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Sample records for activity theory analysis

  1. Transforming Teacher Education, An Activity Theory Analysis

    ERIC Educational Resources Information Center

    McNicholl, Jane; Blake, Allan

    2013-01-01

    This paper explores the work of teacher education in England and Scotland. It seeks to locate this work within conflicting sociocultural views of professional practice and academic work. Drawing on an activity theory framework that integrates the analysis of these seemingly contradictory discourses with a study of teacher educators' practical…

  2. Project-Based Language Learning: An Activity Theory Analysis

    ERIC Educational Resources Information Center

    Gibbes, Marina; Carson, Lorna

    2014-01-01

    This paper reports on an investigation of project-based language learning (PBLL) in a university language programme. Learner reflections of project work were analysed through Activity Theory, where tool-mediated activity is understood as the central unit of analysis for human interaction. Data were categorised according to the components of human…

  3. Transition path theory analysis of c-Src kinase activation.

    PubMed

    Meng, Yilin; Shukla, Diwakar; Pande, Vijay S; Roux, Benoît

    2016-08-16

    Nonreceptor tyrosine kinases of the Src family are large multidomain allosteric proteins that are crucial to cellular signaling pathways. In a previous study, we generated a Markov state model (MSM) to simulate the activation of c-Src catalytic domain, used as a prototypical tyrosine kinase. The long-time kinetics of transition predicted by the MSM was in agreement with experimental observations. In the present study, we apply the framework of transition path theory (TPT) to the previously constructed MSM to characterize the main features of the activation pathway. The analysis indicates that the activating transition, in which the activation loop first opens up followed by an inward rotation of the αC-helix, takes place via a dense set of intermediate microstates distributed within a fairly broad "transition tube" in a multidimensional conformational subspace connecting the two end-point conformations. Multiple microstates with negligible equilibrium probabilities carry a large transition flux associated with the activating transition, which explains why extensive conformational sampling is necessary to accurately determine the kinetics of activation. Our results suggest that the combination of MSM with TPT provides an effective framework to represent conformational transitions in complex biomolecular systems. PMID:27482115

  4. Cultural-Historical Activity Theory and Domain Analysis: Metatheoretical Implications for Information Science

    ERIC Educational Resources Information Center

    Wang, Lin

    2013-01-01

    Background: Cultural-historical activity theory is an important theory in modern psychology. In recent years, it has drawn more attention from related disciplines including information science. Argument: This paper argues that activity theory and domain analysis which uses the theory as one of its bases could bring about some important…

  5. PDAs as Lifelong Learning Tools: An Activity Theory Based Analysis

    ERIC Educational Resources Information Center

    Waycott, Jenny; Jones, Ann; Scanlon, Eileen

    2005-01-01

    This paper describes the use of an activity theory (AT) framework to analyze the ways that distance part time learners and mobile workers adapted and appropriated mobile devices for their activities and in turn how their use of these new tools changed the ways that they carried out their learning or their work. It is argued that there are two key…

  6. Activity Theory and Ontology

    ERIC Educational Resources Information Center

    Peim, Nick

    2009-01-01

    This paper seeks to re-examine Yrio Engestrom's activity theory as a technology of knowledge designed to enable positive transformations of specific practices. The paper focuses on a key paper where Engestrom defines the nature and present state of activity theory. Beginning with a brief account of the relations between activity theory and…

  7. Reflections on Activity Theory

    ERIC Educational Resources Information Center

    Bakhurst, David

    2009-01-01

    It is sometimes suggested that activity theory represents the most important legacy of Soviet philosophy and psychology. But what exactly "is" activity theory? The canonical account in the West is given by Engestrom, who identifies three stages in the theory's development: from Vygotsky's insights, through Leontiev's articulation of the…

  8. Health Behavior Theory in Physical Activity Game Apps: A Content Analysis

    PubMed Central

    Moxley, Victor BA; MacDonald, Elizabeth

    2015-01-01

    Background Physical activity games developed for a mobile phone platform are becoming increasingly popular, yet little is known about their content or inclusion of health behavior theory (HBT). Objective The objective of our study was to quantify elements of HBT in physical activity games developed for mobile phones and to assess the relationship between theoretical constructs and various app features. Methods We conducted an analysis of exercise and physical activity game apps in the Apple App Store in the fall of 2014. A total of 52 apps were identified and rated for inclusion of health behavior theoretical constructs using an established theory-based rubric. Each app was coded for 100 theoretical items, containing 5 questions for 20 different constructs. Possible total theory scores ranged from 0 to 100. Descriptive statistics and Spearman correlations were used to describe the HBT score and association with selected app features, respectively. Results The average HBT score in the sample was 14.98 out of 100. One outlier, SuperBetter, scored higher than the other apps with a score of 76. Goal setting, self-monitoring, and self-reward were the most-reported constructs found in the sample. There was no association between either app price and theory score (P=.5074), or number of gamification elements and theory score (P=.5010). However, Superbetter, with the highest HBT score, was also the most expensive app. Conclusions There are few content analyses of serious games for health, but a comparison between these findings and previous content analyses of non-game health apps indicates that physical activity mobile phone games demonstrate higher levels of behavior theory. The most common theoretical constructs found in this sample are known to be efficacious elements in physical activity interventions. It is unclear, however, whether app designers consciously design physical activity mobile phone games with specific constructs in mind; it may be that games lend

  9. A Case Study Analysis of a Constructionist Knowledge Building Community with Activity Theory

    ERIC Educational Resources Information Center

    Ang, Chee S.; Zaphiris, Panayiotis; Wilson, Stephanie

    2011-01-01

    This article investigates how activity theory can help research a constructionist community. We present a constructionist activity model called CONstructionism Through ACtivity Theory (CONTACT) model and explain how it can be used to analyse the constructionist activity in knowledge building communities. We then illustrate the model through its…

  10. An Application of Activity Theory

    ERIC Educational Resources Information Center

    Marken, James A.

    2006-01-01

    Activity Theory has often been used in workplace settings to gain new theoretical understandings about work and the humans who engage in work, but rarely has there been sufficient detail in the literature to allow HPT practitioners to do their own activity analysis. The detail presented in this case is sufficient for HPT practitioners to begin to…

  11. T-cell activation: A queuing theory analysis at low agonist density.

    PubMed

    Wedagedera, J R; Burroughs, N J

    2006-09-01

    We analyze a simple linear triggering model of the T-cell receptor (TCR) within the framework of queuing theory, in which TCRs enter the queue upon full activation and exit by downregulation. We fit our model to four experimentally characterized threshold activation criteria and analyze their specificity and sensitivity: the initial calcium spike, cytotoxicity, immunological synapse formation, and cytokine secretion. Specificity characteristics improve as the time window for detection increases, saturating for time periods on the timescale of downregulation; thus, the calcium spike (30 s) has low specificity but a sensitivity to single-peptide MHC ligands, while the cytokine threshold (1 h) can distinguish ligands with a 30% variation in the complex lifetime. However, a robustness analysis shows that these properties are degraded when the queue parameters are subject to variation-for example, under stochasticity in the ligand number in the cell-cell interface and population variation in the cellular threshold. A time integration of the queue over a period of hours is shown to be able to control parameter noise efficiently for realistic parameter values when integrated over sufficiently long time periods (hours), the discrimination characteristics being determined by the TCR signal cascade kinetics (a kinetic proofreading scheme). Therefore, through a combination of thresholds and signal integration, a T cell can be responsive to low ligand density and specific to agonist quality. We suggest that multiple threshold mechanisms are employed to establish the conditions for efficient signal integration, i.e., coordinate the formation of a stable contact interface. PMID:16766611

  12. T-Cell Activation: A Queuing Theory Analysis at Low Agonist Density

    PubMed Central

    Wedagedera, J. R.; Burroughs, N. J.

    2006-01-01

    We analyze a simple linear triggering model of the T-cell receptor (TCR) within the framework of queuing theory, in which TCRs enter the queue upon full activation and exit by downregulation. We fit our model to four experimentally characterized threshold activation criteria and analyze their specificity and sensitivity: the initial calcium spike, cytotoxicity, immunological synapse formation, and cytokine secretion. Specificity characteristics improve as the time window for detection increases, saturating for time periods on the timescale of downregulation; thus, the calcium spike (30 s) has low specificity but a sensitivity to single-peptide MHC ligands, while the cytokine threshold (1 h) can distinguish ligands with a 30% variation in the complex lifetime. However, a robustness analysis shows that these properties are degraded when the queue parameters are subject to variation—for example, under stochasticity in the ligand number in the cell-cell interface and population variation in the cellular threshold. A time integration of the queue over a period of hours is shown to be able to control parameter noise efficiently for realistic parameter values when integrated over sufficiently long time periods (hours), the discrimination characteristics being determined by the TCR signal cascade kinetics (a kinetic proofreading scheme). Therefore, through a combination of thresholds and signal integration, a T cell can be responsive to low ligand density and specific to agonist quality. We suggest that multiple threshold mechanisms are employed to establish the conditions for efficient signal integration, i.e., coordinate the formation of a stable contact interface. PMID:16766611

  13. Analysis of the Effect of Water Activity on Ice Formation Using a New Theory of Nucleation

    NASA Technical Reports Server (NTRS)

    Barahona, Donifan

    2013-01-01

    In this work a new theory of nucleation is developed and used to investigate the effect of water activity on the formation of ice within super-cooled droplets. The new theory is based on a novel concept where the interface is assumed to be made of liquid molecules trapped by the solid matrix. Using this concept new expressions are developed for the critical ice germ size and the nucleation work, with explicit dependencies on temperature and water activity. However unlike previous approaches, the new theory does not depend on the interfacial tension between liquid and ice. Comparison against experimental results shows that the new theory is able to reproduce the observed effect of water activity on nucleation rate and freezing temperature. It allows for the first time a theoretical derivation of the constant shift in water activity between melting and nucleation. The new theory offers a consistent thermodynamic view of ice nucleation, simple enough to be applied in atmospheric models of cloud formation.

  14. Technology, Mathematics and Activity Theory

    ERIC Educational Resources Information Center

    Lerman, Stephen

    2013-01-01

    This article describes 11 papers in which the authors report their research on technology as enhancement in the teaching and learning of mathematics, in the context of the application of activity theory for design and/or analysis. There is considerable diversity across the papers in how the authors have interpreted their task and in particular how…

  15. Efficacy of theory-based interventions to promote physical activity. A meta-analysis of randomised controlled trials.

    PubMed

    Gourlan, M; Bernard, P; Bortolon, C; Romain, A J; Lareyre, O; Carayol, M; Ninot, G; Boiché, J

    2016-01-01

    Implementing theory-based interventions is an effective way to influence physical activity (PA) behaviour in the population. This meta-analysis aimed to (1) determine the global effect of theory-based randomised controlled trials dedicated to the promotion of PA among adults, (2) measure the actual efficacy of interventions against their theoretical objectives and (3) compare the efficacy of single- versus combined-theory interventions. A systematic search through databases and review articles was carried out. Our results show that theory-based interventions (k = 82) significantly impact the PA behaviour of participants (d = 0.31, 95% CI [0.24, 0.37]). While moderation analyses revealed no efficacy difference between theories, interventions based on a single theory (d = 0.35; 95% CI [0.26, 0.43]) reported a higher impact on PA behaviour than those based on a combination of theories (d = 0.21; 95% CI [0.11, 0.32]). In spite of the global positive effect of theory-based interventions on PA behaviour, further research is required to better identify the specificities, overlaps or complementarities of the components of interventions based on relevant theories. PMID:25402606

  16. Determinants of physical activity based on the theory of planned behavior in Iranian Military Staff's Wives: a path analysis.

    PubMed

    Gholamnia Shirvani, Zeinab; Ghofranipour, Fazlollah; Gharakhanlou, Reza; Kazemnejad, Anoshirvan

    2015-01-01

    Level of physical activity as a key determinant of healthy lifestyle less than is required in individuals particularly women. Applying theories of behavioral change about complex behaviors such as physical activity leads to identify effective factors and their relations. The aim of this study was to determine predictors of physical activity behavior based on the Theory of Planned Behavior in military staff's wives in Tehran. This cross-sectional study was performed in 180 military personnel's spouses residing in organizational houses, in Tehran, Iran in 2014. The participants were randomly selected with multi-stage cluster sampling. The validity and reliability of the theory based scale evaluated before conducting the path analysis. Statistical analysis was carried out using SPSS16 and LISREL8.8. The results indicated the model explained 77% and 17% of intention and behavior variance. Subjective norms (Beta=0.83) and intention (Beta=0.37) were the strongest predictors of intention and behavior, respectively. The instrumental and affective attitude had no significant path to intention and behavior. The direct relation of perceived behavioral control to behavior was non-significant. This research demonstrated relative importance and relationships of Theory of Planned Behavior constructs in physical activity behavior of military personnel's spouses in Tehran. It is essential to consider these determinants in designing of educational interventions for promoting and maintaining physical activity behavior in this target group. PMID:25948459

  17. Pore size analysis of activated carbons from argon and nitrogen porosimetry using density functional theory

    SciTech Connect

    Dombrowski, R.J.; Hyduke, D.R.; Lastoskie, C.M.

    2000-05-30

    The authors present isotherms calculated from density functional theory for the adsorption of argon in model slit-shaped carbon pores at 77 K. The model isotherms are used to interpret experimental argon uptake measurements and to obtain the pore size distributions of several porous carbons. A similar set of density measurements and to obtain the pore size distributions of several porous carbons. A similar set of density functional theory isotherms, previously reported for nitrogen adsorption on carbon slit pores at 77 K, are used to determine pore size distributions for the same set of carbons. The pore size distribution maxima, mean pore widths, and specific pore volumes measured using the two different probe gases are all found to agree to within approximately 8% on average. Some of the differences in the pore size distributions obtained from argon and nitrogen porosimetry may be attributable to quadrupolar interactions of the nitrogen molecules with functional groups on the carbon surface.

  18. An Activity Theory Analysis of Teaching Goals versus Student Epistemological Positions

    ERIC Educational Resources Information Center

    Jaworski, Barbara; Robinson, Carol; Matthews, Janette; Croft, Tony

    2012-01-01

    A teaching innovation for first year engineering students' was designed to involve inquiry-based questions, an electronic graphical medium, small group activity and modifications to assessment. The use of an inquiry approach was intended to encourage students' deeper engagement with mathematics and more conceptual understanding. Data were…

  19. An Analysis of Spanish L2 Learners' Orientation through Activity Theory

    ERIC Educational Resources Information Center

    Tocaimaza-Hatch, C. Cecilia

    2015-01-01

    Orientation is defined as the way in which individuals view a task and the means they devise to fulfill it (Appel & Lantolf, 1994; Roebuck, 2000). This study investigated the orientation of twelve learners enrolled in a fourth-semester Spanish L2 university course through the analysis of their interactions during a collaborative…

  20. Integrating Social Activity Theory and Critical Discourse Analysis: A Multilayered Methodological Model for Examining Knowledge Mediation in Mentoring

    ERIC Educational Resources Information Center

    Becher, Ayelet; Orland-Barak, Lily

    2016-01-01

    This study suggests an integrative qualitative methodological framework for capturing complexity in mentoring activity. Specifically, the model examines how historical developments of a discipline direct mentors' mediation of professional knowledge through the language that they use. The model integrates social activity theory and a framework of…

  1. Program Theory Evaluation: Logic Analysis

    ERIC Educational Resources Information Center

    Brousselle, Astrid; Champagne, Francois

    2011-01-01

    Program theory evaluation, which has grown in use over the past 10 years, assesses whether a program is designed in such a way that it can achieve its intended outcomes. This article describes a particular type of program theory evaluation--logic analysis--that allows us to test the plausibility of a program's theory using scientific knowledge.…

  2. Activation analysis

    SciTech Connect

    Alfassi, Z.B. . Dept. of Nuclear Engineering)

    1990-01-01

    This volume contains 16 chapters on the application of activation analysis in the fields of life sciences, biological materials, coal and its effluents, environmental samples, archaeology, material science, and forensics. Each chapter is processed separately for the data base.

  3. Concerning interpretations of activity theory.

    PubMed

    Mironenko, Irina A

    2013-09-01

    Activity theory (AT) is the most recognised part of Russian psychology outside Russia. However the general view of AT in international science is rather unilateral, lacking substantial aspects and areas necessary for proper understanding. This article is aimed at expanding the image of AT dominant in the mainstream which reduces the AT trend to A.N. Leontiev's theory. This reduction impoverishes the creative potentialities of the trend, and decreases the ability of AT to contribute to international science. We aim to reveal that AT is not limited to Leontiev's approach, to explain which ideas of the founders of AT, S.L. Rubinstein and L.S. Vygotsky, were pursued and which were rejected by A.N. Leontiev, and to assess another important contribution to the AT trend - the theory of B.G. Ananiev, where the ideas of AT's founders were developed which were not succeeded by A.N. Leontiev. Historical causes and consequences of the general reduction of the image of AT in the mainstream to Leontiev's theory are considered: why the discrepancies between views of Rubinstein, Vygotsky and Leontiev were hardly ever discussed in public and why other theories contemporary to Leontiev's theory were never given account appropriate to their value in Russia and remain almost unknown abroad. PMID:23512520

  4. Sociocultural Dynamics of ESL Learning (De)Motivation: An Activity Theory Analysis of Two Adult Korean Immigrants

    ERIC Educational Resources Information Center

    Kim, Tae-Young

    2011-01-01

    This study examines the longitudinal trajectories of two Korean ESL immigrants' L2 learning motivation from an Activity Theory perspective. Two highly skilled immigrants participated in monthly semistructured interviews over a period of 10 months. The research questions are as follows: (1) How does the relationship between ESL learners and their…

  5. Applied PhD Research in a Work-Based Environment: An Activity Theory-Based Analysis

    ERIC Educational Resources Information Center

    Granata, S. N.; Dochy, F.

    2016-01-01

    Activity theory is used to compare PhD undertaken at university, that is, academic PhD, with PhD performed in collaboration with industry, that is, semi-industrial PhD. The research is divided into a literature review and a case study. Semi-industrial and academic PhD are modelled as activity systems, and differences are highlighted in terms of…

  6. Io. [theories concerning volcanic activity

    NASA Technical Reports Server (NTRS)

    Johnson, T. V.; Soderblom, L. A.

    1983-01-01

    A report on the continuing investigation of Io is presented. Gravitational resonance is discussed as the cause of Io's volcanism, and the volcanic activity is explained in terms of sulfur chemistry. Theories concerning the reasons for the two main types of volcanic eruptions on Io are advanced and correlated with geographical features of the satellite. The sulfur and silicate models of the calderas are presented, citing the strengths and weaknesses of each. Problems of the gravitational resonance theory of Io's heat source are then described. Finally, observations of Io planned for the Galileo mission are summarized.

  7. Determinants of Physical Activity Based on the Theory of Planned Behavior in Iranian Military Staff’s Wives: A Path Analysis

    PubMed Central

    Shirvani, Zeinab Gholamnia; Ghofranipour, Fazlollah; Gharakhanlou, Reza; Kazemnejad, Anoshirvan

    2015-01-01

    Level of physical activity as a key determinant of healthy lifestyle less than is required in individuals particularly women. Applying theories of behavioral change about complex behaviors such as physical activity leads to identify effective factors and their relations. The aim of this study was to determine predictors of physical activity behavior based on the Theory of Planned Behavior in military staff’s wives in Tehran. This cross-sectional study was performed in 180 military personnel’s spouses residing in organizational houses, in Tehran, Iran in 2014. The participants were randomly selected with multi-stage cluster sampling. The validity and reliability of the theory based scale evaluated before conducting the path analysis. Statistical analysis was carried out using SPSS16 and LISREL8.8. The results indicated the model explained 77% and 17% of intention and behavior variance. Subjective norms (Beta=0.83) and intention (Beta=0.37) were the strongest predictors of intention and behavior, respectively. The instrumental and affective attitude had no significant path to intention and behavior. The direct relation of perceived behavioral control to behavior was non-significant. This research demonstrated relative importance and relationships of Theory of Planned Behavior constructs in physical activity behavior of military personnel’s spouses in Tehran. It is essential to consider these determinants in designing of educational interventions for promoting and maintaining physical activity behavior in this target group. PMID:25948459

  8. Multi-Level Discourse Analysis in a Physics Teaching Methods Course from the Psychological Perspective of Activity Theory

    ERIC Educational Resources Information Center

    Vieira, Rodrigo Drumond; Kelly, Gregory J.

    2014-01-01

    In this paper, we present and apply a multi-level method for discourse analysis in science classrooms. This method is based on the structure of human activity (activity, actions, and operations) and it was applied to study a pre-service physics teacher methods course. We argue that such an approach, based on a cultural psychological perspective,…

  9. Multi-level Discourse Analysis in a Physics Teaching Methods Course from the Psychological Perspective of Activity Theory

    NASA Astrophysics Data System (ADS)

    Drumond Vieira, Rodrigo; Kelly, Gregory J.

    2014-11-01

    In this paper, we present and apply a multi-level method for discourse analysis in science classrooms. This method is based on the structure of human activity (activity, actions, and operations) and it was applied to study a pre-service physics teacher methods course. We argue that such an approach, based on a cultural psychological perspective, affords opportunities for analysts to perform a theoretically based detailed analysis of discourse events. Along with the presentation of analysis, we show and discuss how the articulation of different levels offers interpretative criteria for analyzing instructional conversations. We synthesize the results into a model for a teacher's practice and discuss the implications and possibilities of this approach for the field of discourse analysis in science classrooms. Finally, we reflect on how the development of teachers' understanding of their activity structures can contribute to forms of progressive discourse of science education.

  10. Theory of active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Shields, G. A.

    1986-01-01

    The involvement of accretion disks around supermassive black holes in the theory of active galactic nuclei (AGN) is discussed. The physics of thin and thick accretion disks is discussed and the partition between thermal and nonthermal energy production in supermassive disks is seen as uncertain. The thermal limit cycle may operate in supermassive disks (Shields, 1985), with accumulation of gas in the disk for periods of 10 to the 4th to 10 to the 7th years, punctuated by briefer outbursts during which the mass is rapidly transferred to smaller radii. An extended X-ray source in AGN is consistent with observations (Tennant and Mushotsky, 1983), and a large wind mass loss rate exceeding the central accretion rate means that only a fraction of the mass entering the disk will reach the central object; the rest being lost to the wind. Controversy in the relationship between the broad lines and the disk is also discussed.

  11. A Framework for Theory Analysis

    ERIC Educational Resources Information Center

    Duffey, Margery; Muhlenkamp, Ann F.

    1974-01-01

    The paper examines two theories in nursing--those of Peplau and Rogers. The works of these two theorists were selected because they illustrate variation in approach. The origin of the problems, the methods, the character of the subject matter, and the expected outcomes of testing are the four questions used in the analysis. (MW)

  12. Dynamical mean-field theory and weakly non-linear analysis for the phase separation of active Brownian particles

    SciTech Connect

    Speck, Thomas; Menzel, Andreas M.; Bialké, Julian; Löwen, Hartmut

    2015-06-14

    Recently, we have derived an effective Cahn-Hilliard equation for the phase separation dynamics of active Brownian particles by performing a weakly non-linear analysis of the effective hydrodynamic equations for density and polarization [Speck et al., Phys. Rev. Lett. 112, 218304 (2014)]. Here, we develop and explore this strategy in more detail and show explicitly how to get to such a large-scale, mean-field description starting from the microscopic dynamics. The effective free energy emerging from this approach has the form of a conventional Ginzburg-Landau function. On the coarsest scale, our results thus agree with the mapping of active phase separation onto that of passive fluids with attractive interactions through a global effective free energy (motility-induced phase transition). Particular attention is paid to the square-gradient term necessary for the phase separation kinetics. We finally discuss results from numerical simulations corroborating the analytical results.

  13. How do interprofessional student teams interact in a primary care clinic? A qualitative analysis using activity theory.

    PubMed

    Kent, Fiona; Francis-Cracknell, Alison; McDonald, Rachael; Newton, Jennifer M; Keating, Jennifer L; Dodic, Miodrag

    2016-10-01

    Practice based interprofessional education opportunities are proposed as a mechanism for health professionals to learn teamwork skills and gain an understanding of the roles of others. Primary care is an area of practice that offers a promising option for interprofessional student learning. In this study, we investigated what and how students from differing professions learn together. Our findings inform the design of future interprofessional education initiatives. Using activity theory, we conducted an ethnographic investigation of interprofessional education in primary care. During a 5 months period, we observed 14 clinic sessions involving mixed discipline student teams who interviewed people with chronic disease. Teams were comprised of senior medicine, nursing, occupational therapy, pharmacy and physiotherapy entry level students. Semi-structured interviews were also conducted with seven clinical educators. Data were analysed to ascertain the objectives, tools, rules and division of labour. Two integrated activity systems were identified: (1) student teams gathering information to determine patients' health care needs and (2) patients either as health consumers or student educators. Unwritten rules regarding 'shared contribution', 'patient as key information source' and 'time constraints' were identified. Both the significance of software literacy on team leadership, and a pre-determined structure of enquiry, highlighted the importance of careful consideration of the tools used in interprofessional education, and the way they can influence practice. The systems of practice identified provide evidence of differing priorities and values, and multiple perspectives of how to manage health. The work reinforced the value of the patients' voice in clinical and education processes. PMID:26781698

  14. Pedagogical Distance: Explaining Misalignment in Student-Driven Online Learning Activities Using Activity Theory

    ERIC Educational Resources Information Center

    Westberry, Nicola; Franken, Margaret

    2015-01-01

    This paper provides an Activity Theory analysis of two online student-driven interactive learning activities to interrogate assumptions that such groups can effectively learn in the absence of the teacher. Such an analysis conceptualises learning tasks as constructed objects that drive pedagogical activity. The analysis shows a disconnect between…

  15. [Application of the rough sets theory to the analysis of structure-activity relationships of pyridinium antifungal compounds].

    PubMed

    Krysiński, J

    1994-04-01

    Relationships between chemical structure and antifungal activity of 72 quaternary pyridinium chlorides were analysed using the method of rough sets. In the information system the compounds are described by eight condition attributes and divided into three classes of activity. Using the rough sets approach a smallest set of four condition attributes significant for a high quality of classification and accuracy of classes has been found. The resulting decision algorithm describes relations between structure and antifungal activity in terms of significant condition attributes. It may be helpful in predicting structures of new antifungal compounds to be synthesized. PMID:8204024

  16. Pattern activation/recognition theory of mind

    PubMed Central

    du Castel, Bertrand

    2015-01-01

    In his 2012 book How to Create a Mind, Ray Kurzweil defines a “Pattern Recognition Theory of Mind” that states that the brain uses millions of pattern recognizers, plus modules to check, organize, and augment them. In this article, I further the theory to go beyond pattern recognition and include also pattern activation, thus encompassing both sensory and motor functions. In addition, I treat checking, organizing, and augmentation as patterns of patterns instead of separate modules, therefore handling them the same as patterns in general. Henceforth I put forward a unified theory I call “Pattern Activation/Recognition Theory of Mind.” While the original theory was based on hierarchical hidden Markov models, this evolution is based on their precursor: stochastic grammars. I demonstrate that a class of self-describing stochastic grammars allows for unifying pattern activation, recognition, organization, consistency checking, metaphor, and learning, into a single theory that expresses patterns throughout. I have implemented the model as a probabilistic programming language specialized in activation/recognition grammatical and neural operations. I use this prototype to compute and present diagrams for each stochastic grammar and corresponding neural circuit. I then discuss the theory as it relates to artificial network developments, common coding, neural reuse, and unity of mind, concluding by proposing potential paths to validation. PMID:26236228

  17. Pattern activation/recognition theory of mind.

    PubMed

    du Castel, Bertrand

    2015-01-01

    In his 2012 book How to Create a Mind, Ray Kurzweil defines a "Pattern Recognition Theory of Mind" that states that the brain uses millions of pattern recognizers, plus modules to check, organize, and augment them. In this article, I further the theory to go beyond pattern recognition and include also pattern activation, thus encompassing both sensory and motor functions. In addition, I treat checking, organizing, and augmentation as patterns of patterns instead of separate modules, therefore handling them the same as patterns in general. Henceforth I put forward a unified theory I call "Pattern Activation/Recognition Theory of Mind." While the original theory was based on hierarchical hidden Markov models, this evolution is based on their precursor: stochastic grammars. I demonstrate that a class of self-describing stochastic grammars allows for unifying pattern activation, recognition, organization, consistency checking, metaphor, and learning, into a single theory that expresses patterns throughout. I have implemented the model as a probabilistic programming language specialized in activation/recognition grammatical and neural operations. I use this prototype to compute and present diagrams for each stochastic grammar and corresponding neural circuit. I then discuss the theory as it relates to artificial network developments, common coding, neural reuse, and unity of mind, concluding by proposing potential paths to validation. PMID:26236228

  18. A psychometric investigation of the Hypersexual Disorder Screening Inventory among highly sexually active gay and bisexual men: An item response theory analysis

    PubMed Central

    Parsons, Jeffrey T.; Rendina, H. Jonathon; Ventuneac, Ana; Cook, Karon F.; Grov, Christian; Mustanski, Brian

    2013-01-01

    Introduction The Hypersexual Disorder Screening Inventory (HDSI) was designed as an instrument for the screening of hypersexuality by the American Psychiatric Association’s DSM-5 taskforce. Aim Our study sought to conduct a psychometric analysis of the HDSI, including an investigation of its underlying structure and reliability utilizing Item Response Theory (IRT) modeling, and an examination of its polythetic scoring criteria in comparison to a standard dimensionally-based cutoff score. Methods We examined a diverse group of 202 highly sexually active gay and bisexual men in New York City. We conducted psychometric analyses of the HDSI, including both confirmatory factor analysis of its structure and item response theory analysis of the item and scale reliabilities. Main Outcome Measures We utilized the Hypersexual Disorder Screening Inventory. Results The HDSI adequately fit a single-factor solution, although there was evidence that two of the items may measure a second factor that taps into sex as a form of coping. The scale showed evidence of strong reliability across much of the continuum of hypersexuality and results suggested that, in addition to the proposed polythetic scoring criteria, a cutoff score of 20 on the severity index might be used for preliminary classification of HD. Conclusion The HDSI was found to be highly reliable and results suggested that a unidimensional, quantitative conception of hypersexuality with a clinically relevant cutoff score may be more appropriate than a qualitative syndrome comprised of multiple distinct clusters of problems. However, we also found preliminary evidence that three clusters of symptoms may constitute an HD syndrome as opposed to the two clusters initially proposed. Future research is needed to determine which of these issues are characteristic of the hypersexuality and HD constructs themselves and which are more likely to be methodological artifacts of the HDSI. PMID:23534845

  19. Understanding Change in Teachers' Ways of Being through Collaborative Action Research: A Cultural-Historical Activity Theory Analysis

    ERIC Educational Resources Information Center

    Feldman, Allan; Weiss, Tarin

    2010-01-01

    Despite major efforts to change teachers' practice through professional development activities, much remains as it always was. Our claim is that this rarely happens because significant change in how one teaches can only come about as a result of some realization about oneself as a teacher, and the resulting changes in identity. In recent years we…

  20. Inverse modelling of Köhler theory - Part 1: A response surface analysis of CCN spectra with respect to surface-active organic species

    NASA Astrophysics Data System (ADS)

    Lowe, Samuel; Partridge, Daniel; Topping, David; Stier, Philip

    2016-04-01

    In this study an inverse modelling framework for the calculation of CCN spectra is developed to facilitate a more robust treatment of evaluation of Köhler models against observations. To achieve this, we define an objective function that provides a diagnostic metric of the deviation of modelled CCN spectra from observations as a function of input parameters. This allows for the assessment of model accuracy while simultaneously examining global parameter sensitivities and identifying parameter interactions across all atmospherically relevant supersaturations, corresponding to a broad range of cloud types and updraft velocities. The focus of this study is two-fold. Firstly, we assess the feasibility of inverse modelling as a new methodology for aerosol-CCN spectra closure. To achieve this goal, responses in the objective function to parameter perturbations in 2D cross-sections of the complete parameter space, response surfaces, are used to examine the likelihood of our chosen objective function containing enough information to constrain the model input parameters considered using automatic search algorithms. Secondly, these response surfaces are employed to conduct an extensive parametric sensitivity analysis and subsequently rank the relative importance of aerosol physiochemical parameters in determining CCN spectra. Using Köhler theory to model CCN concentrations requires knowledge of many physiochemical parameters, some of which are difficult to measure in-situ at the scale of interest. Therefore, novel methodologies, such as the one developed here, are required to probe the entire parameter space of aerosol-cloud interaction problems and provide global sensitivity analyses to constrain parametric uncertainties. Partitioning of surface-active species from the bulk to the surface phase can alter the point of CCN activation. Therefore, the analysis conducted here is carried out for a standard Köhler model as well as more complex Köhler models accounting for the

  1. Activity Theory and Language Teacher Agency

    ERIC Educational Resources Information Center

    Feryok, Anne

    2012-01-01

    This article takes a broadly sociocultural perspective on the development of an Armenian English as a foreign language (EFL) teacher. It focuses on how experiences and actions outside the professional development classroom influence language teacher agency. The paper is framed within activity theory and specifically draws on Galperin's orienting…

  2. Cultural Historical Activity Theory and Professional Learning

    ERIC Educational Resources Information Center

    Daniels, Harry

    2004-01-01

    In this article I will discuss the route by which I came to work with Cultural Historical Activity Theory (CHAT). The brief tracing of my own biography will highlight theoretical and methodological milestones. I will then discuss my current work, with colleagues, on approaches to investigating and improving the learning of professionals who are…

  3. Linking Complexity with Cultural Historical Activity Theory

    ERIC Educational Resources Information Center

    McMurtry, Angus

    2006-01-01

    This paper explores the similarities and differences between complexity science's and cultural-historical activity theory's understandings of human learning. Notable similarities include their emphasis on the importance of social systems or collectives in understanding human knowledge and practices, as well as their characterization of systems'…

  4. Using activity theory to study cultural complexity in medical education.

    PubMed

    Frambach, Janneke M; Driessen, Erik W; van der Vleuten, Cees P M

    2014-06-01

    There is a growing need for research on culture, cultural differences and cultural effects of globalization in medical education, but these are complex phenomena to investigate. Socio-cultural activity theory seems a useful framework to study cultural complexity, because it matches current views on culture as a dynamic process situated in a social context, and has been valued in diverse fields for yielding rich understandings of complex issues and key factors involved. This paper explains how activity theory can be used in (cross-)cultural medical education research. We discuss activity theory's theoretical background and principles, and we show how these can be applied to the cultural research practice by discussing the steps involved in a cross-cultural study that we conducted, from formulating research questions to drawing conclusions. We describe how the activity system, the unit of analysis in activity theory, can serve as an organizing principle to grasp cultural complexity. We end with reflections on the theoretical and practical use of activity theory for cultural research and note that it is not a shortcut to capture cultural complexity: it is a challenge for researchers to determine the boundaries of their study and to analyze and interpret the dynamics of the activity system. PMID:24590549

  5. Videogames, Tools for Change: A Study Based on Activity Theory

    ERIC Educational Resources Information Center

    Méndez, Laura; Lacasa, Pilar

    2015-01-01

    Introduction: The purpose of this study is to provide a framework for analysis from which to interpret the transformations that take place, as perceived by the participants, when commercial video games are used in the classroom. We will show how Activity Theory (AT) is able to explain and interpret these changes. Method: Case studies are…

  6. Dynamo theory prediction of solar activity

    NASA Technical Reports Server (NTRS)

    Schatten, Kenneth H.

    1988-01-01

    The dynamo theory technique to predict decadal time scale solar activity variations is introduced. The technique was developed following puzzling correlations involved with geomagnetic precursors of solar activity. Based upon this, a dynamo theory method was developed to predict solar activity. The method was used successfully in solar cycle 21 by Schatten, Scherrer, Svalgaard, and Wilcox, after testing with 8 prior solar cycles. Schatten and Sofia used the technique to predict an exceptionally large cycle, peaking early (in 1990) with a sunspot value near 170, likely the second largest on record. Sunspot numbers are increasing, suggesting that: (1) a large cycle is developing, and (2) that the cycle may even surpass the largest cycle (19). A Sporer Butterfly method shows that the cycle can now be expected to peak in the latter half of 1989, consistent with an amplitude comparable to the value predicted near the last solar minimum.

  7. Analyzing Activities in the Course of Science Education, According to Activity Theory: The Case of Sound

    ERIC Educational Resources Information Center

    Theodoraki, Xarikleia; Plakitsi, Katerina

    2013-01-01

    In the present study, we analyze activities on the topic of sound, which are performed in the science education laboratory lessons in the third-year students of the Department of Early Childhood Education at the University of Ioannina. The analysis of the activities is based on one of the most modern learning theories of CHAT (Cultural Historical…

  8. Flutter analysis using transversality theory

    NASA Technical Reports Server (NTRS)

    Afolabi, D.

    1993-01-01

    A new method of calculating flutter boundaries of undamped aeronautical structures is presented. The method is an application of the weak transversality theorem used in catastrophe theory. In the first instance, the flutter problem is cast in matrix form using a frequency domain method, leading to an eigenvalue matrix. The characteristic polynomial resulting from this matrix usually has a smooth dependence on the system's parameters. As these parameters change with operating conditions, certain critical values are reached at which flutter sets in. Our approach is to use the transversality theorem in locating such flutter boundaries using this criterion: at a flutter boundary, the characteristic polynomial does not intersect the axis of the abscissa transversally. Formulas for computing the flutter boundaries and flutter frequencies of structures with two degrees of freedom are presented, and extension to multi-degree of freedom systems is indicated. The formulas have obvious applications in, for instance, problems of panel flutter at supersonic Mach numbers.

  9. One Pot Selective Arylation of 2-Bromo-5-Chloro Thiophene; Molecular Structure Investigation via Density Functional Theory (DFT), X-ray Analysis, and Their Biological Activities

    PubMed Central

    Rasool, Nasir; Kanwal, Aqsa; Rasheed, Tehmina; Ain, Quratulain; Mahmood, Tariq; Ayub, Khurshid; Zubair, Muhammad; Khan, Khalid Mohammed; Arshad, Muhammad Nadeem; M. Asiri, Abdullah; Zia-Ul-Haq, Muhammad; Jaafar, Hawa Z. E.

    2016-01-01

    Synthesis of 2,5-bisarylthiophenes was accomplished by sequential Suzuki cross coupling reaction of 2-bromo-5-chloro thiophenes. Density functional theory (DFT) studies were carried out at the B3LYP/6-31G(d, p) level of theory to compare the geometric parameters of 2,5-bisarylthiophenes with those from X-ray diffraction results. The synthesized compounds are screened for in vitro bacteria scavenging abilities. At the concentration of 50 and 100 μg/mL, compounds 2b, 2c, 2d, 3c, and 3f with IC50-values of 51.4, 52.10, 58.0, 56.2, and 56.5 μg/mL respectively, were found most potent against E. coli. Among all the synthesized compounds 2a, 2d, 3c, and 3e with the least values of IC50 77, 76.26, 79.13 μg/mL respectively showed significant antioxidant activities. Almost all of the compounds showed good antibacterial activity against Escherichia coli, whereas 2-chloro-5-(4-methoxyphenyl) thiophene (2b) was found most active among all synthesized compound with an IC50 value of 51.4 μg/mL. All of the synthesized compounds were screened for nitric oxide scavenging activity as well. Frontier molecular orbitals (FMOs) and molecular electrostatic potentials of the target compounds were also studied theoretically to account for their relative reactivity PMID:27367666

  10. One Pot Selective Arylation of 2-Bromo-5-Chloro Thiophene; Molecular Structure Investigation via Density Functional Theory (DFT), X-ray Analysis, and Their Biological Activities.

    PubMed

    Rasool, Nasir; Kanwal, Aqsa; Rasheed, Tehmina; Ain, Quratulain; Mahmood, Tariq; Ayub, Khurshid; Zubair, Muhammad; Khan, Khalid Mohammed; Arshad, Muhammad Nadeem; M Asiri, Abdullah; Zia-Ul-Haq, Muhammad; Jaafar, Hawa Z E

    2016-01-01

    Synthesis of 2,5-bisarylthiophenes was accomplished by sequential Suzuki cross coupling reaction of 2-bromo-5-chloro thiophenes. Density functional theory (DFT) studies were carried out at the B3LYP/6-31G(d, p) level of theory to compare the geometric parameters of 2,5-bisarylthiophenes with those from X-ray diffraction results. The synthesized compounds are screened for in vitro bacteria scavenging abilities. At the concentration of 50 and 100 μg/mL, compounds 2b, 2c, 2d, 3c, and 3f with IC50-values of 51.4, 52.10, 58.0, 56.2, and 56.5 μg/mL respectively, were found most potent against E. coli. Among all the synthesized compounds 2a, 2d, 3c, and 3e with the least values of IC50 77, 76.26, 79.13 μg/mL respectively showed significant antioxidant activities. Almost all of the compounds showed good antibacterial activity against Escherichia coli, whereas 2-chloro-5-(4-methoxyphenyl) thiophene (2b) was found most active among all synthesized compound with an IC50 value of 51.4 μg/mL. All of the synthesized compounds were screened for nitric oxide scavenging activity as well. Frontier molecular orbitals (FMOs) and molecular electrostatic potentials of the target compounds were also studied theoretically to account for their relative reactivity. PMID:27367666

  11. Aerodynamic preliminary analysis system. Part 1: Theory. [linearized potential theory

    NASA Technical Reports Server (NTRS)

    Bonner, E.; Clever, W.; Dunn, K.

    1978-01-01

    A comprehensive aerodynamic analysis program based on linearized potential theory is described. The solution treats thickness and attitude problems at subsonic and supersonic speeds. Three dimensional configurations with or without jet flaps having multiple non-planar surfaces of arbitrary planform and open or closed slender bodies of non-circular contour may be analyzed. Longitudinal and lateral-directional static and rotary derivative solutions may be generated. The analysis was implemented on a time sharing system in conjunction with an input tablet digitizer and an interactive graphics input/output display and editing terminal to maximize its responsiveness to the preliminary analysis problem. Nominal case computation time of 45 CPU seconds on the CDC 175 for a 200 panel simulation indicates the program provides an efficient analysis for systematically performing various aerodynamic configuration tradeoff and evaluation studies.

  12. The Systemic-Structural Theory of Activity: Applications to the Study of Human Work

    ERIC Educational Resources Information Center

    Bedny, Gregory Z.; Harris, Steven Robert

    2005-01-01

    This article offers an introduction to the central concepts and principles of the Systemic-Structural Theory of Activity (SSTA), an activity-theoretical approach specifically tailored to the analysis and design of human work. In activity theory, cognition is understood both as a process and as a structured system of actions. Building on the…

  13. Evolutionary Game Theory Analysis of Tumor Progression

    NASA Astrophysics Data System (ADS)

    Wu, Amy; Liao, David; Sturm, James; Austin, Robert

    2014-03-01

    Evolutionary game theory applied to two interacting cell populations can yield quantitative prediction of the future densities of the two cell populations based on the initial interaction terms. We will discuss how in a complex ecology that evolutionary game theory successfully predicts the future densities of strains of stromal and cancer cells (multiple myeloma), and discuss the possible clinical use of such analysis for predicting cancer progression. Supported by the National Science Foundation and the National Cancer Institute.

  14. Modeling active memory: Experiment, theory and simulation

    NASA Astrophysics Data System (ADS)

    Amit, Daniel J.

    2001-06-01

    Neuro-physiological experiments on cognitively performing primates are described to argue that strong evidence exists for localized, non-ergodic (stimulus specific) attractor dynamics in the cortex. The specific phenomena are delay activity distributions-enhanced spike-rate distributions resulting from training, which we associate with working memory. The anatomy of the relevant cortex region and the physiological characteristics of the participating elements (neural cells) are reviewed to provide a substrate for modeling the observed phenomena. Modeling is based on the properties of the integrate-and-fire neural element in presence of an input current of Gaussian distribution. Theory of stochastic processes provides an expression for the spike emission rate as a function of the mean and the variance of the current distribution. Mean-field theory is then based on the assumption that spike emission processes in different neurons in the network are independent, and hence the input current to a neuron is Gaussian. Consequently, the dynamics of the interacting network is reduced to the computation of the mean and the variance of the current received by a cell of a given population in terms of the constitutive parameters of the network and the emission rates of the neurons in the different populations. Within this logic we analyze the stationary states of an unstructured network, corresponding to spontaneous activity, and show that it can be stable only if locally the net input current of a neuron is inhibitory. This is then tested against simulations and it is found that agreement is excellent down to great detail. A confirmation of the independence hypothesis. On top of stable spontaneous activity, keeping all parameters fixed, training is described by (Hebbian) modification of synapses between neurons responsive to a stimulus and other neurons in the module-synapses are potentiated between two excited neurons and depressed between an excited and a quiescent neuron

  15. Rethinking Distance Learning Activities: A Comparison of Transactional Distance Theory and Activity Theory

    ERIC Educational Resources Information Center

    Kang, Haijun; Gyorke, Allan S.

    2008-01-01

    Despite its invaluable guidance to distance education development, transactional distance (TD) theory is not seamlessly synchronised with current field practice and lacks a social component. After it has provided over 30 years of guidance, there is now a need to re-appraise TD's propositions about distance learning activities. The social-cultural…

  16. Theory and modeling of active brazing.

    SciTech Connect

    van Swol, Frank B.; Miller, James Edward; Lechman, Jeremy B.; Givler, Richard C.

    2013-09-01

    Active brazes have been used for many years to produce bonds between metal and ceramic objects. By including a relatively small of a reactive additive to the braze one seeks to improve the wetting and spreading behavior of the braze. The additive modifies the substrate, either by a chemical surface reaction or possibly by alloying. By its nature, the joining process with active brazes is a complex nonequilibrium non-steady state process that couples chemical reaction, reactant and product diffusion to the rheology and wetting behavior of the braze. Most of the these subprocesses are taking place in the interfacial region, most are difficult to access by experiment. To improve the control over the brazing process, one requires a better understanding of the melting of the active braze, rate of the chemical reaction, reactant and product diffusion rates, nonequilibrium composition-dependent surface tension as well as the viscosity. This report identifies ways in which modeling and theory can assist in improving our understanding.

  17. Comparing Educational Tools Using Activity Theory: Clickers and Flashcards

    NASA Astrophysics Data System (ADS)

    Price, Edward; De Leone, Charles; Lasry, Nathaniel

    2010-10-01

    Physics educators and researchers have recently begun to distinguish between pedagogical approaches and the educational technologies that are used to implement them. For instance, peer instruction has been shown to be equally effective, in terms of student learning outcomes, when implemented with clickers or flashcards. Therefore, technological tools (clickers and flashcards) can be viewed as means to mediate pedagogical techniques (peer instruction or traditional instruction). In this paper, we use activity theory to examine peer instruction, with particular attention to the role of tools. This perspective helps clarify clickers' and flashcards' differences, similarities, impacts in the classroom, and utility to education researchers. Our analysis can suggest improvements and new uses. Finally, we propose activity theory as a useful approach in understanding and improving the use of technology in the physics classroom.

  18. An Introduction to Wavelet Theory and Analysis

    SciTech Connect

    Miner, N.E.

    1998-10-01

    This report reviews the history, theory and mathematics of wavelet analysis. Examination of the Fourier Transform and Short-time Fourier Transform methods provides tiormation about the evolution of the wavelet analysis technique. This overview is intended to provide readers with a basic understanding of wavelet analysis, define common wavelet terminology and describe wavelet amdysis algorithms. The most common algorithms for performing efficient, discrete wavelet transforms for signal analysis and inverse discrete wavelet transforms for signal reconstruction are presented. This report is intended to be approachable by non- mathematicians, although a basic understanding of engineering mathematics is necessary.

  19. Structure in Teaching Theory and Analysis.

    ERIC Educational Resources Information Center

    Anderson, O. Roger

    A theory of structure in teaching is presented and a system of analysis introduced which allows empirical investigation of verbal behavior in the classroom. Two kinds of structure are distinguished: "static" structure, defined as stable organized clusters of knowledge, and "kinetic" structure, defined as the sequential process of building up…

  20. Theory and Application of DNA Histogram Analysis.

    ERIC Educational Resources Information Center

    Bagwell, Charles Bruce

    The underlying principles and assumptions associated with DNA histograms are discussed along with the characteristics of fluorescent probes. Information theory was described and used to calculate the information content of a DNA histogram. Two major types of DNA histogram analyses are proposed: parametric and nonparametric analysis. Three levels…

  1. Bloom's Theory of School Learning: An Analysis.

    ERIC Educational Resources Information Center

    Marjoribanks, Kevin

    1980-01-01

    An analysis of associations among children's intelligence, personality, perceptions of school environment, attitudes toward school, and self-concept is reported. The study used Bloom's theory of school learning which examines relationships among student characteristics, quality of instruction, and children's learning outcomes. (Author/KC)

  2. Activity Theory as a Framework For Designing Constructivist Learning Environments.

    ERIC Educational Resources Information Center

    Jonassen, David H.; Rohrer-Murphy, Lucia

    1999-01-01

    Defines activity theory as a socio-cultural and socio-historical lens through which the interaction of human activity and consciousness within its relevant environmental context can be analyzed. Describes how activity theory can be used as a framework for analyzing activities and settings for the purpose of designing constructivist learning…

  3. Divisions of Labour: Activity Theory, Multi-Professional Working and Intervention Research

    ERIC Educational Resources Information Center

    Warmington, Paul

    2011-01-01

    This article draws upon, but also critiques, activity theory by combining analysis of how an activity theory derived research intervention attempted to address both everyday work practices and organisational power relationships among children's services professionals. It offers two case studies of developmental work research (DWR) interventions in…

  4. Rhetorical structure theory and text analysis

    NASA Astrophysics Data System (ADS)

    Mann, William C.; Matthiessen, Christian M. I. M.; Thompson, Sandra A.

    1989-11-01

    Recent research on text generation has shown that there is a need for stronger linguistic theories that tell in detail how texts communicate. The prevailing theories are very difficult to compare, and it is also very difficult to see how they might be combined into stronger theories. To make comparison and combination a bit more approachable, we have created a book which is designed to encourage comparison. A dozen different authors or teams, all experienced in discourse research, are given exactly the same text to analyze. The text is an appeal for money by a lobbying organization in Washington, DC. It informs, stimulates and manipulates the reader in a fascinating way. The joint analysis is far more insightful than any one team's analysis alone. This paper is our contribution to the book. Rhetorical Structure Theory (RST), the focus of this paper, is a way to account for the functional potential of text, its capacity to achieve the purposes of speakers and produce effects in hearers. It also shows a way to distinguish coherent texts from incoherent ones, and identifies consequences of text structure.

  5. Activity Theory and Higher Education: Evaluating Learning Technologies

    ERIC Educational Resources Information Center

    Scanlon, E.; Issroff, K.

    2005-01-01

    This paper examines current practice in the evaluation of learning technology in the UK and proposes a new approach informed by Activity Theory. It is based on our experiences of using Activity Theory to understand students' and lecturers' experiences of technology-based teaching environments. We discuss the activity of evaluating learning…

  6. Theory and technology in behavior analysis 1

    PubMed Central

    Hayes, Steven C.

