation functions of arbitrary order.

Different Topological Properties of EEG-Derived Networks Describe Working Memory Phases as Revealed by Graph Theoretical Analysis

PubMed Central

Toppi, Jlenia; Astolfi, Laura; Risetti, Monica; Anzolin, Alessandra; Kober, Silvia E.; Wood, Guilherme; Mattia, Donatella

2018-01-01

Several non-invasive imaging methods have contributed to shed light on the brain mechanisms underlying working memory (WM). The aim of the present study was to depict the topology of the relevant EEG-derived brain networks associated to distinct operations of WM function elicited by the Sternberg Item Recognition Task (SIRT) such as encoding, storage, and retrieval in healthy, middle age (46 ± 5 years) adults. High density EEG recordings were performed in 17 participants whilst attending a visual SIRT. Neural correlates of WM were assessed by means of a combination of EEG signal processing methods (i.e., time-varying connectivity estimation and graph theory), in order to extract synthetic descriptors of the complex networks underlying the encoding, storage, and retrieval phases of WM construct. The group analysis revealed that the encoding phase exhibited a significantly higher small-world topology of EEG networks with respect to storage and retrieval in all EEG frequency oscillations, thus indicating that during the encoding of items the global network organization could “optimally” promote the information flow between WM sub-networks. We also found that the magnitude of such configuration could predict subject behavioral performance when memory load increases as indicated by the negative correlation between Reaction Time and the local efficiency values estimated during the encoding in the alpha band in both 4 and 6 digits conditions. At the local scale, the values of the degree index which measures the degree of in- and out- information flow between scalp areas were found to specifically distinguish the hubs within the relevant sub-networks associated to each of the three different WM phases, according to the different role of the sub-network of regions in the different WM phases. Our findings indicate that the use of EEG-derived connectivity measures and their related topological indices might offer a reliable and yet affordable approach to monitor WM components and thus theoretically support the clinical assessment of cognitive functions in presence of WM decline/impairment, as it occurs after stroke. PMID:29379425

The relationship between the spatial scaling of biodiversity and ecosystem stability

PubMed Central

Delsol, Robin; Loreau, Michel; Haegeman, Bart

2018-01-01

Aim Ecosystem stability and its link with biodiversity have mainly been studied at the local scale. Here we present a simple theoretical model to address the joint dependence of diversity and stability on spatial scale, from local to continental. Methods The notion of stability we use is based on the temporal variability of an ecosystem-level property, such as primary productivity. In this way, our model integrates the well-known species–area relationship (SAR) with a recent proposal to quantify the spatial scaling of stability, called the invariability–area relationship (IAR). Results We show that the link between the two relationships strongly depends on whether the temporal fluctuations of the ecosystem property of interest are more correlated within than between species. If fluctuations are correlated within species but not between them, then the IAR is strongly constrained by the SAR. If instead individual fluctuations are only correlated by spatial proximity, then the IAR is unrelated to the SAR. We apply these two correlation assumptions to explore the effects of species loss and habitat destruction on stability, and find a rich variety of multi-scale spatial dependencies, with marked differences between the two assumptions. Main conclusions The dependence of ecosystem stability on biodiversity across spatial scales is governed by the spatial decay of correlations within and between species. Our work provides a point of reference for mechanistic models and data analyses. More generally, it illustrates the relevance of macroecology for ecosystem functioning and stability. PMID:29651225

Instability behaviour of cosmic gravito-coupled correlative complex bi-fluidic admixture

NASA Astrophysics Data System (ADS)

Das, Papari; Karmakar, Pralay Kumar

2017-10-01

The gravitational instability of an unbounded infinitely extended composite gravitating cloud system composed of gravito-coupled neutral gaseous fluid (NGF) and dark matter fluid (DMF) is theoretically investigated in a classical framework. It is based on a spatially-flat geometry approximation (1D, sheet-like, boundless) at the backdrop that the radius of curvature of the gravito-confined bi-fluidic-boundary is much larger than all the hydro-characteristic scale lengths of interest. The relevant collective correlative dynamics, via the lowest-order mnemonic viscoelasticity, is mooted. We apply a standard formalism of normal mode analysis to yield a unique brand of generalized quadratic dispersion relation having variable multi-parametric coefficients dependent on the diversified equilibrium properties. It is parametrically seen that the DMF flow speed and the DMF viscoelasticity introduce stabilizing effects against the composite cloud collapse. The instability physiognomies, as specialized extreme corollaries, are in good accord with the previously reported predictions. The analysis may be widely useful to see the gravito-thermally coupled wave dynamics leading to the formation of large-scale hierarchical non-homologous structures in dark-matter-dominated dwarf galaxies.

Possibility to realize spin-orbit-induced correlated physics in iridium fluorides

NASA Astrophysics Data System (ADS)

Rossi, M.; Retegan, M.; Giacobbe, C.; Fumagalli, R.; Efimenko, A.; Kulka, T.; Wohlfeld, K.; Gubanov, A. I.; Moretti Sala, M.

2017-06-01

Recent theoretical predictions of "unprecedented proximity" of the electronic ground state of iridium fluorides to the SU(2) symmetric jeff=1 /2 limit, relevant for superconductivity in iridates, motivated us to investigate their crystal and electronic structure. To this aim, we performed high-resolution x-ray powder diffraction, Ir L3-edge resonant inelastic x-ray scattering, and quantum chemical calculations on Rb2[IrF6] and other iridium fluorides. Our results are consistent with the Mott insulating scenario predicted by Birol and Haule [Phys. Rev. Lett. 114, 096403 (2015), 10.1103/PhysRevLett.114.096403], but we observe a sizable deviation of the jeff=1 /2 state from the SU(2) symmetric limit. Interactions beyond the first coordination shell of iridium are negligible, hence the iridium fluorides do not show any magnetic ordering down to at least 20 K. A larger spin-orbit coupling in iridium fluorides compared to oxides is ascribed to a reduction of the degree of covalency, with consequences on the possibility to realize spin-orbit-induced strongly correlated physics in iridium fluorides.

Use of Multivariate Linkage Analysis for Dissection of a Complex Cognitive Trait

PubMed Central

Marlow, Angela J.; Fisher, Simon E.; Francks, Clyde; MacPhie, I. Laurence; Cherny, Stacey S.; Richardson, Alex J.; Talcott, Joel B.; Stein, John F.; Monaco, Anthony P.; Cardon, Lon R.

2003-01-01

Replication of linkage results for complex traits has been exceedingly difficult, owing in part to the inability to measure the precise underlying phenotype, small sample sizes, genetic heterogeneity, and statistical methods employed in analysis. Often, in any particular study, multiple correlated traits have been collected, yet these have been analyzed independently or, at most, in bivariate analyses. Theoretical arguments suggest that full multivariate analysis of all available traits should offer more power to detect linkage; however, this has not yet been evaluated on a genomewide scale. Here, we conduct multivariate genomewide analyses of quantitative-trait loci that influence reading- and language-related measures in families affected with developmental dyslexia. The results of these analyses are substantially clearer than those of previous univariate analyses of the same data set, helping to resolve a number of key issues. These outcomes highlight the relevance of multivariate analysis for complex disorders for dissection of linkage results in correlated traits. The approach employed here may aid positional cloning of susceptibility genes in a wide spectrum of complex traits. PMID:12587094

Dynamic scaling in natural swarms

NASA Astrophysics Data System (ADS)

Cavagna, Andrea; Conti, Daniele; Creato, Chiara; Del Castello, Lorenzo; Giardina, Irene; Grigera, Tomas S.; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano

2017-09-01

Collective behaviour in biological systems presents theoretical challenges beyond the borders of classical statistical physics. The lack of concepts such as scaling and renormalization is particularly problematic, as it forces us to negotiate details whose relevance is often hard to assess. In an attempt to improve this situation, we present here experimental evidence of the emergence of dynamic scaling laws in natural swarms of midges. We find that spatio-temporal correlation functions in different swarms can be rescaled by using a single characteristic time, which grows with the correlation length with a dynamical critical exponent z ~ 1, a value not found in any other standard statistical model. To check whether out-of-equilibrium effects may be responsible for this anomalous exponent, we run simulations of the simplest model of self-propelled particles and find z ~ 2, suggesting that natural swarms belong to a novel dynamic universality class. This conclusion is strengthened by experimental evidence of the presence of non-dissipative modes in the relaxation, indicating that previously overlooked inertial effects are needed to describe swarm dynamics. The absence of a purely dissipative regime suggests that natural swarms undergo a near-critical censorship of hydrodynamics.

Computational assessment of hemodynamics-based diagnostic tools using a database of virtual subjects: Application to three case studies.

PubMed

Willemet, Marie; Vennin, Samuel; Alastruey, Jordi

2016-12-08

Many physiological indexes and algorithms based on pulse wave analysis have been suggested in order to better assess cardiovascular function. Because these tools are often computed from in-vivo hemodynamic measurements, their validation is time-consuming, challenging, and biased by measurement errors. Recently, a new methodology has been suggested to assess theoretically these computed tools: a database of virtual subjects generated using numerical 1D-0D modeling of arterial hemodynamics. The generated set of simulations encloses a wide selection of healthy cases that could be encountered in a clinical study. We applied this new methodology to three different case studies that demonstrate the potential of our new tool, and illustrated each of them with a clinically relevant example: (i) we assessed the accuracy of indexes estimating pulse wave velocity; (ii) we validated and refined an algorithm that computes central blood pressure; and (iii) we investigated theoretical mechanisms behind the augmentation index. Our database of virtual subjects is a new tool to assist the clinician: it provides insight into the physical mechanisms underlying the correlations observed in clinical practice. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Cold-Rolled Strip Steel Stress Detection Technology Based on a Magnetoresistance Sensor and the Magnetoelastic Effect

PubMed Central

Guan, Ben; Zang, Yong; Han, Xiaohui; Zheng, Kailun

2018-01-01

Driven by the demands for contactless stress detection, technologies are being used for shape control when producing cold-rolled strips. This paper presents a novel contactless stress detection technology based on a magnetoresistance sensor and the magnetoelastic effect, enabling the detection of internal stress in manufactured cold-rolled strips. An experimental device was designed and produced. Characteristics of this detection technology were investigated through experiments assisted by theoretical analysis. Theoretically, a linear correlation exists between the internal stress of strip steel and the voltage output of a magneto-resistive sensor. Therefore, for this stress detection system, the sensitivity of the stress detection was adjusted by adjusting the supply voltage of the magnetoresistance sensor, detection distance, and other relevant parameters. The stress detection experimental results showed that this detection system has good repeatability and linearity. The detection error was controlled within 1.5%. Moreover, the intrinsic factors of the detected strip steel, including thickness, carbon percentage, and crystal orientation, also affected the sensitivity of the detection system. The detection technology proposed in this research enables online contactless detection and meets the requirements for cold-rolled steel strips. PMID:29883387

What's in a norm? Sources and processes of norm change.

PubMed

Paluck, Elizabeth Levy

2009-03-01

This reply to the commentary by E. Staub and L. A. Pearlman (2009) revisits the field experimental results of E. L. Paluck (2009). It introduces further evidence and theoretical elaboration supporting Paluck's conclusion that exposure to a reconciliation-themed radio soap opera changed perceptions of social norms and behaviors, not beliefs. Experimental and longitudinal survey evidence reinforces the finding that the radio program affected socially shared perceptions of typical or prescribed behavior-that is, social norms. Specifically, measurements of perceptions of social norms called into question by Staub and Pearlman are shown to correlate with perceptions of public opinion and public, not private, behaviors. Although measurement issues and the mechanisms of the radio program's influence merit further testing, theory and evidence point to social interactions and emotional engagement, not individual education, as the likely mechanisms of change. The present exchange makes salient what is at stake in this debate: a model of change based on learning and personal beliefs versus a model based on group influence and social norms. These theoretical models recommend very different strategies for prejudice and conflict reduction. Future field experiments should attempt to adjudicate between these models by testing relevant policies in real-world settings.

Cold-Rolled Strip Steel Stress Detection Technology Based on a Magnetoresistance Sensor and the Magnetoelastic Effect.

PubMed

Guan, Ben; Zang, Yong; Han, Xiaohui; Zheng, Kailun

2018-05-21

Driven by the demands for contactless stress detection, technologies are being used for shape control when producing cold-rolled strips. This paper presents a novel contactless stress detection technology based on a magnetoresistance sensor and the magnetoelastic effect, enabling the detection of internal stress in manufactured cold-rolled strips. An experimental device was designed and produced. Characteristics of this detection technology were investigated through experiments assisted by theoretical analysis. Theoretically, a linear correlation exists between the internal stress of strip steel and the voltage output of a magneto-resistive sensor. Therefore, for this stress detection system, the sensitivity of the stress detection was adjusted by adjusting the supply voltage of the magnetoresistance sensor, detection distance, and other relevant parameters. The stress detection experimental results showed that this detection system has good repeatability and linearity. The detection error was controlled within 1.5%. Moreover, the intrinsic factors of the detected strip steel, including thickness, carbon percentage, and crystal orientation, also affected the sensitivity of the detection system. The detection technology proposed in this research enables online contactless detection and meets the requirements for cold-rolled steel strips.

Theoretical Explanation for Success of Deep-Level-Learning Study Tours

ERIC Educational Resources Information Center

Bergsteiner, Harald; Avery, Gayle C.

2008-01-01

Study tours can help internationalize curricula and prepare students for global workplaces. We examine benefits of tours providing deep-level learning experiences rather than industrial tourism using five main theoretical frameworks to highlight the diverse learning benefits associated with intensive study tours in particular. Relevant theoretical…

Traversing New Theoretical Frames for Intercultural Education: Gender, Intersectionality, Performativity

ERIC Educational Resources Information Center

Gregoriou, Zelia

2013-01-01

This paper attempts to renegotiate the conceptual and political borders of intercultural education by importing ways of thinking, concepts, aporias and questions relevant to a gendered study of intercultural interactions from theoretical terrains outside the disciplinary borders and discursive limits of intercultural education. A number of…

Theoretical Definition of Instructor Role in Computer-Managed Instruction.

ERIC Educational Resources Information Center

McCombs, Barbara L.; Dobrovolny, Jacqueline L.

This report describes the results of a theoretical analysis of the ideal role functions of the Computer Managed Instruction (CMI) instructor. Concepts relevant to instructor behavior are synthesized from both cognitive and operant learning theory perspectives, and the roles allocated to instructors by seven large-scale operational CMI systems are…

The Community-First Land-Centred Theoretical Framework: Bringing a "Good Mind" to Indigenous Education Research?

ERIC Educational Resources Information Center

Styres, Sandra D.; Zinga, Dawn M.

2013-01-01

This article introduces an emergent research theoretical framework, the community-first Land-centred research framework. Carefully examining the literature within Indigenous educational research, we noted the limited approaches for engaging in culturally aligned and relevant research within Indigenous communities. The community-first Land-centred…

NLPIR: A Theoretical Framework for Applying Natural Language Processing to Information Retrieval.

ERIC Educational Resources Information Center

Zhou, Lina; Zhang, Dongsong

2003-01-01

Proposes a theoretical framework called NLPIR that integrates natural language processing (NLP) into information retrieval (IR) based on the assumption that there exists representation distance between queries and documents. Discusses problems in traditional keyword-based IR, including relevance, and describes some existing NLP techniques.…

Papers on Theoretical Issues in Health Education.

ERIC Educational Resources Information Center

California Univ., Berkeley. School of Public Health.

This document is a collection of 17 papers on theoretical issues in health education presented at the Dorothy Nyswander International Symposium. The introduction, entitled "Theory and Practice in Health Education: A Synthesis," attempts to highlight some of the features of these papers and their relevance for health education practice. The papers…

A Holistic Theoretical Approach to Intellectual Disability: Going Beyond the Four Current Perspectives.

PubMed

Schalock, Robert L; Luckasson, Ruth; Tassé, Marc J; Verdugo, Miguel Angel

2018-04-01

This article describes a holistic theoretical framework that can be used to explain intellectual disability (ID) and organize relevant information into a usable roadmap to guide understanding and application. Developing the framework involved analyzing the four current perspectives on ID and synthesizing this information into a holistic theoretical framework. Practices consistent with the framework are described, and examples are provided of how multiple stakeholders can apply the framework. The article concludes with a discussion of the advantages and implications of a holistic theoretical approach to ID.

Culturally Relevant Physical Education in Urban Schools: Reflecting Cultural Knowledge

ERIC Educational Resources Information Center

Flory, Sara B.; McCaughtry, Nate

2011-01-01

Using a three-part theoretical framework, the cultural relevance cycle--which consists of (a) knowing community dynamics, (b) knowing how community dynamics influence educational processes, and (c) implementing strategies that reflect cultural knowledge of the community--we examined teachers' and students' perspectives on culturally relevant…

Sensitivity Training: Relevance for Social Work Education.

ERIC Educational Resources Information Center

Papell, Catherine P.

The author explores the validity of sensitivity training for professional social work education with its inherent concern for the relation between experiential and theoretical learning. The various streams in the sensitivity training movement are surveyed and the laboratory concept identified as particularly relevant. A human relations laboratory,…

On the relationship between matched filter theory as applied to gust loads and phased design loads analysis

NASA Technical Reports Server (NTRS)

Zeiler, Thomas A.; Pototzky, Anthony S.

1989-01-01

A theoretical basis and example calculations are given that demonstrate the relationship between the Matched Filter Theory approach to the calculation of time-correlated gust loads and Phased Design Load Analysis in common use in the aerospace industry. The relationship depends upon the duality between Matched Filter Theory and Random Process Theory and upon the fact that Random Process Theory is used in Phased Design Loads Analysis in determining an equiprobable loads design ellipse. Extensive background information describing the relevant points of Phased Design Loads Analysis, calculating time-correlated gust loads with Matched Filter Theory, and the duality between Matched Filter Theory and Random Process Theory is given. It is then shown that the time histories of two time-correlated gust load responses, determined using the Matched Filter Theory approach, can be plotted as parametric functions of time and that the resulting plot, when superposed upon the design ellipse corresponding to the two loads, is tangent to the ellipse. The question is raised of whether or not it is possible for a parametric load plot to extend outside the associated design ellipse. If it is possible, then the use of the equiprobable loads design ellipse will not be a conservative design practice in some circumstances.

Measurement of prosocial reasoning among Chinese adolescents.

PubMed

Lai, Frank H Y; Siu, Andrew M H; Chan, Chewtyn C H; Shek, Daniel T L

2012-01-01

This study attempted to develop a standardized instrument for assessment of prosocial reasoning in Chinese populations. The Prosocial Reasoning Objective Measure (PROM) was translated, and a two-stage study was conducted to evaluate the psychometric properties of the translated instrument. The content validity, cultural relevance, and reading level of the translated instrument were evaluated by an expert panel. Upon revisions according to the expert opinions, the Chinese PROM demonstrated good content validity, "good-to-very good test-retest" reliability, and internal consistency. However, only partial support to the convergent validity of the Chinese PROM was found. In the first stage of the study (n = 50), the PROM scores had high positive correlations with empathy and negative correlations with personal distress and fantasy. These results were consistent with theoretical expectations, although this is also a concern that empathy had a close-to-unity correlation with PROM score in the small sample study of stage 1. In the second stage of the study (n = 566), the relationship between PROM scores and prosocial behavior appeared to be weak. Results suggest that there were many personal, family, or social factors that were linked to prosocial behavior, and prosocial reasoning might only contribute to a small proportion of variation in prosocial behavior among adolescents.

Measurement of Prosocial Reasoning among Chinese Adolescents

PubMed Central

Lai, Frank H. Y.; Siu, Andrew M. H.; Chan, Chewtyn C. H.; Shek, Daniel T. L.

2012-01-01

This study attempted to develop a standardized instrument for assessment of prosocial reasoning in Chinese populations. The Prosocial Reasoning Objective Measure (PROM) was translated, and a two-stage study was conducted to evaluate the psychometric properties of the translated instrument. The content validity, cultural relevance, and reading level of the translated instrument were evaluated by an expert panel. Upon revisions according to the expert opinions, the Chinese PROM demonstrated good content validity, “good-to-very good test-retest” reliability, and internal consistency. However, only partial support to the convergent validity of the Chinese PROM was found. In the first stage of the study (n = 50), the PROM scores had high positive correlations with empathy and negative correlations with personal distress and fantasy. These results were consistent with theoretical expectations, although this is also a concern that empathy had a close-to-unity correlation with PROM score in the small sample study of stage 1. In the second stage of the study (n = 566), the relationship between PROM scores and prosocial behavior appeared to be weak. Results suggest that there were many personal, family, or social factors that were linked to prosocial behavior, and prosocial reasoning might only contribute to a small proportion of variation in prosocial behavior among adolescents. PMID:22919293

Caprylate Salts Based on Amines as Volatile Corrosion Inhibitors for Metallic Zinc: Theoretical and Experimental Studies.

PubMed

Valente, Marco A G; Teixeira, Deiver A; Azevedo, David L; Feliciano, Gustavo T; Benedetti, Assis V; Fugivara, Cecílio S

2017-01-01

The interaction of volatile corrosion inhibitors (VCI), caprylate salt derivatives from amines, with zinc metallic surfaces is assessed by density functional theory (DFT) computer simulations, electrochemical impedance (EIS) measurements and humid chamber tests. The results obtained by the different methods were compared, and linear correlations were obtained between theoretical and experimental data. The correlations between experimental and theoretical results showed that the molecular size is the determining factor in the inhibition efficiency. The models used and experimental results indicated that dicyclohexylamine caprylate is the most efficient inhibitor.

Nanosecond Dynamics at Protein Metal Sites: An Application of Perturbed Angular Correlation (PAC) of γ-Rays Spectroscopy.

PubMed

Chakraborty, Saumen; Pallada, Stavroula; Pedersen, Jeppe T; Jancso, Attila; Correia, Joao G; Hemmingsen, Lars

2017-09-19

Metalloproteins are essential to numerous reactions in nature, and constitute approximately one-third of all known proteins. Molecular dynamics of proteins has been elucidated with great success both by experimental and theoretical methods, revealing atomic level details of function involving the organic constituents on a broad spectrum of time scales. However, the characterization of dynamics at biomolecular metal sites on nanosecond time scales is scarce in the literature. The aqua ions of many biologically relevant metal ions exhibit exchange of water molecules on the nanosecond time scale or faster, often defining their reactivity in aqueous solution, and this is presumably also a relevant time scale for the making and breaking of coordination bonds between metal ions and ligands at protein metal sites. Ligand exchange dynamics is critical for a variety of elementary steps of reactions in metallobiochemistry, for example, association and dissociation of metal bound water, association of substrate and dissociation of product in the catalytic cycle of metalloenzymes, at regulatory metal sites which require binding and dissociation of metal ions, as well as in the transport of metal ions across cell membranes or between proteins involved in metal ion homeostasis. In Perturbed Angular Correlation of γ-rays (PAC) spectroscopy, the correlation in time and space of two γ-rays emitted successively in a nuclear decay is recorded, reflecting the hyperfine interactions of the PAC probe nucleus with the surroundings. This allows for characterization of molecular and electronic structure as well as nanosecond dynamics at the PAC probe binding site. Herein, selected examples describing the application of PAC spectroscopy in probing the dynamics at protein metal sites are presented, including (1) exchange of Cd 2+ bound water in de novo designed synthetic proteins, and the effect of remote mutations on metal site dynamics; (2) dynamics at the β-lactamase active site, where the metal ion appears to jump between the two adjacent sites; (3) structural relaxation in small blue copper proteins upon 111 Ag + to 111 Cd 2+ transformation in radioactive nuclear decay; (4) metal ion transfer between two HAH1 proteins with change in coordination number; and (5) metal ion sensor proteins with two coexisting metal site structures. With this Account, we hope to make our modest contribution to the field and perhaps spur additional interest in dynamics at protein metal sites, which we consider to be severely underexplored. Relatively little is known about detailed atomic motions at metal sites, for example, how ligand exchange processes affect protein function, and how the amino acid composition of the protein may control this facet of metal site characteristics. We also aim to provide the reader with a qualitative impression of the possibilities offered by PAC spectroscopy in bioinorganic chemistry, especially when elucidating dynamics at protein metal sites, and finally present data that may serve as benchmarks on a relevant time scale for development and tests of theoretical molecular dynamics methods applied to biomolecular metal sites.

Universality of fast quenches from the conformal perturbation theory

NASA Astrophysics Data System (ADS)

Dymarsky, Anatoly; Smolkin, Michael

2018-01-01

We consider global quantum quenches, a protocol when a continuous field theoretic system in the ground state is driven by a homogeneous time-dependent external interaction. When the typical inverse time scale of the interaction is much larger than all relevant scales except for the UV-cutoff the system's response exhibits universal scaling behavior. We provide both qualitative and quantitative explanations of this universality and argue that physics of the response during and shortly after the quench is governed by the conformal perturbation theory around the UV fixed point. We proceed to calculate the response of one and two-point correlation functions confirming and generalizing universal scalings found previously. Finally, we discuss late time behavior after the quench and argue that all local quantities will equilibrate to their thermal values specified by an excess energy acquired by the system during the quench.

Assessing Relevance of External Cognitive Measures

PubMed Central

Cairó, Osvaldo

2017-01-01

The arrival of modern brain imaging technologies has provided new opportunities for examining the biological essence of human intelligence as well as the relationship between brain size and cognition. Thanks to these advances, we can now state that the relationship between brain size and intelligence has never been well understood. This view is supported by findings showing that cognition is correlated more with brain tissues than sheer brain size. The complexity of cellular and molecular organization of neural connections actually determines the computational capacity of the brain. In this review article, we determine that while genotypes are responsible for defining the theoretical limits of intelligence, what is primarily responsible for determining whether those limits are reached or exceeded is experience (environmental influence). Therefore, we contend that the gene-environment interplay defines the intelligent quotient of an individual. PMID:28270753

Single-electron thermal devices coupled to a mesoscopic gate

NASA Astrophysics Data System (ADS)

Sánchez, Rafael; Thierschmann, Holger; Molenkamp, Laurens W.

2017-11-01

We theoretically investigate the propagation of heat currents in a three-terminal quantum dot engine. Electron-electron interactions introduce state-dependent processes which can be resolved by energy-dependent tunneling rates. We identify the relevant transitions which define the operation of the system as a thermal transistor or a thermal diode. In the former case, thermal-induced charge fluctuations in the gate dot modify the thermal currents in the conductor with suppressed heat injection, resulting in huge amplification factors and the possible gating with arbitrarily low energy cost. In the latter case, enhanced correlations of the state-selective tunneling transitions redistribute heat flows giving high rectification coefficients and the unexpected cooling of one conductor terminal by heating the other one. We propose quantum dot arrays as a possible way to achieve the extreme tunneling asymmetries required for the different operations.

Fluid Dynamics and Solidification of Molten Solder Droplets Impacting on a Substrate in Microgravity

NASA Technical Reports Server (NTRS)

Megardis, C. M.; Poulikakos, D.; Diversiev, G.; Boomsma, K.; Xiong, B.; Nayagam, V.

1999-01-01

This program investigates the fluid dynamics and simultaneous solidification of molten solder droplets impacting on a flat smooth substrate. The problem of interest is directly relevant to the printing of microscopic solder droplets in surface mounting of microelectronic devices. The study consists of a theoretical and an experimental component. The theoretical work uses axisymmetric Navier-Stokes models based on finite element techniques. The experimental work will be ultimately performed in microgravity in order to allow for the use of larger solder droplets which make feasible the performance of accurate measurements, while maintaining similitude of the relevant fluid dynamics groups (Re, We).

Fluid Dynamics and Solidification of Molten Solder Droplets Impacting on a Substrate in Microgravity

NASA Technical Reports Server (NTRS)

Poulikakos, Dimos; Megaridis, Constantine M.; Vedha-Nayagam, M.

1996-01-01

This program investigates the fluid dynamics and simultaneous solidification of molten solder droplets impacting on a flat substrate. The problem of interest is directly relevant to the printing of microscopic solder droplets in surface mounting of microelectronic devices. The study consists of a theoretical and an experimental component. The theoretical work uses axisymmetric Navier-Stokes models based on finite element techniques. The experimental work is performed in microgravity to allow for the use of larger solder droplets that make feasible the performance of accurate measurements while maintaining similitude of the relevant fluid dynamics groups (Re, We) and keeping the effect of gravity negligible.

Walking towards Instrumental Appropriation of Mobile Devices. A Comparison of Studies

ERIC Educational Resources Information Center

Hernandez Serrano, Maria José; Yang, Lingling

2013-01-01

The study of instrumental appropriation is considered a relevant outstanding and productive perspective in the arena of Mobile ICT and learning. This paper seeks for the consolidation of this perspective at a theoretical and analytical level. Regarding the theoretical level, two characteristics of mobile devices--flexibility and mobility--are…

Swapping Settings: Researching Information Literacy in Workplace and in Educational Contexts

ERIC Educational Resources Information Center

Lundh, Anna Hampson; Limberg, Louise; Lloyd, Annemaree

2013-01-01

Introduction: Information literacy research is characterised by a multitude of interests, research approaches and theoretical starting-points. Challenges lie in the relevance of research to professional fields where information literacy is a concern, and the need to build a strong theoretical base for the research area. We aim to lay a foundation…

The Public Library User and the Charter Tourist: Two Travellers, One Analogy

ERIC Educational Resources Information Center

Eriksson, Catarina A. M.; Michnik, Katarina E.; Nordeborg, Yoshiko

2013-01-01

Introduction: A new theoretical model, relevant to library and information science, is implemented in this paper. The aim of this study is to contribute to the theoretical concepts of library and information science by introducing an ethnological model developed for investigating charter tourist styles thereby increasing our knowledge of users'…

The Role of the Family in Genetic Testing: Theoretical Perspectives, Current Knowledge, and Future Directions

ERIC Educational Resources Information Center

Peterson, Susan K.

2005-01-01

This article addresses conceptual challenges and theoretical approaches for examining the role of the family in responding and adapting to genetic testing for inherited conditions. Using a family systems perspective, family-based constructs that are relevant to genetic testing may be organized into three domains: family communication, organization…

Towards Improved Student Experiences in Service Learning in Information Systems Courses

ERIC Educational Resources Information Center

Petkova, Olga

2017-01-01

The paper explores relevant past research on service-learning in Information Systems courses since 2000. One of the conclusions from this is that most of the publications are not founded on specific theoretical models and are mainly about sharing instructor or student experiences. Then several theoretical frameworks from Education and other…

Interrelations in Cognition and Affect in Infancy: A Comparison of Piagetian, Psychoanalytic, and Eriksonian Theories.

ERIC Educational Resources Information Center

Mowbray, Carol T.

This paper presents a theoretical and empirical analysis of Piagetian and psychoanalytic theories of infancy to establish the developmental relationships between cognition and affect. Theoretical points of similarity and dissimilarity are cited. Relevant reasearch studies (Bell, Gouin-Decarie, Fraiberg) are reviewed in an attempt to resolve…

A Holistic Theoretical Approach to Intellectual Disability: Going beyond the Four Current Perspectives

ERIC Educational Resources Information Center

Schalock, Robert L.; Luckasson, Ruth; Tassé, Marc J.; Verdugo, Miguel Angel

2018-01-01

This article describes a holistic theoretical framework that can be used to explain intellectual disability (ID) and organize relevant information into a usable roadmap to guide understanding and application. Developing the framework involved analyzing the four current perspectives on ID and synthesizing this information into a holistic…

Coherent Structures in Plasmas Relevant to Electric Propulsion

DTIC Science & Technology

2016-06-24

AFRL-AFOSR-VA-TR-2016-0229 Coherent Structures in Plasmas Relevant to Electric Propulsion Mark Cappelli LELAND STANFORD JUNIOR UNIV CA Final Report...TITLE AND SUBTITLE Coherent Structures in Plasmas Relevant to Electric Propulsion 5a. CONTRACT NUMBER N/A 5b. GRANT NUMBER FA9550-14-1-0017 5c...to propulsion devices through experimental, theoretical, and numerical studies. 15. SUBJECT TERMS Plasma instabilities in magnetized discharges

The Role of Reader Characteristics in Processing and Learning from Informational Text

ERIC Educational Resources Information Center

Fox, Emily

2009-01-01

This article considers the role of reader characteristics in processing and learning from informational text, as revealed in think-aloud research. A theoretical framework for relevant aspects of readers' processing and products was developed. These relevant aspects included three attentional foci for processing (comprehension, monitoring, and…

Keeping Academically Marginal Youth in School.

ERIC Educational Resources Information Center

Alpert, Geoffrey; Dunham, Roger

1986-01-01

From among factors theoretically considered relevant to preventing school dropouts, empirical procedures identified five variables that predicted most of the variance among marginal youth: (1) extent of misbehavior in school; (2) belief in school's relevance to employment; (3) feelings of success in school; (4) parental monitoring of behavior; (5)…

The Future of School Board Governance: Relevancy and Revelation

ERIC Educational Resources Information Center

Alsbury, Thomas L.

2008-01-01

This book combines theoretical debate and empirical evidence of the effectiveness and relevancy of local school boards today. Original theorists of competing school board governance theories, current researchers, and researcher/practitioners provided the latest empirical data about the role of school boards as well as applications for…

Financing--The Basis of Organization and Realization of the Investment Policy of Russian Enterprises

ERIC Educational Resources Information Center

Charaeva, Marina V.; Naumova, Olga A.; Kosyakova, Inessa V.; Denisov, Aleksandr D.

2016-01-01

The relevance of the research: the relevance of research problem caused the necessity in organization investment policy of Russian enterprises for intensification of their strategic investment development and insufficient development of theoretical and methodological aspects in attracting financial resources for the realization of investment…

The Study of Aggressive Pornography: The Vicissitudes of Relevance.

ERIC Educational Resources Information Center

Brannigan, Augustine; Goldenberg, Sheldon

1987-01-01

Reviews experimental studies of behavioral consequences of exposure to violent or aggressive pornography and evaluates the validity and relevance as support for censoring pornography in the aftermath of the Meese Commission. Finds research deficient in several areas, such as design, theoretical models, and interpretation, thus offering no…

Incurable suffering from the "hiatus theoreticus"? Some epistemological problems in modern medicine and the clinical relevance of philosophy of medicine.

PubMed

Paul, N

1998-06-01

Up to now neither the question, whether all theoretical medical knowledge can at least be described as scientific, nor the one how exactly access to the existing scientific and theoretical medical knowledge during clinical problem-solving is made, has been sufficiently answered. Scientific theories play an important role in controlling clinical practice and improving the quality of clinical care in modern medicine on the one hand, and making it vindicable on the other. Therefore, the vagueness of unexplicit interrelations between medicine's stock of knowledge and medical practice appears as a gap in the theoretical concept of modern medicine which can be described as "Hiatus theoreticus" in the anatomy of medicine. A central intention of the paper is to analyze the role of philosophy of medicine for the clarification of the theoretical basis of medical practice. Clinical relevance and normativity in the sense of modern theory of science are suggested as criteria to establish a differentiation between philosophy of medicine as a primary medical discipline and the application of general philosophy in medicine.

Maintenance of a gluten free diet in coeliac disease: The roles of self-regulation, habit, psychological resources, motivation, support, and goal priority.

PubMed

Sainsbury, Kirby; Halmos, Emma P; Knowles, Simon; Mullan, Barbara; Tye-Din, Jason A

2018-06-01

A strict lifelong gluten free diet (GFD) is the only treatment for coeliac disease (CD). Theory-based research has focused predominantly on initiation, rational, and motivational processes in predicting adherence. The aim of this study was to evaluate an expanded collection of theoretical constructs specifically relevant to the maintenance of behaviour change, in the understanding and prediction of GFD adherence. Respondents with CD (N = 5573) completed measures of GFD adherence, psychological distress, intentions, self-efficacy, and the maintenance-relevant constructs of self-regulation, habit, temptation and intentional and unintentional lapses (cognitive and behavioural consequences of lowered or fluctuating psychological resources and self-control), motivation, social and environmental support, and goal priority, conflict, and facilitation. Correlations and multiple regression were used to determine their influence on adherence, over and above intention and self-efficacy, and how relationships changed in the presence of distress. Better adherence was associated with greater self-regulation, habit, self-efficacy, priority, facilitation, and support; and lower psychological distress, conflict, and fewer self-control lapses (e.g., when busy/stressed). Autonomous and wellbeing-based, but not controlled motivations, were related to adherence. In the presence of distress, the influence of self-regulation and intentional lapses on adherence were increased, while temptation and unintentional lapses were decreased. The findings point to the importance of considering intentional, volitional, automatic, and emotional processes in the understanding and prediction of GFD adherence. Behaviour change interventions and psychological support are now needed so that theoretical knowledge can be translated into evidence-based care, including a role for psychologists within the multi-disciplinary treatment team. Copyright © 2018 Elsevier Ltd. All rights reserved.

Acquiring neural signals for developing a perception and cognition model

NASA Astrophysics Data System (ADS)

Li, Wei; Li, Yunyi; Chen, Genshe; Shen, Dan; Blasch, Erik; Pham, Khanh; Lynch, Robert

2012-06-01

The understanding of how humans process information, determine salience, and combine seemingly unrelated information is essential to automated processing of large amounts of information that is partially relevant, or of unknown relevance. Recent neurological science research in human perception, and in information science regarding contextbased modeling, provides us with a theoretical basis for using a bottom-up approach for automating the management of large amounts of information in ways directly useful for human operators. However, integration of human intelligence into a game theoretic framework for dynamic and adaptive decision support needs a perception and cognition model. For the purpose of cognitive modeling, we present a brain-computer-interface (BCI) based humanoid robot system to acquire brainwaves during human mental activities of imagining a humanoid robot-walking behavior. We use the neural signals to investigate relationships between complex humanoid robot behaviors and human mental activities for developing the perception and cognition model. The BCI system consists of a data acquisition unit with an electroencephalograph (EEG), a humanoid robot, and a charge couple CCD camera. An EEG electrode cup acquires brainwaves from the skin surface on scalp. The humanoid robot has 20 degrees of freedom (DOFs); 12 DOFs located on hips, knees, and ankles for humanoid robot walking, 6 DOFs on shoulders and arms for arms motion, and 2 DOFs for head yaw and pitch motion. The CCD camera takes video clips of the human subject's hand postures to identify mental activities that are correlated to the robot-walking behaviors. We use the neural signals to investigate relationships between complex humanoid robot behaviors and human mental activities for developing the perception and cognition model.

Understanding the amplitudes of noise correlation measurements

USGS Publications Warehouse

Tsai, Victor C.

2011-01-01

Cross correlation of ambient seismic noise is known to result in time series from which station-station travel-time measurements can be made. Part of the reason that these cross-correlation travel-time measurements are reliable is that there exists a theoretical framework that quantifies how these travel times depend on the features of the ambient noise. However, corresponding theoretical results do not currently exist to describe how the amplitudes of the cross correlation depend on such features. For example, currently it is not possible to take a given distribution of noise sources and calculate the cross correlation amplitudes one would expect from such a distribution. Here, we provide a ray-theoretical framework for calculating cross correlations. This framework differs from previous work in that it explicitly accounts for attenuation as well as the spatial distribution of sources and therefore can address the issue of quantifying amplitudes in noise correlation measurements. After introducing the general framework, we apply it to two specific problems. First, we show that we can quantify the amplitudes of coherency measurements, and find that the decay of coherency with station-station spacing depends crucially on the distribution of noise sources. We suggest that researchers interested in performing attenuation measurements from noise coherency should first determine how the dominant sources of noise are distributed. Second, we show that we can quantify the signal-to-noise ratio of noise correlations more precisely than previous work, and that these signal-to-noise ratios can be estimated for given situations prior to the deployment of seismometers. It is expected that there are applications of the theoretical framework beyond the two specific cases considered, but these applications await future work.

The Effect of Error Correlation on Interfactor Correlation in Psychometric Measurement

ERIC Educational Resources Information Center

Westfall, Peter H.; Henning, Kevin S. S.; Howell, Roy D.

2012-01-01

This article shows how interfactor correlation is affected by error correlations. Theoretical and practical justifications for error correlations are given, and a new equivalence class of models is presented to explain the relationship between interfactor correlation and error correlations. The class allows simple, parsimonious modeling of error…

Brain profiling and clinical-neuroscience.

PubMed

Peled, Avi

2006-01-01

The current psychiatric diagnostic system, the diagnostic statistic manual, has recently come under increasing criticism. The major reason for the shortcomings of the current psychiatric diagnosis is the lack of a scientific brain-related etiological knowledge about mental disorders. The advancement toward such knowledge is further hampered by the lack of a theoretical framework or "language" that translates clinical findings of mental disorders to brain disturbances and insufficiencies. Here such a theoretical construct is proposed based on insights from neuroscience and neural-computation models. Correlates between clinical manifestations and presumed neuronal network disturbances are proposed in the form of a practical diagnostic system titled "Brain Profiling". Three dimensions make-up brain profiling, "neural complexity disorders", "neuronal resilience insufficiency", and "context-sensitive processing decline". The first dimension relates to disturbances occurring to fast neuronal activations in the millisecond range, it incorporates connectivity and hierarchical imbalances appertaining typically to psychotic and schizophrenic clinical manifestations. The second dimension relates to disturbances that alter slower changes namely long-term synaptic modulations, and incorporates disturbances to optimization and constraint satisfactions within relevant neuronal circuitry. Finally, the level of internal representations related to personality disorders is presented by a "context-sensitive process decline" as the third dimension. For practical use of brain profiling diagnosis a consensual list of psychiatric clinical manifestations provides a "diagnostic input vector", clinical findings are coded 1 for "detection" and 0 for "non-detection", 0.5 is coded for "questionable". The entries are clustered according to their presumed neuronal dynamic relationships and coefficients determine their relevance to the specific related brain disturbance. Relevant equations calculate and normalize the different values attributed to relevant brain disturbances culminating in a three-digit estimation representing the three diagnostic dimensions. brain profiling has the promise for a future brain-related diagnosis. It offers testable predictions about the etiology of mental disorders because being brain-related it lends readily to brain imaging investigations. Being presented also as a one-point representation in a three-dimensional space, multiple follow-up diagnoses trace a trajectory representing an easy-to-see clinical history of the patient. Additional, more immediate, advantages involve reduced stigma because it relaters the disorder to the brain not the person, in addition the three-digit diagnostic code is clinically informative unlike the DSM codes that have no clinical relevance. To conclude, brain profiling diagnosis of mental disorders could be a bold new step toward a "clinical-neuroscience" substituting "psychiatry".

Joint statistics of strongly correlated neurons via dimensionality reduction

NASA Astrophysics Data System (ADS)

Deniz, Taşkın; Rotter, Stefan

2017-06-01

The relative timing of action potentials in neurons recorded from local cortical networks often shows a non-trivial dependence, which is then quantified by cross-correlation functions. Theoretical models emphasize that such spike train correlations are an inevitable consequence of two neurons being part of the same network and sharing some synaptic input. For non-linear neuron models, however, explicit correlation functions are difficult to compute analytically, and perturbative methods work only for weak shared input. In order to treat strong correlations, we suggest here an alternative non-perturbative method. Specifically, we study the case of two leaky integrate-and-fire neurons with strong shared input. Correlation functions derived from simulated spike trains fit our theoretical predictions very accurately. Using our method, we computed the non-linear correlation transfer as well as correlation functions that are asymmetric due to inhomogeneous intrinsic parameters or unequal input.

Atomic Calculations and Laboratory Measurements Relevant to X-ray Warm Absorbers

NASA Technical Reports Server (NTRS)

Kallman, Tim; Bautista, M.; Palmeri, P.

2007-01-01

This viewgraph document reviews the atomic calculations and the measurements from the laboratory that are relevant to our understanding of X-Ray Warm Absorbers. Included is a brief discussion of the theoretical and the experimental tools. Also included is a discussion of the challenges, and calculations relevant to dielectronic recombination, photoionization cross sections, and collisional ionization. A review of the models is included, and the sequence that the models were applied.

Caprylate Salts Based on Amines as Volatile Corrosion Inhibitors for Metallic Zinc: Theoretical and Experimental Studies

PubMed Central

Valente, Marco A. G.; Teixeira, Deiver A.; Azevedo, David L.; Feliciano, Gustavo T.; Benedetti, Assis V.; Fugivara, Cecílio S.

2017-01-01

The interaction of volatile corrosion inhibitors (VCI), caprylate salt derivatives from amines, with zinc metallic surfaces is assessed by density functional theory (DFT) computer simulations, electrochemical impedance (EIS) measurements and humid chamber tests. The results obtained by the different methods were compared, and linear correlations were obtained between theoretical and experimental data. The correlations between experimental and theoretical results showed that the molecular size is the determining factor in the inhibition efficiency. The models used and experimental results indicated that dicyclohexylamine caprylate is the most efficient inhibitor. PMID:28620602

The validity of different measures of automatic alcohol action tendencies.

PubMed

Kersbergen, Inge; Woud, Marcella L; Field, Matt

2015-03-01

Previous studies have demonstrated that automatic alcohol action tendencies are related to alcohol consumption and hazardous drinking. These action tendencies are measured with reaction time tasks in which the latency to make an approach response to alcohol pictures is compared with the latency to make an avoidance response. In the literature, 4 different tasks have been used, and these tasks differ on whether alcohol is a relevant (R) or irrelevant (IR) feature for categorization and on whether participants must make a symbolic approach response (stimulus-response compatibility [SRC] tasks) or an overt behavioral response (approach avoidance tasks [AAT]) to the pictures. Previous studies have shown positive correlations between measures of action tendencies and hazardous drinking and weekly alcohol consumption. However, results have been inconsistent and the different measures have not been directly compared with each other. Therefore, it is unclear which task is the best predictor of hazardous drinking and alcohol consumption. In the present study, 80 participants completed all 4 measures of action tendencies (i.e., R-SRC, IR-SRC, R-AAT, and IR-AAT) and measures of alcohol consumption and hazardous drinking. Stepwise regressions showed that the R-SRC and R-AAT were the only significant predictors of hazardous drinking, whereas the R-AAT was the only reliable predictor of alcohol consumption. Our results confirm that drinking behavior is positively correlated with automatic alcohol approach tendencies, but only if alcohol-relatedness is the relevant feature for categorization. Theoretical implications and methodological issues are discussed. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Contextual factors associated with eating in the absence of hunger among adults with obesity.

