Science.gov

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. 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.

  12. 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…

  13. Social cognitive theory and physical activity: a systematic review and meta-analysis.

    PubMed

    Young, M D; Plotnikoff, R C; Collins, C E; Callister, R; Morgan, P J

    2014-12-01

    This review investigated three research questions (i) What is the utility of social cognitive theory (SCT) to explain physical activity (PA)?; (ii) Is the effectiveness of SCT moderated by sample or methodological characteristics? and (iii) What is the frequency of significant associations between the core SCT constructs and PA? Ten electronic databases were searched with no date or sample restrictions. Forty-four studies were retrieved containing 55 SCT models of PA. Methodological quality was assessed using a standardized tool. A random-effects meta-analysis revealed that SCT accounted for 31% of the variance in PA. However, methodological quality was mostly poor for these models. Methodological quality and sample age moderated the PA effect size, with increases in both associated with greater variance explained. Although self-efficacy and goals were consistently associated with PA, outcome expectations and socio-structural factors were not. This review determined that SCT is a useful framework to explain PA behaviour. Higher quality models explained more PA variance, but overall methodological quality was poor. As such, high-quality studies examining the utility of SCT to explain PA are warranted.

  14. 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

  15. 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

    2014-11-30

    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.

  16. [Analysis of decompression safety during extravehicular activity of astronauts in the light of probability theory].

    PubMed

    Nikolaev, V P; Katuntsev, V P

    1998-01-01

    Objectives of the study were comparative assessment of the risk of decompression sickness (DCS) in human subjects during shirt-sleeve simulation of extravehicular activity (EVA) following Russian and U.S. protocols, and analysis of causes of the difference between real and simulated EVA decompression safety. To this end, DCS risk during exposure to a sing-step decompression was estimated with an original method. According to the method, DCS incidence is determined by distribution of nucleation efficacy index (z) in the worst body tissues and its critical values (zm) as a function of initial nitrogen tension in these tissues and final ambient pressure post decompression. Gaussian distribution of z values was calculated basing on results of the DCS risk evaluation on the U.S. EVA protocol in an unsuited chamber test with various pre-breath procedures (Conkin et al., 1987). Half-time of nitrogen washout from the worst tissues was presumed to be 480 min. Calculated DCS risk during short-sleeve EVA simulation by the Russian and U.S. protocols with identical physical loading made up 19.2% and 23.4%, respectively. Effects of the working spacesuit pressure, spacesuit rigidity, metabolic rates during operations in EVA space suit, transcutaneous nitrogen exchange in the oxygen atmosphere of space suit, microgravity, analgesics, short compression due to spacesuit leak tests on the eye of EVA are discussed. Data of the study illustrate and advocate for high decompression safety of current Russian and U.S. EVA protocols.

  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. Using Activity Theory to Design Constructivist Online Learning Environments for Higher Order Thinking: A Retrospective Analysis

    ERIC Educational Resources Information Center

    Morrison, Dirk

    2003-01-01

    This paper examined a particular online learning activity, embedded within a computer supported collaborative learning (CSCL) environment incorporated as part of the larger context of participation in a unique national agricultural leadership development program. Process outcomes such as a high level of collaboration and active peer facilitation…

  19. 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…

  20. 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…

  1. 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…

  2. 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

  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.

  4. 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.

  5. 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.…

  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. 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…

  8. 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…

  9. Alcohol-related and alcohol-free activity participation and enjoyment among college students: a behavioral theories of choice analysis.

    PubMed

    Murphy, James G; Barnett, Nancy P; Colby, Suzanne M

    2006-08-01

    College student alcohol abuse remains a significant public health problem, and there is a need for theory-driven and empirically based models to guide prevention efforts. Behavioral theories of choice assume that the decision to consume alcohol is influenced by the relative value of alcohol versus other available activities. In the present study, a sample of college student drinkers (N=108; 56% female, 44% male) who had previously completed a mandatory alcohol intervention completed a measure of alcohol-related and alcohol-free activity participation and enjoyment. The goals of the study were to examine the influence of drinking quantity and contextual variables on activity enjoyment and to identify enjoyable alcohol-free activities that take place on evenings when students might otherwise be drinking. Overall, students found alcohol-related activities more enjoyable than alcohol-free activities, and drinking quantity was positively related to enjoyment. However, alcohol-free activities such as watching movies, going to the theater or museums, going to bars or parties, hanging out with friends, eating at restaurants, and engaging in creative activity were generally as enjoyable as drinking. Alcohol-free activities that included peers or dates were more enjoyable than solitary activities. Men were less likely to engage in alcohol-free activities that included peers and reported less enjoyment related to alcohol-free activities than did women. Further research is required to identify procedures for increasing participation in alcohol-free activities and to determine whether increased alcohol-free activity participation results in decreased alcohol consumption. PMID:16893277

  10. 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

  11. 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,…

  12. 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.