    1978-01-01

    The differences within behaviorism in general and behavior analysis in particular have been described in many ways. Some of the more common distinctions are “basic versus applied”, “clinical versus non-clinical”, “behavior therapy versus behavior analysis”, and “experimental analysis of behavior versus applied behavior analysis”. These and other such distinctions do not seem to refer to truely important differences, or refer to important differences in confusing ways. It is suggested that there are two main dimensions which divide behaviorists into meaningful units: the type of paradigm (behavior analysis versus methodological behaviorism) and the level of analysis (technical, methodological, conceptual, or philosophical). By considering these two dimensions a number of issues in the field are recast. In particular, many of the differences within behavior analysis are recast into questions of the relationship between theory and technology. PMID:22477953

  7. Density Functional Theory Analysis of Structure, Energetics, and Spectroscopy for the Mn-Fe Active Site of Chlamydia trachomatis Ribonucleotide Reductase in Four Oxidation States

    PubMed Central

    Han, Wen-Ge; Giammona, Debra Ann; Bashford, Donald; Noodleman, Louis

    2010-01-01

    Models for the Mn-Fe active site structure of ribonucleotide reductase (RNR) from pathogenic bacteria Chlamydia trachomatis (Ct) in different oxidation states have been studied in this paper, using broken-symmetry density functional theory (DFT) incorporated with the conductor like screening (COSMO) solvation model and also with the finite-difference Poisson-Boltzmann self-consistent reaction field (PB-SCRF) calculations. The detailed structures for the reduced Mn(II)-Fe(II), the met Mn(III)-Fe(III), the oxidized Mn(IV)-Fe(III) and the superoxidized Mn(IV)-Fe(IV) states are predicted. The calculated properties, including geometries, 57Fe Mössbauer isomer shifts and quadrupole splittings, and 57Fe and 55Mn ENDOR hyperfine coupling constants, are compared with the available experimental data. The Mössbauer and energetic calculations show that the (μ-oxo, μ-hydroxo) models better represent the structure of the Mn(IV)-Fe(III) state than the di-μ-oxo models. The predicted Mn(IV)-Fe(III) distances (2.95 and 2.98 Å) in the (μ-oxo, μ-hydroxo) models are in agreement with the EXAFS experimental value of 2.92 Å (Younker, et al. J. Am. Chem. Soc. 2008, 130, 15022-15027). The effect of the protein and solvent environment on the assignment of the Mn metal position is examined by comparing the relative energies of alternative mono-Mn(II) active site structures. It is proposed that if the Mn(II)-Fe(II) protein is prepared with prior addition of Mn(II) or with Mn(II) richer than Fe(II), Mn is likely positioned at metal site 2, which is further from Phe127. PMID:20604534

  8. Activity Theory and Situated Learning Theory: Contrasting Views of Educational Practice

    ERIC Educational Resources Information Center

    Arnseth, Hans Christian

    2008-01-01

    The purpose of this article is to offer a critical discussion of the practice turn in contemporary educational research. In order to make the discussion specific, I use two influential theories, namely activity theory and situated learning theory. They both turn to the notion of practice in order to overcome the limitations of mentalist and…

  9. Applications of Ergodic Theory to Coverage Analysis

    NASA Technical Reports Server (NTRS)

    Lo, Martin W.

    2003-01-01

    The study of differential equations, or dynamical systems in general, has two fundamentally different approaches. We are most familiar with the construction of solutions to differential equations. Another approach is to study the statistical behavior of the solutions. Ergodic Theory is one of the most developed methods to study the statistical behavior of the solutions of differential equations. In the theory of satellite orbits, the statistical behavior of the orbits is used to produce 'Coverage Analysis' or how often a spacecraft is in view of a site on the ground. In this paper, we consider the use of Ergodic Theory for Coverage Analysis. This allows us to greatly simplify the computation of quantities such as the total time for which a ground station can see a satellite without ever integrating the trajectory, see Lo 1,2. More over, for any quantity which is an integrable function of the ground track, its average may be computed similarly without the integration of the trajectory. For example, the data rate for a simple telecom system is a function of the distance between the satellite and the ground station. We show that such a function may be averaged using the Ergodic Theorem.

  10. Astrophysical data analysis with information field theory

    SciTech Connect

    Enßlin, Torsten

    2014-12-05

    Non-parametric imaging and data analysis in astrophysics and cosmology can be addressed by information field theory (IFT), a means of Bayesian, data based inference on spatially distributed signal fields. IFT is a statistical field theory, which permits the construction of optimal signal recovery algorithms. It exploits spatial correlations of the signal fields even for nonlinear and non-Gaussian signal inference problems. The alleviation of a perception threshold for recovering signals of unknown correlation structure by using IFT will be discussed in particular as well as a novel improvement on instrumental self-calibration schemes. IFT can be applied to many areas. Here, applications in in cosmology (cosmic microwave background, large-scale structure) and astrophysics (galactic magnetism, radio interferometry) are presented.

  11. Composite box beam analysis - Theory and experiments

    NASA Technical Reports Server (NTRS)

    Bauchau, O. A.; Coffenberry, B. S.; Rehfield, L. W.

    1987-01-01

    Beam theory is widely used as a first approximation in numerous structural applications. When applied to composite beams, the accuracy of beam theory becomes questionable because (1) the shearing and warping deformations become significant, as the shearing stiffness of composite laminates is often very low, and (2) several elastic couplings can occur that strongly influence the behavior of composite beams. The torsional behavior of thin-walled composite beams has important implications for aeronautical structures and is deeply modified by the above nonclassical effects. This paper presents two comprehensive analysis methodologies for composite beams and describes experimental results obtained from a thin-walled, rectangular cross-sectional beam. The theoretical predictions are found in good agreement with the observed twist and strain distributions. Out-of-plane torsional warping of the cross-section is found to be the key factor for an accurate modeling of the torsional behavior of such structures.

  12. Community Service-Learning and Cultural-Historical Activity Theory

    ERIC Educational Resources Information Center

    Taylor, Alison

    2014-01-01

    This paper explores the potential of cultural-historical activity theory (CHAT), to provide new insights into community service-learning (CSL) in higher education. While CSL literature acknowledges the influences of John Dewey and Paolo Freire, discussion of the potential contribution of cultural-historical activity theory, rooted in the work of…

  13. A Guided Inquiry Activity for Teaching Ligand Field Theory

    ERIC Educational Resources Information Center

    Johnson, Brian J.; Graham, Kate J.

    2015-01-01

    This paper will describe a guided inquiry activity for teaching ligand field theory. Previous research suggests the guided inquiry approach is highly effective for student learning. This activity familiarizes students with the key concepts of molecular orbital theory applied to coordination complexes. Students will learn to identify factors that…

  14. Teaching Sociological Theory through Active Learning: The Irrigation Exercise

    ERIC Educational Resources Information Center

    Holtzman, Mellisa

    2005-01-01

    For students, theory is often one of the most daunting aspects of sociology--it seems abstract, removed from the concrete events of their everyday lives, and therefore intimidating. In an attempt to break down student resistance to theory, instructors are increasingly turning to active learning approaches. Active learning exercises, then, appear…

  15. Laboratory theory and methods for sediment analysis

    USGS Publications Warehouse

    Guy, Harold P.

    1969-01-01

    The diverse character of fluvial sediments makes the choice of laboratory analysis somewhat arbitrary and the pressing of sediment samples difficult. This report presents some theories and methods used by the Water Resources Division for analysis of fluvial sediments to determine the concentration of suspended-sediment samples and the particle-size distribution of both suspended-sediment and bed-material samples. Other analyses related to these determinations may include particle shape, mineral content, and specific gravity, the organic matter and dissolved solids of samples, and the specific weight of soils. The merits and techniques of both the evaporation and filtration methods for concentration analysis are discussed. Methods used for particle-size analysis of suspended-sediment samples may include the sieve pipet, the VA tube-pipet, or the BW tube-VA tube depending on the equipment available, the concentration and approximate size of sediment in the sample, and the settling medium used. The choice of method for most bed-material samples is usually limited to procedures suitable for sand or to some type of visual analysis for large sizes. Several tested forms are presented to help insure a well-ordered system in the laboratory to handle the samples, to help determine the kind of analysis required for each, to conduct the required processes, and to assist in the required computations. Use of the manual should further 'standardize' methods of fluvial sediment analysis among the many laboratories and thereby help to achieve uniformity and precision of the data.

  16. The process of theory analysis: an examination of the nursing theory of Dorothea E. Orem.

    PubMed

    Melnyk, K A

    1983-01-01

    The process of theory analysis is undertaken examining the nursing theory of Dorothea E. Orem on three levels, using the analytic framework devised by Barbara J. Stevens. The commonplaces of the theory are described, the elements and principles are identified, the internal construction is examined, and the theory as a whole is then evaluated in terms of its relationship to modern nursing. PMID:6551778

  17. Critical Curriculum Theory and Slow Ecopedagogical Activism

    ERIC Educational Resources Information Center

    Payne, Phillip G.

    2015-01-01

    Enacting a critical environmental education curriculum theory with 8- to 9-year-old children in 1978 is now "restoried" in a "history of the present/future" like "case study" for prosecuting five interrelated problems confronting progress in environmental education and its research. They are: the intense heat of the…

  18. [I. P. Pavlov's theory on higher nervous activity: the landmarks and trends in its development].

    PubMed

    Chilingarian, L I

    1999-01-01

    The theory of higher nervous activity created in Pavlovian time is compared with the present-day state of the theory developing due to appearance of new methods, techniques, facts, and concepts. Three principles of Pavlovian theory: determinism; analysis and synthesis; structural approach, as well s types of conditioned reflexes and techniques, types of higher nervous activity, and inhibition problems are discussed. The theory of higher nervous activity is schematically depicted as a tree, some branches of which are presented by facts and concepts obtained and introduced by I.P. Pavlov and his followers during his life, the others are formed by new facts and concepts advancing the theory. What is obsolete in the theory, what are the most prominent tendencies of its development and its new branches are discussed. PMID:10693269

  19. An Activity Theory Approach to Analyze Barriers to a Virtual Management Information Systems (MIS) Curriculum

    ERIC Educational Resources Information Center

    Jaradat, Suhair; Qablan, Ahmad; Barham, Areej

    2011-01-01

    This paper explains how the activity theory is used as a framework to analyze the barriers to a virtual Management Information Stream (MIS) Curriculum in Jordanian schools, from both the sociocultural and pedagogical perspectives. Taking the activity system as a unit of analysis, this study documents the processes by which activities shape and are…

  20. A Comparative Analysis of Three Unique Theories of Organizational Learning

    ERIC Educational Resources Information Center

    Leavitt, Carol C.

    2011-01-01

    The purpose of this paper is to present three classical theories on organizational learning and conduct a comparative analysis that highlights their strengths, similarities, and differences. Two of the theories -- experiential learning theory and adaptive -- generative learning theory -- represent the thinking of the cognitive perspective, while…

  1. Object relations theory and activity theory: a proposed link by way of the procedural sequence model.

    PubMed

    Ryle, A

    1991-12-01

    An account of object relations theory (ORT), represented in terms of the procedural sequence model (PSM), is compared to the ideas of Vygotsky and activity theory (AT). The two models are seen to be compatible and complementary and their combination offers a satisfactory account of human psychology, appropriate for the understanding and integration of psychotherapy. PMID:1786224

  2. Neutron activation analysis system

    DOEpatents

    Taylor, M.C.; Rhodes, J.R.

    1973-12-25

    A neutron activation analysis system for monitoring a generally fluid media, such as slurries, solutions, and fluidized powders, including two separate conduit loops for circulating fluid samples within the range of radiation sources and detectors is described. Associated with the first loop is a neutron source that emits s high flux of slow and thermal neutrons. The second loop employs a fast neutron source, the flux from which is substantially free of thermal neutrons. Adjacent to both loops are gamma counters for spectrographic determination of the fluid constituents. Other gsmma sources and detectors are arranged across a portion of each loop for deterMining the fluid density. (Official Gazette)

  3. Multicomponent dynamical nucleation theory and sensitivity analysis.

    PubMed

    Kathmann, Shawn M; Schenter, Gregory K; Garrett, Bruce C

    2004-05-15

    Vapor to liquid multicomponent nucleation is a dynamical process governed by a delicate interplay between condensation and evaporation. Since the population of the vapor phase is dominated by monomers at reasonable supersaturations, the formation of clusters is governed by monomer association and dissociation reactions. Although there is no intrinsic barrier in the interaction potential along the minimum energy path for the association process, the formation of a cluster is impeded by a free energy barrier. Dynamical nucleation theory provides a framework in which equilibrium evaporation rate constants can be calculated and the corresponding condensation rate constants determined from detailed balance. The nucleation rate can then be obtained by solving the kinetic equations. The rate constants governing the multistep kinetics of multicomponent nucleation including sensitivity analysis and the potential influence of contaminants will be presented and discussed. PMID:15267849

  4. Refined methods of aeroelastic analysis and optimization. [swept wings, propeller theory, and subsonic flutter

    NASA Technical Reports Server (NTRS)

    Ashley, H.

    1984-01-01

    Graduate research activity in the following areas is reported: the divergence of laminated composite lifting surfaces, subsonic propeller theory and aeroelastic analysis, and cross sectional resonances in wind tunnels.

  5. Singularity analysis: theory and further developments

    NASA Astrophysics Data System (ADS)

    Cheng, Qiuming

    2015-04-01

    Since the concept of singularity and local singularity analysis method (LSA) were originally proposed by the author for characterizing the nonlinear property of hydrothermal mineralization processes, the local singularity analysis technique has been successfully applied for identification of geochemical and geophysical anomalies related to various types of mineral deposits. It has also been shown that the singularity is the generic property of singular geo-processes which result in anomalous amounts of energy release or material accumulation within a narrow spatial-temporal interval. In the current paper we introduce several new developments about singularity analysis. First is a new concept of 'fractal density' which describes the singularity of complex phenomena of fractal nature. While the ordinary density possesses a unit of ratio of mass and volume (e.g. g/cm3, kg/m3) or ratio of energy over volume or time (e.g. J/cm3, w/L3, w/s), the fractal density has a unit of ratio of mass over fractal set or energy over fractal set (e.g. g/cmα, kg/mα, J/ mα, w/Lα, where α can be a non-integer). For the matter with fractal density (a non-integer α), the ordinary density of the phenomena (mass or energy) no longer exists and depicts singularity. We demonstrate that most of extreme geo-processes occurred in the earth crust originated from cascade earth dynamics (mental convection, plate tectonics, orogeny and weathering etc) may cause fractal density of mass accumulation or energy release. The examples to be used to demonstrate the concepts of fractal density and singularity are earthquakes, floods, volcanos, hurricanes, heat flow over oceanic ridge, hydrothermal mineralization in orogenic belt, and anomalies in regolith over mine caused by ore and toxic elements vertical migration. Other developments of singularity theory and methodologies including singular Kriging and singularity weights of evidence model for information integration will also be introduced.

  6. From Social Motives to Spiritual Development: A Cultural Historical Activity Theory Analysis of Communal Spiritual Development in a Korean American House Church

    ERIC Educational Resources Information Center

    Park, SinWoong Simon

    2013-01-01

    This study focused on a unique culturally shaped church formation, a Korean house church in the U.S., and how the members of the Korean house church learn and develop their spirituality in their communal relations and activities. (Abstract shortened by UMI.) [The dissertation citations contained here are published with the permission of ProQuest…

  7. Understanding Tensions: Activity Systems Analysis of Cross-Continental Collaboration

    ERIC Educational Resources Information Center

    Ryder, LanHui Zhang; Yamagata-Lynch, Lisa

    2014-01-01

    Using the lens of Vygotsky's sociocultural theory, activity theory, and Engeström's activity systems analysis, this qualitative study explores students' experiences in the context of a sixteen-week transpacific collaboration between seven students at Northern Illinois University (NIU) and seven students from Shandong Normal…

  8. [Behavioral Activation for Depression: Theory and Practice].

    PubMed

    Nakao, Tomohiro

    2015-01-01

    Behavioral activation (BA) has recently attracted marked attention. While cognitive therapy focuses on the cognitive distortion of patients with depression and asks them to change their behaviors as the process of altering the cognitive distortion, BA pays attention to behavior to avoid an unpleasant situation or social situation as a key symptom that leads to persistence of the depression. Avoidance behaviors are often seen during every process of depression, from onset to recurrence. Avoidance behaviors, a decrease in pleasant phenomena, or increase in unpleasant phenomena, result in reinforcing a depressive mood. If patients can set appropriate behavioral targets and achieve them, the beneficial behaviors will be further promoted with positive feed-back. The behavioral change, as-a consequence, will result in improvement of the mood, cognition, and depression itself. In this manuscript, the author presents two clinical cases, in which BA assisted the patients in recovering from their depression. The first case was a male in his thirties who repeatedly took sick leave from his work because of maladjustment, which resulted in persistent depression. The second case was a female in her thirties who suffered from OCD and then became maladjusted to her place of work, depressive, and emotionally unstable. In both cases, avoidant behaviors caused their conditions to persist. Appropriate activities formed by BA improved their moods, and their self-efficacies were gradually regained. It was suggested that BA is markedly effective, especially in patients whose avoidant behaviors mainly cause the persistence of their depressive symptoms. PMID:26514042

  9. Self-Efficacy Theory and the Theory of Planned Behavior: Teaching Physically Active Physical Education Classes

    ERIC Educational Resources Information Center

    Martin, Jeffrey J.; Kulinna, Pamela Hodges

    2004-01-01

    The purpose of this investigation was to examine determinants of teachers' intentions to teach physically active physical education classes (i.e., spend at least 50% of class time with the students engaged in moderate to vigorous physical activity). Based on the theory of planned behavior, a model was examined hypothesizing that teachers'…

  10. Analysis of Theoretical Metaphors with Illustrations from Family Systems Theory.

    ERIC Educational Resources Information Center

    Rosenblatt, Paul C.

    Metaphoric analysis of family systems theory illustrates how metaphors and alternatives to those metaphors identify what a psychological theory has highlighted and obscured about the phenomena at its focus and how it has structured that phenomena. The most commonly used metaphors in family systems theory are the metaphors of system (system…

  11. Studying Doctoral Education: Using Activity Theory to Shape Methodological Tools

    ERIC Educational Resources Information Center

    Beauchamp, Catherine; Jazvac-Martek, Marian; McAlpine, Lynn

    2009-01-01

    The study reported here, one part of a larger study on doctoral education, describes a pilot study that used Activity Theory to shape a methodological tool for better understanding the tensions inherent in the doctoral experience. As doctoral students may function within a range of activity systems, we designed data collection protocols based on…

  12. Narratives and Activity Theory as Reflective Tools in Action Research

    ERIC Educational Resources Information Center

    Stuart, Kaz

    2012-01-01

    Narratives and activity theory are useful as socially constructed data collection tools that allow a researcher access to the social, cultural and historical meanings that research participants place on events in their lives. This case study shows how these tools were used to promote reflection within a cultural-historical activity theoretically…

  13. Transformation or Transformism: Engestrom's Version of Activity Theory?

    ERIC Educational Resources Information Center

    Avis, James

    2009-01-01

    The paper examines Engestrom's version of activity theory. It seeks to locate this within the socio-economic and theoretical context in which notions of co-configuration and knotworking are set. Although this theoretical approach offers radical possibilities it is limited by its neglect of the wider social context in which activity systems are…

  14. Nonlinear constitutive theory for turbine engine structural analysis

    NASA Technical Reports Server (NTRS)

    Thompson, R. L.

    1982-01-01

    A number of viscoplastic constitutive theories and a conventional constitutive theory are evaluated and compared in their ability to predict nonlinear stress-strain behavior in gas turbine engine components at elevated temperatures. Specific application of these theories is directed towards the structural analysis of combustor liners undergoing transient, cyclic, thermomechanical load histories. The combustor liner material considered in this study is Hastelloy X. The material constants for each of the theories (as a function of temperature) are obtained from existing, published experimental data. The viscoplastic theories and a conventional theory are incorporated into a general purpose, nonlinear, finite element computer program. Several numerical examples of combustor liner structural analysis using these theories are given to demonstrate their capabilities. Based on the numerical stress-strain results, the theories are evaluated and compared.

  15. The Theory and Practice of Active Aging

    PubMed Central

    Fries, James F.

    2012-01-01

    Active aging” connotes a radically nontraditional paradigm of aging which posits possible improvement in health despite increasing longevity. The new paradigm is based upon postponing functional declines more than mortality declines and compressing morbidity into a shorter period later in life. This paradigm (Compression of Morbidity) contrasts with the old, where increasing longevity inevitably leads to increasing morbidity. We have focused our research on controlled longitudinal studies of aging. The Runners and Community Controls study began at age 58 in 1984 and the Health Risk Cohorts study at age 70 in 1986. We noted that disability was postponed by 14 to 16 years in vigorous exercisers compared with controls and postponed by 10 years in low-risk cohorts compared with higher risk. Mortality was also postponed, but too few persons had died for valid comparison of mortality and morbidity. With the new data presented here, age at death at 30% mortality is postponed by 7 years in Runners and age at death at 50% (median) mortality by 3.3 years compared to controls. Postponement of disability is more than double that of mortality in both studies. These differences increase over time, occur in all subgroups, and persist after statistical adjustment. PMID:23118746

  16. Comparative analysis of Orem's and King's theories.

    PubMed

    Hanucharurnkul, S

    1989-05-01

    Dorothea Orem and Imogene King are two nursing theorists who are contributing significantly to the development of nursing knowledge. This paper compares the similarities and differences in their strategies for theory development, their views of nursing metaparadigm concepts, and their theories of nursing system and goal attainment in terms of scope, usefulness, and their unique contribution to nursing science. PMID:2738232

  17. Platinum-Mediated Activation of Coordinated Organonitriles by Telluroethers in Tetrahydrofuran: Isolation, Structural Characterization, and Density Functional Theory Analysis of Intermediate Complexes.

    PubMed

    Kolay, Siddhartha; Wadawale, Amey; Nigam, Sandeep; Kumar, Mukesh; Majumder, Chiranjib; Das, Dasarathi; Jain, Vimal K

    2015-12-21

    The reactions of [PtCl2(NCR)2] with telluroethers (ArAr'Te) in organic solvents have been investigated. The reactions in dichloromethane yield [PtCl2(TeArAr')2], while those in tetrahydrofuran (THF) give different products depending on the steric demands of the aryl groups on tellurium, the molarity of the reactants, and the reaction conditions. The reactions between [PtCl2(PhCN)2] and TeArAr' in 1:1 molar ratio at room temperature in THF yield several products, like [PtCl2(TeArAr')2] (Ar/Ar' = Ph/Ph, o-tol/Mes, Mes/Mes), [PtCl2(PhCN){NC(O)Ph[TeMes(o-tol)]}], and [PtCl2{NC(O)Ph(TeMes2)}2]. The reaction with TeMes2 in refluxing THF gave [PtCl2{NC(Ph)C4H7O}{NC(O)Ph(TeMes2)}] and [PtCl(TeMes2){Te(Mes)CH2C6H2Me2}], depending on the duration of heating. Reaction of [PtCl2(PhCN)2] with TeArMes afforded [PtCl2(TeArMes)2] (Ar = Ph, o-tol, and Mes), the formation of which decreased with increasing steric demand of the Ar group, together with [PtCl2{NC(O)Ph(TeArMes)}2]. The telluroether in the latter binds to nitrogen, and tellurium exists in the formal oxidation state of +4 (from XPS). The tellurium in these complexes exhibits secondary interactions with platinum (J((195)Pt-(125)Te) = 309-347 Hz) and with the carbonyl oxygen. These complexes slowly dissociate in solution to give [PtCl2(TeMesAr){NC(O)Ph(TeMesAr)}], finally leading to the formation of [PtCl2(TeMesAr)2]. Molecular structures of trans-[PtCl2(PhCN){NC(O)Ph[TeMes(o-tol)]}], trans-[PtCl2{NC(O)Ph(TeMes2)}2], trans-[PtCl2{NC(Ph)C4H7O}{NC(O)Ph(TeMes2)}], trans-[PtCl2{NC(O)Ph[TeMes(o-tol)]}2], trans-[PtCl2(TeMes2){NC(O)Ph(TeMes2)}], trans-[PtCl2{NC(O)Me(TeMes2)}2], and [PtCl(Te-o-tol){NC(O)Ph}2] have been unambiguously established by single-crystal X-ray diffraction analyses. Density functional theory calculations for some of the complexes were performed, and geometrical parameters are in good agreement with the values obtained from X-ray analyses. PMID:26669361

  18. Organizational Theories and Analysis: A Feminist Perspective

    NASA Astrophysics Data System (ADS)

    Irefin, Peace; Ifah, S. S.; Bwala, M. H.

    2012-06-01

    This paper is a critique of organization theories and their failure to come to terms with the fact of the reproduction of labour power within a particular form of the division of labour. It examines feminist theory and its aims to understand the nature of inequality and focuses on gender, power relations and sexuality part of the task of feminists which organizational theories have neglected is to offer an account of how the different treatments of the sexes operate in our culture. The paper concludes that gender has been completely neglected within the organizational theory which result in a rhetorical reproduction of males as norms and women as others. It is recommended that only radical form of organization theory can account for the situation of women in organisational setting

  19. Competing failure risk analysis using evidence theory.

    PubMed

    Helton, Jon C; Oberkampf, William L; Johnson, Jay D

    2005-08-01

    Safety systems are important components of high-consequence systems that are intended to prevent the unintended operation of the system and thus the potentially significant negative consequences that could result from such an operation. This presentation investigates and illustrates formal procedures for assessing the uncertainty in the probability that a safety system will fail to operate as intended in an accident environment. Probability theory and evidence theory are introduced as possible mathematical structures for the representation of the epistemic uncertainty associated with the performance of safety systems, and a representation of this type is illustrated with a hypothetical safety system involving one weak link and one strong link that is exposed to a high temperature fire environment. Topics considered include (1) the nature of diffuse uncertainty information involving a system and its environment, (2) the conversion of diffuse uncertainty information into the mathematical structures associated with probability theory and evidence theory, and (3) the propagation of these uncertainty structures through a model for a safety system to obtain representations in the context of probability theory and evidence theory of the uncertainty in the probability that the safety system will fail to operate as intended. The results suggest that evidence theory provides a potentially valuable representational tool for the display of the implications of significant epistemic uncertainty in inputs to complex analyses. PMID:16268945

  20. Interactive analysis program activity

    NASA Technical Reports Server (NTRS)

    Young, J. P.; Frisch, H. P.; Jones, G. K.; Walker, W. J.

    1980-01-01

    The development of an analysis software system capable of performing interdisciplinary preliminary design analyses of large space structure configurations is discussed. Disciplines such as thermal, structures, and controls are to be integrated into a highly user oriented analysis capability. The key feature of the integrated analysis capability, a rapid and efficient system that will minimize solution turnaround time, is discussed.

  1. A Theory Bite on Learning through Mathematical Activity

    ERIC Educational Resources Information Center

    Steffe, Leslie P.

    2011-01-01

    In this article, the author wishes to emphasize two fundamental points related to theory that were significantly underplayed in Simon et al.'s "A Developing Approach to Studying Students' Learning through Their Mathematical Activity" (2010). The author believes these points are central to any study of children's mathematical learning. The first…

  2. Instructional Transaction Theory: Knowledge Relationships among Processes, Entities, and Activities.

    ERIC Educational Resources Information Center

    Merrill, M. David; And Others

    1993-01-01

    Discussion of instructional transaction theory focuses on knowledge representation in an automated instructional design expert system. A knowledge structure called PEA-Net (processes, entities, and activities) is explained; the refrigeration process is used as an example; text resources and graphic resources are described; and simulations are…

  3. Engestrom's Version of Activity Theory: A Conservative Praxis?

    ERIC Educational Resources Information Center

    Avis, James

    2007-01-01

    This article examines Engestrom's version of activity theory, one rooted in Marxism. It is argued that whilst this approach holds progressive possibilities, its radicalism is undermined by a restricted conceptualisation of transformation and the marginalisation of a politicised notion of social antagonism. As a consequence, this approach to…

  4. "Vygotsky's Neglected Legacy": Cultural-Historical Activity Theory

    ERIC Educational Resources Information Center

    Roth, Wolff-Michael; Lee, Yew-Jin

    2007-01-01

    The authors describe an evolving theoretical framework that has been called one of the best kept secrets of academia: cultural-historical activity theory, the result of proposals Lev Vygotsky first articulated but that his students and followers substantially developed to constitute much expanded forms in its second and third generations. Besides…

  5. Anthropological Approach and Activity Theory: Culture, Communities and Institutions

    ERIC Educational Resources Information Center

    Lagrange, Jean-Baptiste

    2013-01-01

    The goal of this paper is to evaluate the contribution of the anthropological approach (AA) concurrently to Activity Theory (AT) in view of overarching questions about classroom use of technology for teaching and learning mathematics. I will do it first from a philosophical point of view, presenting the main notions of AA that have been used to…

  6. Freudian theory and consciousness: a conceptual analysis**.

    PubMed

    De Sousa, Avinash

    2011-01-01

    This paper aims at taking a fresh look at Freudian psychoanalytical theory from a modern perspective. Freudian psychology is a science based on the unconscious (id) and the conscious (ego). Various aspects of Freudian thinking are examined from a modern perspective and the relevance of the psychoanalytical theory of consciousness is projected. Do psychoanalysis and the unconsciousness have something to teach us about consciousness? Approaching Freud from a historical, psychoanalytical, anthropological and sociological perspective, we need to look at how Freudian theory may contribute to a better understanding of consciousness. We also need to look at psychoanalytical psychotherapy and its contribution to a better understanding of body-mind dualism and consciousness as a whole. Ego psychology is considered in the present day context and it is synthesized with various psychological studies to give us a better understanding of consciousness. PMID:21694972

  7. Towards a quantitative kinetic theory of polar active matter

    NASA Astrophysics Data System (ADS)

    Ihle, T.

    2014-06-01

    A recent kinetic approach for Vicsek-like models of active particles is reviewed. The theory is based on an exact Chapman- Kolmogorov equation in phase space. It can handle discrete time dynamics and "exotic" multi-particle interactions. A nonlocal mean-field theory for the one-particle distribution function is obtained by assuming molecular chaos. The Boltzmann approach of Bertin, et al., Phys. Rev. E 74, 022101 (2006) and J. Phys. A 42, 445001 (2009), is critically assessed and compared to the current approach. In Boltzmann theory, a collision starts when two particles enter each others action spheres and is finished when their distance exceeds the interaction radius. The average duration of such a collision, τ0, is measured for the Vicsek model with continuous time-evolution. If the noise is chosen to be close to the flocking threshold, the average time between collisions is found to be roughly equal to τ0 at low densities. Thus, the continuous-time Vicsek-model near the flocking threshold cannot be accurately described by a Boltzmann equation, even at very small density because collisions take so long that typically other particles join in, rendering Boltzmann's binary collision assumption invalid. Hydrodynamic equations for the phase space approach are derived by means of a Chapman-Enskog expansion. The equations are compared to the Toner-Tu theory of polar active matter. New terms, absent in the Toner-Tu theory, are highlighted. Convergence problems of Chapman-Enskog and similar gradient expansions are discussed.

  8. Analysis of composite laminates with a generalized zigzag theory

    SciTech Connect

    Liu, D.; Li, X.

    1994-12-31

    This study presents a generalized expression for laminate theories, namely a generalized zigzag theory. It unifies shear deformation theories, layerwise theories, and zigzag theories. To begin with, two layer-dependent variables are assumed for each in-plane displacement components. The layer-dependent variables can be converted into layer-independent variables through the enforcement of continuity conditions for both interlaminar displacements and interlaminar shear stresses. The total number of degrees-of-freedom of the theory then becomes layer-number independent and the computational efficiency is thus guaranteed. Since the properties of individual layers are considered in the analysis, the generalized zigzag theory gives excellent in-plane displacements and stresses in the cases examined by Pagano. Satisfactory transverse shear stresses can also be obtained directly from the constitutive equations. Although the interlaminar normal stresses are not forced to be continuous on the laminate interfaces, the discrepancy seems to be very insignificant.

  9. Modernity, the Individual, and the Foundations of Cultural-Historical Activity Theory

    ERIC Educational Resources Information Center

    Blunden, Andy

    2007-01-01

    It is argued that the problem of individual agency in relation to social institutions can be resolved within Cultural-Historical Activity Theory (CHAT) by the use of the "subject" as a unit of analysis. Such an approach implies a reaffirmation of the fundamental tenets of CHAT but also a critique of the concepts of society and culture, which are…

  10. Modeling of Active Transmembrane Transport in a Mixture Theory Framework

    PubMed Central

    Ateshian, Gerard A.; Morrison, Barclay; Hung, Clark T.

    2010-01-01

    This study formulates governing equations for active transport across semi-permeable membranes within the framework of the theory of mixtures. In mixture theory, which models the interactions of any number of fluid and solid constituents, a supply term appears in the conservation of linear momentum to describe momentum exchanges among the constituents. In past applications, this momentum supply was used to model frictional interactions only, thereby describing passive transport processes. In this study, it is shown that active transport processes, which impart momentum to solutes or solvent, may also be incorporated in this term. By projecting the equation of conservation of linear momentum along the normal to the membrane, a jump condition is formulated for the mechano-electrochemical potential of fluid constituents which is generally applicable to nonequilibrium processes involving active transport. The resulting relations are simple and easy to use, and address an important need in the membrane transport literature. PMID:20213212

  11. An item response theory analysis of the Sexual Compulsivity Scale and its correspondence with the Hypersexual Disorder Screening Inventory among a sample of highly sexually active gay and bisexual men

    PubMed Central

    Ventuneac, Ana; Rendina, H. Jonathon; Grov, Christian; Mustanski, Brian; Parsons, Jeffrey T.

    2015-01-01

    Introduction Numerous scales and assessments are available to assess sexual compulsivity (SC). Aim This study sought to conduct an Item Response Theory (IRT) analysis of the Sexual Compulsivity Scale (SCS) to provide evidence about its measurement precision at the various levels of the SC construct in a sample of highly sexually active gay and bisexual men (GBM). Methods SCS data from a sample of 202 GBM who are highly sexually active but who vary in their experiences of SC symptoms were modeled using Samejima's polytomous graded response IRT model. To describe the performance of the SCS relative to the HDSI, SCS scores were compared with participants’ corresponding HDSI results to determine sensitivity, specificity, positive and negative predictive values, and accuracy. Main Outcome Measures This study examined the correspondence between the SCS and the Hypersexual Disorder Screening Inventory (HDSI), a diagnostic instrument for the screening of hypersexuality. Results IRT analyses indicated that, although two of the SCS items had low reliability, the SCS as a whole was reliable across much of the SC continuum. Scores on the SCS and the HDSI were highly correlated; however, no potential cutoffs on the SCS corresponded strongly with the polythetic scoring criteria of the HDSI. Conclusion Comparisons of SCS scores with HDSI results indicated that the SCS itself could not serve as a substitute for the HDSI and would incorrectly classify a substantial number of individuals’ levels of hypersexuality. However, the SCS could be a useful screening tool to provide a preliminary screening of people at risk for meeting criteria on the HDSI. Combining the SCS and the HDSI may be an appropriate evaluation strategy in classifying GBM as negative on both (i.e., “non-hypersexual/non-SC”), positive on the SCS only (i.e., “at risk”), and positive on both the SCS and the HDSI (i.e., “problematic hypersexuality/SC”). PMID:25496349

  12. Bank robberies by an Asian gang: an assessment of the routine activities theory.

    PubMed

    Wang, John Z

    2002-10-01

    It was reported for the first time that a series of bank robberies were committed by an Asian gang group in a major southern city. The bank robberies showed a variety of operational methods. The purpose of this descriptive study is to apply the routine activities theory to explain the causal factors of the robberies. The analysis shows that the six Asian bank robberies resulted from a supply of motivated offenders, the availability of suitable targets, and a low level of capable guardians against crime. Findings suggest that crime-specific measures are an appropriate method for examining the merits of the routine activities theory. PMID:12365143

  13. Symmetry analysis for anisotropic field theories

    SciTech Connect

    Parra, Lorena; Vergara, J. David

    2012-08-24

    The purpose of this paper is to study with the help of Noether's theorem the symmetries of anisotropic actions for arbitrary fields which generally depend on higher order spatial derivatives, and to find the corresponding current densities and the Noether charges. We study in particular scale invariance and consider the cases of higher derivative extensions of the scalar field, electrodynamics and Chern-Simons theory.

  14. Psychosocial Factors and Theory in Physical Activity Studies in Minorities

    PubMed Central

    Mama, Scherezade K.; McNeill, Lorna H.; McCurdy, Sheryl A.; Evans, Alexandra E.; Diamond, Pamela M.; Adamus-Leach, Heather J.; Lee, Rebecca E.

    2015-01-01

    Objectives To summarize the effectiveness of interventions targeting psychosocial factors to increase physical activity (PA) among ethnic minority adults and explore theory use in PA interventions. Methods Studies (N = 11) were identified through a systematic review and targeted African American/Hispanic adults, specific psychosocial factors, and PA. Data were extracted using a standard code sheet and the Theory Coding Scheme. Results Social support was the most common psychosocial factor reported, followed by motivational readiness, and self-efficacy, as being associated with increased PA. Only 7 studies explicitly reported using a theoretical framework. Conclusions Future efforts should explore theory use in PA interventions and how integration of theoretical constructs, including psychosocial factors, increases PA. PMID:25290599

  15. Contrastive analysis of multiple exciton generation theories

    NASA Astrophysics Data System (ADS)

    Tan, Hengyu; Chang, Qing

    2015-10-01

    Multiple exciton generation (MEG) is an effect that semiconductor nanocrystals (NCs) quantum dots (QDs) generate multiple excitons (electron-hole pairs) through absorbing a single high energy photon. It can translate the excess photon energy of bandgap (Eg) into new excitons instead of heat loss and improve the photovoltaic performance of solar cells. However, the theories of MEG are not uniform. The main MEG theories can be divided into three types. The first is impact ionization. It explains MEG through a conventional way that a photogenerated exciton becomes multiple excitons by Coulomb interactions between carriers. The Second is coherent superposition of excitonic states. Multiple excitons are generated by the coherent superposition of single photogenerated exciton state with enough excess momentum and the two-exciton state with the same momentum. The third is excitation via virtual excitonic states. The nanocrystals vacuum generates a virtual biexciton by coulomb coupling between two valence band electrons. The virtual biexciton absorbing a photon with an intraband optical transition is converted into a real biexciton. This paper describes the MEG influence on solar photoelectric conversion efficiency, concludes and analyzes the fundamentals of different MEG theories, the MEG experimental measure, their merits and demerits, calculation methods of generation efficiency.

  16. Using Activity Theory to Model the Taiwan Atayal Students' Classroom Mathematical Activity

    ERIC Educational Resources Information Center

    Huang, Chih-Hsien; Lin, Fou-Lai

    2013-01-01

    From the sociocultural perspective, this research utilized activity theory as the theoretical framework to analyze the influences of cultural factors for Taiwanese Atayal junior high school students' study in mathematics. The research methodology adopted grounded theory, theoretical and methodological approaches which are illustrated through…

  17. A comparison between John Dewey's theory of inquiry and Jean Piaget's genetic analysis of intelligence.

    PubMed

    Seltzer, E

    1977-06-01

    This article compares John Dewey's theory of inquiry with Jean Piaget's analysis of the mechanisms implied in the increase of knowledge. The sources for this paper are Dewey's studies on logic and the theory of inquiry and Piaget's historical-critical and psychogenetic investigations. Three major conclusions result from the comparison: first, there are significant convergences between the two theories; second, Piaget's developmental analysis makes explicit what is programmatic in Dewey's investigations; and, finally, Piaget is incorrect in characterizing Dewey's pragmatism as a method that does not meet the criteria of intelligent activity. PMID:328823

  18. Stability analysis through bifurcation theory, 2

    NASA Astrophysics Data System (ADS)

    Guicheteau, P.

    1993-06-01

    This communication follows a previous communication which was presented in the same Agard Lecture Series (LS 191). In the previous communication, some theoretical foundations of Bifurcation Theory were recalled and a methodology aiming at a systematic prediction of the behavior of non-linear differential equations was presented. This communication mentions some problems which are connected with the introduction of control laws in order to stabilize an unstable dynamic system and presents a brief state of the art related to the determination of the attracting region of a stable equilibrium point.

  19. Asteroid orbital error analysis: Theory and application

    NASA Technical Reports Server (NTRS)

    Muinonen, K.; Bowell, Edward

    1992-01-01

    We present a rigorous Bayesian theory for asteroid orbital error estimation in which the probability density of the orbital elements is derived from the noise statistics of the observations. For Gaussian noise in a linearized approximation the probability density is also Gaussian, and the errors of the orbital elements at a given epoch are fully described by the covariance matrix. The law of error propagation can then be applied to calculate past and future positional uncertainty ellipsoids (Cappellari et al. 1976, Yeomans et al. 1987, Whipple et al. 1991). To our knowledge, this is the first time a Bayesian approach has been formulated for orbital element estimation. In contrast to the classical Fisherian school of statistics, the Bayesian school allows a priori information to be formally present in the final estimation. However, Bayesian estimation does give the same results as Fisherian estimation when no priori information is assumed (Lehtinen 1988, and reference therein).

  20. Effective field theory analysis of Higgs naturalness

    SciTech Connect

    Bar-Shalom, Shaouly; Soni, Amarjit; Wudka, Jose

    2015-07-20

    Assuming the presence of physics beyond the Standard Model ( SM) with a characteristic scale M ~ O (10) TeV, we investigate the naturalness of the Higgs sector at scales below M using an effective field theory (EFT) approach. We obtain the leading 1 -loop EFT contributions to the Higgs mass with a Wilsonian-like hard cutoff, and determine t he constraints on the corresponding operator coefficients for these effects to alleviate the little hierarchy problem up to the scale of the effective action Λ < M , a condition we denote by “EFT-naturalness”. We also determine the types of physics that can lead to EFT-naturalness and show that these types of new physics are best probed in vector-boson and multiple-Higgs production. The current experimental constraints on these coefficients are also discussed.

  1. Relativistic timescale analysis suggests lunar theory revision

    NASA Astrophysics Data System (ADS)

    Deines, Steven D.; Williams, Carol A.

    1995-05-01

    The SI second of the atomic clock was calibrated to match the Ephemeris Time (ET) second in a mutual four year effort between the National Physical Laboratory (NPL) and the United States Naval Observatory (USNO). The ephemeris time is 'clocked' by observing the elapsed time it takes the Moon to cross two positions (usually occultation of stars relative to a position on Earth) and dividing that time span into the predicted seconds according to the lunar equations of motion. The last revision of the equations of motion was the Improved Lunar Ephemeris (ILE), which was based on E. W. Brown's lunar theory. Brown classically derived the lunar equations from a purely Newtonian gravity with no relativistic compensations. However, ET is very theory dependent and is affected by relativity, which was not included in the ILE. To investigate the relativistic effects, a new, noninertial metric for a gravitated, translationally accelerated and rotating reference frame has three sets of contributions, namely (1) Earth's velocity, (2) the static solar gravity field and (3) the centripetal acceleration from Earth's orbit. This last term can be characterized as a pseudogravitational acceleration. This metric predicts a time dilation calculated to be -0.787481 seconds in one year. The effect of this dilation would make the ET timescale run slower than had been originally determined. Interestingly, this value is within 2 percent of the average leap second insertion rate, which is the result of the divergence between International Atomic Time (TAI) and Earth's rotational time called Universal Time (UT or UTI). Because the predictions themselves are significant, regardless of the comparison to TAI and UT, the authors will be rederiving the lunar ephemeris model in the manner of Brown with the relativistic time dilation effects from the new metric to determine a revised, relativistic ephemeris timescale that could be used to determine UT free of leap second adjustments.

  2. Relativistic timescale analysis suggests lunar theory revision

    NASA Technical Reports Server (NTRS)

    Deines, Steven D.; Williams, Carol A.

    1995-01-01

    The SI second of the atomic clock was calibrated to match the Ephemeris Time (ET) second in a mutual four year effort between the National Physical Laboratory (NPL) and the United States Naval Observatory (USNO). The ephemeris time is 'clocked' by observing the elapsed time it takes the Moon to cross two positions (usually occultation of stars relative to a position on Earth) and dividing that time span into the predicted seconds according to the lunar equations of motion. The last revision of the equations of motion was the Improved Lunar Ephemeris (ILE), which was based on E. W. Brown's lunar theory. Brown classically derived the lunar equations from a purely Newtonian gravity with no relativistic compensations. However, ET is very theory dependent and is affected by relativity, which was not included in the ILE. To investigate the relativistic effects, a new, noninertial metric for a gravitated, translationally accelerated and rotating reference frame has three sets of contributions, namely (1) Earth's velocity, (2) the static solar gravity field and (3) the centripetal acceleration from Earth's orbit. This last term can be characterized as a pseudogravitational acceleration. This metric predicts a time dilation calculated to be -0.787481 seconds in one year. The effect of this dilation would make the ET timescale run slower than had been originally determined. Interestingly, this value is within 2 percent of the average leap second insertion rate, which is the result of the divergence between International Atomic Time (TAI) and Earth's rotational time called Universal Time (UT or UTI). Because the predictions themselves are significant, regardless of the comparison to TAI and UT, the authors will be rederiving the lunar ephemeris model in the manner of Brown with the relativistic time dilation effects from the new metric to determine a revised, relativistic ephemeris timescale that could be used to determine UT free of leap second adjustments.

  3. Theories of the syllogism: A meta-analysis.

    PubMed

    Khemlani, Sangeet; Johnson-Laird, P N

    2012-05-01

    Syllogisms are arguments about the properties of entities. They consist of 2 premises and a conclusion, which can each be in 1 of 4 "moods": All A are B, Some A are B, No A are B, and Some A are not B. Their logical analysis began with Aristotle, and their psychological investigation began over 100 years ago. This article outlines the logic of inferences about syllogisms, which includes the evaluation of the consistency of sets of assertions. It also describes the main phenomena of reasoning about properties. There are 12 extant theories of such inferences, and the article outlines each of them and describes their strengths and weaknesses. The theories are of 3 main sorts: heuristic theories that capture principles that could underlie intuitive responses, theories of deliberative reasoning based on formal rules of inference akin to those of logic, and theories of deliberative reasoning based on set-theoretic diagrams or models. The article presents a meta-analysis of these extant theories of syllogisms using data from 6 studies. None of the 12 theories provides an adequate account, and so the article concludes with a guide-based on its qualitative and quantitative analyses-of how best to make progress toward a satisfactory theory. PMID:22289108

  4. Activation analysis using Cornell TRIGA

    SciTech Connect

    Hossain, Tim Z.

    1994-07-01

    A major use of the Cornell TRIGA is for activation analysis. Over the years many varieties of samples have been analyzed from a number of fields of interest ranging from geology, archaeology and textiles. More recently the analysis has been extended to high technology materials for applications in optical and semiconductor devices. Trace analysis in high purity materials like Si wafers has been the focus in many instances, while in others analysis of major/minor components were the goals. These analysis has been done using the delayed mode. Results from recent measurements in semiconductors and other materials will be presented. In addition the near future capability of using prompt gamma activation analysis using the Cornell cold neutron beam will be discussed. (author)

  5. Standardizing Activation Analysis: New Software for Photon Activation Analysis

    SciTech Connect

    Sun, Z. J.; Wells, D.; Green, J.; Segebade, C.

    2011-06-01

    Photon Activation Analysis (PAA) of environmental, archaeological and industrial samples requires extensive data analysis that is susceptible to error. For the purpose of saving time, manpower and minimizing error, a computer program was designed, built and implemented using SQL, Access 2007 and asp.net technology to automate this process. Based on the peak information of the spectrum and assisted by its PAA library, the program automatically identifies elements in the samples and calculates their concentrations and respective uncertainties. The software also could be operated in browser/server mode, which gives the possibility to use it anywhere the internet is accessible. By switching the nuclide library and the related formula behind, the new software can be easily expanded to neutron activation analysis (NAA), charged particle activation analysis (CPAA) or proton-induced X-ray emission (PIXE). Implementation of this would standardize the analysis of nuclear activation data. Results from this software were compared to standard PAA analysis with excellent agreement. With minimum input from the user, the software has proven to be fast, user-friendly and reliable.

  6. Comparative Lifecycle Energy Analysis: Theory and Practice.

    ERIC Educational Resources Information Center

    Morris, Jeffrey; Canzoneri, Diana

    1992-01-01

    Explores the position that more energy is conserved through recycling secondary materials than is generated from municipal solid waste incineration. Discusses one component of a lifecycle analysis--a comparison of energy requirements for manufacturing competing products. Includes methodological issues, energy cost estimates, and difficulties…

  7. LINGUISTIC FOUNDATIONS FOR A THEORY OF CONTENT ANALYSIS.

    ERIC Educational Resources Information Center

    HAYS, DAVID G.

    THIS PAPER DISCUSSES THE THEORY THAT CONTENT ANALYSIS OF MESSAGES IS A CONTRAL TOPIC IN ALL SCIENCES DEALING WITH MAN. CONTENT ANALYSIS IS THE DETERMINATION OF CHARACTERISTICS OF A SOURCE FROM THE NATURAL LANGUAGE UTTERANCES IT EMITS. ASSIGNING PROPERTIES TO WORDS AND THEN COUNTING THE APPEARANCES OF THE PROPERTIES IS INSUFFICIENT--THE CONTENT OF…

  8. The Constant Comparative Analysis Method Outside of Grounded Theory

    ERIC Educational Resources Information Center

    Fram, Sheila M.

    2013-01-01

    This commentary addresses the gap in the literature regarding discussion of the legitimate use of Constant Comparative Analysis Method (CCA) outside of Grounded Theory. The purpose is to show the strength of using CCA to maintain the emic perspective and how theoretical frameworks can maintain the etic perspective throughout the analysis. My…

  9. Law and Technology Theory: Bringing in Some Economic Analysis

    ERIC Educational Resources Information Center

    Trosow, Samuel

    2010-01-01

    The author argues economic analysis needs to be explicitly included in an overall theory of law and technology. Differing approaches to the economics of information are considered, and the copyright policy environment of the 1990s is taken as an example of how the lack of substantive economic analysis resulted in poor policy-making.

  10. Prediction of attendance at fitness center: a comparison between the theory of planned behavior, the social cognitive theory, and the physical activity maintenance theory.

    PubMed

    Jekauc, Darko; Völkle, Manuel; Wagner, Matthias O; Mess, Filip; Reiner, Miriam; Renner, Britta

    2015-01-01

    In the processes of physical activity (PA) maintenance specific predictors are effective, which differ from other stages of PA development. Recently, Physical Activity Maintenance Theory (PAMT) was specifically developed for prediction of PA maintenance. The aim of the present study was to evaluate the predictability of the future behavior by the PAMT and compare it with the Theory of Planned Behavior (TPB) and Social Cognitive Theory (SCT). Participation rate in a fitness center was observed for 101 college students (53 female) aged between 19 and 32 years (M = 23.6; SD = 2.9) over 20 weeks using a magnetic card. In order to predict the pattern of participation TPB, SCT and PAMT were used. A latent class zero-inflated Poisson growth curve analysis identified two participation patterns: regular attenders and intermittent exercisers. SCT showed the highest predictive power followed by PAMT and TPB. Impeding aspects as life stress and barriers were the strongest predictors suggesting that overcoming barriers might be an important aspect for working out on a regular basis. Self-efficacy, perceived behavioral control, and social support could also significantly differentiate between the participation patterns. PMID:25717313

  11. Prediction of attendance at fitness center: a comparison between the theory of planned behavior, the social cognitive theory, and the physical activity maintenance theory

    PubMed Central

    Jekauc, Darko; Völkle, Manuel; Wagner, Matthias O.; Mess, Filip; Reiner, Miriam; Renner, Britta

    2015-01-01

    In the processes of physical activity (PA) maintenance specific predictors are effective, which differ from other stages of PA development. Recently, Physical Activity Maintenance Theory (PAMT) was specifically developed for prediction of PA maintenance. The aim of the present study was to evaluate the predictability of the future behavior by the PAMT and compare it with the Theory of Planned Behavior (TPB) and Social Cognitive Theory (SCT). Participation rate in a fitness center was observed for 101 college students (53 female) aged between 19 and 32 years (M = 23.6; SD = 2.9) over 20 weeks using a magnetic card. In order to predict the pattern of participation TPB, SCT and PAMT were used. A latent class zero-inflated Poisson growth curve analysis identified two participation patterns: regular attenders and intermittent exercisers. SCT showed the highest predictive power followed by PAMT and TPB. Impeding aspects as life stress and barriers were the strongest predictors suggesting that overcoming barriers might be an important aspect for working out on a regular basis. Self-efficacy, perceived behavioral control, and social support could also significantly differentiate between the participation patterns. PMID:25717313

  12. Optomechanical shape analysis using group theory.

    PubMed

    Magnes, Jenny; Kinneberg, Margo; Khakurel, Rahul; Melikechi, Noureddine

    2010-08-01

    We describe an optomechanical technique using a knife-edge, which is scanned spatially across a beam of light to identify shape-based irradiance. Symmetry groups are identified through linear and rotational scanning signatures of illuminated shapes. The scanning signature is used to classify the shape into a symmetry group. To demonstrate the shape analysis technique, we have classified basic geometric shapes, which belong to the orthogonal and dihedral symmetry groups O(2), D(2), D(3), and D(6). PMID:20676172

  13. Use of group theory for the analysis of vibrational spectra

    NASA Astrophysics Data System (ADS)

    Rykhlinskaya, K.; Fritzsche, S.