PubMed

Goldschmidt, Andrea B; Crosby, Ross D; Cao, Li; Pearson, Carolyn M; Utzinger, Linsey M; Pacanowski, Carly R; Mason, Tyler B; Berner, Laura A; Engel, Scott G; Wonderlich, Stephen A; Peterson, Carol B

2017-08-01

Eating in the absence of hunger (EAH) is under-explored in adults with obesity. In this study, 50 adults with obesity recorded eating episodes and theoretically-relevant environmental, perceptual, and emotional correlates in the natural environment for 2weeks via ecological momentary assessment (EMA). Generalized linear models and mixed models were used to characterize correlates and consequences of EAH vs. non-EAH episodes/tendencies (within-subjects and between-subjects effects, respectively), time of day, and time of day×EAH interactions. Approximately 21% of EMA-recorded eating episodes involved EAH, and 70% of participants reported at least 1 EAH episode. At the within-person level, participants' EAH episodes were associated with greater self-labeled overeating than their non-EAH episodes. At the between-person level, participants who tended to engage in more EAH reported less self-labeled overeating than those who engaged in less EAH. Across EAH and non-EAH episodes, eating in the evening was associated with overeating, expecting eating to be more rewarding, greater alcoholic beverage consumption, eating alone, eating because others are eating, and eating while watching television. Significant EAH×time of day interactions were also observed but the pattern of findings was not consistent. Findings suggest that EAH may be a relevant target for reducing food intake in individuals with obesity given its high prevalence and association with perceptions of overeating, although results should be extended using objective measures of food intake. Associations between evening eating episodes and perceptual and environmental factors should be further explored. Copyright © 2017. Published by Elsevier Ltd.

Exceptional know how? Possible pitfalls of routinising genetic services.

PubMed

Schmitz, Dagmar

2010-09-01

Genetic testing practices are increasingly advancing clinical medicine. This process of 'routinisation of genetics' has been conceived as a medical and ethical problem mainly because of the assumption that non-geneticists might lack the necessary skills to provide these services. In particular, the relevant theoretical knowledge in clinical genetics is viewed as insufficient in general practitioners and physicians from other specialities. Empirical findings seem to indicate significant variations not only in theoretical but also in practical knowledge between geneticists and non-geneticists. Several fields of practical knowledge-regarding for example the focus of clinical action, the relevance of therapeutic action or the normative framework-can be identified that are or could be areas of conflict when the routinisation of genetic services proceeds. From an ethical point of view, these variations in know how and background are especially relevant whenever the respective genetic service is concerned with medical information of exceptional normative quality, such as, for example, in prenatal genetic screening and diagnosis of untreatable conditions. Here, the clinically acquired practical knowledge of the non-geneticist could be particularly misleading insofar as there is no relation to therapy and-in a narrow sense-no clinical utility to be assessed. Non-geneticists need a chance to acquire the relevant theoretical and practical knowledge in order to understand and fulfil their own duties in the respective situations in a way that secures the important rights at stake of their patients and clients.

Library and Information Professionals as Knowledge Engagement Specialists. Theories, Competencies and Current Educational Possibilities in Accredited Graduate Programmes

ERIC Educational Resources Information Center

Prado, Javier Calzada; Marzal, Miguel Angel

2013-01-01

Introduction: The role of library and information science professionals as knowledge facilitators is solidly grounded in the profession's theoretical foundations as much as connected with its social relevance. Knowledge science is presented in this paper as a convenient theoretical framework for this mission, and knowledge engagement…

Learning Terminology in Order to Become an Active Agent in the Development of Basque Biomedical Registers

ERIC Educational Resources Information Center

Zabala Unzalu, Igone; San Martin Egia, Itziar; Lersundi Ayestaran, Mikel

2016-01-01

The aim of this article is to describe some theoretical and methodological bases underpinning the design of the course Health Communication in Basque (HCB) at the University of the Basque Country (UPV/EHU). Based on some relevant theoretical tenets of the socioterminologic and communicative approaches to Terminology, the authors assume that…

The Effects of Social Injustice and Inequality on Children's Moral Judgments and Behavior: Towards a Theoretical Model

ERIC Educational Resources Information Center

Arsenio, William F.; Gold, Jason

2006-01-01

Our goal in this paper is to examine the potential origins of children's understanding of morally relevant transgressions, with a particular focus on how children's perceptions of both proximal and distal unfairness might influence their social reasoning and behavior. A preliminary theoretical model is presented that addresses connections among…

(Fundamental of hadron physics from the theoretical and the experimental points of view)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luccio, A.

1991-02-19

A winter course at a School of Nuclear Physics was organized by the Italian Government Agency INFN. Lectures included fundamental of Hadron Physics from the theoretical and the experimental points of view. The present traveler was invited to hold a course on relevant accelerator physics. All expenses were paid by the Italians.

Moving from Good Ideas in Educational Systems Change to Sustainable Program Implementation: Coming to Terms with Some of the Realities

ERIC Educational Resources Information Center

Noell, George H.; Gansle, Kristin A.

2009-01-01

Proponents of systemic changes in education commonly encounter ethical, theoretical, and pragmatic challenges in moving from possibility to implementation of their vision of change. Although ethical and theoretical issues are critically important to a successful change initiative, pragmatic issues relevant to assuring program implementation have…

Rapid estimation of the electron correlation energy for van der Waals complexes RgX (Rg = Kr, Xe, X = Br, I)

NASA Astrophysics Data System (ADS)

Xinying, Li; Yongfang, Zhao; Xiaogong, Jing; Fengli, Liu; Fengyou, Hao

2006-01-01

We present the rules of electron correlation energies for RgX (Rg = Kr, Xe, X = Br, I) van der Waals (vdW) complex systems at CCSD(T) theoretical level with SDB-cc-pVQZ basis set by the Gaussian 98 program. A new method to derive the dispersion coefficient C6 by fitting the intermonomer electron correlation energies to C6R-6 function is introduced. The present C6 values are compared with the corresponding theoretical ones.

U.S. Comparative and International Graduate Programs: An Overview of Programmatic Size, Relevance, Philosophy, and Methodology

ERIC Educational Resources Information Center

Drake, Timothy A.

2011-01-01

Previous work has concentrated on the epistemological foundation of comparative and international education (CIE) graduate programs. This study focuses on programmatic size, philosophy, methodology, and pedagogy. It begins by reviewing previous studies. It then provides a theoretical framework and describes the size, relevance, content, and…

The Causal Effects of Cultural Relevance: Evidence from an Ethnic Studies Curriculum. CEPA Working Paper No. 16-01

ERIC Educational Resources Information Center

Dee, Thomas; Penner, Emily

2016-01-01

An extensive theoretical and qualitative literature stresses the promise of instructional practices and content aligned with the cultural experiences of minority students. Ethnic studies courses provide a growing but controversial example of such "culturally relevant pedagogy." However, the empirical evidence on the effectiveness of…

Slower Reacquisition after Partial Extinction in Human Contingency Learning

ERIC Educational Resources Information Center

Morís, Joaquín; Barberia, Itxaso; Vadillo, Miguel A.; Andrades, Ainhoa; López, Francisco J.

2017-01-01

Extinction is a very relevant learning phenomenon from a theoretical and applied point of view. One of its most relevant features is that relapse phenomena often take place once the extinction training has been completed. Accordingly, as extinction-based therapies constitute the most widespread empirically validated treatment of anxiety disorders,…

The Advisor as Servant: The Theoretical and Philosophical Relevance of Servant Leadership to Academic Advising

ERIC Educational Resources Information Center

McClellan, Jeffrey L.

2007-01-01

Servant. This novel actively portrays Greenleaf's concept of servant leadership by describing the extracurricular work of a university professor. Consequently, some scholars have demonstrated the relevance of servant leadership to classroom instruction (Powers & Moore, 2005). However, it was not as an instructor, but as an advisor that the…

Understanding bimolecular machines: Theoretical and experimental approaches

NASA Astrophysics Data System (ADS)

Goler, Adam Scott

This dissertation concerns the study of two classes of molecular machines from a physical perspective: enzymes and membrane proteins. Though the functions of these classes of proteins are different, they each represent important test-beds from which new understanding can be developed by the application of different techniques. HIV1 Reverse Transcriptase is an enzyme that performs multiple functions, including reverse transcription of RNA into an RNA/DNA duplex, RNA degradation by the RNaseH domain, and synthesis of dsDNA. These functions allow for the incorporation of the retroviral genes into the host genome. Its catalytic cycle requires repeated large-scale conformational changes fundamental to its mechanism. Motivated by experimental work, these motions were studied theoretically by the application of normal mode analysis. It was observed that the lowest order modes correlate with largest amplitude (low-frequency) motion, which are most likely to be catalytically relevant. Comparisons between normal modes obtained via an elastic network model to those calculated from the essential dynamics of a series of all-atom molecular dynamics simulations show the self-consistency between these calculations. That similar conformational motions are seen between independent theoretical methods reinforces the importance of large-scale subdomain motion for the biochemical action of DNA polymerases in general. Moreover, it was observed that the major subunits of HIV1 Reverse Transcriptase interact quasi-harmonically. The 5HT3A Serotonin receptor and P2X1 receptor, by contrast, are trans-membrane proteins that function as ligand gated ion channels. Such proteins feature a central pore, which allows for the transit of ions necessary for cellular function across a membrane. The pore is opened by the ligation of binding sites on the extracellular portion of different protein subunits. In an attempt to resolve the individual subunits of these membrane proteins beyond the diffraction limit, a super-localization microscope capable of reconstructing super-resolution images was constructed. This novel setup allows for the study of discrete state kinetic mechanisms with spatial resolution good enough to distinguish individual binding sites of these membrane proteins. Further use of this technique may allow for the study of allostery and subunit specific stoichiometry in the presence of agonist or antagonist ligands relevant to pharmacology.

Mapping the current–current correlation function near a quantum critical point

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prodan, Emil, E-mail: prodan@yu.edu; Bellissard, Jean

2016-05-15

The current–current correlation function is a useful concept in the theory of electron transport in homogeneous solids. The finite-temperature conductivity tensor as well as Anderson’s localization length can be computed entirely from this correlation function. Based on the critical behavior of these two physical quantities near the plateau–insulator or plateau–plateau transitions in the integer quantum Hall effect, we derive an asymptotic formula for the current–current correlation function, which enables us to make several theoretical predictions about its generic behavior. For the disordered Hofstadter model, we employ numerical simulations to map the current–current correlation function, obtain its asymptotic form near amore » critical point and confirm the theoretical predictions.« less

A cross-country comparison of intensive care physicians' beliefs about their transfusion behaviour: a qualitative study using the Theoretical Domains Framework.

PubMed

Islam, Rafat; Tinmouth, Alan T; Francis, Jill J; Brehaut, Jamie C; Born, Jennifer; Stockton, Charlotte; Stanworth, Simon J; Eccles, Martin P; Cuthbertson, Brian H; Hyde, Chris; Grimshaw, Jeremy M

2012-09-21

Evidence of variations in red blood cell transfusion practices have been reported in a wide range of clinical settings. Parallel studies in Canada and the United Kingdom were designed to explore transfusion behaviour in intensive care physicians. The aim of this paper is three-fold: first, to explore beliefs that influence Canadian intensive care physicians' transfusion behaviour; second, to systematically select relevant theories and models using the Theoretical Domains Framework (TDF) to inform a future predictive study; and third, to compare its results with the UK study. Ten intensive care unit (ICU) physicians throughout Canada were interviewed. Physicians' responses were coded into theoretical domains, and specific beliefs were generated for each response. Theoretical domains relevant to behaviour change were identified, and specific constructs from the relevant domains were used to select psychological theories. The results from Canada and the United Kingdom were compared. Seven theoretical domains populated by 31 specific beliefs were identified as relevant to the target behaviour. The domains Beliefs about capabilities (confident to not transfuse if patients' clinical condition is stable), Beliefs about consequences (positive beliefs of reducing infection and saving resources and negative beliefs about risking patients' clinical outcome and potentially more work), Social influences (transfusion decision is influenced by team members and patients' relatives), and Behavioural regulation (wide range of approaches to encourage restrictive transfusion) that were identified in the UK study were also relevant in the Canadian context. Three additional domains, Knowledge (it requires more evidence to support restrictive transfusion), Social/professional role and identity (conflicting beliefs about not adhering to guidelines, referring to evidence, believing restrictive transfusion as professional standard, and believing that guideline is important for other professionals), and Motivation and goals (opposing beliefs about the importance of restrictive transfusion and compatibility with other goals), were also identified in this study. Similar to the UK study, the Theory of Planned Behaviour, Social Cognitive Theory, Operant Learning Theory, Action Planning, and Knowledge-Attitude-Behaviour model were identified as potentially relevant theories and models for further study. Personal project analysis was added to the Canadian study to explore the Motivation and goals domain in further detail. A wide range of beliefs was identified by the Canadian ICU physicians as likely to influence their transfusion behaviour. We were able to demonstrate similar though not identical results in a cross-country comparison. Designing targeted behaviour-change interventions based on unique beliefs identified by physicians from two countries are more likely to encourage restrictive transfusion in ICU physicians in respective countries. This needs to be tested in future prospective clinical trials.

A cross-country comparison of intensive care physicians’ beliefs about their transfusion behaviour: A qualitative study using the theoretical domains framework

PubMed Central

2012-01-01

Background Evidence of variations in red blood cell transfusion practices have been reported in a wide range of clinical settings. Parallel studies in Canada and the United Kingdom were designed to explore transfusion behaviour in intensive care physicians. The aim of this paper is three-fold: first, to explore beliefs that influence Canadian intensive care physicians’ transfusion behaviour; second, to systematically select relevant theories and models using the Theoretical Domains Framework (TDF) to inform a future predictive study; and third, to compare its results with the UK study. Methods Ten intensive care unit (ICU) physicians throughout Canada were interviewed. Physicians’ responses were coded into theoretical domains, and specific beliefs were generated for each response. Theoretical domains relevant to behaviour change were identified, and specific constructs from the relevant domains were used to select psychological theories. The results from Canada and the United Kingdom were compared. Results Seven theoretical domains populated by 31 specific beliefs were identified as relevant to the target behaviour. The domains Beliefs about capabilities (confident to not transfuse if patients’ clinical condition is stable), Beliefs about consequences (positive beliefs of reducing infection and saving resources and negative beliefs about risking patients’ clinical outcome and potentially more work), Social influences (transfusion decision is influenced by team members and patients’ relatives), and Behavioural regulation (wide range of approaches to encourage restrictive transfusion) that were identified in the UK study were also relevant in the Canadian context. Three additional domains, Knowledge (it requires more evidence to support restrictive transfusion), Social/professional role and identity (conflicting beliefs about not adhering to guidelines, referring to evidence, believing restrictive transfusion as professional standard, and believing that guideline is important for other professionals), and Motivation and goals (opposing beliefs about the importance of restrictive transfusion and compatibility with other goals), were also identified in this study. Similar to the UK study, the Theory of Planned Behaviour, Social Cognitive Theory, Operant Learning Theory, Action Planning, and Knowledge-Attitude-Behaviour model were identified as potentially relevant theories and models for further study. Personal project analysis was added to the Canadian study to explore the Motivation and goals domain in further detail. Conclusions A wide range of beliefs was identified by the Canadian ICU physicians as likely to influence their transfusion behaviour. We were able to demonstrate similar though not identical results in a cross-country comparison. Designing targeted behaviour-change interventions based on unique beliefs identified by physicians from two countries are more likely to encourage restrictive transfusion in ICU physicians in respective countries. This needs to be tested in future prospective clinical trials. PMID:22999460

Photon scattering cross sections of H2 and He measured with synchrotron radiation

NASA Technical Reports Server (NTRS)

Ice, G. E.

1977-01-01

Total (elastic + inelastic) differential photon scattering cross sections have been measured for H2 gas and He, using an X-ray beam. Absolute measured cross sections agree with theory within the probable errors. Relative cross sections (normalized to theory at large S) agree to better than one percent with theoretical values calculated from wave functions that include the effect of electron-electron Coulomb correlation, but the data deviate significantly from theoretical independent-particle (e.g., Hartree-Fock) results. The ratios of measured absolute He cross sections to those of H2, at any given S, also agree to better than one percent with theoretical He-to-H2 cross-section ratios computed from correlated wave functions. It appears that photon scattering constitutes a very promising tool for probing electron correlation in light atoms and molecules.

Risk/Benefit Communication about Food-A Systematic Review of the Literature.

PubMed

Frewer, L J; Fischer, A R H; Brennan, M; Bánáti, D; Lion, R; Meertens, R M; Rowe, G; Siegrist, M; Verbeke, W; Vereijken, C M J L

2016-07-26

A systematic review relevant to the following research questions was conducted (1) the extent to which different theoretical frameworks have been applied to food risk/benefit communication and (2) the impact such food risk/benefit communication interventions have had on related risk/benefit attitudes and behaviors. Fifty four papers were identified. The analysis revealed that (primarily European or US) research interest has been relatively recent. Certain food issues were of greater interest to researchers than others, perhaps reflecting the occurrence of a crisis, or policy concern. Three broad themes relevant to the development of best practice in risk (benefit) communication were identified: the characteristics of the target population; the contents of the information; and the characteristics of the information sources. Within these themes, independent and dependent variables differed considerably. Overall, acute risk (benefit) communication will require advances in communication process whereas chronic communication needs to identify audience requirements. Both citizen's risk/benefit perceptions and (if relevant) related behaviors need to be taken into account, and recommendations for behavioral change need to be concrete and actionable. The application of theoretical frameworks to the study of risk (benefit) communication was infrequent, and developing predictive models of effective risk (benefit) communication may be contingent on improved theoretical perspectives.

Cognitive vulnerability to depression during middle childhood: Stability and associations with maternal affective styles and parental depression

PubMed Central

Hayden, Elizabeth P.; Olino, Thomas M.; Mackrell, Sarah V.M.; Jordan, Patricia L.; Desjardins, Jasmine; Katsiroumbas, Patrice

2014-01-01

Theories of cognitive vulnerability to depression (CVD) imply that CVD is early-emerging and trait-like; however, little longitudinal work has tested this premise in middle childhood, or examined theoretically relevant predictors of child CVD. We examined test–retest correlations of self-referent encoding task performance and self-reported attributional styles and their associations with parental characteristics in 205 seven-year-olds. At baseline, child CVD was assessed, structured clinical interviews were conducted with parents, and ratings of observed maternal affective styles were made. Children’s CVD was re-assessed approximately one and two years later. Both measures of children’s CVD were prospectively and concurrently associated with children’s depressive symptoms and showed modest stability. Multilevel modeling indicated that maternal criticism and paternal depression were related to children’s CVD. Findings indicate that even early-emerging CVD is a valid marker of children’s depression risk. PMID:25392596

Micro-bubbles and Micro-particles are Not Faithful Tracers of Turbulent Acceleration

NASA Astrophysics Data System (ADS)

Sun, Chao; Mathai, Varghese; Calzavarini, Enrico; Brons, Jon; Lohse, Detlef

2016-11-01

We report on the Lagrangian statistics of acceleration of small (sub-Kolmogorov) bubbles and tracer particles with Stokes number St <<1 in turbulent flow. At decreasing Reynolds number, the bubble accelerations show deviations from that of tracer particles, i.e. they deviate from the Heisenberg-Yaglom prediction and show a quicker decorrelation despite their small size and minute St. Using direct numerical simulations, we show that these effects arise due the drift of these particles through the turbulent flow. We theoretically predict this gravity-driven effect for developed isotropic turbulence, with the ratio of Stokes to Froude number or equivalently the particle drift-velocity governing the enhancement of acceleration variance and the reductions in correlation time and intermittency. Our predictions are in good agreement with experimental and numerical results. The present findings are relevant to a range of scenarios encompassing tiny bubbles and droplets that drift through the turbulent oceans and the atmosphere.

Biophysical Properties of Plasmodium falciparum-Infected Erythrocytes from Novel Analysis of the Flicker Phenomena

NASA Astrophysics Data System (ADS)

Arie, Takayuki; Jin, Albert; Dvorak, James

2002-03-01

Infectious processes often modulate the intrinsic properties of vertebrate cells. We studied the modulation of human erythrocyte flicker during the intra-erythrocytic cycle of Plasmodium falciparum malaria using video microscopy imaging and a data analysis system of our design to extract flicker spectra and lateral cell edge undulations of individual erythrocytes at various stages of infection. The total flicker power, the power weighted mean flicker frequency, the mode amplitudes of lateral undulations, and the time correlation of translation mode was quantified by infectious stage and modeled theoretically. Our results suggest that malaria-infected erythrocytes become increasingly more rigid following infection and provide an insight into the modulation of erythrocyte cytoplasmic viscosity by the parasites. These studies of malaria-infected erythrocytes elucidate the kinetics of both membrane and cellular changes that are relevant to blood microcirculation and improve our understanding of the malaria disease process.

Power in everyday life

PubMed Central

Hofmann, Wilhelm

2016-01-01

How does power manifest itself in everyday life? Using experience-sampling methodology, we investigated the prevalence, sources, and correlates of power in people’s natural environments. Participants experienced power-relevant situations regularly, though not frequently. High power was not restricted to a limited few: almost half of the sample reported experiencing high-power positions. Positional power and subjective feelings of power were strongly related but had unique relations with several individual difference measures and independent effects on participants’ affect, cognition, and interpersonal relations. Subjective feelings of power resulted more from within-participant situational fluctuation, such as the social roles participants held at different times, than from stable differences between people. Our data supported some theoretical predictions about power’s effects on affect, cognition, and interpersonal relations, but qualified others, particularly highlighting the role of responsibility in power’s effects. Although the power literature has focused on high power, we found stronger effects of low power than high power. PMID:27551069

Power in everyday life.

PubMed

Smith, Pamela K; Hofmann, Wilhelm

2016-09-06

How does power manifest itself in everyday life? Using experience-sampling methodology, we investigated the prevalence, sources, and correlates of power in people's natural environments. Participants experienced power-relevant situations regularly, though not frequently. High power was not restricted to a limited few: almost half of the sample reported experiencing high-power positions. Positional power and subjective feelings of power were strongly related but had unique relations with several individual difference measures and independent effects on participants' affect, cognition, and interpersonal relations. Subjective feelings of power resulted more from within-participant situational fluctuation, such as the social roles participants held at different times, than from stable differences between people. Our data supported some theoretical predictions about power's effects on affect, cognition, and interpersonal relations, but qualified others, particularly highlighting the role of responsibility in power's effects. Although the power literature has focused on high power, we found stronger effects of low power than high power.

Unified theory of inertial granular flows and non-Brownian suspensions.

PubMed

DeGiuli, E; Düring, G; Lerner, E; Wyart, M

2015-06-01

Rheological properties of dense flows of hard particles are singular as one approaches the jamming threshold where flow ceases both for aerial granular flows dominated by inertia and for over-damped suspensions. Concomitantly, the length scale characterizing velocity correlations appears to diverge at jamming. Here we introduce a theoretical framework that proposes a tentative, but potentially complete, scaling description of stationary flows. Our analysis, which focuses on frictionless particles, applies both to suspensions and inertial flows of hard particles. We compare our predictions with the empirical literature, as well as with novel numerical data. Overall, we find a very good agreement between theory and observations, except for frictional inertial flows whose scaling properties clearly differ from frictionless systems. For overdamped flows, more observations are needed to decide if friction is a relevant perturbation. Our analysis makes several new predictions on microscopic dynamical quantities that should be accessible experimentally.

A multidimensional approach to measuring well-being in students: Application of the PERMA framework

PubMed Central

Kern, Margaret L.; Waters, Lea E.; Adler, Alejandro; White, Mathew A.

2015-01-01

Seligman recently introduced the PERMA model with five core elements of psychological well-being: positive emotions, engagement, relationships, meaning, and accomplishment. We empirically tested this multidimensional theory with 516 Australian male students (age 13–18). From an extensive well-being assessment, we selected a subset of items theoretically relevant to PERMA. Factor analyses recovered four of the five PERMA elements, and two ill-being factors (depression and anxiety). We then explored the nomological net surrounding each factor by examining cross-sectional associations with life satisfaction, hope, gratitude, school engagement, growth mindset, spirituality, physical vitality, physical activity, somatic symptoms, and stressful life events. Factors differentially related to these correlates, offering support for the multidimensional approach to measuring well-being. Directly assessing subjective well-being across multiple domains offers the potential for schools to more systematically understand and promote well-being. PMID:25745508

Multi-boson block factorization of fermions

NASA Astrophysics Data System (ADS)

Giusti, Leonardo; Cè, Marco; Schaefer, Stefan

2018-03-01

The numerical computations of many quantities of theoretical and phenomenological interest are plagued by statistical errors which increase exponentially with the distance of the sources in the relevant correlators. Notable examples are baryon masses and matrix elements, the hadronic vacuum polarization and the light-by-light scattering contributions to the muon g - 2, and the form factors of semileptonic B decays. Reliable and precise determinations of these quantities are very difficult if not impractical with state-of-the-art standard Monte Carlo integration schemes. I will review a recent proposal for factorizing the fermion determinant in lattice QCD that leads to a local action in the gauge field and in the auxiliary boson fields. Once combined with the corresponding factorization of the quark propagator, it paves the way for multi-level Monte Carlo integration in the presence of fermions opening new perspectives in lattice QCD. Exploratory results on the impact on the above mentioned observables will be presented.

Winners, Losers, Insiders, and Outsiders: Comparing Hierometer and Sociometer Theories of Self-Regard

PubMed Central

Mahadevan, Nikhila; Gregg, Aiden P.; Sedikides, Constantine; de Waal-Andrews, Wendy G.

2016-01-01

What evolutionary function does self-regard serve? Hierometer theory, introduced here, provides one answer: it helps individuals navigate status hierarchies, which feature zero-sum contests that can be lost as well as won. In particular, self-regard tracks social status to regulate behavioral assertiveness, augmenting or diminishing it to optimize performance in such contests. Hierometer theory also offers a conceptual counterpoint that helps resolve ambiguities in sociometer theory, which offers a complementary account of self-regard’s evolutionary function. In two large-scale cross-sectional studies, we operationalized theoretically relevant variables at three distinct levels of analysis, namely, social (relations: status, inclusion), psychological (self-regard: self-esteem, narcissism), and behavioral (strategy: assertiveness, affiliativeness). Correlational and mediational analyses consistently supported hierometer theory, but offered only mixed support for sociometer theory, including when controlling for confounding constructs (anxiety, depression). We interpret our results in terms of a broader agency-communion framework. PMID:27065896

UV absorption in metal decorated boron nitride flakes: a theoretical analysis of excited states

NASA Astrophysics Data System (ADS)

Chopra, Siddheshwar; Plasser, Felix

2017-10-01

The excited states of single metal atom (X = Co, Al and Cu) doped boron nitride flake (MBNF) B15N14H14-X and pristine boron nitride (B15N15H14) are studied by time-dependent density functional theory. The immediate effect of metal doping is a red shift of the onset of absorption from about 220 nm for pristine BNF to above 300 nm for all metal-doped variants with the biggest effect for MBNF-Co, which shows appreciable intensity even above 400 nm. These energy shifts are analysed by detailed wavefunction analysis protocols using visualisation methods, such as the natural transition orbital analysis and electron-hole correlation plots, as well as quantitative analysis of the exciton size and electron-hole populations. The analysis shows that the Co and Cu atoms provide strong contributions to the relevant states whereas the aluminium atom is only involved to a lesser extent.

Continuous microalgal cultivation in a laboratory-scale photobioreactor under seasonal day-night irradiation: experiments and simulation.

PubMed

Bertucco, Alberto; Beraldi, Mariaelena; Sforza, Eleonora

2014-08-01

In this work, the production of Scenedesmus obliquus in a continuous flat-plate laboratory-scale photobioreactor (PBR) under alternated day-night cycles was tested both experimentally and theoretically. Variation of light intensity according to the four seasons of the year were simulated experimentally by a tunable LED lamp, and effects on microalgal growth and productivity were measured to evaluate the conversion efficiency of light energy into biomass during the different seasons. These results were used to validate a mathematical model for algae growth that can be applied to simulate a large-scale production unit, carried out in a flat-plate PBR of similar geometry. The cellular concentration in the PBR was calculated in both steady-state and transient conditions, and the value of the maintenance kinetic term was correlated to experimental profiles. The relevance of this parameter was finally outlined.

Military sexual trauma research: a proposed agenda.

PubMed

Allard, Carolyn B; Nunnink, Sarah; Gregory, Amber M; Klest, Bridget; Platt, Melissa

2011-01-01

Military sexual trauma (MST) is a widespread problem associated with negative psychological and physical health problems. This article presents the current state of MST research and highlights specific areas in need of more focused study. Areas that have produced the greatest body of knowledge include MST prevalence and psychological and physical health correlates. We propose a research agenda based on gaps noted in our research review and empirical and theoretical evidence of issues relevant to but not studied directly in MST populations. We present evidence that MST is qualitatively distinct from other forms of sexual maltreatment in terms of its relational and vocational context as well as the severity of associated psychological distress, examine underexplored gender and sexual issues in MST, and discuss the lack of treatment and prevention studies specific to MST. Specific recommendations are made throughout in an attempt to guide and advance the field.

Two-dimensional adaptation in the auditory forebrain

PubMed Central

Nagel, Katherine I.; Doupe, Allison J.

2011-01-01

Sensory neurons exhibit two universal properties: sensitivity to multiple stimulus dimensions, and adaptation to stimulus statistics. How adaptation affects encoding along primary dimensions is well characterized for most sensory pathways, but if and how it affects secondary dimensions is less clear. We studied these effects for neurons in the avian equivalent of primary auditory cortex, responding to temporally modulated sounds. We showed that the firing rate of single neurons in field L was affected by at least two components of the time-varying sound log-amplitude. When overall sound amplitude was low, neural responses were based on nonlinear combinations of the mean log-amplitude and its rate of change (first time differential). At high mean sound amplitude, the two relevant stimulus features became the first and second time derivatives of the sound log-amplitude. Thus a strikingly systematic relationship between dimensions was conserved across changes in stimulus intensity, whereby one of the relevant dimensions approximated the time differential of the other dimension. In contrast to stimulus mean, increases in stimulus variance did not change relevant dimensions, but selectively increased the contribution of the second dimension to neural firing, illustrating a new adaptive behavior enabled by multidimensional encoding. Finally, we demonstrated theoretically that inclusion of time differentials as additional stimulus features, as seen so prominently in the single-neuron responses studied here, is a useful strategy for encoding naturalistic stimuli, because it can lower the necessary sampling rate while maintaining the robustness of stimulus reconstruction to correlated noise. PMID:21753019

A New Measure to Assess Psychopathic Personality in Children: The Child Problematic Traits Inventory.

PubMed

Colins, Olivier F; Andershed, Henrik; Frogner, Louise; Lopez-Romero, Laura; Veen, Violaine; Andershed, Anna-Karin

2014-01-01

Understanding the development of psychopathic personality from childhood to adulthood is crucial for understanding the development and stability of severe and long-lasting conduct problems and criminal behavior. This paper describes the development of a new teacher rated instrument to assess psychopathic personality from age three to 12, the Child Problematic Traits Inventory (CPTI). The reliability and validity of the CPTI was tested in a Swedish general population sample of 2,056 3- to 5-year-olds (mean age = 3.86; SD = .86; 53 % boys). The CPTI items loaded distinctively on three theoretically proposed factors: a Grandiose-Deceitful Factor, a Callous-Unemotional factor, and an Impulsive-Need for Stimulation factor. The three CPTI factors showed reliability in internal consistency and external validity, in terms of expected correlations with theoretically relevant constructs (e.g., fearlessness). The interaction between the three CPTI factors was a stronger predictor of concurrent conduct problems than any of the three individual CPTI factors, showing that it is important to assess all three factors of the psychopathic personality construct in early childhood. In conclusion, the CPTI seems to reliably and validly assess a constellation of traits that is similar to psychopathic personality as manifested in adolescence and adulthood.

Electronically excited states of vitamin B12 and methylcobalamin: theoretical analysis of absorption, CD, and MCD data.

PubMed

Solheim, Harald; Kornobis, Karina; Ruud, Kenneth; Kozlowski, Pawel M

2011-02-03

Linear and quadratic response time-dependent density functional theory (TD-DFT) has been applied to investigate absorption (Abs), circular dichroism (CD), and magnetic CD (MCD) spectra of cyanocobalamin (CNCbl) and methylcobalamin (MeCbl). Although electronically excited states of both cobalamins have been probed by applying different experimental techniques, their exact nature remains poorly understood from an electronic structure point of view. Recent theoretical studies have revealed a lot of relevant information about their properties but also left some unresolved issues related to the nature of individual transitions. In this contribution, not only Abs but also CD and MCD spectra of both cobalamins were computed for direct comparison with experiment. The results were evaluated with respect to the choice of exchange-correlation functional, basis set, and the environment (gas phase or solvent) used in the calculation. Taking into account the complexity of the CNCbl and MeCbl systems, reliable agreement between theory and experiment was achieved based on calculations employing the BP86 functional, particularly for the low-energy α/β bands. This spectral range has been traditionally interpreted as a vibrational progression associated with a single electronic excitation, but according to the present analysis for both cobalamins, these bands are best interpreted as consisting of multiple electronic transitions.

Application of the finite-field coupled-cluster method to calculate molecular properties relevant to electron electric-dipole-moment searches

NASA Astrophysics Data System (ADS)

Abe, M.; Prasannaa, V. S.; Das, B. P.

2018-03-01

Heavy polar diatomic molecules are currently among the most promising probes of fundamental physics. Constraining the electric dipole moment of the electron (e EDM ), in order to explore physics beyond the standard model, requires a synergy of molecular experiment and theory. Recent advances in experiment in this field have motivated us to implement a finite-field coupled-cluster (FFCC) approach. This work has distinct advantages over the theoretical methods that we had used earlier in the analysis of e EDM searches. We used relativistic FFCC to calculate molecular properties of interest to e EDM experiments, that is, the effective electric field (Eeff) and the permanent electric dipole moment (PDM). We theoretically determine these quantities for the alkaline-earth monofluorides (AEMs), the mercury monohalides (Hg X ), and PbF. The latter two systems, as well as BaF from the AEMs, are of interest to e EDM searches. We also report the calculation of the properties using a relativistic finite-field coupled-cluster approach with single, double, and partial triples' excitations, which is considered to be the gold standard of electronic structure calculations. We also present a detailed error estimate, including errors that stem from our choice of basis sets, and higher-order correlation effects.

Information Theoretic Approaches to Rapid Discovery of Relationships in Large Climate Data Sets

NASA Technical Reports Server (NTRS)

Knuth, Kevin H.; Rossow, William B.; Clancy, Daniel (Technical Monitor)

2002-01-01

Mutual information as the asymptotic Bayesian measure of independence is an excellent starting point for investigating the existence of possible relationships among climate-relevant variables in large data sets, As mutual information is a nonlinear function of of its arguments, it is not beholden to the assumption of a linear relationship between the variables in question and can reveal features missed in linear correlation analyses. However, as mutual information is symmetric in its arguments, it only has the ability to reveal the probability that two variables are related. it provides no information as to how they are related; specifically, causal interactions or a relation based on a common cause cannot be detected. For this reason we also investigate the utility of a related quantity called the transfer entropy. The transfer entropy can be written as a difference between mutual informations and has the capability to reveal whether and how the variables are causally related. The application of these information theoretic measures is rested on some familiar examples using data from the International Satellite Cloud Climatology Project (ISCCP) to identify relation between global cloud cover and other variables, including equatorial pacific sea surface temperature (SST), over seasonal and El Nino Southern Oscillation (ENSO) cycles.

Combined Experimental and Theoretical Investigations on Optical Activities of Möbius Aromatic and Möbius Antiaromatic Hexaphyrin Phosphorus Complexes.

PubMed

Mori, Tadashi; Tanaka, Takayuki; Higashino, Tomohiro; Yoshida, Kota; Osuka, Atsuhiro

2016-06-23

Intrinsically chiral Möbius aromatic [28]hexaphyrin monophosphorus(V) and Möbius antiaromatic [30]hexaphyrin bisphosphorus(V) complexes have been optically resolved and their absolute configurations (ACs) were determined by combined experimental and theoretical investigations on their circular dichroisms (CDs). First elutes in chiral HPLC exhibited strong positive Cotton effects (CEs) at the B-band, characteristic for the ML configurations in their Möbius strips. Weak CEs at the Q-band, if attainable, complemented their AC assignment. The whole CD pattern and intensity were well reproduced by time-dependent approximate coupled cluster theory using model systems that omit five outward meso-aryl substituents (inward-meso-retained model), providing a solid basis for AC assignment. The cost efficient TD-DFT method with appropriate functionals for fully substituted (nontruncated) complexes well reproduced CEs around the B-band (but less satisfactory at the Q-band), also allows the rapid AC estimation for their Möbius strips. Observed difference in CDs between aromatic and antiaromatic hexaphyrins were better interpreted by their shifts in energy levels and altered interactions of relevant molecular orbitals, rather than small differences in Möbius geometries nor aromatic/antiaromatic character, despite the correlations recently claimed in planar π-systems.

How an interacting many-body system tunnels through a potential barrier to open space

PubMed Central

Lode, Axel U.J.; Streltsov, Alexej I.; Sakmann, Kaspar; Alon, Ofir E.; Cederbaum, Lorenz S.

2012-01-01

The tunneling process in a many-body system is a phenomenon which lies at the very heart of quantum mechanics. It appears in nature in the form of α-decay, fusion and fission in nuclear physics, and photoassociation and photodissociation in biology and chemistry. A detailed theoretical description of the decay process in these systems is a very cumbersome problem, either because of very complicated or even unknown interparticle interactions or due to a large number of constituent particles. In this work, we theoretically study the phenomenon of quantum many-body tunneling in a transparent and controllable physical system, an ultracold atomic gas. We analyze a full, numerically exact many-body solution of the Schrödinger equation of a one-dimensional system with repulsive interactions tunneling to open space. We show how the emitted particles dissociate or fragment from the trapped and coherent source of bosons: The overall many-particle decay process is a quantum interference of single-particle tunneling processes emerging from sources with different particle numbers taking place simultaneously. The close relation to atom lasers and ionization processes allows us to unveil the great relevance of many-body correlations between the emitted and trapped fractions of the wave function in the respective processes. PMID:22869703

Generation of non-classical correlated photon pairs via a ladder-type atomic configuration: theory and experiment.

PubMed

Ding, Dong-Sheng; Zhou, Zhi-Yuan; Shi, Bao-Sen; Zou, Xu-Bo; Guo, Guang-Can

2012-05-07

We experimentally generate a non-classical correlated two-color photon pair at 780 and 1529.4 nm in a ladder-type configuration using a hot 85Rb atomic vapor with the production rate of ~10(7)/s. The non-classical correlation between these two photons is demonstrated by strong violation of Cauchy-Schwarz inequality by the factor R = 48 ± 12. Besides, we experimentally investigate the relations between the correlation and some important experimental parameters such as the single-photon detuning, the powers of pumps. We also make a theoretical analysis in detail and the theoretical predictions are in reasonable agreement with our experimental results.

Flow through a very porous obstacle in a shallow channel.

PubMed

Creed, M J; Draper, S; Nishino, T; Borthwick, A G L

2017-04-01

A theoretical model, informed by numerical simulations based on the shallow water equations, is developed to predict the flow passing through and around a uniform porous obstacle in a shallow channel, where background friction is important. This problem is relevant to a number of practical situations, including flow through aquatic vegetation, the performance of arrays of turbines in tidal channels and hydrodynamic forces on offshore structures. To demonstrate this relevance, the theoretical model is used to (i) reinterpret core flow velocities in existing laboratory-based data for an array of emergent cylinders in shallow water emulating aquatic vegetation and (ii) reassess the optimum arrangement of tidal turbines to generate power in a tidal channel. Comparison with laboratory-based data indicates a maximum obstacle resistance (or minimum porosity) for which the present theoretical model is valid. When the obstacle resistance is above this threshold the shallow water equations do not provide an adequate representation of the flow, and the theoretical model over-predicts the core flow passing through the obstacle. The second application of the model confirms that natural bed resistance increases the power extraction potential for a partial tidal fence in a shallow channel and alters the optimum arrangement of turbines within the fence.

Developing a holistic approach to obesity management.

PubMed

Brown, Jenny; Wimpenny, Peter

2011-02-01

The aim of this paper is to discuss the theoretical background and relevance of a holistic approach to obesity management by nurses. There is a global rise in the number of people with obesity, such that it now represents one of the major health challenges. However, nurses are often influenced by physical and dietetic focused approaches and could fail to acknowledge a range of other factors that can impact on weight management. As part of the development of a holistic approach to obesity a literature search was undertaken to establish relevant theoretical perspectives that underpin practice in physical, psychological and social aspects of care (focused on the period 1995-2005). In addition, experiences of working in a secondary care weight management clinic were also drawn upon. Psychobiological, attribution and social support theories were identified that could contribute to a better understanding of obesity. If these theoretical perspectives and supporting evidence can be integrated in a holistic approach to care and management it might be possible to promote better health and well-being in those with obesity. Creating a greater understanding of the range of theoretical perspectives and supporting evidence related to obesity could, it is argued, provide enhanced care and management. © 2011 Blackwell Publishing Asia Pty Ltd.

The Mathematics of Networks Science: Scale-Free, Power-Law Graphs and Continuum Theoretical Analysis

ERIC Educational Resources Information Center

Padula, Janice

2012-01-01

When hoping to initiate or sustain students' interest in mathematics teachers should always consider relevance, relevance to students' lives and in the middle and later years of instruction in high school and university, accessibility. A topic such as the mathematics behind networks science, more specifically scale-free graphs, is up-to-date,…

Polytechnic Engineering Mathematics: Assessing Its Relevance to the Productivity of Industries in Uganda

ERIC Educational Resources Information Center

Jehopio, Peter J.; Wesonga, Ronald

2017-01-01

Background: The main objective of the study was to examine the relevance of engineering mathematics to the emerging industries. The level of abstraction, the standard of rigor, and the depth of theoretical treatment are necessary skills expected of a graduate engineering technician to be derived from mathematical knowledge. The question of whether…

Relevance and Rigor in International Business Teaching: Using the CSA-FSA Matrix

ERIC Educational Resources Information Center

Collinson, Simon C.; Rugman, Alan M.

2011-01-01

We advance three propositions in this paper. First, teaching international business (IB) at any level needs to be theoretically driven, using mainstream frameworks to organize thinking. Second, these frameworks need to be made relevant to the experiences of the students; for example, by using them in case studies. Third, these parameters of rigor…

Correlation among the effective mass (m*), λab and Tc of superconducting cuprates in a Casimir energy scenario

NASA Astrophysics Data System (ADS)

Orlando, M. T. D.; Rouver, A. N.; Rocha, J. R.; Cavichini, A. S.

2018-06-01

The relevance of the Casimir effect, discovered in 1948, has recently been pointed out in studies on materials such as graphene and high-temperature superconducting cuprates. In particular, the relationship between Casimir energy and the energy of a superconducting condensate with anisotropy characterized by high bidimensionality has already been discussed in certain theoretical scenarios. Using this proposal, this work describes the relationship between the effective mass of the charge carriers (m* = αme) and the macroscopic parameters characteristic of several families of high-Tc superconducting cuprates (Cu-HTSC) that have copper and oxygen superconducting planes (Cu-O). We have verified that an expression exists that correlates the effective mass, the London penetration length in the plane λab, the critical temperature Tc and the distance d between the equivalent superconducting planes of Cu-HTSC. This study revealed that the intersection between the asymptotic behavior of α as a function of Tc and the line describing the optimal value of α ≃ 2 (m* ≃ 2me) indicates that a nonadiabatic region exists, which implies a carrier-lattice interaction and where the critical temperature can have its highest value in Cu-HTSC.

The Madrid Affective Database for Spanish (MADS): Ratings of Dominance, Familiarity, Subjective Age of Acquisition and Sensory Experience

PubMed Central

Hinojosa, José A.; Rincón-Pérez, Irene; Romero-Ferreiro, Mª Verónica; Martínez-García, Natalia; Villalba-García, Cristina; Montoro, Pedro R.; Pozo, Miguel A.

2016-01-01

The current study presents ratings by 540 Spanish native speakers for dominance, familiarity, subjective age of acquisition (AoA), and sensory experience (SER) for the 875 Spanish words included in the Madrid Affective Database for Spanish (MADS). The norms can be downloaded as supplementary materials for this manuscript from https://figshare.com/s/8e7b445b729527262c88 These ratings may be of potential relevance to researches who are interested in characterizing the interplay between language and emotion. Additionally, with the aim of investigating how the affective features interact with the lexicosemantic properties of words, we performed correlational analyses between norms for familiarity, subjective AoA and SER, and scores for those affective variables which are currently included in the MADs. A distinct pattern of significant correlations with affective features was found for different lexicosemantic variables. These results show that familiarity, subjective AoA and SERs may have independent effects on the processing of emotional words. They also suggest that these psycholinguistic variables should be fully considered when formulating theoretical approaches to the processing of affective language. PMID:27227521

Examining the psychometric properties of the Barratt Impulsiveness Scale-Brief Form in justice-involved samples.