  13. 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.

  14. 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.

  15. Epistasis analysis using information theory.

    PubMed

    Moore, Jason H; Hu, Ting

    2015-01-01

    Here we introduce entropy-based measures derived from information theory for detecting and characterizing epistasis in genetic association studies. We provide a general overview of the methods and highlight some of the modifications that have greatly improved its power for genetic analysis. We end with a few published studies of complex human diseases that have used these measures.

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

    PubMed

    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.

  17. 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.

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

    PubMed

    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. PMID:26071703

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    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.

  20. 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

  1. 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 G.; Topping, David; Stier, Philip

    2016-09-01

    In this study a novel framework for inverse modelling of cloud condensation nuclei (CCN) spectra is developed using Köhler theory. The framework is established by using model-generated synthetic measurements as calibration data for a parametric sensitivity analysis. Assessment of the relative importance of aerosol physicochemical parameters, while accounting for bulk-surface partitioning of surface-active organic species, is carried out over a range of atmospherically relevant supersaturations. By introducing an objective function that provides a scalar metric for diagnosing the deviation of modelled CCN concentrations from synthetic observations, objective function response surfaces are presented as a function of model input parameters. Crucially, for the chosen calibration data, aerosol-CCN spectrum closure is confirmed as a well-posed inverse modelling exercise for a subset of the parameters explored herein. The response surface analysis indicates that the appointment of appropriate calibration data is particularly important. To perform an inverse aerosol-CCN closure analysis and constrain parametric uncertainties, it is shown that a high-resolution CCN spectrum definition of the calibration data is required where single-valued definitions may be expected to fail. Using Köhler theory to model CCN concentrations requires knowledge of many physicochemical parameters, some of which are difficult to measure in situ on the scale of interest and introduce a considerable amount of parametric uncertainty to model predictions. For all partitioning schemes and environments modelled, model output showed significant sensitivity to perturbations in aerosol log-normal parameters describing the accumulation mode, surface tension, organic : inorganic mass ratio, insoluble fraction, and solution ideality. Many response surfaces pertaining to these parameters contain well-defined minima and are therefore good candidates for calibration using a Monte Carlo Markov Chain (MCMC

  2. Dissociated multi-unit activity and local field potentials: a theory inspired analysis of a motor decision task.

    PubMed

    Mattia, Maurizio; Ferraina, Stefano; Del Giudice, Paolo

    2010-09-01

    Local field potentials (LFP) and multi-unit activity (MUA) recorded in vivo are known to convey different information about the underlying neural activity. Here we extend and support the idea that single-electrode LFP-MUA task-related modulations can shed light on the involved large-scale, multi-modular neural dynamics. We first illustrate a theoretical scheme and associated simulation evidence, proposing that in a multi-modular neural architecture local and distributed dynamic properties can be extracted from the local spiking activity of one pool of neurons in the network. From this new perspective, the spectral features of the field potentials reflect the time structure of the ongoing fluctuations of the probed local neuronal pool on a wide frequency range. We then report results obtained recording from the dorsal premotor (PMd) cortex of monkeys performing a countermanding task, in which a reaching movement is performed, unless a visual stop signal is presented. We find that the LFP and MUA spectral components on a wide frequency band (3-2000 Hz) are very differently modulated in time for successful reaching, successful and wrong stop trials, suggesting an interplay of local and distributed components of the underlying neural activity in different periods of the trials and for different behavioural outcomes. Besides, the MUA spectral power is shown to possess a time-dependent structure, which we suggest could help in understanding the successive involvement of different local neuronal populations. Finally, we compare signals recorded from PMd and dorso-lateral prefrontal (PFCd) cortex in the same experiment, and speculate that the comparative time-dependent spectral analysis of LFP and MUA can help reveal patterns of functional connectivity in the brain.