    2004-09-01

    To facilitate the use of group theory in the analysis of vibrational spectra, a set of Maple procedures is provided generating the normal coordinates and determining the spectral activities of polyatomic molecules. Our program, called BETHE, is based on the frequently applied point groups and provides an interactive access to the group data as needed in physical chemistry and elsewhere. Owing to the demand of the users the normal coordinates of the molecules are provided either in terms of Cartesian or internal coordinates. Program summaryTitle of program:BETHE Catalogue number: ADUH Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADUH Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Licensing provisions:None Computers for which the program is designed: All computers with a license of the computer algebra package MAPLE Installations:University of Kassel (Germany) Operating systems under which the program has been tested: Linux 8.1+ and Windows 2000 Program language used:MAPLE 7 and 8 Memory required to execute with typical data: 10-30 MB No. of lines in distributed program including test data, etc.:11 859 No. of bytes in distributed program including test data, etc.:312 229 Distribution format:tar.gz Nature of the physical problem: Interaction of the infrared light with the molecule can lead to the excitation of the molecular vibrations [1]. Analysis of such vibrations is performed by the point group theory and helps to interpret the molecular spectra. Method of solution: Point group theory is applied to determine the normal coordinates of symmetric molecules and to carry out a spectroscopic analysis of their vibrational modes. The direct product of the irreducible representations is utilized to obtain the selection rules for infrared and Raman spectroscopy. Restrictions onto the complexity of the problem: The computation of the normal coordinates is supported for rather a large number of symmetries; in the present

  14. Theory-Driven Intervention for Changing Personality: Expectancy Value Theory, Behavioral Activation, and Conscientiousness

    PubMed Central

    Magidson, Jessica F.; Roberts, Brent; Collado-Rodriguez, Anahi; Lejuez, C.W.

    2013-01-01

    Considerable evidence suggests that personality traits may be changeable, raising the possibility that personality traits most linked to health problems can be modified with intervention. A growing body of research suggests that problematic personality traits may be altered with behavioral intervention using a bottom-approach. That is, by targeting core behaviors that underlie personality traits with the goal of engendering new, healthier patterns of behavior that over time become automatized and manifest in changes in personality traits. Nevertheless, a bottom-up model for changing personality traits is somewhat diffuse and requires clearer integration of theory and relevant interventions to enable real clinical application. As such, this manuscript proposes a set of guiding principles for theory-driven modification of targeted personality traits using a bottom-up approach, focusing specifically on targeting the trait of conscientiousness using a relevant behavioral intervention, Behavioral Activation (BA), considered within the motivational framework of Expectancy Value Theory (EVT). We conclude with a real case example of the application of BA to alter behaviors counter to conscientiousness in a substance dependent patient, highlighting the EVT principles most relevant to the approach and the importance and viability of a theoretically-driven, bottom-up approach to changing personality traits. PMID:23106844

  15. Theory of Activated Relaxation in Nanoscale Confined Liquids

    NASA Astrophysics Data System (ADS)

    Mirigian, Stephen; Schweizer, Kenneth

    2014-03-01

    We extend the recently developed Elastically Cooperative Nonlinear Langevin Equation(ECNLE) theory of activated relaxation in supercooled liquids to treat the case of geometrically confined liquids. Generically, confinement of supercooled liquids leads to a speeding up of the dynamics(with a consequent depression of the glass transition temperature) extending on the order of tens of molecular diameters away from a free surface. At present, this behavior is not theoretically well understood. Our theory interprets the speed up in dynamics in terms of two coupled effects. First, a direct surface effect, extending two to three molecular diameters from a free surface, and related to a local rearrangement of molecules with a single cage. The second is a longer ranged ``confinement'' effect, extending tens of molecular diameters from a free surface and related to the long range elastic penalty necessary for a local rearrangement. The theory allows for the calculation of relaxation time and Tg profiles within a given geometry and first principles calculations of relevant length scales. Comparison to both dynamic and pseudo-thermodynamic measurements shows reasonable agreement to experiment with no adjustable parameters.

  16. Facet Theory, Smallest Space Analysis, and Factor Analysis.

    ERIC Educational Resources Information Center

    Guttman, Louis

    1982-01-01

    Mathematical and statistical relationships between factor analysis and smallest space analysis are discussed. As spatial analysis of correlation matrices, factor analysis is a special case of smallest space analysis. The two differ in six ways: Shepard diagram, dimensionality, correction for communality, similarity coefficients, regions versus…

  17. Testing Punctuated Equilibrium Theory Using Evolutionary Activity Statistics

    NASA Astrophysics Data System (ADS)

    Woodberry, O. G.; Korb, K. B.; Nicholson, A. E.

    The Punctuated Equilibrium hypothesis (Eldredge and Gould,1972) asserts that most evolutionary change occurs during geologically rapid speciation events, with species exhibiting stasis most of the time. Punctuated Equilibrium is a natural extension of Mayr's theories on peripatric speciation via the founder effect, (Mayr, 1963; Eldredge and Gould, 1972) which associates changes in diversity to a population bottleneck. That is, while the formation of a foundation bottleneck brings an initial loss of genetic variation, it may subsequently result in the emergence of a child species distinctly different from its parent species. In this paper we adapt Bedau's evolutionary activity statistics (Bedau and Packard, 1991) to test these effects in an ALife simulation of speciation. We find a relative increase in evolutionary activity during speciations events, indicating that punctuation is occurring.

  18. The theory of an active magnetic regenerative refrigerator

    NASA Technical Reports Server (NTRS)

    Barclay, J. A.

    1983-01-01

    The adiabatic temperature change with field which is limited to about 2 K/Tesla for ferromagnets near their Curie temperatures by the change of magnetization with temperature and the lattice heat capacity is discussed. Practical magnetic refrigerators operate on a regenerative cycle such as the Brayton cycle. This cycle can be executed through the use of an active magnetic regenerator, i.e., a regenerator composed of magnetic material that is cycled in an out of a magnetic field with appropriate fluid flows. The theory of these devices is predicted by solving the partial differential equations that describe fluid and the magnetic solid. The active magnetic regenerator is described along with the method of calculation. Temperature profiles for a normal regenerator and a magnetic regenerative refrigerator are shown.

  19. Minimal continuum theories of structure formation in dense active fluids

    NASA Astrophysics Data System (ADS)

    Dunkel, Jörn; Heidenreich, Sebastian; Bär, Markus; Goldstein, Raymond E.

    2013-04-01

    Self-sustained dynamical phases of living matter can exhibit remarkable similarities over a wide range of scales, from mesoscopic vortex structures in microbial suspensions and motility assays of biopolymers to turbulent large-scale instabilities in flocks of birds or schools of fish. Here, we argue that, in many cases, the phenomenology of such active states can be efficiently described in terms of fourth- and higher-order partial differential equations. Structural transitions in these models can be interpreted as Landau-type kinematic transitions in Fourier (wavenumber) space, suggesting that microscopically different biological systems can share universal long-wavelength features. This general idea is illustrated through numerical simulations for two classes of continuum models for incompressible active fluids: a Swift-Hohenberg-type scalar field theory, and a minimal vector model that extends the classical Toner-Tu theory and appears to be a promising candidate for the quantitative description of dense bacterial suspensions. We discuss how microscopic symmetry-breaking mechanisms can enter macroscopic continuum descriptions of collective microbial motion near surfaces, and conclude by outlining future applications.

  20. Philosophic analysis of a theory of clinical nursing.

    PubMed

    Schafer, P J

    1987-01-01

    expansions have been constructed by students of the theorist. In the hierarchy of knowledge conceptualizations, Rubin's theory represents a disciplinary matrix: ordering theories, methods, and exemplars; giving direction to the development of theories of nursing that address empirical problems of the discipline; and cohering to the metaparadigm of nursing. Philosophic analysis of theories of nursing can yield an articulated, clearly depicted framework of concepts and their relationships from which new understandings may emerge. PMID:3450983

  1. Multiple Intelligences Theory and Iranian Textbooks: An Analysis

    ERIC Educational Resources Information Center

    Taase, Yoones

    2012-01-01

    The purpose of this study is to investigate locally designed ELT textbooks in the light of multiple intelligences theory. Three textbooks (grade 1.2.3) used in guidance school of Iranian educational system were analyzed using MI checklist developed by Botelho, Mario do Rozarioand. Catered for kinds of intelligences in the activities and exercises…

  2. Sensitivity analysis of state-specific multireference perturbation theory

    NASA Astrophysics Data System (ADS)

    Szabados, Ágnes

    2011-05-01

    State-specific multireference perturbation theory (SS-MRPT) developed by Mukherjee et al. [Int. J. Mol. Sci. 3, 733 (2002)] is examined focusing on the dependence of the perturbed energy on the initial model space coefficients. It has been observed earlier, that non-physical kinks may appear on the potential energy surface obtained by SS-MRPT while related coupled-cluster methods may face convergence difficulties. Though exclusion or damping of the division by small coefficients may alleviate the problem, it is demonstrated here that the effect does not originate in an ill-defined division. It is shown that non-negligible model space coefficients may also be linked with the problem. Sensitivity analysis is suggested as a tool for detecting the coefficient responsible. By monitoring the singular values of sensitivity matrices, orders of magnitude increase is found in the largest value, in the vicinity of the problematic geometry point on the potential energy surface. The drastic increase of coefficient sensitivities is found to be linked with a degeneracy of the target root of the effective Hamiltonian. The nature of the one-electron orbitals has a profound influence on the picture: a rotation among active orbitals may screen or worsen the effect.

  3. Phishing for suitable targets in the Netherlands: routine activity theory and phishing victimization.

    PubMed

    Leukfeldt, E Rutger

    2014-08-01

    This article investigates phishing victims, especially the increased or decreased risk of victimization, using data from a cybercrime victim survey in the Netherlands (n=10,316). Routine activity theory provides the theoretical perspective. According to routine activity theory, several factors influence the risk of victimization. A multivariate analysis was conducted to assess which factors actually lead to increased risk of victimization. The model included background and financial data of victims, their Internet activities, and the degree to which they were "digitally accessible" to an offender. The analysis showed that personal background and financial characteristics play no role in phishing victimization. Among eight Internet activities, only "targeted browsing" led to increased risk. As for accessibility, using popular operating systems and web browsers does not lead to greater risk, while having up-to-date antivirus software as a technically capable guardian has no effect. The analysis showed no one, clearly defined group has an increased chance of becoming a victim. Target hardening may help, but opportunities for prevention campaigns aimed at a specific target group or dangerous online activities are limited. Therefore, situational crime prevention will have to come from a different angle. Banks could play the role of capable guardian. PMID:25080013

  4. Aerodynamic preliminary analysis system 2. Part 1: Theory

    NASA Technical Reports Server (NTRS)

    Bonner, E.; Clever, W.; Dunn, K.

    1991-01-01

    An aerodynamic analysis system based on potential theory at subsonic and/or supersonic speeds and impact type finite element solutions at hypersonic conditions is described. Three dimensional configurations having multiple nonplanar surfaces of arbitrary planform and bodies of noncircular contour may be analyzed. Static, rotary, and control longitudinal and lateral directional characteristics may be generated. The analysis was implemented on a time sharing system in conjunction with an input tablet digitizer and an interactive graphics input/output display and editing terminal to maximize its responsiveness to the preliminary analysis problem. The program provides an efficient analysis for systematically performing various aerodynamic configuration tradeoff and evaluation studies.

  5. Applying Adult Learning Theory through a Character Analysis

    ERIC Educational Resources Information Center

    Baskas, Richard S.

    2011-01-01

    The purpose of this study is to analyze the behavior of a character, Celie, in a movie, 'The Color Purple," through the lens of two adult learning theorists to determine the relationships the character has with each theory. The development and portrayal of characters in movies can be explained and understood by the analysis of adult learning…

  6. The Use of Modelling for Theory Building in Qualitative Analysis

    ERIC Educational Resources Information Center

    Briggs, Ann R. J.

    2007-01-01

    The purpose of this article is to exemplify and enhance the place of modelling as a qualitative process in educational research. Modelling is widely used in quantitative research as a tool for analysis, theory building and prediction. Statistical data lend themselves to graphical representation of values, interrelationships and operational…

  7. Household Refuse Analysis: Theory, Method, and Applications in Social Science.

    ERIC Educational Resources Information Center

    Rathje, William L., Ed.; Ritenbaugh, Cheryl K., Ed.

    1984-01-01

    The articles in this issue explore the current parameters of household refuse analysis. An overview of garbage research studies is presented; research methodology, theories, and applications are examined. U.S. household refuse is compared to the discards of households in Mexico City. (RM)

  8. The Influence of Active Learning on the College Student Departure Process: Toward a Revision of Tinto's Theory.

    ERIC Educational Resources Information Center

    Braxton, John M.; Milem, Jeffrey F.; Sullivan, Anna Shaw

    2000-01-01

    Examined the influence of faculty active-learning practices on student departure decisions in the context of Tinto's Theory of College Student Departure. Path analysis results of three surveys of 718 first-time, full-time, first-year students at a highly selective private research university found that active learning exerts statistically reliable…

  9. Using Activity Theory to Evaluate a Professional Learning and Development Initiative in the Use of Narrative Assessment

    ERIC Educational Resources Information Center

    Bourke, Roseanna; Mentis, Mandia; O'Neill, John

    2013-01-01

    Analysis of the impact of professional learning and development (PLD) programmes for educators is complex. This article presents an analysis of a PLD initiative in which classroom teachers learned to use narrative assessment for students with "high" and "very high" learning needs. Using Cultural Historical Activity Theory (CHAT), the analysis…

  10. Towards a statistical mechanical theory of active fluids.

    PubMed

    Marini Bettolo Marconi, Umberto; Maggi, Claudio

    2015-12-01

    We present a stochastic description of a model of N mutually interacting active particles in the presence of external fields and characterize its steady state behavior in the absence of currents. To reproduce the effects of the experimentally observed persistence of the trajectories of the active particles we consider a Gaussian force having a non-vanishing correlation time τ, whose finiteness is a measure of the activity of the system. With these ingredients we show that it is possible to develop a statistical mechanical approach similar to the one employed in the study of equilibrium liquids and to obtain the explicit form of the many-particle distribution function by means of the multidimensional unified colored noise approximation. Such a distribution plays a role analogous to the Gibbs distribution in equilibrium statistical mechanics and provides complete information about the microscopic state of the system. From here we develop a method to determine the one- and two-particle distribution functions in the spirit of the Born-Green-Yvon (BGY) equations of equilibrium statistical mechanics. The resulting equations which contain extra-correlations induced by the activity allow us to determine the stationary density profiles in the presence of external fields, the pair correlations and the pressure of active fluids. In the low density regime we obtained the effective pair potential ϕ(r) acting between two isolated particles separated by a distance, r, showing the existence of an effective attraction between them induced by activity. Based on these results, in the second half of the paper we propose a mean field theory as an approach simpler than the BGY hierarchy and use it to derive a van der Waals expression of the equation of state. PMID:26387914

  11. From Activity to Learning: Using Cultural Historical Activity Theory to Model School Library Programmes and Practices

    ERIC Educational Resources Information Center

    Meyers, Eric M.

    2007-01-01

    Introduction: changes in educational policy and practice demand that we examine school library programmes from a new perspective. As a model that takes a developmental view of minds in context, Cultural Historical Activity Theory is particularly well suited to the study of school libraries and the learning that occurs therein. This paper focuses…

  12. Scaled-particle theory analysis of cylindrical cavities in solution.

    PubMed

    Ashbaugh, Henry S

    2015-04-01

    The solvation of hard spherocylindrical solutes is analyzed within the context of scaled-particle theory, which takes the view that the free energy of solvating an empty cavitylike solute is equal to the pressure-volume work required to inflate a solute from nothing to the desired size and shape within the solvent. Based on our analysis, an end cap approximation is proposed to predict the solvation free energy as a function of the spherocylinder length from knowledge regarding only the solvent density in contact with a spherical solute. The framework developed is applied to extend Reiss's classic implementation of scaled-particle theory and a previously developed revised scaled-particle theory to spherocylindrical solutes. To test the theoretical descriptions developed, molecular simulations of the solvation of infinitely long cylindrical solutes are performed. In hard-sphere solvents classic scaled-particle theory is shown to provide a reasonably accurate description of the solvent contact correlation and resulting solvation free energy per unit length of cylinders, while the revised scaled-particle theory fitted to measured values of the contact correlation provides a quantitative free energy. Applied to the Lennard-Jones solvent at a state-point along the liquid-vapor coexistence curve, however, classic scaled-particle theory fails to correctly capture the dependence of the contact correlation. Revised scaled-particle theory, on the other hand, provides a quantitative description of cylinder solvation in the Lennard-Jones solvent with a fitted interfacial free energy in good agreement with that determined for purely spherical solutes. The breakdown of classical scaled-particle theory does not result from the failure of the end cap approximation, however, but is indicative of neglected higher-order curvature dependences on the solvation free energy. PMID:25974499

  13. An Empirical Development of Critical Value Factors (CVF) of Online Learning Activities: An Application of Activity Theory and Cognitive Value Theory

    ERIC Educational Resources Information Center

    Levy, Yair

    2008-01-01

    According to activity theory, activities are at the center of human behavior. Extensive attention has been given in literature to the success and effectiveness of online learning programs. Value theory suggests that human perceived value is a critical construct in investigating what is important to individuals. However, very limited attention has…

  14. Role of colored noise in active dynamical theories

    NASA Astrophysics Data System (ADS)

    Kachan, Devin; Levine, Alex

    2015-03-01

    The noise driving many dynamical systems is temporally correlated, or colored. Biological motor proteins, for example, generate processive stresses in biopolymer networks, and it would be incorrect to model this forcing as uncorrelated white noise. To gain insight into the role of the noise spectrum, we study a phi⌃4 theory in the presence of active colored noise with renormalization group techniques. Using a frequency shell integration scheme, we perform an epsilon expansion around d =8 for power law noise of the form 1/f⌃2 and find frequency and wavevector dependent corrections to the transport coefficients. The power law noise assumption is, of course, an approximation: all physical processes possess a small frequency cutoff. We study the effect of this cutoff and find a change in scaling behavior as the system transitions from a power law divergent regime to one dominated by white noise.

  15. Theory of activated transport in bilayer quantum Hall systems.

    PubMed

    Roostaei, B; Mullen, K J; Fertig, H A; Simon, S H

    2008-07-25

    We analyze the transport properties of bilayer quantum Hall systems at total filling factor nu=1 in drag geometries as a function of interlayer bias, in the limit where the disorder is sufficiently strong to unbind meron-antimeron pairs, the charged topological defects of the system. We compute the typical energy barrier for these objects to cross incompressible regions within the disordered system using a Hartree-Fock approach, and show how this leads to multiple activation energies when the system is biased. We then demonstrate using a bosonic Chern-Simons theory that in drag geometries current in a single layer directly leads to forces on only two of the four types of merons, inducing dissipation only in the drive layer. Dissipation in the drag layer results from interactions among the merons, resulting in very different temperature dependences for the drag and drive layers, in qualitative agreement with experiment. PMID:18764355

  16. Theory of Activated Transport in Bilayer Quantum Hall Systems

    NASA Astrophysics Data System (ADS)

    Roostaei, Bahman; Fertig, Herbert; Mullen, Kieran; Simon, Steven

    2008-03-01

    We analyze the transport properties of bilayer quantum Hall systems at total filling factor ν= 1 in drag geometries as a function of interlayer bias, in the limit where the disorder is sufficiently strong to unbind meron-antimeron pairs, the charged topological defects of the system. We compute the typical energy barrier for these objects to cross incompressible regions within the disordered system using a Hartree-Fock approach, and show how this leads to multiple activation energies when the system is biased. We then demonstrate using a bosonic Chern- Simons theory that in drag geometries, current in a single layer directly leads to forces on only two of the four types of merons, inducing dissipation only in the drive layer. Dissipation in the drag layer results from interactions among the merons, resulting in very different temperature dependences for the drag and drive layers, in qualitative agreement with experiment. We conclude with predictions for future experiments.

  17. Theory of Activated Transport in Bilayer Quantum Hall Systems

    NASA Astrophysics Data System (ADS)

    Roostaei, B.; Mullen, K. J.; Fertig, H. A.; Simon, S. H.

    2008-07-01

    We analyze the transport properties of bilayer quantum Hall systems at total filling factor ν=1 in drag geometries as a function of interlayer bias, in the limit where the disorder is sufficiently strong to unbind meron-antimeron pairs, the charged topological defects of the system. We compute the typical energy barrier for these objects to cross incompressible regions within the disordered system using a Hartree-Fock approach, and show how this leads to multiple activation energies when the system is biased. We then demonstrate using a bosonic Chern-Simons theory that in drag geometries current in a single layer directly leads to forces on only two of the four types of merons, inducing dissipation only in the drive layer. Dissipation in the drag layer results from interactions among the merons, resulting in very different temperature dependences for the drag and drive layers, in qualitative agreement with experiment.

  18. The activation strain model and molecular orbital theory

    PubMed Central

    Wolters, Lando P; Bickelhaupt, F Matthias

    2015-01-01

    The activation strain model is a powerful tool for understanding reactivity, or inertness, of molecular species. This is done by relating the relative energy of a molecular complex along the reaction energy profile to the structural rigidity of the reactants and the strength of their mutual interactions: ΔE(ζ) = ΔEstrain(ζ) + ΔEint(ζ). We provide a detailed discussion of the model, and elaborate on its strong connection with molecular orbital theory. Using these approaches, a causal relationship is revealed between the properties of the reactants and their reactivity, e.g., reaction barriers and plausible reaction mechanisms. This methodology may reveal intriguing parallels between completely different types of chemical transformations. Thus, the activation strain model constitutes a unifying framework that furthers the development of cross-disciplinary concepts throughout various fields of chemistry. We illustrate the activation strain model in action with selected examples from literature. These examples demonstrate how the methodology is applied to different research questions, how results are interpreted, and how insights into one chemical phenomenon can lead to an improved understanding of another, seemingly completely different chemical process. WIREs Comput Mol Sci 2015, 5:324–343. doi: 10.1002/wcms.1221 PMID:26753009

  19. Neutron Activation Analysis: Techniques and Applications

    SciTech Connect

    MacLellan, Ryan

    2011-04-27

    The role of neutron activation analysis in low-energy low-background experimentsis discussed in terms of comparible methods. Radiochemical neutron activation analysis is introduce. The procedure of instrumental neutron activation analysis is detailed especially with respect to the measurement of trace amounts of natural radioactivity. The determination of reactor neutron spectrum parameters required for neutron activation analysis is also presented.

  20. Conformational Analysis of Thioether Musks Using Density Functional Theory

    PubMed Central

    Setzer, William N.

    2009-01-01

    A conformational analysis of nine macrocyclic thioether musks has been carried out using molecular mechanics (MMFF), density functional theory (DFT) using both B3LYP and M06 functionals, as well as Hartree-Fock and post-Hartree-Fock (MP2) ab initio methods. 6-Thia-, 10-thia- and 4-methyl-5-thia-14-tetradecananolide, 4-thia-, 7-thia-, 11-thia- and 12-thia-15-pentadecanolide and 6-thia- and 12-thia-16-hexadecanolide were modeled. Unfortunately, there was little agreement between the computational methods at the levels of theory used in this study. PMID:20111690

  1. Analysis of accelerated motion in the theory of relativity

    NASA Technical Reports Server (NTRS)

    Jones, R. T.

    1976-01-01

    Conventional treatments of accelerated motion in the theory of relativity have led to certain difficulties of interpretation. Certain reversals in the apparent gravitational field of an accelerated body may be avoided by simpler analysis based on the use of restricted conformal transformations. In the conformal theory the velocity of light remains constant even for experimenters in accelerated motion. The problem considered is that of rectilinear motion with a variable velocity. The motion takes place along the x or x' axis of two coordinate systems.

  2. Thought analysis on self-organization theories of MHD plasma

    NASA Astrophysics Data System (ADS)

    Kondoh, Yoshiomi; Sato, Tetsuya

    1992-08-01

    A thought analysis on the self-organization theories of dissipative MHD plasmas is presented to lead to three groups of theories that lead to the same relaxed state of del x B = lambda(B), in order to find an essential physical picture embedded in the self-organization phenomena due to nonlinear and dissipative processes. The self-organized relaxed state due to the dissipation by the Ohm loss is shown to be formulated generally as the state such that yields the minimum dissipation rate of global auto- and/or cross-correlations between two quantities in j, B, and A for their own instantaneous values of the global correlations.

  3. Building inhabitant feedback: Creating a reflective practice for environmental design using activity theory

    NASA Astrophysics Data System (ADS)

    Cunningham, Dara Suzanne

    The way buildings are designed now, there is little feedback from use involved in the design process. Attempts to correct this problem have been made in the form of Post Occupancy Evaluations (POEs) for 50-years but have largely failed. POEs are the accepted method for environmental designers to collect feedback about buildings in use. They are infrequently conducted, after the building is built, in a one-time only evaluation, and not funded as part of the build process. Other products receive feedback about the design in use from online critiques. Online critiques could provide a platform for feedback from actors engaged with buildings in use for environmental designers to utilize in developing reflective design rationale to avoid adverse consequences in future designs or correct consequences in past and current designs. Since buildings constitute such a large part of the human environment, it's important to research the effects of buildings on their inhabitants. In order for environmental designers to act on feedback from situated use, designers need to have access to that feedback and all actors interacting with the building design need to have an easy, inexpensive, and accessible method to submit feedback. These needs can be addressed by utilizing modern networked and mobile computing to collect and access building feedback. The analysis presented in this dissertation is informed by a thorough evaluation of the theory of reflective practice, activity theory, environmental design, and cognitive science research. From this analysis, I developed the following contributions. First, I expanded Schon's reflective practice by combining his theory with a modified version of activity theory, using activity theory to enrich reflective practice and create Reflective Activity Systems Theory (RAST), which provides a new framework to develop design rationale based on feedback from use and a focus on the activity. Second, I suggest the design of an activity information system

  4. LOGIC ANALYSIS: TESTING PROGRAM THEORY TO BETTER EVALUATE COMPLEX INTERVENTIONS

    PubMed Central

    Rey, Lynda; Brousselle, Astrid; Dedobbeleer, Nicole

    2016-01-01

    Evaluating complex interventions requires an understanding of the program’s logic of action. Logic analysis, a specific type of program theory evaluation based on scientific knowledge, can help identify either the critical conditions for achieving desired outcomes or alternative interventions for that purpose. In this article, we outline the principles of logic analysis and its roots. We then illustrate its use with an actual evaluation case. Finally, we discuss the advantages of conducting logic analysis prior to other types of evaluations. This article will provide evaluators with both theoretical and practical information to help them in conceptualizing their evaluations.

  5. Emotion at Work: A Contribution to Third-Generation Cultural-Historical Activity Theory

    ERIC Educational Resources Information Center

    Roth, Wolff-Michael

    2007-01-01

    Second-generation cultural-historical activity theory, which drew its inspiration from Leont'ev's work, constituted an advance over Vygotsky's first-generation theory by explicitly articulating the dialectical relation between individual and collective. As part of an effort to develop third-generation-historical activity theory, I propose in this…

  6. An Overview of Cultural Historical Activity Theory (CHAT) Use in Classroom Research 2000 to 2009

    ERIC Educational Resources Information Center

    Nussbaumer, Doris

    2012-01-01

    Western educational researchers have eagerly accepted activity theory (AT) also known as cultural historical activity theory (CHAT) to collect and analyze data in rich description of complex situations. As this theory is applicable to a wide variety of disciplines, this review is limited to education and specifically to qualitative studies of…

  7. Testing a Longitudinal Integrated Self-Efficacy and Self-Determination Theory Model for Physical Activity Post-Cardiac Rehabilitation

    PubMed Central

    Sweet, Shane N.; Fortier, Michelle S.; Strachan, Shaelyn M.; Blanchard, Chris M.; Boulay, Pierre

    2014-01-01

    Self-determination theory and self-efficacy theory are prominent theories in the physical activity literature, and studies have begun integrating their concepts. Sweet, Fortier, Strachan and Blanchard (2012) have integrated these two theories in a cross-sectional study. Therefore, this study sought to test a longitudinal integrated model to predict physical activity at the end of a 4-month cardiac rehabilitation program based on theory, research and Sweet et al.’s cross-sectional model. Participants from two cardiac rehabilitation programs (N=109) answered validated self-report questionnaires at baseline, two and four months. Data were analyzed using Amos to assess the path analysis and model fit. Prior to integration, perceived competence and self-efficacy were combined, and labeled as confidence. After controlling for 2-month physical activity and cardiac rehabilitation site, no motivational variables significantly predicted residual change in 4-month physical activity. Although confidence at two months did not predict residual change in 4-month physical activity, it had a strong positive relationship with 2-month physical activity (β=0.30, P<0.001). The overall model retained good fit indices. In conclusion, results diverged from theoretical predictions of physical activity, but self-determination and self-efficacy theory were still partially supported. Because the model had good fit, this study demonstrated that theoretical integration is feasible. PMID:26973926

  8. Active-Passive-Intuitive Learning Theory: A Unified Theory of Learning and Development

    ERIC Educational Resources Information Center

    Sigette, Tyson

    2009-01-01

    This paper addresses many theories of learning and human development which are very similar with regards as to how they suggest learning occurs. The differences in most of the theories exist in how they treat the development of the learner compared to methods of teaching. Most of the major learning theories taught to educators today are based on…

  9. Microfluidic rheology of active particle suspensions: Kinetic theory.

    PubMed

    Alonso-Matilla, Roberto; Ezhilan, Barath; Saintillan, David

    2016-07-01

    We analyze the effective rheology of a dilute suspension of self-propelled slender particles confined between two infinite parallel plates and subject to a pressure-driven flow. We use a continuum kinetic model to describe the configuration of the particles in the system, in which the disturbance flows induced by the swimmers are taken into account, and use it to calculate estimates of the suspension viscosity for a range of channel widths and flow strengths typical of microfluidic experiments. Our results are in agreement with previous bulk models, and in particular, demonstrate that the effect of activity is strongest at low flow rates, where pushers tend to decrease the suspension viscosity whereas pullers enhance it. In stronger flows, dissipative stresses overcome the effects of activity leading to increased viscosities followed by shear-thinning. The effects of confinement and number density are also analyzed, and our results confirm the apparent transition to superfluidity reported in recent experiments on pusher suspensions at intermediate densities. We also derive an approximate analytical expression for the effective viscosity in the limit of weak flows and wide channels, and demonstrate good agreement between theory and numerical calculations. PMID:27375827

  10. Dynamical theory of active cellular response to external stress.

    PubMed

    De, Rumi; Safran, Samuel A

    2008-09-01

    We present a comprehensive, theoretical treatment of the orientational response to external stress of active, contractile cells embedded in a gel-like elastic medium. The theory includes both the forces that arise from the deformation of the matrix as well as forces due to the internal regulation of the stress fibers and focal adhesions of the cell. We calculate the time-dependent response of both the magnitude and the direction of the elastic dipole that characterizes the active forces exerted by the cell, for various situations. For static or quasistatic external stress, cells orient parallel to the stress while for high frequency dynamic external stress, cells orient nearly perpendicular. Both numerical and analytical calculations of these effects are presented. In addition we predict the relaxation time for the cellular response for both slowly and rapidly varying external stresses; several characteristic scaling regimes for the relaxation time as a function of applied frequency are predicted. We also treat the case of cells for which the regulation of the stress fibers and focal adhesions is controlled by strain (instead of stress) and show that the predicted dependence of the cellular orientation on the Poisson ratio of the matrix can differentiate strain vs stress regulation of cellular response. PMID:18851081

  11. Dynamical theory of active cellular response to external stress

    NASA Astrophysics Data System (ADS)

    de, Rumi; Safran, Samuel A.

    2008-09-01

    We present a comprehensive, theoretical treatment of the orientational response to external stress of active, contractile cells embedded in a gel-like elastic medium. The theory includes both the forces that arise from the deformation of the matrix as well as forces due to the internal regulation of the stress fibers and focal adhesions of the cell. We calculate the time-dependent response of both the magnitude and the direction of the elastic dipole that characterizes the active forces exerted by the cell, for various situations. For static or quasistatic external stress, cells orient parallel to the stress while for high frequency dynamic external stress, cells orient nearly perpendicular. Both numerical and analytical calculations of these effects are presented. In addition we predict the relaxation time for the cellular response for both slowly and rapidly varying external stresses; several characteristic scaling regimes for the relaxation time as a function of applied frequency are predicted. We also treat the case of cells for which the regulation of the stress fibers and focal adhesions is controlled by strain (instead of stress) and show that the predicted dependence of the cellular orientation on the Poisson ratio of the matrix can differentiate strain vs stress regulation of cellular response.

  12. Information Security Analysis Using Game Theory and Simulation

    SciTech Connect

    Schlicher, Bob G; Abercrombie, Robert K

    2012-01-01

    Information security analysis can be performed using game theory implemented in dynamic simulations of Agent Based Models (ABMs). Such simulations can be verified with the results from game theory analysis and further used to explore larger scale, real world scenarios involving multiple attackers, defenders, and information assets. Our approach addresses imperfect information and scalability that allows us to also address previous limitations of current stochastic game models. Such models only consider perfect information assuming that the defender is always able to detect attacks; assuming that the state transition probabilities are fixed before the game assuming that the players actions are always synchronous; and that most models are not scalable with the size and complexity of systems under consideration. Our use of ABMs yields results of selected experiments that demonstrate our proposed approach and provides a quantitative measure for realistic information systems and their related security scenarios.

  13. Accounting for Errors in Model Analysis Theory: A Numerical Approach

    NASA Astrophysics Data System (ADS)

    Sommer, Steven R.; Lindell, Rebecca S.

    2004-09-01

    By studying the patterns of a group of individuals' responses to a series of multiple-choice questions, researchers can utilize Model Analysis Theory to create a probability distribution of mental models for a student population. The eigenanalysis of this distribution yields information about what mental models the students possess, as well as how consistently they utilize said mental models. Although the theory considers the probabilistic distribution to be fundamental, there exists opportunities for random errors to occur. In this paper we will discuss a numerical approach for mathematically accounting for these random errors. As an example of this methodology, analysis of data obtained from the Lunar Phases Concept Inventory will be presented. Limitations and applicability of this numerical approach will be discussed.

  14. Using activity-based costing and theory of constraints to guide continuous improvement in managed care.

    PubMed

    Roybal, H; Baxendale, S J; Gupta, M

    1999-01-01

    Activity-based costing and the theory of constraints have been applied successfully in many manufacturing organizations. Recently, those concepts have been applied in service organizations. This article describes the application of activity-based costing and the theory of constraints in a managed care mental health and substance abuse organization. One of the unique aspects of this particular application was the integration of activity-based costing and the theory of constraints to guide process improvement efforts. This article describes the activity-based costing model and the application of the theory of constraint's focusing steps with an emphasis on unused capacities of activities in the organization. PMID:10350791

  15. Small Molecule Activation by Constrained Phosphorus Compounds: Insights from Theory.

    PubMed

    Pal, Amrita; Vanka, Kumar

    2016-01-19

    An exciting new development in main group chemistry has been the use of a constrained, "flat", phosphorus-based complex to mediate in reactions such as the dehydrogenation of ammonia borane (AB), and the activation of the N-H bond in primary amines. Its importance is based on the fact that it shows that main group compounds, when properly designed, can be as effective as transition metal complexes for doing significant chemical transformations. What the current computational study, employing density functional theory (DFT), reveals is that a common, general mechanism exists that accounts for the behavior of the flat phosphorus compound in the different reactions that have been experimentally reported to date. This mechanism, which involves the mediation by a base as a proton transfer agent, is simpler and energetically more favorable than the previous mechanisms that have been proposed for the same reactions in the literature. It is likely that the knowledge gained from the current work about the chemical behavior of this phosphorus compound can be utilized to design new constrained phosphorus-based compounds. PMID:26700074

  16. Solar Activity Predictions Based on Solar Dynamo Theories

    NASA Astrophysics Data System (ADS)

    Schatten, Kenneth H.

    2009-05-01

    We review solar activity prediction methods, statistical, precursor, and recently the Dikpati and the Choudhury groups’ use of numerical flux-dynamo methods. Outlining various methods, we compare precursor techniques with weather forecasting. Precursors involve events prior to a solar cycle. First started by the Russian geomagnetician Ohl, and then Brown and Williams; the Earth's field variations near solar minimum was used to predict the next solar cycle, with a correlation of 0.95. From the standpoint of causality, as well as energetically, these relationships were somewhat bizarre. One index used was the "number of anomalous quiet days,” an antiquated, subjective index. Scientific progress cannot be made without some suspension of disbelief; otherwise old paradigms become tautologies. So, with youthful naïveté, Svalgaard, Scherrer, Wilcox and I viewed the results through rose-colored glasses and pressed ahead searching for understanding. We eventually fumbled our way to explaining how the Sun could broadcast the state of its internal dynamo to Earth. We noted one key aspect of the Babcock-Leighton Flux Dynamo theory: the polar field at the end of a cycle serves as a seed for the next cycle's growth. Near solar minimum this field usually bathes the Earth, and thereby affects geomagnetic indices then. We found support by examining 8 previous solar cycles. Using our solar precursor technique we successfully predicted cycles 21, 22 and 23 using WSO and MWSO data. Pesnell and I improved the method using a SODA (SOlar Dynamo Amplitude) Index. In 2005, nearing cycle 23's minimum, Svalgaard and I noted an unusually weak polar field, and forecasted a small cycle 24. We discuss future advances: the flux-dynamo methods. As far as future solar activity, I shall let the Sun decide; it will do so anyhow.

  17. Lyapunov analysis: from dynamical systems theory to applications

    NASA Astrophysics Data System (ADS)

    Cencini, Massimo; Ginelli, Francesco

    2013-06-01

    [17], von Neumann [18], Krylov [19]3 and Asonov and Sinai [20] on ergodic theory. Lyapunov exponents quantify exponential sensitivity to initial conditions and provide direct access to the entropy production in ergodic systems via the Pesin theory [21]. Further advances have been made possible by the introduction of proper physical invariant measures for certain dissipative systems due to Sinai [22], Ruelle [23] and Bowen [24, 25]. However, it was necessary to wait until the end of the 1970s before the independent works of Shimada and Nagashima [26] and Benettin et al [27] introduced the numerical algorithms required to compute Lyapunov exponents beyond the largest one. The availability of such algorithms and also, at about the same time, of those necessary for the computation of fractal dimensions and entropies by Grassberger and Procaccia [28], made possible the study of chaotic behavior in physically relevant models. Lyapunov analysis, applied to experimental systems [29], was also made possible by a combination of these numerical methods with ideas from nonlinear time series analysis [30]. As a result, it is nowadays widely recognized that Lyapunov exponents are a central tool of chaos theory, crucial for characterizing a number of interesting physical properties including dynamical entropies and fractal dimensions [31]. Their pivotal role in modern dynamical systems theory has been established by a fruitful exchange between a rigorous (and beautiful) mathematical theory and the algorithmic approaches essential for understanding many physical phenomena. From the 1990s to the present, with the concomitant progress in both theoretical understanding and computer capabilities, there has been a progressive shift of interest from low dimensional towards high dimensional systems. This shift towards dynamics characterized by many degrees of freedom, possibly spatially organized and/or with several characteristic temporal scales, has been accompanied by the need for

  18. Understanding Synchronous Computer-Mediated Classroom Discussion through Cultural-Historical Activity Theory

    ERIC Educational Resources Information Center

    Park, Yangjoo

    2015-01-01

    This study is about graduate students' discourse practices in classroom text-based synchronous computer mediated discussions (SCMD). Cultural historical activity theory (in short, Activity Theory) is the primary theoretical lens through which the data are analyzed. Engeström's (1987) Activity System model among the various theoretical positions or…

  19. Activity Theory as a Framework for Designing the Model of College English Listening

    ERIC Educational Resources Information Center

    Zhang, Jianfeng

    2014-01-01

    Activity theory signifies that activities are at the centre of human behaviour and it has been used to study cognitive process in many fields. Nowadays, college English listening learning is time-consuming but less effective in China, so enhancing the performance of listening instruction is a very hot topic. Theoretically, activity theory is able…

  20. Decision Engines for Software Analysis Using Satisfiability Modulo Theories Solvers

    NASA Technical Reports Server (NTRS)

    Bjorner, Nikolaj

    2010-01-01

    The area of software analysis, testing and verification is now undergoing a revolution thanks to the use of automated and scalable support for logical methods. A well-recognized premise is that at the core of software analysis engines is invariably a component using logical formulas for describing states and transformations between system states. The process of using this information for discovering and checking program properties (including such important properties as safety and security) amounts to automatic theorem proving. In particular, theorem provers that directly support common software constructs offer a compelling basis. Such provers are commonly called satisfiability modulo theories (SMT) solvers. Z3 is a state-of-the-art SMT solver. It is developed at Microsoft Research. It can be used to check the satisfiability of logical formulas over one or more theories such as arithmetic, bit-vectors, lists, records and arrays. The talk describes some of the technology behind modern SMT solvers, including the solver Z3. Z3 is currently mainly targeted at solving problems that arise in software analysis and verification. It has been applied to various contexts, such as systems for dynamic symbolic simulation (Pex, SAGE, Vigilante), for program verification and extended static checking (Spec#/Boggie, VCC, HAVOC), for software model checking (Yogi, SLAM), model-based design (FORMULA), security protocol code (F7), program run-time analysis and invariant generation (VS3). We will describe how it integrates support for a variety of theories that arise naturally in the context of the applications. There are several new promising avenues and the talk will touch on some of these and the challenges related to SMT solvers. Proceedings

  1. Sociological Understandings of Conduct for a Noncanonical Activity Theory: Exploring Intersections and Complementarities

    ERIC Educational Resources Information Center

    Sawchuk, Peter H.; Stetsenko, Anna

    2008-01-01

    Following a discussion of activity theory as an approach to human development originally rooted in transformational change, we review the historical context and diverse conceptualizations of social conduct from the field of sociology. The discussion of social conduct is broken into theories of social action, theories of enactment, and contemporary…

  2. The Bourgeoisie Dream Factory: Teaching Marx's Theory of Alienation through an Experiential Activity

    ERIC Educational Resources Information Center

    Windsor, Elroi J.; Carroll, Alana M.

    2015-01-01

    Effectively teaching sociological theories to undergraduate students is challenging. Students often enroll in theory courses due to major requirements, not personal interest. Consequently, many students approach the study of theory with anxiety. This study examined the effectiveness of an experiential learning activity designed to teach Karl…

  3. Using Cultural-Historical Activity Theory to Design and Evaluate an Educational Game in Science Education

    ERIC Educational Resources Information Center

    Lazarou, D.

    2011-01-01

    The aim of this paper is to describe a methodology for using Cultural-Historical Activity Theory (CHAT) at the initial stages of the design process of an educational game, by exploring how the theory can be used as a framework for producing not only usable but also useful computer tools. The research also aimed to investigate how the theory could…

  4. Participation in Peer Response as Activity: An Examination of Peer Response Stances from an Activity Theory Perspective

    ERIC Educational Resources Information Center

    Zhu, Wei; Mitchell, Deborah A.

    2012-01-01

    This article reports a case study that examined English as a Second Language students' peer response stances from an activity theory perspective. More specifically, the study was guided by the constructs of activity and motive/object in Leont'ev's theory. Multiple sources of data were collected from two native Spanish-speaking students enrolled in…

  5. Checking the determinants of physical activity based on the theory of planned behavior in the housewives

    PubMed Central

    Saber, Fatemeh; Shanazi, Hossein; Sharifirad, Gholamreza; Hasanzadeh, Akbar

    2014-01-01

    Background: Sedentary life has been recognized as a serious problem in today's Iranian society. Promoting the lifestyle with increased physical activity and prevention of cardiovascular disease (CVD) is imperative. The purpose of this study was identifying the determinants of physical activity in the housewives of Nain city in 2012 based on the theory of planned behavior. Materials and Methods: In this cross-sectional study, 120 housewives were selected by simple random sampling method. Data collection tool was a questionnaire designed based on a standardized and fabricated questionnaire and consisted of four parts. The questionnaire included awareness variables, theory of structures, planned behavior, and physical activity. Data analysis was performed using the SPSS software version 18 and associated statistical tests. Findings: The 120 housewives under study had a mean age of 34.58 ± 6.86 years. The mean scores of awareness, attitude, motivation to perform, subjective norms, and perceived behavioral control variables were 74.1 ± 18.5, 82.6 ± 12.1, 59.4 ± 21.7, 63.2 ± 21.2, and 48.1 ± 12.9 respectively. There was a significant relationship between the motivation for physical activity among women and knowledge (P = 0.02) attitude (P = 0.04) subjective norms (P = 0.002) perceived behavioral control (P = 0.001), and physical activity (P = 0.04). Conclusions: It seems that the housewives, despite being aware of and having a positive attitude on the benefits of physical activity, had a poor lifestyle. Perhaps further studies can help in finding the causes of this issue and the barriers to physical activity such as the conditions and plan for greater measures for improving physical activity, in order to promote women's health which has a significant role in family and community health. PMID:25250360

  6. Analysis of cylindrical Langmuir probe using experiment and different theories

    SciTech Connect

    Hassouba, M. A.; Galaly, A. R.; Rashed, U. M.

    2013-03-15

    Cylindrical probe data have been analyzed using different theories in order to determine some plasma parameters (electron temperature and electron and ion densities). Langmuir probe data are obtained in a cylindrical DC glow discharge in the positive column plasma at argon gas pressures varied from 0.5 to 6 Torr and at constant discharge current equal to 10 mA. The electron density has calculated from the electron current at the space potential and from Orbital Motion Limited (OML) collisionless theory. Ion density has obtained from the OML analysis of the ion saturation currents. In addition, the electron temperature has measured by three different methods using probe and electrons currents. The electron temperature T{sub e}, plasma density n{sub e}, and space potential V{sub s}, have been obtained from the measured single cylindrical probe I-V characteristic curves. The radial distribution of the electron temperature and plasma density along the glow discharge are measured and discussed. Using the collisionless theories by Langmuir cylindrical probe and up to several Torr argon gas pressures the differences between the values of electron temperature and electron and ion densities stay within reasonable error limits.

  7. Expanding the Foci of Activity Theory: Accessing the Broader Contexts and Experiences of Mathematics Education Reform

    ERIC Educational Resources Information Center

    Venkat, Hamsa; Adler, Jill

    2008-01-01

    In this paper, we consider our use of activity theory to examine empirical data from a study of reform in England--the implementation of the mathematics strand of the Key Stage 3 Strategy in two schools. Our concerns are largely methodological--we consider the aspects of reform that more traditional activity theory methods and foci were able to…

  8. Online Asynchronous Threaded Discussions: Good Enough to Advance Students through the Proximal Zone of Activity Theory?

    ERIC Educational Resources Information Center

    Maurino, Paula San Millan

    2007-01-01

    This paper presents a study which involved researching student interaction and participation under the lens of Activity Theory and Social Computing. Activity Theory is a philosophical framework that integrates the objective, the sociocultural, and the ecological, while Social Computing describes any type of computing application in which software…

  9. Applications of surface analysis and surface theory in tribology

    NASA Technical Reports Server (NTRS)

    Ferrante, John

    1989-01-01

    Tribology, the study of adhesion, friction and wear of materials, is a complex field which requires a knowledge of solid state physics, surface physics, chemistry, material science, and mechanical engineering. It has been dominated, however, by the more practical need to make equipment work. With the advent of surface analysis and advances in surface and solid-state theory, a new dimension has been added to the analysis of interactions at tribological interfaces. In this paper the applications of tribological studies and their limitations are presented. Examples from research at the NASA Lewis Research Center are given. Emphasis is on fundamental studies involving the effects of monolayer coverage and thick films on friction and wear. A summary of the current status of theoretical calculations of defect energetics is presented. In addition, some new theoretical techniques which enable simplified quantitative calculations of adhesion, fracture, and friction are discussed.

  10. Applications of surface analysis and surface theory in tribology

    NASA Technical Reports Server (NTRS)

    Ferrante, John

    1988-01-01

    Tribology, the study of adhesion, friction and wear of materials is a complex field which requires a knowledge of solid state physics, surface physics, chemistry, material science and mechanical engineering. It has been dominated, however, by the more practical need to make equipment work. With the advent of surface analysis and advances in surface and solid state theory, a new dimension has been added to the analysis of interactions at tribological interfaces. In this paper the applications of tribological studies and their limitations are presented. Examples from research at the NASA Lewis Research Center are given. Emphasis is on fundamental studies involving the effects of monolayer coverage and thick films on friction and wear. A summary of the current status of theoretical calculations of defect energetics is presented. In addition, some new theoretical techniques which enable simplified quantitative calculations of adhesion, fracture and friction are discussed.

  11. Theory and application of experimental model analysis in earthquake engineering

    NASA Astrophysics Data System (ADS)

    Moncarz, P. D.

    The feasibility and limitations of small-scale model studies in earthquake engineering research and practice is considered with emphasis on dynamic modeling theory, a study of the mechanical properties of model materials, the development of suitable model construction techniques and an evaluation of the accuracy of prototype response prediction through model case studies on components and simple steel and reinforced concrete structures. It is demonstrated that model analysis can be used in many cases to obtain quantitative information on the seismic behavior of complex structures which cannot be analyzed confidently by conventional techniques. Methodologies for model testing and response evaluation are developed in the project and applications of model analysis in seismic response studies on various types of civil engineering structures (buildings, bridges, dams, etc.) are evaluated.

  12. Hamiltonian analysis of higher derivative scalar-tensor theories

    NASA Astrophysics Data System (ADS)

    Langlois, David; Noui, Karim

    2016-07-01

    We perform a Hamiltonian analysis of a large class of scalar-tensor Lagrangians which depend quadratically on the second derivatives of a scalar field. By resorting to a convenient choice of dynamical variables, we show that the Hamiltonian can be written in a very simple form, where the Hamiltonian and the momentum constraints are easily identified. In the case of degenerate Lagrangians, which include the Horndeski and beyond Horndeski quartic Lagrangians, our analysis confirms that the dimension of the physical phase space is reduced by the primary and secondary constraints due to the degeneracy, thus leading to the elimination of the dangerous Ostrogradsky ghost. We also present the Hamiltonian formulation for nondegenerate theories and find that they contain four degrees of freedom, including a ghost, as expected. We finally discuss the status of the unitary gauge from the Hamiltonian perspective.

  13. Probability theory versus simulation of petroleum potential in play analysis

    USGS Publications Warehouse

    Crovelli, R.A.

    1987-01-01

    An analytic probabilistic methodology for resource appraisal of undiscovered oil and gas resources in play analysis is presented. This play-analysis methodology is a geostochastic system for petroleum resource appraisal in explored as well as frontier areas. An objective was to replace an existing Monte Carlo simulation method in order to increase the efficiency of the appraisal process. Underlying the two methods is a single geologic model which considers both the uncertainty of the presence of the assessed hydrocarbon and its amount if present. The results of the model are resource estimates of crude oil, nonassociated gas, dissolved gas, and gas for a geologic play in terms of probability distributions. The analytic method is based upon conditional probability theory and a closed form solution of all means and standard deviations, along with the probabilities of occurrence. ?? 1987 J.C. Baltzer A.G., Scientific Publishing Company.

  14. Blogs and Social Network Sites as Activity Systems: Exploring Adult Informal Learning Process through Activity Theory Framework

    ERIC Educational Resources Information Center

    Heo, Gyeong Mi; Lee, Romee

    2013-01-01

    This paper uses an Activity Theory framework to explore adult user activities and informal learning processes as reflected in their blogs and social network sites (SNS). Using the assumption that a web-based space is an activity system in which learning occurs, typical features of the components were investigated and each activity system then…

  15. Exact WKB analysis of {N} = 2 gauge theories

    NASA Astrophysics Data System (ADS)

    Ashok, Sujay K.; Jatkar, Dileep P.; John, Renjan R.; Raman, M.; Troost, Jan

    2016-07-01

    We study {N} = 2 supersymmetric gauge theories with gauge group SU(2) coupled to fundamental flavours, covering all asymptotically free and conformal cases. We re-derive, from the conformal field theory perspective, the differential equations satisfied by ɛ 1- and ɛ 2-deformed instanton partition functions. We confirm their validity at leading order in ɛ 2 via a saddle-point analysis of the partition function. In the semi-classical limit we show that these differential equations take a form amenable to exact WKB analysis. We compute the monodromy group associated to the differential equations in terms of ɛ 1-deformed and Borel resummed Seiberg-Witten data. For each case, we study pairs of Stokes graphs that are related by flips and pops, and show that the monodromy groups allow one to confirm the Stokes automorphisms that arise as the phase of ɛ 1 is varied. Finally, we relate the Borel resummed monodromies with the traditional Seiberg-Witten variables in the semi-classical limit.