PubMed

Fields, Sherecce; Edens, John F; Smith, Shannon Toney; Rulseh, Allison; Donnellan, M Brent; Ruiz, Mark A; McDermott, Barbara E; Douglas, Kevin S

2015-12-01

Impulsivity is an important component of many forms of psychopathology. Though widely used as an index of this construct, the 30-item Barratt Impulsiveness Scale-11 (BIS-11) has demonstrated questionable psychometric properties in several research reports. An 8-item shortened version has recently been proposed, the Barratt Impulsiveness Scale-Brief (BIS-Brief) form, which was designed to overcome some of the limitations of the longer scale. In this report, we examine the internal structure and theoretically relevant external correlates of this new short form in large archival samples of individuals involved in the criminal justice system (prison inmates, substance abusers in mandatory treatment, and forensic inpatients). Confirmatory factor analysis of the BIS-Brief indicates adequate fit following a relatively minor modification. Correlations between the BIS-Brief and an array of criterion measures-other self-report scales, interview-based measures, and behavioral outcomes-are consistent with predictions and show relatively little or no decrement in predictive validity when compared with the 30-item BIS-11. Our results suggest that the BIS-Brief is a promising brief measure of impulsivity that evinces good psychometric properties across a range of offender samples. (c) 2015 APA, all rights reserved).

Alcohol Demand, Delayed Reward Discounting, and Craving in relation to Drinking and Alcohol Use Disorders

PubMed Central

MacKillop, James; Miranda, Robert; Monti, Peter M.; Ray, Lara A.; Murphy, James G.; Rohsenow, Damaris J.; McGeary, John E.; Swift, Robert M.; Tidey, Jennifer W.; Gwaltney, Chad J.

2010-01-01

A behavioral economic approach to alcohol use disorders (AUDs) emphasizes both individual and environmental determinants of alcohol use. The current study examined individual differences in alcohol demand (i.e., motivation for alcohol under escalating conditions of price) and delayed reward discounting (i.e., preference for immediate small rewards compared to delayed larger rewards) in 61 heavy drinkers (62% with an AUD). In addition, based on theoretical accounts that emphasize the role of craving in reward valuation and preferences for immediate rewards, craving for alcohol was also examined in relation to these behavioral economic variables and the alcohol-related variables. Intensity of alcohol demand and delayed reward discounting were significantly associated with AUD symptoms, but not with quantitative measures of alcohol use, and were also moderately correlated with each other. Likewise, craving was significantly associated with AUD symptoms, but not with alcohol use, and was also significantly correlated with both intensity of demand and delayed reward discounting. These findings further emphasize the relevance of behavioral economic indices of motivation to alcohol use disorders and the potential importance of craving for alcohol in this relationship. PMID:20141247

Circumstellar chemistry

NASA Technical Reports Server (NTRS)

Glassgold, Alfred E.; Huggins, Patrick J.

1987-01-01

The study of the outer envelopes of cool evolved stars has become an active area of research. The physical properties of CS envelopes are presented. Observations of many wavelengths bands are relevant. A summary of observations and a discussion of theoretical considerations concerning the chemistry are summarized. Recent theoretical considerations show that the thermal equilibrium model is of limited use for understanding the chemistry of the outer CS envelopes. The theoretical modeling of the chemistry of CS envelopes provides a quantitive test of chemical concepts which have a broader interest than the envelopes themselves.

Aortic stiffness improves the prediction of both diagnosis and severity of coronary artery disease.

PubMed

Yannoutsos, Alexandra; Ahouah, Mathieu; Dreyfuss Tubiana, Céline; Topouchian, Jirar; Safar, Michel E; Blacher, Jacques

2018-02-01

Elective coronography has low diagnostic yield for obstructive coronary artery disease (CAD). We aim to determine whether non-invasive aortic stiffness assessment improves diagnostic accuracy of CAD screening by reducing the number of false-positive results from the cardiac stress test. A cross-sectional study was conducted from January 2013 to September 2014 in our medical center. Electrocardiogram (ECG) stress test coupled with nuclear imaging was performed in 367 consecutive patients routinely followed for myocardial ischemia screening. Aortic pulse wave velocity (PWV) was assessed by applanation tonometry in the overall population. Forty-two patients underwent elective coronography because of ischemia. Theoretical PWV was calculated according to age, blood pressure and gender. The results were expressed as an index ((measured PWV-theoretical PWV)/theoretical PWV) for each patient. Ten patients presented with obstructive CAD, 16 patients had non-obstructive CAD and 16 patients had normal coronary angiography. PWV index and severity of CAD were positively correlated (P=0.001). All patients with obstructive CAD had a positive PWV index. When considering the PWV index retrospectively, the false positive results of cardiac stress test were significantly reduced (P<0.001). Twenty-three procedures may have been avoided in the present study cohort. The salient finding of this study was that in patients with known or suspected CAD, routinely followed aortic PWV index may be considered clinically useful for reducing the rate of unnecessary invasive angiographies. The clinical relevance of this individualized decision approach should be confirmed in a large-scale study. Prospective studies have the potential to evaluate the PWV index as a marker of CAD.

Implicit emotion regulation in adolescent girls: An exploratory investigation of Hidden Markov Modeling and its neural correlates.

PubMed

Steele, James S; Bush, Keith; Stowe, Zachary N; James, George A; Smitherman, Sonet; Kilts, Clint D; Cisler, Josh

2018-01-01

Numerous data demonstrate that distracting emotional stimuli cause behavioral slowing (i.e. emotional conflict) and that behavior dynamically adapts to such distractors. However, the cognitive and neural mechanisms that mediate these behavioral findings are poorly understood. Several theoretical models have been developed that attempt to explain these phenomena, but these models have not been directly tested on human behavior nor compared. A potential tool to overcome this limitation is Hidden Markov Modeling (HMM), which is a computational approach to modeling indirectly observed systems. Here, we administered an emotional Stroop task to a sample of healthy adolescent girls (N = 24) during fMRI and used HMM to implement theoretical behavioral models. We then compared the model fits and tested for neural representations of the hidden states of the most supported model. We found that a modified variant of the model posited by Mathews et al. (1998) was most concordant with observed behavior and that brain activity was related to the model-based hidden states. Particularly, while the valences of the stimuli themselves were encoded primarily in the ventral visual cortex, the model-based detection of threatening targets was associated with increased activity in the bilateral anterior insula, while task effort (i.e. adaptation) was associated with reduction in the activity of these areas. These findings suggest that emotional target detection and adaptation are accomplished partly through increases and decreases, respectively, in the perceived immediate relevance of threatening cues and also demonstrate the efficacy of using HMM to apply theoretical models to human behavior.

Implicit emotion regulation in adolescent girls: An exploratory investigation of Hidden Markov Modeling and its neural correlates

PubMed Central

Bush, Keith; Stowe, Zachary N.; James, George A.; Smitherman, Sonet; Kilts, Clint D.; Cisler, Josh

2018-01-01

Numerous data demonstrate that distracting emotional stimuli cause behavioral slowing (i.e. emotional conflict) and that behavior dynamically adapts to such distractors. However, the cognitive and neural mechanisms that mediate these behavioral findings are poorly understood. Several theoretical models have been developed that attempt to explain these phenomena, but these models have not been directly tested on human behavior nor compared. A potential tool to overcome this limitation is Hidden Markov Modeling (HMM), which is a computational approach to modeling indirectly observed systems. Here, we administered an emotional Stroop task to a sample of healthy adolescent girls (N = 24) during fMRI and used HMM to implement theoretical behavioral models. We then compared the model fits and tested for neural representations of the hidden states of the most supported model. We found that a modified variant of the model posited by Mathews et al. (1998) was most concordant with observed behavior and that brain activity was related to the model-based hidden states. Particularly, while the valences of the stimuli themselves were encoded primarily in the ventral visual cortex, the model-based detection of threatening targets was associated with increased activity in the bilateral anterior insula, while task effort (i.e. adaptation) was associated with reduction in the activity of these areas. These findings suggest that emotional target detection and adaptation are accomplished partly through increases and decreases, respectively, in the perceived immediate relevance of threatening cues and also demonstrate the efficacy of using HMM to apply theoretical models to human behavior. PMID:29489856

When the Mannequin Dies, Creation and Exploration of a Theoretical Framework Using a Mixed Methods Approach.

PubMed

Tripathy, Shreepada; Miller, Karen H; Berkenbosch, John W; McKinley, Tara F; Boland, Kimberly A; Brown, Seth A; Calhoun, Aaron W

2016-06-01

Controversy exists in the simulation community as to the emotional and educational ramifications of mannequin death due to learner action or inaction. No theoretical framework to guide future investigations of learner actions currently exists. The purpose of our study was to generate a model of the learner experience of mannequin death using a mixed methods approach. The study consisted of an initial focus group phase composed of 11 learners who had previously experienced mannequin death due to action or inaction on the part of learners as defined by Leighton (Clin Simul Nurs. 2009;5(2):e59-e62). Transcripts were analyzed using grounded theory to generate a list of relevant themes that were further organized into a theoretical framework. With the use of this framework, a survey was generated and distributed to additional learners who had experienced mannequin death due to action or inaction. Results were analyzed using a mixed methods approach. Forty-one clinicians completed the survey. A correlation was found between the emotional experience of mannequin death and degree of presession anxiety (P < 0.001). Debriefing was found to significantly reduce negative emotion and enhance satisfaction. Sixty-nine percent of respondents indicated that mannequin death enhanced learning. These results were used to modify our framework. Using the previous approach, we created a model of the effect of mannequin death on the educational and psychological state of learners. We offer the final model as a guide to future research regarding the learner experience of mannequin death.

Theoretical scheme of thermal-light many-ghost imaging by Nth-order intensity correlation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Yingchuan; College of Mathematics and Physics, University of South China, Hengyang 421001; Kuang Leman

2011-05-15

In this paper, we propose a theoretical scheme of many-ghost imaging in terms of Nth-order correlated thermal light. We obtain the Gaussian thin lens equations in the many-ghost imaging protocol. We show that it is possible to produce N-1 ghost images of an object at different places in a nonlocal fashion by means of a higher order correlated imaging process with an Nth-order correlated thermal source and correlation measurements. We investigate the visibility of the ghost images in the scheme and obtain the upper bounds of the visibility for the Nth-order correlated thermal-light ghost imaging. It is found that themore » visibility of the ghost images can be dramatically enhanced when the order of correlation becomes larger. It is pointed out that the many-ghost imaging phenomenon is an observable physical effect induced by higher order coherence or higher order correlations of optical fields.« less

Choosing Appropriate Theories for Understanding Hospital Reporting of Adverse Drug Events, a Theoretical Domains Framework Approach

PubMed Central

Shalviri, Gloria; Yazdizadeh, Bahareh; Mirbaha, Fariba; Gholami, Kheirollah; Majdzadeh, Reza

2018-01-01

Adverse drug events (ADEs) may cause serious injuries including death. Spontaneous reporting of ADEs plays a great role in detection and prevention of them; however, underreporting always exists. Although several interventions have been utilized to solve this problem, they are mainly based on experience and the rationale for choosing them has no theoretical base. The vast variety of behavioural theories makes it difficult to choose appropriate theory. Theoretical domains framework (TDF) is suggested as a solution. The objective of this study was to select the best theory for evaluating ADE reporting in hospitals based on TDF. We carried out three focus group discussions with hospital pharmacists and nurses, based on TDF questions. The analysis was performed through five steps including coding discussions transcript, extracting beliefs, selecting relevant domains, matching related constructs to the extracted beliefs, and determining the appropriate theories in each domain. The theory with the highest number of matched domains and constructs was selected as the theory of choice. A total of six domains were identified relevant to ADE reporting, including “Knowledge”, “Skills”, “Beliefs about consequences”, “Motivation and goals”, “Environmental context and resources” and “Social influences”. We found theory of planned behavior as the comprehensive theory to study factors influencing ADE reporting in hospitals, since it was relevant theory in five out of six relevant domains and the common theory in 55 out of 75 identified beliefs. In conclusion, we suggest theory of planned behavior for further studies on designing appropriate interventions to increase ADE reporting in hospitals. PMID:29881437

Choosing Appropriate Theories for Understanding Hospital Reporting of Adverse Drug Events, a Theoretical Domains Framework Approach.

PubMed

Shalviri, Gloria; Yazdizadeh, Bahareh; Mirbaha, Fariba; Gholami, Kheirollah; Majdzadeh, Reza

2018-01-01

Adverse drug events (ADEs) may cause serious injuries including death. Spontaneous reporting of ADEs plays a great role in detection and prevention of them; however, underreporting always exists. Although several interventions have been utilized to solve this problem, they are mainly based on experience and the rationale for choosing them has no theoretical base. The vast variety of behavioural theories makes it difficult to choose appropriate theory. Theoretical domains framework (TDF) is suggested as a solution. The objective of this study was to select the best theory for evaluating ADE reporting in hospitals based on TDF. We carried out three focus group discussions with hospital pharmacists and nurses, based on TDF questions. The analysis was performed through five steps including coding discussions transcript, extracting beliefs, selecting relevant domains, matching related constructs to the extracted beliefs, and determining the appropriate theories in each domain. The theory with the highest number of matched domains and constructs was selected as the theory of choice. A total of six domains were identified relevant to ADE reporting, including "Knowledge", "Skills", "Beliefs about consequences", "Motivation and goals", "Environmental context and resources" and "Social influences". We found theory of planned behavior as the comprehensive theory to study factors influencing ADE reporting in hospitals, since it was relevant theory in five out of six relevant domains and the common theory in 55 out of 75 identified beliefs. In conclusion, we suggest theory of planned behavior for further studies on designing appropriate interventions to increase ADE reporting in hospitals.

Potential determinants of health-care professionals' use of survivorship care plans: a qualitative study using the theoretical domains framework.

PubMed

Birken, Sarah A; Presseau, Justin; Ellis, Shellie D; Gerstel, Adrian A; Mayer, Deborah K

2014-11-15

Survivorship care plans are intended to improve coordination of care for the nearly 14 million cancer survivors in the United States. Evidence suggests that survivorship care plans (SCPs) have positive outcomes for survivors, health-care professionals, and cancer programs, and several high-profile organizations now recommend SCP use. Nevertheless, SCP use remains limited among health-care professionals in United States cancer programs. Knowledge of barriers to SCP use is limited in part because extant studies have used anecdotal evidence to identify determinants. This study uses the theoretical domains framework to identify relevant constructs that are potential determinants of SCP use among United States health-care professionals. We conducted semi-structured interviews to assess the relevance of 12 theoretical domains in predicting SCP use among 13 health-care professionals in 7 cancer programs throughout the United States with diverse characteristics. Relevant theoretical domains were identified through thematic coding of interview transcripts, identification of specific beliefs within coded text units, and mapping of specific beliefs onto theoretical constructs. We found the following theoretical domains (based on specific beliefs) to be potential determinants of SCP use: health-care professionals' beliefs about the consequences of SCP use (benefit to survivors, health-care professionals, and the system as a whole); motivation and goals regarding SCP use (advocating SCP use; extent to which using SCPs competed for health-care professionals' time); environmental context and resources (whether SCPs were delivered at a dedicated visit and whether a system, information technology, and funding facilitated SCP use); and social influences (whether using SCPs is an organizational priority, influential people support SCP use, and people who could assist with SCP use buy into using SCPs). Specific beliefs mapped onto the following psychological constructs: outcome expectancies, intrinsic motivation, goal priority, resources, leadership, and team working. Previous studies have explored a limited range of determinants of SCP use. Our findings suggest a more comprehensive list of potential determinants that could be leveraged to promote SCP use. These results are particularly timely as cancer programs face impending SCP use requirements. Future work should develop instruments to measure the potential determinants and assess their relative influence on SCP use.

GeneLab

NASA Technical Reports Server (NTRS)

Berrios, Daniel C.; Thompson, Terri G.

2015-01-01

NASA GeneLab is expected to capture and distribute omics data and experimental and process conditions most relevant to research community in their statistical and theoretical analysis of NASAs omics data.

"Biosphere Reserve"--The Actual Research Subject of the Sustainable Development Process"

ERIC Educational Resources Information Center

Khasaev, Gabibulla R.; Sadovenko, Marina Yu.; Isaev, Roman O.

2016-01-01

The relevance of the analyzed issue is caused by the growing slippage of research funds of sustainable development in its practice. The purpose of the article is the theoretical basis of the biosphere reserve as a scientific research subject that is relevant to rules of the scientific activity. The leading approach to the study of this issue is…

Subjective evaluation and electroacoustic theoretical validation of a new approach to audio upmixing

NASA Astrophysics Data System (ADS)

Usher, John S.

Audio signal processing systems for converting two-channel (stereo) recordings to four or five channels are increasingly relevant. These audio upmixers can be used with conventional stereo sound recordings and reproduced with multichannel home theatre or automotive loudspeaker audio systems to create a more engaging and natural-sounding listening experience. This dissertation discusses existing approaches to audio upmixing for recordings of musical performances and presents specific design criteria for a system to enhance spatial sound quality. A new upmixing system is proposed and evaluated according to these criteria and a theoretical model for its behavior is validated using empirical measurements. The new system removes short-term correlated components from two electronic audio signals using a pair of adaptive filters, updated according to a frequency domain implementation of the normalized-least-means-square algorithm. The major difference of the new system with all extant audio upmixers is that unsupervised time-alignment of the input signals (typically, by up to +/-10 ms) as a function of frequency (typically, using a 1024-band equalizer) is accomplished due to the non-minimum phase adaptive filter. Two new signals are created from the weighted difference of the inputs, and are then radiated with two loudspeakers behind the listener. According to the consensus in the literature on the effect of interaural correlation on auditory image formation, the self-orthogonalizing properties of the algorithm ensure minimal distortion of the frontal source imagery and natural-sounding, enveloping reverberance (ambiance) imagery. Performance evaluation of the new upmix system was accomplished in two ways: Firstly, using empirical electroacoustic measurements which validate a theoretical model of the system; and secondly, with formal listening tests which investigated auditory spatial imagery with a graphical mapping tool and a preference experiment. Both electroacoustic and subjective methods investigated system performance with a variety of test stimuli for solo musical performances reproduced using a loudspeaker in an orchestral concert-hall and recorded using different microphone techniques. The objective and subjective evaluations combined with a comparative study with two commercial systems demonstrate that the proposed system provides a new, computationally practical, high sound quality solution to upmixing.

Development of a theory-based (PEN-3 and Health Belief Model), culturally relevant intervention on cervical cancer prevention among Latina immigrants using intervention mapping.

PubMed

Scarinci, Isabel C; Bandura, Lisa; Hidalgo, Bertha; Cherrington, Andrea

2012-01-01

The development of efficacious theory-based, culturally relevant interventions to promote cervical cancer prevention among underserved populations is crucial to the elimination of cancer disparities. The purpose of this article is to describe the development of a theory-based, culturally relevant intervention focusing on primary (sexual risk reduction) and secondary (Pap smear) prevention of cervical cancer among Latina immigrants using intervention mapping (IM). The PEN-3 and Health Belief Model provided theoretical guidance for the intervention development and implementation. IM provides a logical five-step framework in intervention development: delineating proximal program objectives, selecting theory-based intervention methods and strategies, developing a program plan, planning for adoption in implementation, and creating evaluation plans and instruments. We first conducted an extensive literature review and qualitatively examined the sociocultural factors associated with primary and secondary prevention of cervical cancer. We then proceeded to quantitatively validate the qualitative findings, which led to development matrices linking the theoretical constructs with intervention objectives and strategies as well as evaluation. IM was a helpful tool in the development of a theory-based, culturally relevant intervention addressing primary and secondary prevention among Latina immigrants.

Development of a Theory-Based (PEN-3 and Health Belief Model), Culturally Relevant Intervention on Cervical Cancer Prevention Among Latina Immigrants Using Intervention Mapping

PubMed Central

Scarinci, Isabel C.; Bandura, Lisa; Hidalgo, Bertha; Cherrington, Andrea

2014-01-01

The development of efficacious theory-based, culturally relevant interventions to promote cervical cancer prevention among underserved populations is crucial to the elimination of cancer disparities. The purpose of this article is to describe the development of a theory-based, culturally relevant intervention focusing on primary (sexual risk reduction) and secondary (Pap smear) prevention of cervical cancer among Latina immigrants using intervention mapping (IM). The PEN-3 and Health Belief Model provided theoretical guidance for the intervention development and implementation. IM provides a logical five-step framework in intervention development: delineating proximal program objectives, selecting theory-based intervention methods and strategies, developing a program plan, planning for adoption in implementation, and creating evaluation plans and instruments. We first conducted an extensive literature review and qualitatively examined the socio-cultural factors associated with primary and secondary prevention of cervical cancer. We then proceeded to quantitatively validate the qualitative findings, which led to development matrices linking the theoretical constructs with intervention objectives and strategies as well as evaluation. IM was a helpful tool in the development of a theory-based, culturally relevant intervention addressing primary and secondary prevention among Latina immigrants. PMID:21422254

Fluid-particle characteristics in fully-developed cluster-induced turbulence

NASA Astrophysics Data System (ADS)

Capecelatro, Jesse; Desjardins, Olivier; Fox, Rodney

2014-11-01

In this study, we present a theoretical framework for collisional fluid-particle turbulence. To identify the key mechanisms responsible for energy exchange between the two phases, an Eulerian-Lagrangian strategy is used to simulate fully-developed cluster-inudced turbulence (CIT) under a range of Reynolds numbers, where fluctuations in particle concentration generate and sustain the carrier-phase turbulence. Using a novel filtering approach, a length-scale separation between the correlated particle velocity and uncorrelated granular temperature (GT) is achieved. This separation allows us to extract the instantaneous Eulerian volume fraction, velocity and GT fields from the Lagrangian data. Direct comparisons can thus be made with the relevant terms that appear in the multiphase turbulence model. It is shown that the granular pressure is highly anisotropic, and thus additional transport equations (as opposed to a single equation for GT) are necessary in formulating a predictive multiphase turbulence model. In addition to reporting the relevant contributions to the Reynolds stresses of each phase, two-point statistics, integral length/timescales, averages conditioned on the local volume fraction, and PDFs of the key multiphase statistics are presented and discussed. The research reported in this paper is partially supported by the HPC equipment purchased through U.S. National Science Foundation MRI Grant Number CNS 1229081 and CRI Grant Number 1205413.

Spin-lattice relaxation study of the methyl proton dynamics in solid 9,10-dimethyltriptycene (DMT).

PubMed

Piślewski, N; Tritt-Goc, J; Bielejewski, M; Rachocki, A; Ratajczyk, T; Szymański, S

2009-06-01

Proton spin-lattice relaxation studies are performed for powder samples of 9,10-dimethyltriptycene (DMT) and its isotopomer DMT-d(12) in which all the non-methyl protons in the molecule are replaced by deuterons. The relaxation data are interpreted in terms of the conventional relaxation theory based on the random jump model in which the Pauli correlations between the relevant spin and torsional states are discarded. The Arrhenius activation energies, obtained from the relaxation data, 25.3 and 24.8 kJ mol(-1) for DMT and DMT-d(12), respectively, are very high as for the methyl groups. The validity of the jump model in the present case is considered from the perspective of Haupt theory in which the Pauli principle is explicitly invoked. To this purpose, the dynamic quantities entering the Haupt model are reinterpreted in the spirit of the damped quantum rotation (DQR) approach introduced recently for the purpose of NMR lineshape studies of hindered molecular rotators. Theoretical modelling of the relevant methyl group dynamics, based on the DQR theory, was performed. From these calculations it is inferred that direct assessments of the torsional barrier heights, based on the Arrhenius activation energies extracted from relaxation data, should be treated with caution.

Randic and Schultz molecular topological indices and their correlation with some X-ray absorption parameters

NASA Astrophysics Data System (ADS)

Khatri, Sunil; Kekre, Pravin A.; Mishra, Ashutosh

2016-10-01

The properties of a molecular system are affected by the topology of molecule. Therefore many studies have been made where the various physic-chemical properties are correlated with the topological indices. These studies have shown a very good correlation demonstrating the utility of the graph theoretical approach. It is, therefore, very natural to expect that the various physical properties obtained by the X-ray absorption spectra may also show correlation with the topological indices. Some complexes were used to establish correlation between topological indices and some X-ray absorption parameters like chemical shift. The chemical shift is on the higher energy side of the metal edge in these complexes. The result obtained in these studies shows that the topological indices of organic molecule acting as a legands can be used for estimating edge shift theoretically.

Theory of correlation in a network with synaptic depression

NASA Astrophysics Data System (ADS)

Igarashi, Yasuhiko; Oizumi, Masafumi; Okada, Masato

2012-01-01

Synaptic depression affects not only the mean responses of neurons but also the correlation of response variability in neural populations. Although previous studies have constructed a theory of correlation in a spiking neuron model by using the mean-field theory framework, synaptic depression has not been taken into consideration. We expanded the previous theoretical framework in this study to spiking neuron models with short-term synaptic depression. On the basis of this theory we analytically calculated neural correlations in a ring attractor network with Mexican-hat-type connectivity, which was used as a model of the primary visual cortex. The results revealed that synaptic depression reduces neural correlation, which could be beneficial for sensory coding. Furthermore, our study opens the way for theoretical studies on the effect of interaction change on the linear response function in large stochastic networks.

Medication competency of nurses according to theoretical and drug calculation online exams: A descriptive correlational study.

PubMed

Sneck, Sami; Saarnio, Reetta; Isola, Arja; Boigu, Risto

2016-01-01

Medication administration is an important task of registered nurses. According to previous studies, nurses lack theoretical knowledge and drug calculation skills and knowledge-based mistakes do occur in clinical practice. Finnish health care organizations started to develop a systematic verification processes for medication competence at the end of the last decade. No studies have yet been made of nurses' theoretical knowledge and drug calculation skills according to these online exams. The aim of this study was to describe the medication competence of Finnish nurses according to theoretical and drug calculation exams. A descriptive correlation design was adopted. Participants and settings All nurses who participated in the online exam in three Finnish hospitals between 1.1.2009 and 31.05.2014 were selected to the study (n=2479). Quantitative methods like Pearson's chi-squared tests, analysis of variance (ANOVA) with post hoc Tukey tests and Pearson's correlation coefficient were used to test the existence of relationships between dependent and independent variables. The majority of nurses mastered the theoretical knowledge needed in medication administration, but 5% of the nurses struggled with passing the drug calculation exam. Theoretical knowledge and drug calculation skills were better in acute care units than in the other units and younger nurses achieved better results in both exams than their older colleagues. The differences found in this study were statistically significant, but not high. Nevertheless, even the tiniest deficiency in theoretical knowledge and drug calculation skills should be focused on. It is important to identify the nurses who struggle in the exams and to plan targeted educational interventions for supporting them. The next step is to study if verification of medication competence has an effect on patient safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relevant Links

Atmospheric Science Data Center

2018-06-15

... Theoretical Basis Document (ATBD) ADAM-M ADAM-M Information AirMISR AirMISR Home Page MISR Home Page Feature Article: Fiery Temperament KONVEX Information SAFARI Home Page AirMSPI Get Google Earth ...

Five ways of being "theoretical": applications to provider-patient communication research.

PubMed

Hall, Judith A; Schmid Mast, Marianne

2009-03-01

Analyzes the term "theoretical" as it applies to the area of provider-patient communication research, in order to understand better at a conceptual level what the term may mean for authors and critics. Based on literature on provider-patient communication. Offers, and discusses, five definitions of the term "theoretical" as it applies to empirical research and its exposition: (1) grounding, (2) referencing, (3) design and analysis, (4) interpretation, and (5) impact. Each of these definitions embodies a different standard for evaluating the theoretical aspects of research. Although it is often said that research on provider-patient communication is not "theoretical" enough, the term is ambiguous and often applied vaguely. A multidimensional analysis reveals that there are several distinct ways in which empirical research can be strong or weak theoretically. Researchers, educators, editors, and reviewers could use the "Five Ways" framework to appraise the theory-relevant strengths and weaknesses of empirical research and its exposition.

Dressing control of biphoton waveform transitions

NASA Astrophysics Data System (ADS)

Li, Xinghua; Zhang, Dan; Zhang, Da; Hao, Ling; Chen, Haixia; Wang, Zhiguo; Zhang, Yanpeng

2018-05-01

We experimentally realize and theoretically analyze narrow-band biphotons generated in a hot rubidium vapor cell by four-wave-mixing processing. A dressing laser beam is used to alternate both linear and nonlinear susceptibilities of the vapor, thereby modifying the biphoton's temporal correlation function. Most notably, the correlation time is increased from 6 to 165 ns. The biphoton shape is also shown to change as a result of the coupled-states dressing. We observed Rabi oscillations and optical precursors in hot atomic vapor cells. We also theoretically simulated biphoton correlation times as influenced by dressing-laser detuning and power, the results of which are consistent with our experiments.

Theoretical dissociation energies for ionic molecules

NASA Technical Reports Server (NTRS)

Langhoff, S. R.; Bauschlicher, C. W., Jr.; Partridge, H.

1986-01-01

Ab initio calculations at the self-consistent-field and singles plus doubles configuration-interaction level are used to determine accurate spectroscopic parameters for most of the alkali and alkaline-earth fluorides, chlorides, oxides, sulfides, hydroxides, and isocyanides. Numerical Hartree-Fock (NHF) calculations are performed on selected systems to ensure that the extended Slater basis sets employed for the diatomic systems are near the Hartree-Fock limit. Extended Gaussian basis sets of at least triple-zeta plus double polarization equality are employed for the triatomic system. With this model, correlation effects are relatively small, but invariably increase the theoretical dissociation energies. The importance of correlating the electrons on both the anion and the metal is discussed. The theoretical dissociation energies are critically compared with the literature to rule out disparate experimental values. Theoretical (sup 2)Pi - (sup 2)Sigma (sup +) energy separations are presented for the alkali oxides and sulfides.

How do small groups make decisions? : A theoretical framework to inform the implementation and study of clinical competency committees.

PubMed

Chahine, Saad; Cristancho, Sayra; Padgett, Jessica; Lingard, Lorelei

2017-06-01

In the competency-based medical education (CBME) approach, clinical competency committees are responsible for making decisions about trainees' competence. However, we currently lack a theoretical model for group decision-making to inform this emerging assessment phenomenon. This paper proposes an organizing framework to study and guide the decision-making processes of clinical competency committees.This is an explanatory, non-exhaustive review, tailored to identify relevant theoretical and evidence-based papers related to small group decision-making. The search was conducted using Google Scholar, Web of Science, MEDLINE, ERIC, and PsycINFO for relevant literature. Using a thematic analysis, two researchers (SC & JP) met four times between April-June 2016 to consolidate the literature included in this review.Three theoretical orientations towards group decision-making emerged from the review: schema, constructivist, and social influence. Schema orientations focus on how groups use algorithms for decision-making. Constructivist orientations focus on how groups construct their shared understanding. Social influence orientations focus on how individual members influence the group's perspective on a decision. Moderators of decision-making relevant to all orientations include: guidelines, stressors, authority, and leadership.Clinical competency committees are the mechanisms by which groups of clinicians will be in charge of interpreting multiple assessment data points and coming to a shared decision about trainee competence. The way in which these committees make decisions can have huge implications for trainee progression and, ultimately, patient care. Therefore, there is a pressing need to build the science of how such group decision-making works in practice. This synthesis suggests a preliminary organizing framework that can be used in the implementation and study of clinical competency committees.

Behavioral inhibition and activation systems in traumatic brain injury.

PubMed

Wong, Christina G; Rapport, Lisa J; Meachen, Sarah-Jane; Hanks, Robin A; Lumley, Mark A

2016-11-01

Personality has been linked to cognitive appraisal and health outcomes; however, research specific to traumatic brain injury (TBI) has been sparse. Gray's theory of behavioral inhibition system and behavioral activation system (BIS/BAS) offers a neurobiologic view of personality that may be especially relevant to neurobehavioral change associated with TBI. The present study examined theoretical and psychometric issues of using the BIS/BAS scale among adults with TBI as well as BIS/BAS personality correlates of TBI. Research Method/Design: Eighty-one adults with complicated-mild to severe TBI and 76 of their significant others (SOs) participated. Measures included the BIS/BAS scale, Positive and Negative Affect Schedule, and Awareness Questionnaire. Among adults with TBI, BIS/BAS internal consistency reliabilities were similar to those found in normative samples of adults without TBI. The TBI group endorsed significantly higher BAS than did the SO group, and injury severity was positively correlated to BAS. The SO group showed expected patterns of correlation between personality and affect; positive affect was associated with BAS, and negative affect with BIS. In contrast, in the TBI group, BAS was positively correlated to both positive and negative affect. Impaired awareness of abilities moderated the intensity of relationships between BIS/BAS and affect. TBI was associated with relatively intensified BAS (approach behavior) but not BIS (avoidance behavior). The observed pattern is consistent with the neurobiology of TBI-related personality change and with theory regarding the independence of the BIS and BAS systems. The BIS/BAS scale shows promise as a personality measure in TBI. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Temporal evolution of the Green's function reconstruction in the seismic coda

NASA Astrophysics Data System (ADS)

Clerc, V.; Roux, P.; Campillo, M.

2013-12-01

In presence of multiple scattering, the wavefield evolves towards an equipartitioned state, equivalent to ambient noise. CAMPILLO and PAUL (2003) reconstructed the surface wave part of the Green's function between three pairs of stations in Mexico. The data indicate that the time asymmetry between causal and acausal part of the Green's function is less pronounced when the correlation is performed in the later windows of the coda. These results on the correlation of diffuse waves provide another perspective on the reconstruction of Green function which is independent of the source distribution and which suggests that if the time of observation is long enough, a single source could be sufficient. The paper by ROUX et al. (2005) provides a theoretical frame for the reconstruction of the Green's function in a homogeneous middle. In a multiple scattering medium with a single source, scatterers behave as secondary sources according to the Huygens principle. Coda waves are relevant to multiple scattering, a regime which can be approximated by diffusion for long lapse times. We express the temporal evolution of the correlation function between two receivers as a function of the secondary sources. We are able to predict the effect of the persistence of the net flux of energy observed by CAMPILLO and PAUL (2003) in numerical simulations. This method is also effective in order to retrieve the scattering mean free path. We perform a partial reconstruction of the Green's function in a strongly scattering medium in numerical simulations. The prediction of the flux asymmetry allows defining the parts of the coda providing the same information as ambient noise cross correlation.

Evaluating the Theoretic Adequacy and Applied Potential of Computational Models of the Spacing Effect.

PubMed

Walsh, Matthew M; Gluck, Kevin A; Gunzelmann, Glenn; Jastrzembski, Tiffany; Krusmark, Michael

2018-06-01

The spacing effect is among the most widely replicated empirical phenomena in the learning sciences, and its relevance to education and training is readily apparent. Yet successful applications of spacing effect research to education and training is rare. Computational modeling can provide the crucial link between a century of accumulated experimental data on the spacing effect and the emerging interest in using that research to enable adaptive instruction. In this paper, we review relevant literature and identify 10 criteria for rigorously evaluating computational models of the spacing effect. Five relate to evaluating the theoretic adequacy of a model, and five relate to evaluating its application potential. We use these criteria to evaluate a novel computational model of the spacing effect called the Predictive Performance Equation (PPE). Predictive Performance Equation combines elements of earlier models of learning and memory including the General Performance Equation, Adaptive Control of Thought-Rational, and the New Theory of Disuse, giving rise to a novel computational account of the spacing effect that performs favorably across the complete sets of theoretic and applied criteria. We implemented two other previously published computational models of the spacing effect and compare them to PPE using the theoretic and applied criteria as guides. Copyright © 2018 Cognitive Science Society, Inc.

Flow through a very porous obstacle in a shallow channel

PubMed Central

Draper, S.; Nishino, T.; Borthwick, A. G. L.

2017-01-01

A theoretical model, informed by numerical simulations based on the shallow water equations, is developed to predict the flow passing through and around a uniform porous obstacle in a shallow channel, where background friction is important. This problem is relevant to a number of practical situations, including flow through aquatic vegetation, the performance of arrays of turbines in tidal channels and hydrodynamic forces on offshore structures. To demonstrate this relevance, the theoretical model is used to (i) reinterpret core flow velocities in existing laboratory-based data for an array of emergent cylinders in shallow water emulating aquatic vegetation and (ii) reassess the optimum arrangement of tidal turbines to generate power in a tidal channel. Comparison with laboratory-based data indicates a maximum obstacle resistance (or minimum porosity) for which the present theoretical model is valid. When the obstacle resistance is above this threshold the shallow water equations do not provide an adequate representation of the flow, and the theoretical model over-predicts the core flow passing through the obstacle. The second application of the model confirms that natural bed resistance increases the power extraction potential for a partial tidal fence in a shallow channel and alters the optimum arrangement of turbines within the fence. PMID:28484321

A queer-theoretical approach to community health psychology.

PubMed

Easpaig, Bróna R Nic Giolla; Fryer, David M; Linn, Seònaid E; Humphrey, Rhianna H

2014-01-01

Queer-theoretical resources offer ways of productively rethinking how central concepts such as 'person-context', 'identity' and 'difference' may be understood for community health psychologists. This would require going beyond consideration of the problems with which queer theory is popularly associated to cautiously engage with the aspects of this work relevant to the promotion of collective practice and engaging with processes of marginalisation. In this article, we will draw upon and illustrate the queer-theoretical concepts of 'performativity' and 'cultural intelligibility' before moving towards a preliminary mapping of what a queer-informed approach to community health psychology might involve.

Les Houches 2017: Physics at TeV Colliders Standard Model Working Group Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersen, J.R.; et al.

This Report summarizes the proceedings of the 2017 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments relevant for high precision Standard Model calculations, (II) theoretical uncertainties and dataset dependence of parton distribution functions, (III) new developments in jet substructure techniques, (IV) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, (V) phenomenological studies essential for comparing LHC data from Run II with theoretical predictions and projections for future measurements, and (VI) new developments in Monte Carlo event generators.

The Relevance of Foucauldian Art-of-Living for Ethics Education in a Military Context: Theory and Practice

ERIC Educational Resources Information Center

van Baarle, Eva; Verweij, Desiree; Molewijk, Bert; Widdershoven, Guy

2018-01-01

How can ethical decision-making in organizations be further reinforced? This article explores the relevance of Michel Foucault's ideas on art-of-living for ethics education in organizations. First, we present a theoretical analysis of art-of-living in the work of Foucault as well as in the work of two philosophers who greatly influenced his work,…

AIRBORNE INVESTIGATIONS OF CLEAR AIR TURBULENCE WITH OPTICAL RADAR.

DTIC Science & Technology

relevant meteorlogical data. The design of this equipment and the development of the flight programs was predicated on theoretical considerations of optical scattering from particulate matter. (Author)

Signatures of criticality arise from random subsampling in simple population models.

PubMed

Nonnenmacher, Marcel; Behrens, Christian; Berens, Philipp; Bethge, Matthias; Macke, Jakob H

2017-10-01

The rise of large-scale recordings of neuronal activity has fueled the hope to gain new insights into the collective activity of neural ensembles. How can one link the statistics of neural population activity to underlying principles and theories? One attempt to interpret such data builds upon analogies to the behaviour of collective systems in statistical physics. Divergence of the specific heat-a measure of population statistics derived from thermodynamics-has been used to suggest that neural populations are optimized to operate at a "critical point". However, these findings have been challenged by theoretical studies which have shown that common inputs can lead to diverging specific heat. Here, we connect "signatures of criticality", and in particular the divergence of specific heat, back to statistics of neural population activity commonly studied in neural coding: firing rates and pairwise correlations. We show that the specific heat diverges whenever the average correlation strength does not depend on population size. This is necessarily true when data with correlations is randomly subsampled during the analysis process, irrespective of the detailed structure or origin of correlations. We also show how the characteristic shape of specific heat capacity curves depends on firing rates and correlations, using both analytically tractable models and numerical simulations of a canonical feed-forward population model. To analyze these simulations, we develop efficient methods for characterizing large-scale neural population activity with maximum entropy models. We find that, consistent with experimental findings, increases in firing rates and correlation directly lead to more pronounced signatures. Thus, previous reports of thermodynamical criticality in neural populations based on the analysis of specific heat can be explained by average firing rates and correlations, and are not indicative of an optimized coding strategy. We conclude that a reliable interpretation of statistical tests for theories of neural coding is possible only in reference to relevant ground-truth models.

Time-correlated gust loads using matched filter theory and random process theory - A new way of looking at things

NASA Technical Reports Server (NTRS)

Pototzky, Anthony S.; Zeiler, Thomas A.; Perry, Boyd, III

1989-01-01

This paper describes and illustrates two ways of performing time-correlated gust-load calculations. The first is based on Matched Filter Theory; the second on Random Process Theory. Both approaches yield theoretically identical results and represent novel applications of the theories, are computationally fast, and may be applied to other dynamic-response problems. A theoretical development and example calculations using both Matched Filter Theory and Random Process Theory approaches are presented.

Time-correlated gust loads using Matched-Filter Theory and Random-Process Theory: A new way of looking at things

NASA Technical Reports Server (NTRS)

Pototzky, Anthony S.; Zeiler, Thomas A.; Perry, Boyd, III

1989-01-01

Two ways of performing time-correlated gust-load calculations are described and illustrated. The first is based on Matched Filter Theory; the second on Random Process Theory. Both approaches yield theoretically identical results and represent novel applications of the theories, are computationally fast, and may be applied to other dynamic-response problems. A theoretical development and example calculations using both Matched Filter Theory and Random Process Theory approaches are presented.

Comparison of Theory and Experiment on Aeroacoustic Loads and Deflections

NASA Astrophysics Data System (ADS)

Campos, L. M. B. C.; Bourgine, A.; Bonomi, B.

1999-01-01

The correlation of acoustic pressure loads induced by a turbulent wake on a nearby structural panel is considered: this problem is relevant to the acoustic fatigue of aircraft, rocket and satellite structures. Both the correlation of acoustic pressure loads and the panel deflections, were measured in an 8-m diameter transonic wind tunnel. Using the measured correlation of acoustic pressures, as an input to a finite-element aeroelastic code, the panel response was reproduced. The latter was also satisfactorily reproduced, using again the aeroelastic code, with input given by a theoretical formula for the correlation of acoustic pressures; the derivation of this formula, and the semi-empirical parameters which appear in it, are included in this paper. The comparison of acoustic responses in aeroacoustic wind tunnels (AWT) and progressive wave tubes (PWT) shows that much work needs to be done to bridge that gap; this is important since the PWT is the standard test means, whereas the AWT is more representative of real flight conditions but also more demanding in resources. Since this may be the first instance of successful modelling of acoustic fatigue, it may be appropriate to list briefly the essential ``positive'' features and associated physical phenomena: (i) a standard aeroelastic structural code can predict acoustic fatigue, provided that the correlation of pressure loads be adequately specified; (ii) the correlation of pressure loads is determined by the interference of acoustic waves, which depends on the exact evaluation of multiple scattering integrals, involving the statistics of random phase shifts; (iii) for the relatively low frequencies (one to a few hundred Hz) of aeroacoustic fatigue, the main cause of random phase effects is scattering by irregular wakes, which are thin on wavelength scale, and appear as partially reflecting rough interfaces. It may also be appropriate to mention some of the ``negative'' features, to which may be attached illusory importance; (iv) deterministic flow features, even conspicuous or of large scale, such as convection, are not relevant to aeroacoustic fatigue, because they do not produce random phase shifts; (v) local turbulence, of scale much smaller than the wavelength of sound, cannot produce significant random phase shifts, and is also of little consequence to aeroacoustic fatigue; (vi) the precise location of sound sources can become of little consequence, after multiple scattering gives rise to a diffuse sound field; and (vii) there is not much ground for distinction between unsteady flow and sound waves, since at transonic speeds they are both associated with pressures fluctuating in time and space.

Correlations among experimental and theoretical NMR data to determine the absolute stereochemistry of darcyribeirine, a pentacyclic indole alkaloid isolated from Rauvolfia grandiflora

NASA Astrophysics Data System (ADS)

Cancelieri, Náuvia Maria; Ferreira, Thiago Resende; Vieira, Ivo José Curcino; Braz-Filho, Raimundo; Piló-Veloso, Dorila; Alcântara, Antônio Flávio de Carvalho

2015-10-01

Darcyribeirine (1) is a pentacyclic indole alkaloid isolated from Rauvolfia grandiflora. Stereochemistry of 1 was previously proposed based on 1D (coupling constant data) and 2D (NOESY correlations) NMR techniques, having been established a configuration 3R, 15S, and 20R (isomer 1a). Stereoisomers of 1 (i.e., 1a-1h) can be grouped into four sets of enantiomers. Carbon chemical shifts and hydrogen coupling constants were calculated using BLYP/6-31G* theory level for the eight isomers of 1. Calculated NMR data of 1a-1h were correlated with the corresponding experimental data of 1. The best correlations between theoretical and experimental carbon chemical shift data were obtained for the set of enantiomers 1e/1f to structures in the gaseous phase and considering solvent effects (using PCM and explicit models). Similar results were obtained when the same procedure was performed to correlations between theoretical and experimental coupling constant data. Finally, optical rotation calculations indicate 1e as its absolute stereochemistry. Orbital population analysis indicates that the hydrogen bonding between N-H of 1e and DMSO is due to contributions of its frontier unoccupied molecular orbitals, mainly LUMO+1, LUMO+2, and LUMO+3.