  3. 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…

  4. Activation Theory and Uses and Gratifications Research.

    ERIC Educational Resources Information Center

    Tate, E. D.

    Uses and gratifications research involves a critical appraisal of conceptual and theoretical issues in mass communication and is concerned with what audience members do with the media. Activation theory understands people as active manipulators of their environment. (Activation refers to that level of psychological and physiological excitement an…

  5. Constructivism theory analysis and application to curricula.

    PubMed

    Brandon, Amy F; All, Anita C

    2010-01-01

    Today's nursing programs are struggling to accommodate the changing needs of the health care environment and need to make changes in how students are taught. Using constructivism theory, whereby learning is an active process in which learners construct new ideas or concepts based upon their current or past knowledge, leaders in nursing education can make a paradigm shift toward concept-based curricula. This article presents a summary and analysis of constructivism and an innovative application of its active-learning principles to curriculum development, specifically for the education of nursing students.

  6. 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.

  7. 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

  8. 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

  9. [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

  10. 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…

  11. 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

  12. 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…

  13. 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…

  14. 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.

  15. A Cladistic Analysis of Phenotypic Associations with Haplotypes Inferred from Restriction Endonuclease Mapping. I. Basic Theory and an Analysis of Alcohol Dehydrogenase Activity in Drosophila

    PubMed Central

    Templeton, Alan R.; Boerwinkle, Eric; Sing, Charles F.

    1987-01-01

    Because some genes have been cloned that have a known biochemical or physiological function, genetic variation can be measured in a population at loci that may directly influence a phenotype of interest. With this measured genotype approach, specific alleles or haplotypes in the probed DNA region can be assigned phenotypic effects. In this paper we address several problems encountered in implementing the measured genotype approach with restriction site data. A number of analytical problems arise in part as a consequence of the linkage disequilibrium that is commonly encountered when dealing with small DNA regions: 1) different restriction site polymorphisms are not statistically independent, 2) the sites being measured are not likely to be the direct cause of the associated phenotypic effects, 3) haplotype classes may be phenotypically heterogeneous, and 4) the sites that are most strongly associated with phenotypic effects are not necessarily the most closely linked to the actual genetic cause of the effects. When recombination and gene conversion are rare, the primary cause of linkage disequilibrium is history (mutational origin, genetic drift, hitchhiking, etc.). We deal with historical association directly by producing a cladogram that partially reconstructs the evolutionary history of the present-day haplotype variability. The cladogram defines a nested analysis of variance that simultaneously detects phenotypic effects, localizes the effects within the cladogram, and identifies haplotypes that are potentially heterogeneous in their phenotypic associations. The power of this approach is illustrated by an analysis of the associations between alcohol dehydrogenase (ADH) activity and restriction site variability in a 13-kb fragment surrounding the ADH locus in Drosophila melanogaster. PMID:2822535

  16. Cognitive activation theory of stress (CATS).

    PubMed

    Ursin, Holger; Eriksen, Hege R

    2010-05-01

    The cognitive activation theory of stress (CATS) is based on a long series of experiments on animals and on humans, in the laboratory, and in real life situations. From the common sense coping concept formulated by Seymour Levine; coping is when my "tommy" does not hurt, we have advanced to a systematic theory for what is behind the relaxed and happy coping rat (and cat). We also cover the translational leap to humans, starting with the now classic parachutist study. The bridge is based on formal and symbolic definitions, a theoretical short cut that Levine actually never really accepted. The essential pathophysiological concept is the potential pathological effects of sustained activation, which may occur in the absence of coping (positive response outcome expectancy). We review the current status of CATS in Behavioural Medicine by discussing its potential explanatory power in epidemiology, prevention and treatment of "subjective health complaints".