  16. Inference algorithms and learning theory for Bayesian sparse factor analysis

    NASA Astrophysics Data System (ADS)

    Rattray, Magnus; Stegle, Oliver; Sharp, Kevin; Winn, John

    2009-12-01

    Bayesian sparse factor analysis has many applications; for example, it has been applied to the problem of inferring a sparse regulatory network from gene expression data. We describe a number of inference algorithms for Bayesian sparse factor analysis using a slab and spike mixture prior. These include well-established Markov chain Monte Carlo (MCMC) and variational Bayes (VB) algorithms as well as a novel hybrid of VB and Expectation Propagation (EP). For the case of a single latent factor we derive a theory for learning performance using the replica method. We compare the MCMC and VB/EP algorithm results with simulated data to the theoretical prediction. The results for MCMC agree closely with the theory as expected. Results for VB/EP are slightly sub-optimal but show that the new algorithm is effective for sparse inference. In large-scale problems MCMC is infeasible due to computational limitations and the VB/EP algorithm then provides a very useful computationally efficient alternative.

  17. Nodal equivalence theory for hexagonal geometry, thermal reactor analysis

    SciTech Connect

    Zika, M.; Downar, T. )

    1992-01-01

    An important aspect of advanced nodal methods is the determination of equivalent few-group parameters for the relatively large homogenized regions used in the nodal flux solution. The theoretical foundation for light water reactor (LWR) assembly homogenization methods has been clearly established, and during the last several years, its successes have secured its position in the stable of dependable LWR analysis methods. Groupwise discontinuity factors that correct for assembly homogenization errors are routinely generated along with the group constants during lattice physics analysis. During the last several years, there has been interest in applying equivalence theory to other reactor types and other geometries. A notable effort has been the work at Argonne National Laboratory to incorporate nodal equivalence theory (NET) for hexagonal lattices into the nodal diffusion option of the DIF3D code. This work was originally intended to improve the neutronics methods used for the analysis of the Experimental Breeder Reactor II (EBR-II), and Ref. 4 discusses the success of that application. More recently, however, attempts were made to apply NET to advanced, thermal reactor designs such as the modular high-temperature gas reactor (MHTGR) and the new production heavy water reactor (NPR/HWR). The same methods that were successful for EBR-II have encountered problems for these reactors. Our preliminary analysis indicates that the sharp global flux gradients in these cores requires large discontinuity factors (greater than 4 or 5) to reproduce the reference solution. This disrupts the convergence of the iterative methods used to solve for the node-wise flux moments and partial currents. Several attempts to remedy the problem have been made over the last few years, including bounding the discontinuity factors and providing improved initial guesses for the flux solution, but nothing has been satisfactory.

  18. General Theory for Integrated Analysis of Growth, Gene, and Protein Expression in Biofilms

    PubMed Central

    Zhang, Tianyu; Pabst, Breana; Klapper, Isaac; Stewart, Philip S.

    2013-01-01

    A theory for analysis and prediction of spatial and temporal patterns of gene and protein expression within microbial biofilms is derived. The theory integrates phenomena of solute reaction and diffusion, microbial growth, mRNA or protein synthesis, biomass advection, and gene transcript or protein turnover. Case studies illustrate the capacity of the theory to simulate heterogeneous spatial patterns and predict microbial activities in biofilms that are qualitatively different from those of planktonic cells. Specific scenarios analyzed include an inducible GFP or fluorescent protein reporter, a denitrification gene repressed by oxygen, an acid stress response gene, and a quorum sensing circuit. It is shown that the patterns of activity revealed by inducible stable fluorescent proteins or reporter unstable proteins overestimate the region of activity. This is due to advective spreading and finite protein turnover rates. In the cases of a gene induced by either limitation for a metabolic substrate or accumulation of a metabolic product, maximal expression is predicted in an internal stratum of the biofilm. A quorum sensing system that includes an oxygen-responsive negative regulator exhibits behavior that is distinct from any stage of a batch planktonic culture. Though here the analyses have been limited to simultaneous interactions of up to two substrates and two genes, the framework applies to arbitrarily large networks of genes and metabolites. Extension of reaction-diffusion modeling in biofilms to the analysis of individual genes and gene networks is an important advance that dovetails with the growing toolkit of molecular and genetic experimental techniques. PMID:24376726

  19. Lay theories of successful aging after the death of a spouse: a network text analysis of bereavement advice.

    PubMed

    Bergstrom, M J; Holmes, M E

    2000-01-01

    Social theories of successful aging attempt to explain how individuals adapt to changes characteristically associated with aging and to predict whether older adults' adaptations will lead to successful aging. The death of a spouse and the accompanying bereavement process entail dramatic changes to personal networks and experience to which individuals must adapt to age successfully. Network text analysis (including word frequencies, cluster analysis, and multidimensional scaling) of advice for adjusting to, and coping with, the loss of a spouse given by a sample of 60 bereaved spouses (mean age = 68) at 6 points in time after the death of their marital partner (3-4 weeks to 24 months) reveal respondents' lay theories of successful aging. Thematic clusters address social positioning and qualifiers, activity, communication, time, and spousal characteristics. Results indicate respondents frame their advice as unique to their context of social relationships while providing support for activity theory and negatively addressing disengagement theory. PMID:11063287

  20. Physical basis for prompt-neutron activation analysis

    SciTech Connect

    Chrien, R.E.

    1982-01-01

    The technique called prompt ..gamma..-ray neutron activation analysis has been applied to rapid materials analysis. The radiation following the neutron radiation capture is prompt in the sense that the nuclear decay time is on the order of 10/sup -15/ second, and thus the technique is not strictly activation, but should be called radiation neutron capture spectroscopy or neutron capture ..gamma..-ray spectroscopy. This paper reviews the following: sources and detectors, theory of radiative capture, nonstatistical capture, giant dipole resonance, fast neutron capture, and thermal neutron capture ..gamma..-ray spectra. 14 figures.

  1. INCORPORATING ROUTINE ACTIVITIES, ACTIVITY SPACES, AND SITUATIONAL DEFINITIONS INTO THE SOCIAL SCHEMATIC THEORY OF CRIME*

    PubMed Central

    BARR, ASHLEY B.; LEI, MAN-KIT; STEWART, ERIC

    2014-01-01

    Simons and Burt’s (2011) social schematic theory (SST) of crime posits that adverse social factors are associated with offending because they promote a set of social schemas (i.e., a criminogenic knowledge structure) that elevates the probability of situational definitions favorable to crime. This study extends the SST model by incorporating the role of contexts for action. Furthermore, the study advances tests of the SST by incorporating a measure of criminogenic situational definitions to assess whether such definitions mediate the effects of schemas and contexts on crime. Structural equation models using 10 years of panel data from 582 African American youth provided strong support for the expanded theory. The results suggest that childhood and adolescent social adversity fosters a criminogenic knowledge structure as well as selection into criminogenic activity spaces and risky activities, all of which increase the likelihood of offending largely through situational definitions. Additionally, evidence shows that the criminogenic knowledge structure interacts with settings to amplify the likelihood of situational definitions favorable to crime. PMID:26392633

  2. Using Activity Theory to Understand the Contradictions in an Online Transatlantic Collaboration between Student-Teachers of English as a Foreign Language

    ERIC Educational Resources Information Center

    Antoniadou, Victoria

    2011-01-01

    This article describes the contradictions reported by student-teachers in Barcelona who engaged in telecollaboration with transatlantic peers via Second Life, during their initial training in Teaching English as a Foreign Language. The data analysis draws upon Grounded Theory and is theoretically informed by Activity Theory and the notion of…

  3. Active Learning with Monty Hall in a Game Theory Class

    ERIC Educational Resources Information Center

    Brokaw, Alan J.; Merz, Thomas E.

    2004-01-01

    The authors describe a game that students can play on the first day of a game theory class. The game introduces the 4 essential elements of any game and is designed so that its sequel, also played on the first day of class, has students playing the well-known Monty Hall game, which raises the question: Should you switch doors? By implementing a…

  4. Do Differences in Brain Activation Challenge Universal Theories of Dyslexia?

    ERIC Educational Resources Information Center

    Ziegler, Johannes C.

    2006-01-01

    It has been commonly agreed that developmental dyslexia in different languages has a common biological origin: a dysfunction of left posterior temporal brain regions dealing with phonological processes. Siok, Perfetti, Jin, and Tan (2004, "Nature," 431, 71-76) challenge this biological unity theory of dyslexia: Chinese dyslexics show no deficits…

  5. Aerodynamic preliminary analysis system 2. Part 1: Theory

    NASA Technical Reports Server (NTRS)

    Bonner, E.; Clever, W.; Dunn, K.

    1981-01-01

    A subsonic/supersonic/hypersonic aerodynamic analysis was developed by integrating the Aerodynamic Preliminary Analysis System (APAS), and the inviscid force calculation modules of the Hypersonic Arbitrary Body Program. APAS analysis was extended for nonlinear vortex forces using a generalization of the Polhamus analogy. The interactive system provides appropriate aerodynamic models for a single input geometry data base and has a run/output format similar to a wind tunnel test program. The user's manual was organized to cover the principle system activities of a typical application, geometric input/editing, aerodynamic evaluation, and post analysis review/display. Sample sessions are included to illustrate the specific task involved and are followed by a comprehensive command/subcommand dictionary used to operate the system.

  6. Theory, Investigation and Stability of Cathode Electrocatalytic Activity

    SciTech Connect

    Ding, Dong; Liu, Mingfei; Lai, Samson; Blinn, Kevin; Liu, Meilin

    2012-09-30

    conditions. This was also confirmed by x-ray analyses. For example, soft x-ray XANES data reveal that Co cations displace the Mn cations as being more favored to be reduced. Variations in the Sr-O in the annealed LSCF Fourier-transformed (FT) EXAFS suggest that some Sr segregation is occurring, but is not present in the annealed LSM-infiltrated LSCF cathode materials. Further, a surface enhanced Raman technique was also developed into to probe and map LSM and LSCF phase on underlying YSZ substrate, enabling us to capture important chemical information of cathode surfaces under practical operating conditions. Electrochemical models for the design of test cells and understanding of mechanism have been developed for the exploration of fundamental properties of electrode materials. Novel catalyst coatings through particle depositions (SDC, SSC, and LCC) or continuous thin films (PSM and PSCM) were successfully developed to improve the activity and stability of LSCF cathodes. Finally, we have demonstrated enhanced activity and stability of LSCF cathodes over longer periods of time in homemade and commercially available cells by an optimized LSM infiltration process. Microstructure examination of the tested cells did not show obvious differences between blank and infiltrated cells, suggesting that the infiltrated LSM may form a coherent film on the LSCF cathodes. There was no significant change in the morphology or microstructure of the LSCF cathode due to the structural similarity of LSCF and LSM. Raman analysis of the tested cells indicated small peaks emerging on the blank cells that correspond to trace amounts of secondary phase formation during operation (e.g., CoO{sub x}). The formation of this secondary phase might be attributed to performance degradation. In contrast, there was no such secondary phase observed in the LSM infiltrated cells, indicating that the LSM modification staved off secondary phase formation and thus improved the stability.

  7. Applicability of Complexity Theory to Martian Fluvial Systems: A Preliminary Analysis

    NASA Technical Reports Server (NTRS)

    Rosenshein, E. B.

    2003-01-01

    In the last 15 years, terrestrial geomorphology has been revolutionized by the theories of chaotic systems, fractals, self-organization, and selforganized criticality. Except for the application of fractal theory to the analysis of lava flows and rampart craters on Mars, these theories have not yet been applied to problems of Martian landscape evolution. These complexity theories are elucidated below, along with the methods used to relate these theories to the realities of Martian fluvial systems.

  8. Lyapunov analysis: from dynamical systems theory to applications

    NASA Astrophysics Data System (ADS)

    Cencini, Massimo; Ginelli, Francesco

    2013-06-01

    [17], von Neumann [18], Krylov [19]3 and Asonov and Sinai [20] on ergodic theory. Lyapunov exponents quantify exponential sensitivity to initial conditions and provide direct access to the entropy production in ergodic systems via the Pesin theory [21]. Further advances have been made possible by the introduction of proper physical invariant measures for certain dissipative systems due to Sinai [22], Ruelle [23] and Bowen [24, 25]. However, it was necessary to wait until the end of the 1970s before the independent works of Shimada and Nagashima [26] and Benettin et al [27] introduced the numerical algorithms required to compute Lyapunov exponents beyond the largest one. The availability of such algorithms and also, at about the same time, of those necessary for the computation of fractal dimensions and entropies by Grassberger and Procaccia [28], made possible the study of chaotic behavior in physically relevant models. Lyapunov analysis, applied to experimental systems [29], was also made possible by a combination of these numerical methods with ideas from nonlinear time series analysis [30]. As a result, it is nowadays widely recognized that Lyapunov exponents are a central tool of chaos theory, crucial for characterizing a number of interesting physical properties including dynamical entropies and fractal dimensions [31]. Their pivotal role in modern dynamical systems theory has been established by a fruitful exchange between a rigorous (and beautiful) mathematical theory and the algorithmic approaches essential for understanding many physical phenomena. From the 1990s to the present, with the concomitant progress in both theoretical understanding and computer capabilities, there has been a progressive shift of interest from low dimensional towards high dimensional systems. This shift towards dynamics characterized by many degrees of freedom, possibly spatially organized and/or with several characteristic temporal scales, has been accompanied by the need for

  9. Co-Analysis of Work in the Triadic Supervision of Preservice Teachers Based on Neo-Vygotskian Activity Theory: Case Study from a French University Institute of Teacher Training

    ERIC Educational Resources Information Center

    Cartaut, Solange; Bertone, Stefano

    2009-01-01

    The goal of this study was to evaluate the effects of the joint training activities of a cooperating teacher and a university supervisor during an advisory visit on (a) the professional development of a preservice teacher's activity and (b) the reorganization of mentoring activity following this visit. The results are considered from a theoretical…

  10. Using behavioural activation in the treatment of depression: a control theory perspective.

    PubMed

    McEvoy, P; Law, A; Bates, R; Hylton, K; Mansell, W

    2013-12-01

    Behavioural activation is an intervention that can be used to counteract the typical patterns of withdrawal, avoidance and inactivity that characterize depression. This paper examines the processes of change that may occur during behavioural activation from the perspective of control theory. Some of the key concepts that are associated with control theory are introduced and the process of change that may occur during behavioural activation is illustrated using two case studies. The case studies provide anecdotal evidence which supports the hypothesis that the effective implementation of behavioural activation may depend upon clients being able to retain or regain the sense of control that they value. The differences between a control-theory-based approach and more orthodox behavioural and cognitive approaches are highlighted and the implications of these differences are discussed. Flexible approaches that are informed by control theory, may offer a useful alternative to the more established behavioural and cognitive approaches towards behavioural activation. PMID:23240823

  11. Induced starburst and nuclear activity: Faith, facts, and theory

    NASA Technical Reports Server (NTRS)

    Shlosman, Isaac

    1990-01-01

    The problem of the origin of starburst and nuclear (nonstellar) activity in galaxies is reviewed. A physical understanding of the mechanism(s) that induce both types of activity requires one to address the following issues: (1) what is the source of fuel that powers starbursts and active galactic nuclei; and (2) how is it channeled towards the central regions of host galaxies? As a possible clue, the author examines the role of non-axisymmetric perturbations of galactic disks and analyzes their potential triggers. Global gravitational instabilities in the gas on scales approx. 100 pc appear to be crucial for fueling the active galactic nuclei.

  12. Critical Theory & Textual Arguments: Expanding Habermas's Analysis of Literary Claims.

    ERIC Educational Resources Information Center

    Stroud, Scott R.

    Jurgen Habermas's theory of communicative action has held much promise for critical theory and its examination of the structure of society. This theory, however, has been accused by some as being limited in regard to other forms of discourse, especially fictional, mythical, and religious texts. Habermas has argued that literature (i.e., fictive…

  13. Technology and the Analysis of a Political Theory.

    ERIC Educational Resources Information Center

    Weaver, Gary R.

    1988-01-01

    Discussed is the value of integrating the study of technology and society. Topics include political theory of spontaneous social orders, paradoxical nature of the theory in historical and in contemporary contexts, uses of spontaneous order theory with feedback technologies, and the comparison of feedback technology with two different spontaneous…

  14. Total body nitrogen analysis. [neutron activation analysis

    NASA Technical Reports Server (NTRS)

    Palmer, H. E.

    1975-01-01

    Studies of two potential in vivo neutron activation methods for determining total and partial body nitrogen in animals and humans are described. A method using the CO-11 in the expired air as a measure of nitrogen content was found to be adequate for small animals such as rats, but inadequate for human measurements due to a slow excretion rate. Studies on the method of measuring the induced N-13 in the body show that with further development, this method should be adequate for measuring muscle mass changes occurring in animals or humans during space flight.

  15. Socio-Cultural Context for Online Learning: A Case Study Viewed from Activity Theory Perspective

    ERIC Educational Resources Information Center

    Liu, Xiaojing

    2004-01-01

    The complexities of digital age pose challenge to existing instruction technology theory as it applies to a distance learning environment. Through the lens of Activity Theory, this study takes a broad picture of an online course and examines the socio-cultural factors affecting the success of a distance course as well as their complex…

  16. Job Search and Social Cognitive Theory: The Role of Career-Relevant Activities

    ERIC Educational Resources Information Center

    Zikic, Jelena; Saks, Alan M.

    2009-01-01

    Social cognitive theory was used to explain the relationships between career-relevant activities (environmental and self career exploration, career resources, and training), self-regulatory variables (job search self-efficacy and job search clarity), variables from the Theory of Planned Behavior (job search attitude, subjective norm, job search…

  17. Presenting Theoretical Ideas Prior to Inquiry Activities Fosters Theory-Level Knowledge

    ERIC Educational Resources Information Center

    Wecker, Christof; Rachel, Alexander; Heran-Dörr, Eva; Waltner, Christine; Wiesner, Hartmut; Fischer, Frank

    2013-01-01

    In the course of inquiry activities similar to those of real scientists, learners are supposed to develop knowledge both on the level of observable phenomena and on the level of explanatory theories. However, some theories involve theoretical entities (e.g., "Weiss domains") that cannot be observed directly and therefore may be hard to…

  18. Development and Evaluation of a Theory-Based Physical Activity Guidebook for Breast Cancer Survivors

    ERIC Educational Resources Information Center

    Vallance, Jeffrey K.; Courneya, Kerry S.; Taylor, Lorian M.; Plotnikoff, Ronald C.; Mackey, John R.

    2008-01-01

    This study's objective was to develop and evaluate the suitability and appropriateness of a theory-based physical activity (PA) guidebook for breast cancer survivors. Guidebook content was constructed based on the theory of planned behavior (TPB) using salient exercise beliefs identified by breast cancer survivors in previous research. Expert…

  19. Cultural-Historical Activity Theory: Vygotsky's Forgotten and Suppressed Legacy and Its Implication for Mathematics Education

    ERIC Educational Resources Information Center

    Roth, Wolff-Michael

    2012-01-01

    Cultural-historical activity theory--with historical roots in dialectical materialism and the social psychology to which it has given rise--has experienced exponential growth in its acceptance by scholars interested in understanding knowing and learning writ large. In education, this theory has constituted something like a well kept secret that is…

  20. Changing Investment in Activities and Interests in Elders' Lives: Theory and Measurement

    ERIC Educational Resources Information Center

    Adams, Kathryn Betts

    2004-01-01

    Socioemotional selectivity and gerotranscendence, newer theories with roots in the disengagement theory of aging, provided the theoretical framework for a new measure of perceived change in investment in a variety of pursuits. The 30-item Change in Activity and Interest Index (CAII) was given to a sample of 327 outpatients aged 65-94. Items with…

  1. Gambler Risk Perception: A Mental Model and Grounded Theory Analysis.

    PubMed

    Spurrier, Michael; Blaszczynski, Alexander; Rhodes, Paul

    2015-09-01

    Few studies have investigated how gamblers perceive risk or the role of risk perception in disordered gambling. The purpose of the current study therefore was to obtain data on lay gamblers' beliefs on these variables and their effects on decision-making, behaviour, and disordered gambling aetiology. Fifteen regular lay gamblers (non-problem/low risk, moderate risk and problem gamblers) completed a semi-structured interview following mental models and grounded theory methodologies. Gambler interview data was compared to an expert 'map' of risk-perception, to identify comparative gaps or differences associated with harmful or safe gambling. Systematic overlapping processes of data gathering and analysis were used to iteratively extend, saturate, test for exception, and verify concepts and themes emerging from the data. The preliminary findings suggested that gambler accounts supported the presence of expert conceptual constructs, and to some degree the role of risk perception in protecting against or increasing vulnerability to harm and disordered gambling. Gambler accounts of causality, meaning, motivation, and strategy were highly idiosyncratic, and often contained content inconsistent with measures of disordered gambling. Disordered gambling appears heavily influenced by relative underestimation of risk and overvaluation of gambling, based on explicit and implicit analysis, and deliberate, innate, contextual, and learned processing evaluations and biases. PMID:24402720

  2. Effective field theory of dark energy: a dynamical analysis

    SciTech Connect

    Frusciante, Noemi; Raveri, Marco; Silvestri, Alessandra E-mail: mraveri@sissa.it

    2014-02-01

    The effective field theory (EFT) of dark energy relies on three functions of time to describe the dynamics of background cosmology. The viability of these functions is investigated here by means of a thorough dynamical analysis. While the system is underdetermined, and one can always find a set of functions reproducing any expansion history, we are able to determine general compatibility conditions for these functions by requiring a viable background cosmology. In particular, we identify a set of variables that allows us to transform the non-autonomous system of equations into an infinite-dimensional one characterized by a significant recursive structure. We then analyze several autonomous sub-systems, obtained truncating the original one at increasingly higher dimension, that correspond to increasingly general models of dark energy and modified gravity. Furthermore, we exploit the recursive nature of the system to draw some general conclusions on the different cosmologies that can be recovered within the EFT formalism and the corresponding compatibility requirements for the EFT functions. The machinery that we set up serves different purposes. It offers a general scheme for performing dynamical analysis of dark energy and modified gravity models within the model independent framework of EFT; the general results, obtained with this technique, can be projected into specific models, as we show in one example. It also can be used to determine appropriate ansätze for the three EFT background functions when studying the dynamics of cosmological perturbations in the context of large scale structure tests of gravity.

  3. Implicit theories about willpower predict the activation of a rest goal following self-control exertion.

    PubMed

    Job, Veronika; Bernecker, Katharina; Miketta, Stefanie; Friese, Malte

    2015-10-01

    Past research indicates that peoples' implicit theories about the nature of willpower moderate the ego-depletion effect. Only people who believe or were led to believe that willpower is a limited resource (limited-resource theory) showed lower self-control performance after an initial demanding task. As of yet, the underlying processes explaining this moderating effect by theories about willpower remain unknown. Here, we propose that the exertion of self-control activates the goal to preserve and replenish mental resources (rest goal) in people with a limited-resource theory. Five studies tested this hypothesis. In Study 1, individual differences in implicit theories about willpower predicted increased accessibility of a rest goal after self-control exertion. Furthermore, measured (Study 2) and manipulated (Study 3) willpower theories predicted an increased preference for rest-conducive objects. Finally, Studies 4 and 5 provide evidence that theories about willpower predict actual resting behavior: In Study 4, participants who held a limited-resource theory took a longer break following self-control exertion than participants with a nonlimited-resource theory. Longer resting time predicted decreased rest goal accessibility afterward. In Study 5, participants with an induced limited-resource theory sat longer on chairs in an ostensible product-testing task when they had engaged in a task requiring self-control beforehand. This research provides consistent support for a motivational shift toward rest after self-control exertion in people holding a limited-resource theory about willpower. PMID:26075793

  4. Activity Theories and the Ontology of Psychology: Learning from Danish and Russian Experiences.

    PubMed

    Mammen, Jens; Mironenko, Irina

    2015-12-01

    Psychology has permanent problems of theoretical coherence and practical, analytic and critical efficiency. It is claimed that Activity Theory (AT) with roots in a long European philosophical tradition and continued in Russian AT is a first step to remedy this. A Danish version of AT may have a key to exceed some, mostly implicit, ontological restrictions in traditional AT and free it from an embracement of functionalism and mechanicism, rooted in Renaissance Physics. The analysis goes back to Aristotle's understanding of the freely moving animal in its ecology and introduces some dualities in the encounter between subject and object which replace the dualistic dichotomies traditionally splitting Psychology in Naturwissenschaft vs. Geisteswissenshaft. This also implies a "Copernican turn" of Cartesian dualism. The perspectives are to give place for a phenomenology of meaning without cutting human psyche out of Nature and to open Psychology to its domain. PMID:26001990

  5. IMMAN: free software for information theory-based chemometric analysis.

    PubMed

    Urias, Ricardo W Pino; Barigye, Stephen J; Marrero-Ponce, Yovani; García-Jacas, César R; Valdes-Martiní, José R; Perez-Gimenez, Facundo

    2015-05-01

    The features and theoretical background of a new and free computational program for chemometric analysis denominated IMMAN (acronym for Information theory-based CheMoMetrics ANalysis) are presented. This is multi-platform software developed in the Java programming language, designed with a remarkably user-friendly graphical interface for the computation of a collection of information-theoretic functions adapted for rank-based unsupervised and supervised feature selection tasks. A total of 20 feature selection parameters are presented, with the unsupervised and supervised frameworks represented by 10 approaches in each case. Several information-theoretic parameters traditionally used as molecular descriptors (MDs) are adapted for use as unsupervised rank-based feature selection methods. On the other hand, a generalization scheme for the previously defined differential Shannon's entropy is discussed, as well as the introduction of Jeffreys information measure for supervised feature selection. Moreover, well-known information-theoretic feature selection parameters, such as information gain, gain ratio, and symmetrical uncertainty are incorporated to the IMMAN software ( http://mobiosd-hub.com/imman-soft/ ), following an equal-interval discretization approach. IMMAN offers data pre-processing functionalities, such as missing values processing, dataset partitioning, and browsing. Moreover, single parameter or ensemble (multi-criteria) ranking options are provided. Consequently, this software is suitable for tasks like dimensionality reduction, feature ranking, as well as comparative diversity analysis of data matrices. Simple examples of applications performed with this program are presented. A comparative study between IMMAN and WEKA feature selection tools using the Arcene dataset was performed, demonstrating similar behavior. In addition, it is revealed that the use of IMMAN unsupervised feature selection methods improves the performance of both IMMAN and WEKA

  6. Analysis of active renin heterogeneity.

    PubMed

    Katz, S A; Malvin, R L; Lee, J; Kim, S H; Murray, R D; Opsahl, J A; Abraham, P A

    1991-09-01

    Active renin is a heterogeneous enzyme that can be separated into multiple forms with high-resolution isoelectric focusing. The isoelectric heterogeneity may result from differences in glycosylation between the different forms. In order to determine the relationship between active renin heterogeneity and differences in composition or attachment of oligosaccharides, two separate experiments were performed: (i) Tunicamycin, which interferes with normal glycosylation processing, increased the proportion of relatively basic renin forms secreted into the incubation media by rat renal cortical slices. (ii) Endoglycosidase F, which enzymatically removes carbohydrate from some classes of glycoprotein, similarly increased the proportion of relatively basic forms when incubated with active human recombinant renin. In addition, further studies with inhibitors of human renin activity revealed that the heterogeneous renin forms were similarly inhibited by two separate renin inhibitors. These results are consistent with the hypothesis that renin isoelectric heterogeneity is due in part to differences in carbohydrate moiety attachment and that the heterogeneity of renin does not influence access of direct renin inhibitors to the active site of renin. PMID:1908097

  7. Conference on Instrumental Activation Analysis: IAA 89

    NASA Astrophysics Data System (ADS)

    Vobecky, M.; Obrusnik, I.

    1989-05-01

    The proceedings contain 40 abstracts of papers all of which have been incorporated in INIS. The papers were centred on the applications of radioanalytical methods, especially on neutron activation analysis, x ray fluorescence analysis, PIXE analysis and tracer techniques in biology, medicine and metallurgy, measuring instruments including microcomputers, and data processing methods.

  8. Primer Vector Optimization: Survey of Theory, new Analysis and Applications

    NASA Astrophysics Data System (ADS)

    Guzman

    This paper presents a preliminary study in developing a set of optimization tools for orbit rendezvous, transfer and station keeping. This work is part of a large scale effort undergoing at NASA Goddard Space Flight Center and a.i. solutions, Inc. to build generic methods, which will enable missions with tight fuel budgets. Since no single optimization technique can solve efficiently all existing problems, a library of tools where the user could pick the method most suited for the particular mission is envisioned. The first trajectory optimization technique explored is Lawden's primer vector theory [Ref. 1]. Primer vector theory can be considered as a byproduct of applying Calculus of Variations (COV) techniques to the problem of minimizing the fuel usage of impulsive trajectories. For an n-impulse trajectory, it involves the solution of n-1 two-point boundary value problems. In this paper, we look at some of the different formulations of the primer vector (dependent on the frame employed and on the force model). Also, the applicability of primer vector theory is examined in effort to understand when and why the theory can fail. Specifically, since COV is based on "small variations", singularities in the linearized (variational) equations of motion along the arcs must be taken into account. These singularities are a recurring problem in analyzes that employ "small variations" [Refs. 2, 3]. For example, singularities in the (2-body problem) variational equations along elliptic arcs occur when [Ref. 4], 1) the difference between the initial and final times is a multiple of the reference orbit period, 2) the difference between the initial and final true anomalies are given by k, for k= 0, 1, 2, 3,..., note that this cover the 3) the time of flight is a minimum for the given difference in true anomaly. For the N-body problem, the situation is more complex and is still under investigation. Several examples, such as the initialization of an orbit (ascent trajectory) and

  9. Implicit theories of the body among college women: implications for physical activity.

    PubMed

    Lyons, Claire; Kaufman, Annette R; Rima, Brandi

    2015-09-01

    This study explored the relationship between implicit theories of the body (ITB) and self-reported physical activity. ITB are beliefs about the malleability of the body. Individuals may hold entity ITB (that body appearance is fixed) or incremental ITB (that body appearance can be changed). Female undergraduate students (N = 313) completed an online survey assessing ITB, physical activity, and discrepancy between actual and ideal body weight. Participants endorsing incremental ITB reported more physical activity. A significant ITB by weight discrepancy interaction emerged. Developing interventions targeting implicit theories of the body may be one way to increase physical activity. PMID:24271689

  10. The Effectiveness of WhatsApp Mobile Learning Activities Guided by Activity Theory on Students' Knowledge Management

    ERIC Educational Resources Information Center

    Barhoumi, Chokri

    2015-01-01

    This research paper explores the effectiveness of using mobile technologies to support a blended learning course titled Scientific Research Methods in Information Science. Specifically, it discusses the effects of WhatsApp mobile learning activities guided by activity theory on students' knowledge Management (KM). During the 2014 academic year,…

  11. A surrealistic mega-analysis of redisorganization theories

    PubMed Central

    Oxman, Andrew D; Sackett, David L; Chalmers, Iain; Prescott, Trine E

    2005-01-01

    Background We are sick and tired of being redisorganized. Objective To systematically review the empirical evidence for organizational theories and repeated reorganizations. Methods We did not find anything worth reading, other than Dilbert, so we fantasized. Unfortunately, our fantasies may well resemble many people's realities. We are sorry about this, but it is not our fault. Results We discovered many reasons for repeated reorganizations, the most common being ‘no good reason’. We estimated that trillions of dollars are being spent on strategic and organizational planning activities each year, thus providing lots of good reasons for hundreds of thousands of people, including us, to get into the business. New leaders who are intoxicated with the prospect of change further fuel perpetual cycles of redisorganization. We identified eight indicators of successful redisorganizations, including large consultancy fees paid to friends and relatives. Conclusions We propose the establishment of ethics committees to review all future redisorganization proposals in order to put a stop to uncontrolled, unplanned experimentation inflicted on providers and users of the health services. PMID:16319441

  12. Activity Theory and the Transformation of Pedagogic Practice

    ERIC Educational Resources Information Center

    Yamazumi, Katsuhiro

    2006-01-01

    Today, work and other societal practices are experiencing accelerating paradigm shifts from mass-production-based systems toward new systems based on networking between organizations, collaboration, and partnerships. This shift requires new paradigms in the fields of education, learning, and development. As human activity quickly changes to…

  13. A Conceptual Framework Based on Activity Theory for Mobile CSCL

    ERIC Educational Resources Information Center

    Zurita, Gustavo; Nussbaum, Miguel

    2007-01-01

    There is a need for collaborative group activities that promote student social interaction in the classroom. Handheld computers interconnected by a wireless network allow people who work on a common task to interact face to face while maintaining the mediation afforded by a technology-based system. Wirelessly interconnected handhelds open up new…

  14. Quantum Theory, Active Information and the Mind-Matter Problem

    NASA Astrophysics Data System (ADS)

    Pylkkänen, Paavo

    Bohm and Hiley suggest that a certain new type of active information plays a key objective role in quantum processes. This chapter discusses the implications of this suggestion to our understanding of the relation between the mental and the physical aspects of reality.

  15. Exploring Formative Assessment Using Cultural Historical Activity Theory

    ERIC Educational Resources Information Center

    Asghar, Mandy

    2013-01-01

    Formative assessment is a pedagogic practice that has been the subject of much research and debate, as to how it can be used most effectively to deliver enhanced student learning in the higher education setting. Often described as a complex concept it embraces activities that range from facilitating students understanding of assessment standards,…

  16. Institutionalizing Retention Activity: Toward a Theory-Based Model.

    ERIC Educational Resources Information Center

    Saunders, Martha Dunagin

    2003-01-01

    Examines Appreciative Inquiry, a relatively new approach to organizational change and growth, as a method for institutionalizing retention activity. Results of a case study in a college of arts and sciences suggest the method to be effective in creating a shared vision for the organization, energized participants, improved morale, and increased…

  17. Analysis of Cavity Volumes in Proteins Using Percolation Theory

    NASA Astrophysics Data System (ADS)

    Green, Sheridan; Jacobs, Donald; Farmer, Jenny

    Molecular packing is studied in a diverse set of globular proteins in their native state ranging in size from 34 to 839 residues An new algorithm has been developed that builds upon the classic Hoshen-Kopelman algorithm for site percolation combined with a local connection criterion that classifies empty space within a protein as a cavity when large enough to hold a spherical shaped probe of radius, R, otherwise a microvoid. Although microvoid cannot fit an object (e.g. molecule or ion) that is the size of the probe or larger, total microvoid volume is a major contribution to protein volume. Importantly, the cavity and microvoid classification depends on probe radius. As probe size decreases, less microvoid forms in favor of more cavities. As probe size is varied from large to small, many disconnected cavities merge to form a percolating path. For fixed probe size, microvoid, cavity and solvent accessible boundary volume properties reflect conformational fluctuations. These results are visualized on three-dimensional structures. Analysis of the cluster statistics within the framework of percolation theory suggests interconversion between microvoid and cavity pathways regulate the dynamics of solvent penetration during partial unfolding events important to protein function.

  18. Activity Theory and Qualitative Research in Digital Domains

    ERIC Educational Resources Information Center

    Sam, Cecile

    2012-01-01

    Understanding the interactions between people, computer-mediated communication, and online life requires that researchers appropriate a set of methodological tools that would be best suited for capturing and analyzing the phenomenon. However, these tools are not limited to relevant technological forms of data collections and analysis programs; it…

  19. An analysis of the Belinfante-Swihart theory of gravity

    NASA Technical Reports Server (NTRS)

    Lee, D. L.; Lightman, A. P.

    1972-01-01

    The Belinfante-Swihart (BS) theory is reformulated in a representation in which uncharged matter responds to gravity in the same way as in metric theories. The BS gravitationally modified Maxwell equations are also put into metric form to first order in the deviations of the physical metric from flat space, but not to second order; consequently the theory is nonmetric except in first order. Also shown is that the theory violates the high precision Eotvos-Dicke experiment, but cannot be ruled out by the gravitational precession of gyroscopes.

  20. Catalytic activity of nuclease P1: Experiment and theory

    SciTech Connect

    Miller, J.H.; Falcone, J.M.; Shibata, M.; Box, H.C.

    1994-10-01

    Nuclease P1 from Penicillium citrinum is a zinc dependent glyco-enzyme that recognizes single stranded DNA and RNA as substrates and hydrolyzes the phosphate ester bond. Nuclease Pl seems to recognize particular conformations of the phosphodiester backbone and shows significant variation in the rate of hydrolytic activity depending upon which nucleosides are coupled by the phosphodiester bond. The efficiency of nuclease Pl in hydrolyzing the phosphodiester bonds of a substrate can be altered by modifications to one of the substrate bases induced by ionizing radiation or oxidative stress. Measurements have been made of the effect of several radiation induced lesions on the catalytic rate of nuclease Pl. A model of the structure of the enzyme has been constructed in order to better understand the binding and activity of this enzyme on various ssDNA substrates.

  1. A Biomimetic Propulsor for Active Noise Control. Part 2: Theory

    NASA Astrophysics Data System (ADS)

    Annaswamy Krol, A., Jr.; Bandyopadhyay, P. R.

    2000-11-01

    The alteration of radiated noise in underwater propulsors using biomimetic active control is considered. Wake momentum filling is carried out by introducing artificial muscles at the trailing edge of a stator blade of an upstream stator propulsor, and articulating them like a fish tail (see companion abstract Part 1). Using a systems framework, we derive a methodology for the articulation of the muscles with active control. The unsteady force produced on the rotor because of velocity perturbations due to actuator displacements, wake deficits caused by stator boundary layers, and blade rotation is modeled. Linear and adaptive nonlinear control strategies are described for articulating the tail using unsteady force measurements. This active control procedure can be viewed as the realization of “virtual” blades with different sweep and noise characteristics and can affect the noise spectrum due to direct radiation significantly. The work provides an understanding of the effect of nonuniform wakes on radiated noise and can lead to a general approach by which wakes can be altered.

  2. Apps of Steel: Are Exercise Apps Providing Consumers with Realistic Expectations?: A Content Analysis of Exercise Apps for Presence of Behavior Change Theory

    ERIC Educational Resources Information Center

    Cowan, Logan T.; Van Wagenen, Sarah A.; Brown, Brittany A.; Hedin, Riley J.; Seino-Stephan, Yukiko; Hall, P. Cougar; West, Joshua H.

    2013-01-01

    Objective. To quantify the presence of health behavior theory constructs in iPhone apps targeting physical activity. Methods. This study used a content analysis of 127 apps from Apple's (App Store) "Health & Fitness" category. Coders downloaded the apps and then used an established theory-based instrument to rate each app's inclusion of…

  3. The SMART Theory and Modeling Team: An Integrated Element of Mission Development and Science Analysis

    NASA Technical Reports Server (NTRS)

    Hesse, Michael; Birn, J.; Denton, Richard E.; Drake, J.; Gombosi, T.; Hoshino, M.; Matthaeus, B.; Sibeck, D.

    2005-01-01

    to SMART needs during mission development and science analysis. In this presentation, we will present an overview of SMART theory and modeling team activities. In particular, we will provide examples of science objectives derived from state-of-the art models, and of recent research results that continue to be utilized in SMART mission development.

  4. An Empirical Analysis of the Dual Labor Market Theory.

    ERIC Educational Resources Information Center

    Andrisani, Paul James

    This study focuses upon the process of labor market entry of male youth in the context of the dual labor market theory. Essentially, the dual market theory contends that a large body of workers is involuntarily confined to substandard jobs in a "secondary" labor market which is separated from the mainstream, or "primary" sector by impenetrable…

  5. Principals' Leadership and Teachers' Motivation: Self-Determination Theory Analysis

    ERIC Educational Resources Information Center

    Eyal, Ori; Roth, Guy

    2011-01-01

    Purpose: The purpose of this paper is to investigate the relationship between educational leadership and teacher's motivation. The research described here was anchored in the convergence of two fundamental theories of leadership and motivation: the full range model of leadership and self-determination theory. The central hypotheses were that…

  6. NONDESTRUCTIVE MULTIELEMENT INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS

    EPA Science Inventory

    A nondestructive instrumental neutron activation analysis procedure permitted accurate and sensitive measurement of most elements with atomic numbers between 11 and 92. The sensitivity of the procedure was dependent on each element's intrinsic characteristics and the sample matri...

  7. The origin and evolution of activity analysis.

    PubMed

    Creighton, C

    1992-01-01

    Practitioners of occupational therapy in the early 1900s selected therapeutic activities with an intuitive understanding of their characteristics and operations. The term activity analysis and the methodology for breaking down and examining tasks scientifically, however, were borrowed from industry during World War I. Methods originally used in time and motion study of jobs were applied to vocational retraining and therapeutic crafts; later, they were applied to a broader range of activities. The most systematic early use of activity analysis was in occupational therapy for physical dysfunction, particularly in military hospitals. Development of the concept was gradual until the 1970s, when the delineation of theoretical frames of reference for practice led to important changes. Today, activity analysis is viewed as a multifaceted process that involves both generic and specific components. PMID:1558138

  8. Researching Contradictions: Cultural Historical Activity Theory Research (CHAT) in the English Classroom

    ERIC Educational Resources Information Center

    Thompson, Ian

    2015-01-01

    This article argues that Cultural Historical Activity Theory (CHAT) is an appropriate theoretical and methodological framework for researchers in English interested in the social contexts of culture and its relationship with the formation of mind and activity in the English classroom. Two key concepts in Vygotsky's thought central to understanding…

  9. Brief Report: The Theory of Planned Behaviour Applied to Physical Activity in Young People Who Smoke

    ERIC Educational Resources Information Center

    Everson, Emma S.; Daley, Amanda J.; Ussher, Michael

    2007-01-01

    It has been hypothesised that physical activity may be useful as a smoking cessation intervention for young adults. In order to inform such interventions, this study evaluated the theory of planned behaviour (TPB) for understanding physical activity behaviour in young smokers. Regular smokers aged 16-19 years (N=124), self-reported physical…

  10. Dialogue--Missing in Action Competence: A Cultural Historical Activity Theory Approach in a Botswana School

    ERIC Educational Resources Information Center

    Silo, Nthalivi

    2013-01-01

    An in-depth case study on children's participation in environmental management activities in a primary school in Botswana was undertaken, drawing on cultural historical activity theory (CHAT) and the action competence model. This research revealed that due to a lack of dialogue between teachers and children, teachers tended to view children's…

  11. Exploration of Tensions in a Mobile-Technology Supported Fieldtrip: An Activity Theory Perspective

    ERIC Educational Resources Information Center

    Lai, Chih-Hung; Chen, Fei-Ching; Yang, Jie-Chi

    2014-01-01

    The purpose of this study was to analyze how mobile technologies were incorporated and implemented in an outdoor learning activity. Two classes of primary school students participated in the experiment. Using activity theory as an analytical framework, it is found that underlying tensions provided rich insights into system dynamics and that…

  12. Activity Theory in Information Systems Research and Practice: Theoretical Underpinnings for an Information Systems Development Model

    ERIC Educational Resources Information Center

    Mursu, Anja; Luukkonen, Irmeli; Toivanen, Marika; Korpela, Mikko

    2007-01-01

    Introduction: The purpose of information systems is to facilitate work activities: here we consider how Activity Theory can be applied in information systems development. Method. The requirements for an analytical model for emancipatory, work-oriented information systems research and practice are specified. Previous research work in Activity…

  13. Contradictions between the Virtual and Physical High School Classroom: A Third-Generation Activity Theory Perspective

    ERIC Educational Resources Information Center

    Murphy, Elizabeth; Manzanares, Maria A. Rodriguez

    2008-01-01

    This paper uses a third-generation Activity Theory perspective to gain insight into the contradictions between the activity systems of the physical and virtual high school classroom from the perspective of teachers who had transitioned from one system to the other. Data collection relied on semi-structured interviews conducted with e-teachers as…

  14. Understanding Preschool Emergent Science in a Cultural Historical Context through Activity Theory

    ERIC Educational Resources Information Center

    Sundberg, Bodil; Areljung, Sofie; Due, Karin; Ekström, Kenneth; Ottander, Christina; Tellgren, Britt

    2016-01-01

    The aim of this study is to explore how cultural factors interact with preschool teachers' shaping of activities with science content, and also how Activity Theory (AT) as a theoretical framework can be useful for examining interrelations within preschool systems. Qualitative data was collected from three preschools in the form of guided group…

  15. Using Molecular Modeling in Teaching Group Theory Analysis of the Infrared Spectra of Organometallic Compounds

    ERIC Educational Resources Information Center

    Wang, Lihua

    2012-01-01

    A new method is introduced for teaching group theory analysis of the infrared spectra of organometallic compounds using molecular modeling. The main focus of this method is to enhance student understanding of the symmetry properties of vibrational modes and of the group theory analysis of infrared (IR) spectra by using visual aids provided by…

  16. Dynamical Theory of Activated Processes in Globular Proteins

    NASA Astrophysics Data System (ADS)

    Northrup, Scott H.; Pear, Michael R.; Lee, Chyuan-Yih; McCammon, J. Andrew; Karplus, Martin

    1982-07-01

    A methos is described for calculating the reaction rate in globular proteins of activated processes such as ligand binding or enzymatic catalysis. The method is based on the determination of the probability that the system is in the transition state and of the magnitude of the reactive flux for transition-state systems. An ``umbrella sampling'' simulation procedure is outlined for evaluating the transition-state probability. The reactive flux is obtained from an approach described previously for calculating the dynamics of transition-state trajectories. An application to the rotational isomerization of an aromatic ring in the bovine pancreatic trypsin inhibitor is presented. The results demonstrate the feasibility of calculating rate constants for reactions in proteins and point to the importance of solvent effects for reactions that occur near the protein surface.

  17. Dynamical theory of activated processes in globular proteins.

    PubMed Central

    Northrup, S H; Pear, M R; Lee, C Y; McCammon, J A; Karplus, M

    1982-01-01

    A method is described for calculating the reaction rate in globular proteins of activated processes such as ligand binding or enzymatic catalysis. The method is based on the determination of the probability that the system is in the transition state and of the magnitude of the reactive flux for transition-state systems. An "umbrella sampling" simulation procedure is outlined for evaluating the transition-state probability. The reactive flux is obtained from an approach described previously for calculating the dynamics of transition-state trajectories. An application to the rotational isomerization of an aromatic ring in the bovine pancreatic trypsin inhibitor is presented. The results demonstrate the feasibility of calculating rate constants for reactions in proteins and point to the importance of solvent effects for reactions that occur near the protein surface. PMID:6955788

  18. The importance of behavior theory in control system modeling of physical activity sensor data.

    PubMed

    Riley, William T; Martin, Cesar A; Rivera, Daniel E

    2014-01-01

    Among health behaviors, physical activity has the most extensive record of research using passive sensors. Control systems and other system dynamic approaches have long been considered applicable for understanding human behavior, but only recently has the technology provided the precise and intensive longitudinal data required for these analytic approaches. Although sensors provide intensive data on the patterns and variations of physical activity over time, the influences of these variations are often unmeasured. Health behavior theories provide an explanatory framework of the putative mediators of physical activity changes. Incorporating the intensive longitudinal measurement of these theoretical constructs is critical to improving the fit of control system model of physical activity and for advancing behavioral theory. Theory-based control models also provide guidance on the nature of the controllers which serve as the basis for just-in-time adaptive interventions based on these control system models. PMID:25571577

  19. Activity anorexia: An interplay between basic and applied behavior analysis

    PubMed Central

    Pierce, W. David; Epling, W. Frank; Dews, Peter B.; Estes, William K.; Morse, William H.; Van Orman, Willard; Herrnstein, Richard J.

    1994-01-01

    The relationship between basic research with nonhumans and applied behavior analysis is illustrated by our work on activity anorexia. When rats are fed one meal a day and allowed to run on an activity wheel, they run excessively, stop eating, and die of starvation. Convergent evidence, from several different research areas, indicates that the behavior of these animals and humans who self-starve is functionally similar. A biobehavioral theory of activity anorexia is presented that details the cultural contingencies, behavioral processes, and physiology of anorexia. Diagnostic criteria and a three-stage treatment program for activity-based anorexia are outlined. The animal model permits basic research on anorexia that for practical and ethical reasons cannot be conducted with humans. Thus, basic research can have applied importance. PMID:22478169

  20. Cultural-historical activity theory: Vygotsky's forgotten and suppressed legacy and its implication for mathematics education

    NASA Astrophysics Data System (ADS)

    Roth, Wolff-Michael

    2012-03-01

    Cultural-historical activity theory—with historical roots in dialectical materialism and the social psychology to which it has given rise—has experienced exponential growth in its acceptance by scholars interested in understanding knowing and learning writ large. In education, this theory has constituted something like a well kept secret that is only in the process of gaining larger levels of acceptance. Mathematics educators are only beginning to realise the tremendous advantages that the theory provides over other theories. In this review essay, I articulate the theory as it may relate to the issues that concern mathematics education and educators with a particular focus on the way in which it addresses logical contradictions in existing theories.

  1. Correlates of physical activity and the theory of planned behavior between African American women who are physically active and those who are not.

    PubMed

    Carter-Parker, Kathleen; Edwards, Karethy A; McCleary-Jones, Voncella

    2012-01-01

    Many people have positive intention to engage in physical activity but fail to act. In general, Physical activity (PA) levels among Americans are declining. However, when compared to all other racial groups, middle aged African American women (AAW) have the lowest rate of PA participation. The lack of physical activity has dire illness consequences for AAW Despite significant efforts to increase physical activity to levels that benefit health, the need to understand successful translation of intention to engage in physical activity, attitude, subjective norm, and perceived behavioral control is warranted in order to design theoretically derived culturally tailored interventions to increase physical activity participation among middle aged AAW. Moreover, there is a paucity of studies that use theoretical underpinnings to elucidate the differences between middle aged AAW who are physically active and those who are not physically active. Therefore, the Theory of Planned Behavior's (TPB) measuring the constructs of intention, subjective norm, attitude, and perceived behavioral control was used to guide the design of this study. One-hundred-fifty-three respondents completed the socio-demographic profile, a Theory of Planned Behavior Questionnaire (TPBQ), and the International Physical Activity Questionnaire (IPAQ). The Pearson's Product-Moment Correlation Coefficient indicated the highest correlation between intention and attitude r (137) = .740, p < .001. The correlation between intention and perceived behavior control was r (137) = .546, p < .001; intention and physical activity r (137) = .439, p < .001; attitude and perceived behavior control r (137) = .487, p < .001; and attitude and physical activity r (137) = .429, p < .001 demonstrated a moderately strong positive relationship. Subjective norm and perceived behavior control demonstrate the smallest correlational significance r (137) = .264, p <.001. Multiple regression analysis revealed attitude towards physical

  2. Application of viability theory for road vehicle active safety during cornering manoeuvres

    NASA Astrophysics Data System (ADS)

    Vandanjon, P.-O.; Coiret, A.; Lorino, T.

    2014-02-01

    Viability theory proposes geometric metaphors in addition to classical ordinary differential equation analysis. In this paper, advantages of applying viability theory to road safety domain are presented. The exact issue is to determine if, from an initial state of a vehicle/road/driver system, a soft controls strategy is compatible with a safe driving sequence. The case of a car negotiating a curve is considered. The application of the viability theory to this issue offers the advantage to avoid classical full computing of the system. Instead of that, it consists on verifying that the states and the controls belong to a subset called the viability kernel. The construction and the use of the viability kernel for a vehicle system dynamic is proposed by using support vector machines algorithm. Then, the applicability of this theory is demonstrated through experimental tests. This innovative application of the viability theory to vehicle dynamics with road safety concerns could benefit to robust embedded warning systems.

  3. Neutron Activation Analysis of Water - A Review

    NASA Technical Reports Server (NTRS)

    Buchanan, John D.

    1971-01-01

    Recent developments in this field are emphasized. After a brief review of basic principles, topics discussed include sources of neutrons, pre-irradiation physical and chemical treatment of samples, neutron capture and gamma-ray analysis, and selected applications. Applications of neutron activation analysis of water have increased rapidly within the last few years and may be expected to increase in the future.