The Teamwork Assessment Scale: A Novel Instrument to Assess Quality of Undergraduate Medical Students' Teamwork Using the Example of Simulation-based Ward-Rounds.

PubMed

Kiesewetter, Jan; Fischer, Martin R

2015-01-01

Simulation-based teamwork trainings are considered a powerful training method to advance teamwork, which becomes more relevant in medical education. The measurement of teamwork is of high importance and several instruments have been developed for various medical domains to meet this need. To our knowledge, no theoretically-based and easy-to-use measurement instrument has been published nor developed specifically for simulation-based teamwork trainings of medical students. Internist ward-rounds function as an important example of teamwork in medicine. The purpose of this study was to provide a validated, theoretically-based instrument that is easy-to-use. Furthermore, this study aimed to identify if and when rater scores relate to performance. Based on a theoretical framework for teamwork behaviour, items regarding four teamwork components (Team Coordination, Team Cooperation, Information Exchange, Team Adjustment Behaviours) were developed. In study one, three ward-round scenarios, simulated by 69 students, were videotaped and rated independently by four trained raters. The instrument was tested for the embedded psychometric properties and factorial structure. In study two, the instrument was tested for construct validity with an external criterion with a second set of 100 students and four raters. In study one, the factorial structure matched the theoretical components but was unable to separate Information Exchange and Team Cooperation. The preliminary version showed adequate psychometric properties (Cronbach's α=.75). In study two, the instrument showed physician rater scores were more reliable in measurement than those of student raters. Furthermore, a close correlation between the scale and clinical performance as an external criteria was shown (r=.64) and the sufficient psychometric properties were replicated (Cronbach's α=.78). The validation allows for use of the simulated teamwork assessment scale in undergraduate medical ward-round trainings to reliably measure teamwork by physicians. Further studies are needed to verify the applicability of the instrument.

The Teamwork Assessment Scale: A Novel Instrument to Assess Quality of Undergraduate Medical Students' Teamwork Using the Example of Simulation-based Ward-Rounds

PubMed Central

Kiesewetter, Jan; Fischer, Martin R.

2015-01-01

Background: Simulation-based teamwork trainings are considered a powerful training method to advance teamwork, which becomes more relevant in medical education. The measurement of teamwork is of high importance and several instruments have been developed for various medical domains to meet this need. To our knowledge, no theoretically-based and easy-to-use measurement instrument has been published nor developed specifically for simulation-based teamwork trainings of medical students. Internist ward-rounds function as an important example of teamwork in medicine. Purposes: The purpose of this study was to provide a validated, theoretically-based instrument that is easy-to-use. Furthermore, this study aimed to identify if and when rater scores relate to performance. Methods: Based on a theoretical framework for teamwork behaviour, items regarding four teamwork components (Team Coordination, Team Cooperation, Information Exchange, Team Adjustment Behaviours) were developed. In study one, three ward-round scenarios, simulated by 69 students, were videotaped and rated independently by four trained raters. The instrument was tested for the embedded psychometric properties and factorial structure. In study two, the instrument was tested for construct validity with an external criterion with a second set of 100 students and four raters. Results: In study one, the factorial structure matched the theoretical components but was unable to separate Information Exchange and Team Cooperation. The preliminary version showed adequate psychometric properties (Cronbach’s α=.75). In study two, the instrument showed physician rater scores were more reliable in measurement than those of student raters. Furthermore, a close correlation between the scale and clinical performance as an external criteria was shown (r=.64) and the sufficient psychometric properties were replicated (Cronbach’s α=.78). Conclusions: The validation allows for use of the simulated teamwork assessment scale in undergraduate medical ward-round trainings to reliably measure teamwork by physicians. Further studies are needed to verify the applicability of the instrument. PMID:26038684

Development and Validation of the Scan of Postgraduate Educational Environment Domains (SPEED): A Brief Instrument to Assess the Educational Environment in Postgraduate Medical Education

PubMed Central

Schönrock-Adema, Johanna; Visscher, Maartje; Raat, A. N. Janet; Brand, Paul L. P.

2015-01-01

Introduction Current instruments to evaluate the postgraduate medical educational environment lack theoretical frameworks and are relatively long, which may reduce response rates. We aimed to develop and validate a brief instrument that, based on a solid theoretical framework for educational environments, solicits resident feedback to screen the postgraduate medical educational environment quality. Methods Stepwise, we developed a screening instrument, using existing instruments to assess educational environment quality and adopting a theoretical framework that defines three educational environment domains: content, atmosphere and organization. First, items from relevant existing instruments were collected and, after deleting duplicates and items not specifically addressing educational environment, grouped into the three domains. In a Delphi procedure, the item list was reduced to a set of items considered most important and comprehensively covering the three domains. These items were triangulated against the results of semi-structured interviews with 26 residents from three teaching hospitals to achieve face validity. This draft version of the Scan of Postgraduate Educational Environment Domains (SPEED) was administered to residents in a general and university hospital and further reduced and validated based on the data collected. Results Two hundred twenty-three residents completed the 43-item draft SPEED. We used half of the dataset for item reduction, and the other half for validating the resulting SPEED (15 items, 5 per domain). Internal consistencies were high. Correlations between domain scores in the draft and brief versions of SPEED were high (>0.85) and highly significant (p<0.001). Domain score variance of the draft instrument was explained for ≥80% by the items representing the domains in the final SPEED. Conclusions The SPEED comprehensively covers the three educational environment domains defined in the theoretical framework. Because of its validity and brevity, the SPEED is promising as useful and easily applicable tool to regularly screen educational environment quality in postgraduate medical education. PMID:26413836

Some theoretical models and constructs generic to substance abuse prevention programs for adolescents: possible relevance and limitations for problem gambling.

PubMed

Evans, Richard I

2003-01-01

For the past several years the author and his colleagues have explored the area of how social psychological constructs and theoretical models can be applied to the prevention of health threatening behaviors in adolescents. In examining the need for the development of gambling prevention programs for adolescents, it might be of value to consider the application of such constructs and theoretical models as a foundation to the development of prevention programs in this emerging problem behavior among adolescents. In order to provide perspective to the reader, the present paper reviews the history of various psychosocial models and constructs generic to programs directed at prevention of substance abuse in adolescents. A brief history of some of these models, possibly most applicable to gambling prevention programs, are presented. Social inoculation, reasoned action, planned behavior, and problem behavior theory, are among those discussed. Some deficits of these models, are also articulated. How such models may have relevance to developing programs for prevention of problem gambling in adolescents is also discussed. However, the inherent differences between gambling and more directly health threatening behaviors such as substance abuse must, of course, be seriously considered in utilizing such models. Most current gambling prevention programs have seldom been guided by theoretical models. Developers of gambling prevention programs should consider theoretical foundations, particularly since such foundations not only provide a guide for programs, but may become critical tools in evaluating their effectiveness.

[Does co-operation research provide approaches to explain the changes in the German hospital market?].

PubMed

Raible, C; Leidl, R

2004-11-01

The German hospital market faces an extensive process of consolidation. In this change hospitals consider cooperation as one possibility to improve competitiveness. To investigate explanations of changes in the German hospital market by theoretical approaches of cooperation research. The aims and mechanism of the theories, their relevance in terms of contents and their potential for empirical tests were used as criteria to assess the approaches, with current and future trends in the German hospital market providing the framework. Based on literature review, six theoretical approaches were investigated: industrial organization, transaction cost theory, game theory, resource dependency, institutional theory, and co-operative investment and finance theory. In addition, the data needed to empirically test the theories were specified. As a general problem, some of the theoretical approaches set a perfect market as a precondition. This precondition is not met by the heavily regulated German hospital market. Given the current regulations and the assessment criteria, industrial organization as well as resource-dependency and institutional theory approaches showed the highest potential to explain various aspects of the changes in the hospital market. So far, none of the approaches investigated provides a comprehensive and empirically tested explanation of the changes in the German hospital market. However, some of the approaches provide a theoretical background for part of the changes. As this dynamic market is economically of high significance, there is a need for further development and empirical testing of relevant theoretical approaches.

Reconstructing networks from dynamics with correlated noise

NASA Astrophysics Data System (ADS)

Tam, H. C.; Ching, Emily S. C.; Lai, Pik-Yin

2018-07-01

Reconstructing the structure of complex networks from measurements of the nodes is a challenge in many branches of science. External influences are always present and act as a noise to the networks of interest. In this paper, we present a method for reconstructing networks from measured dynamics of the nodes subjected to correlated noise that cannot be approximated by a white noise. This method can reconstruct the links of both bidirectional and directed networks, the correlation time and strength of the noise, and also the relative coupling strength of the links when the coupling functions have certain properties. Our method is built upon theoretical relations between network structure and measurable quantities from the dynamics that we have derived for systems that have fixed point dynamics in the noise-free limit. Using these theoretical results, we can further explain the shortcomings of two common practices of inferring links for bidirectional networks using the Pearson correlation coefficient and the partial correlation coefficient.

Enhanced correlation of received power-signal fluctuations in bidirectional optical links

NASA Astrophysics Data System (ADS)

Minet, Jean; Vorontsov, Mikhail A.; Polnau, Ernst; Dolfi, Daniel

2013-02-01

A study of the correlation between the power signals received at both ends of bidirectional free-space optical links is presented. By use of the quasi-optical approximation, we show that an ideal (theoretically 100%) power-signal correlation can be achieved in optical links with specially designed monostatic transceivers based on single-mode fiber collimators. The theoretical prediction of enhanced correlation is supported both by experiments conducted over a 7 km atmospheric path and wave optics numerical analysis of the corresponding bidirectional optical link. In the numerical simulations, we also compare correlation properties of received power signals for different atmospheric conditions and for optical links with monostatic and bistatic geometries based on single-mode fiber collimator and on power-in-the-bucket transceiver types. Applications of the observed phenomena for signal fading mitigation and turbulence-enhanced communication link security in free-space laser communication links are discussed.

Joint Concept Correlation and Feature-Concept Relevance Learning for Multilabel Classification.

PubMed

Zhao, Xiaowei; Ma, Zhigang; Li, Zhi; Li, Zhihui

2018-02-01

In recent years, multilabel classification has attracted significant attention in multimedia annotation. However, most of the multilabel classification methods focus only on the inherent correlations existing among multiple labels and concepts and ignore the relevance between features and the target concepts. To obtain more robust multilabel classification results, we propose a new multilabel classification method aiming to capture the correlations among multiple concepts by leveraging hypergraph that is proved to be beneficial for relational learning. Moreover, we consider mining feature-concept relevance, which is often overlooked by many multilabel learning algorithms. To better show the feature-concept relevance, we impose a sparsity constraint on the proposed method. We compare the proposed method with several other multilabel classification methods and evaluate the classification performance by mean average precision on several data sets. The experimental results show that the proposed method outperforms the state-of-the-art methods.

Multi-scale Modeling of Chromosomal DNA in Living Cells

NASA Astrophysics Data System (ADS)

Spakowitz, Andrew

The organization and dynamics of chromosomal DNA play a pivotal role in a range of biological processes, including gene regulation, homologous recombination, replication, and segregation. Establishing a quantitative theoretical model of DNA organization and dynamics would be valuable in bridging the gap between the molecular-level packaging of DNA and genome-scale chromosomal processes. Our research group utilizes analytical theory and computational modeling to establish a predictive theoretical model of chromosomal organization and dynamics. In this talk, I will discuss our efforts to develop multi-scale polymer models of chromosomal DNA that are both sufficiently detailed to address specific protein-DNA interactions while capturing experimentally relevant time and length scales. I will demonstrate how these modeling efforts are capable of quantitatively capturing aspects of behavior of chromosomal DNA in both prokaryotic and eukaryotic cells. This talk will illustrate that capturing dynamical behavior of chromosomal DNA at various length scales necessitates a range of theoretical treatments that accommodate the critical physical contributions that are relevant to in vivo behavior at these disparate length and time scales. National Science Foundation, Physics of Living Systems Program (PHY-1305516).

The Correlation between Rigor and Relevance Using Pedagogical or Andragogical Instructional Methods in American Business Schools

ERIC Educational Resources Information Center

Roldan, Alberto

2010-01-01

The purpose of this study was to examine and document whether there is a correlation between relevance (applicability) focused courses and rigor (scholarly research) focused courses with pedagogical instructional methods or andragogical instructional methods in undergraduate business schools, and how it affects learning behavior and final course…

Theoretical framework to study exercise motivation for breast cancer risk reduction.

PubMed

Wood, Maureen E

2008-01-01

To identify an appropriate theoretical framework to study exercise motivation for breast cancer risk reduction among high-risk women. An extensive review of the literature was conducted to gather relevant information pertaining to the Health Promotion Model, self-determination theory, social cognitive theory, Health Belief Model, Transtheoretical Model, theory of planned behavior, and protection motivation theory. An iterative approach was used to summarize the literature related to exercise motivation within each theoretical framework. Protection motivation theory could be used to examine the effects of perceived risk and self-efficacy in motivating women to exercise to facilitate health-related behavioral change. Evidence-based research within a chosen theoretical model can aid practitioners when making practical recommendations to reduce breast cancer risk.

Refraction error correction for deformation measurement by digital image correlation at elevated temperature

NASA Astrophysics Data System (ADS)

Su, Yunquan; Yao, Xuefeng; Wang, Shen; Ma, Yinji

2017-03-01

An effective correction model is proposed to eliminate the refraction error effect caused by an optical window of a furnace in digital image correlation (DIC) deformation measurement under high-temperature environment. First, a theoretical correction model with the corresponding error correction factor is established to eliminate the refraction error induced by double-deck optical glass in DIC deformation measurement. Second, a high-temperature DIC experiment using a chromium-nickel austenite stainless steel specimen is performed to verify the effectiveness of the correction model by the correlation calculation results under two different conditions (with and without the optical glass). Finally, both the full-field and the divisional displacement results with refraction influence are corrected by the theoretical model and then compared to the displacement results extracted from the images without refraction influence. The experimental results demonstrate that the proposed theoretical correction model can effectively improve the measurement accuracy of DIC method by decreasing the refraction errors from measured full-field displacements under high-temperature environment.

Statistical power as a function of Cronbach alpha of instrument questionnaire items.

PubMed

Heo, Moonseong; Kim, Namhee; Faith, Myles S

2015-10-14

In countless number of clinical trials, measurements of outcomes rely on instrument questionnaire items which however often suffer measurement error problems which in turn affect statistical power of study designs. The Cronbach alpha or coefficient alpha, here denoted by C(α), can be used as a measure of internal consistency of parallel instrument items that are developed to measure a target unidimensional outcome construct. Scale score for the target construct is often represented by the sum of the item scores. However, power functions based on C(α) have been lacking for various study designs. We formulate a statistical model for parallel items to derive power functions as a function of C(α) under several study designs. To this end, we assume fixed true score variance assumption as opposed to usual fixed total variance assumption. That assumption is critical and practically relevant to show that smaller measurement errors are inversely associated with higher inter-item correlations, and thus that greater C(α) is associated with greater statistical power. We compare the derived theoretical statistical power with empirical power obtained through Monte Carlo simulations for the following comparisons: one-sample comparison of pre- and post-treatment mean differences, two-sample comparison of pre-post mean differences between groups, and two-sample comparison of mean differences between groups. It is shown that C(α) is the same as a test-retest correlation of the scale scores of parallel items, which enables testing significance of C(α). Closed-form power functions and samples size determination formulas are derived in terms of C(α), for all of the aforementioned comparisons. Power functions are shown to be an increasing function of C(α), regardless of comparison of interest. The derived power functions are well validated by simulation studies that show that the magnitudes of theoretical power are virtually identical to those of the empirical power. Regardless of research designs or settings, in order to increase statistical power, development and use of instruments with greater C(α), or equivalently with greater inter-item correlations, is crucial for trials that intend to use questionnaire items for measuring research outcomes. Further development of the power functions for binary or ordinal item scores and under more general item correlation strutures reflecting more real world situations would be a valuable future study.

Monte Carlo study of four dimensional binary hard hypersphere mixtures

NASA Astrophysics Data System (ADS)

Bishop, Marvin; Whitlock, Paula A.

2012-01-01

A multithreaded Monte Carlo code was used to study the properties of binary mixtures of hard hyperspheres in four dimensions. The ratios of the diameters of the hyperspheres examined were 0.4, 0.5, 0.6, and 0.8. Many total densities of the binary mixtures were investigated. The pair correlation functions and the equations of state were determined and compared with other simulation results and theoretical predictions. At lower diameter ratios the pair correlation functions of the mixture agree with the pair correlation function of a one component fluid at an appropriately scaled density. The theoretical results for the equation of state compare well to the Monte Carlo calculations for all but the highest densities studied.

Theoretical Foundation for Weld Modeling

NASA Technical Reports Server (NTRS)

Traugott, S.

1986-01-01

Differential equations describe physics of tungsten/inert-gas and plasma-arc welding in aluminum. Report collects and describes necessary theoretical foundation upon which numerical welding model is constructed for tungsten/inert gas or plasma-arc welding in aluminum without keyhole. Governing partial differential equations for flow of heat, metal, and current given, together with boundary conditions relevant to welding process. Numerical estimates for relative importance of various phenomena and required properties of 2219 aluminum included

Recent Excitation, Charge Exchange, and Lifetime Results in Highly Charged Ions Relevant to Stellar, Interstellar, Solar and Comet Phenomena

NASA Technical Reports Server (NTRS)

Chutjian, A.; Hossain, S.; Mawhorter, R. J.; Smith, S. J.

2006-01-01

Recent JPL absolute excitation and charge exchange cross sections, and measurements of lifetimes of metastable levels in highly-charged ions (HCIs) are reported. These data provide benchmark comparisons to results of theoretical calculations. Theoretical approaches can then be used to calculate the vast array of data which cannot be measured due to experimental constraints. Applications to the X-ray emission from comets are given.

Images of Inherited War: Three American Presidents in Vietnam

DTIC Science & Technology

2011-06-01

Dependent Realism to demonstrate how theoretical advances in modern physical science correlate to cognitive theories in International Relations. We...Quantum Physics and Model-Dependent Realism In his book, The Grand Design, theoretical physicist and cosmologist Stephen Hawking draws on theoretical...exhibited wave-like properties and that existing scientific laws could not account for their behavior. Newtonian physics was “built on a framework

Computational models of music perception and cognition II: Domain-specific music processing

NASA Astrophysics Data System (ADS)

Purwins, Hendrik; Grachten, Maarten; Herrera, Perfecto; Hazan, Amaury; Marxer, Ricard; Serra, Xavier

2008-09-01

In Part I [Purwins H, Herrera P, Grachten M, Hazan A, Marxer R, Serra X. Computational models of music perception and cognition I: The perceptual and cognitive processing chain. Physics of Life Reviews 2008, in press, doi:10.1016/j.plrev.2008.03.004], we addressed the study of cognitive processes that underlie auditory perception of music, and their neural correlates. The aim of the present paper is to summarize empirical findings from music cognition research that are relevant to three prominent music theoretic domains: rhythm, melody, and tonality. Attention is paid to how cognitive processes like category formation, stimulus grouping, and expectation can account for the music theoretic key concepts in these domains, such as beat, meter, voice, consonance. We give an overview of computational models that have been proposed in the literature for a variety of music processing tasks related to rhythm, melody, and tonality. Although the present state-of-the-art in computational modeling of music cognition definitely provides valuable resources for testing specific hypotheses and theories, we observe the need for models that integrate the various aspects of music perception and cognition into a single framework. Such models should be able to account for aspects that until now have only rarely been addressed in computational models of music cognition, like the active nature of perception and the development of cognitive capacities from infancy to adulthood.

Theoretical models for supercritical fluid extraction.

PubMed

Huang, Zhen; Shi, Xiao-Han; Jiang, Wei-Juan

2012-08-10

For the proper design of supercritical fluid extraction processes, it is essential to have a sound knowledge of the mass transfer mechanism of the extraction process and the appropriate mathematical representation. In this paper, the advances and applications of kinetic models for describing supercritical fluid extraction from various solid matrices have been presented. The theoretical models overviewed here include the hot ball diffusion, broken and intact cell, shrinking core and some relatively simple models. Mathematical representations of these models have been in detail interpreted as well as their assumptions, parameter identifications and application examples. Extraction process of the analyte solute from the solid matrix by means of supercritical fluid includes the dissolution of the analyte from the solid, the analyte diffusion in the matrix and its transport to the bulk supercritical fluid. Mechanisms involved in a mass transfer model are discussed in terms of external mass transfer resistance, internal mass transfer resistance, solute-solid interactions and axial dispersion. The correlations of the external mass transfer coefficient and axial dispersion coefficient with certain dimensionless numbers are also discussed. Among these models, the broken and intact cell model seems to be the most relevant mathematical model as it is able to provide realistic description of the plant material structure for better understanding the mass-transfer kinetics and thus it has been widely employed for modeling supercritical fluid extraction of natural matters. Copyright © 2012 Elsevier B.V. All rights reserved.

Statistical Power for the Comparative Regression Discontinuity Design With a Pretest No-Treatment Control Function: Theory and Evidence From the National Head Start Impact Study.

PubMed

Tang, Yang; Cook, Thomas D

2018-01-01

The basic regression discontinuity design (RDD) has less statistical power than a randomized control trial (RCT) with the same sample size. Adding a no-treatment comparison function to the basic RDD creates a comparative RDD (CRD); and when this function comes from the pretest value of the study outcome, a CRD-Pre design results. We use a within-study comparison (WSC) to examine the power of CRD-Pre relative to both basic RDD and RCT. We first build the theoretical foundation for power in CRD-Pre, then derive the relevant variance formulae, and finally compare them to the theoretical RCT variance. We conclude from this theoretical part of this article that (1) CRD-Pre's power gain depends on the partial correlation between the pretest and posttest measures after conditioning on the assignment variable, (2) CRD-Pre is less responsive than basic RDD to how the assignment variable is distributed and where the cutoff is located, and (3) under a variety of conditions, the efficiency of CRD-Pre is very close to that of the RCT. Data from the National Head Start Impact Study are then used to construct RCT, RDD, and CRD-Pre designs and to compare their power. The empirical results indicate (1) a high level of correspondence between the predicted and obtained power results for RDD and CRD-Pre relative to the RCT, and (2) power levels in CRD-Pre and RCT that are very close. The study is unique among WSCs for its focus on the correspondence between RCT and observational study standard errors rather than means.

Degradable self-assembling dendrons for gene delivery: experimental and theoretical insights into the barriers to cellular uptake.

PubMed

Barnard, Anna; Posocco, Paola; Pricl, Sabrina; Calderon, Marcelo; Haag, Rainer; Hwang, Mark E; Shum, Victor W T; Pack, Daniel W; Smith, David K

2011-12-21

This paper uses a combined experimental and theoretical approach to gain unique insight into gene delivery. We report the synthesis and investigation of a new family of second-generation dendrons with four triamine surface ligands capable of binding to DNA, degradable aliphatic-ester dendritic scaffolds, and hydrophobic units at their focal points. Dendron self-assembly significantly enhances DNA binding as monitored by a range of experimental methods and confirmed by multiscale modeling. Cellular uptake studies indicate that some of these dendrons are highly effective at transporting DNA into cells (ca. 10 times better than poly(ethyleneimine), PEI). However, levels of transgene expression are relatively low (ca. 10% of PEI). This indicates that these dendrons cannot navigate all of the intracellular barriers to gene delivery. The addition of chloroquine indicates that endosomal escape is not the limiting factor in this case, and it is shown, both experimentally and theoretically, that gene delivery can be correlated with the ability of the dendron assemblies to release DNA. Mass spectrometric assays demonstrate that the dendrons, as intended, do degrade under biologically relevant conditions over a period of hours. Multiscale modeling of degraded dendron structures suggests that complete dendron degradation would be required for DNA release. Importantly, in the presence of the lower pH associated with endosomes, or when bound to DNA, complete degradation of these dendrons becomes ineffective on the transfection time scale-we propose this explains the poor transfection performance of these dendrons. As such, this paper demonstrates that taking this kind of multidisciplinary approach can yield a fundamental insight into the way in which dendrons can navigate barriers to cellular uptake. Lessons learned from this work will inform future dendron design for enhanced gene delivery. © 2011 American Chemical Society

Motivation in Second Language Learning: A Historical Overview and Its Relevance in a Public High School in Pasto, Colombia

ERIC Educational Resources Information Center

Guerrero, Mario

2015-01-01

Motivation has a significant role in the process of language learning. It is important to understand its theoretical evolution in this field to be able to consider its relevance in the learning and teaching of a foreign language. Motivation is a term that is commonly used among language teachers and language learners but perhaps many are not aware…

Adaptive Green-Kubo estimates of transport coefficients from molecular dynamics based on robust error analysis.

PubMed

Jones, Reese E; Mandadapu, Kranthi K

2012-04-21

We present a rigorous Green-Kubo methodology for calculating transport coefficients based on on-the-fly estimates of: (a) statistical stationarity of the relevant process, and (b) error in the resulting coefficient. The methodology uses time samples efficiently across an ensemble of parallel replicas to yield accurate estimates, which is particularly useful for estimating the thermal conductivity of semi-conductors near their Debye temperatures where the characteristic decay times of the heat flux correlation functions are large. Employing and extending the error analysis of Zwanzig and Ailawadi [Phys. Rev. 182, 280 (1969)] and Frenkel [in Proceedings of the International School of Physics "Enrico Fermi", Course LXXV (North-Holland Publishing Company, Amsterdam, 1980)] to the integral of correlation, we are able to provide tight theoretical bounds for the error in the estimate of the transport coefficient. To demonstrate the performance of the method, four test cases of increasing computational cost and complexity are presented: the viscosity of Ar and water, and the thermal conductivity of Si and GaN. In addition to producing accurate estimates of the transport coefficients for these materials, this work demonstrates precise agreement of the computed variances in the estimates of the correlation and the transport coefficient with the extended theory based on the assumption that fluctuations follow a Gaussian process. The proposed algorithm in conjunction with the extended theory enables the calculation of transport coefficients with the Green-Kubo method accurately and efficiently.

Adaptive Green-Kubo estimates of transport coefficients from molecular dynamics based on robust error analysis

NASA Astrophysics Data System (ADS)

Jones, Reese E.; Mandadapu, Kranthi K.

2012-04-01

We present a rigorous Green-Kubo methodology for calculating transport coefficients based on on-the-fly estimates of: (a) statistical stationarity of the relevant process, and (b) error in the resulting coefficient. The methodology uses time samples efficiently across an ensemble of parallel replicas to yield accurate estimates, which is particularly useful for estimating the thermal conductivity of semi-conductors near their Debye temperatures where the characteristic decay times of the heat flux correlation functions are large. Employing and extending the error analysis of Zwanzig and Ailawadi [Phys. Rev. 182, 280 (1969)], 10.1103/PhysRev.182.280 and Frenkel [in Proceedings of the International School of Physics "Enrico Fermi", Course LXXV (North-Holland Publishing Company, Amsterdam, 1980)] to the integral of correlation, we are able to provide tight theoretical bounds for the error in the estimate of the transport coefficient. To demonstrate the performance of the method, four test cases of increasing computational cost and complexity are presented: the viscosity of Ar and water, and the thermal conductivity of Si and GaN. In addition to producing accurate estimates of the transport coefficients for these materials, this work demonstrates precise agreement of the computed variances in the estimates of the correlation and the transport coefficient with the extended theory based on the assumption that fluctuations follow a Gaussian process. The proposed algorithm in conjunction with the extended theory enables the calculation of transport coefficients with the Green-Kubo method accurately and efficiently.

Retrospective reports of attachment disruptions, parental abuse and neglect mediate the relationship between pathological narcissism and self-esteem.

PubMed

Maxwell, Kendal; Huprich, Steven

2014-10-01

Studies have shown a direct relationship between pathological narcissism and self-esteem; however, there have not been many studies that have empirically tested which theoretically relevant variables mediate this relationship. In the present study, we evaluated how self-reported, early negative childhood experiences with parental figures mediate the relationship between pathological narcissism and self-esteem. Four-hundred eight-five undergraduates from a Midwestern university retrospectively assessed their experiences of parental attachment and bonding, as well as their levels of pathological narcissism and current self-esteem. There was a significant correlation among all pathological narcissism subscales and self-esteem, except for the Exploitativeness subscale. Self-esteem was negatively correlated with all negative childhood experiences on the Childhood Trauma Questionnaire (CTQ) and was positively correlated with positive childhood experiences on the Parental Attachment Questionnaire (PAQ). The parental relationship quality was negatively associated with all but one Pathological Narcissism Inventory subscale, as was the PAQ total score. Lastly, emotional neglect on the CTQ significantly mediated the relationship between several pathological narcissism subscales and self-esteem. When investigating parental attachment and parental bonding, the quality of the relationship with the parent was a significant mediator between pathological narcissism and self-esteem. These findings demonstrate the importance of understanding the adverse effects of parental abuse and neglect on healthy development of the self and self-esteem. Clinical implications of these findings are discussed. Copyright © 2014 John Wiley & Sons, Ltd.

Genotype differences in 13C discrimination between atmosphere and leaf matter match differences in transpiration efficiency at leaf and whole-plant levels in hybrid Populus deltoides x nigra.

PubMed

Rasheed, Fahad; Dreyer, Erwin; Richard, Béatrice; Brignolas, Franck; Montpied, Pierre; Le Thiec, Didier

2013-01-01

(13) C discrimination between atmosphere and bulk leaf matter (Δ(13) C(lb) ) is frequently used as a proxy for transpiration efficiency (TE). Nevertheless, its relevance is challenged due to: (1) potential deviations from the theoretical discrimination model, and (2) complex time integration and upscaling from leaf to whole plant. Six hybrid genotypes of Populus deltoides×nigra genotypes were grown in climate chambers and tested for whole-plant TE (i.e. accumulated biomass/water transpired). Net CO(2) assimilation rates (A) and stomatal conductance (g(s) ) were recorded in parallel to: (1) (13) C in leaf bulk material (δ(13) C(lb) ) and in soluble sugars (δ(13) C(ss) ) and (2) (18) O in leaf water and bulk leaf material. Genotypic means of δ(13) C(lb) and δ(13) C(ss) were tightly correlated. Discrimination between atmosphere and soluble sugars was correlated with daily intrinsic TE at leaf level (daily mean A/g(s) ), and with whole-plant TE. Finally, g(s) was positively correlated to (18) O enrichment of bulk matter or water of leaves at individual level, but not at genotype level. We conclude that Δ(13) C(lb) captures efficiently the genetic variability of whole-plant TE in poplar. Nevertheless, scaling from leaf level to whole-plant TE requires to take into account water losses and respiration independent of photosynthesis, which remain poorly documented. © 2012 Blackwell Publishing Ltd.

Using Multiorder Time-Correlation Functions (TCFs) To Elucidate Biomolecular Reaction Pathways from Microsecond Single-Molecule Fluorescence Experiments.

PubMed

Phelps, Carey; Israels, Brett; Marsh, Morgan C; von Hippel, Peter H; Marcus, Andrew H

2016-12-29

Recent advances in single-molecule fluorescence imaging have made it possible to perform measurements on microsecond time scales. Such experiments have the potential to reveal detailed information about the conformational changes in biological macromolecules, including the reaction pathways and dynamics of the rearrangements involved in processes, such as sequence-specific DNA "breathing" and the assembly of protein-nucleic acid complexes. Because microsecond-resolved single-molecule trajectories often involve "sparse" data, that is, they contain relatively few data points per unit time, they cannot be easily analyzed using the standard protocols that were developed for single-molecule experiments carried out with tens-of-millisecond time resolution and high "data density." Here, we describe a generalized approach, based on time-correlation functions, to obtain kinetic information from microsecond-resolved single-molecule fluorescence measurements. This approach can be used to identify short-lived intermediates that lie on reaction pathways connecting relatively long-lived reactant and product states. As a concrete illustration of the potential of this methodology for analyzing specific macromolecular systems, we accompany the theoretical presentation with the description of a specific biologically relevant example drawn from studies of reaction mechanisms of the assembly of the single-stranded DNA binding protein of the T4 bacteriophage replication complex onto a model DNA replication fork.

Psychometrics and life history strategy: the structure and validity of the High K Strategy Scale.

PubMed

Copping, Lee T; Campbell, Anne; Muncer, Steven

2014-03-22

In this paper, we critically review the conceptualization and implementation of psychological measures of life history strategy associated with Differential K theory. The High K Strategy Scale (HKSS: Giosan, 2006) was distributed to a large British sample (n = 809) with the aim of assessing its factor structure and construct validity in relation to theoretically relevant life history variables: age of puberty, age of first sexual encounter, and number of sexual partners. Exploratory and confirmatory factor analyses indicated that the HKSS in its current form did not show an adequate statistical fit to the data. Modifications to improve fit indicated four correlated factors (personal capital, environmental stability, environmental security, and social capital). Later puberty in women was positively associated with measures of the environment and personal capital. Among men, contrary to Differential K predictions but in line with female mate preferences, earlier sexual debut and more sexual partners were positively associated with more favorable environments and higher personal and social capital. We raise concerns about the use of psychometric indicators of lifestyle and personality as proxies for life history strategy when they have not been validated against objective measures derived from contemporary life history theory and when their status as causes, mediators, or correlates has not been investigated.

Statistical fluctuations in pedestrian evacuation times and the effect of social contagion

NASA Astrophysics Data System (ADS)

Nicolas, Alexandre; Bouzat, Sebastián; Kuperman, Marcelo N.

2016-08-01

Mathematical models of pedestrian evacuation and the associated simulation software have become essential tools for the assessment of the safety of public facilities and buildings. While a variety of models is now available, their calibration and test against empirical data are generally restricted to global averaged quantities; the statistics compiled from the time series of individual escapes ("microscopic" statistics) measured in recent experiments are thus overlooked. In the same spirit, much research has primarily focused on the average global evacuation time, whereas the whole distribution of evacuation times over some set of realizations should matter. In the present paper we propose and discuss the validity of a simple relation between this distribution and the microscopic statistics, which is theoretically valid in the absence of correlations. To this purpose, we develop a minimal cellular automaton, with features that afford a semiquantitative reproduction of the experimental microscopic statistics. We then introduce a process of social contagion of impatient behavior in the model and show that the simple relation under test may dramatically fail at high contagion strengths, the latter being responsible for the emergence of strong correlations in the system. We conclude with comments on the potential practical relevance for safety science of calculations based on microscopic statistics.

The Stigma Resistance Scale: A multi-sample validation of a new instrument to assess mental illness stigma resistance.

PubMed

Firmin, Ruth L; Lysaker, Paul H; McGrew, John H; Minor, Kyle S; Luther, Lauren; Salyers, Michelle P

2017-12-01

Although associated with key recovery outcomes, stigma resistance remains under-studied largely due to limitations of existing measures. This study developed and validated a new measure of stigma resistance. Preliminary items, derived from qualitative interviews of people with lived experience, were pilot tested online with people self-reporting a mental illness diagnosis (n = 489). Best performing items were selected, and the refined measure was administered to an independent sample of people with mental illness at two state mental health consumer recovery conferences (n = 202). Confirmatory factor analyses (CFA) guided by theory were used to test item fit, correlations between the refined stigma resistance measure and theoretically relevant measures were examined for validity, and test-retest correlations of a subsample were examined for stability. CFA demonstrated strong fit for a 5-factor model. The final 20-item measure demonstrated good internal consistency for each of the 5 subscales, adequate test-retest reliability at 3 weeks, and strong construct validity (i.e., positive associations with quality of life, recovery, and self-efficacy, and negative associations with overall symptoms, defeatist beliefs, and self-stigma). The new measure offers a more reliable and nuanced assessment of stigma resistance. It may afford greater personalization of interventions targeting stigma resistance. Copyright © 2017 Elsevier B.V. All rights reserved.

[Assessment of psychometric properties of the academic involvement questionnaire, expectations version].

PubMed

Pérez V, Cristhian; Ortiz M, Liliana; Fasce H, Eduardo; Parra P, Paula; Matus B, Olga; McColl C, Peter; Torres A, Graciela; Meyer K, Andrea; Márquez U, Carolina; Ortega B, Javiera

2015-11-01

Academic Involvement Questionnaire, Expectations version (CIA-A), assesses the expectations of involvement in studies. It is a relevant predictor of student success. However, the evidence of its validity and reliability in Chile is low, and in the case of Medical students, there is no evidence at all. To evaluate the factorial structure and internal consistency of the CIA-A in Chilean Medical school freshmen. The survey was applied to 340 Medicine freshmen, chosen by non-probability quota sampling. They answered a back-translated version of CIA-A from Portuguese to Spanish, plus a sociodemographic questionnaire. For psychometric analysis of the CIA-A, an exploratory factor analysis was carried on, the reliability of the factors was calculated, a descriptive analysis was conducted and their correlation was assessed. Five factors were identified: vocational, institutional and social involvement, use of resources and student participation. Their reliabilities ranged between Cronbach's alpha values of 0.71 to 0.87. Factors also showed statistically significant correlations between each other. Identified factor structure is theoretically consistent with the structure of original version. It just disagrees in one factor. In addition, the factors' internal consistency were adequate for using them in research. This supports the construct validity and reliability of the CIA-A to assess involvement expectations in medical school freshmen.

Repelling Point Bosons

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGuire, J. B.

2011-12-01

There is a body of conventional wisdom that holds that a solvable quantum problem, by virtue of its solvability, is pathological and thus irrelevant. It has been difficult to refute this view owing to the paucity of theoretical constructs and experimental results. Recent experiments involving equivalent ions trapped in a spatial conformation of extreme anisotropic confinement (longitudinal extension tens, hundreds or even thousands of times transverse extension) have modified the view of relevancy, and it is now possible to consider systems previously thought pathological, in particular point Bosons that repel in one dimension. It has been difficult for the experimentalistsmore » to utilize existing theory, mainly due to long-standing theoretical misunderstanding of the relevance of the permutation group, in particular the non-commutativity of translations (periodicity) and transpositions (permutation). This misunderstanding is most easily rectified in the case of repelling Bosons.« less

The Biological Relevance of Artificial Life: Lessons from Artificial Intelligence

NASA Technical Reports Server (NTRS)

Colombano, Silvano

2000-01-01

There is no fundamental reason why A-life couldn't simply be a branch of computer science that deals with algorithms that are inspired by, or emulate biological phenomena. However, if these are the limits we place on this field, we miss the opportunity to help advance Theoretical Biology and to contribute to a deeper understanding of the nature of life. The history of Artificial Intelligence provides a good example, in that early interest in the nature of cognition quickly was lost to the process of building tools, such as "expert systems" that, were certainly useful, but provided little insight in the nature of cognition. Based on this lesson, I will discuss criteria for increasing the biological relevance of A-life and the probability that this field may provide a theoretical foundation for Biology.

Density functional theory and phytochemical study of 8-hydroxyisodiospyrin

NASA Astrophysics Data System (ADS)

Ullah, Zakir; Ata-ur-Rahman; Fazl-i-Sattar; Rauf, Abdur; Yaseen, Muhammad; Hassan, Waseem; Tariq, Muhammad; Ayub, Khurshid; Tahir, Asif Ali; Ullah, Habib

2015-09-01

Comprehensive theoretical and experimental studies of a natural product, 8-hydroxyisodiospyrin (HDO) have been carried out. Based on the correlation of experimental and theoretical data, an appropriate computational model was developed for obtaining the electronic, spectroscopic, and thermodynamic parameters of HDO. First of all, the exact structure of HDO is confirmed from the nice correlation of theory and experiment, prior to determination of its electroactive nature. Hybrid density functional theory (DFT) is employed for all theoretical simulations. The experimental and predicted IR and UV-vis spectra [B3LYP/6-31+G(d,p) level of theory] have excellent correlation. Inter-molecular non-covalent interaction of HDO with different gases such as NH3, CO2, CO, H2O is investigated through geometrical counterpoise (gCP) i.e., B3LYP-gCP-D3/6-31G∗ method. Furthermore, the inter-molecular interaction is also supported by geometrical parameters, electronic properties, thermodynamic parameters and charge analysis. All these characterizations have corroborated each other and confirmed the electroactive nature (non-covalent interaction ability) of HDO for the studied gases. Electronic properties such as Ionization Potential (IP), Electron Affinities (EA), electrostatic potential (ESP), density of states (DOS), HOMO, LUMO, and band gap of HDO have been estimated for the first time theoretically.

Further Theoretical Insight into the Mechanical Properties of Polycaprolactone Loaded with Organic–Inorganic Hybrid Fillers

PubMed Central

Maietta, Saverio; Russo, Teresa; De Santis, Roberto; Ronca, Dante; Riccardi, Filomena; Martorelli, Massimo; Gloria, Antonio

2018-01-01

Experimental/theoretical analyses have already been performed on poly(ε-caprolactone) (PCL) loaded with organic–inorganic fillers (PCL/TiO2 and PCL/ZrO2) to find a correlation between the results from the small punch test and Young’s modulus of the materials. PCL loaded with Ti2 (PCL = 12, TiO2 = 88 wt %) and Zr2 (PCL = 12, ZrO2 = 88 wt %) hybrid fillers showed better performances than those obtained for the other particle composition. In this context, the aim of current research is to provide further insight into the mechanical properties of PCL loaded with sol–gel-synthesized organic–inorganic hybrid fillers for bone tissue engineering. For this reason, theoretical analyses were performed by the finite element method. The results from the small punch test and Young’s modulus of the materials were newly correlated. The obtained values of Young’s modulus (193 MPa for PCL, 378 MPa for PCL/Ti2 and 415 MPa for PCL/Zr2) were higher than those obtained from a previous theoretical modelling (144 MPa for PCL, 282 MPa for PCL/Ti2 and 310 MPa for PCL/Zr2). This correlation will be an important step for the evaluation of Young’s modulus, starting from the small punch test data. PMID:29466299

Further Theoretical Insight into the Mechanical Properties of Polycaprolactone Loaded with Organic-Inorganic Hybrid Fillers.

PubMed

Maietta, Saverio; Russo, Teresa; Santis, Roberto De; Ronca, Dante; Riccardi, Filomena; Catauro, Michelina; Martorelli, Massimo; Gloria, Antonio

2018-02-21

Experimental/theoretical analyses have already been performed on poly(ε-caprolactone) (PCL) loaded with organic-inorganic fillers (PCL/TiO₂ and PCL/ZrO₂) to find a correlation between the results from the small punch test and Young's modulus of the materials. PCL loaded with Ti2 (PCL = 12, TiO₂ = 88 wt %) and Zr2 (PCL = 12, ZrO₂ = 88 wt %) hybrid fillers showed better performances than those obtained for the other particle composition. In this context, the aim of current research is to provide further insight into the mechanical properties of PCL loaded with sol-gel-synthesized organic-inorganic hybrid fillers for bone tissue engineering. For this reason, theoretical analyses were performed by the finite element method. The results from the small punch test and Young's modulus of the materials were newly correlated. The obtained values of Young's modulus (193 MPa for PCL, 378 MPa for PCL/Ti2 and 415 MPa for PCL/Zr2) were higher than those obtained from a previous theoretical modelling (144 MPa for PCL, 282 MPa for PCL/Ti2 and 310 MPa for PCL/Zr2). This correlation will be an important step for the evaluation of Young's modulus, starting from the small punch test data.

Electronic structure of disordered CuPd alloys: A two-dimensional positron-annihilation study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smedskjaer, L.C.; Benedek, R.; Siegel, R.W.

1987-11-23

Two-dimensional--angular-correlation experiments using posi- tron-annihilation spectroscopy were performed on a series of disordered Cu-rich CuPd-alloy single crystals. The results are compared with theoretical calculations based on the Korringa-Kohn-Rostoker coherent-potential approximation. Our experiments confirm the theoretically predicted flattening of the alloy Fermi surface near (110) with increasing Pd concentration. The momentum densities and the two-dimensional--angular-correlation spectra around zero momentum exhibit a characteristic signature of the electronic states near the valence-band edge in the alloy.

Theoretical analysis on the measurement errors of local 2D DIC: Part I temporal and spatial uncertainty quantification of displacement measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yueqi; Lava, Pascal; Reu, Phillip

This study presents a theoretical uncertainty quantification of displacement measurements by subset-based 2D-digital image correlation. A generalized solution to estimate the random error of displacement measurement is presented. The obtained solution suggests that the random error of displacement measurements is determined by the image noise, the summation of the intensity gradient in a subset, the subpixel part of displacement, and the interpolation scheme. The proposed method is validated with virtual digital image correlation tests.

Theoretical analysis on the measurement errors of local 2D DIC: Part I temporal and spatial uncertainty quantification of displacement measurements

DOE PAGES

Wang, Yueqi; Lava, Pascal; Reu, Phillip; ...

2015-12-23

This study presents a theoretical uncertainty quantification of displacement measurements by subset-based 2D-digital image correlation. A generalized solution to estimate the random error of displacement measurement is presented. The obtained solution suggests that the random error of displacement measurements is determined by the image noise, the summation of the intensity gradient in a subset, the subpixel part of displacement, and the interpolation scheme. The proposed method is validated with virtual digital image correlation tests.

Finite size effects on the experimental observables of the Glauber model: a theoretical and experimental investigation

NASA Astrophysics Data System (ADS)

Vindigni, A.; Bogani, L.; Gatteschi, D.; Sessoli, R.; Rettori, A.; Novak, M. A.