  4. Actor-network theory: a tool to support ethical analysis of commercial genetic testing.

    PubMed

    Williams-Jones, Bryn; Graham, Janice E

    2003-12-01

    Social, ethical and policy analysis of the issues arising from gene patenting and commercial genetic testing is enhanced by the application of science and technology studies, and Actor-Network Theory (ANT) in particular. We suggest the potential for transferring ANT's flexible nature to an applied heuristic methodology for gathering empirical information and for analysing the complex networks involved in the development of genetic technologies. Three concepts are explored in this paper--actor-networks, translation, and drift--and applied to the case of Myriad Genetics and their commercial BRACAnalysis genetic susceptibility test for hereditary breast cancer. Treating this test as an active participant in socio-technical networks clarifies the extent to which it interacts with, shapes and is shaped by people, other technologies, and institutions. Such an understanding enables more sophisticated and nuanced technology assessment, academic analysis, as well as public debate about the social, ethical and policy implications of the commercialization of new genetic technologies. PMID:15115034

  5. Analysis of morphological structuring elements generated using adaptive resonance theory

    NASA Astrophysics Data System (ADS)

    Sharpe, John P.; Sungar, Nilgun; Narayanswamy, Ramkumar; Johnson, Kristina M.

    1995-03-01

    In this paper we consider the formation of morphological templates using adaptive resonance theory. We examine the role of object variability and noise on the clustering of different sized objects as a function of the vigilance parameter. We demonstrate that the fuzzy adaptive resonance theory is robust in the presence of noise but that for poor choice of vigilance there is a proliferation of prototypical categories. We apply the technique to detection of abnormal cells in pap smears.

  6. An analysis of possible applications of fuzzy set theory to the actuarial credibility theory

    NASA Technical Reports Server (NTRS)

    Ostaszewski, Krzysztof; Karwowski, Waldemar

    1992-01-01

    In this work, we review the basic concepts of actuarial credibility theory from the point of view of introducing applications of the fuzzy set-theoretic method. We show how the concept of actuarial credibility can be modeled through the fuzzy set membership functions and how fuzzy set methods, especially fuzzy pattern recognition, can provide an alternative tool for estimating credibility.

  7. Synthesis, Density Functional Theory (DFT), Urease Inhibition and Antimicrobial Activities of 5-Aryl Thiophenes Bearing Sulphonylacetamide Moieties.

    PubMed

    Noreen, Mnaza; Rasool, Nasir; Gull, Yasmeen; Zubair, Muhammad; Mahmood, Tariq; Ayub, Khurshid; Nasim, Faiz-Ul-Hassan; Yaqoob, Asma; Zia-Ul-Haq, Muhammad; de Feo, Vincenzo

    2015-01-01

    A variety of novel 5-aryl thiophenes 4a-g containing sulphonylacetamide (sulfacetamide) groups were synthesized in appreciable yields via Pd[0] Suzuki cross coupling reactions. The structures of these newly synthesized compounds were determined using spectral data and elemental analysis. Density functional theory (DFT) studies were performed using the B3LYP/6-31G (d, p) basis set to gain insight into their structural properties. Frontier molecular orbital (FMOs) analysis of all compounds 4a-g was computed at the same level of theory to get an idea about their kinetic stability. The molecular electrostatic potential (MEP) mapping over the entire stabilized geometries of the molecules indicated the reactive sites. First hyperpolarizability analysis (nonlinear optical response) were simulated at the B3LYP/6-31G (d, p) level of theory as well. The compounds were further evaluated for their promising antibacterial and anti-urease activities. In this case, the antibacterial activities were estimated by the agar well diffusion method, whereas the anti-urease activities of these compounds were determined using the indophenol method by quantifying the evolved ammonia produced. The results revealed that all the sulfacetamide derivatives displayed antibacterial activity against Bacillus subtiles, Escherichia coli, Staphylococcus aureus, Shigella dysenteriae, Salmonella typhae, Pseudomonas aeruginosa at various concentrations. Furthermore, the compound 4g N-((5-(4-chlorophenyl)thiophen-2-yl)sulfonyl) acetamide showed excellent urease inhibition with percentage inhibition activity ~46.23 ± 0.11 at 15 µg/mL with IC50 17.1 µg/mL. Moreover, some other compounds 4a-f also exhibited very good inhibition against urease enzyme. PMID:26556326

  8. The application of spatial analysis based on rough set theory and hierarchical analysis

    NASA Astrophysics Data System (ADS)

    Lin, Zhiyong; Liang, Shuang

    2009-10-01

    As the development of the theory and technology of geographical information, Geographical Information System (GIS) has been widely applied in variety of industries. It usually refers to the analytical problem of multi-factor in GIS thematic application. In this field, the determination of factors' weight is a common and important problem. It actually deals the data when processing the spatial analysis applying GIS, for example, according to the importance of some factor, assign some value to it then process spatial overlay operation using the values and finally conclude some evaluation or result. In reality, there are many factors that affect the some kind of evaluation. Usually, we choose several more important factors as the evaluation criterion in order to make convenient for research. Then we assign some weight values to these factors and process spatial analysis then conclude some decision or evaluation to make support for decision-making. We can choose the factors that can make more impaction on the evaluation or decision-making using the method of Analytical Hierarchy Process (AHP). However, it has strong subjectivity of the factors' weight values assigned by this method. Rough set theory, which can effectively remove the impaction made by artificial factors, can make up the deficiency. It can make the spatial analysis more objective and more effective combining the two methods in GIS spatial analysis.

  9. Physical activity status of academic professors during their early career transition: an application of the theory of planned behavior.

    PubMed

    Kirk, Megan A; Rhodes, Ryan E

    2012-01-01

    Life-transitions (e.g. parenthood) have been linked to physical inactivity, yet the topic requires further exploration. In this study, we evaluated changes in the physical activity (PA) of adults during their early career transition using retrospective analysis and the theory of planned behavior. Recruitment from January to March 2010 yielded a random sample of 267 assistant professors, ages 25-44, employed within the last five years. Repeated measures analysis of variance (RM ANOVA) concluded that PA declined across the transition (d = 0.36-0.43) and was further attenuated by marriage, work hours, and parenthood status. Discriminant function analysis (DFA) identified specific behavioral and control correlates about PA enjoyment, limited time, inconsistent schedule, work demands, and job pressures to distinguish between those who remained active from those who did not across the transition. PA interventions administered prior to career transitions may be needed to prevent physical inactivity. PMID:22348598

  10. Relational frame theory: A new paradigm for the analysis of social behavior

    PubMed Central

    Roche, Bryan; Barnes-Holmes, Yvonne; Barnes-Holmes, Dermot; Stewart, Ian; O'Hora, Denis

    2002-01-01

    Recent developments in the analysis of derived relational responding, under the rubric of relational frame theory, have brought several complex language and cognitive phenomena within the empirical reach of the experimental analysis of behavior. The current paper provides an outline of relational frame theory as a new approach to the analysis of language, cognition, and complex behavior more generally. Relational frame theory, it is argued, also provides a suitable paradigm for the analysis of a wide variety of social behavior that is mediated by language. Recent empirical evidence and theoretical interpretations are provided in support of the relational frame approach to social behavior. PMID:22478379

  11. Protopopov's ideas on habit formation and their relation to the Pavlovian theory of higher nervous activity.

    PubMed

    Windholz, G

    1999-01-01

    In 1929 Viktor P. Protopopov began to replicate E. L. Thorndike's animal experiments on habit acquisition. To determine the conditions necessary for habit formation, Protopopov used the natural experiment method, in which dogs encountered environments that prevented them from reaching a stimulus-bait. Not all dogs acquired the behavior necessary for obtaining the bait. Explaining the results within the framework of the Pavlovian theory of higher nervous activity, Protopopov concluded that habits were acquired when an active animal provoked by a bait-stimulus encountered an environmental barrier. The dogs tried a series of phylogenetic behaviors until the stimulus-bait was reached. The latter movements were retained, forming an ontogenetic habit. The dogs also learned not to produce the unsuccessful movements. In accord with the Pavlovian theory, individual differences in habit formation were related to temperament types. A critique of the Thorndikian Law of Effect is provided in terms of the Pavlovian theory of higher nervous activity. PMID:10696273

  12. Kinetics of Hydrogen Radical Reactions with Toluene Including Chemical Activation Theory Employing System-Specific Quantum RRK Theory Calibrated by Variational Transition State Theory.

    PubMed

    Bao, Junwei Lucas; Zheng, Jingjing; Truhlar, Donald G

    2016-03-01

    Pressure-dependent reactions are ubiquitous in combustion and atmospheric chemistry. We employ a new calibration procedure for quantum Rice-Ramsperger-Kassel (QRRK) unimolecular rate theory within a chemical activation mechanism to calculate the pressure-falloff effect of a radical association with an aromatic ring. The new theoretical framework is applied to the reaction of H with toluene, which is a prototypical reaction in the combustion chemistry of aromatic hydrocarbons present in most fuels. Both the hydrogen abstraction reactions and the hydrogen addition reactions are calculated. Our system-specific (SS) QRRK approach is adjusted with SS parameters to agree with multistructural canonical variational transition state theory with multidimensional tunneling (MS-CVT/SCT) at the high-pressure limit. The new method avoids the need for the usual empirical estimations of the QRRK parameters, and it eliminates the need for variational transition state theory calculations as a function of energy, although in this first application we do validate the falloff curves by comparing SS-QRRK results without tunneling to multistructural microcanonical variational transition state theory (MS-μVT) rate constants without tunneling. At low temperatures, the two approaches agree well with each other, but at high temperatures, SS-QRRK tends to overestimate falloff slightly. We also show that the variational effect is important in computing the energy-resolved rate constants. Multiple-structure anharmonicity, torsional-potential anharmonicity, and high-frequency-mode vibrational anharmonicity are all included in the rate computations, and torsional anharmonicity effects on the density of states are investigated. Branching fractions, which are both temperature- and pressure-dependent (and for which only limited data is available from experiment), are predicted as a function of pressure. PMID:26841076

  13. Visualizing context through theory deconstruction: a content analysis of three bodies of evaluation theory literature.

    PubMed

    Vo, Anne T

    2013-06-01

    While the evaluation field collectively agrees that contextual factors bear on evaluation practice and related scholarly endeavors, the discipline does not yet have an explicit framework for understanding evaluation context. To address this gap in the knowledge base, this paper explores the ways in which evaluation context has been addressed in the practical-participatory, values-engaged, and emergent realist evaluation literatures. Five primary dimensions that constitute evaluation context were identified for this purpose: (1) stakeholder; (2) program; (3) organization; (4) historical/political; and (5) evaluator. Journal articles, book chapters, and conference papers rooted in the selected evaluation approaches were compared along these dimensions in order to explore points of convergence and divergence in the theories. Study results suggest that the selected prescriptive theories most clearly explicate stakeholder and evaluator contexts. Programmatic, organizational, and historical/political contexts, on the other hand, require further clarification. PMID:22469338

  14. Estimation and Psychometric Analysis of Component Profile Scores via Multivariate Generalizability Theory

    ERIC Educational Resources Information Center

    Grochowalski, Joseph H.

    2015-01-01

    Component Universe Score Profile analysis (CUSP) is introduced in this paper as a psychometric alternative to multivariate profile analysis. The theoretical foundations of CUSP analysis are reviewed, which include multivariate generalizability theory and constrained principal components analysis. Because CUSP is a combination of generalizability…

  15. Combining Flux Balance and Energy Balance Analysis for Large-Scale Metabolic Network: Biochemical Circuit Theory for Analysis of Large-Scale Metabolic Networks

    NASA Technical Reports Server (NTRS)

    Beard, Daniel A.; Liang, Shou-Dan; Qian, Hong; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Predicting behavior of large-scale biochemical metabolic networks represents one of the greatest challenges of bioinformatics and computational biology. Approaches, such as flux balance analysis (FBA), that account for the known stoichiometry of the reaction network while avoiding implementation of detailed reaction kinetics are perhaps the most promising tools for the analysis of large complex networks. As a step towards building a complete theory of biochemical circuit analysis, we introduce energy balance analysis (EBA), which compliments the FBA approach by introducing fundamental constraints based on the first and second laws of thermodynamics. Fluxes obtained with EBA are thermodynamically feasible and provide valuable insight into the activation and suppression of biochemical pathways.

  16. The Grammatical Theory of Contrastive Analysis: A New Approach.

    ERIC Educational Resources Information Center

    Anwar, Mohamed Sami

    This work asserts that contrastive analysis should be regarded as a technique of research and not limited to error prediction and material preparation. Introductory observations are made on the state of the field, the domain of contrastive analysis, contrastive analysis and transfer, and contrastive analysis and foreign language instruction. In…

  17. Health Behavior Theory in Popular Calorie Counting Apps: A Content Analysis

    PubMed Central

    Davis, Siena F; Ellsworth, Marisa A; Payne, Hannah E; Hall, Shelby M; Nordhagen, Amber L

    2016-01-01

    Background Although the Health & Fitness category of the Apple App Store features hundreds of calorie counting apps, the extent to which popular calorie counting apps include health behavior theory is unknown. Objective This study evaluates the presence of health behavior theory in calorie counting apps. Methods Data for this study came from an extensive content analysis of the 10 most popular calorie counting apps in the Health & Fitness category of the Apple App Store. Results Each app was given a theory score to reflect the extent to which health behavior theory was integrated into the app. The highest possible score was 60. Out of the 10 apps evaluated, My Diet Coach obtained the highest theory score of 15. MapMyFitness and Yumget received the lowest scores of 0. The average theory score among the apps was 5.6. Conclusions Most of the calorie counting apps in the sample contained minimal health behavior theory. PMID:26935898

  18. An Analysis of Gardner's Theory of Multiple Intelligence.

    ERIC Educational Resources Information Center

    Morgan, Harry

    The theory of multiple intelligence (MI) propounded by Gardner and Hatch suggests that human beings have seven distinct units of intellectual functioning, and that these units are actually separate intelligences with their own observable and measurable abilities. These intelligences were identified as logical-mathematical, linguistic, musical,…

  19. A Conceptual Analysis of Evolutionary Theory for Teacher Education

    ERIC Educational Resources Information Center

    van Dijk, Esther M.; Reydon, Thomas A. C.

    2010-01-01

    In this paper we present a schematic overview of the central concepts in evolutionary theory, setting them off against the background of widespread misconceptions about them. Our aim is to provide high school teachers with (1) an overview of those particular concepts that they can expect students to have difficulties with, (2) a comparison of…

  20. Cluster Analysis for Cognitive Diagnosis: Theory and Applications

    ERIC Educational Resources Information Center

    Chiu, Chia-Yi; Douglas, Jeffrey A.; Li, Xiaodong

    2009-01-01

    Latent class models for cognitive diagnosis often begin with specification of a matrix that indicates which attributes or skills are needed for each item. Then by imposing restrictions that take this into account, along with a theory governing how subjects interact with items, parametric formulations of item response functions are derived and…

  1. The Analysis of a Propositional Logic Game By Ordering Theory

    ERIC Educational Resources Information Center

    Airasian, Peter W.; And Others

    1975-01-01

    A propositional logic game which is a subtest of the new British intelligence scale was analyzed to determine the extent to which skills proper to a single Piagetian period, formal operations, were hierarchically ordered. Item response patterns from 60 14-year-olds were categorized by means of ordering theory, a boolean algebraic measurement…

  2. Environmental Quality Analysis, Theory & Method in the Social Sciences.

    ERIC Educational Resources Information Center

    Kneese, Allen V., Ed.; Bower, Blair T., Ed.

    This book brings together state-of-the-art papers by Resources for the Future staff members and by scholars associated with current programs of environmental quality research. Although some empirical findings are presented, the emphasis is primarily on theory and method. Divided into three parts, the initial section, "The Environment and Economic…

  3. Structural Analysis of the Consumer-Directed Theory of Empowerment.

    ERIC Educational Resources Information Center

    Kosciulek, John F.; Merz, MaryAnn

    2001-01-01

    Tests the hypothesized structural model of the consumer- directed theory of empowerment (CDTE). Participants were 159 consumers with disabilities who were receiving services at a Clubhouse Model community rehabilitation program. Although model respecification was necessary to obtain adequate fit, results provided support for the hypothesized CDTE…

  4. Classical Stasis Theory and the Analysis of Public Policy.

    ERIC Educational Resources Information Center

    Hatch, Gary Layne

    In classical Greece, there was a close tie between rhetoric and the practice and theory of public policy. Gradually, however, rhetoric became increasingly concerned with style and literary criticism, while philosophers began to debate political issues apart from the practical affairs of the polis. Because rhetoric provides a model that can still…

  5. Practical Guide to Conducting an Item Response Theory Analysis

    ERIC Educational Resources Information Center

    Toland, Michael D.

    2014-01-01

    Item response theory (IRT) is a psychometric technique used in the development, evaluation, improvement, and scoring of multi-item scales. This pedagogical article provides the necessary information needed to understand how to conduct, interpret, and report results from two commonly used ordered polytomous IRT models (Samejima's graded…

  6. Grounded Theory and Educational Ethnography: A Methodological Analysis and Critique.

    ERIC Educational Resources Information Center

    Smith, Louis M.; Pohland, Paul A.

    This paper analyzes and evaluates the methodological approach developed by B. G. Glaser and A. L. Strauss in THE DISCOVERY OF GROUNDED THEORY (Chicago: Aldine, 1967). Smith and Pohland's major intent is to raise Glaser and Strauss' most significant concepts and issues, analyze them in the context of seven of their own studies, and in conclusion…

  7. Time Series Analysis of Alternative Media Effects Theories.

    ERIC Educational Resources Information Center

    Watt, James H., Jr.; van den Berg, Sjef A.

    A study was conducted in the Washington, D.C., area to test mass media effects in a community controversy. Five possible theories were hypothesized to explain the effects media have on a community: indirect and direct effects, null effects, agenda setting, reverse effects, and reverse agenda setting. During the 16-month test period of the British…

  8. Organizational Theory Applied to School Reform: A Critical Analysis

    ERIC Educational Resources Information Center

    Bonner, Mike; Koch, Tom; Langmeyer, Daniel

    2004-01-01

    Organizational change in education, as manifested by school reform, is indeed complex. In this article, we describe our experience with organizational change and analyse it using organizational change theories common in education. An evaluation of the reform initiative yielded unexpected problems related to sustainability. As a result, this…

  9. Conformational analysis of cellobiose by electronic structure theories

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adiabatic phi/psi maps for cellobiose were prepared with B3LYP density functional theory. A mixed basis set was used for minimization, followed with 6-31+G(d) single-point calculations, with and without SMD continuum solvation. Different arrangements of the exocyclic groups (3starting geometries) we...

  10. Theory-Based Interventions in Physical Activity: A Systematic Review of Literature in Iran

    PubMed Central

    Abdi, Jalal; Eftekhar, Hassan; Estebsari, Fatemeh; Sadeghi, Roya

    2015-01-01

    Lack of physical activity is ranked fourth among the causes of human death and chronic diseases. Using models and theories to design, implement, and evaluate the health education and health promotion interventions has many advantages. Using models and theories of physical activity, we decided to systematically study the educational and promotional interventions carried out in Iran from 2003 to 2013.Three information databases were used to systematically select papers using key words including Iranian Magazine Database (MAGIRAN), Iran Medical Library (MEDLIB), and Scientific Information Database (SID). Twenty papers were selected and studied. Having been applied in 9 studies, The Trans Theoretical Model (TTM) was the most widespread model in Iran (PENDER in 3 studies, BASNEF in 2, and the Theory of Planned Behavior in 2 studies). With regards to the educational methods, almost all studies used a combination of methods. The most widely used Integrative educational method was group discussion. Only one integrated study was done. Behavior maintenance was not addressed in 75% of the studies. Almost all studies used self-reporting instruments. The effectiveness of educational methods was assessed in none of the studies. Most of the included studies had several methodological weaknesses, which hinder the validity and applicability of their results. According to the findings, the necessity of need assessment in using models, epidemiology and methodology consultation, addressing maintenance of physical activity, using other theories and models such as social marketing and social-cognitive theory, and other educational methods like empirical and complementary are suggested. PMID:25948454

  11. Theory-based interventions in physical activity: a systematic review of literature in Iran.

    PubMed

    Abdi, Jalal; Eftekhar, Hassan; Estebsari, Fatemeh; Sadeghi, Roya

    2015-01-01

    Lack of physical activity is ranked fourth among the causes of human death and chronic diseases. Using models and theories to design, implement, and evaluate the health education and health promotion interventions has many advantages. Using models and theories of physical activity, we decided to systematically study the educational and promotional interventions carried out in Iran from 2003 to 2013.Three information databases were used to systematically select papers using key words including Iranian Magazine Database (MAGIRAN), Iran Medical Library (MEDLIB), and Scientific Information Database (SID). Twenty papers were selected and studied .Having been applied in 9 studies, The Trans Theoretical Model (TTM) was the most widespread model in Iran (PENDER in 3 studies, BASNEF in 2, and the Theory of Planned Behavior in 2 studies). With regards to the educational methods, almost all studies used a combination of methods. The most widely used Integrative educational method was group discussion. Only one integrated study was done. Behavior maintenance was not addressed in 75% of the studies. Almost all studies used self-reporting instruments. The effectiveness of educational methods was assessed in none of the studies. Most of the included studies had several methodological weaknesses, which hinder the validity and applicability of their results. According to the findings, the necessity of need assessment in using models, epidemiology and methodology consultation, addressing maintenance of physical activity, using other theories and models such as social marketing and social-cognitive theory, and other educational methods like empirical and complementary are suggested. PMID:25948454

  12. Chapter 2: Theoretical Models for Understanding Physical Activity Behavior among Children and Adolescents--Social Cognitive Theory and Self-Determination Theory

    ERIC Educational Resources Information Center

    Motl, Robert W.

    2007-01-01

    The study of physical activity behavior in youth generally lacks a sufficient theoretical foundation for examining variables that influence that behavior. This is a major limitation because theory guides the search for determinants of behavior and the subsequent interplay between research findings and application. Theory offers a systematically…

  13. Neutron activation analysis in the life sciences

    NASA Astrophysics Data System (ADS)

    Frontasyeva, M. V.

    2011-03-01

    Development of methods for instrumental neutron activation analysis (INAA) and their applications in the life sciences are reviewed. Emphasis is placed on epithermal activation with reactor neutrons (ENAA), and the advantages of this technique in analysis of environmental objects are shown. The results of applied INAA studies in the field of the life sciences carried out at the world's leading nuclear centers are reported. Experience in employing a radioanalytical complex at the IBR-2 reactor (Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna) for such studies is summarized.

  14. Brain activity and cognition: a connection from thermodynamics and information theory

    PubMed Central

    Collell, Guillem; Fauquet, Jordi

    2015-01-01

    The connection between brain and mind is an important scientific and philosophical question that we are still far from completely understanding. A crucial point to our work is noticing that thermodynamics provides a convenient framework to model brain activity, whereas cognition can be modeled in information-theoretical terms. In fact, several models have been proposed so far from both approaches. A second critical remark is the existence of deep theoretical connections between thermodynamics and information theory. In fact, some well-known authors claim that the laws of thermodynamics are nothing but principles in information theory. Unlike in physics or chemistry, a formalization of the relationship between information and energy is currently lacking in neuroscience. In this paper we propose a framework to connect physical brain and cognitive models by means of the theoretical connections between information theory and thermodynamics. Ultimately, this article aims at providing further insight on the formal relationship between cognition and neural activity. PMID:26136709

  15. Brain activity and cognition: a connection from thermodynamics and information theory.

    PubMed

    Collell, Guillem; Fauquet, Jordi

    2015-01-01

    The connection between brain and mind is an important scientific and philosophical question that we are still far from completely understanding. A crucial point to our work is noticing that thermodynamics provides a convenient framework to model brain activity, whereas cognition can be modeled in information-theoretical terms. In fact, several models have been proposed so far from both approaches. A second critical remark is the existence of deep theoretical connections between thermodynamics and information theory. In fact, some well-known authors claim that the laws of thermodynamics are nothing but principles in information theory. Unlike in physics or chemistry, a formalization of the relationship between information and energy is currently lacking in neuroscience. In this paper we propose a framework to connect physical brain and cognitive models by means of the theoretical connections between information theory and thermodynamics. Ultimately, this article aims at providing further insight on the formal relationship between cognition and neural activity. PMID:26136709

  16. Applying the Theory of Planned Behavior to Physical Activity: The Moderating Role of Mental Toughness.

    PubMed

    Hannan, Thomas E; Moffitt, Robyn L; Neumann, David L; Thomas, Patrick R

    2015-10-01

    This study explored whether mental toughness, the capacity to maintain performance under pressure, moderated the relation between physical activity intentions and subsequent behavior. Participants (N = 117) completed the Mental Toughness Index and a theory of planned behavior questionnaire. Seven days later, physical activity was assessed using the International Physical Activity Questionnaire. Attitudes, subjective norms, and perceived behavioral control explained substantial variance (63.1%) in physical activity intentions. Intentions also significantly predicted physical activity behavior. The simple slopes analyses for the moderation effect revealed a nonsignificant intention-behavior relation at low levels of mental toughness. However, intentions were significantly and positively related to physical activity when mental toughness was moderate or high, suggesting that the development of a mentally tough mindset may reduce the gap between behavior and physical activity intention. Future research is needed to confirm these findings and apply them in the design of mental toughness interventions to facilitate physical activity engagement. PMID:26524097

  17. Second-Order Perturbation Theory for Generalized Active Space Self-Consistent-Field Wave Functions.

    PubMed

    Ma, Dongxia; Li Manni, Giovanni; Olsen, Jeppe; Gagliardi, Laura

    2016-07-12

    A multireference second-order perturbation theory approach based on the generalized active space self-consistent-field (GASSCF) wave function is presented. Compared with the complete active space (CAS) and restricted active space (RAS) wave functions, GAS wave functions are more flexible and can employ larger active spaces and/or different truncations of the configuration interaction expansion. With GASSCF, one can explore chemical systems that are not affordable with either CASSCF or RASSCF. Perturbation theory to second order on top of GAS wave functions (GASPT2) has been implemented to recover the remaining electron correlation. The method has been benchmarked by computing the chromium dimer ground-state potential energy curve. These calculations show that GASPT2 gives results similar to CASPT2 even with a configuration interaction expansion much smaller than the corresponding CAS expansion. PMID:27276688

  18. A Multi-Theory Lens Analysis of Project Real World--A Canadian Consumer Education Curriculum.

    ERIC Educational Resources Information Center

    McGregor, Sue L. T.; ChirChir, Valentine; Couch, Rose; Jobolingo, Dorothy; Manyenga, Grace; Pothier, Michelle

    1998-01-01

    Analysis of a consumer education curriculum identified the extent to which modules reflected the perspectives of systems theory, life cycle model, economic exchange theory, and family member involvement model. Results showed that the curriculum assumes students live in nuclear families, neglects effect of consumer decisions on the environment, and…

  19. Knowledge, Identity, & Professionalism: A Grounded Theory Analysis of How Urban Career Teachers Navigate Their Professional Lives

    ERIC Educational Resources Information Center

    Brodeur, Lori J.

    2013-01-01

    This grounded theory study highlights the words of urban career teachers who participated on a wikispace (wiki). The purpose of the investigation was to offer urban career teachers a space, outside of their daily work, in which to recognize and understand their professionalism. The grounded theory content analysis is carried out by way of a study…

  20. Identifying Barriers in Implementing Outcomes-Based Assessment Program Review: A Grounded Theory Analysis

    ERIC Educational Resources Information Center

    Bresciani, Marilee J.

    2011-01-01

    The purpose of this grounded theory study was to identify the typical barriers encountered by faculty and administrators when implementing outcomes-based assessment program review. An analysis of interviews with faculty and administrators at nine institutions revealed a theory that faculty and administrators' promotion, tenure (if applicable),…

  1. How the Construction & Analysis of Digital Movies Support Theory-Building.

    ERIC Educational Resources Information Center

    Goldman-Segall, Ricki; Beers, Maggie; de Castell, Suzanne; Bryson, Mary; Reilly, Brian

    This paper brings together four short discussions that focus on how the construction and analysis of digital movies support theory-building, and whether that theory-building is equitable. Researches who have used digital media extensively over the last decade address how participants in studies using digital media become collaborators and…

  2. Assessing Coverage of Maslow's Theory in Educational Psychology Textbooks: A Content Analysis

    ERIC Educational Resources Information Center

    Wininger, Steven R.; Norman, Antony D.

    2010-01-01

    Although Maslow's hierarchy of needs theory (HNT) is one of the most prevalent theories in psychology, the authors argued that it is also one of the most misinterpreted or misrepresented, particularly in educational psychology textbooks. Therefore, after carefully reading Maslow's writings on HNT they conducted a content analysis of 18 educational…

  3. Evolution of Online Discussion Forum Richness according to Channel Expansion Theory: A Longitudinal Panel Data Analysis

    ERIC Educational Resources Information Center

    Fernandez, Vicenc; Simo, Pep; Sallan, Jose M.; Enache, Mihaela

    2013-01-01

    The selection and use of communication media has been the center of attention for a great number of researchers in the area of organizational communication. The channel expansion theory combines elements of the main theories in this area; however, these investigations have a static cross-sectional design rather than a longitudinal analysis. With…

  4. Using Telephone Conversations to Develop Awareness of Pragmatic Skills: An Activity-Theory-Driven Approach

    ERIC Educational Resources Information Center

    Xia, Saihua

    2009-01-01

    This paper investigates ESL learners' awareness of pragmatic skills utilizing an activity-theory driven approach to perform an inquiry task into problem-solving service call conversations (PSSCs) between native speakers (NS) and non-native speakers of English (NNSs). Eight high-intermediate ESL learners, from five different language backgrounds,…

  5. An Activity Theory Exegesis on Conflict and Contradictions in Networked Discussions and Feedback Exchanges

    ERIC Educational Resources Information Center

    Hadjistassou, Stella K.

    2012-01-01

    The goal of this study was to investigate the culturally afforded contradictions that ten advanced English as a Second Language (ESL) learner encountered when they posted their paper topics and exchanged feedback strategies online and contextualized some of these strategies to draft their papers. Using Cultural-Historical Activity Theory (CHAT),…

  6. Preparing Students for Education, Work, and Community: Activity Theory in Task-Based Curriculum Design

    ERIC Educational Resources Information Center

    Campbell, Chris; MacPherson, Seonaigh; Sawkins, Tanis

    2014-01-01

    This case study describes how sociocultural and activity theory were applied in the design of a publicly funded, Canadian Language Benchmark (CLB)-based English as a Second Language (ESL) credential program and curriculum for immigrant and international students in postsecondary institutions in British Columbia, Canada. The ESL Pathways Project…

  7. Rules, Roles and Tools: Activity Theory and the Comparative Study of E-Learning

    ERIC Educational Resources Information Center

    Benson, Angela; Lawler, Cormac; Whitworth, Andrew

    2008-01-01

    Activity theory (AT) is a powerful tool for investigating "artefacts in use", ie, the ways technologies interrelate with their local context. AT reveals the interfaces between e-learning at the macro- (strategy, policy, "campus-wide" solutions) and the micro-organisational levels (everyday working practice, iterative change, individual…

  8. Investigating Acceptance toward Mobile Learning to Assist Individual Knowledge Management: Based on Activity Theory Approach

    ERIC Educational Resources Information Center

    Liaw, Shu-Sheng; Hatala, Marek; Huang, Hsiu-Mei

    2010-01-01

    Mobile devices could facilitate human interaction and access to knowledge resources anytime and anywhere. With respect to wide application possibilities of mobile learning, investigating learners' acceptance towards it is an essential issue. Based on activity theory approach, this research explores positive factors for the acceptance of m-learning…

  9. Generalization of the Activated Complex Theory of Reaction Rates. II. Classical Mechanical Treatment

    DOE R&D Accomplishments Database

    Marcus, R. A.

    1964-01-01

    In its usual classical form activated complex theory assumes a particular expression for the kinetic energy of the reacting system -- one associated with a rectilinear motion along the reaction coordinate. The derivation of the rate expression given in the present paper is based on the general kinetic energy expression.

  10. Ethical Issues in Agency Evaluation from the Viewpoint of Activity Theory: A Basis for Interorganizational Learning?

    ERIC Educational Resources Information Center

    Huotari, Risto

    2009-01-01

    This article focuses on ethical issues faced in evaluation practice from the viewpoint of third generation of activity theory, which gives a constructive perspective on how contradictions can be a driving force behind interorganizational learning and development in multiactor networks. The problem field is firstly addressed through an illustration…

  11. Exploring Physical Activity by Ethnicity and Gender in College Students Using Social Cognitive Theory

    ERIC Educational Resources Information Center

    Nehl, Eric J.; Blanchard, Chris M.; Kupperman, Janet; Sparling, Phillip; Rhodes, Ryan; Torabi, Mohammad R.; Courneya, Kerry S.

    2012-01-01

    Intervention;The psychological determinants of physical activity (PA) among college students may vary by ethnicity and gender, but few studies have considered these characteristics. This study tested constructs from Social Cognitive Theory (SCT) by ethnicity and gender to explain differences in PA. A total of 231 Blacks (70% female) and 218 White…

  12. Language-Learning Motivation during Short-Term Study Abroad: An Activity Theory Perspective

    ERIC Educational Resources Information Center

    Allen, Heather Willis

    2010-01-01

    This study investigated the development of language-learning motivation during short-term study abroad (SA) for six intermediate-level students of French. Taking an activity theory perspective, findings demonstrated that one of two orientations motivated participants to study or continue studying French at the college level: linguistic motives or…

  13. The Transformation of Learning: Advances in Cultural-Historical Activity Theory

    ERIC Educational Resources Information Center

    van Oers, Bert, Ed.; Wardekker, Wim, Ed.; Elbers, Ed, Ed.; van der Veer, Rene, Ed.

    2010-01-01

    Learning is a changing phenomenon, depending on the advances in theory and research. This book presents a relatively new approach to learning, based on meaningful human activities in cultural practices and in collaboration with others. It draws extensively from the ideas of Lev Vygotsky and his recent followers. The book presents ideas that…

  14. Self-Identity as a Component of the Theory of Planned Behaviour in Predicting Physical Activity

    ERIC Educational Resources Information Center

    Ries, Francis; Hein, Vello; Pihu, Maret; Armenta, Jose Manuel Sevillano

    2012-01-01

    This study aimed to investigate the role of self-identity, defined as salient and enduring aspects of one's self-perception (Sparks, 2000), in relation to adolescent physical activity (PA) intentions within the Theory of Planned Behaviour (TPB). School students aged 12 to 18 from two cultural groups (Estonia and Spain) completed measures of…

  15. Using Activity Theory and its Principle of Contradictions to Guide Research in Educational Technology

    ERIC Educational Resources Information Center

    Murphy, Elizabeth; Rodriguez-Manzanares, Maria A.

    2008-01-01

    This paper describes how activity theory (AT) and its principle of contradictions may be relied on to guide research in educational technology. The paper begins with a theoretical overview of AT and of its principle of contradictions. It follows with a synthesis of studies that have used AT as a lens to study information and communication…

  16. Ethnicity as a Moderator of the Theory of Planned Behavior and Physical Activity in College Students

    ERIC Educational Resources Information Center

    Blanchard, Chris M.; Kupperman, Janet; Sparling, Phil; Nehl, Eric; Rhodes, Ryan E.; Courneya, Kerry S.; Baker, Frank; Hunt, Tiffany

    2007-01-01

    Most college students do not meet physical activity (PA) guidelines, and ethnic disparities exist. The present study examined the utility of the theory of planned behavior (TPB) in explaining PA intentions and behavior in black and white college students and whether any TPB relationships were moderated by ethnicity. Black (n = 170) and white (n =…

  17. Activity Theory and Technology Mediated Interaction: Cognitive Scaffolding Using Question-Based Consultation on "Facebook"

    ERIC Educational Resources Information Center

    Rambe, Patient

    2012-01-01

    Studies that employed activity theory as a theoretical lens for exploring computer-mediated interaction have not adopted social media as their object of study. However, social media provides lecturers with personalised learning environments for diagnostic and prognostic assessments of student mastery of content and deep learning. The integration…

  18. An Activity Theory Perspective on Student-Reported Contradictions in International Telecollaboration

    ERIC Educational Resources Information Center

    Basharina, Olga K.

    2007-01-01

    This process-oriented study focuses on contradictions that emerged in a WebCT bulletin board collaboration among English learners from Japan, Mexico and Russia, and explains them from the perspective of activity theory (Leont'ev, 1978, 1981; Engestrom, 1987, 1999). The study identified a) two "intra-cultural" contradictions--to post or not to…

  19. Investigating Learner Attitudes toward E-Books as Learning Tools: Based on the Activity Theory Approach

    ERIC Educational Resources Information Center

    Liaw, Shu-Sheng; Huang, Hsiu-Mei

    2016-01-01

    This paper investigates the use of e-books as learning tools in terms of learner satisfaction, usefulness, behavioral intention, and learning effectiveness. Based on the activity theory approach, this research develops a research model to understand learner attitudes toward e-books in two physical sizes: 10? and 7?. Results suggest that screen…

  20. Discourse of the Firetenders: Considering Contingent Faculty through the Lens of Activity Theory

    ERIC Educational Resources Information Center

    Doe, Sue; Barnes, Natalie; Bowen, David; Gilkey, David; Smoak, Ginger Guardiola; Ryan, Sarah; Sarell, Kirk; Thomas, Laura H.; Troup, Lucy J.; Palmquist, Mike

    2011-01-01

    In this article, the authors explore the multiple roles that contingent faculty play in an evolving system of higher education. They consider the professional work of faculty in contingent positions at Colorado State University through the lens of activity theory, analyzing workplace discourse logs in an effort to understand the roles of…

  1. Experiences of Learning and Teaching Mathematics: Using Activity Theory to Understand Tensions in Practice

    ERIC Educational Resources Information Center

    Page, Shaileigh; Clark, Julie

    2010-01-01

    This paper originates from a larger qualitative study exploring how teachers incorporate the affective domain into the primary mathematics classroom. This paper analyses teacher's experiences of mathematics and explores, using activity theory, how these experiences impact their teaching. An important factor to emerge from the data was teacher's…

  2. Exploring Students' Perceptions about Learning in School: An Activity Theory Based Study

    ERIC Educational Resources Information Center

    Portnov-Neeman, Yelena; Barak, Moshe

    2013-01-01

    In the current study, we used Activity Theory as the conceptual framework for exploring students' perceptions about how learning in school is affected by the following five elements: Object, Tools, Rules, Community and Division of Labor. Data were collected by administrating a semi-structured questionnaire among 70 junior high school students and…

  3. Activity Theory as a Conceptual Framework for Understanding Teacher Approaches to Information and Communication Technologies

    ERIC Educational Resources Information Center

    Karasavvidis, Ilias

    2009-01-01

    While the issue of teachers' perspectives on the barriers to technology use has received considerable attention, teacher concerns have not been studied in a systematic and holistic way. The present paper examines teacher concerns regarding a proposed technology-based innovation using Activity Theory as a theoretical framework. Fifty-one teachers…

  4. Understanding Wikibook-Based Tensions in Higher Education: An Activity Theory Approach

    ERIC Educational Resources Information Center

    Karasavvidis, Ilias

    2010-01-01

    Research has indicated that the integration of wikis in higher education is very challenging. The present article focuses on the tensions emerging from the integration of a wikibook as a required assignment in an undergraduate course. Drawing on data from a case study, the article uses Activity Theory as a theoretical framework in order to…

  5. Understanding and Dismantling Barriers for Partnerships for Inclusive Education: A Cultural Historical Activity Theory Perspective

    ERIC Educational Resources Information Center

    Waitoller, Federico R.; Kozleski, Elizabeth B.

    2013-01-01

    Increasingly, universities and school districts share responsibility for teacher and student learning. Sharing responsibility demands that both institutions work to develop closer relationships through ongoing engagement, dialogue and negotiation. Drawing from Cultural Historical Activity Theory (CHAT), we examined one school/university…

  6. Transforming Pedagogy through Interactive Whiteboards: Using Activity Theory to Understand Tensions in Practice

    ERIC Educational Resources Information Center

    Sweeney, Trudy

    2010-01-01

    There has been considerable investment in the use of interactive whiteboard technology in Australia, particularly in primary schools. School leaders and teachers are seeking advice on effective ways to support teachers' pedagogical development to achieve the potential benefits of these devices. Using activity theory as a framework for lesson…

  7. Methodologies in Cultural-Historical Activity Theory: The Example of School-Based Development

    ERIC Educational Resources Information Center

    Postholm, May Britt

    2015-01-01

    Background and purpose: Relatively little research has been conducted on methodology within Cultural-Historical Activity Theory (CHAT). CHAT is mainly used as a framework for developmental processes. The purpose of this article is to discuss both focuses for research and research questions within CHAT and to outline methodologies that can be used…

  8. Using Social Cognitive Theory to Predict Physical Activity and Fitness in Underserved Middle School Children

    ERIC Educational Resources Information Center

    Martin, Jeffrey J.; McCaughtry, Nate; Flory, Sara; Murphy, Anne; Wisdom, Kimberlydawn

    2011-01-01

    Few researchers have used social cognitive theory and environment-based constructs to predict physical activity (PA) and fitness in underserved middle-school children. Hence, we evaluated social cognitive variables and perceptions of the school environment to predict PA and fitness in middle school children (N = 506, ages 10-14 years). Using…

  9. Using Activity Theory to Understand Intergenerational Play: The Case of Family Quest

    ERIC Educational Resources Information Center

    Siyahhan, Sinem; Barab, Sasha A.; Downton, Michael P.

    2010-01-01

    We implemented a five-week family program called "Family Quest" where parents and children ages 9 to 13 played Quest Atlantis, a multiuser 3D educational computer game, at a local after-school club for 90-minute sessions. We used activity theory as a conceptual and an analytical framework to study the nature of intergenerational play, the…

  10. Science and Social Practice: Action Research and Activity Theory as Socio-Critical Approaches

    ERIC Educational Resources Information Center

    Langemeyer, Ines

    2011-01-01

    Action research and activity theory are considered by a number of followers as socio-critical approaches, whereas others do not relate them to social-criticism and use them merely as methods to improve practice. This article searches for general insights in Kurt Lewin's and Lev S. Vygotsky's work into how one proceeds and acts critically. In their…

  11. Pavlov's Position on Old Age within the Framework of the Theory of Higher Nervous Activity.

    ERIC Educational Resources Information Center

    Windholz, George

    1995-01-01

    In later life, I. P. Pavlov incorporated his findings on aging into his theory of higher nervous activity. Some of the major findings showed that salivary conditioning and stimulus differentiation were difficult to establish in old dogs, but that conditioned reflexes established earlier in life persisted into old age. Pavlov hypothesized that…

  12. Activity Theory, Complexity and Sports Coaching: An Epistemology for a Discipline

    ERIC Educational Resources Information Center

    Jones, Robyn L.; Edwards, Christian; Filho, I. A. Tuim Viotto

    2016-01-01

    The aim of this article is twofold. First, it is to advance the case for activity theory (AT) as a credible and alternative lens to view and research sports coaching. Second, it is to position this assertion within the wider debate about the epistemology of coaching. Following a framing introduction, a more comprehensive review of the development…

  13. Generalization of the Activated Complex Theory of Reaction Rates. I. Quantum Mechanical Treatment

    DOE R&D Accomplishments Database

    Marcus, R. A.

    1964-01-01

    In its usual form activated complex theory assumes a quasi-equilibrium between reactants and activated complex, a separable reaction coordinate, a Cartesian reaction coordinate, and an absence of interaction of rotation with internal motion in the complex. In the present paper a rate expression is derived without introducing the Cartesian assumption. The expression bears a formal resemblance to the usual one and reduces to it when the added assumptions of the latter are introduced.

  14. Negative reactions to depressive behaviors: a communication theories analysis.

    PubMed

    Segrin, C; Abramson, L Y

    1994-11-01

    Interpersonal aspects of depression have received considerable research attention in the past 2 decades. This work often has been guided by J. C. Coyne's (1976b) interactional model of depression or P. M. Lewinsohn's (1974) social skill deficit theory of depression. A review of this research indicates that depressed people reliably experience rejection from those in their social environment and that depression generally is associated with impairments in social behavior. However, this research does not explain exactly what depressed people do to elicit rejection, or exactly why others react negatively to them. Research derived from communication theories on responsiveness, politeness, and expectations for nonverbal involvement illuminates the interpersonal cycle in depression. The role of these impairments in the cause, symptoms, course, subtypes, and therapy of depression is discussed. PMID:7822566

  15. Theoretical analysis for moiré deflectometry from diffraction theory.

    PubMed

    Song, Yang; Chen, Yun Yun; He, Anzhi; Zhao, Zhimin

    2009-04-01

    Theories of moiré deflectometry are presented based on scalar diffraction theory. It is shown that the moiré effect is not a pure geometric phenomenon but actually the result of multishearing interference. By performing zeroth-order or first-order filtering, the field in the plane of observation is seen to be the result of double- or triple-shearing interference, respectively. With first-order filtering, the intensity distribution is proved to be a strict cosinusoidal intensity distribution, and the diffraction effect, which depends on the distance between two gratings, affects just the phase shift of the moiré fringes. Compared with previous research, a more precise relation between the unwrapped phase and the deflection angles is obtained. The results will be very useful for image processing of moiré patterns with Fourier transform profilometry and phase-shift methods. PMID:19340262

  16. Simultaneous analysis of biologically active aminoalkanephosphonic acids.

    PubMed

    Kudzin, Zbigniew H; Gralak, Dorota K; Andrijewski, Grzegorz; Drabowicz, Józef; Luczak, Jerzy

    2003-05-23

    A new approach for simultaneous analysis of biologically active aminoalkanephosphonic acids, namely glyphosate, phosphonoglycine, phosphonosarcosine, phosphonoalanine, phosphono-beta-alanine, phosphonohomoalanine, phosphono-gamma-homoalanine and glufosinate, is presented. This includes a preliminary 31p NMR analysis of these amino acids, their further derivatization to volatile phosphonates (phosphinates) by means of trifluoroacetic acid-trifluoroacetic anhydride-trimethyl orthoacetate reagent and subsequent analysis of derivatization products using MS and/or GC-MS (chemical ionization and/or electron impact ionization). PMID:12862383

  17. Path Analysis: A Link between Family Theory and Reseach.

    ERIC Educational Resources Information Center

    Rank, Mark R.; Sabatelli, Ronald M.

    This paper discusses path analysis and the applicability of this methodology to the field of family studies. The statistical assumptions made in path analysis are presented along with a description of the two types of models within path analysis, i.e., recursive and non-recursive. Methods of calculating in the path model and the advantages of…

  18. Analysis of vibrational, structural, and electronic properties of rivastigmine by density functional theory

    NASA Astrophysics Data System (ADS)

    Prasad, O.; Sinha, L.; Misra, N.; Narayan, V.; Kumar, N.; Kumar, A.

    2010-09-01

    The present work deals with the structural, electronic, and vibrational analysis of rivastigmine. Rivastigmine, an antidementia medicament, is credited with significant therapeutic effects on the cognitive, functional, and behavioural problems that are commonly associated with Alzheimer’s dementia. For rivastigmine, a number of minimum energy conformations are possible. The geometry of twelve possible conformers has been analyzed and the most stable conformer was further optimized at a higher basis set. The electronic properties and vibrational frequencies were then calculated using a density functional theory at the B3LYP level with the 6-311+G(d, p) basis set. The different molecular surfaces have also been drawn to understand the activity of the molecule. A narrower frontier orbital energy gap in rivastigmine makes it softer and more reactive than water and dimethylfuran. The calculated value of the dipole moment is 2.58 debye.

  19. An analysis of changing trends in philosophies of science on nursing theory development and testing.

    PubMed

    Silva, M C; Rothbart, D

    1984-01-01

    The effects of changing trends in philosophies of science on nursing theory development and testing are analyzed. Two philosophies of science--logical empiricism and historicism--are compared for four variables: (1) components of science, (2) conception of science, (3) assessment of scientific progress, and (4) goal of philosophy of science. These factors serve as the basis for assessing trends in the development and testing of nursing theory from 1964 to the present. The analysis shows a beginning philosophic shift within nursing theory from logical empiricism to historicism and addresses implications and recommendations for future nursing theory development and testing. PMID:6422835

  20. The Interaction between Multimedia Data Analysis and Theory Development in Design Research

    ERIC Educational Resources Information Center

    van Nes, Fenna; Doorman, Michiel

    2010-01-01

    Mathematics education researchers conducting instruction experiments using a design research methodology are challenged with the analysis of often complex and large amounts of qualitative data. In this paper, we present two case studies that show how multimedia analysis software can greatly support video data analysis and theory development in…

  1. Theory on the dynamic memory in the transcription-factor-mediated transcription activation

    NASA Astrophysics Data System (ADS)

    Murugan, R.

    2011-04-01

    We develop a theory to explain the origin of the static and dynamical memory effects in transcription-factor-mediated transcription activation. Our results suggest that the following inequality conditions should be satisfied to observe such memory effects: (a) τL≫max(τR,τE), (b) τLT≫τT, and (c) τI⩾(τEL+τTR) where τL is the average time required for the looping-mediated spatial interactions of enhancer—transcription-factor complex with the corresponding promoter—RNA-polymerase or eukaryotic RNA polymerase type II (PolII in eukaryotes) complex that is located L base pairs away from the cis-acting element, (τR,τE) are respectively the search times required for the site-specific binding of the RNA polymerase and the transcription factor with the respective promoter and the cis-regulatory module, τLT is the time associated with the relaxation of the looped-out segment of DNA that connects the cis-acting site and promoter, τT is the time required to generate a complete transcript, τI is the transcription initiation time, τEL is the elongation time, and τTR is the termination time. We have theoretically derived the expressions for the various searching, looping, and loop-relaxation time components. Using the experimentally determined values of various time components we further show that the dynamical memory effects cannot be experimentally observed whenever the segment of DNA that connects the cis-regulatory element with the promoter is not loaded with bulky histone bodies. Our analysis suggests that the presence of histone-mediated compaction of the connecting segment of DNA can result in higher values of looping and loop-relaxation times, which is the origin of the static memory in the transcription activation that is mediated by the memory gene loops in eukaryotes.

  2. Cross talk analysis in multicore optical fibers by supermode theory.

    PubMed

    Szostkiewicz, Lukasz; Napierala, Marek; Ziolowicz, Anna; Pytel, Anna; Tenderenda, Tadeusz; Nasilowski, Tomasz

    2016-08-15

    We discuss the theoretical aspects of core-to-core power transfer in multicore fibers relying on supermode theory. Based on a dual core fiber model, we investigate the consequences of this approach, such as the influence of initial excitation conditions on cross talk. Supermode interpretation of power coupling proves to be intuitive and thus may lead to new concepts of multicore fiber-based devices. As a conclusion, we propose a definition of a uniform cross talk parameter that describes multicore fiber design. PMID:27519082

  3. Analysis of the theory of high energy ion transport

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1977-01-01

    Procedures for the approximation of the transport of high-energy ions are discussed on the basis of available data on ion nuclear reactions. A straightahead approximation appears appropriate for space applications. The assumption that the secondary-ion-fragment velocity is equal to that of the fragmenting nucleus is inferior to straightahead theory but is of sufficient accuracy if the primary ions display a broad energy spectrum. An iterative scheme for the solution of the inhomogenous integral transport equations holds promise for practical calculation. A model calculation shows that multiple charged ion fragments penetrate to greater depths in comparison with the free path of a primary heavy ion.

  4. Exercise, physical activity, and self-determination theory: A systematic review

    PubMed Central

    2012-01-01

    Background Motivation is a critical factor in supporting sustained exercise, which in turn is associated with important health outcomes. Accordingly, research on exercise motivation from the perspective of self-determination theory (SDT) has grown considerably in recent years. Previous reviews have been mostly narrative and theoretical. Aiming at a more comprehensive review of empirical data, this article examines the empirical literature on the relations between key SDT-based constructs and exercise and physical activity behavioral outcomes. Methods This systematic review includes 66 empirical studies published up to June 2011, including experimental, cross-sectional, and prospective studies that have measured exercise causality orientations, autonomy/need support and need satisfaction, exercise motives (or goal contents), and exercise self-regulations and motivation. We also studied SDT-based interventions aimed at increasing exercise behavior. In all studies, actual or self-reported exercise/physical activity, including attendance, was analyzed as the dependent variable. Findings are summarized based on quantitative analysis of the evidence. Results The results show consistent support for a positive relation between more autonomous forms of motivation and exercise, with a trend towards identified regulation predicting initial/short-term adoption more strongly than intrinsic motivation, and intrinsic motivation being more predictive of long-term exercise adherence. The literature is also consistent in that competence satisfaction and more intrinsic motives positively predict exercise participation across a range of samples and settings. Mixed evidence was found concerning the role of other types of motives (e.g., health/fitness and body-related), and also the specific nature and consequences of introjected regulation. The majority of studies have employed descriptive (i.e., non-experimental) designs but similar results are found across cross

  5. Content Analysis of Turkish Studies about the Multiple Intelligences Theory

    ERIC Educational Resources Information Center

    Saban, Ahmet

    2009-01-01

    Recently, there has been a significant increase in the number of multiple intelligences (MI) studies in Turkey. Consequently, a systematic analysis of these studies is crucial in order to be able to see the present situation and future trends in the field of education. By this way, it is also hoped that the current analysis will offer an avenue…

  6. Activity Analysis and Cost Analysis in Medical Schools.

    ERIC Educational Resources Information Center

    Koehler, John E.; Slighton, Robert L.