2004-05-01

We investigate the relaxation time, τ, of a dilute Glauber kinetic Ising chain obtained by ac susceptibility and SQUID magnetometry on a Co(II)-organic radical Ising 1D ferrimagnet doped with Zn(II). Theoretically we predicted a crossover in the temperature-dependence of τ, when the average segment is of the same order of the correlation length. Comparing the experimental results with theory we conclude that in the investigted temperature range the correlation length exceeds the finite length also in the pure sample.

Supersonic wings with significant leading-edge thrust at cruise

NASA Technical Reports Server (NTRS)

Robins, A. W.; Carlson, H. W.; Mack, R. J.

1980-01-01

Experimental/theoretical correlations are presented which show that significant levels of leading edge thrust are possible at supersonic speeds for certain planforms which match the theoretical thrust distribution potential with the supporting airfoil geometry. The analytical process employed spanwise distribution of both it and/or that component of full theoretical thrust which acts as vortex lift. Significantly improved aerodynamic performance in the moderate supersonic speed regime is indicated.

Reveal quantum correlation in complementary bases

PubMed Central

Wu, Shengjun; Ma, Zhihao; Chen, Zhihua; Yu, Sixia

2014-01-01

An essential feature of genuine quantum correlation is the simultaneous existence of correlation in complementary bases. We reveal this feature of quantum correlation by defining measures based on invariance under a basis change. For a bipartite quantum state, the classical correlation is the maximal correlation present in a certain optimum basis, while the quantum correlation is characterized as a series of residual correlations in the mutually unbiased bases. Compared with other approaches to quantify quantum correlation, our approach gives information-theoretical measures that directly reflect the essential feature of quantum correlation. PMID:24503595

A study on the correlation between the dewetting temperature of Ag film and SERS intensity.

PubMed

Quan, Jiamin; Zhang, Jie; Qi, Xueqiang; Li, Junying; Wang, Ning; Zhu, Yong

2017-11-07

The thermally dewetted metal nano-islands have been actively investigated as cost-effective SERS-active substrates with a large area, good reproducibility and repeatability via simple fabrication process. However, the correlation between the dewetting temperature of metal film and SERS intensity hasn't been systematically studied. In this work, taking Ag nano-islands (AgNIs) as an example, we reported a strategy to investigate the correlation between the dewetting temperature of metal film and SERS intensity. We described the morphology evolution of AgNIs on the SiO 2 planar substrate in different temperatures and got the quantitative information in surface-limited diffusion process (SLDP) as a function of annealing temperature via classical mean-field nucleation theory. Those functions were further used in the simulation of electromagnetic field to obtain the correlation between the dewetting temperature of Ag film and theoretical analysis. In addition, Raman mapping was done on samples annealed at different temperatures, with R6G as an analyte, to accomplish the analysis of the correlation between the dewetting temperature of Ag film and SERS intensity, which is consistent with the theoretical analysis. For SLDP, we used the morphological characterization of five samples prepared by different annealing temperatures to successfully illustrate the change in SERS intensity with the temperature fluctuation, obtaining a small deviation between the experimental results and theoretic prediction.

Locally optimum nonlinearities for DCT watermark detection.

PubMed

Briassouli, Alexia; Strintzis, Michael G

2004-12-01

The issue of copyright protection of digital multimedia data has attracted a lot of attention during the last decade. An efficient copyright protection method that has been gaining popularity is watermarking, i.e., the embedding of a signature in a digital document that can be detected only by its rightful owner. Watermarks are usually blindly detected using correlating structures, which would be optimal in the case of Gaussian data. However, in the case of DCT-domain image watermarking, the data is more heavy-tailed and the correlator is clearly suboptimal. Nonlinear receivers have been shown to be particularly well suited for the detection of weak signals in heavy-tailed noise, as they are locally optimal. This motivates the use of the Gaussian-tailed zero-memory nonlinearity, as well as the locally optimal Cauchy nonlinearity for the detection of watermarks in DCT transformed images. We analyze the performance of these schemes theoretically and compare it to that of the traditionally used Gaussian correlator, but also to the recently proposed generalized Gaussian detector, which outperforms the correlator. The theoretical analysis and the actual performance of these systems is assessed through experiments, which verify the theoretical analysis and also justify the use of nonlinear structures for watermark detection. The performance of the correlator and the nonlinear detectors in the presence of quantization is also analyzed, using results from dither theory, and also verified experimentally.

Numerical calculation of aerodynamics wind turbine blade S809 airfoil and comparison of theoretical calculations with experimental measurements and confirming with NREL data

NASA Astrophysics Data System (ADS)

Sogukpinar, Haci; Bozkurt, Ismail

2018-02-01

Aerodynamic performance of the airfoil plays the most important role to obtain economically maximum efficiency from a wind turbine. Therefore airfoil should have an ideal aerodynamic shape. In this study, aerodynamic simulation of S809 airfoil is conducted and obtained result compared with previously made NASA experimental result and NREL theoretical data. At first, Lift coefficient, lift to drag ratio and pressure coefficient around S809 airfoil are calculated with SST turbulence model, and are compared with experimental and other theoretical data to correlate simulation correctness of the computational approaches. And result indicates good correlation with both experimental and theoretical data. This calculation point out that as the increasing relative velocity, lift to drag ratio increases. Lift to drag ratio attain maximum at the angle around 6 degree and after that starts to decrease again. Comparison shows that CFD code used in this calculation can predict aerodynamic properties of airfoil.

Is the Life Space Assessment applicable to a palliative care population? Its relationship to measures of performance and quality of life.

PubMed

Phillips, Jane Louise; Lam, Lawrence; Luckett, Tim; Agar, Meera; Currow, David

2014-06-01

The spatial environments that palliative care patients frequent for business and leisure constrict as their disease progresses and their physical functioning deteriorates. Measuring a person's movement within his or her own environment is a clinically relevant and patient-centered outcome because it measures function in a way that reflects actual and not theoretical participation. This exploratory study set out to test whether the Life-Space Assessment (LSA) would correlate with other commonly used palliative care outcome measures of function and quality of life. The baseline LSA, Australia-modified Karnofsky Performance Status Scale (AKPS), and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 15-Palliative (EORTC QLQ-C15-PAL) scores from two large clinical trials were used to calculate correlation coefficients between the measures. Convergent validity analysis was undertaken by comparing LSA scores between participants with higher (≥70) and lower (≤60) AKPS scores. The LSA was correlated significantly and positively with the AKPS, with a moderate correlation coefficient of 0.54 (P<0.001). There was a significant weak negative correlation between the LSA and the EORTC QLQ-C15-PAL, with a small coefficient of -0.22 (P=0.027), but a strong correlation between the LSA and the EORTC QLQ-C15-PAL item related to independent activities of daily living (r=-0.654, P<0.01). A significant difference in the LSA score between participants with higher (≥70) and lower (≤60) AKPS scores t(97)=-4.35, P<0.001) was found. The LSA appears applicable to palliative care populations given the convergent validity and capacity of this instrument to differentiate a person's ability to move through life-space zones by performance status. Further research is required to validate and apply the LSA within community palliative care populations. Copyright © 2014 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

Microbubbles and Microparticles are Not Faithful Tracers of Turbulent Acceleration

NASA Astrophysics Data System (ADS)

Mathai, Varghese; Calzavarini, Enrico; Brons, Jon; Sun, Chao; Lohse, Detlef

2016-07-01

We report on the Lagrangian statistics of acceleration of small (sub-Kolmogorov) bubbles and tracer particles with Stokes number St ≪1 in turbulent flow. At a decreasing Reynolds number, the bubble accelerations show deviations from that of tracer particles; i.e., they deviate from the Heisenberg-Yaglom prediction and show a quicker decorrelation despite their small size and minute St. Using direct numerical simulations, we show that these effects arise due the drift of these particles through the turbulent flow. We theoretically predict this gravity-driven effect for developed isotropic turbulence, with the ratio of Stokes to Froude number or equivalently the particle drift velocity governing the enhancement of acceleration variance and the reductions in correlation time and intermittency. Our predictions are in good agreement with experimental and numerical results. The present findings are relevant to a range of scenarios encompassing tiny bubbles and droplets that drift through the turbulent oceans and the atmosphere. They also question the common usage of microbubbles and microdroplets as tracers in turbulence research.

How do illness-anxious individuals process health-threatening information? A systematic review of evidence for the cognitive-behavioral model.

PubMed

Leonidou, Chrysanthi; Panayiotou, Georgia

2018-08-01

According to the cognitive-behavioral model, illness anxiety is developed and maintained through biased processing of health-threatening information and maladaptive responses to such information. This study is a systematic review of research that attempted to validate central tenets of the cognitive-behavioral model regarding etiological and maintenance mechanisms in illness anxiety. Sixty-two studies, including correlational and experimental designs, were identified through a systematic search of databases and were evaluated for their quality. Outcomes were synthesized following a qualitative thematic approach under categories of theoretically driven mechanisms derived from the cognitive-behavioral model: attention, memory and interpretation biases, perceived awareness and inaccuracy in perception of somatic sensations, negativity bias, emotion dysregulation, and behavioral avoidance. Findings partly support the cognitive-behavioral model, but several of its hypothetical mechanisms only receive weak support due to the scarcity of relevant studies. Directions for future research are suggested based on identified gaps in the existing literature. Copyright © 2018 Elsevier Inc. All rights reserved.

How Do DSM-5 Personality Traits Align With Schema Therapy Constructs?

PubMed

Bach, Bo; Lee, Christopher; Mortensen, Erik Lykke; Simonsen, Erik

2016-08-01

DSM-5 offers an alternative model of personality pathology that includes 25 traits. Although personality disorders are mostly treated with psychotherapy, the correspondence between DSM-5 traits and concepts in evidence-based psychotherapy has not yet been evaluated adequately. Suitably, schema therapy was developed for treating personality disorders, and it has achieved promising evidence. The authors examined associations between DSM-5 traits and schema therapy constructs in a mixed sample of 662 adults, including 312 clinical participants. Associations were investigated in terms of factor loadings and regression coefficients in relation to five domains, followed by specific correlations among all constructs. The results indicated conceptually coherent associations, and 15 of 25 traits were strongly related to relevant schema therapy constructs. Conclusively, DSM-5 traits may be considered expressions of schema therapy constructs, which psychotherapists might take advantage of in terms of case formulation and targets of treatment. In turn, schema therapy constructs add theoretical understanding to DSM-5 traits.

Using RIXS to uncover elementary charge and spin excitations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jia, Chunjing; Wohlfeld, Krzysztof; Wang, Yao

2016-05-13

Despite significant progress in resonant inelastic x-ray scattering (RIXS) experiments on cuprates at the Cu L-edge, a theoretical understanding of the cross section remains incomplete in terms of elementary excitations and the connection to both charge and spin structure factors. Here, we use state-of-the-art, unbiased numerical calculations to study the low-energy excitations probed by RIXS in the Hubbard model, relevant to the cuprates. The results highlight the importance of scattering geometry, in particular, both the incident and scattered x-ray photon polarization, and they demonstrate that on a qualitative level the RIXS spectral shape in the cross-polarized channel approximates that ofmore » the spin dynamical structure factor. Furthermore, in the parallel-polarized channel, the complexity of the RIXS process beyond a simple two-particle response complicates the analysis and demonstrates that approximations and expansions that attempt to relate RIXS to less complex correlation functions cannot reproduce the full diversity of RIXS spectral features.« less

Optimal antibunching in passive photonic devices based on coupled nonlinear resonators

NASA Astrophysics Data System (ADS)

Ferretti, S.; Savona, V.; Gerace, D.

2013-02-01

We propose the use of weakly nonlinear passive materials for prospective applications in integrated quantum photonics. It is shown that strong enhancement of native optical nonlinearities by electromagnetic field confinement in photonic crystal resonators can lead to single-photon generation only exploiting the quantum interference of two coupled modes and the effect of photon blockade under resonant coherent driving. For realistic system parameters in state of the art microcavities, the efficiency of such a single-photon source is theoretically characterized by means of the second-order correlation function at zero-time delay as the main figure of merit, where major sources of loss and decoherence are taken into account within a standard master equation treatment. These results could stimulate the realization of integrated quantum photonic devices based on non-resonant material media, fully integrable with current semiconductor technology and matching the relevant telecom band operational wavelengths, as an alternative to single-photon nonlinear devices based on cavity quantum electrodynamics with artificial atoms or single atomic-like emitters.

The Deceptively Simple N170 Reflects Network Information Processing Mechanisms Involving Visual Feature Coding and Transfer Across Hemispheres

PubMed Central

Ince, Robin A. A.; Jaworska, Katarzyna; Gross, Joachim; Panzeri, Stefano; van Rijsbergen, Nicola J.; Rousselet, Guillaume A.; Schyns, Philippe G.

2016-01-01

A key to understanding visual cognition is to determine “where”, “when”, and “how” brain responses reflect the processing of the specific visual features that modulate categorization behavior—the “what”. The N170 is the earliest Event-Related Potential (ERP) that preferentially responds to faces. Here, we demonstrate that a paradigmatic shift is necessary to interpret the N170 as the product of an information processing network that dynamically codes and transfers face features across hemispheres, rather than as a local stimulus-driven event. Reverse-correlation methods coupled with information-theoretic analyses revealed that visibility of the eyes influences face detection behavior. The N170 initially reflects coding of the behaviorally relevant eye contralateral to the sensor, followed by a causal communication of the other eye from the other hemisphere. These findings demonstrate that the deceptively simple N170 ERP hides a complex network information processing mechanism involving initial coding and subsequent cross-hemispheric transfer of visual features. PMID:27550865

Real Spin Glasses Relax Slowly in the Shade of Hierarchical Trees

NASA Astrophysics Data System (ADS)

Vincent, E.; Hammann, J.; Ocio, M.

2009-06-01

The Parisi solution of the mean-field spin glass has been widely accepted and celebrated. Its marginal stability in 3d and its complexity however raised the question of its relevance to real spin glasses. This paper gives a short overview of the important experimental results which could be understood within the mean-field solution. The existence of a true phase transition and the particular behaviour of the susceptibility below the freezing temperature, predicted by the theory, are clearly confirmed by the experimental results. The behaviour of the complex order parameter and of the Fluctuation Dissipation ratio are in good agreement with results of spontaneous noise measurements. The very particular ultrametric symmetry, the key feature of the theory, provided us with a simple description of the rejuvenation and memory effects observed in experiment. Finally, going a step beyond mean-field, the paper shortly discusses new analyses in terms of correlated domains characterized by their length scales, as well as new experiments on superspin glasses which compare well with recent theoretical simulations.

NGF and romantic love.

PubMed

Emanuele, Enzo

2011-06-01

Romantic love is the catalyst behind the spread of the human life. The neurobiology of love embraces the hypothesis that what we call "romantic attachment" or "romantic love" may be at least in part the expression of biological factors. A corollary of this hypothesis states that it is possible to learn much about the nature of human love by studying the molecules involved in the expression of social and affiliative behaviours. Under this theoretical framework, we have investigated the changes in plasma neurotrophin levels in subjects with early stage romantic love. A positive association between the intensity of early romantic feelings and serum levels of nerve growth factor (NGF) has been identified. These findings link love with biologically relevant pathways for neuron survival and illuminate the biochemical correlates of such a complex feeling that so deeply affects our own lives. The progresses in the neurobiology of love suggest that this kind of research may open a new window onto our understanding of the very nature of human romantic bonding.

A quantitative and spatially resolved analysis of the performance-bottleneck in high efficiency, planar hybrid perovskite solar cells

DOE PAGES

Draguta, Sergiu; Christians, Jeffrey A.; Morozov, Yurii V.; ...

2018-01-01

Hybrid perovskites represent a potential paradigm shift for the creation of low-cost solar cells. Current power conversion efficiencies (PCEs) exceed 22%. However, despite this, record PCEs are still far from their theoretical Shockley–Queisser limit of 31%. To increase these PCE values, there is a pressing need to understand, quantify and microscopically model charge recombination processes in full working devices. Here, we present a complete microscopic account of charge recombination processes in high efficiency (18–19% PCE) hybrid perovskite (mixed cation and methylammonium lead iodide) solar cells. We employ diffraction-limited optical measurements along with relevant kinetic modeling to establish, for the firstmore » time, local photoluminescence quantum yields, trap densities, trapping efficiencies, charge extraction efficiencies, quasi-Fermi-level splitting, and effective PCE estimates. Correlations between these spatially resolved parameters, in turn, allow us to conclude that intrinsic electron traps in the perovskite active layers limit the performance of these state-of-the-art hybrid perovskite solar cells.« less

Scanning tunnelling spectroscopy as a probe of multi-Q magnetic states of itinerant magnets

DOE PAGES

Gastiasoro, Maria N.; Eremin, Ilya; Fernandes, Rafael M.; ...

2017-02-08

The combination of electronic correlations and Fermi surfaces with multiple nesting vectors can lead to the appearance of complex multi-Q magnetic ground states, hosting unusual states such as chiral density waves and quantum Hall insulators. Distinguishing single-Q and multi-Q magnetic phases is however a notoriously difficult experimental problem. Here we propose theoretically that the local density of states (LDOS) near a magnetic impurity, whose orientation may be controlled by an external magnetic field, can be used to map out the detailed magnetic configuration of an itinerant system and distinguish unambiguously between single-Q and multi-Q phases. We demonstrate this concept bymore » computing and contrasting the LDOS near a magnetic impurity embedded in three different magnetic ground states relevant to iron-based superconductors—one single-Q and two double-Q phases. Our results open a promising avenue to investigate the complex magnetic configurations in itinerant systems via standard scanning tunnelling spectroscopy, without requiring spin-resolved capability.« less

Anti-transgender prejudice: a structural equation model of associated constructs.

PubMed

Tebbe, Esther N; Moradi, Bonnie

2012-04-01

This study aimed to identify theoretically relevant key correlates of anti-transgender prejudice. Specifically, structural equation modeling was used to test the unique relations of anti-lesbian, gay, and bisexual (LGB) prejudice; traditional gender role attitudes; need for closure; and social dominance orientation with anti-transgender prejudice. Social desirability was controlled as a covariate in the model. Analyses of data from 250 undergraduate students indicated that anti-LGB prejudice, traditional gender role attitudes, and need for closure each had positive unique relations with anti-transgender prejudice beyond the negative association of social desirability with such prejudice. By contrast, social dominance orientation was not related uniquely to anti-transgender prejudice. Additional analyses indicated that women's mean level of anti-transgender prejudice was lower than that of men's, but the pattern of relations between the predictor variables and anti-transgender prejudice did not differ between women and men. A confirmatory factor analysis also supported the unidimensional structure of anti-transgender prejudice as operationalized by Nagoshi et al.'s (2008) Transphobia Scale.

Conscientiousness and (un)healthy eating: the role of impulsive eating and age in the consumption of daily main meals.

PubMed

Olsen, Svein Ottar; Tuu, Ho Huy; Honkanen, Pirjo; Verplanken, Bas

2015-08-01

The present study aims to explore the relationship between conscientiousness and the consumption of healthy versus unhealthy main meals. Impulsive eating was tested as a mediator in this relationship, as well as direct effects of age on those constructs. A nationwide representative sample of 1,006 Norwegian adults (18-70 years) within a prospective design was used to test a theoretical model. The structural equation model (SEM), in combination with bootstrapping procedures in AMOS, was the principal analytical method. Conscientiousness was negatively associated with unhealthy and impulsive eating. Impulsive eating was a partial mediator between conscientiousness and unhealthy eating and a full mediator between conscientiousness and healthy eating. Age was positively correlated with conscientiousness and this relationship had an inverted U-shape form. Finally, age was negatively associated with unhealthy and impulsive eating, and positively associated with healthy eating. This study confirmed the relevance of conscientiousness for healthy, unhealthy, and impulsive eating. © 2015 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

The psychometric properties of the Portuguese version of the Personality Inventory for DSM-5.

PubMed

Pires, Rute; Sousa Ferreira, Ana; Guedes, David

2017-10-01

The DSM-5 Section III proposes a hybrid dimensional-categorical model of conceptualizing personality and its disorders that includes assessment of impairments in personality functioning (criterion A) and maladaptive personality traits (criterion B). The Personality Inventory for the DSM-5 is a new dimensional tool, composed of 220 items organized into 25 facets that delineate five higher order domains of clinically relevant personality differences, and was developed to operationalize the DSM-5 model of pathological personality traits. The current studies address the internal consistency (study 1), the test-retest reliability (study 2) and the criterion validity (studies 3 and 4) of the Portuguese version of the PID-5 in samples of native speaking psychology students. Results indicated good internal consistency reliabilities and good temporal stability reliabilities for the majority of the PID-5 traits. The correlational pattern of the PID-5 traits with two measures of personality was in accordance with theoretical expectations and showed its concurrent validity. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

A note on generalized Genome Scan Meta-Analysis statistics

PubMed Central

Koziol, James A; Feng, Anne C

2005-01-01

Background Wise et al. introduced a rank-based statistical technique for meta-analysis of genome scans, the Genome Scan Meta-Analysis (GSMA) method. Levinson et al. recently described two generalizations of the GSMA statistic: (i) a weighted version of the GSMA statistic, so that different studies could be ascribed different weights for analysis; and (ii) an order statistic approach, reflecting the fact that a GSMA statistic can be computed for each chromosomal region or bin width across the various genome scan studies. Results We provide an Edgeworth approximation to the null distribution of the weighted GSMA statistic, and, we examine the limiting distribution of the GSMA statistics under the order statistic formulation, and quantify the relevance of the pairwise correlations of the GSMA statistics across different bins on this limiting distribution. We also remark on aggregate criteria and multiple testing for determining significance of GSMA results. Conclusion Theoretical considerations detailed herein can lead to clarification and simplification of testing criteria for generalizations of the GSMA statistic. PMID:15717930

Recollections of Emotional Abuse and Neglect in Childhood as Risk Factors for Depressive Disorders and the Need for Psychotherapy in Adult Life.

PubMed

Neumann, Eva

2017-11-01

Theoretical and empirical works have pointed out that depression comes along with adverse interpersonal experiences in childhood and adult life. The purpose of this study was to explore whether past and current experiences differ in their relevance for depression. A clinical group of 80 psychotherapy patients diagnosed with a depressive disorder was contrasted with a control group of 111 nondepressed patients from somatic facilities. Child abuse, neglect, and adult attachment dimensions were measured with self-report scales. Depression was correlated with emotional abuse, neglect, and attachment anxiety. However, solely emotional abuse and neglect significantly predicted the probability to be in the group of depressed patients, whereas attachment anxiety did not contribute to this prediction. The findings reveal that childhood variables, namely, recollections of emotional traumas, are more closely associated with depression than representations of adult attachment bonds and therefore need special attention in the psychotherapeutic treatment of depressive disorders.

Holon Wigner Crystal in a Lightly Doped Kagome Quantum Spin Liquid

DOE PAGES

Jiang, Hong -Chen; Devereaux, T.; Kivelson, S. A.

2017-08-07

We address the problem of a lightly doped spin liquid through a large-scale density-matrix renormalization group study of the t–J model on a kagome lattice with a small but nonzero concentration δ of doped holes. It is now widely accepted that the undoped (δ = 0) spin-1/2 Heisenberg antiferromagnet has a spin-liquid ground state. Theoretical arguments have been presented that light doping of such a spin liquid could give rise to a high temperature superconductor or an exotic topological Fermi liquid metal. Instead, we infer that the doped holes form an insulating charge-density wave state with one doped hole permore » unit cell, i.e., a Wigner crystal. Spin correlations remain short ranged, as in the spin-liquid parent state, from which we infer that the state is a crystal of spinless holons, rather than of holes. In conclusion, our results may be relevant to kagome lattice herbertsmithite upon doping.« less

A quantitative and spatially resolved analysis of the performance-bottleneck in high efficiency, planar hybrid perovskite solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Draguta, Sergiu; Christians, Jeffrey A.; Morozov, Yurii V.

Hybrid perovskites represent a potential paradigm shift for the creation of low-cost solar cells. Current power conversion efficiencies (PCEs) exceed 22%. However, despite this, record PCEs are still far from their theoretical Shockley–Queisser limit of 31%. To increase these PCE values, there is a pressing need to understand, quantify and microscopically model charge recombination processes in full working devices. Here, we present a complete microscopic account of charge recombination processes in high efficiency (18–19% PCE) hybrid perovskite (mixed cation and methylammonium lead iodide) solar cells. We employ diffraction-limited optical measurements along with relevant kinetic modeling to establish, for the firstmore » time, local photoluminescence quantum yields, trap densities, trapping efficiencies, charge extraction efficiencies, quasi-Fermi-level splitting, and effective PCE estimates. Correlations between these spatially resolved parameters, in turn, allow us to conclude that intrinsic electron traps in the perovskite active layers limit the performance of these state-of-the-art hybrid perovskite solar cells.« less

The development and validation of the Relational Self-Esteem Scale.

PubMed

Du, Hongfei; King, Ronnel B; Chi, Peilian

2012-06-01

According to the tripartite model of the self (Brewer & Gardner, 1996), the self consists of three aspects: personal, relational, and collective. Correspondingly, individuals can achieve a sense of self-worth through their personal attributes (personal self-esteem), relationship with significant others (relational self-esteem), or social group membership (collective self-esteem). Existing measures on personal and collective self-esteem are available in the literature; however, no scale exists that assesses relational self-esteem. The authors developed a scale to measure individual differences in relational self-esteem and tested it with two samples of Chinese university students. Between and within-network approaches to construct validation were used. The scale showed adequate internal consistency reliability and results of the confirmatory factor analysis showed good fit. It also exhibited meaningful correlations with theoretically relevant constructs in the nomological network. Implications and directions for future research are discussed. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

The Representation of Prediction Error in Auditory Cortex

PubMed Central

Rubin, Jonathan; Ulanovsky, Nachum; Tishby, Naftali

2016-01-01

To survive, organisms must extract information from the past that is relevant for their future. How this process is expressed at the neural level remains unclear. We address this problem by developing a novel approach from first principles. We show here how to generate low-complexity representations of the past that produce optimal predictions of future events. We then illustrate this framework by studying the coding of ‘oddball’ sequences in auditory cortex. We find that for many neurons in primary auditory cortex, trial-by-trial fluctuations of neuronal responses correlate with the theoretical prediction error calculated from the short-term past of the stimulation sequence, under constraints on the complexity of the representation of this past sequence. In some neurons, the effect of prediction error accounted for more than 50% of response variability. Reliable predictions often depended on a representation of the sequence of the last ten or more stimuli, although the representation kept only few details of that sequence. PMID:27490251

Computational Model of Population Dynamics Based on the Cell Cycle and Local Interactions

NASA Astrophysics Data System (ADS)

Oprisan, Sorinel Adrian; Oprisan, Ana

2005-03-01

Our study bridges cellular (mesoscopic) level interactions and global population (macroscopic) dynamics of carcinoma. The morphological differences and transitions between well and smooth defined benign tumors and tentacular malignat tumors suggest a theoretical analysis of tumor invasion based on the development of mathematical models exhibiting bifurcations of spatial patterns in the density of tumor cells. Our computational model views the most representative and clinically relevant features of oncogenesis as a fight between two distinct sub-systems: the immune system of the host and the neoplastic system. We implemented the neoplastic sub-system using a three-stage cell cycle: active, dormant, and necrosis. The second considered sub-system consists of cytotoxic active (effector) cells — EC, with a very broad phenotype ranging from NK cells to CTL cells, macrophages, etc. Based on extensive numerical simulations, we correlated the fractal dimensions for carcinoma, which could be obtained from tumor imaging, with the malignat stage. Our computational model was able to also simulate the effects of surgical, chemotherapeutical, and radiotherapeutical treatments.

Thermalization and prethermalization in isolated quantum systems: a theoretical overview

NASA Astrophysics Data System (ADS)

Mori, Takashi; Ikeda, Tatsuhiko N.; Kaminishi, Eriko; Ueda, Masahito

2018-06-01

The approach to thermal equilibrium, or thermalization, in isolated quantum systems is among the most fundamental problems in statistical physics. Recent theoretical studies have revealed that thermalization in isolated quantum systems has several remarkable features, which emerge from quantum entanglement and are quite distinct from those in classical systems. Experimentally, well isolated and highly controllable ultracold quantum gases offer an ideal testbed to study the nonequilibrium dynamics in isolated quantum systems, promoting intensive recent theoretical endeavors on this fundamental subject. Besides thermalization, many isolated quantum systems show intriguing behavior in relaxation processes, especially prethermalization. Prethermalization occurs when there is a clear separation of relevant time scales and has several different physical origins depending on individual systems. In this review, we overview theoretical approaches to the problems of thermalization and prethermalization.

Examining the potential contribution of social theory to developing and supporting Australian Indigenous-mainstream health service partnerships.

PubMed

Haynes, Emma; Taylor, Kate P; Durey, Angela; Bessarab, Dawn; Thompson, Sandra C

2014-09-20

The substantial gap in life expectancy between Indigenous and non-Indigenous Australians has been slow to improve, despite increased dedicated funding. Partnerships between Australian Indigenous and mainstream Western biomedical organisations are recognised as crucial to improved Indigenous health outcomes. However, these partnerships often experience challenges, particularly in the context of Australia's race and political relations. We examined the relevant literature in order to identify the potential role for social theory and theoretical models in developing and maintaining intercultural partnerships. Having identified relevant theoretical models, terms and possible key words, a range of databases were searched and relevant articles selected for inclusion. An integrative approach brought together theoretical models and practical considerations about working in partnership, to inform our analysis of the literature. Considering partnerships between Australian Indigenous and mainstream health organisations as 'bi-cultural' is simplistic: rather they are culturally diverse across social and professional levels. As such, partnerships between Australian Indigenous and mainstream health organisations may be better conceptualised as 'intercultural', operating across diverse and shifting cultural frames of reference. Theories identified by this review as useful to guide partnerships include power relations, reflexivity and dialogue, borders and strangeness and the intercultural or third space. This paper examines how these theoretical approaches can develop understanding and improve intercultural engagement between mainstream and Australian Indigenous partners in healthcare. Rather than viewing partnerships merely as arrangements between disembodied entities, sometimes contractual in nature, they are better seen as activities between people and organisations and essentially dependent on relationships, occurring in an intercultural space that is complex, dynamic and subject to changes in power relations. Theoretical models aiming to understand and improve partnerships indicate the complexity of building and maintaining such partnerships and stress the importance of understanding factors that can strengthen or derail their effectiveness. While the theories presented here are by no means exhaustive, they nonetheless provide a series of entry points through which to engage with the issue and expand the discourse. This approach allows the transformative nature of Australian Indigenous-mainstream 'culture' to be explored and understood in its lived expression; rather than relegated to prescriptive categories.

A Field Experimental Approach to the Study of Relevance Assessments in Relation to Document Searching. Final Report to the National Science Foundation. Volume I.

ERIC Educational Resources Information Center

Rees, Alan M; Schultz, Douglas G.

An empirical study of the nature and variability of the relevance judgment process was conducted from July 1, 1965 to September 30, 1967. Volume I of the final report presents a literature review and statement of the theoretical framework of the study, a discussion of the experimental design and a summary of data analyses. The study had two…

Intensity correlation imaging with sunlight-like source

NASA Astrophysics Data System (ADS)

Wang, Wentao; Tang, Zhiguo; Zheng, Huaibin; Chen, Hui; Yuan, Yuan; Liu, Jinbin; Liu, Yanyan; Xu, Zhuo

2018-05-01

We show a method of intensity correlation imaging of targets illuminated by a sunlight-like source both theoretically and experimentally. With a Faraday anomalous dispersion optical filter (FADOF), we have modulated the coherence time of a thermal source up to 0.167 ns. And we carried out measurements of temporal and spatial correlations, respectively, with an intensity interferometer setup. By skillfully using the even Fourier fitting on the very sparse sampling data, the images of targets are successfully reconstructed from the low signal-noise-ratio(SNR) interference pattern by applying an iterative phase retrieval algorithm. The resulting imaging quality is as well as the one obtained by the theoretical fitting. The realization of such a case will bring this technique closer to geostationary satellite imaging illuminated by sunlight.

Theory and Method in Cross-Cultural Psychology

ERIC Educational Resources Information Center

Malpass, Roy S.

1977-01-01

Cross cultural psychology is considered as a methodological strategy, as a means of evaluating hypotheses of unicultural origins with evidence of more panhuman relevance, and as a means of developing new theoretical psychological phenomena. (Author)

Toward Theory-Based Research in Political Communication.

ERIC Educational Resources Information Center

Simon, Adam F.; Iyengar, Shanto

1996-01-01

Praises the theoretical and methodological potential of the field of political communication. Calls for greater interaction and cross fertilization among the fields of political science, sociology, economics, and psychology. Briefly discusses relevant research methodologies. (MJP)

Etude theorique et experimentale de la correlation entre la resistance aux chocs thermiques et aux chocs mecaniques des materiaux refractaires utilises dans les fours de traitement de l'aluminium

NASA Astrophysics Data System (ADS)

Sebbani, Mohamed Jamal Eddine

2001-07-01

This work is a theoretical and experimental study of the correlation between the resistance to thermal shock and mechanical shock of refractory materials. The study of thermal shock showed that the Bahr and Hasselman approaches are alike and that they can be combined into a single, more general approach. This generalisation allowed the division of the theoretical models into two groups: the Hasselman model and the Harmuth model. However, neither of these approaches can predict the behaviour of all refractory materials submitted to thermal shock. Therefore, the generalisation of the Hasselman approach is more appropriate for more dense materials while the Hartmuth approach is more appropriate for less dense materials. The influence of porosity on the energy of rupture helped to explain the behaviour of the less dense material. The absence of generalisation in this case allows those parameters that could be correlated with thermal shock resistance to be dependent on the type of refractory. The study of mechanical shock provided a better understanding of this mechanism. The work performed showed, theoretically and experimentally, that the resistance of the refractory materials could be correlated with the parameter s20 Egwof n-22 . This new parameter helped to explain the statistical correlation between the resistance to mechanical impact and the soxRst parameter established in earlier work. The sintering influence, which makes the refractories more resistant to this type of demand, notably by reducing the "n" coefficient, was shown. This part of the study allowed the establishment of equivalence between thermal fatigue and fatigue by mechanical impact. An evaluation of the correlation between the two mechanisms demonstrated, theoretically and experimentally, that the mechanical and thermal demands could only be exceptionally correlated. In the case of thermal shock, which are imposed deformation demands, it is the shorter cracks which are the most dangerous. However, in the case of mechanical shock, which is constraint imposed, it is the longer cracks that are the most harmful. (Abstract shortened by UMI.)

BIOREL: the benchmark resource to estimate the relevance of the gene networks.

PubMed

Antonov, Alexey V; Mewes, Hans W

2006-02-06

The progress of high-throughput methodologies in functional genomics has lead to the development of statistical procedures to infer gene networks from various types of high-throughput data. However, due to the lack of common standards, the biological significance of the results of the different studies is hard to compare. To overcome this problem we propose a benchmark procedure and have developed a web resource (BIOREL), which is useful for estimating the biological relevance of any genetic network by integrating different sources of biological information. The associations of each gene from the network are classified as biologically relevant or not. The proportion of genes in the network classified as "relevant" is used as the overall network relevance score. Employing synthetic data we demonstrated that such a score ranks the networks fairly in respect to the relevance level. Using BIOREL as the benchmark resource we compared the quality of experimental and theoretically predicted protein interaction data.

Influences of Age and Emotion on Source Guessing: Are Older Adults More Likely to Show Fear-Relevant Illusory Correlations?

PubMed

Meyer, Miriam Magdalena; Buchner, Axel; Bell, Raoul

2016-09-01

The present study investigates age differences in the vulnerability to illusory correlations between fear-relevant stimuli and threatening information. Younger and older adults saw pictures of threatening snakes and nonthreatening fish, paired with threatening and nonthreatening context information ("poisonous" and "nonpoisonous") with a null contingency between animal type and poisonousness. In a source monitoring test, participants were required to remember whether an animal was associated with poisonousness or nonpoisonousness. Illusory correlations were implicitly measured via a multinomial model. One advantage of this approach is that memory and guessing processes can be assessed independently. An illusory correlation would be reflected in a higher probability of guessing that a snake rather than a fish was poisonous if the poisonousness of the animal was not remembered. Older adults showed evidence of illusory correlations in source guessing while younger adults did not; instead they showed evidence of probability matching. Moreover, snake fear was associated with increased vulnerability to illusory correlations in older adults. The findings confirm that older adults are more susceptible to fear-relevant illusory correlations than younger adults. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Task relevance modulates the behavioural and neural effects of sensory predictions

PubMed Central

Friston, Karl J.; Nobre, Anna C.

2017-01-01

The brain is thought to generate internal predictions to optimize behaviour. However, it is unclear whether predictions signalling is an automatic brain function or depends on task demands. Here, we manipulated the spatial/temporal predictability of visual targets, and the relevance of spatial/temporal information provided by auditory cues. We used magnetoencephalography (MEG) to measure participants’ brain activity during task performance. Task relevance modulated the influence of predictions on behaviour: spatial/temporal predictability improved spatial/temporal discrimination accuracy, but not vice versa. To explain these effects, we used behavioural responses to estimate subjective predictions under an ideal-observer model. Model-based time-series of predictions and prediction errors (PEs) were associated with dissociable neural responses: predictions correlated with cue-induced beta-band activity in auditory regions and alpha-band activity in visual regions, while stimulus-bound PEs correlated with gamma-band activity in posterior regions. Crucially, task relevance modulated these spectral correlates, suggesting that current goals influence PE and prediction signalling. PMID:29206225

Computing with Neural Synchrony

PubMed Central

Brette, Romain

2012-01-01

Neurons communicate primarily with spikes, but most theories of neural computation are based on firing rates. Yet, many experimental observations suggest that the temporal coordination of spikes plays a role in sensory processing. Among potential spike-based codes, synchrony appears as a good candidate because neural firing and plasticity are sensitive to fine input correlations. However, it is unclear what role synchrony may play in neural computation, and what functional advantage it may provide. With a theoretical approach, I show that the computational interest of neural synchrony appears when neurons have heterogeneous properties. In this context, the relationship between stimuli and neural synchrony is captured by the concept of synchrony receptive field, the set of stimuli which induce synchronous responses in a group of neurons. In a heterogeneous neural population, it appears that synchrony patterns represent structure or sensory invariants in stimuli, which can then be detected by postsynaptic neurons. The required neural circuitry can spontaneously emerge with spike-timing-dependent plasticity. Using examples in different sensory modalities, I show that this allows simple neural circuits to extract relevant information from realistic sensory stimuli, for example to identify a fluctuating odor in the presence of distractors. This theory of synchrony-based computation shows that relative spike timing may indeed have computational relevance, and suggests new types of neural network models for sensory processing with appealing computational properties. PMID:22719243

Relevance of the Nuclear Quantum Effects on the Proton/Deuteron Transmission through Hexagonal Boron Nitride and Graphene Monolayers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ekanayake, Niranji; Huang, Jingsong; Jakowski, Jacek

According to recent experiments, atomically thin hexagonal boron nitride and graphene are permeable to protons and deuterons (and not to other atomic species), and the experimental estimates of the activation energy are lower than the theoretical values by about 0.5 eV for the isolated proton-membrane transfer model. Our analysis of the electronic potential energy surfaces along the normal to the transmission direction, obtained using correlated electronic structure methods, suggests that the aqueous environment is essential to stabilize the proton { as opposed to the hydrogenatom { transmission. Therefore, the process is examined within a molecular model of H 2O {more » H(D) + { material { H 2O. Exact quantum-mechanical scattering calculations are performed to assess the relevance of the nuclear quantum eects, such as tunneling factors and the kinetic isotope eect (KIE). Deuteration is found to aect the thermal reaction rate constants (KIE of 3-4 for hexagonal boron nitride and 20-30 for the graphene) and to eectively lower the barriers to the proton transfer by 0.2 and 0.4 eV for the two membranes, respectively. This lowering eect is reduced for the deuteron by approximately a factor of three. A more comprehensive description of the proton transmission is likely to require an extended explicit aqueous environment.« less

Children with atopic dermatitis may have unacknowledged contact allergies contributing to their skin symptoms.

PubMed

Simonsen, A B; Johansen, J D; Deleuran, M; Mortz, C G; Skov, L; Sommerlund, M

2018-03-01

Whether children with atopic dermatitis have an altered risk of contact allergy than children without atopic dermatitis is frequently debated and studies have been conflicting. Theoretically, the impaired skin barrier in atopic dermatitis (AD) facilitates the penetration of potential allergens and several authors have highlighted the risk of underestimating and overlooking contact allergy in children with atopic dermatitis. To determine the prevalence of contact allergy in Danish children with atopic dermatitis and explore the problem of unacknowledged allergies maintaining or aggravating the skin symptoms. In a cross-sectional study, 100 children and adolescents aged 5-17 years with a diagnosis of atopic dermatitis were patch tested with a paediatric series of 31 allergens. Thirty per cent of the children had at least one positive patch test reaction, and 17% had at least one contact allergy that was relevant to the current skin symptoms. The risk of contact allergy was significantly correlated to the severity of atopic dermatitis. Metals and components of topical skincare products were the most frequent sensitizers. Patch testing is relevant as a screening tool in the management of children with atopic dermatitis as they may have unacknowledged contact allergies contributing to or maintaining their skin symptoms. Children with atopic dermatitis seem to be at greater risk of sensitization to certain allergens including metals and components of skincare products. © 2017 European Academy of Dermatology and Venereology.

Relevance of the Nuclear Quantum Effects on the Proton/Deuteron Transmission through Hexagonal Boron Nitride and Graphene Monolayers

DOE PAGES

Ekanayake, Niranji; Huang, Jingsong; Jakowski, Jacek; ...

2017-10-02

According to recent experiments, atomically thin hexagonal boron nitride and graphene are permeable to protons and deuterons (and not to other atomic species), and the experimental estimates of the activation energy are lower than the theoretical values by about 0.5 eV for the isolated proton-membrane transfer model. Our analysis of the electronic potential energy surfaces along the normal to the transmission direction, obtained using correlated electronic structure methods, suggests that the aqueous environment is essential to stabilize the proton { as opposed to the hydrogenatom { transmission. Therefore, the process is examined within a molecular model of H 2O {more » H(D) + { material { H 2O. Exact quantum-mechanical scattering calculations are performed to assess the relevance of the nuclear quantum eects, such as tunneling factors and the kinetic isotope eect (KIE). Deuteration is found to aect the thermal reaction rate constants (KIE of 3-4 for hexagonal boron nitride and 20-30 for the graphene) and to eectively lower the barriers to the proton transfer by 0.2 and 0.4 eV for the two membranes, respectively. This lowering eect is reduced for the deuteron by approximately a factor of three. A more comprehensive description of the proton transmission is likely to require an extended explicit aqueous environment.« less

"Time-dependent flow-networks"

NASA Astrophysics Data System (ADS)

Tupikina, Liubov; Molkentin, Nora; Lopez, Cristobal; Hernandez-Garcia, Emilio; Marwan, Norbert; Kurths, Jürgen

2015-04-01

Complex networks have been successfully applied to various systems such as society, technology, and recently climate. Links in a climate network are defined between two geographical locations if the correlation between the time series of some climate variable is higher than a threshold. Therefore, network links are considered to imply information or heat exchange. However, the relationship between the oceanic and atmospheric flows and the climate network's structure is still unclear. Recently, a theoretical approach verifying the correlation between ocean currents and surface air temperature networks has been introduced, where the Pearson correlation networks were constructed from advection-diffusion dynamics on an underlying flow. Since the continuous approach has its limitations, i.e. high computational complexity and fixed variety of the flows in the underlying system, we introduce a new, method of flow-networks for changing in time velocity fields including external forcing in the system, noise and temperature-decay. Method of the flow-network construction can be divided into several steps: first we obtain the linear recursive equation for the temperature time-series. Then we compute the correlation matrix for time-series averaging the tensor product over all realizations of the noise, which we interpret as a weighted adjacency matrix of the flow-network and analyze using network measures. We apply the method to different types of moving flows with geographical relevance such as meandering flow. Analyzing the flow-networks using network measures we find that our approach can highlight zones of high velocity by degree and transition zones by betweenness, while the combination of these network measures can uncover how the flow propagates within time. Flow-networks can be powerful tool to understand the connection between system's dynamics and network's topology analyzed using network measures in order to shed light on different climatic phenomena.

Equilibration in one-dimensional quantum hydrodynamic systems

NASA Astrophysics Data System (ADS)

Sotiriadis, Spyros

2017-10-01

We study quench dynamics and equilibration in one-dimensional quantum hydrodynamics, which provides effective descriptions of the density and velocity fields in gapless quantum gases. We show that the information content of the large time steady state is inherently connected to the presence of ballistically moving localised excitations. When such excitations are present, the system retains memory of initial correlations up to infinite times, thus evading decoherence. We demonstrate this connection in the context of the Luttinger model, the simplest quantum hydrodynamic model, and in the quantum KdV equation. In the standard Luttinger model, memory of all initial correlations is preserved throughout the time evolution up to infinitely large times, as a result of the purely ballistic dynamics. However nonlinear dispersion or interactions, when separately present, lead to spreading and delocalisation that suppress the above effect by eliminating the memory of non-Gaussian correlations. We show that, for any initial state that satisfies sufficient clustering of correlations, the steady state is Gaussian in terms of the bosonised or fermionised fields in the dispersive or interacting case respectively. On the other hand, when dispersion and interaction are simultaneously present, a semiclassical approximation suggests that localisation is restored as the two effects compensate each other and solitary waves are formed. Solitary waves, or simply solitons, are experimentally observed in quantum gases and theoretically predicted based on semiclassical approaches, but the question of their stability at the quantum level remains to a large extent an open problem. We give a general overview on the subject and discuss the relevance of our findings to general out of equilibrium problems. Dedicated to John Cardy on the occasion of his 70th birthday.