    There is no unique answer to the question of what an ongoing program costs in medical schools. The estimates of program costs generated by classical methods of cost accounting are unsatisfactory because such accounting cannot deal with the joint production or joint cost problem. Activity analysis models aim at calculating the impact of alternative…

  7. An intergrative factor analysis of leadership measures and theories.

    PubMed

    Sweney, A B; Fiechtner, L A; Samores, R J

    1975-05-01

    Since the instruments for measuring most of the current leadership models have never been reconciled, it is important that the relationships between them be clearly understood before assumptions of similarity are made. A sample of 103 male working students were given a battery of tests measuring leadership orientations. The tests included role preference and role pressure measures from Sweney's Response to Power Model, the California F Scale, Fiedler's Least Preferred Co-Worker Scale and Assumed Similarity Between Opposites Scale, Costley and Downey's six scales to measure McGregor's "Theory X" and "Theory Y" constructs, modified scales for the Blake and Mouton Managerial Grid, and relevant scales from the 16 PF. The results were intercorrelated and yielded 11 varimax factors based upon a Guttman criterion, as follows: Authoritarian Role Preferance, Authoritarian Role Pressure, Equalitarian Role Preferance, Equalitarian Role Pressure, Balanced Manager, People Oriented Manager, Assumed Similarity Between Opposites, Contemptuous Indulgence, Supportive Values, People Tolerance, and Organizational Tolerance. The instruments measuring authoritarianism loaded the first factor in the right direction, but most of them had their primary loadings elsewhere, suggesting greater conceptual complexity to this area than previously recognized. PMID:1151904

  8. Phase Behavior of Active Swimmers in Depletants: Molecular Dynamics and Integral Equation Theory

    NASA Astrophysics Data System (ADS)

    Das, Subir K.; Egorov, Sergei A.; Trefz, Benjamin; Virnau, Peter; Binder, Kurt

    2014-05-01

    We study the structure and phase behavior of a binary mixture where one of the components is self-propelling in nature. The interparticle interactions in the system are taken from the Asakura-Oosawa model for colloid-polymer mixtures for which the phase diagram is known. In the current model version, the colloid particles are made active using the Vicsek model for self-propelling particles. The resultant active system is studied by molecular dynamics methods and integral equation theory. Both methods produce results consistent with each other and demonstrate that the Vicsek model-based activity facilitates phase separation, thus, broadening the coexistence region.

  9. Phase behavior of active swimmers in depletants: molecular dynamics and integral equation theory.

    PubMed

    Das, Subir K; Egorov, Sergei A; Trefz, Benjamin; Virnau, Peter; Binder, Kurt

    2014-05-16

    We study the structure and phase behavior of a binary mixture where one of the components is self-propelling in nature. The interparticle interactions in the system are taken from the Asakura-Oosawa model for colloid-polymer mixtures for which the phase diagram is known. In the current model version, the colloid particles are made active using the Vicsek model for self-propelling particles. The resultant active system is studied by molecular dynamics methods and integral equation theory. Both methods produce results consistent with each other and demonstrate that the Vicsek model-based activity facilitates phase separation, thus, broadening the coexistence region. PMID:24877969

  10. The Significance of Turning Passive Into Active in Control Mastery Theory

    PubMed Central

    FOREMAN, STEVEN A.

    1996-01-01

    Turning passive into active was first described by Freud but was later given expanded importance by Weiss. This new conceptualization of turning passive into active as an interpersonal communication and test has made a major contribution to the clinical treatment of difficult patients. This article reviews "control mastery" theory and puts its notion of passive-into-active testing into perspective with regard to Freud’s original conception as well as other conceptions, such as identification with the aggressor and projective identification. Formulation and the treatment of patients are illustrated with clinical examples. PMID:22700271

  11. Neutron activation analysis of Etruscan pottery

    SciTech Connect

    Whitehead, J.; Silverman, A.; Ouellet, C.G.; Clark, D.D.; Hossain, T.Z

    1992-07-01

    Neutron activation analysis (NAA) has been widely used in archaeology for compositional analysis of pottery samples taken from sites of archaeological importance. Elemental profiles can determine the place of manufacture. At Cornell, samples from an Etruscan site near Siena, Italy, are being studied. The goal of this study is to compile a trace element concentration profile for a large number of samples. These profiles will be matched with an existing data bank in an attempt to understand the place of origin for these samples. The 500 kW TRIGA reactor at the Ward Laboratory is used to collect NAA data for these samples. Experiments were done to set a procedure for the neutron activation analysis with respect to sample preparation, selection of irradiation container, definition of activation and counting parameters and data reduction. Currently, we are able to analyze some 27 elements in samples of mass 500 mg with a single irradiation of 4 hours and two sequences of counting. Our sensitivity for many of the trace elements is better than 1 ppm by weight under the conditions chosen. In this talk, details of our procedure, including quality assurance as measured by NIST standard reference materials, will be discussed. In addition, preliminary results from data treatment using cluster analysis will be presented. (author)

  12. Theory, Image Simulation, and Data Analysis of Chemical Release Experiments

    NASA Technical Reports Server (NTRS)

    Wescott, Eugene M.

    1994-01-01

    The final phase of Grant NAG6-1 involved analysis of physics of chemical releases in the upper atmosphere and analysis of data obtained on previous NASA sponsored chemical release rocket experiments. Several lines of investigation of past chemical release experiments and computer simulations have been proceeding in parallel. This report summarizes the work performed and the resulting publications. The following topics are addressed: analysis of the 1987 Greenland rocket experiments; calculation of emission rates for barium, strontium, and calcium; the CRIT 1 and 2 experiments (Collisional Ionization Cross Section experiments); image calibration using background stars; rapid ray motions in ionospheric plasma clouds; and the NOONCUSP rocket experiments.

  13. Active matter beyond mean-field: Ring-kinetic theory for self-propelled particles

    NASA Astrophysics Data System (ADS)

    Chou, Yen-Liang; Ihle, Thomas

    2015-02-01

    Recently, Hanke et al. [Phys. Rev. E 88, 052309 (2013), 10.1103/PhysRevE.88.052309] showed that mean-field kinetic theory fails to describe collective motion in soft active colloids and that correlations must not be neglected. Correlation effects are also expected to be essential in systems of biofilaments driven by molecular motors and in swarms of midges. To obtain correlations in an active matter system from first principles, we derive a ring-kinetic theory for Vicsek-style models of self-propelled agents from the exact N -particle evolution equation in phase space. The theory goes beyond mean-field and does not rely on Boltzmann's approximation of molecular chaos. It can handle precollisional correlations and cluster formation, which are both important to understand the phase transition to collective motion. We propose a diagrammatic technique to perform a small-density expansion of the collision operator and derive the first two equations of the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy. An algorithm is presented that numerically solves the evolution equation for the two-particle correlations on a lattice. Agent-based simulations are performed and informative quantities such as orientational and density correlation functions are compared with those obtained by ring-kinetic theory. Excellent quantitative agreement between simulations and theory is found at not-too-small noises and mean free paths. This shows that there are parameter ranges in Vicsek-like models where the correlated closure of the BBGKY hierarchy gives correct and nontrivial results. We calculate the dependence of the orientational correlations on distance in the disordered phase and find that it seems to be consistent with a power law with an exponent around -1.8 , followed by an exponential decay. General limitations of the kinetic theory and its numerical solution are discussed.

  14. STICAP: A linear circuit analysis program with stiff systems capability. Volume 1: Theory manual. [network analysis

    NASA Technical Reports Server (NTRS)

    Cooke, C. H.

    1975-01-01

    STICAP (Stiff Circuit Analysis Program) is a FORTRAN 4 computer program written for the CDC-6400-6600 computer series and SCOPE 3.0 operating system. It provides the circuit analyst a tool for automatically computing the transient responses and frequency responses of large linear time invariant networks, both stiff and nonstiff (algorithms and numerical integration techniques are described). The circuit description and user's program input language is engineer-oriented, making simple the task of using the program. Engineering theories underlying STICAP are examined. A user's manual is included which explains user interaction with the program and gives results of typical circuit design applications. Also, the program structure from a systems programmer's viewpoint is depicted and flow charts and other software documentation are given.

  15. An information theory analysis of visual complexity and dissimilarity.

    PubMed

    Donderi, Don C

    2006-01-01

    The subjective complexity of a computer-generated bitmap image can be measured by magnitude estimation scaling, and its objective complexity can be measured by its compressed file size. There is a high correlation between these measures of subjective and objective complexity over a large set of marine electronic chart and radar images. The subjective dissimilarity of a pair of bitmap images can be predicted from subjective and objective measures of the complexity of each image, and from the subjective and objective complexity of the image produced by overlaying the two simple images. In addition, the subjective complexity of the image produced by overlaying two simple images can be predicted from the subjective complexity of the simple images and the subjective dissimilarity of the image pair. The results of the experiments that generated these complexity and dissimilarity judgments are consistent with a theory, outlined here, that treats objective and subjective measures of image complexity and dissimilarity as vectors in Euclidean space. PMID:16836047

  16. Analysis of drivers' characteristics in car-following theory

    NASA Astrophysics Data System (ADS)

    Zhang, Geng; Sun, Di-Hua; Liu, Hui; Zhao, Min

    2014-09-01

    In recent years, the influence of drivers' behaviors on traffic flow has attracted considerable attention according to Transportation Cyber Physical Systems. In this paper, an extended car-following model is presented by considering drivers' timid or aggressive characteristics. The impact of drivers' timid or aggressive characteristics on the stability of traffic flow has been analyzed through linear stability theory and nonlinear reductive perturbation method. Numerical simulation shows that the propagating behavior of traffic density waves near the critical point can be described by the kink-antikink soliton of the mKdV equation. The good agreement between the numerical simulation and the analytical results shows that drivers' characteristics play an important role in traffic jamming transition.

  17. Correspondence Analysis-Theory and Application in Management Accounting Research

    NASA Astrophysics Data System (ADS)

    Duller, Christine

    2010-09-01

    Correspondence analysis is an explanatory data analytic technique and is used to identify systematic relations between categorical variables. It is related to principal component analysis and the results provide information on the structure of categorical variables similar to the results given by a principal component analysis in case of metric variables. Classical correspondence analysis is designed two-dimensional, whereas multiple correspondence analysis is an extension to more than two variables. After an introductory overview of the idea and the implementation in standard software packages (PASW, SAS, R) an example in recent research is presented, which deals with strategic management accounting in family and non-family enterprises in Austria, where 70% to 80% of all enterprises can be classified as family firms. Although there is a growing body of literature focusing on various management issues in family firms, so far the state of the art of strategic management accounting in family firms is an empirically under-researched subject. In relevant literature only the (empirically untested) hypothesis can be found, that family firms tend to have less formalized management accounting systems than non-family enterprises. Creating a correspondence analysis will help to identify the underlying structure, which is responsible for differences in strategic management accounting.

  18. Understanding Physical Activity Intention in Canadian School Children and Youth: An Application of the Theory of Planned Behavior.

    ERIC Educational Resources Information Center

    Mummery, W. Kerry; Spence, John C.; Hudee, John C.

    2000-01-01

    Investigated how well the theory of planned behavior could predict students' physical activity intention. Surveys indicated that direct measures of the theory of planned behavior explained 47 percent of variability in the measure of physical activity intention. Differences surfaced in the relative contributions of three predictors (attitude,…

  19. THEOR"ACTIVE" Learning: How "Theory" and "Practice" Meet. Perception of Students at the University of Tampere, Finland

    ERIC Educational Resources Information Center

    Rajbhandari, Mani Man Singh; Basaran, Kenan; Hujala, Eeva; Kinos, Jarmo

    2011-01-01

    THEOR"ACTIVE" learning is a multi dimensional attachment of theories and practices. The study explores to identify the implementation of theories into practices and how it is being perceived by the students. The research on THEOR"ACTIVE" was conducted with the master degree student coming from different countries at the…

  20. Modal analysis of turborotors using planar modes - Theory

    NASA Technical Reports Server (NTRS)

    Gunter, E. J.; Choy, K. C.; Allaire, P. E.

    1978-01-01

    The generalized dynamic equations of motion have been obtained by the direct stiffness method for multimass flexible rotor bearing systems including the effects of gyroscopic moments, disk skew, and rotor acceleration. A set of undamped critical speed mode shapes calculated from the average horizontal and vertical bearing stiffness is used to transform the equations of motion into a set of coupled modal equations of motion. The modal equations are coupled by the generalized bearing coefficients and the gyroscopic moments. An analysis using only undamped critical speeds or decoupled modal analysis assuming proportional damping may lead to erroneous results. This paper presents a rapid method of calculating rotor resonance speeds with their corresponding amplification factors, stability and unbalance response of turborotors. Examples of the application of this modal approach are presented and results are compared to those of other methods such as matrix transfer analysis.

  1. Stress-deformation theories for the analysis of steel beams reinforced with GFRP plates

    NASA Astrophysics Data System (ADS)

    Phe, Pham Van

    A theory is developed for the analysis of composite systems consisting of steel wide flange sections reinforced with GFRP plates connected to one of the flanges through a layer of adhesive. The theory is based on an extension of the Gjelsvik theory and thus incorporates local and global warping effects but omits shear deformation effects. The theory captures the longitudinal transverse response through a system of three coupled differential equations of equilibrium and the lateral-torsional response through another system of three coupled differential equations. Closed form solutions are developed and a super-convergent finite element is formulated based under the new theory. A comparison to 3D FEA results based on established solid elements in Abaqus demonstrates the validity of the theory when predicting the longitudinal-transverse response, but showcases its shortcomings in predicting the torsional response of the composite system. The comparison sheds valuable insight on means of improving the theory. A more advanced theory is subsequently developed based on enriched kinematics which incorporates shear deformation effects. The shear deformable theory captures the longitudinal-transverse response through a system of four coupled differential equations of equilibrium and the lateral-torsional response through another system of six coupled differential equations. A finite difference approximation is developed for the new theory and a new finite element formulation is subsequently to solve the new system of equations. A comparison to 3D FEA illustrates the validity of the shear deformable theory in predicting the longitudinal-transverse response as well as the lateral-torsional response. Both theories are shown to be computationally efficient and reduce the modelling and running time from several hours per run to a few minutes or seconds while capturing the essential features of the response of the composite system.

  2. Ockham's razor and Bayesian analysis. [statistical theory for systems evaluation

    NASA Technical Reports Server (NTRS)

    Jefferys, William H.; Berger, James O.

    1992-01-01

    'Ockham's razor', the ad hoc principle enjoining the greatest possible simplicity in theoretical explanations, is presently shown to be justifiable as a consequence of Bayesian inference; Bayesian analysis can, moreover, clarify the nature of the 'simplest' hypothesis consistent with the given data. By choosing the prior probabilities of hypotheses, it becomes possible to quantify the scientific judgment that simpler hypotheses are more likely to be correct. Bayesian analysis also shows that a hypothesis with fewer adjustable parameters intrinsically possesses an enhanced posterior probability, due to the clarity of its predictions.

  3. Analysis of Students' Arguments on Evolutionary Theory

    ERIC Educational Resources Information Center

    Basel, Nicolai; Harms, Ute; Prechtl, Helmut

    2013-01-01

    A qualitative exploratory study was conducted to reveal students' argumentation skills in the context of the topic of evolution. Transcripts from problem-centred interviews on secondary students' beliefs about evolutionary processes of adaptation were analysed using a content analysis approach. For this purpose two categorical systems…

  4. Self in Career Theory and Counselling: A Discourse Analysis Perspective

    ERIC Educational Resources Information Center

    Stead, Graham B.; Bakker, Terri M.

    2010-01-01

    A rapidly changing postmodern working world demands revised conceptualisations of the self. Recent scholarship in discourse analysis invites an investigation into how selves are constructed and fabricated within a complex matrix of social discourses, and how this may impact on the field of career counselling and development. This paper examines…

  5. Regression Commonality Analysis: A Technique for Quantitative Theory Building

    ERIC Educational Resources Information Center

    Nimon, Kim; Reio, Thomas G., Jr.

    2011-01-01

    When it comes to multiple linear regression analysis (MLR), it is common for social and behavioral science researchers to rely predominately on beta weights when evaluating how predictors contribute to a regression model. Presenting an underutilized statistical technique, this article describes how organizational researchers can use commonality…

  6. A Unified Framework for Monetary Theory and Policy Analysis.

    ERIC Educational Resources Information Center

    Lagos, Ricardo; Wright, Randall

    2005-01-01

    Search-theoretic models of monetary exchange are based on explicit descriptions of the frictions that make money essential. However, tractable versions of these models typically make strong assumptions that render them ill suited for monetary policy analysis. We propose a new framework, based on explicit micro foundations, within which macro…

  7. Microstructure analysis of monodisperse ferrofluid monolayers: theory and simulation.

    PubMed

    Kantorovich, Sofia; Cerdà, Juan J; Holm, Christian

    2008-04-14

    We try to elucidate the microstructure formation in a monodisperse ferrofluid monolayer. The system under study consists of soft sphere magnetic dipolar particles confined to a thin fluid layer. The positions of the particles are constrained to a 2D geometry, whereas the particle magnetic dipole moments are not fixed to the body systems, and are free to rotate in 3 dimensions, hence forming in what we call a quasi-2D geometry. Using a combination of analytical density functional theory and molecular dynamics (MD) simulations, we find that for the studied range of parameters the majority of aggregates might be divided into two types: chains and rings. Their sizes and area fractions are strongly influenced by the geometrical constraints. We show that for quasi-2D systems the excluded area effects play one of the most important parts in the microstructure formation. The simulation technique and the theoretical model put forward in the present paper agree qualitatively with the results of recent in situ observations of the microstructures observed in ferrofluid monolayers [M. Klokkenberg, R. P. A. Dullens, W. K. Regel, B. H. Erné, A. P. Philipse, Phys. Rev. Lett., 2006, 96, 037203]. PMID:18368181

  8. Commodity predictability analysis with a permutation information theory approach

    NASA Astrophysics Data System (ADS)

    Zunino, Luciano; Tabak, Benjamin M.; Serinaldi, Francesco; Zanin, Massimiliano; Pérez, Darío G.; Rosso, Osvaldo A.

    2011-03-01

    It is widely known that commodity markets are not totally efficient. Long-range dependence is present, and thus the celebrated Brownian motion of prices can be considered only as a first approximation. In this work we analyzed the predictability in commodity markets by using a novel approach derived from Information Theory. The complexity-entropy causality plane has been recently shown to be a useful statistical tool to distinguish the stage of stock market development because differences between emergent and developed stock markets can be easily discriminated and visualized with this representation space [L. Zunino, M. Zanin, B.M. Tabak, D.G. Pérez, O.A. Rosso, Complexity-entropy causality plane: a useful approach to quantify the stock market inefficiency, Physica A 389 (2010) 1891-1901]. By estimating the permutation entropy and permutation statistical complexity of twenty basic commodity future markets over a period of around 20 years (1991.01.02-2009.09.01), we can define an associated ranking of efficiency. This ranking is quantifying the presence of patterns and hidden structures in these prime markets. Moreover, the temporal evolution of the commodities in the complexity-entropy causality plane allows us to identify periods of time where the underlying dynamics is more or less predictable.

  9. Efficiency and credit ratings: a permutation-information-theory analysis

    NASA Astrophysics Data System (ADS)

    Fernandez Bariviera, Aurelio; Zunino, Luciano; Belén Guercio, M.; Martinez, Lisana B.; Rosso, Osvaldo A.

    2013-08-01

    The role of credit rating agencies has been under severe scrutiny after the subprime crisis. In this paper we explore the relationship between credit ratings and informational efficiency of a sample of thirty nine corporate bonds of US oil and energy companies from April 2008 to November 2012. For this purpose we use a powerful statistical tool, relatively new in the financial literature: the complexity-entropy causality plane. This representation space allows us to graphically classify the different bonds according to their degree of informational efficiency. We find that this classification agrees with the credit ratings assigned by Moody’s. In particular, we detect the formation of two clusters, which correspond to the global categories of investment and speculative grades. Regarding the latter cluster, two subgroups reflect distinct levels of efficiency. Additionally, we also find an intriguing absence of correlation between informational efficiency and firm characteristics. This allows us to conclude that the proposed permutation-information-theory approach provides an alternative practical way to justify bond classification.

  10. Random matrix theory analysis of cross correlations in financial markets

    NASA Astrophysics Data System (ADS)

    Utsugi, Akihiko; Ino, Kazusumi; Oshikawa, Masaki

    2004-08-01

    We confirm universal behaviors such as eigenvalue distribution and spacings predicted by random matrix theory (RMT) for the cross correlation matrix of the daily stock prices of Tokyo Stock Exchange from 1993 to 2001, which have been reported for New York Stock Exchange in previous studies. It is shown that the random part of the eigenvalue distribution of the cross correlation matrix is stable even when deterministic correlations are present. Some deviations in the small eigenvalue statistics outside the bounds of the universality class of RMT are not completely explained with the deterministic correlations as proposed in previous studies. We study the effect of randomness on deterministic correlations and find that randomness causes a repulsion between deterministic eigenvalues and the random eigenvalues. This is interpreted as a reminiscent of “level repulsion” in RMT and explains some deviations from the previous studies observed in the market data. We also study correlated groups of issues in these markets and propose a refined method to identify correlated groups based on RMT. Some characteristic differences between properties of Tokyo Stock Exchange and New York Stock Exchange are found.

  11. Treatment motivation in drug users: a theory-based analysis.

    PubMed

    Longshore, Douglas; Teruya, Cheryl

    2006-02-01

    Motivation for drug use treatment is widely regarded as crucial to a client's engagement in treatment and success in quitting drug use. Motivation is typically measured with items reflecting high treatment readiness (e.g., perceived need for treatment and commitment to participate) and low treatment resistance (e.g., skepticism regarding benefits of treatment). Building upon reactance theory and the psychotherapeutic construct of resistance, we conceptualized these two aspects of treatment motivation - readiness and resistance - as distinct constructs and examined their predictive power in a sample of 1295 drug-using offenders referred to treatment while on probation. The sample was 60.7% African Americans, 33.5% non-Hispanic Whites, and 21.2% women; their ages ranged from 16 to 63 years old. Interviews occurred at treatment entry and 6 months later. Readiness (but not resistance) predicted treatment retention during the 6-month period. Resistance (but not readiness) predicted drug use, especially among offenders for whom the treatment referral was coercive. These findings suggest that readiness and resistance should both be assessed among clients entering treatment, especially when the referral is coercive. Intake and counseling protocols should address readiness and resistance separately. PMID:16051447

  12. A Comparison of Measurement Equivalence Methods Based on Confirmatory Factor Analysis and Item Response Theory.

    ERIC Educational Resources Information Center

    Flowers, Claudia P.; Raju, Nambury S.; Oshima, T. C.

    Current interest in the assessment of measurement equivalence emphasizes two methods of analysis, linear, and nonlinear procedures. This study simulated data using the graded response model to examine the performance of linear (confirmatory factor analysis or CFA) and nonlinear (item-response-theory-based differential item function or IRT-Based…

  13. Transactional Analysis as a Conceptual Framework: Directed Individual Study in Contemporary Theories.

    ERIC Educational Resources Information Center

    Richards, Bob

    The theory of transactional analysis (TA) originated by Eric Berne in the 1950's is typified by structural analysis and is comprised of the ego states of Parent, Adult, and Child. Linkages are the life scripts of the individual. One ego state is usually in control at any given time. Pathology results when ego boundaries become rigid or break down…

  14. Application of Morse Theory to Analysis of Rayleigh-Taylor Topology

    SciTech Connect

    Miller, P L; Bremer, P T; Cabot, W H; Cook, A W; Laney, D E; Mascarenhas, A A; Pascucci, V

    2007-01-24

    We present a novel Morse Theory approach for the analysis of the complex topology of the Rayleigh-Taylor mixing layer. We automatically extract bubble structures at multiple scales and identify the resolution of interest. Quantitative analysis of bubble counts over time highlights distinct mixing trends for a high-resolution Direct Numerical Simulation (DNS) [1].

  15. Micromechanics-Based Progressive Failure Analysis of Composite Laminates Using Different Constituent Failure Theories

    NASA Technical Reports Server (NTRS)

    Moncada, Albert M.; Chattopadhyay, Aditi; Bednarcyk, Brett A.; Arnold, Steven M.

    2008-01-01

    Predicting failure in a composite can be done with ply level mechanisms and/or micro level mechanisms. This paper uses the Generalized Method of Cells and High-Fidelity Generalized Method of Cells micromechanics theories, coupled with classical lamination theory, as implemented within NASA's Micromechanics Analysis Code with Generalized Method of Cells. The code is able to implement different failure theories on the level of both the fiber and the matrix constituents within a laminate. A comparison is made among maximum stress, maximum strain, Tsai-Hill, and Tsai-Wu failure theories. To verify the failure theories the Worldwide Failure Exercise (WWFE) experiments have been used. The WWFE is a comprehensive study that covers a wide range of polymer matrix composite laminates. The numerical results indicate good correlation with the experimental results for most of the composite layups, but also point to the need for more accurate resin damage progression models.

  16. Elastically cooperative activated barrier hopping theory of relaxation in viscous fluids. II. Thermal liquids.

    PubMed

    Mirigian, Stephen; Schweizer, Kenneth S

    2014-05-21

    Building on the elastically collective nonlinear Langevin equation theory developed for hard spheres in Paper I, we propose and implement a quasi-universal theory for the alpha relaxation of thermal liquids based on mapping them to an effective hard sphere fluid via the dimensionless compressibility. The result is a zero adjustable parameter theory that can quantitatively address in a unified manner the alpha relaxation time over 14 or more decades. The theory has no singularities above zero Kelvin, and relaxation in the equilibrium low temperature limit is predicted to be of a roughly Arrhenius form. The two-barrier (local cage and long range collective elastic) description results in a rich dynamic behavior including apparent Arrhenius, narrow crossover, and deeply supercooled regimes, and multiple characteristic or crossover times and temperatures of clear physical meaning. Application of the theory to nonpolar molecules, alcohols, rare gases, and liquids metals is carried out. Overall, the agreement with experiment is quite good for the temperature dependence of the alpha time, plateau shear modulus, and Boson-like peak frequency for van der Waals liquids, though less so for hydrogen-bonding molecules. The theory predicts multiple growing length scales upon cooling, which reflect distinct aspects of the coupled local hopping and cooperative elastic physics. Calculations of the growth with cooling of an activation volume, which is strongly correlated with a measure of dynamic cooperativity, agree quantitatively with experiment. Comparisons with elastic, entropy crisis, dynamic facilitation, and other approaches are performed, and a fundamental basis for empirically extracted crossover temperatures is established. The present work sets the stage for addressing distinctive glassy phenomena in polymer melts, and diverse liquids under strong confinement. PMID:24852550

  17. Athermal shear-transformation-zone theory of amorphous plastic deformation. II. Analysis of simulated amorphous silicon

    NASA Astrophysics Data System (ADS)

    Bouchbinder, Eran; Langer, J. S.; Procaccia, Itamar

    2007-03-01

    In the preceding paper, we developed an athermal shear-transformation-zone (STZ) theory of amorphous plasticity. Here we use this theory in an analysis of numerical simulations of plasticity in amorphous silicon by Demkowicz and Argon (DA). In addition to bulk mechanical properties, those authors observed internal features of their deforming system that challenge our theory in important ways. We propose a quasithermodynamic interpretation of their observations in which the effective disorder temperature, generated by mechanical deformation well below the glass temperature, governs the behavior of other state variables that fall in and out of equilibrium with it. Our analysis points to a limitation of either the step-strain procedure used by DA in their simulations, or the STZ theory in its ability to describe rapid transients in stress-strain curves, or perhaps to both. Once we allow for this limitation, we are able to bring our theoretical predictions into accurate agreement with the simulations.

  18. A quasi-linear control theory analysis of timesharing skills

    NASA Technical Reports Server (NTRS)

    Agarwal, G. C.; Gottlieb, G. L.

    1977-01-01

    The compliance of the human ankle joint is measured by applying 0 to 50 Hz band-limited gaussian random torques to the foot of a seated human subject. These torques rotate the foot in a plantar-dorsal direction about a horizontal axis at a medial moleolus of the ankle. The applied torques and the resulting angular rotation of the foot are measured, digitized and recorded for off-line processing. Using such a best-fit, second-order model, the effective moment of inertia of the ankle joint, the angular viscosity and the stiffness are calculated. The ankle joint stiffness is shown to be a linear function of the level of tonic muscle contraction, increasing at a rate of 20 to 40 Nm/rad/Kg.m. of active torque. In terms of the muscle physiology, the more muscle fibers that are active, the greater the muscle stiffness. Joint viscosity also increases with activation. Joint stiffness is also a linear function of the joint angle, increasing at a rate of about 0.7 to 1.1 Nm/rad/deg from plantar flexion to dorsiflexion rotation.

  19. Statistical theory and methodology for remote sensing data analysis

    NASA Technical Reports Server (NTRS)

    Odell, P. L.

    1974-01-01

    A model is developed for the evaluation of acreages (proportions) of different crop-types over a geographical area using a classification approach and methods for estimating the crop acreages are given. In estimating the acreages of a specific croptype such as wheat, it is suggested to treat the problem as a two-crop problem: wheat vs. nonwheat, since this simplifies the estimation problem considerably. The error analysis and the sample size problem is investigated for the two-crop approach. Certain numerical results for sample sizes are given for a JSC-ERTS-1 data example on wheat identification performance in Hill County, Montana and Burke County, North Dakota. Lastly, for a large area crop acreages inventory a sampling scheme is suggested for acquiring sample data and the problem of crop acreage estimation and the error analysis is discussed.

  20. Theory of reliable systems. [systems analysis and design

    NASA Technical Reports Server (NTRS)

    Meyer, J. F.

    1973-01-01

    The analysis and design of reliable systems are discussed. The attributes of system reliability studied are fault tolerance, diagnosability, and reconfigurability. Objectives of the study include: to determine properties of system structure that are conducive to a particular attribute; to determine methods for obtaining reliable realizations of a given system; and to determine how properties of system behavior relate to the complexity of fault tolerant realizations. A list of 34 references is included.

  1. Adult Attachment Ratings (AAR): an item response theory analysis.

    PubMed

    Pilkonis, Paul A; Kim, Yookyung; Yu, Lan; Morse, Jennifer Q

    2014-01-01

    The Adult Attachment Ratings (AAR) include 3 scales for anxious, ambivalent attachment (excessive dependency, interpersonal ambivalence, and compulsive care-giving), 3 for avoidant attachment (rigid self-control, defensive separation, and emotional detachment), and 1 for secure attachment. The scales include items (ranging from 6-16 in their original form) scored by raters using a 3-point format (0 = absent, 1 = present, and 2 = strongly present) and summed to produce a total score. Item response theory (IRT) analyses were conducted with data from 414 participants recruited from psychiatric outpatient, medical, and community settings to identify the most informative items from each scale. The IRT results allowed us to shorten the scales to 5-item versions that are more precise and easier to rate because of their brevity. In general, the effective range of measurement for the scales was 0 to +2 SDs for each of the attachment constructs; that is, from average to high levels of attachment problems. Evidence for convergent and discriminant validity of the scales was investigated by comparing them with the Experiences of Close Relationships-Revised (ECR-R) scale and the Kobak Attachment Q-sort. The best consensus among self-reports on the ECR-R, informant ratings on the ECR-R, and expert judgments on the Q-sort and the AAR emerged for anxious, ambivalent attachment. Given the good psychometric characteristics of the scale for secure attachment, however, this measure alone might provide a simple alternative to more elaborate procedures for some measurement purposes. Conversion tables are provided for the 7 scales to facilitate transformation from raw scores to IRT-calibrated (theta) scores. PMID:24033268

  2. Sensitivity analysis of coexistence in ecological communities: theory and application.

    PubMed

    Barabás, György; Pásztor, Liz; Meszéna, Géza; Ostling, Annette

    2014-12-01

    Sensitivity analysis, the study of how ecological variables of interest respond to changes in external conditions, is a theoretically well-developed and widely applied approach in population ecology. Though the application of sensitivity analysis to predicting the response of species-rich communities to disturbances also has a long history, derivation of a mathematical framework for understanding the factors leading to robust coexistence has only been a recent undertaking. Here we suggest that this development opens up a new perspective, providing advances ranging from the applied to the theoretical. First, it yields a framework to be applied in specific cases for assessing the extinction risk of community modules in the face of environmental change. Second, it can be used to determine trait combinations allowing for coexistence that is robust to environmental variation, and limits to diversity in the presence of environmental variation, for specific community types. Third, it offers general insights into the nature of communities that are robust to environmental variation. We apply recent community-level extensions of mathematical sensitivity analysis to example models for illustration. We discuss the advantages and limitations of the method, and some of the empirical questions the theoretical framework could help answer. PMID:25252135

  3. Discriminant analysis in wildlife research: Theory and applications

    USGS Publications Warehouse

    Williams, B.K.

    1981-01-01

    Discriminant analysis, a method of analyzing grouped multivariate data, is often used in ecological investigations. It has both a predictive and an explanatory function, the former aiming at classification of individuals of unknown group membership. The goal of the latter function is to exhibit group separation by means of linear transforms, and the corresponding method is called canonical analysis. This discussion focuses on the application of canonical analysis in ecology. In order to clarify its meaning, a parametric approach is taken instead of the usual data-based formulation. For certain assumptions the data-based canonical variates are shown to result from maximum likelihood estimation, thus insuring consistency and asymptotic efficiency. The distorting effects of covariance heterogeneity are examined, as are certain difficulties which arise in interpreting the canonical functions. A 'distortion metric' is defined, by means of which distortions resulting from the canonical transformation can be assessed. Several sampling problems which arise in ecological applications are considered. It is concluded that the method may prove valuable for data exploration, but is of limited value as an inferential procedure.

  4. Theory of simple biochemical ``shape recognition'' via diffusion from activator coated nanoshapes

    NASA Astrophysics Data System (ADS)

    Daniels, D. R.

    2008-09-01

    Inspired by recent experiments, we model the shape sensitivity, via a typical threshold initiation response, of an underlying complex biochemical reaction network to activator coated nanoshapes. Our theory re-emphasizes that shape effects can be vitally important for the onset of functional behavior in nanopatches and nanoparticles. For certain critical or particular shapes, activator coated nanoshapes do not evoke a threshold response in a complex biochemical network setting, while for different critical or specific shapes, the threshold response is rapidly achieved. The model thus provides a general theoretical understanding for how activator coated nanoshapes can enable a chemical system to perform simple "shape recognition," with an associated "all or nothing" response. The novel and interesting cases of the chemical response due to a nanoshape that shrinks with time is additionally considered, as well as activator coated nanospheres. Possible important applications of this work include the initiation of blood clotting by nanoshapes, nanoshape effects in nanocatalysis, physiological toxicity to nanoparticles, as well as nanoshapes in nanomedicine, drug delivery, and T cell immunological response. The aim of the theory presented here is that it inspires further experimentation on simple biochemical shape recognition via diffusion from activator coated nanoshapes.

  5. Men's passage to fatherhood: an analysis of the contemporary relevance of transition theory.

    PubMed

    Draper, Jan

    2003-03-01

    This paper presents a theoretical analysis of men's experiences of pregnancy, birth and early fatherhood. It does so using a framework of ritual transition theory and argues that despite its earlier structural-functionalist roots, transition theory remains a valuable framework, illuminating contemporary transitions across the life course. The paper discusses the historical development of transition or ritual theory and, drawing upon data generated during longitudinal ethnographic interviews with men undergoing the transition to fatherhood, analyses its relevance in understanding contemporary experiences of fatherhood. PMID:12622806

  6. Comparative Sensitivity Analysis of Muscle Activation Dynamics

    PubMed Central

    Rockenfeller, Robert; Günther, Michael; Schmitt, Syn; Götz, Thomas

    2015-01-01

    We mathematically compared two models of mammalian striated muscle activation dynamics proposed by Hatze and Zajac. Both models are representative for a broad variety of biomechanical models formulated as ordinary differential equations (ODEs). These models incorporate parameters that directly represent known physiological properties. Other parameters have been introduced to reproduce empirical observations. We used sensitivity analysis to investigate the influence of model parameters on the ODE solutions. In addition, we expanded an existing approach to treating initial conditions as parameters and to calculating second-order sensitivities. Furthermore, we used a global sensitivity analysis approach to include finite ranges of parameter values. Hence, a theoretician striving for model reduction could use the method for identifying particularly low sensitivities to detect superfluous parameters. An experimenter could use it for identifying particularly high sensitivities to improve parameter estimation. Hatze's nonlinear model incorporates some parameters to which activation dynamics is clearly more sensitive than to any parameter in Zajac's linear model. Other than Zajac's model, Hatze's model can, however, reproduce measured shifts in optimal muscle length with varied muscle activity. Accordingly we extracted a specific parameter set for Hatze's model that combines best with a particular muscle force-length relation. PMID:26417379

  7. Comparative Sensitivity Analysis of Muscle Activation Dynamics.

    PubMed

    Rockenfeller, Robert; Günther, Michael; Schmitt, Syn; Götz, Thomas

    2015-01-01

    We mathematically compared two models of mammalian striated muscle activation dynamics proposed by Hatze and Zajac. Both models are representative for a broad variety of biomechanical models formulated as ordinary differential equations (ODEs). These models incorporate parameters that directly represent known physiological properties. Other parameters have been introduced to reproduce empirical observations. We used sensitivity analysis to investigate the influence of model parameters on the ODE solutions. In addition, we expanded an existing approach to treating initial conditions as parameters and to calculating second-order sensitivities. Furthermore, we used a global sensitivity analysis approach to include finite ranges of parameter values. Hence, a theoretician striving for model reduction could use the method for identifying particularly low sensitivities to detect superfluous parameters. An experimenter could use it for identifying particularly high sensitivities to improve parameter estimation. Hatze's nonlinear model incorporates some parameters to which activation dynamics is clearly more sensitive than to any parameter in Zajac's linear model. Other than Zajac's model, Hatze's model can, however, reproduce measured shifts in optimal muscle length with varied muscle activity. Accordingly we extracted a specific parameter set for Hatze's model that combines best with a particular muscle force-length relation. PMID:26417379

  8. Using the Dempster-Shafer theory of evidence with a revised lattice structure for activity recognition.

    PubMed

    Liao, Jing; Bi, Yaxin; Nugent, Chris

    2011-01-01

    This paper explores a sensor fusion method applied within smart homes used for the purposes of monitoring human activities in addition to managing uncertainty in sensor-based readings. A three-layer lattice structure has been proposed, which can be used to combine the mass functions derived from sensors along with sensor context. The proposed model can be used to infer activities. Following evaluation of the proposed methodology it has been demonstrated that the Dempster-Shafer theory of evidence can incorporate the uncertainty derived from the sensor errors and the sensor context and subsequently infer the activity using the proposed lattice structure. The results from this study show that this method can detect a toileting activity within a smart home environment with an accuracy of 88.2%. PMID:21075728

  9. Neutron activation analysis in archaeological chemistry

    SciTech Connect

    Harbottle, G.

    1987-01-01

    Neutron activation analysis has proven to be a convenient way of performing the chemical analysis of archaeologically-excavated artifacts and materials. It is fast and does not require tedious laboratory operations. It is multielement, sensitive, and can be made nondestructive. Neutron activation analysis in its instrumental form, i.e., involving no chemical separation, is ideally suited to automation and conveniently takes the first step in data flow patterns that are appropriate for many taxonomic and statistical operations. The future will doubtless see improvements in the practice of NAA in general, but in connection with archaeological science the greatest change will be the filling, interchange and widespread use of data banks based on compilations of analytical data. Since provenience-oriented data banks deal with materials (obsidian, ceramics, metals, semiprecious stones, building materials and sculptural media) that participated in trade networks, the analytical data is certain to be of interest to a rather broad group of archaeologists. It is to meet the needs of the whole archaeological community that archaeological chemistry must now turn.

  10. Activity Theory: Quest for the Unattainable and Hope for the Future (Reply to Commentaries).

    PubMed

    Mironenko, Irina A

    2016-09-01

    In reference to commentaries on the paper (Mammen and Mironenko, Integrative Psychological and Behavioral Science 49(4):681-713, 2015) some clarifications are introduced concerning the general landmarks and objectives in the development of psychological science, in respect to which activity theories (AT) can be assessed and evaluated. Contemporary psychological science is developing along the path of integration, as part of the emerging global world. AT has some special value and importance in this respect. It can contribute to the development of the emerging multi-paradigmatic system of the global psychological science because it combines two aspirations, which are rarely combined in psychological theories: a) consistent focus on scientific method, objectivity and conclusiveness; b) the pursuit of a holistic and complete, not simplified and not one-sided comprehension of the subject. The former provides good bases for dialogue with "objective" psychological approaches, close to natural sciences. The latter is suggesting dialogue with teleological humanitarian psychologies. Therefore, AT can engage in networking with a wide range of theories, facilitating the integration of psychological knowledge. It can contribute to resolve the much discussed collision of reductionist "scientific" theoretical models and loose "comprehensive" descriptions in contemporary psychological science. Developing dialogue and cooperation with other schools is of special importance for the RAT, which should return to the international science, where it was rooted, overcoming the language and conceptual barriers. Some new considerations are suggested regarding the theory of the two types of categories of Jens Mammen. PMID:27283077

  11. An active feedback flow control theory of the vortex breakdown process

    NASA Astrophysics Data System (ADS)

    Granata, Joshua

    An active feedback flow control theory of the vortex breakdown process in incompressible, axisymmetric swirling flows in a finite-length, straight, circular pipe is developed. Flow injection distributed along the pipe wall is used as the controller. The flow is subjected to non-periodic inlet and outlet conditions. A long-wave asymptotic analysis, which involves a re-scaling of the axial distance and time at near critical swirl ratios, results in a nonlinear model problem for the dynamics and control of both inviscid and high-Reynolds number, Re, flows. The approach provides the bifurcation diagram of steady states and the stability characteristics of these states. Computed examples of the flow dynamics based on the full Euler and Navier-Stokes formulations at various swirl levels demonstrate the evolution to near-steady breakdown states when swirl is above a critical level which depends on Re. Numerical stability and mesh convergence studies performed on the inviscid and high-Re flow simulations ensure the accuracy of the computations and the agreement with the theoretical approaches. In addition, an energy analysis of the nonlinear model problem sheds insight into the mechanisms of the flow dynamics which lead to vortex breakdown and suggests a feedback control law which relates the flow injection and the evolving maximum radial velocity at the inlet. Moreover, applying the proposed feedback control law during flow evolution, shows for the first time the successful and robust elimination of the breakdown states and flow stabilization on an almost columnar state for a wide range of swirl up to 53 percent above the first critical level for the inviscid flow case and for a range of swirl up to 15 percent above the first critical level for viscous flows. The control law can be improved for a lower momentary maximum flux injection through the use of discrete injection regions along the pipe. The feedback control cuts the natural feed-forward mechanism of the breakdown

  12. Parsing the neural correlates of moral cognition: ALE meta-analysis on morality, theory of mind, and empathy.

    PubMed

    Bzdok, Danilo; Schilbach, Leonhard; Vogeley, Kai; Schneider, Karla; Laird, Angela R; Langner, Robert; Eickhoff, Simon B

    2012-10-01

    Morally judicious behavior forms the fabric of human sociality. Here, we sought to investigate neural activity associated with different facets of moral thought. Previous research suggests that the cognitive and emotional sources of moral decisions might be closely related to theory of mind, an abstract-cognitive skill, and empathy, a rapid-emotional skill. That is, moral decisions are thought to crucially refer to other persons' representation of intentions and behavioral outcomes as well as (vicariously experienced) emotional states. We thus hypothesized that moral decisions might be implemented in brain areas engaged in 'theory of mind' and empathy. This assumption was tested by conducting a large-scale activation likelihood estimation (ALE) meta-analysis of neuroimaging studies, which assessed 2,607 peak coordinates from 247 experiments in 1,790 participants. The brain areas that were consistently involved in moral decisions showed more convergence with the ALE analysis targeting theory of mind versus empathy. More specifically, the neurotopographical overlap between morality and empathy disfavors a role of affective sharing during moral decisions. Ultimately, our results provide evidence that the neural network underlying moral decisions is probably domain-global and might be dissociable into cognitive and affective sub-systems. PMID:22270812

  13. Analysis of supercritical vapor explosions using thermal detonation wave theory

    SciTech Connect

    Shamoun, B.I.; Corradini, M.L.

    1995-09-01

    The interaction of certain materials such as Al{sub 2}O{sub 3} with water results in vapor explosions with very high (supercritical) pressures and propagation velocities. A quasi-steady state analysis of supercritical detonation in one-dimensional multiphase flow was applied to analyze experimental data of the KROTOS (26-30) set of experiments conducted at the Joint Research Center at Ispra, Italy. In this work we have applied a new method of solution which allows for partial fragmentation of the fuel in the shock adiabatic thermodynamic model. This method uses known experiment values of the shock pressure and propagation velocity to estimate the initial mixing conditions of the experiment. The fuel and coolant were both considered compressible in this analysis. In KROTOS 26, 28, 29, and 30 the measured values of the shock pressure by the experiment were found to be higher than 25, 50, 100, and 100 Mpa respectively. Using the above data for the wave velocity and our best estimate for the values of the pressure, the predicted minimum values of the fragmented mass of the fuel were found to be 0.026. 0.04, 0.057, and 0.068 kg respectively. The predicted values of the work output corresponding to the above fragmented masses of the fuel were found to be 40, 84, 126, and 150 kJ respectively, with predicted initial void fractions of 112%, 12.5%, 8%, and 6% respectively.

  14. Analysis of DOE international environmental management activities

    SciTech Connect

    Ragaini, R.C.

    1995-09-01

    The Department of Energy`s (DOE) Strategic Plan (April 1994) states that DOE`s long-term vision includes world leadership in environmental restoration and waste management activities. The activities of the DOE Office of Environmental Management (EM) can play a key role in DOE`s goals of maintaining U.S. global competitiveness and ensuring the continuation of a world class science and technology community. DOE`s interest in attaining these goals stems partly from its participation in organizations like the Trade Policy Coordinating Committee (TPCC), with its National Environmental Export Promotion Strategy, which seeks to strengthen U.S. competitiveness and the building of public-private partnerships as part of U.S. industrial policy. The International Interactions Field Office task will build a communication network which will facilitate the efficient and effective communication between DOE Headquarters, Field Offices, and contractors. Under this network, Headquarters will provide the Field Offices with information on the Administration`s policies and activities (such as the DOE Strategic Plan), interagency activities, as well as relevant information from other field offices. Lawrence Livermore National Laboratory (LLNL) will, in turn, provide Headquarters with information on various international activities which, when appropriate, will be included in reports to groups like the TPCC and the EM Focus Areas. This task provides for the collection, review, and analysis of information on the more significant international environmental restoration and waste management initiatives and activities which have been used or are being considered at LLNL. Information gathering will focus on efforts and accomplishments in meeting the challenges of providing timely and cost effective cleanup of its environmentally damaged sites and facilities, especially through international technical exchanges and/or the implementation of foreign-development technologies.

  15. Scalable histopathological image analysis via active learning.

    PubMed

    Zhu, Yan; Zhang, Shaoting; Liu, Wei; Metaxas, Dimitris N

    2014-01-01

    Training an effective and scalable system for medical image analysis usually requires a large amount of labeled data, which incurs a tremendous annotation burden for pathologists. Recent progress in active learning can alleviate this issue, leading to a great reduction on the labeling cost without sacrificing the predicting accuracy too much. However, most existing active learning methods disregard the "structured information" that may exist in medical images (e.g., data from individual patients), and make a simplifying assumption that unlabeled data is independently and identically distributed. Both may not be suitable for real-world medical images. In this paper, we propose a novel batch-mode active learning method which explores and leverages such structured information in annotations of medical images to enforce diversity among the selected data, therefore maximizing the information gain. We formulate the active learning problem as an adaptive submodular function maximization problem subject to a partition matroid constraint, and further present an efficient greedy algorithm to achieve a good solution with a theoretically proven bound. We demonstrate the efficacy of our algorithm on thousands of histopathological images of breast microscopic tissues. PMID:25320821

  16. Dating violence, social learning theory, and gender: a multivariate analysis.

    PubMed

    Tontodonato, P; Crew, B K

    1992-01-01

    The study of violence between dating partners is a logical extension of interest in marital violence. However, little of this research tests explanations of intimate violence using multivariate techniques, and only recently have such tests occurred within a theoretical framework. Drawing on a recent social learning model of courtship violence (Riggs & O'Leary, 1989), this paper empirically examines constructs hypothesized to be predictive of the use of dating violence and investigates possible gender differences in the underlying causal structure of such violence. Logit analysis indicates that parent-child violence, drug use, and knowledge of use of dating violence by others predict the use of courtship violence by females. Belief that violence between intimates is justifiable, drug use, and parental divorce are related to perpetration of dating aggression by males. Explanations for these results and the importance of a multivariate approach to the problem are discussed. PMID:1504032

  17. An information theory analysis of spatial decisions in cognitive development

    PubMed Central

    Scott, Nicole M.; Sera, Maria D.; Georgopoulos, Apostolos P.

    2015-01-01

    Performance in a cognitive task can be considered as the outcome of a decision-making process operating across various knowledge domains or aspects of a single domain. Therefore, an analysis of these decisions in various tasks can shed light on the interplay and integration of these domains (or elements within a single domain) as they are associated with specific task characteristics. In this study, we applied an information theoretic approach to assess quantitatively the gain of knowledge across various elements of the cognitive domain of spatial, relational knowledge, as a function of development. Specifically, we examined changing spatial relational knowledge from ages 5 to 10 years. Our analyses consisted of a two-step process. First, we performed a hierarchical clustering analysis on the decisions made in 16 different tasks of spatial relational knowledge to determine which tasks were performed similarly at each age group as well as to discover how the tasks clustered together. We next used two measures of entropy to capture the gradual emergence of order in the development of relational knowledge. These measures of “cognitive entropy” were defined based on two independent aspects of chunking, namely (1) the number of clusters formed at each age group, and (2) the distribution of tasks across the clusters. We found that both measures of entropy decreased with age in a quadratic fashion and were positively and linearly correlated. The decrease in entropy and, therefore, gain of information during development was accompanied by improved performance. These results document, for the first time, the orderly and progressively structured “chunking” of decisions across the development of spatial relational reasoning and quantify this gain within a formal information-theoretic framework. PMID:25698915

  18. An information theory analysis of spatial decisions in cognitive development.

    PubMed

    Scott, Nicole M; Sera, Maria D; Georgopoulos, Apostolos P

    2015-01-01

    Performance in a cognitive task can be considered as the outcome of a decision-making process operating across various knowledge domains or aspects of a single domain. Therefore, an analysis of these decisions in various tasks can shed light on the interplay and integration of these domains (or elements within a single domain) as they are associated with specific task characteristics. In this study, we applied an information theoretic approach to assess quantitatively the gain of knowledge across various elements of the cognitive domain of spatial, relational knowledge, as a function of development. Specifically, we examined changing spatial relational knowledge from ages 5 to 10 years. Our analyses consisted of a two-step process. First, we performed a hierarchical clustering analysis on the decisions made in 16 different tasks of spatial relational knowledge to determine which tasks were performed similarly at each age group as well as to discover how the tasks clustered together. We next used two measures of entropy to capture the gradual emergence of order in the development of relational knowledge. These measures of "cognitive entropy" were defined based on two independent aspects of chunking, namely (1) the number of clusters formed at each age group, and (2) the distribution of tasks across the clusters. We found that both measures of entropy decreased with age in a quadratic fashion and were positively and linearly correlated. The decrease in entropy and, therefore, gain of information during development was accompanied by improved performance. These results document, for the first time, the orderly and progressively structured "chunking" of decisions across the development of spatial relational reasoning and quantify this gain within a formal information-theoretic framework. PMID:25698915

  19. Minimizing the dysfunctional interplay between activity and recovery: A grounded theory on living with fibromyalgia

    PubMed Central

    Hallberg, Lillemor R.-M.; Bergman, Stefan

    2011-01-01

    The aim of this study was to generate a substantive theory, based on interviews with women with fibromyalgia, explaining how they manage their main concerns in daily life. The study has an inductive approach in line with classic grounded theory (Glaser, 1992). Twenty-three women living in the southwest region of Sweden were interviewed in-depth about their daily living with fibromyalgia and problems related to this. Probing and follow-up questions were asked by the interviewers when relevant. The interviews were transcribed verbatim and consecutively analysed in line with guidelines for grounded theory. The results showed that the main concern for women with fibromyalgia was to reach a balance in daily life. This concern was resolved by them using different strategies aimed at minimizing the dysfunctional interplay between activity and recovery (core category). This imbalance includes that the women are forcing themselves to live a fast-paced life and thereby tax or exceed their physical and psychological abilities and limits. Generally, the fibromyalgia symptoms vary and are most often unpredictable to the women. Pain and fatigue are the most prominent symptoms. However, pain-free periods occur, often related to intense engagement in some activity, relaxation or joy, but mainly the “pain gaps” are unpredictable. To reach a balance in daily life and manage the dysfunctional interplay between activity and recovery the women use several strategies. They are avoiding unnecessary stress, utilizing good days, paying the price for allowing oneself too much activity, planning activities in advance, distracting oneself from the pain, engaging in alleviating physical activities, and ignoring pain sensations. Distracting from the pain seems to be an especially helpful strategy as it may lead to “pain gaps”. This strategy, meaning to divert attention from the pain, is possible to learn, or improve, in health promoting courses based on principles of cognitive

  20. Pavlov's conceptualization of the dynamic stereotype in the theory of higher nervous activity.

    PubMed

    Windholz, G

    1996-01-01

    David Joravsky (1989) alleges that Ivan Petrovich Pavlov's theory of higher nervous activity fails to explain "most forms of complex behavior" because establishment of second-order and third-order chains of conditional reflexes was not feasible. Yet, Pavlov (1951a), relying on experimental evidence, some of which is presented, held that the interaction of higher organisms with the external environment was based on the dynamic stereotype, that is, on the integration in the cortical hemispheres of neural traces coming from the external and internal environments. In its formulation in the 1930s, Pavlov's theory was dynamic, not associative. It postulated the synthesis of conditioned reflexes, not associative chains of conditioned reflexes. PMID:8644888

  1. Graph theory and stability analysis of protein complex interaction networks.

    PubMed

    Huang, Chien-Hung; Chen, Teng-Hung; Ng, Ka-Lok

    2016-04-01

    Protein complexes play an essential role in many biological processes. Complexes can interact with other complexes to form protein complex interaction network (PCIN) that involves in important cellular processes. There are relatively few studies on examining the interaction topology among protein complexes; and little is known about the stability of PCIN under perturbations. We employed graph theoretical approach to reveal hidden properties and features of four species PCINs. Two main issues are addressed, (i) the global and local network topological properties, and (ii) the stability of the networks under 12 types of perturbations. According to the topological parameter classification, we identified some critical protein complexes and validated that the topological analysis approach could provide meaningful biological interpretations of the protein complex systems. Through the Kolmogorov-Smimov test, we showed that local topological parameters are good indicators to characterise the structure of PCINs. We further demonstrated the effectiveness of the current approach by performing the scalability and data normalization tests. To measure the robustness of PCINs, we proposed to consider eight topological-based perturbations, which are specifically applicable in scenarios of targeted, sustained attacks. We found that the degree-based, betweenness-based and brokering-coefficient-based perturbations have the largest effect on network stability. PMID:26997661

  2. Electrodermal activity analysis during affective haptic elicitation.

    PubMed

    Greco, Alberto; Valenza, Gaetano; Nardelli, Mimma; Bianchi, Matteo; Lanata, Antonio; Scilingo, Enzo Pasquale

    2015-08-01

    This paper investigates how the autonomic nervous system dynamics, quantified through the analysis of the electrodermal activity (EDA), is modulated according to affective haptic stimuli. Specifically, a haptic display able to convey caress-like stimuli is presented to 32 healthy subjects (16 female). Each stimulus is changed according to six combinations of three velocities and two forces levels of two motors stretching a strip of fabric. Subjects were also asked to score each stimulus in terms of arousal (high/low activation) and valence (pleasant/unpleasant), in agreement with the circumplex model of affect. EDA was processed using a deconvolutive method, separating tonic and phasic components. A statistical analysis was performed in order to identify significant differences in EDA features among force and velocity levels, as well as in their valence and arousal scores. Results show that the simulated caress induced by the haptic display significantly affects the EDA. In detail, the phasic component seems to be inversely related to the valence score. This finding is new and promising, since it can be used, e.g., as an additional cue for haptics design. PMID:26737605

  3. Physical activity adoption to adherence, lapse, and dropout: a self-determination theory perspective.

    PubMed

    Kinnafick, Florence-Emilie; Thøgersen-Ntoumani, Cecilie; Duda, Joan L

    2014-05-01

    Grounded in Self-Determination Theory, we aimed to explore and identify key motivational processes involved in the transition from a physically inactive to an active lifestyle, and the processes involved in lapse and dropout behavior within a walking program. We implemented a qualitative, longitudinal case study method, using semistructured interviews and theoretical thematic analyses. Fifteen women were interviewed over 10 months and three profiles were generated: (a) nonadherence, (b) lapse/readoption of physical activity, and (c) adherence. Internalization of walking behavior was key to adherence. Satisfaction of the needs for competence and relatedness were central for participation during exercise at the adoption stages, and autonomy was particularly pertinent in facilitating adherence. Those who lapsed and restarted physical activity experienced feelings of autonomy at the point of readoption. Sources of support were driving forces in the adoption and adherence phases. PMID:24692183

  4. Temporal self-regulation theory: a neurobiologically informed model for physical activity behavior

    PubMed Central

    Hall, Peter A.; Fong, Geoffrey T.

    2015-01-01

    Dominant explanatory models for physical activity behavior are limited by the exclusion of several important components, including temporal dynamics, ecological forces, and neurobiological factors. The latter may be a critical omission, given the relevance of several aspects of cognitive function for the self-regulatory processes that are likely required for consistent implementation of physical activity behavior in everyday life. This narrative review introduces temporal self-regulation theory (TST; Hall and Fong, 2007, 2013) as a new explanatory model for physical activity behavior. Important features of the model include consideration of the default status of the physical activity behavior, as well as the disproportionate influence of temporally proximal behavioral contingencies. Most importantly, the TST model proposes positive feedback loops linking executive function (EF) and the performance of physical activity behavior. Specifically, those with relatively stronger executive control (and optimized brain structures supporting it, such as the dorsolateral prefrontal cortex (PFC)) are able to implement physical activity with more consistency than others, which in turn serves to strengthen the executive control network itself. The TST model has the potential to explain everyday variants of incidental physical activity, sport-related excellence via capacity for deliberate practice, and variability in the propensity to schedule and implement exercise routines. PMID:25859196

  5. Perturbation theory analysis of competition in a heterogeneous population

    NASA Astrophysics Data System (ADS)

    Utzny, C.; Burroughs, N. J.

    2003-01-01

    A physiologically structured population model of T cell populations at the end of an immune response is proposed and analysed. The proposed model describes a T cell population with a structured death rate mediated by cytokine receptor surface expression. This provides a structuring that determines the ability of a T cell to compete for survival cytokines. Homogeneous differentiation into memory combined with heterogeneous survival abilities leads to a system of nonlinear first-order integro differential equations. The mathematical model is studied analytically by a perturbation approach which agrees well with numerical integrations. We find that the structured death rate leads to selection of T cells expressing high cytokine receptor levels. Selection in this model is independent of the initial T cell distribution which allows us to define a universal selection curve, a property lost under receptor downregulation (i.e. loss of cytokine receptors from the surface). Furthermore, we examine the effects of a population dependent memory differentiation rate and of cytokine receptor downregulation on selection. A population dependent memory differentiation rate increases selection significantly while putting an upper bound on the number of T cells differentiating into memory. Under receptor downregulation a dramatic change of the memory T cell distribution is induced. We find that there exists a critical ratio of the receptor downregulation rate to the average T cell death rate for which selection becomes maximal. Our analysis reveals that this maximum property is the result of an interplay between single cell dynamics and population dynamics. We propose that the selection studied in this paper plays an important role in the selection of optimal T cells for the memory pool.

  6. Numerical investigations on the osseointegration of uncemented endoprostheses based on bio-active interface theory

    NASA Astrophysics Data System (ADS)

    Lutz, André; Nackenhorst, Udo

    2012-09-01

    In order to simulate the osseointegration of bone implants, a bio-active interface theory is necessary. The thin bone-implant interface layer is described by the Drucker-Prager plasticity model. The formulation of bone mineral density depends on the local mechanical environment. For the simulation of the osseointegration of bone implants a bio-active interface theory is suggested. A thin bone-implant interface layer is described by a Drucker-Prager plasticity model. An evolution rule for the bone mineral density is formulated in dependency of the local mechanical environment. The time dependent ingrowth is modeled by a hardening rule which modifies the Drucker-Prager yield-surface cone in the principle stress state in dependency of the local bone mineral density. The osseointegration process is limited by the violation of a so called micromotion threshold. This relative motion in the implant-bone interface is computed by dynamic loads of daily motion activity. For parameter studies on detailed 3D models model reduction techniques are introduced. The applicability is demonstrated on a hip-joint prosthesis which is in clinical usage.

  7. An information theory criteria based blind method for enumerating active users in DS-CDMA system

    NASA Astrophysics Data System (ADS)

    Samsami Khodadad, Farid; Abed Hodtani, Ghosheh

    2014-11-01

    In this paper, a new and blind algorithm for active user enumeration in asynchronous direct sequence code division multiple access (DS-CDMA) in multipath channel scenario is proposed. The proposed method is based on information theory criteria. There are two main categories of information criteria which are widely used in active user enumeration, Akaike Information Criterion (AIC) and Minimum Description Length (MDL) information theory criteria. The main difference between these two criteria is their penalty functions. Due to this difference, MDL is a consistent enumerator which has better performance in higher signal-to-noise ratios (SNR) but AIC is preferred in lower SNRs. In sequel, we propose a SNR compliance method based on subspace and training genetic algorithm to have the performance of both of them. Moreover, our method uses only a single antenna, in difference to the previous methods which decrease hardware complexity. Simulation results show that the proposed method is capable of estimating the number of active users without any prior knowledge and the efficiency of the method.

  8. Density Functional Theory Calculations of Activation Energies for Carrier Capture by Defects in Semiconductors

    NASA Astrophysics Data System (ADS)

    Modine, N. A.; Wright, A. F.; Lee, S. R.

    The rate of defect-induced carrier recombination is determined by both defect levels and carrier capture cross-sections. Density functional theory (DFT) has been widely and successfully used to predict defect levels, but only recently has work begun to focus on using DFT to determine carrier capture cross-sections. Lang and Henry developed the theory of carrier-capture by multiphonon emission in the 1970s and showed that carrier-capture cross-sections differ between defects primarily due to differences in their carrier capture activation energies. We present an approach to using DFT to calculate carrier capture activation energies that does not depend on an assumed configuration coordinate and that fully accounts for anharmonic effects, which can substantially modify carrier activation energies. We demonstrate our approach for intrinisic defects in GaAs and GaN and discuss how our results depend on the choice of exchange-correlation functional and the treatment of spin polarization. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  9. Activity Theory as a Tool to Address the Problem of Chemistry's Lack of Relevance in Secondary School Chemical Education

    ERIC Educational Resources Information Center

    Van Aalsvoort, Joke

    2004-01-01

    In a previous article, the problem of chemistry's lack of relevance in secondary chemical education was analysed using logical positivism as a tool. This article starts with the hypothesis that the problem can be addressed by means of activity theory, one of the important theories within the sociocultural school. The reason for this expectation is…

  10. How Does an Activity Theory Model Help to Know Better about Teaching with Electronic-Exercise-Bases?

    ERIC Educational Resources Information Center

    Abboud-Blanchard, Maha; Cazes, Claire

    2012-01-01

    The research presented in this paper relies on Activity Theory and particularly on Engestrom's model, to better understand the use of Electronic-Exercise-Bases (EEB) by mathematics teachers. This theory provides a holistic approach to illustrate the complexity of the EEB integration. The results highlight reasons and ways of using EEB and show…

  11. Test and theory for piezoelectric actuator-active vibration control of rotating machinery

    NASA Technical Reports Server (NTRS)

    Palazzolo, A. B.; Lin, R. R.; Alexander, R. M.; Kascak, A. F.; Montague, J.

    1989-01-01

    The application of piezoelectric actuators for active vibration control (AVC) of rotating machinery is examined. Theory is derived and the resulting predictions are shown to agree closely with results of tests performed on an air turbine driven-overhung rotor. The test results show significant reduction in unbalance, transient and sub-synchronous responses. Results from a 30-hour endurance test support the AVD system reliability. Various aspects of the electro-mechanical stability of the control system are also discussed and illustrated. Finally, application of the AVC system to an actual jet engine is discussed.

  12. Universality for Moving Stripes: A Hydrodynamic Theory of Polar Active Smectics

    NASA Astrophysics Data System (ADS)

    Chen, Leiming; Toner, John

    2013-08-01

    We present a theory of moving stripes (“polar active smectics”), both with and without number conservation. The latter is described by a compact anisotropic Kardar-Parisi-Zhang equation, which implies smectic order is quasilong ranged in d=2 and long ranged in d=3. In d=2 the smectic disorders via a Kosterlitz-Thouless transition, which can be driven by either increasing the noise or varying certain nonlinearities. For the number-conserving case, giant number fluctuations are greatly suppressed by the smectic order, which is long ranged in d=3. Nonlinear effects become important in d=2.

  13. Predicting physical activity and outcome expectations in cancer survivors: an application of Self-Determination Theory.

    PubMed

    Wilson, Philip M; Blanchard, Chris M; Nehl, Eric; Baker, Frank

    2006-07-01

    The purpose of this study was to examine the contributions of autonomous and controlled motives drawn from Self-Determination Theory (SDT; Intrinsic Motivation and Self-determination in Human Behavior. Plenum Press: New York, 1985; Handbook of Self-determination Research. University of Rochester Press: New York, 2002) towards predicting physical activity behaviours and outcome expectations in adult cancer survivors. Participants were cancer-survivors (N=220) and a non-cancer comparison cohort (N=220) who completed an adapted version of the Treatment Self-Regulation Questionnaire modified for physical activity behaviour (TSRQ-PA), an assessment of the number of minutes engaged in moderate-to-vigorous physical activity (MVPA) weekly, and the anticipated outcomes expected from regular physical activity (OE). Simultaneous multiple regression analyses indicated that autonomous motives was the dominant predictor of OEs across both cancer and non-cancer cohorts (R(2adj)=0.29-0.43), while MVPA was predicted by autonomous (beta's ranged from 0.21 to 0.34) and controlled (beta's ranged from -0.04 to -0.23) motives after controlling for demographic considerations. Cancer status (cancer versus no cancer) did not moderate the motivation-physical activity relationship. Collectively, these findings suggest that the distinction between autonomous and controlled motives is useful and compliments a growing body of evidence supporting SDT as a framework for understanding motivational processes in physical activity contexts with cancer survivors. PMID:16304621

  14. Promoting physical activity: development and testing of self-determination theory-based interventions

    PubMed Central

    2012-01-01

    A growing number of studies have pulled from Deci and Ryan's Self-Determination Theory to design interventions targeting health behavior change. More recently, researchers have begun using SDT to promote the adoption and maintenance of an active lifestyle. In this review, we aim to highlight how researchers and practitioners can draw from the SDT framework to develop, implement, and evaluate intervention efforts centered on increasing physical activity levels in different contexts and different populations. In the present paper, the rationale for using SDT to foster physical activity engagement is briefly reviewed before particular attention is given to three recent randomized controlled trials, the Canadian Physical Activity Counseling (PAC) Trial, the Empower trial from the UK, and the Portuguese PESO (Promotion of Health and Exercise in Obesity) trial, each of which focused on promoting physical activity behavior. The SDT-based intervention components, procedures, and participants are highlighted, and the key findings that have emanated from these three trials are presented. Lastly, we outline some of the limitations of the work conducted to date in this area and we acknowledge the challenges that arise when attempting to design, deliver, and test SDT-grounded interventions in the context of physical activity promotion. PMID:22385751

  15. Predicting Physical Activity of First-Year University Students: An Application of the Theory of Planned Behavior

    ERIC Educational Resources Information Center

    Kwan, Matthew Yiu Wing; Bray, Steven Russell; Ginis, Kathleen Anne Martin

    2009-01-01

    Objective: The purpose of this study was to apply Ajzen's theory of planned behavior (TPB) and a measure of past physical activity behavior to predict first-year students' physical activity intentions and behavior. Participants and Methods: First-year university students (N = 212) completed measures of TPB variables and past physical activity at…

  16. A Polytomous Item Response Theory Analysis of Social Physique Anxiety Scale

    ERIC Educational Resources Information Center

    Fletcher, Richard B.; Crocker, Peter

    2014-01-01

    The present study investigated the social physique anxiety scale's factor structure and item properties using confirmatory factor analysis and item response theory. An additional aim was to identify differences in response patterns between groups (gender). A large sample of high school students aged 11-15 years (N = 1,529) consisting of n =…

  17. Gender Assignment in Contemporary Standard Russian: A Comprehensive Analysis in Optimality Theory

    ERIC Educational Resources Information Center

    Galbreath, Blake Lee Everett

    2010-01-01

    The purpose of this dissertation is to provide a comprehensive analysis of gender assignment in Contemporary Standard Russian within the framework of Optimality Theory (Prince and Smolensky 1993). The result of the dissertation is the establishment of the phonological, morphological, semantic, and faithfulness constraints necessary to assign…

  18. Comparing the Fit of Item Response Theory and Factor Analysis Models

    ERIC Educational Resources Information Center

    Maydeu-Olivares, Alberto; Cai, Li; Hernandez, Adolfo

    2011-01-01

    Linear factor analysis (FA) models can be reliably tested using test statistics based on residual covariances. We show that the same statistics can be used to reliably test the fit of item response theory (IRT) models for ordinal data (under some conditions). Hence, the fit of an FA model and of an IRT model to the same data set can now be…

  19. The Illusion of Inclusion: A Critical Race Theory Textual Analysis of Race and Standards

    ERIC Educational Resources Information Center

    Heilig, Julian Vasquez; Brown, Keffrelyn D.; Brown, Anthony L.

    2012-01-01

    In this article, Julian Vasquez Heilig, Keffrelyn Brown, and Anthony Brown offer findings from a close textual analysis of how the Texas social studies standards address race, racism, and communities of color. Using the lens of critical race theory, the authors uncover the sometimes subtle ways that the standards can appear to adequately address…

  20. Social Cognitive Career Theory, Conscientiousness, and Work Performance: A Meta-Analytic Path Analysis

    ERIC Educational Resources Information Center

    Brown, Steven D.; Lent, Robert W.; Telander, Kyle; Tramayne, Selena

    2011-01-01

    We performed a meta-analytic path analysis of an abbreviated version of social cognitive career theory's (SCCT) model of work performance (Lent, Brown, & Hackett, 1994). The model we tested included the central cognitive predictors of performance (ability, self-efficacy, performance goals), with the exception of outcome expectations. Results…

  1. An Overview of Nonlinear Factor Analysis and Its Relationship to Item Response Theory.

    ERIC Educational Resources Information Center

    De Champlain, Andre

    An approach that is currently gaining popularity in educational measurement is one that treats item response theory (IRT) as a special case of nonlinear factor analysis (NLFA). A brief overview is provided of some of the research that has examined the relationship between IRT and NLFA. Three NLFA models are outlined, emphasizing their major…

  2. Cognitive Structures of the Gifted: Theoretical Perspectives, Factor Analysis, Triarchic Theories of Intelligence, and Insight Issues.

    ERIC Educational Resources Information Center

    Shaughnessy, Michael F.

    1990-01-01

    The paper examines competing models for the thinking processes of gifted students, including the Piagetian model, the Triarchic theory of R. Sternberg, and the varieties of intelligence proposed by H. Gardner. The paper offers a meta-analysis and a six realm domain for the understanding of cognitive processing propensities in gifted students. (DB)

  3. Functional Path Analysis as a Multivariate Technique in Developing a Theory of Participation in Adult Education.

    ERIC Educational Resources Information Center

    Martin, James L.

    This paper reports on attempts by the author to construct a theoretical framework of adult education participation using a theory development process and the corresponding multivariate statistical techniques. Two problems are identified: the lack of theoretical framework in studying problems, and the limiting of statistical analysis to univariate…

  4. The Analysis of Ratings Using Generalizability Theory for Student Outcome Assessment. AIR 1988 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Erwin, T. Dary

    Rating scales are a typical method for evaluating a student's performance in outcomes assessment. The analysis of the quality of information from rating scales poses special measurement problems when researchers work with faculty in their development. Generalizability measurement theory offers a set of techniques for estimating errors or…

  5. Toward a Neo-Deweyan Theory of Curriculum Analysis and Development

    ERIC Educational Resources Information Center

    Simpson, Douglas J.; Almager, Irma L.; Beerwinkle, Andrea L.; Celebi, Dilber; Ferkel, Ricky C.; Holubik, Thomas E.; Reed, Christy A.; Tomlinson, Tracee A.

    2011-01-01

    We adapted an existing comprehensive theory of curriculum analysis for application across complex, multicultural educational environments in P-12 schools. Our theoretical framework is neo-Deweyan in that it draws heavily from John Dewey's curriculum philosophy and because it goes beyond him to draw extensively from other curriculum theorists. The…

  6. A Qualitative Analysis Framework Using Natural Language Processing and Graph Theory

    ERIC Educational Resources Information Center

    Tierney, Patrick J.

    2012-01-01

    This paper introduces a method of extending natural language-based processing of qualitative data analysis with the use of a very quantitative tool--graph theory. It is not an attempt to convert qualitative research to a positivist approach with a mathematical black box, nor is it a "graphical solution". Rather, it is a method to help qualitative…

  7. A Latent Class Analysis of Adolescent Gambling: Application of Resilience Theory

    ERIC Educational Resources Information Center

    Goldstein, Abby L.; Faulkner, Breanne; Cunningham, Rebecca M.; Zimmerman, Marc A.; Chermack, Stephen; Walton, Maureen A.

    2013-01-01

    The current study examined the application of resilience theory to adolescent gambling using Latent Class Analysis (LCA) to establish subtypes of adolescent gamblers and to explore risk and promotive factors associated with gambling group membership. Participants were a diverse sample of 249 adolescents ages 14 to 18 (30.1 % female, 59.4 % African…

  8. Health Behavior Theory for Pressure Ulcer Prevention: Root-Cause Analysis Project in Critical Care Nursing.

    PubMed

    Choi, Kristen R; Ragnoni, Jennifer A; Bickmann, Jonathan D; Saarinen, Hannah A; Gosselin, Ann K

    2016-01-01

    The purpose of this project was to use a behavioral theory to examine pressure ulcer prevention by nurses in a critical care setting. A root-cause analysis approach was used, including an integrative literature review, operationalization of behavioral constructs into a survey, and root-cause analysis application in a cardiovascular intensive care unit. This article highlights an innovative approach to quality improvement in critical care. PMID:26111143

  9. Classical psychoanalysis and object relations theory in the analysis of character.

    PubMed

    Gill, H S

    1990-01-01

    The analysis of character begins with repeated interpretation of its defensive structure and later moves into the analysis of object relations. What appears at first to be a patient's defenses against instinctual impulses may subsequently be recognized as defenses against emotional reactions to early objects. Nevertheless, at the beginning, interpretations should be directed toward the clinical material already available, and not at what may eventually emerge according to the analyst's theory. The author presents a case report to illustrate this viewpoint. PMID:2268755

  10. Unified theory of near-field analysis and measurement - Scattering and inverse scattering

    NASA Astrophysics Data System (ADS)

    Wacker, P. F.

    1981-03-01

    The scanning procedures of unified theory of near-field analysis and measurement are adapted to the determination of scattering patterns of electromagnetic and scalar systems from measurements made in the near, intermediate, or far field, with emphasis on high accuracy and efficient data processing. The scanning procedures include spherical, improved plane polar, and many types of plane rectangular, plane radial, and circular cylindrical scanning. Application of group representation to inverse scattering analysis is discussed.

  11. Deconstructing dementia and delirium hospital practice: using cultural historical activity theory to inform education approaches.

    PubMed

    Teodorczuk, Andrew; Mukaetova-Ladinska, Elizabeta; Corbett, Sally; Welfare, Mark

    2015-08-01

    Older patients with dementia and delirium receive suboptimal hospital care. Policy calls for more effective education to address this though there is little consensus on what this entails. The purpose of this clarification study is to explore how practice gaps are constructed in relation to managing the confused hospitalised older patient. The intent is to inform educational processes in the work-place beyond traditional approaches such as training. Adopting grounded theory as a research method and working within a social constructionist paradigm we explored the practice gaps of 15 healthcare professionals by interview and conducted five focus groups with patients, carers and Liaison mental health professionals. Data were thematically analysed by constant comparison and theoretical sampling was undertaken until saturation reached. Categories were identified and pragmatic concepts developed grounded within the data. Findings were then further analysed using cultural historical activity theory as a deductive lens. Practice gaps in relation to managing the confused older patient are determined by factors operating at individual (knowledge and skill gaps, personal philosophy, task based practice), team (leadership, time and ward environmental factors) and organisational (power relationships, dominance of medical model, fragmentation of care services) levels. Conceptually, practice appeared to be influenced by socio-cultural ward factors and compounded by a failure to join up existing "patient" knowledge amongst professionals. Applying cultural historical activity theory to further illuminate the findings, the central object is defined as learning about the patient and the mediating artifacts are the care relationships. The overarching medical dominance emerges as an important cultural historical factor at play and staff rules and divisions of labour are exposed. Lastly key contradictions and tensions in the system that work against learning about the patient are

  12. Qualitative Data Analysis for Health Services Research: Developing Taxonomy, Themes, and Theory

    PubMed Central

    Bradley, Elizabeth H; Curry, Leslie A; Devers, Kelly J

    2007-01-01

    Objective To provide practical strategies for conducting and evaluating analyses of qualitative data applicable for health services researchers. Data Sources and Design We draw on extant qualitative methodological literature to describe practical approaches to qualitative data analysis. Approaches to data analysis vary by discipline and analytic tradition; however, we focus on qualitative data analysis that has as a goal the generation of taxonomy, themes, and theory germane to health services research. Principle Findings We describe an approach to qualitative data analysis that applies the principles of inductive reasoning while also employing predetermined code types to guide data analysis and interpretation. These code types (conceptual, relationship, perspective, participant characteristics, and setting codes) define a structure that is appropriate for generation of taxonomy, themes, and theory. Conceptual codes and subcodes facilitate the development of taxonomies. Relationship and perspective codes facilitate the development of themes and theory. Intersectional analyses with data coded for participant characteristics and setting codes can facilitate comparative analyses. Conclusions Qualitative inquiry can improve the description and explanation of complex, real-world phenomena pertinent to health services research. Greater understanding of the processes of qualitative data analysis can be helpful for health services researchers as they use these methods themselves or collaborate with qualitative researchers from a wide range of disciplines. PMID:17286625

  13. Active polarimeter optical system laser hazard analysis.

    SciTech Connect

    Augustoni, Arnold L.

    2005-07-01

    A laser hazard analysis was performed for the SNL Active Polarimeter Optical System based on the ANSI Standard Z136.1-2000, American National Standard for Safe Use of Lasers and the ANSI Standard Z136.6-2000, American National Standard for Safe Use of Lasers Outdoors. The Active Polarimeter Optical System (APOS) uses a pulsed, near-infrared, chromium doped lithium strontium aluminum fluoride (Cr:LiSAF) crystal laser in conjunction with a holographic diffuser and lens to illuminate a scene of interest. The APOS is intended for outdoor operations. The system is mounted on a height adjustable platform (6 feet to 40 feet) and sits atop a tripod that points the beam downward. The beam can be pointed from nadir to as much as 60 degrees off of nadir producing an illuminating spot geometry that can vary from circular (at nadir) to elliptical in shape (off of nadir). The JP Innovations crystal Cr:LiSAF laser parameters are presented in section II. The illuminating laser spot size is variable and can be adjusted by adjusting the separation distance between the lens and the holographic diffuser. The system is adjusted while platform is at the lowest level. The laser spot is adjusted for a particular spot size at a particular distance (elevation) from the laser by adjusting the separation distance (d{sub diffuser}) to predetermined values. The downward pointing angle is also adjusted before the platform is raised to the selected operation elevation.

  14. Neutron activation analysis of some building materials

    NASA Astrophysics Data System (ADS)

    Salagean, M. N.; Pantelica, A. I.; Georgescu, I. I.; Muntean, M. I.

    1999-01-01

    Concentrations of As, Au, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mo, Na, Nd, Rb, Sb, Sc, Sr, Ta, Tb, Th, U. Yb, W and Zn in seven Romanian building materials were determined by the Instrumental Neutron Activation Analysis (INAA) method using the VVR-S Reactor of NIPNE- Bucharest. Raw matarials used in cement obtaining ≈ 75% of limestone and ≈ 25% of clay, cement samples from three different factories, furnace slag, phosphogypsum, and a type of brick have been analyzed. The brick was compacted from furnace slay, fly coal ash, phosphogypsum, lime and cement. The U, Th and K concentrations determined in the brick are in agreement with the natural radioactivity measurements of226Ra,232Th and40K. These specific activities were found about twice and 1.5 higher than the accepted levels in the case of226Ra and232Th, as well as40K, respectively. By consequence, the investigated brick is considered a radioactive waste. The rather high content of Co, Cr, K, Th, and Zh in the brick is especially due to the slag and fly ash, the main componets. The presence of U, Th and K in slag is mainly correlated with the limestone and dolomite as fluxes in matallurgy.

  15. Theoretical study on the adsorption of phenol on activated carbon using density functional theory.

    PubMed

    Cam, Le Minh; Van Khu, Le; Ha, Nguyen Ngoc

    2013-10-01

    Density functional theory (DFT) calculations performed at the PBE/DZP level using the DFT-D2 method were utilized to investigate the adsorption of phenol on pristine activated carbon (AC) and on activated carbon functionalized with OH, CHO, or COOH groups. Over the pristine AC, the phenol molecule undergoes weak physical adsorption due to van der Waals interactions between the aromatic part of the phenol and the basal planes of the AC. Among the three functional groups used to functionalize the AC, the carboxylic group was found to interact most strongly with the hydroxyl group of phenol. These results suggest that functionalized AC-COOH has great potential for use in environmental applications as an adsorbent of phenol molecules in aqueous phases. PMID:23918222

  16. Kinematic matrix theory and universalities in self-propellers and active swimmers.

    PubMed

    Nourhani, Amir; Lammert, Paul E; Borhan, Ali; Crespi, Vincent H

    2014-06-01

    We describe an efficient and parsimonious matrix-based theory for studying the ensemble behavior of self-propellers and active swimmers, such as nanomotors or motile bacteria, that are typically studied by differential-equation-based Langevin or Fokker-Planck formalisms. The kinematic effects for elementary processes of motion are incorporated into a matrix, called the "kinematrix," from which we immediately obtain correlators and the mean and variance of angular and position variables (and thus effective diffusivity) by simple matrix algebra. The kinematrix formalism enables us recast the behaviors of a diverse range of self-propellers into a unified form, revealing universalities in their ensemble behavior in terms of new emergent time scales. Active fluctuations and hydrodynamic interactions can be expressed as an additive composition of separate self-propellers. PMID:25019773

  17. Analysis of Dietz`s single, rectangular pulse theory for the generation of radiation via photoelectrons

    SciTech Connect

    Dipp, T.M.

    1993-12-01

    The generation of radiation via photoelectrons induced off of a conducting surface has been analytically modeled and computationally simulated by several researchers. This paper analyzes and compares Dietz`s theory predictions with my research to form a unified foundation of consistent, inter-supporting results that should provide confidence in the independently performed basic research and resulting scaling laws and predictions. In doing so, this paper concentrated on Dietz`s small-spot, single, rectangular, ``weak`` pulse theory and equations, which involve nonrelativistic, monoenergetic photoelectrons emitted normal to a conducting surface in vacuum. In this paper I: (1) analytically compare Dietz`s theory equations with my theory equations, (2) compare Dietz`s theoretical scaling laws with my Particle-In-Cell (PIC) code simulation results, and (3) make Dietz`s equations easier to use in predicting and optimizing photoelectron-generated radiation. As a result, it is shown that Dietz`s equations match my theory`s equations in their predicted scaling laws, differing only slightly in their coefficients and unique model parameters. Also, Dietz`s equations generally agree with the PIC code results. Finally, optimization analysis showed that theoretical conversion efficiencies for typical real metals can meet and exceed values of 10{sup {minus}5} if optimal photon energies of 15 to 20 eV are used. Even better efficiencies should be possible if the small-spot constraint is violated as well.

  18. Evidence, Theory and Context: Using intervention mapping to develop a worksite physical activity intervention

    PubMed Central

    McEachan, Rosemary RC; Lawton, Rebecca J; Jackson, Cath; Conner, Mark; Lunt, Jennifer

    2008-01-01

    Background The workplace is an ideal setting for health promotion. Helping employees to be more physically active can not only improve their physical and mental health, but can also have economic benefits such as reduced sickness absence. The current paper describes the development of a three month theory-based intervention that aims to increase levels of moderate intensity physical activity amongst employees in sedentary occupations. Methods The intervention was developed using an intervention mapping protocol. The intervention was also informed by previous literature, qualitative focus groups, an expert steering group, and feedback from key contacts within a range of organisations. Results The intervention was designed to target awareness (e.g. provision of information), motivation (e.g. goal setting, social support) and environment (e.g. management support) and to address behavioural (e.g. increasing moderate physical activity in work) and interpersonal outcomes (e.g. encourage colleagues to be more physically active). The intervention can be implemented by local facilitators without the requirement for a large investment of resources. A facilitator manual was developed which listed step by step instructions on how to implement each component along with a suggested timetable. Conclusion Although time consuming, intervention mapping was found to be a useful tool for developing a theory based intervention. The length of this process has implications for the way in which funding bodies allow for the development of interventions as part of their funding policy. The intervention will be evaluated in a cluster randomised trial involving 1350 employees from 5 different organisations, results available September 2009. PMID:18808709

  19. COMPARISON OF FIVE HEALTH-RELATED QUALITY-OF-LIFE INDEXES USING ITEM RESPONSE THEORY ANALYSIS

    PubMed Central

    Fryback, Dennis G.; Palta, Mari; Cherepanov, Dasha; Bolt, Daniel; Kim, Jee-Seon

    2009-01-01

    Background Five health-related quality-of-life (HRQoL) indexes—EQ-5D, HUI2, HUI3, QWB-SA, and SF-6D—are each used to assign community-based utility scores to health states, although these scores differ. Objective The authors transform these indexes to a common scale to understand their interrelationships. Methods Data were from the National Health Measurement Study, a telephone survey of 3844 US adults. The 5 indexes were analyzed using item response theory analysis to estimate scores on an underlying construct of summary health, θ. Unidimensionality was evaluated using nonlinear principal components analysis. Index scores were plotted against the estimated scores on the common underlying construct. In addition, scores on the Health and Activities Limitation Index (HALex), the Centers for Disease Control and Prevention Healthy Days questions, and self-rated health on a 5-category scale ranging from excellent to poor were plotted. Results SF-6D and QWB-SA are nearly linear across the range of θ, but with a shallow slope; EQ-5D, HUI2, and HUI3 are linear with steep slope from low θ (poor health) into mid-range of θ, then approximately linear with a less steep slope for higher θ (health just below to well above average) although the inflection points differ by index. Conclusion Simple linear functions may serve as crosswalks among these indexes only for lower health states albeit with low precision. Ceiling effects make crosswalks among most of the indexes ill specified above a certain level of health. Although each index measures generic health on a utility scale, these indexes are not identical but are relatively simply, if imprecisely, related. PMID:19843961

  20. Free vibration analysis of a circular cylindrical shell using the Rayleigh-Ritz method and comparison of different shell theories

    NASA Astrophysics Data System (ADS)

    Lee, HyunWook; Kwak, Moon K.

    2015-09-01

    This study uses the Rayleigh-Ritz method to derive a dynamic model for the free vibration analysis of a circular cylindrical shell. In particular, explicit expressions for the mass and stiffness matrices are obtained to easily implement a computer simulation under different shell theories and boundary conditions. The dynamic model is constructed according to the Donnell-Mushtari theory, which is fully discussed herein, and then, dynamic models are constructed by using Sanders theory, Love-Timoshenko theory, Reissner theory, Flügge theory, and Vlasov theory. This paper also discusses the use of eigenfunctions of a uniform beam as admissible functions that produce compact expressions for the mass and stiffness matrices. The numerical results indicate that the Donnell-Mushtari theory is not sufficiently accurate to calculate the natural frequencies and that there is no discernible difference between the other shell theories considered in this study.

  1. Applications of activation analysis to geochemical, meteoritic and lunar studies.

    NASA Technical Reports Server (NTRS)

    Showalter, D. L.; Schmitt, R. A.

    1972-01-01

    The application of activation analysis techniques to the analysis of cosmological materials, i.e., terrestrial, tektitic, meteoritic, and lunar matter, is reviewed. Elemental determinations can be made by instrumental fast-neutron and thermal-neutron activation analysis, photonuclear and charged-particle activation analysis, and by radiochemical neutron activation analysis. Partition-coefficient methods, autoradiography studies, gamma-gamma coincidence counting, and age determination by neutron activation are discussed. Attention is given to K-Ar and I-Xe dating of meteorites.

  2. Analysis of Online Social Networks to Understand Information Sharing Behaviors Through Social Cognitive Theory

    SciTech Connect

    Yoon, Hong-Jun; Tourassi, Georgia

    2014-01-01

    Analyzing the contents of online social networks is an effective process for monitoring and understanding peoples behaviors. Since the nature of conversation and information propagation is similar to traditional conversation and learning, one of the popular socio-cognitive methods, social cognitive theory was applied to online social networks to. Two major news topics about colon cancer were chosen to monitor traffic of Twitter messages. The activity of leaders on the issue (i.e., news companies or people will prior Twitter activity on topics related to colon cancer) was monitored. In addition, the activity of followers , people who never discussed the topics before, but replied to the discussions was also monitored. Topics that produce tangible benefits such as positive outcomes from appropriate preventive actions received dramatically more attention and online social media traffic. Such characteristics can be explained with social cognitive theory and thus present opportunities for effective health campaigns.

  3. The Hamiltonian analysis for Yang-Mills theory on R×S

    NASA Astrophysics Data System (ADS)

    Agarwal, Abhishek; Nair, V. P.

    2009-07-01

    Pure Yang-Mills theory on R×S is analyzed in a gauge-invariant Hamiltonian formalism. Using a suitable coordinatization for the sphere and a gauge-invariant matrix parametrization for the gauge potentials, we develop the Hamiltonian formalism in a manner that closely parallels previous analysis on R. The volume measure on the physical configuration space of the gauge theory, the nonperturbative mass-gap and the leading term of the vacuum wave functional are discussed using a point-splitting regularization. All the results carry over smoothly to known results on R in the limit in which the sphere is de-compactified to a plane.

  4. The concept of sign in the work of Vygotsky, Winnicott and Bakhtin: further integration of object relations theory and activity theory.

    PubMed

    Leiman, M

    1992-09-01

    In a recent paper Ryle introduced the idea of integrating object relations theory and activity theory, a conceptual tradition originated by Vygotsky and developed by a number of Soviet psychologists during the previous decades. A specific aspect of this integrative perspective will be examined, implied in Ryle's paper but not elaborated by him. It is the issue of sign mediation which was Vygotsky's primary contribution to the methodological problems of modern psychology. The aim is to show that object relations theory, especially the work of Winnicott, may bring fresh understanding into Vygotsky's early notions. It is further claimed that, by introducing the contribution of Mikhail Bakhtin and his circle to the notion of sign mediation, the profundity in Winnicott's understanding of the transitional object and of the potential space may be more fully appreciated. At the same time the ideas of Winnicott and Bakhtin will jointly clarify the limitations in Vygotsky's sign conception. PMID:1390355

  5. Using Activity Theory to Understand Learning Design Requirements of Patient Self-Management Environments

    ERIC Educational Resources Information Center

    Schaffer, Scott P.; Reyes, Lisette; Kim, Hannah; Collins, Bart

    2010-01-01

    Learning designs aimed at supporting transformational change could significantly benefit from the adoption of socio-historical and socio-cultural analysis approaches. Such systemic perspectives are gaining more importance in education as they facilitate understanding of complex interactions between learning environments and human activity. The…

  6. Evaluation of a school-based intervention programme to promote physical activity: an application of the theory of planned behavior.

    PubMed

    Tsorbatzoudis, Haralambos

    2005-12-01

    The Theory of Planned Behavior provides a useful framework to study attitudes toward participation in physical activity. The objective of the study was to test the effectiveness of an intervention in manipulating the variables of the Theory of Planned Behavior and exercise habits with 366 high school students (M = 14.2 yr., SD = .7; 201 boys and 165 girls). The students were divided into intervention and control groups. A questionnaire to measure components of the theory, and the Baecke Questionnaire of Habitual Activity measuring exercise habits, were administered. The intervention lasted 12 wk. and included posters and lectures promoting participation in physical activity. Analyses showed the intervention was effective in improving attitudes towards physical activity, perceived behavioral control, intention, and self-reported actual behavior, but it was ineffective for improving attitude strength, subjective norms, and role identity. The results provide useful information for physical education teachers interested in promoting students' positive attitudes towards physical activity. PMID:16491680

  7. A systematic investigation of acetylene activation and hydracyanation of the activated acetylene on Aun (n = 3-10) clusters via density functional theory.

    PubMed

    Gautam, Seema; Sarkar, Abir De

    2016-05-18

    A systematic investigation of the selective catalytic conversion of poisonous HCN gas through hydracyanation of C2H2 activated on Au clusters, presented here for the first time, is of paramount importance from both scientific and technological perspectives. Hydracyanation of activated acetylene on an Au-cluster based catalyst leads to vinyl isocyanide (H2C[double bond, length as m-dash]CHNC) formation, a versatile chemical intermediate. Using density functional theory, bond activation of acetylene and selective catalytic hydracyanation of activated acetylene on small gold clusters Aun (n = 3-10) have been studied through a detailed analysis of the geometric and electronic structures. Different possible complexes of Aun-CHCH have been studied and two possible modes of adsorption of acetylene over the gold clusters, namely, the π- and di-σ modes, have been observed. The hydracyanation of the acetylene molecule is found to occur via the cleavage of one of acetylene triple bonds at the cost of formation of two Au-C bonds followed by the binding of HCN to the activated C[double bond, length as m-dash]C bond via nitrogen's lone pair. Preferential binding sites for HCN and C2H2 are analyzed through Fukui function calculations, frontier molecular orbital analysis and natural population charge distribution analysis. Based on adsorption energies, odd-sized Aun clusters are found to be significantly more favorable for C2H2 adsorption with the C-C bond stretching up to 1.31 Å with respect to the C-C triple bond length of 1.21 Å in the gas phase. The stretching frequency of adsorbed complexes, C2H2/Aun, (3460 cm(-1)), decreases notably relative to the frequency of the free acetylene molecule (7948 cm(-1)), which is a signature of the bond activation of the acetylene molecule over the Au clusters. The high adsorption energy of HCN on the Au9-C2H2 complex implies the considerable binding strength and activation of C2H2 and HCN on the Au9 clusters. Due to the importance of

  8. The (kinetic) theory of active particles applied to learning dynamics. Comment on "Collective learning modeling based on the kinetic theory of active particles" by D. Burini et al.

    NASA Astrophysics Data System (ADS)

    Nieto, J.

    2016-03-01

    The learning phenomena, their complexity, concepts, structure, suitable theories and models, have been extensively treated in the mathematical literature in the last century, and [4] contains a very good introduction to the literature describing the many approaches and lines of research developed about them. Two main schools have to be pointed out [5] in order to understand the two -not exclusive- kinds of existing models: the stimulus sampling models and the stochastic learning models. Also [6] should be mentioned as a survey where two methods of learning are pointed out, the cognitive and the social, and where the knowledge looks like a mathematical unknown. Finally, as the authors do, we refer to the works [9,10], where the concept of population thinking was introduced and which motivate the game theory rules as a tool (both included in [4] to develop their theory) and [7], where the ideas of developing a mathematical kinetic theory of perception and learning were proposed.

  9. Feasibility of combining linear theory and impact theory methods for the analysis and design of high speed configurations

    NASA Technical Reports Server (NTRS)

    Brooke, D.; Vondrasek, D. V.

    1978-01-01

    The aerodynamic influence coefficients calculated using an existing linear theory program were used to modify the pressures calculated using impact theory. Application of the combined approach to several wing-alone configurations shows that the combined approach gives improved predictions of the local pressure and loadings over either linear theory alone or impact theory alone. The approach not only removes most of the short-comings of the individual methods, as applied in the Mach 4 to 8 range, but also provides the basis for an inverse design procedure applicable to high speed configurations.

  10. Plant canopy gap-size analysis theory for improving optical measurements of leaf-area index

    NASA Astrophysics Data System (ADS)

    Chen, Jing M.; Cihlar, Josef

    1995-09-01

    Optical instruments currently available for measuring the leaf-area index (LAI) of a plant canopy all utilize only the canopy gap-fraction information. These instruments include the Li-Cor LAI-2000 Plant Canopy Analyzer, Decagon, and Demon. The advantages of utilizing both the canopy gap-fraction and gap-size information are shown. For the purpose of measuring the canopy gap size, a prototype sunfleck-LAI instrument named Tracing Radiation and Architecture of Canopies (TRAC), has been developed and tested in two pure conifer plantations, red pine (Pinus resinosa Ait.) and jack pine (Pinus banksiana Lamb). A new gap-size-analysis theory is presented to quantify the effect of canopy architecture on optical measurements of LAI based on the gap-fraction principle. The theory is an improvement on that of Lang and Xiang [Agric. For. Meteorol. 37, 229 (1986)]. In principle, this theory can be used for any heterogeneous canopies.

  11. Thermoelastic bending analysis of laminated composite plates according to various shear deformation theories

    NASA Astrophysics Data System (ADS)

    Sayyad, Atteshamuddin Shamshuddin; Shinde, Bharati Machhindra; Ghugal, Yuwaraj Marotrao

    2014-11-01

    This study presents the thermoelastic analysis of laminated composite plates subjected to sinusoidal thermal load linearly varying across the thickness. Analytical solutions for thermal displacements and stresses are investigated by using a unified plate theory which includes different functions in terms of thickness coordinate to represent the effect of shear deformation. The theory presented is variationally consistent, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface conditions. Governing equations of equilibrium and associated boundary conditions of the theory are obtained using the principle of virtual work. The Navier solution for simply supported laminated composite plates has been developed. Numerical results are presented to demonstrate the thermal response of the laminated composite plates.

  12. Analysis and synthesis of phase shifting algorithms based on linear systems theory

    NASA Astrophysics Data System (ADS)

    Servin, M.; Estrada, J. C.

    2012-08-01

    We review and update a recently published formalism for the theory of linear Phase Shifting Algorithms (PSAs) based on linear filtering (systems) theory, mainly using the Frequency Transfer Function (FTF). The FTF has been for decades the standard tool in Electrical Engineering to analyze and synthesize their linear systems. Given the well defined FTF approach (matured over the last century), it clarifies, in our view, many not fully understood properties of PSAs. We present easy formulae for the spectra of the PSAs (the FTF magnitude), their Signal to Noise (S/N) power-ratio gain, their detuning robustness, and their harmonic rejection in terms of the FTF. This paper has more practical appeal than previous publications by the same authors, hoping to enrich the understanding of this PSA's theory as applied to the analysis and synthesis of temporal interferometry algorithms in Optical Metrology.

  13. Scaling theory of the process zone of quasibrittle materials: an avalanche crossover analysis

    NASA Astrophysics Data System (ADS)

    Kent-Dobias, Jaron; Shekhawat, Ashivni; Sethna, James

    We present progress towards a natural theory of the process zone surrounding cracks in quasibrittle materials using renormalization group methods. Quasibrittle or disordered brittle materials like concrete evade usual fracture analysis because of strong finite-size effects and a large disordered process zone. Unlike metals, where the process zone is relatively small and dominated by plasticity, microcracking relieves stress around the tip of quasibrittle cracks, a process that is not well understood. Recently, a scaling crossover theory was developed by Sethna and Shekhawat to explain the influence of finite size on the fracture mechanism and avalanche precursors. We extend this theory to model the scaling of stress and distribution of microcracking in the process zone.

  14. Reliability analysis of the objective structured clinical examination using generalizability theory

    PubMed Central

    Trejo-Mejía, Juan Andrés; Sánchez-Mendiola, Melchor; Méndez-Ramírez, Ignacio; Martínez-González, Adrián

    2016-01-01

    Background The objective structured clinical examination (OSCE) is a widely used method for assessing clinical competence in health sciences education. Studies using this method have shown evidence of validity and reliability. There are no published studies of OSCE reliability measurement with generalizability theory (G-theory) in Latin America. The aims of this study were to assess the reliability of an OSCE in medical students using G-theory and explore its usefulness for quality improvement. Methods An observational cross-sectional study was conducted at National Autonomous University of Mexico (UNAM) Faculty of Medicine in Mexico City. A total of 278 fifth-year medical students were assessed with an 18-station OSCE in a summative end-of-career final examination. There were four exam versions. G-theory with a crossover random effects design was used to identify the main sources of variance. Examiners, standardized patients, and cases were considered as a single facet of analysis. Results The exam was applied to 278 medical students. The OSCE had a generalizability coefficient of 0.93. The major components of variance were stations, students, and residual error. The sites and the versions of the tests had minimum variance. Conclusions Our study achieved a G coefficient similar to that found in other reports, which is acceptable for summative tests. G-theory allows the estimation of the magnitude of multiple sources of error and helps decision makers to determine the number of stations, test versions, and examiners needed to obtain reliable measurements. PMID:27543188

  15. Can the theory of planned behaviour predict the physical activity behaviour of individuals?

    PubMed

    Hobbs, Nicola; Dixon, Diane; Johnston, Marie; Howie, Kate

    2013-01-01

    The theory of planned behaviour (TPB) can identify cognitions that predict differences in behaviour between individuals. However, it is not clear whether the TPB can predict the behaviour of an individual person. This study employs a series of n-of-1 studies and time series analyses to examine the ability of the TPB to predict physical activity (PA) behaviours of six individuals. Six n-of-1 studies were conducted, in which TPB cognitions and up to three PA behaviours (walking, gym workout and a personally defined PA) were measured twice daily for six weeks. Walking was measured by pedometer step count, gym attendance by self-report with objective validation of gym entry and the personally defined PA behaviour by self-report. Intra-individual variability in TPB cognitions and PA behaviour was observed in all participants. The TPB showed variable predictive utility within individuals and across behaviours. The TPB predicted at least one PA behaviour for five participants but had no predictive utility for one participant. Thus, n-of-1 designs and time series analyses can be used to test theory in an individual. PMID:22943555

  16. Nuclear Energy Gradients for Internally Contracted Complete Active Space Second-Order Perturbation Theory: Multistate Extensions.