An alternative covariance estimator to investigate genetic heterogeneity in populations.

PubMed

Heslot, Nicolas; Jannink, Jean-Luc

2015-11-26

For genomic prediction and genome-wide association studies (GWAS) using mixed models, covariance between individuals is estimated using molecular markers. Based on the properties of mixed models, using available molecular data for prediction is optimal if this covariance is known. Under this assumption, adding individuals to the analysis should never be detrimental. However, some empirical studies showed that increasing training population size decreased prediction accuracy. Recently, results from theoretical models indicated that even if marker density is high and the genetic architecture of traits is controlled by many loci with small additive effects, the covariance between individuals, which depends on relationships at causal loci, is not always well estimated by the whole-genome kinship. We propose an alternative covariance estimator named K-kernel, to account for potential genetic heterogeneity between populations that is characterized by a lack of genetic correlation, and to limit the information flow between a priori unknown populations in a trait-specific manner. This is similar to a multi-trait model and parameters are estimated by REML and, in extreme cases, it can allow for an independent genetic architecture between populations. As such, K-kernel is useful to study the problem of the design of training populations. K-kernel was compared to other covariance estimators or kernels to examine its fit to the data, cross-validated accuracy and suitability for GWAS on several datasets. It provides a significantly better fit to the data than the genomic best linear unbiased prediction model and, in some cases it performs better than other kernels such as the Gaussian kernel, as shown by an empirical null distribution. In GWAS simulations, alternative kernels control type I errors as well as or better than the classical whole-genome kinship and increase statistical power. No or small gains were observed in cross-validated prediction accuracy. This alternative covariance estimator can be used to gain insight into trait-specific genetic heterogeneity by identifying relevant sub-populations that lack genetic correlation between them. Genetic correlation can be 0 between identified sub-populations by performing automatic selection of relevant sets of individuals to be included in the training population. It may also increase statistical power in GWAS.

DNA in the material world: electrical properties and nano-applications.

PubMed

Triberis, Georgios P; Dimakogianni, Margarita

2009-01-01

Contradictory experimental findings and theoretical interpretations have spurred intense debate over the electrical properties of the DNA double helix. In the present review article the various factors responsible for these divergences are discussed. The enlightenment of this issue could improve long range chemistry of oxidative DNA damage and repair processes, monitoring protein-DNA interactions and possible applications in nano-electronic circuit technology. The update experimental situation concerning measurements of the electrical conductivity is given. The character of the carriers responsible for the electrical conductivity measured in DNA is investigated. A theoretical model for the temperature dependence of the electrical conductivity of DNA is presented, based on microscopic models and percolation theoretical arguments. The theoretical results, excluding or including correlation effects, are applied to recent experimental findings for DNA, considering it as a one dimensional molecular wire. The results indicate that correlation effects are probably responsible for large hopping distances in DNA samples. Other theoretical conductivity models proposed for the interpretation of the responsible transport mechanism are also reviewed. Some of the most known and pioneering works on DNA's nano-applications, future developments and perspectives along with current technological limitations and patents are presented and discussed.

Flory-type theories of polymer chains under different external stimuli

NASA Astrophysics Data System (ADS)

Budkov, Yu A.; Kiselev, M. G.

2018-01-01

In this Review, we present a critical analysis of various applications of the Flory-type theories to a theoretical description of the conformational behavior of single polymer chains in dilute polymer solutions under a few external stimuli. Different theoretical models of flexible polymer chains in the supercritical fluid are discussed and analysed. Different points of view on the conformational behavior of the polymer chain near the liquid-gas transition critical point of the solvent are presented. A theoretical description of the co-solvent-induced coil-globule transitions within the implicit-solvent-explicit-co-solvent models is discussed. Several explicit-solvent-explicit-co-solvent theoretical models of the coil-to-globule-to-coil transition of the polymer chain in a mixture of good solvents (co-nonsolvency) are analysed and compared with each other. Finally, a new theoretical model of the conformational behavior of the dielectric polymer chain under the external constant electric field in the dilute polymer solution with an explicit account for the many-body dipole correlations is discussed. The polymer chain collapse induced by many-body dipole correlations of monomers in the context of statistical thermodynamics of dielectric polymers is analysed.

Theoretical analysis of the correlation observed in fatigue crack growth rate parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chay, S.C.; Liaw, P.K.

Fatigue crack growth rates have been found to follow the Paris-Erdogan rule, da/dN = C{sub o}({Delta}K){sup n}, for many steels, aluminum, nickel and copper alloys. The fatigue crack growth rate behavior in the Paris regime, thus, can be characterized by the parameters C{sub o} and n, which have been obtained for various materials. When n vs the logarithm of C{sub o} were plotted for various experimental results, a very definite linear relationship has been observed by many investigators, and questions have been raised as to the nature of this correlation. This paper presents a theoretical analysis that explains precisely whymore » such a linear correlation should exist between the two parameters, how strong the relationship should be, and how it can be predicted by analysis. This analysis proves that the source of such a correlation is of mathematical nature rather than physical.« less

Correlation estimation and performance optimization for distributed image compression

NASA Astrophysics Data System (ADS)

He, Zhihai; Cao, Lei; Cheng, Hui

2006-01-01

Correlation estimation plays a critical role in resource allocation and rate control for distributed data compression. A Wyner-Ziv encoder for distributed image compression is often considered as a lossy source encoder followed by a lossless Slepian-Wolf encoder. The source encoder consists of spatial transform, quantization, and bit plane extraction. In this work, we find that Gray code, which has been extensively used in digital modulation, is able to significantly improve the correlation between the source data and its side information. Theoretically, we analyze the behavior of Gray code within the context of distributed image compression. Using this theoretical model, we are able to efficiently allocate the bit budget and determine the code rate of the Slepian-Wolf encoder. Our experimental results demonstrate that the Gray code, coupled with accurate correlation estimation and rate control, significantly improves the picture quality, by up to 4 dB, over the existing methods for distributed image compression.

Quantum-Theoretical Methods and Studies Relating to Properties of Materials

DTIC Science & Technology

1989-12-19

particularly sensitive to the behavior of the electron distribution close to the nuclei, which contributes only to E(l). Although the above results were...other condensed phases. So it was a useful test case to test the behavior of the theoretical computations for the gas phase relative to that in the...increasingly complicated and time- comsuming electron-correlation approximations should assure a small error in the theoret- ically computed enthalpy for a

A bias correction for covariance estimators to improve inference with generalized estimating equations that use an unstructured correlation matrix.

PubMed

Westgate, Philip M

2013-07-20

Generalized estimating equations (GEEs) are routinely used for the marginal analysis of correlated data. The efficiency of GEE depends on how closely the working covariance structure resembles the true structure, and therefore accurate modeling of the working correlation of the data is important. A popular approach is the use of an unstructured working correlation matrix, as it is not as restrictive as simpler structures such as exchangeable and AR-1 and thus can theoretically improve efficiency. However, because of the potential for having to estimate a large number of correlation parameters, variances of regression parameter estimates can be larger than theoretically expected when utilizing the unstructured working correlation matrix. Therefore, standard error estimates can be negatively biased. To account for this additional finite-sample variability, we derive a bias correction that can be applied to typical estimators of the covariance matrix of parameter estimates. Via simulation and in application to a longitudinal study, we show that our proposed correction improves standard error estimation and statistical inference. Copyright © 2012 John Wiley & Sons, Ltd.

The impact of electrostatic correlations on Dielectrophoresis of Non-conducting Particles

NASA Astrophysics Data System (ADS)

Alidoosti, Elaheh; Zhao, Hui

2017-11-01

The dipole moment of a charged, dielectric, spherical particle under the influence of a uniform alternating electric field is computed theoretically and numerically by solving the modified continuum Poisson-Nernst-Planck (PNP) equations accounting for ion-ion electrostatic correlations that is important at concentrated electrolytes (Phys. Rev. Lett. 106, 2011). The dependence on the frequency, zeta potential, electrostatic correlation lengths, and double layer thickness is thoroughly investigated. In the limit of thin double layers, we carry out asymptotic analysis to develop simple models which are in good agreement with the modified PNP model. Our results suggest that the electrostatic correlations have a complicated impact on the dipole moment. As the electrostatic correlations length increases, the dipole moment decreases, initially, reach a minimum, and then increases since the surface conduction first decreases and then increases due to the ion-ion correlations. The modified PNP model can improve the theoretical predictions particularly at low frequencies where the simple model can't qualitatively predict the dipole moment. This work was supported, in part, by NIH R15GM116039.

Electromagnetic Compatibility Testing Studies

NASA Technical Reports Server (NTRS)

Trost, Thomas F.; Mitra, Atindra K.

1996-01-01

This report discusses the results on analytical models and measurement and simulation of statistical properties from a study of microwave reverberation (mode-stirred) chambers performed at Texas Tech University. Two analytical models of power transfer vs. frequency in a chamber, one for antenna-to-antenna transfer and the other for antenna to D-dot sensor, were experimentally validated in our chamber. Two examples are presented of the measurement and calculation of chamber Q, one for each of the models. Measurements of EM power density validate a theoretical probability distribution on and away from the chamber walls and also yield a distribution with larger standard deviation at frequencies below the range of validity of the theory. Measurements of EM power density at pairs of points which validate a theoretical spatial correlation function on the chamber walls and also yield a correlation function with larger correlation length, R(sub corr), at frequencies below the range of validity of the theory. A numerical simulation, employing a rectangular cavity with a moving wall shows agreement with the measurements. The determination that the lowest frequency at which the theoretical spatial correlation function is valid in our chamber is considerably higher than the lowest frequency recommended by current guidelines for utilizing reverberation chambers in EMC testing. Two suggestions have been made for future studies related to EMC testing.

Vista goes online: Decision-analytic systems for real-time decision-making in mission control

NASA Technical Reports Server (NTRS)

Barry, Matthew; Horvitz, Eric; Ruokangas, Corinne; Srinivas, Sampath

1994-01-01

The Vista project has centered on the use of decision-theoretic approaches for managing the display of critical information relevant to real-time operations decisions. The Vista-I project originally developed a prototype of these approaches for managing flight control displays in the Space Shuttle Mission Control Center (MCC). The follow-on Vista-II project integrated these approaches in a workstation program which currently is being certified for use in the MCC. To our knowledge, this will be the first application of automated decision-theoretic reasoning techniques for real-time spacecraft operations. We shall describe the development and capabilities of the Vista-II system, and provide an overview of the use of decision-theoretic reasoning techniques to the problems of managing the complexity of flight controller displays. We discuss the relevance of the Vista techniques within the MCC decision-making environment, focusing on the problems of detecting and diagnosing spacecraft electromechanical subsystems component failures with limited information, and the problem of determining what control actions should be taken in high-stakes, time-critical situations in response to a diagnosis performed under uncertainty. Finally, we shall outline our current research directions for follow-on projects.

Shifting attention from objective risk factors to patients' self-assessed health resources: a clinical model for general practice.

PubMed

Hollnagel, H; Malterud, K

1995-12-01

The study was designed to present and apply theoretical and empirical knowledge for the construction of a clinical model intended to shift the attention of the general practitioner from objective risk factors to self-assessed health resources in male and female patients. Review, discussion and analysis of selected theoretical models about personal health resources involving assessing existing theories according to their emphasis concerning self-assessed vs. doctor-assessed health resources, specific health resources vs. life and coping in general, abstract vs. clinically applicable theory, gender perspective explicitly included or not. Relevant theoretical models on health and coping (salutogenesis, coping and social support, control/demand, locus of control, health belief model, quality of life), and the perspective of the underprivileged Other (critical theory, feminist standpoint theory, the patient-centred clinical method) were presented and assessed. Components from Antonovsky's salutogenetic perspective and McWhinney's patient-centred clinical method, supported by gender perspectives, were integrated to a clinical model which is presented. General practitioners are recommended to shift their attention from objective risk factors to self-assessed health resources by means of the clinical model. The relevance and feasibility of the model should be explored in empirical research.

A framework for biodynamic feedthrough analysis--part I: theoretical foundations.

PubMed

Venrooij, Joost; van Paassen, Marinus M; Mulder, Mark; Abbink, David A; Mulder, Max; van der Helm, Frans C T; Bulthoff, Heinrich H

2014-09-01

Biodynamic feedthrough (BDFT) is a complex phenomenon, which has been studied for several decades. However, there is little consensus on how to approach the BDFT problem in terms of definitions, nomenclature, and mathematical descriptions. In this paper, a framework for biodynamic feedthrough analysis is presented. The goal of this framework is two-fold. First, it provides some common ground between the seemingly large range of different approaches existing in the BDFT literature. Second, the framework itself allows for gaining new insights into BDFT phenomena. It will be shown how relevant signals can be obtained from measurement, how different BDFT dynamics can be derived from them, and how these different dynamics are related. Using the framework, BDFT can be dissected into several dynamical relationships, each relevant in understanding BDFT phenomena in more detail. The presentation of the BDFT framework is divided into two parts. This paper, Part I, addresses the theoretical foundations of the framework. Part II, which is also published in this issue, addresses the validation of the framework. The work is presented in two separate papers to allow for a detailed discussion of both the framework's theoretical background and its validation.

Graph-theoretic strengths of contextuality

NASA Astrophysics Data System (ADS)

de Silva, Nadish

2017-03-01

Cabello-Severini-Winter and Abramsky-Hardy (building on the framework of Abramsky-Brandenburger) both provide classes of Bell and contextuality inequalities for very general experimental scenarios using vastly different mathematical techniques. We review both approaches, carefully detail the links between them, and give simple, graph-theoretic methods for finding inequality-free proofs of nonlocality and contextuality and for finding states exhibiting strong nonlocality and/or contextuality. Finally, we apply these methods to concrete examples in stabilizer quantum mechanics relevant to understanding contextuality as a resource in quantum computation.

Black hole state counting in loop quantum gravity: a number-theoretical approach.

PubMed

Agulló, Iván; Barbero G, J Fernando; Díaz-Polo, Jacobo; Fernández-Borja, Enrique; Villaseñor, Eduardo J S

2008-05-30

We give an efficient method, combining number-theoretic and combinatorial ideas, to exactly compute black hole entropy in the framework of loop quantum gravity. Along the way we provide a complete characterization of the relevant sector of the spectrum of the area operator, including degeneracies, and explicitly determine the number of solutions to the projection constraint. We use a computer implementation of the proposed algorithm to confirm and extend previous results on the detailed structure of the black hole degeneracy spectrum.

Envelopes in eclipsing binary stars

NASA Technical Reports Server (NTRS)

Huang, S.

1972-01-01

Theoretical research on eclipsing binaries is presented. The specific areas of investigation are the following: (1) the relevance of envelopes to the study of the light curves of eclipsing binaries, (2) the disk envelope, and (3) the spherical envelope.

Slower reacquisition after partial extinction in human contingency learning.

PubMed

Morís, Joaquín; Barberia, Itxaso; Vadillo, Miguel A; Andrades, Ainhoa; López, Francisco J

2017-01-01

Extinction is a very relevant learning phenomenon from a theoretical and applied point of view. One of its most relevant features is that relapse phenomena often take place once the extinction training has been completed. Accordingly, as extinction-based therapies constitute the most widespread empirically validated treatment of anxiety disorders, one of their most important limitations is this potential relapse. We provide the first demonstration of relapse reduction in human contingency learning using mild aversive stimuli. This effect was found after partial extinction (i.e., reinforced trials were occasionally experienced during extinction, Experiment 1) and progressive extinction treatments (Experiment 3), and it was not only because of differences in uncertainty levels between the partial and a standard extinction group (Experiment 2). The theoretical explanation of these results, the potential uses of this strategy in applied situations, and its current limitations are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Affective picture processing: An integrative review of ERP findings

PubMed Central

Olofsson, Jonas K.; Nordin, Steven; Sequeira, Henrique; Polich, John

2008-01-01

The review summarizes and integrates findings from 40 years of event-related potential (ERP) studies using pictures that differ in valence (unpleasant-to-pleasant) and arousal (low-to-high) and that are used to elicit emotional processing. Affective stimulus factors primarily modulate ERP component amplitude, with little change in peak latency observed. Arousal effects are consistently obtained, and generally occur at longer latencies. Valence effects are inconsistently reported at several latency ranges, including very early components. Some affective ERP modulations vary with recording methodology, stimulus factors, as well as task-relevance and emotional state. Affective ERPs have been linked theoretically to attention orientation for unpleasant pictures at earlier components (< 300 ms). Enhanced stimulus processing has been associated with memory encoding for arousing pictures of assumed intrinsic motivational relevance, with task-induced differences contributing to emotional reactivity at later components (> 300 ms). Theoretical issues, stimulus factors, task demands, and individual differences are discussed. PMID:18164800

Investigation on coupling error characteristics in angular rate matching based ship deformation measurement approach

NASA Astrophysics Data System (ADS)

Yang, Shuai; Wu, Wei; Wang, Xingshu; Xu, Zhiguang

2018-01-01

The coupling error in the measurement of ship hull deformation can significantly influence the attitude accuracy of the shipborne weapons and equipments. It is therefore important to study the characteristics of the coupling error. In this paper, an comprehensive investigation on the coupling error is reported, which has a potential of deducting the coupling error in the future. Firstly, the causes and characteristics of the coupling error are analyzed theoretically based on the basic theory of measuring ship deformation. Then, simulations are conducted for verifying the correctness of the theoretical analysis. Simulation results show that the cross-correlation between dynamic flexure and ship angular motion leads to the coupling error in measuring ship deformation, and coupling error increases with the correlation value between them. All the simulation results coincide with the theoretical analysis.

Electronic properties of CdWO{sub 4}: Use of hybrid exchange and correlation functionals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meena, B. S., E-mail: bsmphysics@gmail.com; Mund, H. S.; Ahuja, B. L.

Energy bands, density of states (DOS), Mulliken population (MP) and electron momentum densities (EMDs) of CdWO{sub 4} are presented using hybrid exchange and correlation functionals namely B3LYP, B3PW and PBE0. To validate the present hybrid potentials, theoretical EMDs have been compared with the experimental Compton profile. It is found that LCAO-B3LYP based Compton profile gives a better agreement with experiment than other theoretical profiles. The energy bands and DOS show a wide band gap semiconducting nature of CdWO{sub 4}. The theoretical band gap obtained using B3LYP scheme reconciles well with the available experimental data. In addition, we have also presentedmore » the anisotropies in EMDs along [100], [110] and [001] directions and the bonding effects using the MP data.« less

Utility of pedometers for assessing physical activity: construct validity.

PubMed

Tudor-Locke, Catrine; Williams, Joel E; Reis, Jared P; Pluto, Delores

2004-01-01

Valid assessment of physical activity is necessary to fully understand this important health-related behaviour for research, surveillance, intervention and evaluation purposes. This article is the second in a companion set exploring the validity of pedometer-assessed physical activity. The previous article published in Sports Medicine dealt with convergent validity (i.e. the extent to which an instrument's output is associated with that of other instruments intended to measure the same exposure of interest). The present focus is on construct validity. Construct validity is the extent to which the measurement corresponds with other measures of theoretically-related parameters. Construct validity is typically evaluated by correlational analysis, that is, the magnitude of concordance between two measures (e.g. pedometer-determined steps/day and a theoretically-related parameter such as age, anthropometric measures and fitness). A systematic literature review produced 29 articles published since > or =1980 directly relevant to construct validity of pedometers in relation to age, anthropometric measures and fitness. Reported correlations were combined and a median r-value was computed. Overall, there was a weak inverse relationship (median r = -0.21) between age and pedometer-determined physical activity. A weak inverse relationship was also apparent with both body mass index and percentage overweight (median r = -0.27 and r = -0.22, respectively). Positive relationships regarding indicators of fitness ranged from weak to moderate depending on the fitness measure utilised: 6-minute walk test (median r = 0.69), timed treadmill test (median r = 0.41) and estimated maximum oxygen uptake (median r = 0.22). Studies are warranted to assess the relationship of pedometer-determined physical activity with other important health-related outcomes including blood pressure and physiological parameters such as blood glucose and lipid profiles. The aggregated evidence of convergent validity (presented in the previous companion article) and construct validity herein provides support for considering simple and inexpensive pedometers in both research and practice.

A German e-learning-training in the context of early preventive intervention and child protection: preliminary findings of a pre-post evaluation.

PubMed

Bressem, Kristina; Ziegenhain, Ute; Doelitzsch, Claudia; Hofer, Alexandra; Besier, Tanja; Fegert, Joerg M; Kuenster, Anne K

2016-01-01

In recent years, a number of government-sponsored initiatives have been implemented in Germany that are focused on early preventive intervention in child protection. In response to the need for interdisciplinary training in this area, the internet-based e-learning program "Early Preventive Intervention and Child Protection" was developed for professionals in the child welfare and health care systems working with families with infants and toddlers. The program is currently undergoing evaluation for effectiveness and user satisfaction. In a pre-post design, users are requested to complete questionnaires that assess three measures of expertise: theoretical knowledge of relevant fields, the ability to correctly identify subtle signals of infant communication, and the ability to assess maternal sensitivity. This article presents the contents of the program and the pre-training results (N = 1.294 participants). Descriptive analyses as well as Pearson correlations and Bonferroni corrections of error were conducted using the statistical program SPSS v. 21.0. The findings show that a wide range of professionals are making use of the program, and that their existing theoretical knowledge about early preventive intervention, as well as their ability to identify subtle signals of infant communication, is relatively good. However, their ability to assess maternal sensitivity, which is considered a crucial indicator for the risk of child abuse, was low. The outcome of the pre-training results indicates that professionals working in the area of child protection need to develop more capability in recognizing maternal sensitivity, in order to ensure early detection of families who are at risk and thus in need of support. Finally, the number of years of professional experience did not correlate with the scores on any of the three measures, which emphasizes the importance of providing interdisciplinary training in this area for all those working in child and family services, regardless of background.

A cross-correlation study of the Fermi-LAT γ-ray diffuse extragalactic signal

DOE PAGES

Xia, Jun -Qing; Cuoco, Alessandro; Branchini, Enzo; ...

2011-09-12

In this work, starting from 21 months of data from the Fermi Large Area Telescope (LAT), we derive maps of the residual isotropic γ-ray emission, a relevant fraction of which is expected to be contributed by the extragalactic diffuse γ-ray background (EGB). We search for the auto-correlation signals in the above γ-ray maps and for the cross-correlation signal with the angular distribution of different classes of objects that trace the large-scale structure of the Universe. We compute the angular two-point auto-correlation function of the residual Fermi-LAT maps at energies E > 1 GeV, E > 3 GeV and E >more » 30 GeV well above the Galactic plane and find no significant correlation signal. This is, indeed, what is expected if the EGB were contributed by BL Lacertae (BLLacs), Flat Spectrum Radio Quasars (FSRQs) or star-forming galaxies, since, in this case, the predicted signal is very weak. Then, we search for the Integrated Sachs–Wolfe (ISW) signature by cross-correlating the Fermi-LAT maps with the 7-year Wilkinson Microwave Anisotropy Probe ( WMAP7) cosmic microwave background map. We find a cross-correlation consistent with zero, even though the expected signal is larger than that of the EGB auto-correlation. Lastly, in an attempt to constrain the nature of the γ-ray background, we cross-correlate the Fermi-LAT maps with the angular distributions of objects that may contribute to the EGB: quasi-stellar objects (QSOs) in the Sloan Digital Sky Survey Data Release 6 (SDSS-DR6) catalogue, NRAO VLA Sky Survey (NVSS) galaxies, Two Micron All Sky Survey (2MASS) galaxies and Luminous Red Galaxies (LRGs) in the SDSS catalogue. The cross-correlation is always consistent with zero, in agreement with theoretical expectations, but we find (with low statistical significance) some interesting features that may indicate that some specific classes of objects contribute to the EGB. A χ 2 analysis confirms that the correlation properties of the 21-month data do not provide strong constraints of the EGB origin. However, the results suggest that the situation will significantly improve with the 5- and 10-yr Fermi-LAT data. In future, the EGB analysis will then allow placing significant constraints on the nature of the EGB and might provide, in addition, a detection of the ISW signal.« less

Theoretical and experimental study of a fiber optic microphone

NASA Technical Reports Server (NTRS)

Hu, Andong; Cuomo, Frank W.; Zuckerwar, Allan J.

1992-01-01

Modifications to condenser microphone theory yield new expressions for the membrane deflections at its center, which provide the basic theory for the fiber optic microphone. The theoretical analysis for the membrane amplitude and the phase response of the fiber optic microphone is given in detail in terms of its basic geometrical quantities. A relevant extension to the original concepts of the optical microphone includes the addition of a backplate with holes similar in design to present condenser microphone technology. This approach generates improved damping characteristics and extended frequency response that were not previously considered. The construction and testing of the improved optical fiber microphone provide experimental data that are in good agreement with the theoretical analysis.

Conceptual models for cumulative risk assessment.

PubMed

Linder, Stephen H; Sexton, Ken

2011-12-01

In the absence of scientific consensus on an appropriate theoretical framework, cumulative risk assessment and related research have relied on speculative conceptual models. We argue for the importance of theoretical backing for such models and discuss 3 relevant theoretical frameworks, each supporting a distinctive "family" of models. Social determinant models postulate that unequal health outcomes are caused by structural inequalities; health disparity models envision social and contextual factors acting through individual behaviors and biological mechanisms; and multiple stressor models incorporate environmental agents, emphasizing the intermediary role of these and other stressors. The conclusion is that more careful reliance on established frameworks will lead directly to improvements in characterizing cumulative risk burdens and accounting for disproportionate adverse health effects.

Conceptual Models for Cumulative Risk Assessment

PubMed Central

Sexton, Ken

2011-01-01

In the absence of scientific consensus on an appropriate theoretical framework, cumulative risk assessment and related research have relied on speculative conceptual models. We argue for the importance of theoretical backing for such models and discuss 3 relevant theoretical frameworks, each supporting a distinctive “family” of models. Social determinant models postulate that unequal health outcomes are caused by structural inequalities; health disparity models envision social and contextual factors acting through individual behaviors and biological mechanisms; and multiple stressor models incorporate environmental agents, emphasizing the intermediary role of these and other stressors. The conclusion is that more careful reliance on established frameworks will lead directly to improvements in characterizing cumulative risk burdens and accounting for disproportionate adverse health effects. PMID:22021317

Conceptualizing, Designing, and Investigating Locative Media Use in Urban Space

NASA Astrophysics Data System (ADS)

Diamantaki, Katerina; Rizopoulos, Charalampos; Charitos, Dimitris; Kaimakamis, Nikos

This chapter investigates the social implications of locative media (LM) use and attempts to outline a theoretical framework that may support the design and implementation of location-based applications. Furthermore, it stresses the significance of physical space and location awareness as important factors that influence both human-computer interaction and computer-mediated communication. The chapter documents part of the theoretical aspect of the research undertaken as part of LOcation-based Communication Urban NETwork (LOCUNET), a project that aims to investigate the way users interact with one another (human-computer-human interaction aspect) and with the location-based system itself (human-computer interaction aspect). A number of relevant theoretical approaches are discussed in an attempt to provide a holistic theoretical background for LM use. Additionally, the actual implementation of the LOCUNET system is described and some of the findings are discussed.

Thought for application and application with thought: issues in theoretical thinking and practical wisdom.

PubMed

Jenkins, Sandra K; Thomas, Mary Beth

2005-01-01

Both theoretical thinking and practical wisdom are used by health professionals in their clinical practice. Lately, discussion has centered on the abstract phrase "theory-practice gap." The health profession is not the only discipline that seeks unity in theory and practice issues. Education is also building bridges in this arena. One reoccurring myth is the notion that theory and practice are separate; as a result, this gives a mistaken impression that theory serves no purpose in practice. Discussion of the issues in this paper includes definitions of theoretical thinking and practical wisdom, theoretical and practical knowledge development, and relevance to health professional's education, practice and science. These issues must be communicated to practitioners, educators and theorists. A collective definition to begin communication is proposed and suggestions are offered for addressing key issues.

Fear-relevant illusory correlations in different fears and anxiety disorders: A review of the literature.

PubMed

Wiemer, Julian; Pauli, Paul

2016-08-01

Fearful individuals often overestimate the relationship between fear-relevant stimuli and aversive consequences. Such fear-relevant illusory correlations (ICs) might be involved in the maintenance of anxiety disorders. In this literature review, we found clear evidence that ICs are present and enhanced in fear of animals. We also revealed some evidence for ICs related to fear of flying, social anxiety, contamination fear, panic disorder, and post-traumatic stress disorder, but with considerably less clarity. Fear-relevant ICs seem to be best explained by both a priori expectancies and biased encoding of the experienced associations. Studies to date suggest that one important biased encoding process is the enhanced aversiveness/salience of fear-relevant outcomes. Future studies may improve insight by developing more reliable IC measures and testing the effect of encoding processes on treatment outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Interrogative suggestibility: its relationship with assertiveness, social-evaluative anxiety, state anxiety and method of coping.

PubMed

Gudjonsson, G H

1988-05-01

This paper attempts to investigate empirically in 30 subjects some of the theoretical components related to individual differences that are thought by Gudjonsson & Clark (1986) to mediate interrogative suggestibility as measured by the Gudjonsson Suggestibility Scale (GSS; Gudjonsson, 1984a). The variables studied were: assertiveness, social-evaluative anxiety, state anxiety and the coping methods subjects are able to generate and implement during interrogation. Low assertiveness and high evaluative anxiety were found to correlate moderately with suggestibility, but no significant correlations emerged for 'social avoidance and distress'. State anxiety correlated significantly with suggestibility, particularly after negative feedback had been administered. Coping methods (active-cognitive/behavioural vs. avoidance) significantly predicted suggestibility scores. The findings give strong support to the theoretical model of Gudjonsson & Clark.

A Laboratory-Based Test of the Relation between Adolescent Alcohol Use and Panic-Relevant Responding

PubMed Central

Blumenthal, Heidemarie; Cloutier, Renee M.; Zamboanga, Byron L.; Bunaciu, Liviu; Knapp, Ashley A.

2015-01-01

A burgeoning literature supports a link between alcohol use and panic-spectrum problems (e.g., panic attacks, disorder) among adolescents, but the direction of influence has yet to be properly examined. From a theoretical perspective, panic-spectrum problems may increase risk for problematic drinking via affect regulation efforts (e.g., self-medication), and problematic consumption also may increase or initiate panic-relevant responding (e.g., learning or kindling models). The objective of the current investigation was to examine the role of prior alcohol use in predicting panic-relevant responding, as well as panic symptom history in predicting the desire to consume alcohol, in the context of either a voluntary hyperventilation or a low-arousal task. Participants were community-recruited adolescents aged 12-17 years (n = 92, Mage = 15.42, SD = 1.51; 39.1% girls). Results indicated that prior alcohol use predicted panic-relevant responding among those undergoing the hyperventilation task (but not the low-arousal task), and that this finding was robust to the inclusion of theoretically-relevant covariates (i.e. age, sex, negative affectivity). However, panic symptom history did not predict the desire to consume alcohol as a function of either the hyperventilation or low-arousal condition. This work sheds further light on the nature of the relation between panic-spectrum problems and problematic alcohol use in adolescence. Specifically, the current findings suggest that frequent alcohol use may increase panic vulnerability among adolescents, whereas acute panic symptoms may not elicit the immediate (self-reported) desire to drink. PMID:26053320

Alcohol Use History and Panic-Relevant Responding among Adolescents: A Test using a Voluntary Hyperventilation Challenge

PubMed Central

Blumenthal, Heidemarie; Leen-Feldner, Ellen W.; Knapp, Ashley A.; Bunaciu, Liviu; Zamboanga, Byron L.

2012-01-01

Given the onset of alcohol use, neurological sensitivity, and enhanced panic-relevant vulnerability, adolescence is a key period in which to study the documented linkage between alcohol and panic-related problems. The current study was designed to build upon and uniquely extend extant work via (1) utilization of well-established experimental psychopathology techniques, and (2) evaluation of unique associations between alcohol use and panic symptoms after controlling for theoretically-relevant behavioral, environmental, and individual difference variables (i.e., age, gender, negative affectivity, anxiety sensitivity, child and parent tobacco use, and parental panic disorder). Participants were 111 community-recruited adolescents ages 12–17 years (M = 15.76 years; n = 50 girls). Youth completed a battery of well-established questionnaires and a voluntary hyperventilation challenge, and parents present at the laboratory completed a structured clinical interview. Adolescent alcohol use was categorized as Non-Users, Experimenters, or Users. Panic symptoms were indexed via retrospective self-report and adolescents’ response to a biological challenge procedure (i.e., voluntary hyperventilation). After controlling for theoretically-relevant covariates, Users evidenced elevated panic-relevant symptoms and responding compared to Non-Users; Experimenters did not differ from Non-Users. Findings suggest alcohol use history is uniquely associated with panic symptomatology among youth, including “real-time” reactivity elicited by a laboratory challenge. While there is significant work yet to be done, these data advance extant work and lay the groundwork for the types of sophisticated designs that will be needed to answer the most pressing and complex questions regarding the link between alcohol use and panic symptoms among adolescents. PMID:22369219

Remembrance of Things Past

ERIC Educational Resources Information Center

Heckel, Robert V.; Heckel, Nancy W.

1976-01-01

An attempt was undertaken to demonstrate a relationship between earliest memories and a perception of significant future events. Relevance here was in the role that early memories play in the theoretical bases and treatment processes of all dynamically oriented therapies. (Author/RK)

Non-Normality and Testing that a Correlation Equals Zero

ERIC Educational Resources Information Center

Levy, Kenneth J.

1977-01-01

The importance of the assumption of normality for testing that a bivariate normal correlation equals zero is examined. Both empirical and theoretical evidence suggest that such tests are robust with respect to violation of the normality assumption. (Author/JKS)

Health-relevant personality is associated with sensitivity to sound (hyperacusis).

PubMed

Villaume, Karin; Hasson, Dan

2017-04-01

Hyperacusis, over-sensitivity to sounds, causes distress and disability and the etiology is not fully understood. The study aims to explore possible associations between health-relevant personality traits and hyperacusis. Hyperacusis was assessed using the Hyperacusis Questionnaire (HQ), and clinical uncomfortable loudness levels (ULL). Personality was measured with the Health-relevant Personality (HP5i) Inventory. The study sample was 348 (140 men and 208 women; age 23-71 years). Moderate correlations were found between the personality trait negative affectivity (NA; a facet of neuroticism) and dimensions of the HQ and weak correlations were found with the ULLs. Hedonic capacity (a facet of extraversion) was significantly correlated with the HQ but not with the ULLs. Impulsivity (a facet of conscientiousness) was correlated with the HQ and the ULLs. A significant difference in mean values was found in all hyperacusis measures and different levels of NA - those with higher levels displayed more severe signs of hyperacusis. A multiple logistic regression analysis showed that higher levels of NA increases the odds of having hyperacusis on average 4.6 times for men and 2.4 times for women. These findings imply that health-relevant personality traits should be considered in the diagnosis and treatment of hyperacusis. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

The rank correlated FSK model for prediction of gas radiation in non-uniform media, and its relationship to the rank correlated SLW model

NASA Astrophysics Data System (ADS)

Solovjov, Vladimir P.; Webb, Brent W.; Andre, Frederic

2018-07-01

Following previous theoretical development based on the assumption of a rank correlated spectrum, the Rank Correlated Full Spectrum k-distribution (RC-FSK) method is proposed. The method proves advantageous in modeling radiation transfer in high temperature gases in non-uniform media in two important ways. First, and perhaps most importantly, the method requires no specification of a reference gas thermodynamic state. Second, the spectral construction of the RC-FSK model is simpler than original correlated FSK models, requiring only two cumulative k-distributions. Further, although not exhaustive, example problems presented here suggest that the method may also yield improved accuracy relative to prior methods, and may exhibit less sensitivity to the blackbody source temperature used in the model predictions. This paper outlines the theoretical development of the RC-FSK method, comparing the spectral construction with prior correlated spectrum FSK method formulations. Further the RC-FSK model's relationship to the Rank Correlated Spectral Line Weighted-sum-of-gray-gases (RC-SLW) model is defined. The work presents predictions using the Rank Correlated FSK method and previous FSK methods in three different example problems. Line-by-line benchmark predictions are used to assess the accuracy.

Humans display a reduced set of consistent behavioral phenotypes in dyadic games.

PubMed

Poncela-Casasnovas, Julia; Gutiérrez-Roig, Mario; Gracia-Lázaro, Carlos; Vicens, Julian; Gómez-Gardeñes, Jesús; Perelló, Josep; Moreno, Yamir; Duch, Jordi; Sánchez, Angel

2016-08-01

Socially relevant situations that involve strategic interactions are widespread among animals and humans alike. To study these situations, theoretical and experimental research has adopted a game theoretical perspective, generating valuable insights about human behavior. However, most of the results reported so far have been obtained from a population perspective and considered one specific conflicting situation at a time. This makes it difficult to extract conclusions about the consistency of individuals' behavior when facing different situations and to define a comprehensive classification of the strategies underlying the observed behaviors. We present the results of a lab-in-the-field experiment in which subjects face four different dyadic games, with the aim of establishing general behavioral rules dictating individuals' actions. By analyzing our data with an unsupervised clustering algorithm, we find that all the subjects conform, with a large degree of consistency, to a limited number of behavioral phenotypes (envious, optimist, pessimist, and trustful), with only a small fraction of undefined subjects. We also discuss the possible connections to existing interpretations based on a priori theoretical approaches. Our findings provide a relevant contribution to the experimental and theoretical efforts toward the identification of basic behavioral phenotypes in a wider set of contexts without aprioristic assumptions regarding the rules or strategies behind actions. From this perspective, our work contributes to a fact-based approach to the study of human behavior in strategic situations, which could be applied to simulating societies, policy-making scenario building, and even a variety of business applications.

Cognitive performance in mid-stage Parkinson's disease: functional connectivity under chronic antiparkinson treatment.

PubMed

Vancea, Roxana; Simonyan, Kristina; Petracca, Maria; Brys, Miroslaw; Di Rocco, Alessandro; Ghilardi, Maria Felice; Inglese, Matilde

2017-09-23

Cognitive impairment in Parkinson's disease (PD) is related to the reorganization of brain topology. Although drug challenge studies have proven how levodopa treatment can modulate functional connectivity in brain circuits, the role of chronic dopaminergic therapy on cognitive status and functional connectivity has never been investigated. We sought to characterize brain functional topology in mid-stage PD patients under chronic antiparkinson treatment and explore the presence of correlation between reorganization of brain architecture and specific cognitive deficits. We explored networks topology and functional connectivity in 16 patients with PD and 16 matched controls through a graph theoretical analysis of resting state-functional MRI data, and evaluated the relationships between network metrics and cognitive performance. PD patients showed a preserved small-world network topology but a lower clustering coefficient in comparison with healthy controls. Locally, PD patients showed lower degree of connectivity and local efficiency in many hubs corresponding to functionally relevant areas. Four disconnected subnetworks were also identified in regions responsible for executive control, sensory-motor control and planning, motor coordination and visual elaboration. Executive functions and information processing speed were directly correlated with degree of connectivity and local efficiency in frontal, parietal and occipital areas. While functional reorganization appears in both motor and cognitive areas, the clinical expression of network imbalance seems to be partially compensated by the chronic levodopa treatment with regards to the motor but not to the cognitive performance. In a context of reduced network segregation, the presence of higher local efficiency in hubs regions correlates with a better cognitive performance.

Field signatures of non-Fickian transport processes: transit time distributions, spatial correlations, reversibility and hydrogeophysical imaging

NASA Astrophysics Data System (ADS)

Le Borgne, T.; Kang, P. K.; Guihéneuf, N.; Shakas, A.; Bour, O.; Linde, N.; Dentz, M.

2015-12-01

Non-Fickian transport phenomena are observed in a wide range of scales across hydrological systems. They are generally manifested by a broad range of transit time distributions, as measured for instance in tracer breakthrough curves. However, similar transit time distributions may be caused by different origins, including broad velocity distributions, flow channeling or diffusive mass transfer [1,2]. The identification of these processes is critical for defining relevant transport models. How can we distinguish the different origins of non-Fickian transport in the field? In this presentation, we will review recent experimental developments to decipher the different causes of anomalous transport, based on tracer tests performed at different scales in cross borehole and push pull conditions, and time lapse hydrogeophysical imaging of tracer motion [3,4]. References:[1] de Anna-, P., T. Le Borgne, M. Dentz, A. M. Tartakovsky, D. Bolster, P. Davy (2013) Flow Intermittency, Dispersion and Correlated Continuous Time Random Walks in Porous Media, Phys. Rev. Lett., 110, 184502 [2] Le Borgne T., Dentz M., and Carrera J. (2008) Lagrangian Statistical Model for Transport in Highly Heterogeneous Velocity Fields. Phys. Rev. Lett. 101, 090601 [3] Kang, P. K., T. Le Borgne, M. Dentz, O. Bour, and R. Juanes (2015), Impact of velocity correlation and distribution on transport in fractured media : Field evidence and theoretical model, Water Resour. Res., 51, 940-959 [4] Dorn C., Linde N., Le Borgne T., O. Bour and L. Baron (2011) Single-hole GPR reflection imaging of solute transport in a granitic aquifer Geophys. Res. Lett. Vol.38, L08401

Effect of Cervical Siphon of External and Internal Carotid Arteries.

PubMed

Singh, Rajani; Tubbs, Richard Shane

2017-10-01

Variant courses, configuration, and branching pattern of the external and internal carotid arteries, especially when curved in S-shape, are important for hemodynamic changes and clinical implications. Therefore, the aim of the study is to report abnormal cervical siphons observed in external and internal carotid arteries to explore clinical significance by review of literature and hemodynamic changes theoretically.The right common carotid artery bifurcated into external and internal carotid arteries at the level of the upper border of thyroid cartilage in a 70-year-old female cadaver. After bifurcation, the external carotid artery underwent severe tortuosity coursing through 5 bends at points A, B, C, D, and E from its origin to termination and 2 bends at A' and B' in internal carotid artery in the cervical region. The angles between inflow and out flow of the blood at the bends were measured and the change in velocity at each bend was computed for both arteries. Hemodynamic changes were calculated, compared and relevant clinical complications were theoretically correlated.The angles of 20°, 30°, 51°, 52°, 60°, and 28°, 48° were formed by 5 bends of external and 2 bends of internal carotid arteries, respectively. The curved courses of these arteries caused reduction in velocity/stasis, turbulence, and low shear stress. Such kinks might cause stroke, ischemia and mistaken for tumors and abscess in imagery leading to or otherwise producing iatrogenic repercussions. This study will be useful for anatomists, clinicians, and radiologists.

Computational Design of Short Pulse Laser Driven Iron Opacity Measurements at Stellar-Relevant Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Madison E.

Opacity is a critical parameter in the simulation of radiation transport in systems such as inertial con nement fusion capsules and stars. The resolution of current disagreements between solar models and helioseismological observations would bene t from experimental validation of theoretical opacity models. Overall, short pulse laser heated iron experiments reaching stellar-relevant conditions have been designed with consideration of minimizing tamper emission and optical depth effects while meeting plasma condition and x-ray emission goals.

Experimental and Theoretical Study of Heat Conduction for Air up to 5000 K

NASA Technical Reports Server (NTRS)

Peng, Tzy-Cheng; Ahtye, Warren F.

1961-01-01

The theoretical value of the integral of thermal conductivity is compared with the experimental values from shock-tube measurements. The particular case considered is the one-dimensional nonsteady flow of heat through air at constant pressure. This approach has been previously described in NASA TR R-27. experiment was uncertain because of the large scatter in the experimental data. In this paper, an attempt is made to improve the correlation by use of a more refined calculation of the integral of thermal conductivity, and by use of improved experimental techniques and instrumentation. As a result of these changes, a much closer correlation is shown between the experimental and theoretical heat-flux potentials. This indicates that the predicted values of the coefficient of thermal conductivity for high-temperature air may be suitably accurate for many engineering needs, up to the limits of the test (4600 K).

Theoretical study of the diatomic alkali and alkaline-earth oxides

NASA Technical Reports Server (NTRS)

Langhoff, S. R.; Bauschlicher, C. W., Jr.; Partridge, H.

1986-01-01

Theoretical dissociation energies for the ground states of the alkali and alkaline earth oxides are presented that are believed to be accurate to 0.1 eV. The 2 Pi - 2 Sigma + separations for the alkali oxides are found to be more sensitive to basis set than to electron correlation. Predicted 2 Pi ground states for LiO and NaO and 2 Sigma + ground states for RbO and CsO are found to be in agreement with previous theoretical and experimental work. For KO, a 2 Sigma + state is found at both the numerical Hartree-Fock (NHF) level and at the singles plus doubles configuration interaction level using a Slater basis set that is within 0.02 eV of the NHF limit. It is found that an accurate balanced treatment of the two states requires correlating the electrons on both the metal and oxide ion.

Theoretical study of transition-metal ions bound to benzene

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R.

1992-01-01

Theoretical binding energies are reported for all first-row and selected second-row transition metal ions (M+) bound to benzene. The calculations employ basis sets of at least double-zeta plus polarization quality and account for electron correlation using the modified coupled-pair functional method. While the bending is predominantly electrostatic, the binding energies are significantly increased by electron correlation, because the donation from the metal d orbitals to the benzene pi* orbitals is not well described at the self-consistent-field level. The uncertainties in the computed binding energies are estimated to be about 5 kcal/mol. Although the calculated and experimental binding energies generally agree to within their combined uncertainties, it is likely that the true binding energies lie in the lower portion of the experimental range. This is supported by the very good agreement between the theoretical and recent experimental binding energies for AgC6H6(+).