    PubMed

    Vlaisavljevich, Bess; Shiozaki, Toru

    2016-08-01

    We report the development of the theory and computer program for analytical nuclear energy gradients for (extended) multistate complete active space perturbation theory (CASPT2) with full internal contraction. The vertical shifts are also considered in this work. This is an extension of the fully internally contracted CASPT2 nuclear gradient program recently developed for a state-specific variant by us [MacLeod and Shiozaki, J. Chem. Phys. 2015, 142, 051103]; in this extension, the so-called λ equation is solved to account for the variation of the multistate CASPT2 energies with respect to the change in the amplitudes obtained in the preceding state-specific CASPT2 calculations, and the Z vector equations are modified accordingly. The program is parallelized using the MPI3 remote memory access protocol that allows us to perform efficient one-sided communication. The optimized geometries of the ground and excited states of a copper corrole and benzophenone are presented as numerical examples. The code is publicly available under the GNU General Public License. PMID:27388038

  17. Unified Theory of Activated Relaxation in Cold Liquids over 14 Decades in Time

    NASA Astrophysics Data System (ADS)

    Schweizer, Kenneth; Mirigian, Stephen

    2014-03-01

    We formulate a predictive theory at the level of forces of activated relaxation in thermal liquids that covers in a unified manner the apparent Arrhenius, crossover and deeply supercooled regimes (J.Phys.Chem.Lett.4,3648(2013)). The alpha relaxation event involves coupled cage-scale hopping and a long range cooperative elastic distortion of the surrounding liquid, which results in two inter-related, but distinct, barriers. The strongly temperature and density dependent collective barrier is associated with a growing length scale, the shear modulus and density fluctuations. Thermal liquids are mapped to an effective hard sphere fluid based on matching long wavelength density fluctuation amplitudes. The theory is devoid of fit parameters, has no divergences at finite temperature nor below jamming, and captures the key features of the alpha relaxation time in molecular liquids from picoseconds to hundreds of seconds. The approach is extended to polymer liquids based on the Kuhn length as the key variable. The influence of chain length and backbone stiffness on the glass transition temperature and fragility have been studied where degree of polymerization enters via corrections to asymptotic conformational statistics.

  18. Thermally activated post-glitch response of the neutron star inner crust and core. I. Theory

    SciTech Connect

    Link, Bennett

    2014-07-10

    Pinning of superfluid vortices is predicted to prevail throughout much of a neutron star. Based on the idea of Alpar et al., I develop a description of the coupling between the solid and liquid components of a neutron star through thermally activated vortex slippage, and calculate the response to a spin glitch. The treatment begins with a derivation of the vortex velocity from the vorticity equations of motion. The activation energy for vortex slippage is obtained from a detailed study of the mechanics and energetics of vortex motion. I show that the 'linear creep' regime introduced by Alpar et al. and invoked in fits to post-glitch response is not realized for physically reasonable parameters, a conclusion that strongly constrains the physics of a post-glitch response through thermal activation. Moreover, a regime of 'superweak pinning', crucial to the theory of Alpar et al. and its extensions, is probably precluded by thermal fluctuations. The theory given here has a robust conclusion that can be tested by observations: for a glitch in the spin rate of magnitude Δν, pinning introduces a delay in the post-glitch response time. The delay time is t{sub d} = 7(t{sub sd}/10{sup 4} yr)((Δν/ν)/10{sup –6}) d, where t{sub sd} is the spin-down age; t{sub d} is typically weeks for the Vela pulsar and months in older pulsars, and is independent of the details of vortex pinning. Post-glitch response through thermal activation cannot occur more quickly than this timescale. Quicker components of post-glitch response, as have been observed in some pulsars, notably, the Vela pulsar, cannot be due to thermally activated vortex motion but must represent a different process, such as drag on vortices in regions where there is no pinning. I also derive the mutual friction force for a pinned superfluid at finite temperature for use in other studies of neutron star hydrodynamics.

  19. Activation energies for oxygen reduction on platinum alloys: theory and experiment.

    PubMed

    Anderson, Alfred B; Roques, Jérôme; Mukerjee, Sanjeev; Murthi, Vivek S; Markovic, Nenad M; Stamenkovic, Vojislav

    2005-01-27

    A combined theoretical and experimental analysis of the electrode potential dependencies of activation energies is presented for the first step in oxygen reduction over platinum and platinum alloy catalysts in both polycrystalline and carbon supported form. Tafel data for several of the catalysts are used to predict potential-dependent activation energies for oxygen reduction over the 0.6-0.9 V range in strong and weak acid. Comparisons with the theoretical curve show good agreement above 0.8 V, suggesting a fairly constant preexponential factor. Arrhenius determinations of activation energies over the 0.7-0.9 V range yield little trend for weak acid, possibly because of the larger uncertainties in the Arrhenius fits, but the strong acid results have smaller uncertainties and for them the measured activation energies trend up with potential. PMID:16851081

  20. Energy decomposition analysis based on a block-localized wavefunction and multistate density functional theory

    PubMed Central

    Bao, Peng

    2013-01-01

    An interaction energy decomposition analysis method based on the block-localized wavefunction (BLW-ED) approach is described. The first main feature of the BLW-ED method is that it combines concepts of valence bond and molecular orbital theories such that the intermediate and physically intuitive electron-localized states are variationally optimized by self-consistent field calculations. Furthermore, the block-localization scheme can be used both in wave function theory and in density functional theory, providing a useful tool to gain insights on intermolecular interactions that would otherwise be difficult to obtain using the delocalized Kohn–Sham DFT. These features allow broad applications of the BLW method to energy decomposition (BLW-ED) analysis for intermolecular interactions. In this perspective, we outline theoretical aspects of the BLW-ED method, and illustrate its applications in hydrogen-bonding and π–cation intermolecular interactions as well as metal–carbonyl complexes. Future prospects on the development of a multistate density functional theory (MSDFT) are presented, making use of block-localized electronic states as the basis configurations. PMID:21369567

  1. Testing multi-theory model (MTM) in predicting initiation and sustenance of physical activity behavior among college students

    PubMed Central

    Nahar, Vinayak K.; Sharma, Manoj; Catalano, Hannah Priest; Ickes, Melinda J.; Johnson, Paul; Ford, M. Allison

    2016-01-01

    Background: Most college students do not adequately participate in enough physical activity (PA) to attain health benefits. A theory-based approach is critical in developing effective interventions to promote PA. The purpose of this study was to examine the utility of the newly proposed multi-theory model (MTM) of health behavior change in predicting initiation and sustenance of PA among college students. Methods: Using a cross-sectional design, a valid and reliable survey was administered in October 2015 electronically to students enrolled at a large Southern US University. The internal consistency Cronbach alphas of the subscales were acceptable (0.65-0.92). Only those who did not engage in more than 150 minutes of moderate to vigorous intensity aerobic PA during the past week were included in this study. Results: Of the 495 respondents, 190 met the inclusion criteria of which 141 completed the survey. The majority of participants were females (72.3%) and Caucasians (70.9%). Findings of the confirmatory factor analysis (CFA) confirmed construct validity of subscales (initiation model: χ2 = 253.92 [df = 143], P < 0.001, CFI = 0.91, RMSEA = 0.07, SRMR = 0.07; sustenance model: χ2= 19.40 [df = 22], P < 0.001, CFI = 1.00, RMSEA = 0.00, SRMR = 0.03). Multivariate regression analysis showed that 26% of the variance in the PA initiation was explained by advantages outweighing disadvantages, behavioral confidence, work status, and changes in physical environment. Additionally, 29.7% of the variance in PA sustenance was explained by emotional transformation, practice for change, and changes in social environment. Conclusion: Based on this study’s findings, MTM appears to be a robust theoretical framework for predicting PA behavior change. Future research directions and development of suitable intervention strategies are discussed. PMID:27386419

  2. What should be the roles of conscious States and brain States in theories of mental activity?

    PubMed

    Dulany, Donelson E

    2011-01-01

    Answers to the title's question have been influenced by a history in which an early science of consciousness was rejected by behaviourists on the argument that this entails commitment to ontological dualism and "free will" in the sense of indeterminism. This is, however, a confusion of theoretical assertions with metaphysical assertions. Nevertheless, a legacy within computational and information-processing views of mind rejects or de-emphasises a role for consciousness. This paper sketches a mentalistic metatheory in which conscious states are the sole carriers of symbolic representations, and thus have a central role in the explanation of mental activity and action-while specifying determinism and materialism as useful working assumptions. A mentalistic theory of causal learning, experimentally examined with phenomenal reports, is followed by examination of these questions: Are there common roles for phenomenal reports and brain imaging? Is there defensible evidence for unconscious brain states carrying symbolic representations? Are there interesting dissociations within consciousness? PMID:21694964

  3. Cognitive activation theory of stress (CATS): from fish brains to the Olympics.

    PubMed

    Eriksen, Hege R; Murison, Robert; Pensgaard, Anne Marte; Ursin, Holger

    2005-11-01

    The Cognitive Activation Theory of Stress (CATS) offers formal and systematic definitions of the terms and concepts used in stress research. The stress response depends on acquired expectancies to the outcome of the stimulus and the available responses. The stress response itself is an alarm, an increase in arousal necessary for performance and adequate reactions to challenges. The response is healthy and necessary for survival. Only when sustained over time may potential health risks occur. The basic rules for when stress occurs are the same across cultures and species, from fish to Olympic performance in humans. The important dimensions for health are positive expectancies of outcome (coping), control, and safety, for all individuals in all species. PMID:15964143

  4. Density functional theory study of C₂F₅I synthesis over activated carbon catalyst.

    PubMed

    Hu, Yingjie; Xue, Mengwei; Yang, Guangchen; Pan, Renming

    2015-09-01

    Quantum chemistry calculations based on the density functional theory (DFT) are carried out to investigate the reaction mechanism of C2F5I synthesis catalyzed by activated carbon. The possible adsorption configurations of fluorocarbon intermediates are analyzed carefully. Also, the related transition states and reaction pathway are analyzed. According to calculation, firstly, the dehydrofluorination of C2HF5, as the rate-determining step, is catalyzed by the carboxyl acid groups. Secondly, the tetrafluoroethylidene radicals disproportionate on graphite (001) surface instead of rearrangement or dimerization. Next, the fluorine abstractions between fluorocarbon intermediates over graphite (001) surfaces proceed successfully. Finally, the desorbed pentafluoroethyl abstracts iodine atom from molecular iodine spontaneously to afford C2F5I. In adition, our calculations reveal that the carbon deposit in experiment is caused by the fluorine abstraction from fluoroethinyl. The suggested mechanism corresponds with our calculations and available experiments. PMID:26276012

  5. Pavlov's conceptualization of voluntary movements within the framework of the theory of higher nervous activity.

    PubMed

    Windholz, G

    1998-01-01

    Pavlov became interested in the nature of voluntary movements after receiving Konorski and Miller's letter in 1928 describing their experiments on conditioning of motor movements in dogs. Their paradigmatic experiment involved presenting an indifferent stimulus, followed by passive raising of the dog's leg and then reinforcement. If the same stimulus was provided during a number of trials, the animal lifted its corresponding leg. In 1928 Pavlov asked his students to condition motor movements in his laboratory. Although their findings were equivocal, Pavlov incorporated the so-called voluntary movements into his theory of higher nervous activity. Voluntary movements were responses to external environmental contingencies. On the cortical level, the motor analyzer's cells had both afferent and efferent functions. In Pavlov's view, the motor analyzer's cells established connections with the afferent cells of other sensory analyzers. Pavlov held that motor movements, as responses to external and internal environments, give humans the illusion of voluntary behavior. PMID:9805363

  6. Radiative transfer theory for active remote sensing of a layer of nonspherical particles

    NASA Technical Reports Server (NTRS)

    Tsang, L.; Kong, J. A.; Shin, R. T.

    1984-01-01

    The radiative transfer theory is applied to calculate the scattering by a layer of randomly positioned and oriented nonspherical particles. The scattering amplitude functions of each individual particle are calculated with Waterman's T matrix method, which utilizes vector spherical wave functions for expansion of incident, scattered, and surface fields. The orientation of the particles is described by a probability density function of the Eulerian angles of rotation. A rotation matrix is used to relate the T matrix of the principal frame to that of the natural frame of the particle. The extinction matrix and phase matrix of the radiative transfer equations are expressed in terms of the T matrix elements. The extinction matrix for nonspherical particles is generally nondiagonal. There are only two attenuation rates in a specified direction of propagation. The radiative transfer equations are solved by an iterative method to first order in albedo. Numerical results are illustrated as functions of incidence angle and frequency with applications to active remote sensing.

  7. Activity of rhodium-catalyzed hydroformylation: added insight and predictions from theory.

    PubMed

    Sparta, Manuel; Børve, Knut J; Jensen, Vidar R

    2007-07-11

    We have performed a density functional theory investigation of hydroformylation of ethylene for monosubstituted rhodium-carbonyl catalysts, HRh(CO)3L, where the modifying ligand, L, is a phosphite (L = P(OMe)3, P(OPh)3, or P(OCH2CF3)3), a phosphine (L = PMe3, PEt3, PiPr3, or PPh3), or a N-heterocyclic carbene (NHC) based on the tetrahydropyrimidine, imidazol, or tetrazol ring, respectively. The study follows the Heck and Breslow mechanism. Excellent correspondence between our calculations and existing experimental information is found, and the present results constitute the first example of a realistic quantum chemical description of the catalytic cycle of hydroformylation using ligand-modified rhodium carbonyl catalysts. This description explains the mechanistic and kinetic basis of the contemporary understanding of this class of reaction and offers unprecedented insight into the electronic and steric factors governing catalytic activity. The insight has been turned into structure-activity relationships and used as guidelines when also subjecting to calculation phosphite and NHC complexes that have yet to be reported experimentally. The latter calculations illustrate that it is possible to increase the electron-withdrawing capacity of both phosphite and NHC ligands compared to contemporary ligands through directed substitution. Rhodium complexes of such very electron-withdrawing ligands are predicted to be more active than contemporary catalysts for hydroformylation. PMID:17555314

  8. Parallel robots in a ground-based telescope active optics system: theory and experiments

    NASA Astrophysics Data System (ADS)

    Schipani, P.; Ferragina, L.; Marty, L.; Grado, A.; Di Fiore, L.; De Rosa, R.; La Rana, A.; Busatta, A.

    2007-10-01

    This work deals with the application of parallel robots for the correction of defocus and coma optical aberrations in the case study of the VST (VLT Survey Telescope) telescope, to be installed at the ESO observatory of Cerro Paranal (Chile). The parallel robots are used to change position and orientation of the secondary mirror. The secondary mirror positioning capability is a fundamental part in an active optics system, i.e. a closed loop control system for the minimization of the telescope optical aberrations, where the outer optical feedback coming from the wavefront sensor is used to generate references for the inner motion control loop of the secondary mirror positioning robots. Two devices are presented: a 6-6 Stewart platform where both fixed and mobile platforms are regular and similar hexagons whose vertexes belong to the same plane and are on a circle, and a two stages device composed by a XY table plus a tilt platform. The basic theory of active optics corrections is presented. The kinematics of both devices is solved in connection with the active optics application; first test data are presented.

  9. Activity Theory as a Framework for Investigating District-Classroom System Interactions and Their Influences on Technology Integration

    ERIC Educational Resources Information Center

    Anthony, Anika Ball

    2012-01-01

    Technology implementation research indicates that teachers' beliefs and knowledge, as well as a host of institutional factors, can influence technology integration. Drawing on third-generation activity theory, this article conceptualizes technology implementation as a network of planning and integration activities carried out by technology…

  10. Testing Social-Cognitive Theory to Explain Physical Activity Change in Adolescent Girls from Low-Income Communities

    ERIC Educational Resources Information Center

    Dewar, Deborah L.; Plotnikoff, Ronald C.; Morgan, Philip J.; Okely, Anthony D.; Costigan, Sarah A.; Lubans, David R.

    2013-01-01

    Purpose: The aim of this study was to test the hypothesized structural paths in Bandura's social-cognitive theory (SCT) model on adolescent girls' physical activity following a 12-month physical activity and dietary intervention to prevent obesity. Method: We conducted a 12-month follow-up study of 235 adolescent girls ("M[subscript…

  11. Density Functional Theory Study of Oxygen Reduction Activity on Ultrathin Platinum Nanotubes

    SciTech Connect

    Matanovic, Ivana; Kent, Paul; Garzon, Fernando; Henson, Neil J.

    2012-07-13

    The structure, stability, and catalytic activity of a number of single- and double-wall platinum (n,m) nanotubes ranging in diameter from 0.3 to 2.0 nm were studied using plane-wave based density functional theory in the gas phase and water environment. The change in the catalytic activity toward the oxygen reduction reaction (ORR) with the size and chirality of the nanotube was studied by calculating equilibrium adsorption potentials for ORR intermediates and by constructing free energy diagrams in the ORR dissociative mechanism network. In addition, the stability of the platinum nanotubes is investigated in terms of electrochemical dissolution potentials and by determining the most stable state of the material as a function of pH and potential, as represented in Pourbaix diagrams. Our results show that the catalytic activity and the stability toward electrochemical dissolution depend greatly on the diameter and chirality of the nanotube. On the basis of the estimated overpotentials for ORR, we conclude that smaller, approximately 0.5 nm in diameter single-wall platinum nanotubes consistently show a huge, up to 400 mV larger overpotential than platinum, indicating very poor catalytic activity toward ORR. This is the result of substantial structural changes induced by the adsorption of any chemical species on these tubes. Single-wall n = m platinum nanotubes with a diameter larger than 1 nm have smaller ORR overpotentials than bulk platinum for up to 180 mV and thus show improved catalytic activity relative to bulk. We also predict that these nanotubes can endure the highest cell potentials but dissolution potentials are still for 110 mV lower than for the bulk, indicating a possible corrosion problem.

  12. Lost for emotion words: what motor and limbic brain activity reveals about autism and semantic theory.

    PubMed

    Moseley, Rachel L; Shtyrov, Yury; Mohr, Bettina; Lombardo, Michael V; Baron-Cohen, Simon; Pulvermüller, Friedemann

    2015-01-01

    Autism spectrum conditions (ASC) are characterised by deficits in understanding and expressing emotions and are frequently accompanied by alexithymia, a difficulty in understanding and expressing emotion words. Words are differentially represented in the brain according to their semantic category and these difficulties in ASC predict reduced activation to emotion-related words in limbic structures crucial for affective processing. Semantic theories view 'emotion actions' as critical for learning the semantic relationship between a word and the emotion it describes, such that emotion words typically activate the cortical motor systems involved in expressing emotion actions such as facial expressions. As ASC are also characterised by motor deficits and atypical brain structure and function in these regions, motor structures would also be expected to show reduced activation during emotion-semantic processing. Here we used event-related fMRI to compare passive processing of emotion words in comparison to abstract verbs and animal names in typically-developing controls and individuals with ASC. Relatively reduced brain activation in ASC for emotion words, but not matched control words, was found in motor areas and cingulate cortex specifically. The degree of activation evoked by emotion words in the motor system was also associated with the extent of autistic traits as revealed by the Autism Spectrum Quotient. We suggest that hypoactivation of motor and limbic regions for emotion word processing may underlie difficulties in processing emotional language in ASC. The role that sensorimotor systems and their connections might play in the affective and social-communication difficulties in ASC is discussed. PMID:25278250

  13. Lost for emotion words: What motor and limbic brain activity reveals about autism and semantic theory

    PubMed Central

    Moseley, Rachel L.; Shtyrov, Yury; Mohr, Bettina; Lombardo, Michael V.; Baron-Cohen, Simon; Pulvermüller, Friedemann

    2015-01-01

    Autism spectrum conditions (ASC) are characterised by deficits in understanding and expressing emotions and are frequently accompanied by alexithymia, a difficulty in understanding and expressing emotion words. Words are differentially represented in the brain according to their semantic category and these difficulties in ASC predict reduced activation to emotion-related words in limbic structures crucial for affective processing. Semantic theories view ‘emotion actions’ as critical for learning the semantic relationship between a word and the emotion it describes, such that emotion words typically activate the cortical motor systems involved in expressing emotion actions such as facial expressions. As ASC are also characterised by motor deficits and atypical brain structure and function in these regions, motor structures would also be expected to show reduced activation during emotion-semantic processing. Here we used event-related fMRI to compare passive processing of emotion words in comparison to abstract verbs and animal names in typically-developing controls and individuals with ASC. Relatively reduced brain activation in ASC for emotion words, but not matched control words, was found in motor areas and cingulate cortex specifically. The degree of activation evoked by emotion words in the motor system was also associated with the extent of autistic traits as revealed by the Autism Spectrum Quotient. We suggest that hypoactivation of motor and limbic regions for emotion word processing may underlie difficulties in processing emotional language in ASC. The role that sensorimotor systems and their connections might play in the affective and social-communication difficulties in ASC is discussed. PMID:25278250

  14. Developing a Model of Theory-to-Practice-to-Theory in Student Affairs: An Extended Case Analysis of Theories of Student Learning and Development

    ERIC Educational Resources Information Center

    Kimball, Ezekiel W.

    2012-01-01

    Recent literature suggests a problematic connection between theory and practice in higher education scholarship generally and the study of student learning and development specifically (e.g. Bensimon, 2007; Kezar, 2000; Love, 2012). Much of this disconnect stems from a lack of differentiation between various types of theory used in student affairs…

  15. Active Control of Sound Field Using State-Space Model and Feedback Control Theory: a Numerical Simulation.

    NASA Astrophysics Data System (ADS)

    Wu, Zhen

    Active sound filed control techniques have received growing attention since they provide alternative solutions to low-frequency sound control, where the conventional passive methods have not been very successful. They have wide industrial and military applications such as noise reduction, room acoustics design, acoustic measurements, underwater acoustic camouflage, etc. An appropriate model of an acoustical system serves as the basis of control law synthesis and active control system design. A classical system model describes the dynamics of an acoustic system in a view of input/output relation through transfer functions. On the other hand, a time-domain based state-space model equivalently describes the system dynamics in terms of internal system variables and provides a direct physical insight of active control of sound. Furthermore, based on a state-space model, one can take advantage of modern control analysis and synthesis tools to design an optimal control system for broadband, global sound absorption. This thesis explores state-space feedback control in unbounded acoustic systems. State-space models are developed for unbounded one-dimensional acoustic systems using a finite-difference method with special boundary treatments. State feedback control algorithms including state estimations are developed using optimal control theory (LQG). Numerical simulation results of the closed-loop system responses demonstrate the optimal performance of active control systems considering the trade-off between the high reflection reduction and limited sensing/actuating power. Two numerical examples, an active underwater sound absorbing coating system, and an active noise control system in a duct, are studied. For the active underwater sound absorbing system, a feedback control system involving two sensors and one actuator is designed. Numerical simulation of the closed-loop response indicates a substantial and broadband reflection (echo) reduction for this design. A variety

  16. The Nc dependencies of baryon masses: Analysis with Lattice QCD and Effective Theory

    SciTech Connect

    Calle Cordon, Alvaro C.; DeGrand, Thomas A.; Goity, Jose L.

    2014-07-01

    Baryon masses at varying values of Nc and light quark masses are studied with Lattice QCD and the results are analyzed in a low energy effective theory based on a combined framework of the 1/Nc and Heavy Baryon Chiral Perturbation Theory expansions. Lattice QCD results for Nc=3, 5 and 7 obtained in quenched calculations, as well as results for unquenched calculations for Nc=3, are used for the analysis. The results are consistent with a previous analysis of Nc=3 LQCD results, and in addition permit the determination of sub-leading in 1/Nc effects in the spin-flavor singlet component of the baryon masses as well as in the hyperfine splittings.

  17. ID201202961, DOE S-124,539, Information Security Analysis Using Game Theory and Simulation

    SciTech Connect

    Abercrombie, Robert K; Schlicher, Bob G

    2012-01-01

    Information security analysis can be performed using game theory implemented in dynamic simulations of Agent Based Models (ABMs). Such simulations can be verified with the results from game theory analysis and further used to explore larger scale, real world scenarios involving multiple attackers, defenders, and information assets. Our approach addresses imperfect information and scalability that allows us to also address previous limitations of current stochastic game models. Such models only consider perfect information assuming that the defender is always able to detect attacks; assuming that the state transition probabilities are fixed before the game assuming that the players actions are always synchronous; and that most models are not scalable with the size and complexity of systems under consideration. Our use of ABMs yields results of selected experiments that demonstrate our proposed approach and provides a quantitative measure for realistic information systems and their related security scenarios.

  18. Implementation of Laminate Theory Into Strain Rate Dependent Micromechanics Analysis of Polymer Matrix Composites

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.

    2000-01-01

    A research program is in progress to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to impact loads. Previously, strain rate dependent inelastic constitutive equations developed to model the polymer matrix were implemented into a mechanics of materials based micromechanics method. In the current work, the computation of the effective inelastic strain in the micromechanics model was modified to fully incorporate the Poisson effect. The micromechanics equations were also combined with classical laminate theory to enable the analysis of symmetric multilayered laminates subject to in-plane loading. A quasi-incremental trapezoidal integration method was implemented to integrate the constitutive equations within the laminate theory. Verification studies were conducted using an AS4/PEEK composite using a variety of laminate configurations and strain rates. The predicted results compared well with experimentally obtained values.

  19. Testing Theory of Planned Behavior and Neo-Socioanalytic Theory models of trait activity, industriousness, exercise social cognitions, exercise intentions, and physical activity in a representative U.S. sample

    PubMed Central

    Vo, Phuong T.; Bogg, Tim

    2015-01-01

    Prior research identified assorted relations between trait and social cognition models of personality and engagement in physical activity. Using a representative U.S. sample (N = 957), the goal of the present study was to test two alternative structural models of the relationships among the extraversion-related facet of activity, the conscientiousness-related facet of industriousness, social cognitions from the Theory of Planned Behavior (perceived behavioral control, affective attitudes, subjective norms, intentions), Social Cognitive Theory (self-efficacy, outcome expectancies), and the Transtheoretical Model (behavioral processes of change), and engagement in physical activity. Path analyses with bootstrapping procedures were used to model direct and indirect effects of trait and social cognition constructs on physical activity through two distinct frameworks – the Theory of Planned Behavior and Neo-Socioanalytic Theory. While both models showed good internal fit, comparative model information criteria showed the Theory-of-Planned-Behavior-informed model provided a better fit. In the model, social cognitions fully mediated the relationships from the activity facet and industriousness to intentions for and engagement in physical activity, such that the relationships were primarily maintained by positive affective evaluations, positive expected outcomes, and confidence in overcoming barriers related to physical activity engagement. The resultant model – termed the Disposition-Belief-Motivation model– is proposed as a useful framework for organizing and integrating personality trait facets and social cognitions from various theoretical perspectives to investigate the expression of health-related behaviors, such as physical activity. Moreover, the results are discussed in terms of extending the application of the Disposition-Belief-Motivation model to longitudinal and intervention designs for physical activity engagement. PMID:26300811

  20. Testing Theory of Planned Behavior and Neo-Socioanalytic Theory models of trait activity, industriousness, exercise social cognitions, exercise intentions, and physical activity in a representative U.S. sample.

    PubMed

    Vo, Phuong T; Bogg, Tim

    2015-01-01

    Prior research identified assorted relations between trait and social cognition models of personality and engagement in physical activity. Using a representative U.S. sample (N = 957), the goal of the present study was to test two alternative structural models of the relationships among the extraversion-related facet of activity, the conscientiousness-related facet of industriousness, social cognitions from the Theory of Planned Behavior (perceived behavioral control, affective attitudes, subjective norms, intentions), Social Cognitive Theory (self-efficacy, outcome expectancies), and the Transtheoretical Model (behavioral processes of change), and engagement in physical activity. Path analyses with bootstrapping procedures were used to model direct and indirect effects of trait and social cognition constructs on physical activity through two distinct frameworks - the Theory of Planned Behavior and Neo-Socioanalytic Theory. While both models showed good internal fit, comparative model information criteria showed the Theory-of-Planned-Behavior-informed model provided a better fit. In the model, social cognitions fully mediated the relationships from the activity facet and industriousness to intentions for and engagement in physical activity, such that the relationships were primarily maintained by positive affective evaluations, positive expected outcomes, and confidence in overcoming barriers related to physical activity engagement. The resultant model - termed the Disposition-Belief-Motivation model- is proposed as a useful framework for organizing and integrating personality trait facets and social cognitions from various theoretical perspectives to investigate the expression of health-related behaviors, such as physical activity. Moreover, the results are discussed in terms of extending the application of the Disposition-Belief-Motivation model to longitudinal and intervention designs for physical activity engagement. PMID:26300811

  1. Analysis of Solar Magnetic Activity with the Wavelet Coherence Method

    NASA Astrophysics Data System (ADS)

    Velasco, V. M.; Perez-Peraza, J. A.; Mendoza, B. E.; Valdes-Galicia, J. F.; Sosa, O.; Alvarez-Madrigal, M.

    2007-05-01

    The origin, behavior and evolution of the solar magnetic field is one of the main challenges of observational and theoretical solar physics. Up to now the Dynamo theory gives us the best approach to the problem. However, it is not yet able to predict many features of the solar activity, which seems not to be strictly a periodical phenomenon. Among the indicators of solar magnetic variability there is the 11-years cycle of sunspots, as well as the solar magnetic cycle of 22 years (the Hale cycle). In order to provide more elements to the Dynamo theory that could help it in the predicting task, we analyze here the plausible existence of other periodicities associated with the solar magnetic field. In this preliminary work we use historical data (sunspots and aurora borealis), proxies (Be10 and C14) and modern instrumental data (Coronal Holes, Cosmic Rays, sunspots, flare indexes and solar radio flux at 10.7 cm). To find relationships between different time-frequency series we have employed the t Wavelet Coherence technique: this technique indicates if two time-series of solar activity have the same periodicities in a given time interval. If so, it determines whether such relation is a linear one or not. Such a powerful tool indicates that, if some periodicity at a given frequency has a confidence level below 95%, it appears very lessened or does not appear in the Wavelet Spectral Analysis, such periodicity does not exist . Our results show that the so called Glaisberg cycle of 80-90 years and the periodicity of 205 years (the Suess cycle) do not exist . It can be speculated that such fictitious periodicities hav been the result of using the Fourier transform with series with are not of stationary nature, as it is the case of the Be10 and C14 series. In contrast we confirm the presence of periodicities of 1.3, 1.7, 3.5, 5.5, 7, 60, 120 and 240 years. The concept of a Glaisberg cycle falls between those of 60 and 120 years. We conclude that the periodicity of 120 years

  2. The neurophysiological aspects of Pavlov's theory of higher nervous activity: in honor of the 150th anniversary of Pavlov's birth.

    PubMed

    Grimsley, D L; Windholz, G

    2000-08-01

    Whereas Ivan P. Pavlov (1849-1936) is well-known for his work on classical conditioning, his contribution to neuroscience, particularly his interest in the function of neural centers in the central nervous system, is not as widely known. During the last three decades of his life, Pavlov explored cortical processes by salivary reflex conditioning, a method he used to develop his theory of higher nervous activity. This theory outlined the function of the brain in higher organisms in their interaction with the changing environmental contingencies. As early as 1908, Pavlov outlined a neurophysiological theory as the physiological basis of his theory of higher nervous activity. He maintained that the neural processes of excitation and inhibition irradiate and concentrate among the cortical neural centers. Most of all, he emphasized the plasticity of the cortex in higher organisms' in the Darwinian struggle for existence. PMID:11608939

  3. Active and passive imaging of clothes in the NIR and SWIR regions for reflectivity analysis.

    PubMed

    Grönwall, Christina; Steinvall, Ove; Göhler, Benjamin; Hamoir, Dominique

    2016-07-10

    We perform statistical analysis of data from active and passive imaging sensors in the near infrared (NIR) and short wavelength infrared (SWIR) wavelength bands. The data were obtained from measurements performed on clothing in a field campaign and in the laboratory. We show that reflectivity data from active imaging can be fitted to Gaussian functions, although earlier theory proposes gamma-gamma functions. We analyze the reflectivity data collected during the field campaign and compare that data with data obtained in the laboratory. We focus on the added value of active imaging when combined with passive imaging to distinguish different clothes for friend/foe identification. PMID:27409302

  4. Analysis of polarization properties of shallow metallic gratings by an extended Rayleigh-Fano theory

    NASA Technical Reports Server (NTRS)

    Koike, Masato; Namioka, Takeshi

    1991-01-01

    Rayleigh-Fano theory has been extended for the purpose of calculating the polarization anomaly of a grating having shallow grooves and finite conductivity. Simple analytic formulas are derived for predicting the position and the appearance of the anomalies. Phenomenological explanations are given to the origin of the anomalies. The validity of our analysis is examined by comparing computed degree of polarization with experimental data obtained in the visible region for Al-, Ag-, and Au-coated blazed gratings.

  5. Analysis of Material Interface Discontinuities and Superconvergent Fluxes in Finite Difference Theory

    NASA Astrophysics Data System (ADS)

    MacKinnon, R. J.; Carey, G. F.

    1988-03-01

    An analysis of material interface discontinuities is developed and applied in finite difference theory to determine mathematically rigorous averaging techniques for material properties. This result is compared with other averaging techniques, particularly harmonic averaging, which is often applied in practice. We also develop a class of formulas of high accuracy for post-processing the difference formula to compute derivatives (fluxes, stresses), and conduct supporting numerical studies.

  6. Conformational and Thermodynamic Landscape of GPCR Activation from Theory and Computation.

    PubMed

    Dong, Sijia S; Goddard, William A; Abrol, Ravinder

    2016-06-21

    We present a hybrid computational methodology to predict multiple energetically accessible conformations for G protein-coupled receptors (GPCRs) that might play a role in binding to ligands and different signaling partners. To our knowledge, this method, termed ActiveGEnSeMBLE, enables the first quantitative energy profile for GPCR activation that is consistent with the qualitative profile deduced from experiments. ActiveGEnSeMBLE starts with a systematic coarse grid sampling of helix tilts/rotations (∼13 trillion transmembrane-domain conformations) and selects the conformational landscape based on energy. This profile identifies multiple potential active-state energy wells, with the TM3-TM6 intracellular distance as an approximate activation coordinate. These energy wells are then sampled locally using a finer grid to find locally minimized conformation in each energy well. We validate this strategy using the inactive and active experimental structures of β2 adrenergic receptor (hβ2AR) and M2 muscarinic acetylcholine receptor. Structures of membrane-embedded hβ2AR along its activation coordinate are subjected to molecular-dynamics simulations for relaxation and interaction energy analysis to generate a quantitative energy landscape for hβ2AR activation. This landscape reveals several metastable states along this coordinate, indicating that for hβ2AR, the agonist alone is not enough to stabilize the active state and that the G protein is necessary, consistent with experimental observations. The method's application to somatostatin receptor SSTR5 (no experimental structure available) shows that to predict an active conformation it is better to start from an inactive structure template based on a close homolog than to start from an active template based on a distant homolog. The energy landscape for hSSTR5 activation is consistent with hβ2AR in the role of the G protein. These results demonstrate the utility of the ActiveGEnSeMBLE method for predicting

  7. The general practitioner's role in promoting physical activity to older adults: a review based on program theory.

    PubMed

    Hinrichs, Timo; Brach, Michael

    2012-02-01

    Positive influences of physical activity both on many chronic diseases and on preservation of mobility are well documented. But chronically ill or mobility restricted elderly living in their own homes are difficult to reach for interventions. The general practitioner's (GP) surgery offers one of the few opportunities to give advice for physical activity to those people. We used program theory to sound out knowledge on GP-centered physical activity counseling. The "conceptual theory" (evidence for training effects in old age) and the "implementation theory" (unique position of the GP) were reviewed narratively. The "action theory" (effects of GP counseling) was reviewed systematically. According to program theory, appropriate MeSH (Medical subject headings) concepts were Aged OR Aged, 80 and over (Target group), Physicians, Family OR Primary Health Care (Implementation/Setting), Counseling OR Patient Education as Topic OR Disease Management OR Health promotion (Intervention), Exercise OR Motor Activity OR Physical Fitness OR Sports (Determinants). The resulting six review papers (Pubmed, 2000-2009) were presented using the STARLITE mnemonic. Authors agree, that the GP plays a central role in the promotion of physical activity to elderly people, but there is conflicting evidence concerning counseling effectiveness. Utilizing behavioral change strategies and the collaboration between GPs and specialised professions are recommended and currently under research. PMID:21762090

  8. Shared Decision-Making Models Acknowledging an Interprofessional Approach: A Theory Analysis to Inform Nursing Practice.

    PubMed

    Lewis, Krystina B; Stacey, Dawn; Squires, Janet E; Carroll, Sandra

    2016-01-01

    Patient engagement in collaboration with health professionals is essential to deliver quality health care. A shared decision-making (SDM) approach requires that patients are involved in decisions regarding their health. SDM is expanding from the patient-physician dyad to incorporate an interprofessional perspective. Conceptual models can be used to better understand theoretical underpinnings for application in clinical practice. The aim of this article was to conduct a theory analysis of conceptual models using an interprofessional approach to SDM and discuss each model's relevance to nursing practice. Walker and Avant's theory analysis approach was used. Three conceptual models were eligible. For all models, the decision-making process was considered iterative. The development process was described for 1 model. All models were logical, parsimonious, and generalizable. One was supported by empirical testing. No model described how partnerships are enacted to achieve interprofessional SDM. Also, there was limited articulation as to how nurses' roles and contributions differ from other team members. This theory analysis highlights the need for a model that explains how partnerships among interprofessional team members are enacted to better understand the operationalization of interprofessional SDM. Implications for nursing practice at all system levels are offered and supported by the 3 models. PMID:27024998

  9. Time-dependence of graph theory metrics in functional connectivity analysis.

    PubMed

    Chiang, Sharon; Cassese, Alberto; Guindani, Michele; Vannucci, Marina; Yeh, Hsiang J; Haneef, Zulfi; Stern, John M

    2016-01-15

    Brain graphs provide a useful way to computationally model the network structure of the connectome, and this has led to increasing interest in the use of graph theory to quantitate and investigate the topological characteristics of the healthy brain and brain disorders on the network level. The majority of graph theory investigations of functional connectivity have relied on the assumption of temporal stationarity. However, recent evidence increasingly suggests that functional connectivity fluctuates over the length of the scan. In this study, we investigate the stationarity of brain network topology using a Bayesian hidden Markov model (HMM) approach that estimates the dynamic structure of graph theoretical measures of whole-brain functional connectivity. In addition to extracting the stationary distribution and transition probabilities of commonly employed graph theory measures, we propose two estimators of temporal stationarity: the S-index and N-index. These indexes can be used to quantify different aspects of the temporal stationarity of graph theory measures. We apply the method and proposed estimators to resting-state functional MRI data from healthy controls and patients with temporal lobe epilepsy. Our analysis shows that several graph theory measures, including small-world index, global integration measures, and betweenness centrality, may exhibit greater stationarity over time and therefore be more robust. Additionally, we demonstrate that accounting for subject-level differences in the level of temporal stationarity of network topology may increase discriminatory power in discriminating between disease states. Our results confirm and extend findings from other studies regarding the dynamic nature of functional connectivity, and suggest that using statistical models which explicitly account for the dynamic nature of functional connectivity in graph theory analyses may improve the sensitivity of investigations and consistency across investigations. PMID

  10. Application of Dempster-Shafer theory in dose response outcome analysis.

    PubMed

    Chen, Wenzhou; Cui, Yunfeng; He, Yanyan; Yu, Yan; Galvin, James; Hussaini, Yousuff M; Xiao, Ying

    2012-09-01

    The Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) reviews summarize the currently available three-dimensional dose/volume/outcome data from multi-institutions and numerous articles to update and refine the normal tissue dose/volume tolerance guidelines. As pointed out in the review, the data have limitations and even some inconsistency. However, with the help of new physical and statistical techniques, the information in the review could be updated so that patient care can be continually improved. The purpose of this work is to demonstrate the application of a mathematical theory, the Dempster-Shafer theory, in dose/volume/outcome data analysis. We applied this theory to the original data obtained from published clinical studies describing dose response for radiation pneumonitis. Belief and plausibility concepts were introduced for dose response evaluation. We were also able to consider the uncertainty and inconsistency of the data from these studies with Yager's combination rule, a special methodology of Dempster-Shafer theory, to fuse the data at several specific doses. The values of belief and plausibility functions were obtained at the corresponding doses. Then we applied the Lyman-Kutcher-Burman (LKB) model to fit these values and a belief-plausibility range was obtained. This range could be considered as a probability range to assist physicians and treatment planners in determining acceptable dose-volume constraints. Finally, the parameters obtained from the LKB model fitting were compared with those in Emami and Burman's papers and those from other frequentist statistics methods. We found that Emami and Burman's parameters are within the belief-plausibility range we calculated by the Dempster-Shafer theory. PMID:22892545

  11. Application of Dempster-Shafer theory in dose response outcome analysis

    NASA Astrophysics Data System (ADS)

    Chen, Wenzhou; Cui, Yunfeng; He, Yanyan; Yu, Yan; Galvin, James; Hussaini, Yousuff M.; Xiao, Ying

    2012-09-01

    The Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) reviews summarize the currently available three-dimensional dose/volume/outcome data from multi-institutions and numerous articles to update and refine the normal tissue dose/volume tolerance guidelines. As pointed out in the review, the data have limitations and even some inconsistency. However, with the help of new physical and statistical techniques, the information in the review could be updated so that patient care can be continually improved. The purpose of this work is to demonstrate the application of a mathematical theory, the Dempster-Shafer theory, in dose/volume/outcome data analysis. We applied this theory to the original data obtained from published clinical studies describing dose response for radiation pneumonitis. Belief and plausibility concepts were introduced for dose response evaluation. We were also able to consider the uncertainty and inconsistency of the data from these studies with Yager's combination rule, a special methodology of Dempster-Shafer theory, to fuse the data at several specific doses. The values of belief and plausibility functions were obtained at the corresponding doses. Then we applied the Lyman-Kutcher-Burman (LKB) model to fit these values and a belief-plausibility range was obtained. This range could be considered as a probability range to assist physicians and treatment planners in determining acceptable dose-volume constraints. Finally, the parameters obtained from the LKB model fitting were compared with those in Emami and Burman's papers and those from other frequentist statistics methods. We found that Emami and Burman's parameters are within the belief-plausibility range we calculated by the Dempster-Shafer theory.

  12. An active matter analysis of intracellular Active Transport

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Chen, Kejia; Bae, Sung Chul; Granick, Steve

    2012-02-01

    Tens of thousands of fluorescence-based trajectories at nm resolution have been analyzed, regarding active transport along microtubules in living cells. The following picture emerges. Directed motion to pre-determined locations is certainly an attractive idea, but cannot be pre-programmed as to do so would sacrifice adaptability. The polarity of microtubules is inadequate to identify these directions in cells, and no other mechanism is currently known. We conclude that molecular motors carry cargo through disordered intracellular microtubule networks in a statistical way, with loud cellular ``noise'' both in directionality and speed. Programmed random walks describe how local 1D active transport traverses crowded cellular space efficiently, rapidly, minimizing the energy waste that would result from redundant activity. The mechanism of statistical regulation is not yet understood, however.

  13. Theory of activated penetrant diffusion in viscous fluids and colloidal suspensions.

    PubMed

    Zhang, Rui; Schweizer, Kenneth S

    2015-10-14

    We heuristically formulate a microscopic, force level, self-consistent nonlinear Langevin equation theory for activated barrier hopping and non-hydrodynamic diffusion of a hard sphere penetrant in very dense hard sphere fluid matrices. Penetrant dynamics is controlled by a rich competition between force relaxation due to penetrant self-motion and collective matrix structural (alpha) relaxation. In the absence of penetrant-matrix attraction, three activated dynamical regimes are predicted as a function of penetrant-matrix size ratio which are physically distinguished by penetrant jump distance and the nature of matrix motion required to facilitate its hopping. The penetrant diffusion constant decreases the fastest with size ratio for relatively small penetrants where the matrix effectively acts as a vibrating amorphous solid. Increasing penetrant-matrix attraction strength reduces penetrant diffusivity due to physical bonding. For size ratios approaching unity, a distinct dynamical regime emerges associated with strong slaving of penetrant hopping to matrix structural relaxation. A crossover regime at intermediate penetrant-matrix size ratio connects the two limiting behaviors for hard penetrants, but essentially disappears if there are strong attractions with the matrix. Activated penetrant diffusivity decreases strongly with matrix volume fraction in a manner that intensifies as the size ratio increases. We propose and implement a quasi-universal approach for activated diffusion of a rigid atomic/molecular penetrant in a supercooled liquid based on a mapping between the hard sphere system and thermal liquids. Calculations for specific systems agree reasonably well with experiments over a wide range of temperature, covering more than 10 orders of magnitude of variation of the penetrant diffusion constant. PMID:26472397

  14. Theory of activated penetrant diffusion in viscous fluids and colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Schweizer, Kenneth S.

    2015-10-01

    We heuristically formulate a microscopic, force level, self-consistent nonlinear Langevin equation theory for activated barrier hopping and non-hydrodynamic diffusion of a hard sphere penetrant in very dense hard sphere fluid matrices. Penetrant dynamics is controlled by a rich competition between force relaxation due to penetrant self-motion and collective matrix structural (alpha) relaxation. In the absence of penetrant-matrix attraction, three activated dynamical regimes are predicted as a function of penetrant-matrix size ratio which are physically distinguished by penetrant jump distance and the nature of matrix motion required to facilitate its hopping. The penetrant diffusion constant decreases the fastest with size ratio for relatively small penetrants where the matrix effectively acts as a vibrating amorphous solid. Increasing penetrant-matrix attraction strength reduces penetrant diffusivity due to physical bonding. For size ratios approaching unity, a distinct dynamical regime emerges associated with strong slaving of penetrant hopping to matrix structural relaxation. A crossover regime at intermediate penetrant-matrix size ratio connects the two limiting behaviors for hard penetrants, but essentially disappears if there are strong attractions with the matrix. Activated penetrant diffusivity decreases strongly with matrix volume fraction in a manner that intensifies as the size ratio increases. We propose and implement a quasi-universal approach for activated diffusion of a rigid atomic/molecular penetrant in a supercooled liquid based on a mapping between the hard sphere system and thermal liquids. Calculations for specific systems agree reasonably well with experiments over a wide range of temperature, covering more than 10 orders of magnitude of variation of the penetrant diffusion constant.

  15. Theory of activated penetrant diffusion in viscous fluids and colloidal suspensions

    SciTech Connect

    Zhang, Rui; Schweizer, Kenneth S.

    2015-10-14

    We heuristically formulate a microscopic, force level, self-consistent nonlinear Langevin equation theory for activated barrier hopping and non-hydrodynamic diffusion of a hard sphere penetrant in very dense hard sphere fluid matrices. Penetrant dynamics is controlled by a rich competition between force relaxation due to penetrant self-motion and collective matrix structural (alpha) relaxation. In the absence of penetrant-matrix attraction, three activated dynamical regimes are predicted as a function of penetrant-matrix size ratio which are physically distinguished by penetrant jump distance and the nature of matrix motion required to facilitate its hopping. The penetrant diffusion constant decreases the fastest with size ratio for relatively small penetrants where the matrix effectively acts as a vibrating amorphous solid. Increasing penetrant-matrix attraction strength reduces penetrant diffusivity due to physical bonding. For size ratios approaching unity, a distinct dynamical regime emerges associated with strong slaving of penetrant hopping to matrix structural relaxation. A crossover regime at intermediate penetrant-matrix size ratio connects the two limiting behaviors for hard penetrants, but essentially disappears if there are strong attractions with the matrix. Activated penetrant diffusivity decreases strongly with matrix volume fraction in a manner that intensifies as the size ratio increases. We propose and implement a quasi-universal approach for activated diffusion of a rigid atomic/molecular penetrant in a supercooled liquid based on a mapping between the hard sphere system and thermal liquids. Calculations for specific systems agree reasonably well with experiments over a wide range of temperature, covering more than 10 orders of magnitude of variation of the penetrant diffusion constant.

  16. Towards a differentiated understanding of active travel behaviour: Using social theory to explore everyday commuting

    PubMed Central

    Guell, C.; Panter, J.; Jones, N.R.; Ogilvie, D.

    2012-01-01

    Fostering physical activity is an established public health priority for the primary prevention of a variety of chronic diseases. One promising population approach is to seek to embed physical activity in everyday lives by promoting walking and cycling to and from work (‘active commuting’) as an alternative to driving. Predominantly quantitative epidemiological studies have investigated travel behaviours, their determinants and how they may be changed towards more active choices. This study aimed to depart from narrow behavioural approaches to travel and investigate the social context of commuting with qualitative social research methods. Within a social practice theory framework, we explored how people describe their commuting experiences and make commuting decisions, and how travel behaviour is embedded in and shaped by commuters' complex social worlds. Forty-nine semi-structured interviews and eighteen photo-elicitation interviews with accompanying field notes were conducted with a subset of the Commuting and Health in Cambridge study cohort, based in the UK. The findings are discussed in terms of three particularly pertinent facets of the commuting experience. Firstly, choice and decisions are shaped by the constantly changing and fluid nature of commuters' social worlds. Secondly, participants express ambiguities in relation to their reasoning, ambitions and identities as commuters. Finally, commuting needs to be understood as an embodied and emotional practice. With this in mind, we suggest that everyday decision-making in commuting requires the tactical negotiation of these complexities. This study can help to explain the limitations of more quantitative and static models and frameworks in predicting travel behaviour and identify future research directions. PMID:22486840

  17. Noncommutative Maxwell-Chern-Simons theory: One-loop dispersion relation analysis

    NASA Astrophysics Data System (ADS)

    Ghasemkhani, M.; Bufalo, R.

    2016-04-01

    In this paper, we study the three-dimensional noncommutative Maxwell-Chern-Simons theory. In the present analysis, a complete account for the gauge field two-point function renormalizability is presented and physical significant quantities are carefully established. The respective form factor expressions from the gauge field self-energy are computed at one-loop order. More importantly, an analysis of the gauge field dispersion relation, in search of possible noncommutative anomalies and infrared finiteness, is performed for three special cases, with particular interest in the highly noncommutative limit.

  18. Analysis of supersonic stall bending flutter in axial-flow compressor by actuator disk theory

    NASA Technical Reports Server (NTRS)

    Adamczyk, J. J.

    1978-01-01

    An analytical model was developed for predicting the onset of supersonic stall bending flutter in axial-flow compressors. The analysis is based on two-dimensional, compressible, unsteady actuator disk theory. It is applied to a rotor blade row by considering a cascade of airfoils. The effects of shock waves and flow separation are included in the model. Calculations show that the model predicts the onset, in an unshrouded rotor, of a bending flutter mode that exhibits many of the characteristics of supersonic stall bending flutter. The validity of the analysis for predicting this flutter mode is demonstrated.

  19. Application of Schwinger perturbation theory in electron diffraction analysis Part II. Bent XY2-type molecules

    NASA Astrophysics Data System (ADS)

    Ermakov, K. V.; Butayev, B. S.; Spiridonov, V. P.

    1991-08-01

    The method of analysis of molecules by electron diffraction in terms of the intramolecular potential function based on Schwinger thermodynamic perturbation theory formulated in Paper I of this series is extended to include bent XY 2-type molecules. A test of the performance of the analytical formulae derived is given by calculating various thermal average moments. These formulae, within the framework of the scheme of anharmonic diffraction analysis developed in Paper I, were applied to reinterpret the intensity data for Tl 20, SnCl 2, SnBr 2 and SnI 2 in conjunction with spectroscopic data.

  20. Cognitive and affective theory of mind share the same local patterns of activity in posterior temporal but not medial prefrontal cortex.

    PubMed

    Corradi-Dell'Acqua, Corrado; Hofstetter, Christoph; Vuilleumier, Patrik

    2014-08-01

    Understanding emotions in others engages specific brain regions in temporal and medial prefrontal cortices. These activations are often attributed to more general cognitive 'mentalizing' functions, associated with theory of mind and also necessary to represent people's non-emotional mental states, such as beliefs or intentions. Here, we directly investigated whether understanding emotional feelings recruit similar or specific brain systems, relative to other non-emotional mental states. We used functional magnetic resonance imaging with multivoxel pattern analysis in 46 volunteers to compare activation patterns in theory-of-mind tasks for emotions, relative to beliefs or somatic states accompanied with pain. We found a striking dissociation between the temporoparietal cortex, that exhibited a remarkable voxel-by-voxel pattern overlap between emotions and beliefs (but not pain), and the dorsomedial prefrontal cortex, that exhibited distinct (and yet nearby) patterns of activity during the judgment of beliefs and emotions in others. Pain judgment was instead associated with activity in the supramarginal gyrus, middle cingulate cortex and middle insular cortex. Our data reveal for the first time a functional dissociation within brain networks sub-serving theory of mind for different mental contents, with a common recruitment for cognitive and affective states in temporal regions, and distinct recruitment in prefrontal areas. PMID:23770622