Turbidity determination of the critical exponent eta in the liquid-liquid mixture methanol and cyclohexane.

PubMed

Lytle, Amy; Jacobs, D T

2004-03-22

The turbidity of the liquid-liquid mixture methanol-cyclohexane has been measured very near its critical point and used to test competing theoretical predictions and to determine the critical correlation-correction exponent eta. By measuring the ratio of the transmitted to incident light intensities over five decades in reduced temperature, we are able to determine that Ferrell's theoretical prediction for the turbidity explains the data with the correlation length amplitude xi0=0.330+/-0.003 nm and critical exponents eta=0.041+/-0.005 and nu=0.632+/-0.002. These values are consistent with the values measured before for xi0 in this system and with the exponents predicted by theory. The data allow five different theoretical expressions to be tested and to select two as being equivalent when very close to the critical point. (c) 2004 American Institute of Physics

Topological Defects in Liquid Crystals: Studying the Correlation between Defects and Curvature

NASA Astrophysics Data System (ADS)

Melton, Charles

2015-03-01

Topological defects have recently been the subject of many fascinating studies in soft condensed matter physics. In particular, linking the evolution of topological defects to curvature changes has been a focus, leading possible applications in the areas such as cosmetics, pharmaceuticals, and electronics. In this study, defects in nematic liquid crystal droplets are investigated via laboratory and theoretical techniques. Nematic liquid crystal defects are reproduced via Monte Carlo simulations using a modified 2D XY-Model Hamiltonian. The simulation is performed on a curved surface to replicate a nematic droplet and examine possible defect configurations. To complement this theoretical work, we have trapped nematic droplets inside a dual-beam optical trap. This system allows controllable non-contact droplet deformation on a microscope based platform. Future work will focus on using the trap to stretch nematic droplets, correlating the changing topological defects with theoretical predictions.

Optical spectra and band structure of Ag(x)Ga(x)Ge(1-x)Se2 (x = 0.333, 0.250, 0.200, 0.167) single crystals: experiment and theory.

PubMed

Reshak, A H; Parasyuk, O V; Fedorchuk, A O; Kamarudin, H; Auluck, S; Chyský, J

2013-12-05

Theoretical and experimental studies of the Ag(x)Ga(x)Ge(1-x)Se2 (x = 0.333, 0.250, 0.200, 0.167) single crystals are performed. These crystals possess a lot of intrinsic defects which are responsible for their optoelectronic features. The theoretical investigations were performed by means of DFT calculations using different exchange-correlation potentials. The experimental studies were carried out using the modulated VUV ellipsometry for dielectric constants and birefringence studies. The comparison of the structure obtained from X-ray with the theoretically optimized structure is presented. The crucial role of the intrinsic defect states is manifested in the choice of the exchange correlation potential used. The data may be applicable for a large number of the ternary chalcogenides which are sensitive to the presence of the local disordered states near the band edges.

Remote sensing of subsurface water temperature by Raman scattering.

PubMed

Leonard, D A; Caputo, B; Hoge, F E

1979-06-01

The application of Raman scattering to remote sensing of subsurface water temperature and salinity is considered, and both theoretical and experimental aspects of the technique are discussed. Recent experimental field measurements obtained in coastal waters and on a trans-Atlantic/Mediterranean research cruise are correlated with theoretical expectations. It is concluded that the Raman technique for remote sensing of subsurface water temperature has been brought from theoretical and laboratory stages to the point where practical utilization can now be developed.

Supersonic wings with significant leading-edge thrust at cruise

NASA Technical Reports Server (NTRS)

Robins, A. W.; Carlson, H. W.; Mack, R. J.

1980-01-01

Experimental/theoretical correlations are presented which show that significant levels of leading-edge thrust are possible at supersonic speeds for certain planforms having the geometry to support the theoretical thrust-distribution potential. The new analytical process employed provides not only the level of leading-edge thrust attainable but also the spanwise distribution of both it and that component of full theoretical thrust which acts as vortex lift. Significantly improved aerodynamic performance in the moderate supersonic speed regime is indicated.

Detection of internal cracks in rubber composite structures using an impact acoustic modality

NASA Astrophysics Data System (ADS)

Shen, Q.; Kurfess, T. R.; Omar, M.; Gramling, F.

2014-01-01

The objective of this study is to investigate the use of impact acoustic signals to non-intrusively inspect rubber composite structures for the presence of internal cracks, such as those found in an automobile tyre. Theoretical contact dynamic models for both integral and defective rubber structures are developed based on Hertz's impact model, further modified for rubber composite materials. The model generates the prediction of major impact dynamic quantities, namely the maximum impact force, impact duration and contact deformation; such parameters are also theoretically proven to be correlated with the presence of internal cracks. The tyre structures are simplified into cubic rubber blocks, to mitigate complexity for analytical modelling. Both impact force and impact sound signals are measured experimentally, and extraction of useful features from both signals for defect identification is achieved. The impact force produces two direct measurements of theoretical impact dynamic quantities. A good correlation between these experimental discriminators and the theoretical dynamic quantities provide validation for the contact dynamics models. Defect discriminators extracted from the impact sound are dependent on both time- and frequency-domain analyses. All the discriminators are closely connected with the theoretical dynamic quantities and experimentally verified as good indicators of internal cracks in rubber composite structures.

Heat perturbation spreading in the Fermi-Pasta-Ulam-β system with next-nearest-neighbor coupling: Competition between phonon dispersion and nonlinearity

NASA Astrophysics Data System (ADS)

Xiong, Daxing

2017-06-01

We employ the heat perturbation correlation function to study thermal transport in the one-dimensional Fermi-Pasta-Ulam-β lattice with both nearest-neighbor and next-nearest-neighbor couplings. We find that such a system bears a peculiar phonon dispersion relation, and thus there exists a competition between phonon dispersion and nonlinearity that can strongly affect the heat correlation function's shape and scaling property. Specifically, for small and large anharmoncities, the scaling laws are ballistic and superdiffusive types, respectively, which are in good agreement with the recent theoretical predictions; whereas in the intermediate range of the nonlinearity, we observe an unusual multiscaling property characterized by a nonmonotonic delocalization process of the central peak of the heat correlation function. To understand these multiscaling laws, we also examine the momentum perturbation correlation function and find a transition process with the same turning point of the anharmonicity as that shown in the heat correlation function. This suggests coupling between the momentum transport and the heat transport, in agreement with the theoretical arguments of mode cascade theory.

Correlation filtering in financial time series (Invited Paper)

NASA Astrophysics Data System (ADS)

Aste, T.; Di Matteo, Tiziana; Tumminello, M.; Mantegna, R. N.

2005-05-01

We apply a method to filter relevant information from the correlation coefficient matrix by extracting a network of relevant interactions. This method succeeds to generate networks with the same hierarchical structure of the Minimum Spanning Tree but containing a larger amount of links resulting in a richer network topology allowing loops and cliques. In Tumminello et al.,1 we have shown that this method, applied to a financial portfolio of 100 stocks in the USA equity markets, is pretty efficient in filtering relevant information about the clustering of the system and its hierarchical structure both on the whole system and within each cluster. In particular, we have found that triangular loops and 4 element cliques have important and significant relations with the market structure and properties. Here we apply this filtering procedure to the analysis of correlation in two different kind of interest rate time series (16 Eurodollars and 34 US interest rates).

Nonlinear bivariate dependency of price-volume relationships in agricultural commodity futures markets: A perspective from Multifractal Detrended Cross-Correlation Analysis

NASA Astrophysics Data System (ADS)

He, Ling-Yun; Chen, Shu-Peng

2011-01-01

Nonlinear dependency between characteristic financial and commodity market quantities (variables) is crucially important, especially between trading volume and market price. Studies on nonlinear dependency between price and volume can provide practical insights into market trading characteristics, as well as the theoretical understanding of market dynamics. Actually, nonlinear dependency and its underlying dynamical mechanisms between price and volume can help researchers and technical analysts in understanding the market dynamics by integrating the market variables, instead of investigating them in the current literature. Therefore, for investigating nonlinear dependency of price-volume relationships in agricultural commodity futures markets in China and the US, we perform a new statistical test to detect cross-correlations and apply a new methodology called Multifractal Detrended Cross-Correlation Analysis (MF-DCCA), which is an efficient algorithm to analyze two spatially or temporally correlated time series. We discuss theoretically the relationship between the bivariate cross-correlation exponent and the generalized Hurst exponents for time series of respective variables. We also perform an empirical study and find that there exists a power-law cross-correlation between them, and that multifractal features are significant in all the analyzed agricultural commodity futures markets.

The status of the concept of 'phoneme' in psycholinguistics.

PubMed

Uppstad, Per Henning; Tønnessen, Finn Egil

2010-10-01

The notion of the phoneme counts as a break-through of modern theoretical linguistics in the early twentieth century. It paved the way for descriptions of distinctive features at different levels in linguistics. Although it has since then had a turbulent existence across altering theoretical positions, it remains a powerful concept of a fundamental unit in spoken language. At the same time, its conceptual status remains highly unclear. The present article aims to clarify the status of the concept of 'phoneme' in psycholinguistics, based on the scientific concepts of description, understanding and explanation. Theoretical linguistics has provided mainly descriptions. The ideas underlying this article are, first, that these descriptions may not be directly relevant to psycholinguistics and, second, that psycholinguistics in this sense is not a sub-discipline of theoretical linguistics. Rather, these two disciplines operate with different sets of features and with different orientations when it comes to the scientific concepts of description, understanding and explanation.

Rockfall travel distances theoretical distributions

NASA Astrophysics Data System (ADS)

Jaboyedoff, Michel; Derron, Marc-Henri; Pedrazzini, Andrea

2017-04-01

The probability of propagation of rockfalls is a key part of hazard assessment, because it permits to extrapolate the probability of propagation of rockfall either based on partial data or simply theoretically. The propagation can be assumed frictional which permits to describe on average the propagation by a line of kinetic energy which corresponds to the loss of energy along the path. But loss of energy can also be assumed as a multiplicative process or a purely random process. The distributions of the rockfall block stop points can be deduced from such simple models, they lead to Gaussian, Inverse-Gaussian, Log-normal or exponential negative distributions. The theoretical background is presented, and the comparisons of some of these models with existing data indicate that these assumptions are relevant. The results are either based on theoretical considerations or by fitting results. They are potentially very useful for rockfall hazard zoning and risk assessment. This approach will need further investigations.

Role of the phase-matching condition in nondegenerate four-wave mixing in hot vapors for the generation of squeezed states of light

NASA Astrophysics Data System (ADS)

Turnbull, M. T.; Petrov, P. G.; Embrey, C. S.; Marino, A. M.; Boyer, V.

2013-09-01

Nondegenerate forward four-wave mixing in hot atomic vapors has been shown to produce strong quantum correlations between twin beams of light [McCormick , Opt. Lett.OPLEDP0146-959210.1364/OL.32.000178 32, 178 (2007)], in a configuration which minimizes losses by absorption. In this paper, we look at the role of the phase-matching condition in the trade-off that occurs between the efficiency of the nonlinear process and the absorption of the twin beams. To this effect, we develop a semiclassical model by deriving the atomic susceptibilities in the relevant double-Λ configuration and by solving the classical propagation of the twin-beam fields for parameters close to those found in typical experiments. These theoretical results are confirmed by a simple experimental study of the nonlinear gain experienced by the twin beams as a function of the phase mismatch. The model shows that the amount of phase mismatch is key to the realization of the physical conditions in which the absorption of the twin beams is minimized while the cross coupling between the twin beams is maintained at the level required for the generation of strong quantum correlations. The optimum is reached when the four-wave mixing process is not phase matched for fully resonant four-wave mixing.

Physician communication in the operating room: expanding application of face-negotiation theory to the health communication context.

PubMed

Kirschbaum, Kristin

2012-01-01

Communication variables that are associated with face-negotiation theory were examined in a sample of operating-room physicians. A survey was administered to anesthesiologists and surgeons at a teaching hospital in the southwestern United States to measure three variables commonly associated with face-negotiation theory: conflict-management style, face concern, and self-construal. The survey instrument that was administered to physicians includes items that measured these three variables in previous face-negotiation research with slight modification of item wording for relevance in the medical setting. The physician data were analyzed using confirmatory factor analysis, Pearson's correlations, and t-tests. Results of this initial investigation showed that variables associated with face-negotiation theory were evident in the sample physician population. In addition, the correlations were similar among variables in the medical sample as those found in previous face-negotiation research. Finally, t-tests suggest variance between anesthesiologists and surgeons on specific communication variables. These findings suggest three implications that warrant further investigation with expanded sample size: (1) An intercultural communication theory and instrument can be utilized for health communication research; (2) as applied in a medical context, face-negotiation theory can be expanded beyond traditional intercultural communication boundaries; and (3) theoretically based communication structures applied in a medical context could help explain physician miscommunication in the operating room to assist future design of communication training programs for operating-room physicians.

Systematic expansion in the order parameter for replica theory of the dynamical glass transition.

PubMed

Jacquin, Hugo; Zamponi, Francesco

2013-03-28

It has been shown recently that predictions from mode-coupling theory for the glass transition of hard-spheres become increasingly bad when dimensionality increases, whereas replica theory predicts a correct scaling. Nevertheless if one focuses on the regime around the dynamical transition in three dimensions, mode-coupling results are far more convincing than replica theory predictions. It seems thus necessary to reconcile the two theoretic approaches in order to obtain a theory that interpolates between low-dimensional, mode-coupling results, and "mean-field" results from replica theory. Even though quantitative results for the dynamical transition issued from replica theory are not accurate in low dimensions, two different approximation schemes--small cage expansion and replicated hyper-netted-chain (RHNC)--provide the correct qualitative picture for the transition, namely, a discontinuous jump of a static order parameter from zero to a finite value. The purpose of this work is to develop a systematic expansion around the RHNC result in powers of the static order parameter, and to calculate the first correction in this expansion. Interestingly, this correction involves the static three-body correlations of the liquid. More importantly, we separately demonstrate that higher order terms in the expansion are quantitatively relevant at the transition, and that the usual mode-coupling kernel, involving two-body direct correlation functions of the liquid, cannot be recovered from static computations.

TASI Lectures on Cosmological Observables and String Theory

NASA Astrophysics Data System (ADS)

Silverstein, Eva

These lectures provide an updated pedagogical treatment of the theoretical structure and phenomenology of some basic mechanisms for inflation, along with an overview of the structure of cosmological uplifts of holographic duality. A full treatment of the problem requires `ultraviolet completion' because of the sensitivity of inflation to quantum gravity effects, including back reaction and non-adiabatic production of heavy degrees of freedom. Cosmological observations imply accelerated expansion of the late universe, and provide increasingly precise constraints and discovery potential on the amplitude and shape of primordial tensor and scalar perturbations, and some of their correlation functions. Most backgrounds of string theory have positive potential energy, with a rich but still highly constrained landscape of solutions. The theory contains novel mechanisms for inflation, some subject to significant observational tests, with highly UV-sensitive tensor mode measurements being a prime example along with certain shapes of primordial correlation functions. Although the detailed ultraviolet completion is not accessible experimentally, some of these mechanisms directly stimulate a more systematic analysis of the space of low energy theories and signatures relevant for analysis of data, which is sensitive to physics orders of magnitude above the energy scale of inflation as a result of long time evolution (dangerous irrelevance) and the substantial amount of data (allowing constraints on quantities with signal/noise. Portions of these lectures appeared previously in Les Houches 2013, "Post-Planck Cosmology".

Validation of the CPAP Habit Index-5: A Tool to Understand Adherence to CPAP Treatment in Patients with Obstructive Sleep Apnea

PubMed Central

Broström, Anders; Nilsen, Per; Fridlund, Bengt; Årestedt, Kristofer

2014-01-01

Long-term adherence to continuous positive airway pressure (CPAP) is low among patients with obstructive sleep apnea (OSA). The potential role of “habit” in sustaining adherence to CPAP use has not been studied. This study aimed to establish the relevance of habit to CPAP adherence, via validation of an adaptation of the Self-Report Habit Index (the CPAP Habit Index-5; CHI-5). Analyses focused on the homogeneity, reliability, and factor structure of the CHI-5 and, in line with theoretical predictions, its utility as a predictor of long-term CPAP adherence in middle-aged patients with OSA. A prospective longitudinal design was used. 117 patients with objectively verified OSA intended for CPAP treatment were recruited. Data was collected via clinical examinations, respiratory recordings, questionnaires, and CPAP devices at baseline, 2 weeks, 6 months, and 12 months. The CHI-5 showed satisfactory homogeneity interitem correlations (0.42–0.93), item-total correlations (0.58–0.91), and reliability (α = 0.92). CHI-5 data at 6 months showed a one-factor solution and predicted 63% of variance in total CPAP use hours after 12 months. Based on the satisfactory measurement properties and the high amount of CPAP use variance it explained, the CHI-5 can be seen as a useful tool in clinical practice. PMID:24876975

Dynamical Vertex Approximation for the Hubbard Model

NASA Astrophysics Data System (ADS)

Toschi, Alessandro

A full understanding of correlated electron systems in the physically relevant situations of three and two dimensions represents a challenge for the contemporary condensed matter theory. However, in the last years considerable progress has been achieved by means of increasingly more powerful quantum many-body algorithms, applied to the basic model for correlated electrons, the Hubbard Hamiltonian. Here, I will review the physics emerging from studies performed with the dynamical vertex approximation, which includes diagrammatic corrections to the local description of the dynamical mean field theory (DMFT). In particular, I will first discuss the phase diagram in three dimensions with a special focus on the commensurate and incommensurate magnetic phases, their (quantum) critical properties, and the impact of fluctuations on electronic lifetimes and spectral functions. In two dimensions, the effects of non-local fluctuations beyond DMFT grow enormously, determining the appearance of a low-temperature insulating behavior for all values of the interaction in the unfrustrated model: Here the prototypical features of the Mott-Hubbard metal-insulator transition, as well as the existence of magnetically ordered phases, are completely overwhelmed by antiferromagnetic fluctuations of exponentially large extension, in accordance with the Mermin-Wagner theorem. Eventually, by a fluctuation diagnostics analysis of cluster DMFT self-energies, the same magnetic fluctuations are identified as responsible for the pseudogap regime in the holed-doped frustrated case, with important implications for the theoretical modeling of the cuprate physics.

Inspecting the Dangers of Feeling like a Fake: An Empirical Investigation of the Impostor Phenomenon in the World of Work

PubMed Central

Neureiter, Mirjam; Traut-Mattausch, Eva

2016-01-01

To investigate the link between the impostor phenomenon (IP), career self-management (CSM) factors, and work-relevant outcomes, we looked at the IP's impact on career optimism, career adaptability, and knowledge of the job market, as well as on employee- and organizationally-relevant outcomes. We analyzed data from 238 working professionals (57% female) using parallel multiple mediation analyses. The results revealed that the IP was negatively related to all work-relevant outcomes through decreased CSM factors, which were subsequently associated with the outcomes. As hypothesized, employee-relevant subjective outcomes were mediated by optimism and employee-relevant objective (i.e., economic) outcomes by adaptability and knowledge. Additional mediating effects occurred. Regarding organizationally relevant outcomes, adaptability mediated the IP's impact on organizational citizenship behavior. The IP was only indirectly related to continuance commitment through adaptability and to affective commitment through optimism. We discuss the theoretical and practical implications and offer ideas for future research. PMID:27729882

Valence electronic properties of porphyrin derivatives.

PubMed

Stenuit, G; Castellarin-Cudia, C; Plekan, O; Feyer, V; Prince, K C; Goldoni, A; Umari, P

2010-09-28

We present a combined experimental and theoretical investigation of the valence electronic structure of porphyrin-derived molecules. The valence photoemission spectra of the free-base tetraphenylporphyrin and of the octaethylporphyrin molecule were measured using synchrotron radiation and compared with theoretical spectra calculated using the GW method and the density-functional method within the generalized gradient approximation. Only the GW results could reproduce the experimental data. We found that the contribution to the orbital energies due to electronic correlations has the same linear behavior in both molecules, with larger deviations in the vicinity of the HOMO level. This shows the importance of adequate treatment of electronic correlations in these organic systems.

Calculation of the Lateral Stability of a Directly Coupled Tandem-Towed Fighter Airplane and Correlation with Experimental Data

NASA Technical Reports Server (NTRS)

Shanks, Robert E.

1958-01-01

A theoretical method is presented for predicting the dynamic lateral stability characteristics of an airplane towed in tandem by a much larger airplane. Values of period and time to damp to one-half amplitude and rolling motions calculated by an analog computer have been correlated with results of two experimental investigations conducted in the Langley free-flight tunnel which were part of a U.S. Air Force program (Project FICON) to develop a satisfactory arrangement by which a bomber could tow a parasite fighter. In general, the theoretical results agree with the experimental results.

The cosmological lithium problem revisited

NASA Astrophysics Data System (ADS)

Bertulani, C. A.; Mukhamedzhanov, A. M.; Shubhchintak

2016-07-01

After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleosynthesis epoch. Last but not least, we discuss possible solutions within nuclear physics realm. The impact of recent measurements of relevant nuclear reaction cross sections for the Big Bang nucleosynthesis based on indirect methods is also assessed. Although our attempts may not able to explain the observed discrepancies between theory and observations, they suggest theoretical developments that can be useful also for stellar nucleosynthesis.

Charting the future course of rural health and remote health in Australia: Why we need theory.

PubMed

Bourke, Lisa; Humphreys, John S; Wakerman, John; Taylor, Judy

2010-04-01

This paper argues that rural and remote health is in need of theoretical development. Based on the authors' discussions, reflections and critical analyses of literature, this paper proposes key reasons why rural and remote health warrants the development of theoretical frameworks. The paper cites five reasons why theory is needed: (i) theory provides an approach for how a topic is studied; (ii) theory articulates key assumptions in knowledge development; (iii) theory systematises knowledge, enabling it to be transferable; (iv) theory provides predictability; and (v) theory enables comprehensive understanding. This paper concludes with a call for theoretical development in both rural and remote health to expand its knowledge and be more relevant to improving health care for rural Australians.

Theoretical study on the sound absorption of electrolytic solutions. I. Theoretical formulation.

PubMed

Yamaguchi, T; Matsuoka, T; Koda, S

2007-04-14

A theory is formulated that describes the sound absorption of electrolytic solutions due to the relative motion of ions, including the formation of ion pairs. The theory is based on the Kubo-Green formula for the bulk viscosity. The time correlation function of the pressure is projected onto the bilinear product of the density modes of ions. The time development of the product of density modes is described by the diffusive limit of the generalized Langevin equation, and approximate expressions for the three- and four-body correlation functions required are given with the hypernetted-chain integral equation theory. Calculations on the aqueous solutions of model electrolytes are performed. It is demonstrated that the theory describes both the activated barrier crossing between contact and solvent-separated ion pairs and the Coulombic correlation between ions.

Theoretical study on the sound absorption of electrolytic solutions. I. Theoretical formulation

NASA Astrophysics Data System (ADS)

Yamaguchi, T.; Matsuoka, T.; Koda, S.

2007-04-01

A theory is formulated that describes the sound absorption of electrolytic solutions due to the relative motion of ions, including the formation of ion pairs. The theory is based on the Kubo-Green formula for the bulk viscosity. The time correlation function of the pressure is projected onto the bilinear product of the density modes of ions. The time development of the product of density modes is described by the diffusive limit of the generalized Langevin equation, and approximate expressions for the three- and four-body correlation functions required are given with the hypernetted-chain integral equation theory. Calculations on the aqueous solutions of model electrolytes are performed. It is demonstrated that the theory describes both the activated barrier crossing between contact and solvent-separated ion pairs and the Coulombic correlation between ions.

Strong correlation effects in theoretical STM studies of magnetic adatoms

NASA Astrophysics Data System (ADS)

Dang, Hung T.; dos Santos Dias, Manuel; Liebsch, Ansgar; Lounis, Samir

2016-03-01

We present a theoretical study for the scanning tunneling microscopy (STM) spectra of surface-supported magnetic nanostructures, incorporating strong correlation effects. As concrete examples, we study Co and Mn adatoms on the Cu(111) surface, which are expected to represent the opposite limits of Kondo physics and local moment behavior, using a combination of density functional theory and both quantum Monte Carlo and exact diagonalization impurity solvers. We examine in detail the effects of temperature T , correlation strength U , and impurity d electron occupancy Nd on the local density of states. We also study the effective coherence energy scale, i.e., the Kondo temperature TK, which can be extracted from the STM spectra. Theoretical STM spectra are computed as a function of STM tip position relative to each adatom. Because of the multiorbital nature of the adatoms, the STM spectra are shown to consist of a complicated superposition of orbital contributions, with different orbital symmetries, self-energies, and Kondo temperatures. For a Mn adatom, which is close to half-filling, the STM spectra are featureless near the Fermi level. On the other hand, the quasiparticle peak for a Co adatom gives rise to strongly position-dependent Fano line shapes.

Uncovering many-body correlations in nanoscale nuclear spin baths by central spin decoherence

PubMed Central

Ma, Wen-Long; Wolfowicz, Gary; Zhao, Nan; Li, Shu-Shen; Morton, John J.L.; Liu, Ren-Bao

2014-01-01

Central spin decoherence caused by nuclear spin baths is often a critical issue in various quantum computing schemes, and it has also been used for sensing single-nuclear spins. Recent theoretical studies suggest that central spin decoherence can act as a probe of many-body physics in spin baths; however, identification and detection of many-body correlations of nuclear spins in nanoscale systems are highly challenging. Here, taking a phosphorus donor electron spin in a 29Si nuclear spin bath as our model system, we discover both theoretically and experimentally that many-body correlations in nanoscale nuclear spin baths produce identifiable signatures in decoherence of the central spin under multiple-pulse dynamical decoupling control. We demonstrate that under control by an odd or even number of pulses, the central spin decoherence is principally caused by second- or fourth-order nuclear spin correlations, respectively. This study marks an important step toward studying many-body physics using spin qubits. PMID:25205440

Measurement of long-range angular correlations and azimuthal anisotropies in high-multiplicity p + Au collisions at s NN = 200 GeV

DOE PAGES

Aidala, C.; Akiba, Y.; Alfred, M.; ...

2017-03-24

Inmore » this paper, we present measurements of long-range angular correlations and the transverse momentum dependence of elliptic flow ν 2 in high-multiplicity p + Au collisions at s NN = 200 GeV. A comparison of these results to previous measurements in high-multiplicity d + Au and 3He + Au collisions demonstrates a relation between ν 2 and the initial collision eccentricity ε 2, suggesting that the observed momentum-space azimuthal anisotropies in these small systems have a collective origin and reflect the initial geometry. Good agreement is observed between the measured ν 2 and hydrodynamic calculations for all systems, and an argument disfavoring theoretical explanations based on initial momentum-space domain correlations is presented. Finally, the set of measurements presented here allows us to leverage the distinct intrinsic geometry of each of these systems to distinguish between different theoretical descriptions of the long-range correlations observed in small collision systems.« less

Measurement of long-range angular correlations and azimuthal anisotropies in high-multiplicity p + Au collisions at s NN = 200 GeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aidala, C.; Akiba, Y.; Alfred, M.

Inmore » this paper, we present measurements of long-range angular correlations and the transverse momentum dependence of elliptic flow ν 2 in high-multiplicity p + Au collisions at s NN = 200 GeV. A comparison of these results to previous measurements in high-multiplicity d + Au and 3He + Au collisions demonstrates a relation between ν 2 and the initial collision eccentricity ε 2, suggesting that the observed momentum-space azimuthal anisotropies in these small systems have a collective origin and reflect the initial geometry. Good agreement is observed between the measured ν 2 and hydrodynamic calculations for all systems, and an argument disfavoring theoretical explanations based on initial momentum-space domain correlations is presented. Finally, the set of measurements presented here allows us to leverage the distinct intrinsic geometry of each of these systems to distinguish between different theoretical descriptions of the long-range correlations observed in small collision systems.« less

Photon correlation in single-photon frequency upconversion.

PubMed

Gu, Xiaorong; Huang, Kun; Pan, Haifeng; Wu, E; Zeng, Heping

2012-01-30

We experimentally investigated the intensity cross-correlation between the upconverted photons and the unconverted photons in the single-photon frequency upconversion process with multi-longitudinal mode pump and signal sources. In theoretical analysis, with this multi-longitudinal mode of both signal and pump sources system, the properties of the signal photons could also be maintained as in the single-mode frequency upconversion system. Experimentally, based on the conversion efficiency of 80.5%, the joint probability of simultaneously detecting at upconverted and unconverted photons showed an anti-correlation as a function of conversion efficiency which indicated the upconverted photons were one-to-one from the signal photons. While due to the coherent state of the signal photons, the intensity cross-correlation function g(2)(0) was shown to be equal to unity at any conversion efficiency, agreeing with the theoretical prediction. This study will benefit the high-speed wavelength-tunable quantum state translation or photonic quantum interface together with the mature frequency tuning or longitudinal mode selection techniques.

Measurement of long-range angular correlations and azimuthal anisotropies in high-multiplicity p +Au collisions at √{sNN}=200 GeV

NASA Astrophysics Data System (ADS)

Aidala, C.; Akiba, Y.; Alfred, M.; Andrieux, V.; Aoki, K.; Apadula, N.; Asano, H.; Ayuso, C.; Azmoun, B.; Babintsev, V.; Bandara, N. S.; Barish, K. N.; Bathe, S.; Bazilevsky, A.; Beaumier, M.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Blau, D. S.; Boer, M.; Bok, J. S.; Brooks, M. L.; Bryslawskyj, J.; Bumazhnov, V.; Butler, C.; Campbell, S.; Canoa Roman, V.; Cervantes, R.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Citron, Z.; Connors, M.; Cronin, N.; Csanád, M.; Csörgő, T.; Danley, T. W.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dion, A.; Dixit, D.; Do, J. H.; Drees, A.; Drees, K. A.; Dumancic, M.; Durham, J. M.; Durum, A.; Elder, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fan, W.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukuda, Y.; Gal, C.; Gallus, P.; Garg, P.; Ge, H.; Giordano, F.; Goto, Y.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guragain, H.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamilton, H. F.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Haseler, T. O. S.; He, X.; Hemmick, T. K.; Hill, J. C.; Hill, K.; Hollis, R. S.; Homma, K.; Hong, B.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Imai, K.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Ito, Y.; Ivanishchev, D.; Jacak, B. V.; Jezghani, M.; Ji, Z.; Jiang, X.; Johnson, B. M.; Jorjadze, V.; Jouan, D.; Jumper, D. S.; Kang, J. H.; Kapukchyan, D.; Karthas, S.; Kawall, D.; Kazantsev, A. V.; Khachatryan, V.; Khanzadeev, A.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, M. H.; Kim, M.; Kincses, D.; Kistenev, E.; Klatsky, J.; Kline, P.; Koblesky, T.; Kotov, D.; Kudo, S.; Kurita, K.; Kwon, Y.; Lajoie, J. G.; Lallow, E. O.; Lebedev, A.; Lee, S.; Leitch, M. J.; Leung, Y. H.; Lewis, N. A.; Li, X.; Lim, S. H.; Liu, L. D.; Liu, M. X.; Loggins, V.-R.; Loggins, V.-R.; Lovasz, K.; Lynch, D.; Majoros, T.; Makdisi, Y. I.; Makek, M.; Malaev, M.; Manko, V. I.; Mannel, E.; Masuda, H.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Mendoza, M.; Mignerey, A. C.; Mihalik, D. E.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Mitsuka, G.; Miyasaka, S.; Mizuno, S.; Montuenga, P.; Moon, T.; Morrison, D. P.; Morrow, S. I. M.; Murakami, T.; Murata, J.; Nagai, K.; Nagashima, K.; Nagashima, T.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakano, K.; Nattrass, C.; Niida, T.; Nouicer, R.; Novák, T.; Novitzky, N.; Novotny, R.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ottino, G. J.; Ozawa, K.; Pantuev, V.; Papavassiliou, V.; Park, J. S.; Park, S.; Pate, S. F.; Patel, M.; Peng, W.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perezlara, C. E.; Perry, J.; Petti, R.; Phipps, M.; Pinkenburg, C.; Pisani, R. P.; Pun, A.; Purschke, M. L.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richford, D.; Rinn, T.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Runchey, J.; Safonov, A. S.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, K.; Sato, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sexton, A.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shioya, T.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Smith, K. L.; Snowball, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Syed, S.; Sziklai, J.; Takeda, A.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Tarnai, G.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Towell, C. L.; Towell, R. S.; Tserruya, I.; Ueda, Y.; Ujvari, B.; van Hecke, H. W.; Vazquez-Carson, S.; Velkovska, J.; Virius, M.; Vrba, V.; Vukman, N.; Wang, X. R.; Wang, Z.; Watanabe, Y.; Watanabe, Y. S.; Wong, C. P.; Woody, C. L.; Xu, C.; Xu, Q.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamamoto, H.; Yanovich, A.; Yin, P.; Yoo, J. H.; Yoon, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zharko, S.; Zou, L.; Phenix Collaboration

2017-03-01

We present measurements of long-range angular correlations and the transverse momentum dependence of elliptic flow v2 in high-multiplicity p +Au collisions at √{s NN}=200 GeV. A comparison of these results to previous measurements in high-multiplicity d +Au and 3He+Au collisions demonstrates a relation between v2 and the initial collision eccentricity ɛ2, suggesting that the observed momentum-space azimuthal anisotropies in these small systems have a collective origin and reflect the initial geometry. Good agreement is observed between the measured v2 and hydrodynamic calculations for all systems, and an argument disfavoring theoretical explanations based on initial momentum-space domain correlations is presented. The set of measurements presented here allows us to leverage the distinct intrinsic geometry of each of these systems to distinguish between different theoretical descriptions of the long-range correlations observed in small collision systems.

Numerical and Theoretical Considerations for the Design of the AVT-183 Diamond-Wing Experimental Investigations

NASA Technical Reports Server (NTRS)

Boelens, Okko J.; Luckring, James M.; Breitsamter, Christian; Hovelmann, Andreas; Knoth, Florian; Malloy, Donald J.; Deck, Sebatien

2015-01-01

A diamond-wing configuration has been developed to isolate and study blunt-leading edge vortex separation with both computations and experiments. The wing has been designed so that the results are relevant to a more complex Uninhabited Combat Air Vehicle concept known as SACCON. The numerical and theoretical development process for this diamond wing is presented, including a view toward planned wind tunnel experiments. This work was conducted under the NATO Science and Technology Organization, Applied Vehicle Technology panel. All information is in the public domain.

Modelling Catalyst Surfaces Using DFT Cluster Calculations

PubMed Central

Czekaj, Izabela; Wambach, Jörg; Kröcher, Oliver

2009-01-01

We review our recent theoretical DFT cluster studies of a variety of industrially relevant catalysts such as TiO2, γ-Al2O3, V2O5-WO3-TiO2 and Ni/Al2O3. Aspects of the metal oxide surface structure and the stability and structure of metal clusters on the support are discussed as well as the reactivity of surfaces, including their behaviour upon poisoning. It is exemplarily demonstrated how such theoretical considerations can be combined with DRIFT and XPS results from experimental studies. PMID:20057947

Using theories of behaviour to understand transfusion prescribing in three clinical contexts in two countries: development work for an implementation trial.

PubMed

Francis, Jill J; Tinmouth, Alan; Stanworth, Simon J; Grimshaw, Jeremy M; Johnston, Marie; Hyde, Chris; Stockton, Charlotte; Brehaut, Jamie C; Fergusson, Dean; Eccles, Martin P

2009-10-24

Blood transfusion is an essential part of healthcare and can improve patient outcomes. However, like most therapies, it is also associated with significant clinical risks. In addition, there is some evidence of overuse. Understanding the potential barriers and enablers to reduced prescribing of blood products will facilitate the selection of intervention components likely to be effective, thereby reducing the number of costly trials evaluating different implementation strategies. Using a theoretical basis to understand behaviours targeted for change will contribute to a 'basic science' relating to determinants of professional behaviour and how these inform the selection of techniques for changing behaviour. However, it is not clear which theories of behaviour are relevant to clinicians' transfusing behaviour. The aim of this study is to use a theoretical domains framework to identify relevant theories, and to use these theories to identify factors that predict the decision to transfuse. The study involves two steps: interview study and questionnaire study. Using a previously identified framework, we will conduct semi-structured interviews with clinicians to elicit their views about which factors are associated with waiting and further monitoring the patient rather than transfusing red blood cells. Interviews will cover the following theoretical domains: knowledge; skills; social/professional role and identity; beliefs about capabilities; beliefs about consequences; motivation and goals; memory, attention, and decision processes; environmental context and resources; social influences; emotion; behavioural regulation; nature of the behaviour. The interviews will take place independently in Canada and the UK and involve two groups of physicians in each country (UK: adult and neonatal intensive care physicians; Canada: intensive care physicians and orthopaedic surgeons). We will: analyse interview transcript content to select relevant theoretical domains; use consensus processes to map these domains on to theories of behaviour; develop questionnaires based on these theories; and mail them to each group of physicians in the two countries. From our previous work, it is likely that the theories will include: theory of planned behaviour, social cognitive theory and the evidence-based strategy, implementation intention. The questionnaire data will measure predictor variables (theoretical constructs) and outcome variables (intention and clinical decision), and will be analysed using multiple regression analysis. We aim to achieve 150 respondents in each of the four groups for each postal survey.

A theoretical analysis of the current-voltage characteristics of solar cells

NASA Technical Reports Server (NTRS)

Fang, R. C. Y.; Hauser, J. R.

1977-01-01

The correlation of theoretical and experimental data is discussed along with the development of a complete solar cell analysis. The dark current-voltage characteristics, and the parameters for solar cells are analyzed. The series resistance, and impurity gradient effects on solar cells were studied, the effects of nonuniformities on solar cell performance were analyzed.

Dealing with Misbehavior at Schools in Kentucky: Theoretical and Contextual Predictors of Use of Corporal Punishment

ERIC Educational Resources Information Center

McClure, Timothy E.; May, David C.

2008-01-01

To test and compare theoretical explanations of the use of corporal punishment in school, the authors examine how well county-level measures of culture, socioeconomic strain, and social capital predict the prevalence and incidence of corporal punishment in Kentucky schools. Although several variables are significantly correlated with corporal…

Density functional theory and phytochemical study of Pistagremic acid

NASA Astrophysics Data System (ADS)

Ullah, Habib; Rauf, Abdur; Ullah, Zakir; Fazl-i-Sattar; Anwar, Muhammad; Shah, Anwar-ul-Haq Ali; Uddin, Ghias; Ayub, Khurshid

2014-01-01

We report here for the first time a comparative theoretical and experimental study of Pistagremic acid (P.A). We have developed a theoretical model for obtaining the electronic and spectroscopic properties of P.A. The simulated data showed nice correlation with the experimental data. The geometric and electronic properties were simulated at B3LYP/6-31 G (d, p) level of density functional theory (DFT). The optimized geometric parameters of P.A were found consistent with those from X-ray crystal structure. Differences of about 0.01 and 0.15 Å in bond length and 0.19-1.30° degree in the angles, respectively; were observed between the experimental and theoretical data. The theoretical vibrational bands of P.A were found to correlate with the experimental IR spectrum after a common scaling factor of 0.963. The experimental and predicted UV-Vis spectra (at B3LYP/6-31+G (d, p)) have 36 nm differences. This difference from experimental results is because of the condensed phase nature of P.A. Electronic properties such as Ionization Potential (I.P), Electron Affinities (E.A), co-efficient of highest occupied molecular orbital (HOMO), co-efficient of lowest unoccupied molecular orbital (LUMO) of P.A were estimated for the first time however, no correlation can be made with experiment. Inter-molecular interaction and its effect on vibrational (IR), electronic and geometric parameters were simulated by using Formic acid as model for hydrogen bonding in P.A.

The development of a culturally relevant, theoretically driven HPV prevention intervention for urban adolescent females and their parents/guardians.

PubMed

Brawner, Bridgette M; Baker, Jillian L; Voytek, Chelsea D; Leader, Amy; Cashman, Rebecca R; Silverman, Randee; Peter, Nadja; Buchner, Bradley J; Barnes, Christopher A; Jemmott, Loretta S; Frank, Ian

2013-07-01

Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States, accounting for the large majority of cervical cancer and anogenital warts cases. Two HPV vaccines are currently licensed and recommended for women and girls. However, vaccination rates have been suboptimal, with evidence of disparities influencing both uptake and series completion among African American and Hispanic adolescents. There has been a dearth of theory-based, behavioral interventions targeted to prevent HPV infection and increase HPV vaccine uptake among urban adolescents. This article describes the development of two skills-based intervention curricula aimed to increase HPV prevention and vaccination among low-income urban adolescent females 9 to 18 years old. Guided by the theory of planned behavior, elicitation research was conducted to elucidate the social psychological factors that underlie HPV vaccination intentions (N = 141). The findings were subsequently used to identify theoretical mediators of behavioral change to drive the intervention. Culturally relevant strategies to promote HPV vaccination were translated into the curricula content. Both curricula were designed to motivate and empower participants to reduce risk of being infected with HPV. Targeting theoretical mediators of behavioral change, derived from the voices of the community, may prove to be successful in increasing HPV vaccination and preventing HPV.

CO activation pathways and the mechanism of Fischer–Tropsch synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ojeda, Manuel; Nabar, Rahul P.; Nilekar, Anand U.

2010-06-15

Unresolved mechanistic details of monomer formation in Fischer–Tropsch synthesis (FTS) and of its oxygen rejection routes are addressed here by combining kinetic and theoretical analyses of elementary steps on representative Fe and Co surfaces saturated with chemisorbed CO. These studies provide experimental and theoretical evidence for hydrogen-assisted CO activation as the predominant kinetically-relevant step on Fe and Co catalysts at conditions typical of FTS practice. H2 and CO kinetic effects on FTS rates and oxygen rejection selectivity (as H2O or CO2) and density functional theory estimates of activation barriers and binding energies are consistent with H-assisted CO dissociation, but notmore » with the previously accepted kinetic relevance of direct CO dissociation and chemisorbed carbon hydrogenation elementary steps. H-assisted CO dissociation removes O-atoms as H2O, while direct dissociation forms chemisorbed oxygen atoms that desorb as CO2. Direct CO dissociation routes are minor contributors to monomer formation on Fe and may become favored at high temperatures on alkali-promoted catalysts, but not on Co catalysts, which remove oxygen predominantly as H2O because of the preponderance of Hassisted CO dissociation routes. The merging of experiment and theory led to the clarification of persistent mechanistic issues previously unresolved by separate experimental and theoretical inquiries.« less

Quality Assessment of Internationalised Studies: Theory and Practice

ERIC Educational Resources Information Center

Juknyte-Petreikiene, Inga

2013-01-01

The article reviews forms of higher education internationalisation at an institutional level. The relevance of theoretical background of internationalised study quality assessment is highlighted and definitions of internationalised studies quality are presented. Existing methods of assessment of higher education internationalisation are criticised…

Cognitive Architectures for Multimedia Learning

ERIC Educational Resources Information Center

Reed, Stephen K.

2006-01-01

This article provides a tutorial overview of cognitive architectures that can form a theoretical foundation for designing multimedia instruction. Cognitive architectures include a description of memory stores, memory codes, and cognitive operations. Architectures that are relevant to multimedia learning include Paivio's dual coding theory,…

Human Ecology: Persistence and Change.

ERIC Educational Resources Information Center

Hawley, Amos H.

1981-01-01

Demonstrates the relevance of ecology to sociological research and discusses some of the theoretical perspectives embodied in ecology. Examines ecology's emphasis upon the population rather than the individual as the unit of observation and on organizations as products of the interaction of population and environment. (DB)

Lakatos Revisited.

ERIC Educational Resources Information Center

Court, Deborah

1999-01-01

Revisits and reviews Imre Lakatos' ideas on "Falsification and the Methodology of Scientific Research Programmes." Suggests that Lakatos' framework offers an insightful way of looking at the relationship between theory and research that is relevant not only for evaluating research programs in theoretical physics, but in the social…

Education and Social Cohesion for Economic Growth

ERIC Educational Resources Information Center

Camilleri, Mark A.; Camilleri, Adriana

2016-01-01

Relevant theoretical underpinnings suggest that higher education, continuous professional development and training provide numerous opportunities for societal advancement. This contribution posits that interventions in the realms of education can play a significant role in shaping key performance indicators for laudable social outcomes. It…

First cross-section measurements of the reactions Ag,109107(p ,γ )Cd,110108 at energies relevant to the p process

NASA Astrophysics Data System (ADS)

Khaliel, A.; Mertzimekis, T. J.; Asimakopoulou, E.-M.; Kanellakopoulos, A.; Lagaki, V.; Psaltis, A.; Psyrra, I.; Mavrommatis, E.

2017-09-01

Background: One of the primary objectives of the field of Nuclear Astrophysics is the study of the elemental and isotopic abundances in the universe. Although significant progress has been made in understanding the mechanisms behind the production of a large number of nuclides in the isotopic chart, there are still many open questions regarding a number of neutron-deficient nuclei, the p nuclei. To that end, experimentally deduced nuclear reaction cross sections can provide invaluable input to astrophysical models. Purpose: The reactions Ag,109107(p ,γ )Cd,110108 have been studied at energies inside the astrophysically relevant energy window in an attempt to provide experimental data required for the testing of reaction-rate predictions in terms of the statistical model of Hauser-Feshbach around the p nucleus 108Cd. Methods: The experiments were performed with in-beam γ -ray spectroscopy with proton beams accelerated by the Tandem Van de Graaff Accelerator at NCSR "Demokritos" impinging a target of natural silver. A set of high-purity germanium detectors was employed to record the emitted radiation. Results: A first set of total cross-section measurements in radiative proton-capture reactions involving Ag,109107, producing the p -nucleus 108Cd, inside the astrophysically relevant energy window is reported. The experimental results are compared to theoretical calculations, using talys. An overall good agreement between the data and the theoretical calculations has been found. Conclusions: The results reported in this work add new information to the relatively unexplored p process. The present measurements can serve as a reference point in understanding the nuclear parameters in the related astrophysical environments and for future theoretical modeling and experimental works.

Flow, Transport, and Reaction in Porous Media: Percolation Scaling, Critical-Path Analysis, and Effective Medium Approximation

NASA Astrophysics Data System (ADS)

Hunt, Allen G.; Sahimi, Muhammad

2017-12-01

We describe the most important developments in the application of three theoretical tools to modeling of the morphology of porous media and flow and transport processes in them. One tool is percolation theory. Although it was over 40 years ago that the possibility of using percolation theory to describe flow and transport processes in porous media was first raised, new models and concepts, as well as new variants of the original percolation model are still being developed for various applications to flow phenomena in porous media. The other two approaches, closely related to percolation theory, are the critical-path analysis, which is applicable when porous media are highly heterogeneous, and the effective medium approximation—poor man's percolation—that provide a simple and, under certain conditions, quantitatively correct description of transport in porous media in which percolation-type disorder is relevant. Applications to topics in geosciences include predictions of the hydraulic conductivity and air permeability, solute and gas diffusion that are particularly important in ecohydrological applications and land-surface interactions, and multiphase flow in porous media, as well as non-Gaussian solute transport, and flow morphologies associated with imbibition into unsaturated fractures. We describe new applications of percolation theory of solute transport to chemical weathering and soil formation, geomorphology, and elemental cycling through the terrestrial Earth surface. Wherever quantitatively accurate predictions of such quantities are relevant, so are the techniques presented here. Whenever possible, the theoretical predictions are compared with the relevant experimental data. In practically all the cases, the agreement between the theoretical predictions and the data is excellent. Also discussed are possible future directions in the application of such concepts to many other phenomena in geosciences.

Stress-stress correlator in ϕ 4 theory: poles or a cut?

NASA Astrophysics Data System (ADS)

Moore, Guy D.

2018-05-01

We explore the analytical properties of the traceless stress tensor 2-point function at zero momentum and small frequency (relevant for shear viscosity and hydrodynamic response) in hot, weakly coupled λ ϕ 4 theory. We show that, rather than one or a small number of poles, the correlator has a cut along the negative imaginary frequency axis. We briefly discuss this result's relevance for constructing 2'nd order hydrodynamic models of hot relativistic field theories.

Discrimination between biologically relevant calcium phosphate phases by surface-analytical techniques

NASA Astrophysics Data System (ADS)

Kleine-Boymann, Matthias; Rohnke, Marcus; Henss, Anja; Peppler, Klaus; Sann, Joachim; Janek, Juergen

2014-08-01

The spatially resolved phase identification of biologically relevant calcium phosphate phases (CPPs) in bone tissue is essential for the elucidation of bone remodeling mechanisms and for the diagnosis of bone diseases. Analytical methods with high spatial resolution for the discrimination between chemically quite close phases are rare. Therefore the applicability of state-of-the-art ToF-SIMS, XPS and EDX as chemically specific techniques was investigated. The eight CPPs hydroxyapatite (HAP), β-tricalcium phosphate (β-TCP), α-tricalcium phosphate (α-TCP), octacalcium phosphate (OCP), dicalcium phosphate dihydrate (DCPD), dicalcium phosphate (DCP), monocalcium phosphate (MCP) and amorphous calcium phosphate (ACP) were either commercial materials in high purity or synthesized by ourselves. The phase purity was proven by XRD analysis. All of the eight CPPs show different mass spectra and the phases can be discriminated by applying the principal component analysis method to the mass spectrometric data. The Ca/P ratios of all phosphates were determined by XPS and EDX. With both methods some CPPs can be distinguished, but the obtained Ca/P ratios deviate systematically from their theoretical values. It is necessary in any case to determine a calibration curve, respectively the ZAF values, from appropriate standards. In XPS also the O(1s)-satellite signals are correlated to the CPPs composition. Angle resolved and long-term XPS measurements of HAP clearly prove that there is no phosphate excess at the surface. Decomposition due to X-ray irradiation has not been observed.

Development, scoring, and reliability of the Microscale Audit of Pedestrian Streetscapes (MAPS)

PubMed Central

2013-01-01

Background Streetscape (microscale) features of the built environment can influence people’s perceptions of their neighborhoods’ suitability for physical activity. Many microscale audit tools have been developed, but few have published systematic scoring methods. We present the development, scoring, and reliability of the Microscale Audit of Pedestrian Streetscapes (MAPS) tool and its theoretically-based subscales. Methods MAPS was based on prior instruments and was developed to assess details of streetscapes considered relevant for physical activity. MAPS sections (route, segments, crossings, and cul-de-sacs) were scored by two independent raters for reliability analyses. There were 290 route pairs, 516 segment pairs, 319 crossing pairs, and 53 cul-de-sac pairs in the reliability sample. Individual inter-rater item reliability analyses were computed using Kappa, intra-class correlation coefficient (ICC), and percent agreement. A conceptual framework for subscale creation was developed using theory, expert consensus, and policy relevance. Items were grouped into subscales, and subscales were analyzed for inter-rater reliability at tiered levels of aggregation. Results There were 160 items included in the subscales (out of 201 items total). Of those included in the subscales, 80 items (50.0%) had good/excellent reliability, 41 items (25.6%) had moderate reliability, and 18 items (11.3%) had low reliability, with limited variability in the remaining 21 items (13.1%). Seventeen of the 20 route section subscales, valence (positive/negative) scores, and overall scores (85.0%) demonstrated good/excellent reliability and 3 demonstrated moderate reliability. Of the 16 segment subscales, valence scores, and overall scores, 12 (75.0%) demonstrated good/excellent reliability, three demonstrated moderate reliability, and one demonstrated poor reliability. Of the 8 crossing subscales, valence scores, and overall scores, 6 (75.0%) demonstrated good/excellent reliability, and 2 demonstrated moderate reliability. The cul-de-sac subscale demonstrated good/excellent reliability. Conclusions MAPS items and subscales predominantly demonstrated moderate to excellent reliability. The subscales and scoring system represent a theoretically based framework for using these complex microscale data and may be applicable to other similar instruments. PMID:23621947

The Multivariate Structure of Communication Avoidance.

ERIC Educational Resources Information Center

Bell, Robert A.

1986-01-01

Clarifies the nature of communication avoidance through a structural analysis grounded in facet theory. Presents evidence for a duplex model of avoidance in which theoretical distinctions among modalities of approach-avoidance and context proved empirically relevant. Discusses implications of these findings for the explication, treatment, and…

Four Bootstrap Confidence Intervals for the Binomial-Error Model.

ERIC Educational Resources Information Center

Lin, Miao-Hsiang; Hsiung, Chao A.

1992-01-01

Four bootstrap methods are identified for constructing confidence intervals for the binomial-error model. The extent to which similar results are obtained and the theoretical foundation of each method and its relevance and ranges of modeling the true score uncertainty are discussed. (SLD)

Nuclear Magnetic Resonance Technology for Medical Studies.

ERIC Educational Resources Information Center

Budinger, Thomas F.; Lauterbur, Paul C.

1984-01-01

Reports on the status of nuclear magnetic resonance (NMR) from theoretical and clinical perspectives, reviewing NMR theory and relaxation parameters relevant to NMR imaging. Also reviews literature related to modern imaging strategies, signal-to-noise ratio, contrast agents, in vivo spectroscopy, spectroscopic imaging, clinical applications, and…

Integrating Creativity into Online University Classes

ERIC Educational Resources Information Center

Muirhead, Brent

2007-01-01

In this article, the author provides a concise discussion on creativity, defining the term, sharing theoretical background information and offering insights into promoting creativity in online university classes. Emphasis will be placed on relevant ways to integrate creativity into instructional activities across the academic disciplines. He…

Pacific Educational Research Journal, 2000.

ERIC Educational Resources Information Center

Berg, Kathleen, Ed.; Lai, Morris, Ed.

2000-01-01

This journal features theoretical, empirical, and applied research with implications for and relevance to education in the Pacific area. This volume contains: (1) "Community Perceptions of Culture and Education on Moloka'i" (Lois A. Yamauchi, William L. Greene, Katherine T. Ratliffe, and Andrea K. Ceppi); (2) "Academic Performance…

Review of the Effectiveness of Video Media in Instruction

DTIC Science & Technology

1993-04-01

did beginners . This is consistent with the finding that directing attention to the relevant aspect of the video is more effective, because more...abstract or theoretical concepts with animated flowcharts or diagrams (Riches, 1990). Enhancing Practice. Animation can be used within interactive video and

Theoretical Issues in Clinical Social Group Work.

ERIC Educational Resources Information Center

Randall, Elizabeth; Wodarski, John S.

1989-01-01

Reviews relevant issues in clinical social group practice including group versus individual treatment, group work advantages, approach rationale, group conditions for change, worker role in group, group composition, group practice technique and method, time as group work dimension, pretherapy training, group therapy precautions, and group work…

Simulations and Games as Chaordic Learning Contexts

ERIC Educational Resources Information Center

Leigh, Elyssebeth; Spindler, Laraine

2004-01-01

Effective facilitation of experiential learning involves an array of knowledge and skills. Educators who facilitate open simulations--one form of experiential learning--benefit from having relevant theoretical frameworks to sustain an appropriate balance between being directive and supportive of their participants' freedom to learn. This ongoing…

Natural Codeswitching Knocks on the Laboratory Door

ERIC Educational Resources Information Center

Myers-Scotton, Carol

2006-01-01

This contribution discusses findings and hypotheses from empirical data of naturally-occurring codeswitching. The discussion is framed by some comparisons of the approaches of contact linguists and psycholinguists to bilingual production data. However, it emphasizes the relevance of naturally-occurring codeswitching to the theoretical questions…

It's All in the Mind--Program It for Success.

ERIC Educational Resources Information Center

Jacover, Neal

1980-01-01

A combination of Eastern philosophy and cybernetics leads to a method of improving athletic skills (especially basketball) which is based on the theoretical basis of Maltz's philosophy of successful goal attainment. The method is relevant to the total educational process and to counselors. (SB)

College and Career Readiness in Elementary Schools

ERIC Educational Resources Information Center

Pulliam, Nicole; Bartek, Samantha

2018-01-01

This conceptual article will provide an in-depth exploration of the relevant literature focused on college and career readiness interventions in elementary schools. Beginning with a theoretical framework, a rationale is provided for early intervention by elementary school counselors. While professional guidelines and standards exist supporting…

Spanish Teacher Education Programs and Community Engagement

ERIC Educational Resources Information Center

Jovanovi, Ana; Filipovi, Jelena

2013-01-01

Theories of situated knowledge support that knowledge involves experience of practices rather than just accumulated information. While an important segment of foreign language teacher education programs focuses on the theoretical component of second/foreign language acquisition theories and relevant methodological concerns, it is mainly through…

Simulating Astrophysical Jets with Inertial Confinement Fusion Machines

NASA Astrophysics Data System (ADS)

Blue, Brent

2005-10-01

Large-scale directional outflows of supersonic plasma, also known as `jets', are ubiquitous phenomena in astrophysics. The traditional approach to understanding such phenomena is through theoretical analysis and numerical simulations. However, theoretical analysis might not capture all the relevant physics and numerical simulations have limited resolution and fail to scale correctly in Reynolds number and perhaps other key dimensionless parameters. Recent advances in high energy density physics using large inertial confinement fusion devices now allow controlled laboratory experiments on macroscopic volumes of plasma of direct relevance to astrophysics. This talk will present an overview of these facilities as well as results from current laboratory astrophysics experiments designed to study hydrodynamic jets and Rayleigh-Taylor mixing. This work is performed under the auspices of the U. S. DOE by Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48, Los Alamos National Laboratory under Contract No. W-7405-ENG-36, and the Laboratory for Laser Energetics under Contract No. DE-FC03-92SF19460.

Modeling Supernova Shocks with Intense Lasers.

NASA Astrophysics Data System (ADS)

Blue, Brent

2006-04-01

Large-scale directional outflows of supersonic plasma are ubiquitous phenomena in astrophysics, with specific application to supernovae. The traditional approach to understanding such phenomena is through theoretical analysis and numerical simulations. However, theoretical analysis might not capture all the relevant physics and numerical simulations have limited resolution and fail to scale correctly in Reynolds number and perhaps other key dimensionless parameters. Recent advances in high energy density physics using large inertial confinement fusion devices now allow controlled laboratory experiments on macroscopic volumes of plasma of direct relevance to astrophysics. This talk will present an overview of these facilities as well as results from current laboratory astrophysics experiments designed to study hydrodynamic jets and Rayleigh-Taylor mixing. This work is performed under the auspices of the U. S. DOE by Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48, Los Alamos National Laboratory under Contract No. W-7405-ENG-36, and the Laboratory for Laser Energetics under Contract No. DE-FC03-92SF19460.

Incremental validity of anxiety sensitivity in terms of motivation to quit, reasons for quitting, and barriers to quitting among community-recruited daily smokers.

PubMed

Zvolensky, Michael J; Vujanovic, Anka A; Miller, Marcel O Bonn; Bernstein, Amit; Yartz, Andrew R; Gregor, Kristin L; McLeish, Alison C; Marshall, Erin C; Gibson, Laura E

2007-09-01

The present investigation examined the relationships between anxiety sensitivity and motivation to quit smoking, barriers to smoking cessation, and reasons for quitting smoking among 329 adult daily smokers (160 females; M (age) = 26.08 years, SD = 10.92). As expected, after covarying for the theoretically relevant variables of negative affectivity, gender, Axis I psychopathology, nonclinical panic attack history, number of cigarettes smoked per day, and current levels of alcohol consumption, we found that anxiety sensitivity was significantly incrementally related to level of motivation to quit smoking as well as current barriers to quitting smoking. Partially consistent with the hypotheses, after accounting for the variance explained by other theoretically relevant variables, we found that anxiety sensitivity was significantly associated with self-control reasons for quitting smoking (intrinsic factors) as well as immediate reinforcement and social influence reasons for quitting (extrinsic factors). Results are discussed in relation to better understanding the role of anxiety sensitivity in psychological processes associated with smoking cessation.

Attachment and Chronic Pain in Children and Adolescents

PubMed Central

Donnelly, Theresa J.; Jaaniste, Tiina

2016-01-01

Although attachment theory is not new, its theoretical implications for the pediatric chronic pain context have not been thoroughly considered, and the empirical implications and potential clinical applications are worth exploring. The attachment framework broadly focuses on interactions between a child’s developing self-regulatory systems and their caregiver’s responses. These interactions are believed to create a template for how individuals will relate to others in the future, and may help account for normative and pathological patterns of emotions and behavior throughout life. This review outlines relevant aspects of the attachment framework to the pediatric chronic pain context. The theoretical and empirical literature is reviewed regarding the potential role of attachment-based constructs such as vulnerability and maintaining factors of pediatric chronic pain. The nature and targets of attachment-based pediatric interventions are considered, with particular focus on relevance for the pediatric chronic pain context. The potential role of attachment style in the transition from acute to chronic pain is considered, with further research directions outlined. PMID:27792141

Locality of correlation in density functional theory.

PubMed

Burke, Kieron; Cancio, Antonio; Gould, Tim; Pittalis, Stefano

2016-08-07

The Hohenberg-Kohn density functional was long ago shown to reduce to the Thomas-Fermi (TF) approximation in the non-relativistic semiclassical (or large-Z) limit for all matter, i.e., the kinetic energy becomes local. Exchange also becomes local in this limit. Numerical data on the correlation energy of atoms support the conjecture that this is also true for correlation, but much less relevant to atoms. We illustrate how expansions around a large particle number are equivalent to local density approximations and their strong relevance to density functional approximations. Analyzing highly accurate atomic correlation energies, we show that EC → -AC ZlnZ + BCZ as Z → ∞, where Z is the atomic number, AC is known, and we estimate BC to be about 37 mhartree. The local density approximation yields AC exactly, but a very incorrect value for BC, showing that the local approximation is less relevant for the correlation alone. This limit is a benchmark for the non-empirical construction of density functional approximations. We conjecture that, beyond atoms, the leading correction to the local density approximation in the large-Z limit generally takes this form, but with BC a functional of the TF density for the system. The implications for the construction of approximate density functionals are discussed.

Pedagogy for rural health.

PubMed

Reid, Stephen J

2011-04-01

As the body of literature on rural health has grown, the need to develop a unifying theoretical framework has become more apparent. There are many different ways of seeing the same phenomenon, depending on the assumptions we make and the perspective we choose. A conceptual and theoretical basis for the education of health professionals in rural health has not yet been described. This paper examines a number of theoretical frameworks that have been used in the rural health discourse and aims to identify relevant theory that originates from an educational paradigm. The experience of students in rural health is described phenomenologically in terms of two complementary perspectives, using a geographic basis on the one hand, and a developmental viewpoint on the other. The educational features and implications of these perspectives are drawn out. The concept of a 'pedagogy of place' recognizes the importance of the context of learning and allows the uniqueness of a local community to integrate learning at all levels. The theory of critical pedagogy is also found relevant to education for rural health, which would ideally produce 'transformative' graduates who understand the privilege of their position, and who are capable of and committed to engaging in the struggles for equity and justice, both within their practices as well as in the wider society. It is proposed that a 'critical pedagogy of place,' which gives due acknowledgement to local peculiarities and strengths, while situating this within a wider framework of the political, social and economic disparities that impact on the health of rural people, is an appropriate theoretical basis for a distinct rural pedagogy in the health sciences.

Factors that influence effective perioperative temperature management by anesthesiologists: a qualitative study using the Theoretical Domains Framework.

PubMed

Boet, Sylvain; Patey, Andrea M; Baron, Justine S; Mohamed, Karim; Pigford, Ashlee-Ann E; Bryson, Gregory L; Brehaut, Jamie C; Grimshaw, Jeremy M

2017-06-01

Inadvertent perioperative hypothermia (IPH) is associated with a range of adverse outcomes. Safe and effective warming techniques exist to prevent IPH; however, IPH remains common. This study aimed to identify factors that anesthesiologists perceive may influence temperature management during the perioperative period. After Research Ethics Board approval, semi-structured interviews were conducted with staff anesthesiologists at a Canadian academic hospital. An interview guide based on the Theoretical Domains Framework (TDF) was used to capture 14 theoretical domains that may influence temperature management. The interview transcripts were coded using direct content analysis to generate specific beliefs and to identify relevant TDF domains perceived to influence temperature management behaviour. Data saturation was achieved after 15 interviews. The following nine theoretical domains were identified as relevant to designing an intervention for practices in perioperative temperature management: knowledge, beliefs about capabilities, beliefs about consequences, reinforcement, memory/attention/decision-making, environmental context and resources, social/professional role/identity, social influences, and behavioural regulation. Potential target areas to improve temperature management practices include interventions that address information needs about individual temperature management behaviour as well as patient outcome (feedback), increasing awareness of possible temperature management strategies and guidelines, and a range of equipment and surgical team dynamics that influence temperature management. This study identified several potential target areas for future interventions from nine of the TDF behavioural domains that anesthesiologists perceive to drive their temperature management practices. Future interventions that aim to close the evidence-practice gap in perioperative temperature management may include these targets.

Experimental and theoretical studies on the structural, spectroscopic and hydrogen bonding on 4-nitro-n-(2,4-dinitrophenyl) benzenamine

NASA Astrophysics Data System (ADS)

Subhapriya, G.; Kalyanaraman, S.; Jeyachandran, M.; Ragavendran, V.; Krishnakumar, V.

2018-04-01

Synthesized 4-nitro-N-(2,4-dinitrophenyl) benzenamine (NDPBA) molecule was confirmed applying the tool of NMR. Theoretical prediction addressed the NMR chemical shifts and correlated well with the experimental data. The molecule subjected to theoretical DFT at 6-311++G** level unraveled the spectroscopic and structural properties of the NDPBA molecule. Moreover the structural features proved the occurrence of intramolecular Nsbnd H· · O hydrogen bonding in the molecule which was further confirmed with the help of Frontier molecular orbital analysis. Vibrational spectroscopic characterization through FT-IR and Raman experimentally and theoretically gave an account for the vibrational properties. An illustration of the topology of the molecule theoretically helped also in finding the hydrogen bonding energy.

A theoretical approach to artificial intelligence systems in medicine.

PubMed

Spyropoulos, B; Papagounos, G

1995-10-01

The various theoretical models of disease, the nosology which is accepted by the medical community and the prevalent logic of diagnosis determine both the medical approach as well as the development of the relevant technology including the structure and function of the A.I. systems involved. A.I. systems in medicine, in addition to the specific parameters which enable them to reach a diagnostic and/or therapeutic proposal, entail implicitly theoretical assumptions and socio-cultural attitudes which prejudice the orientation and the final outcome of the procedure. The various models -causal, probabilistic, case-based etc. -are critically examined and their ethical and methodological limitations are brought to light. The lack of a self-consistent theoretical framework in medicine, the multi-faceted character of the human organism as well as the non-explicit nature of the theoretical assumptions involved in A.I. systems restrict them to the role of decision supporting "instruments" rather than regarding them as decision making "devices". This supporting role and, especially, the important function which A.I. systems should have in the structure, the methods and the content of medical education underscore the need of further research in the theoretical aspects and the actual development of such systems.

Word Reading Fluency as a Serial Naming Task

ERIC Educational Resources Information Center

Protopapas, Athanassios; Katopodi, Katerina; Altani, Angeliki; Georgiou, George K.

2018-01-01

Word list reading fluency is theoretically expected to depend on single word reading speed. Yet the correlation between the two diminishes with increasing fluency, while fluency remains strongly correlated to serial digit naming. We hypothesized that multi-element sequence processing is an important component of fluency. We used confirmatory…

The Measurement and Correlates of Career Decision Making.

ERIC Educational Resources Information Center

Harren, Vincent A.; Kass, Richard A.

This paper presents a theoretical framework for understanding career decision making (CDM); introduces an instrument, Assessment of Career Decision Making (ACDM) to measure CDM with college students; and presents correlational data on sex role and cognitive style factors hypothesized to influence CDM. The ACDM, designed to measure the Tiedeman and…

Intelligent diagnosing of intellectual disabilities in offenders: food for thought.

PubMed

Uzieblo, Katarzyna; Winter, Jan; Vanderfaeillie, Johan; Rossi, Gina; Magez, Walter

2012-01-01

Research on offenders with intellectual disabilities (IDs) in the criminal justice arena is on the rise, reflected by a growing number of relevant publications each year. However, there is a long recognized methodological problem that hampers the comparability of empirical studies and that raises doubts about the accuracy of prevalence rates, comorbidities, and various correlates and characteristics. In this paper we will argue that the crux of the problem can, on the one hand, be found in the plurality of assessment methods for intelligence and adaptive functioning, which are not all sufficiently reliable and valid. On the other hand, assessment of IQ in criminal justice and mental health-related areas appears to be informed more by practical aspects and needs rather than grounded in a solid theoretical model. Hence, we suggest that the Cattell-Horn-Carroll (CHC) model of intelligence has potential value in this regard, and deserves a closer look. Finally, we will discuss its incorporation into, and possible implications for, criminal justice practice and future study designs. Copyright © 2012 John Wiley & Sons, Ltd.

The Deceptively Simple N170 Reflects Network Information Processing Mechanisms Involving Visual Feature Coding and Transfer Across Hemispheres.

PubMed

Ince, Robin A A; Jaworska, Katarzyna; Gross, Joachim; Panzeri, Stefano; van Rijsbergen, Nicola J; Rousselet, Guillaume A; Schyns, Philippe G

2016-08-22

A key to understanding visual cognition is to determine "where", "when", and "how" brain responses reflect the processing of the specific visual features that modulate categorization behavior-the "what". The N170 is the earliest Event-Related Potential (ERP) that preferentially responds to faces. Here, we demonstrate that a paradigmatic shift is necessary to interpret the N170 as the product of an information processing network that dynamically codes and transfers face features across hemispheres, rather than as a local stimulus-driven event. Reverse-correlation methods coupled with information-theoretic analyses revealed that visibility of the eyes influences face detection behavior. The N170 initially reflects coding of the behaviorally relevant eye contralateral to the sensor, followed by a causal communication of the other eye from the other hemisphere. These findings demonstrate that the deceptively simple N170 ERP hides a complex network information processing mechanism involving initial coding and subsequent cross-hemispheric transfer of visual features. © The Author 2016. Published by Oxford University Press.

The Impact of Temperatures on the Stability of Rocks Surrounding a Single Fracture

NASA Astrophysics Data System (ADS)

Zhang, Yan; Li, Ning; Dai, Jun

2018-05-01

Research on the influence of temperature and the accompanying stress on the stability of the rocks surrounding an underground tunnel has become ever more important. This paper constructs a geometric model of a single-fracture tunnel by combining a high-temperature underground tunnel as the object of study with an example that uses a high-temperature tunnel segment in the water diversion tunnel of a hydropower station in Xinjiang. Based on the relevant theoretical analysis, with the consideration of different working conditions, a numerical experimental analysis was conducted to determine the two-dimensional transient temperature field distribution of the tunnel rock mass by using a numerical analysis software. The experimental data was consistent with the measured data. The calculated results show the following: a. when the temperature difference is greater, the stress concentration is higher near the fracture of the surrounding rock; b. the degree of the stress concentration in the crack tip region is not positively correlated to the distance, and there is a sensitive region where the stress varies.

Combined Raman and infrared investigation of the insulator-to-metal transition in NiS2-xSex compounds

NASA Astrophysics Data System (ADS)

Marini, C.; Perucchi, A.; Chermisi, D.; Dore, P.; Valentini, M.; Topwal, D.; Sarma, D. D.; Lupi, S.; Postorino, P.

2011-12-01

Ambient-condition Raman spectra were collected in the strongly correlated NiS1-xSex pyrite (0≤x≤1.2). Two samples (x=0 and x=0.55) were studied as a function of pressure up to 10 GPa, and for the x=0.55 sample the pressure dependence of the infrared reflectivity was also measured (0-10 GPa). This gave a complete picture of the optical response of that system on approaching the metallic state both by application of pres-sure and/or by Se alloying, which corresponds to a volume expansion. A peculiar nonmonotonic (V-shaped) volume dependence was found for the quasiparticle spectral weight of both pure and Se-doped compounds. In the x=0.55 sample the vibrational frequencies of the chalcogen dimer show an anomalous volume dependence on entering the metallic phase. The abrupt softening observed, particularly significant for the Se-Se pair, indicates the relevant role of the softness of the Se-Se bond as previously suggested by theoretical calculations.

Spin transport across antiferromagnets induced by the spin Seebeck effect

NASA Astrophysics Data System (ADS)

Cramer, Joel; Ritzmann, Ulrike; Dong, Bo-Wen; Jaiswal, Samridh; Qiu, Zhiyong; Saitoh, Eiji; Nowak, Ulrich; Kläui, Mathias

2018-04-01

For prospective spintronics devices based on the propagation of pure spin currents, antiferromagnets are an interesting class of materials that potentially entail a number of advantages as compared to ferromagnets. Here, we present a detailed theoretical study of magnonic spin current transport in ferromagnetic-antiferromagnetic multilayers by using atomistic spin dynamics simulations. The relevant length scales of magnonic spin transport in antiferromagnets are determined. We demonstrate the transfer of angular momentum from a ferromagnet into an antiferromagnet due to the excitation of only one magnon branch in the antiferromagnet. As an experimental system, we ascertain the transport across an antiferromagnet in Y3Fe5O12 |Ir20Mn80|Pt heterostructures. We determine the spin transport signals for spin currents generated in the Y3Fe5O12 by the spin Seebeck effect and compare to measurements of the spin Hall magnetoresistance in the heterostructure stack. By means of temperature-dependent and thickness-dependent measurements, we deduce conclusions on the spin transport mechanism across Ir20Mn80 and furthermore correlate it to its paramagnetic-antiferromagnetic phase transition.

Psychometric Properties of the Physical Educators' Self-Efficacy Toward Including Students With Disabilities-Autism Among Chinese Preservice Physical Education Teachers.

PubMed

Li, Chunxiao; Wang, Lijuan; Block, Martin E; Sum, Raymond K W; Wu, Yandan

2018-04-01

Teachers' self-efficacy is a critical predictor for successful inclusive physical education. However, little is known about preservice physical educators' self-efficacy toward teaching students with autism spectrum disorders in China. A sound instrument is necessary to measure their self-efficacy level. This validation study examined the psychometric properties of the Chinese version of the Physical Educators' Self-Efficacy Toward Including Students with Disabilities-Autism. A multisection survey form was administered to preservice physical educators in Mainland China (n = 205) and Hong Kong (n = 227). The results of confirmatory factor analysis confirmed the one-factor model of the scale in the total sample and each of the two samples. Invariance tests across the two samples supported configural and metric invariance but not scalar invariance. The scale scores showed good internal reliability and were correlated with theoretically relevant constructs (i.e., burnout and life satisfaction) in the total sample and subsamples. These findings generally support the utility of the scale for use among Chinese preservice physical educators.

Multi-Disciplinary Knowledge Synthesis for Human Health Assessment on Earth and in Space

NASA Astrophysics Data System (ADS)

Christakos, G.

We discuss methodological developments in multi-disciplinary knowledge synthesis (KS) of human health assessment. A theoretical KS framework can provide the rational means for the assimilation of various information bases (general, site-specific etc.) that are relevant to the life system of interest. KS-based techniques produce a realistic representation of the system, provide a rigorous assessment of the uncertainty sources, and generate informative health state predictions across space-time. The underlying epistemic cognition methodology is based on teleologic criteria and stochastic logic principles. The mathematics of KS involves a powerful and versatile spatiotemporal random field model that accounts rigorously for the uncertainty features of the life system and imposes no restriction on the shape of the probability distributions or the form of the predictors. KS theory is instrumental in understanding natural heterogeneities, assessing crucial human exposure correlations and laws of physical change, and explaining toxicokinetic mechanisms and dependencies in a spatiotemporal life system domain. It is hoped that a better understanding of KS fundamentals would generate multi-disciplinary models that are useful for the maintenance of human health on Earth and in Space.

Applied behavior analysis: New directions from the laboratory

PubMed Central

Epling, W. Frank; Pierce, W. David

1983-01-01

Applied behavior analysis began when laboratory based principles were extended to humans inorder to change socially significant behavior. Recent laboratory findings may have applied relevance; however, the majority of basic researchers have not clearly communicated the practical implications of their work. The present paper samples some of the new findings and attempts to demonstrate their applied importance. Schedule-induced behavior which occurs as a by-product of contingencies of reinforcement is discussed. Possible difficulties in treatment and management of induced behaviors are considered. Next, the correlation-based law of effect and the implications of relative reinforcement are explored in terms of applied examples. Relative rate of reinforcement is then extended to the literature dealing with concurrent operants. Concurrent operant models may describe human behavior of applied importance, and several techniques for modification of problem behavior are suggested. As a final concern, the paper discusses several new paradigms. While the practical importance of these models is not clear at the moment, it may be that new practical advantages will soon arise. Thus, it is argued that basic research continues to be of theoretical and practical importance to applied behavior analysis. PMID:22478574

Pixel switching of epitaxial Pd/YHx/CaF2 switchable mirrors

PubMed

Kerssemakers; van der Molen SJ; Koeman; Gunther; Griessen

2000-08-03

Exposure of rare-earth films to hydrogen can induce a metal-insulator transition, accompanied by pronounced optical changes. This 'switchable mirror' effect has received considerable attention from theoretical, experimental and technological points of view. Most systems use polycrystalline films, but the synthesis of yttrium-based epitaxial switchable mirrors has also been reported. The latter form an extended self-organized ridge network during initial hydrogen loading, which results in the creation of micrometre-sized triangular domains. Here we observe homogeneous and essentially independent optical switching of individual domains in epitaxial switchable mirrors during hydrogen absorption. The optical switching is accompanied by topographical changes as the domains sequentially expand and contract; the ridges block lateral hydrogen diffusion and serve as a microscopic lubricant for the domain oscillations. We observe the correlated changes in topology and optical properties using in situ atomic force and optical microscopy. Single-domain phase switching is not observed in polycrystalline films, which are optically homogeneous. The ability to generate a tunable, dense pattern of switchable pixels is of technological relevance for solid-state displays based on switchable mirrors.

Proximity coupling in superconductor-graphene heterostructures.

PubMed

Lee, Gil-Ho; Lee, Hu-Jong

2018-05-01

This review discusses the electronic properties and the prospective research directions of superconductor-graphene heterostructures. The basic electronic properties of graphene are introduced to highlight the unique possibility of combining two seemingly unrelated physics, superconductivity and relativity. We then focus on graphene-based Josephson junctions, one of the most versatile superconducting quantum devices. The various theoretical methods that have been developed to describe graphene Josephson junctions are examined, together with their advantages and limitations, followed by a discussion on the advances in device fabrication and the relevant length scales. The phase-sensitive properties and phase-particle dynamics of graphene Josephson junctions are examined to provide an understanding of the underlying mechanisms of Josephson coupling via graphene. Thereafter, microscopic transport of correlated quasiparticles produced by Andreev reflections at superconducting interfaces and their phase-coherent behaviors are discussed. Quantum phase transitions studied with graphene as an electrostatically tunable 2D platform are reviewed. The interplay between proximity-induced superconductivity and the quantum-Hall phase is discussed as a possible route to study topological superconductivity and non-Abelian physics. Finally, a brief summary on the prospective future research directions is given.

Validation of the Osteoporosis Smoking Health Belief instrument.

PubMed

Doheny, Margaret O; Sedlak, Carol A; Zeller, Richard; Estok, Patricia J

2010-01-01

Smoking has a deleterious effect on bone mineral density. Psychometric properties were conducted for 3 smoking cessation subscales of the Osteoporosis Smoking Health Belief (OSHB) instrument: barriers, benefits, and self-efficacy. The instrument was evaluated by 6 nurse researchers, administered to a pilot sample of 23 adult smokers aged 19-39, and to a convenience sample of 59 adult smokers aged 19-84 years attending bingo at churches and community centers. Principal components factor analyses were conducted on the 18 items at both time points and accounted for 65.05% of the variances in the matrix at Time 1 and 71.19% at Time 2. The 3 statistical factors corresponded to the theoretically derived concepts. Cronbach's alphas for benefits of not smoking were .86 at Time 1 and .88 at Time 2; for barriers, .78 at Time 1 and .89 at Time 2; and for self-efficacy, .94 at Time 1 and .96 at Time 2. The test-retest correlations were .68 for benefits, .74 for barriers, and .79 for self-efficacy. Paired t tests showed no significant change over time. The OSHB meets relevant measurement criteria.

Proximity coupling in superconductor-graphene heterostructures

NASA Astrophysics Data System (ADS)

Lee, Gil-Ho; Lee, Hu-Jong

2018-05-01

This review discusses the electronic properties and the prospective research directions of superconductor-graphene heterostructures. The basic electronic properties of graphene are introduced to highlight the unique possibility of combining two seemingly unrelated physics, superconductivity and relativity. We then focus on graphene-based Josephson junctions, one of the most versatile superconducting quantum devices. The various theoretical methods that have been developed to describe graphene Josephson junctions are examined, together with their advantages and limitations, followed by a discussion on the advances in device fabrication and the relevant length scales. The phase-sensitive properties and phase-particle dynamics of graphene Josephson junctions are examined to provide an understanding of the underlying mechanisms of Josephson coupling via graphene. Thereafter, microscopic transport of correlated quasiparticles produced by Andreev reflections at superconducting interfaces and their phase-coherent behaviors are discussed. Quantum phase transitions studied with graphene as an electrostatically tunable 2D platform are reviewed. The interplay between proximity-induced superconductivity and the quantum-Hall phase is discussed as a possible route to study topological superconductivity and non-Abelian physics. Finally, a brief summary on the prospective future research directions is given.

Toward the Prediction of Water Exchange Rates in Magnetic Resonance Imaging Contrast Agents: A Density Functional Theory Study.

PubMed

Regueiro-Figueroa, Martín; Platas-Iglesias, Carlos

2015-06-18

We present a theoretical investigation of Gd-Owater bonds in different complexes relevant as contrast agents in magnetic resonance imaging (MRI). The analysis of the Ln-Owater distances, electron density (ρBCP), and electron localization function (ELF) at the bond critical points of [Ln(DOTA)(H2O)](-) and [Ln(DTPA-BMA)(H2O)] indicates that the strength of the Ln-Owater bonds follows the order DTPA-BMA > DOTA (M isomer) > DOTA (m isomer). The ELF values decrease along the 4f period as the Ln-Owater bonds get shorter, in line with the labile capping bond phenomenon. Extension of these calculations to other Gd(3+) complexes allowed us to correlate the experimentally observed water exchange rates and the calculated ρBCP and ELF values. The water exchange reaction becomes faster as the Gd-Owater bonds are weakened, which is reflected in longer bond distances and lower values of ρBCP and ELF. DKH2 calculations show that the two coordinated water molecules may also have significantly different (17)O hyperfine coupling constants (HFCCs).

Incorporating Unstructured Socializing Into the Study of Secondary Exposure to Community Violence: Etiological and Empirical Implications.

PubMed

Zimmerman, Gregory M; Messner, Steven F; Rees, Carter

2014-07-01

Secondary exposure to community violence, defined as witnessing or hearing violence in the community, has the potential to profoundly impact long-term development, health, happiness, and security. While research has explored pathways to community violence exposure at the individual, family, and neighborhood levels, prior work has largely neglected situational factors conducive to secondary violence exposure. The present study evaluates "unstructured socializing with peers in the absence of authority figures" as a situational process that has implications for secondary exposure to violence. Results indicate that a measure of unstructured socializing was significantly associated with exposure to violence, net of an array of theoretically relevant covariates of violence exposure. Moreover, the relationships between exposure to violence and three of the most well-established correlates of violence exposure in the literature-age, male, and prior violence-were mediated to varying degrees by unstructured socializing. The results suggest a more nuanced approach to the study of secondary violence exposure that expands the focus of attention beyond individual and neighborhood background factors to include situational opportunities presented by patterns of everyday activities. © The Author(s) 2013.

Event-related potentials in impulsively aggressive juveniles: a retrospective chart-review study.

PubMed

Fisher, William; Ceballos, Natalie; Matthews, Dan; Fisher, Larry

2011-05-30

The assessment, treatment and management of aggressive youth represent a major clinical challenge facing pediatric mental health professionals today. Although a number of studies have examined physiological differences among aggressive patients vs. controls, the current literature lacks a comprehensive examination of the electroencephalographic activity of impulsively aggressive juveniles. The current study was designed to fill this void in the literature via a retrospective chart review of 80 male and female juveniles undergoing inpatient treatment for pathologically impulsive aggression. Clinical reports for mid- and late-latency event-related potentials (ERPs) were examined to determine their correlations with aggression characteristics, as well as any differential predictive utility of hemispheric differences and auditory vs. visual potentials. Results indicated that decrements of mid-latency potentials and ERPs evoked by auditory stimuli (vs. late-latency components and visual ERPs) were more highly predictive of aggressive behavior. No significant hemispheric differences were noted. Taken together, these results have theoretical significance for the etiology of impulsive aggression, and perhaps also clinical relevance for the treatment of this condition. Copyright © 2011 Elsevier Ltd. All rights reserved.

Relapse prevention for addictive behaviors

PubMed Central

2011-01-01

The Relapse Prevention (RP) model has been a mainstay of addictions theory and treatment since its introduction three decades ago. This paper provides an overview and update of RP for addictive behaviors with a focus on developments over the last decade (2000-2010). Major treatment outcome studies and meta-analyses are summarized, as are selected empirical findings relevant to the tenets of the RP model. Notable advances in RP in the last decade include the introduction of a reformulated cognitive-behavioral model of relapse, the application of advanced statistical methods to model relapse in large randomized trials, and the development of mindfulness-based relapse prevention. We also review the emergent literature on genetic correlates of relapse following pharmacological and behavioral treatments. The continued influence of RP is evidenced by its integration in most cognitive-behavioral substance use interventions. However, the tendency to subsume RP within other treatment modalities has posed a barrier to systematic evaluation of the RP model. Overall, RP remains an influential cognitive-behavioral framework that can inform both theoretical and clinical approaches to understanding and facilitating behavior change. PMID:21771314

[Factor analysis and internal consistency of pedagogical practices questionnaire among health care teachers].

PubMed

Pérez V, Cristhian; Vaccarezza G, Giulietta; Aguilar A, César; Coloma N, Katherine; Salgado F, Horacio; Baquedano R, Marjorie; Chavarría R, Carla; Bastías V, Nancy

2016-06-01

Teaching practice is one of the most complex topics of the training process in medicine and other health care careers. The Teaching Practices Questionnaire (TPQ) evaluates teaching skills. To assess the factor structure and internal consistency of the Spanish version of the TPP among health care teachers. The TPQ was answered by 315 university teachers from 13 of the 15 administrative Chilean regions, who were selected through a non-probabilistic volunteer sampling. The internal consistency of TPP factors was calculated and the correlation between them was analyzed. Six factors were identified: Student-centered teaching, Teaching planning, Assessment process, Dialogue relationship, Teacher-centered teaching and Use of technological resources. They had Cronbach alphas ranging from 0.60 to 0.85. The factorial structure of TPQ differentiates the most important functions of teaching. It also shows a theoretical consistency and a practical relevance to perform a diagnosis and continuous evaluation of teaching practices. Additionally, it has an adequate internal consistency. Thus, TPQ is valid and reliable to evaluate pedagogical practices in health care careers.

Experimental-Theoretical Approach to the Adsorption Mechanisms for Anionic, Cationic, and Zwitterionic Surfactants at the Calcite-Water Interface.

PubMed

Durán-Álvarez, Agustín; Maldonado-Domínguez, Mauricio; González-Antonio, Oscar; Durán-Valencia, Cecilia; Romero-Ávila, Margarita; Barragán-Aroche, Fernando; López-Ramírez, Simón

2016-03-22

The adsorption of surfactants (DTAB, SDS, and CAPB) at the calcite-water interface was studied through surface zeta potential measurements and multiscale molecular dynamics. The ground-state polarization of surfactants proved to be a key factor for the observed behavior; correlation was found between adsorption and the hard or soft charge distribution of the amphiphile. SDS exhibits a steep aggregation profile, reaching saturation and showing classic ionic-surfactant behavior. In contrast, DTAB and CAPB featured diversified adsorption profiles, suggesting interplay between supramolecular aggregation and desorption from the solid surface and alleviating charge buildup at the carbonate surface when bulk concentration approaches CMC. This manifests as an adsorption profile with a fast initial step, followed by a metastable plateau and finalizing with a sharp decrease and stabilization of surface charge. Suggesting this competition of equilibria, elicited at the CaCO3 surface, this study provides atomistic insight into the adsorption mechanism for ionic surfactants on calcite, which is in accordance with experimental evidence and which is a relevant criterion for developing enhanced oil recovery processes.

Vibrational Spectroscopy of Ions and Radicals Present in the Interstellar Medium and in Planetary Atmospheres: A Theoretical Study

NASA Technical Reports Server (NTRS)

Chaban, Galina M.

2004-01-01

Anharmonic vibrational frequencies and intensities are calculated for OH(H2O)n and H(H2O)n radicals (that form on icy particles of the interstellar medium), HCO radical (the main intermediate in the synthesis of organic molecules in space), NH2(-) and C2H(-) anions, H5(+) cation, and other systems relevant to interstellar chemistry. In addition to pure ions and radicals, their complexes with water are studied to assess the effects of water environment on infrared spectra. The calculations are performed using the correlation-corrected vibrational self-consistent field (CC-VSCF) method with ab initio potential surfaces at the MP2 and CCSD(T) levels. Fundamental, overtone, and combination excitations are computed. The results are in good agreement with available experimental data and provide reliable predictions for vibrational excitations not yet measured in laboratory experiments. The data should be useful for interpretation of astronomically observed spectra and identification of ions and radicals present in the interstellar medium and in planetary atmospheres.

Adapting the Facilitating Conditions Questionnaire (FCQ) for Bilingual Filipino Adolescents: Validating English and Filipino Versions.

PubMed

Ganotice, Fraide A; Bernardo, Allan B I; King, Ronnel B

2013-06-01

This study examined the applicability of the English and Filipino versions of the Facilitating Conditions Questionnaire (FCQ) among Filipino high school students. The FCQ measures the external forces in students' social environments that can influence their motivation for school. It is composed of 11 factors: university intention, school valuing, parent support, teacher support, peer help, leave school, pride from others, negative parent influence, affect to school, negative peer influence, and positive peer influence. It was translated into conversational Filipino. Seven hundred sixty-five high school students answered one of the two language versions. Both within-network and between-network approaches to construct validation were used. Confirmatory factor analyses (CFA) of the two versions showed good fit. Results of the multigroup CFA indicated that there was invariance in terms of factor loadings for the two versions. Results of the between-network test also showed that the factors in the FCQ correlated systematically with theoretically relevant constructs. Taken together, this study supports the applicability of the FCQ for use with Filipino bilingual adolescents.