  17. 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…

  18. 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

  19. 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

  20. The cross-activation theory at 10.

    PubMed

    Hubbard, Edward M; Brang, David; Ramachandran, Vilayanur S

    2011-09-01

    In 2001, Ramachandran and Hubbard introduced the cross-activation model of grapheme-colour synaesthesia. On the occasion of its 10-year anniversary, we review the evidence from experiments that have been conducted to test the model to assess how it has fared. We examine data from behavioural, functional magnetic resonance imaging (fMRI), anatomical studies (diffusion tensor imaging and voxel-based morphometry), and electroencephalography (EEG) and magnetoencephalography (MEG) studies of grapheme-colour synaesthesia. Although much of this evidence has supported the basic cross-activation hypothesis, our growing knowledge of the neural basis of synaesthesia, grapheme, and colour processing has necessitated two specific updates and modifications to the basic model: (1) our original model assumed that binding and parietal cortex functions were normal in synaesthesia; we now recognize that parietal cortex plays a key role in synaesthetic binding, as part of a two-stage model. (2) Based on MEG data we have recently collected demonstrating that synaesthetic responses begin within 140 ms of stimulus presentation, and an updated understanding of the neural mechanisms of reading as hierarchical feature extraction, we present a revised and updated version of the cross-activation model, the cascaded cross-tuning model. We then summarize data demonstrating that the cross-activation model may be extended to account for other forms of synaesthesia and discuss open questions about how learning, development, and cortical plasticity interact with genetic factors to lead to the full range of synaesthetic experiences. Finally, we outline a number of future directions needed to further test the cross-activation theory and to compare it with alternative theories. PMID:21923784

  1. 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.

  2. 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.

  3. 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…

  4. Analysis of nearfield measurements: Theory

    NASA Astrophysics Data System (ADS)

    Larsson, C.

    1995-01-01

    The paper describes high-resolution coherent radar imaging. Some methods for imaging are described together with their advantages, disadvantages and limitations. An algorithm for nearfield to farfield transformation of radar cross section was developed. The goal for this work is to make a detailed analysis of nearfield measurements on Swedish fighter aircraft possible. However, the use methods are valid in all measurements with high-resolution coherent radar. Matlab routines including a graphical user interface have been developed. The routines can be used to analyze radar cross section measurements. They also form an open platform for further development of the methods used for analysis. The paper is aimed at those that plan for, perform or analyze radar cross section measurements.

  5. 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.

  6. 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…

  7. 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.

  8. 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.

  9. 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)

  10. 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…

  11. Protection motivation theory: is this a worthwhile theory for physical activity promotion?

    PubMed

    Plotnikoff, Ronald C; Trinh, Linda

    2010-04-01

    This article reviews the published studies in the physical activity domain, which include novel hypothesis from our laboratory, that have tested Rogers' Protection Motivation Theory. Across the various population groups, the theory's coping appraisal is generally supported; however, there is limited support for the theory's threat components. Implications of these findings are discussed from both theoretical and practical perspectives.

  12. 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…

  13. Activity theory as a framework for analyzing and redesigning work.

    PubMed

    Engeström, Y

    2000-07-01

    Cultural-historical activity theory is a new framework aimed at transcending the dichotomies of micro- and macro-, mental and material, observation and intervention in analysis and redesign of work. The approach distinguishes between short-lived goal-directed actions and durable, object-oriented activity systems. A historically evolving collective activity system, seen in its network relations to other activity systems, is taken as the prime unit of analysis against which scripted strings of goal-directed actions and automatic operations are interpreted. Activity systems are driven by communal motives that are often difficult to articulate for individual participants. Activity systems are in constant movement and internally contradictory. Their systemic contradictions, manifested in disturbances and mundane innovations, offer possibilities for expansive developmental transformations. Such transformations proceed through stepwise cycles of expansive learning which begin with actions of questioning the existing standard practice, then proceed to actions of analyzing its contradictions and modelling a vision for its zone of proximal development, then to actions of examining and implementing the new model in practice. New forms of work organization increasingly require negotiated 'knotworking' across boundaries. Correspondingly, expansive learning increasingly involves horizontal widening of collective expertise by means of debating, negotiating and hybridizing different perspectives and conceptualizations. Findings from a longitudinal intervention study of children's medical care illuminate the theoretical arguments.

  14. Information theory applications for biological sequence analysis.

    PubMed

    Vinga, Susana

    2014-05-01

    Information theory (IT) addresses the analysis of communication systems and has been widely applied in molecular biology. In particular, alignment-free sequence analysis and comparison greatly benefited from concepts derived from IT, such as entropy and mutual information. This review covers several aspects of IT applications, ranging from genome global analysis and comparison, including block-entropy estimation and resolution-free metrics based on iterative maps, to local analysis, comprising the classification of motifs, prediction of transcription factor binding sites and sequence characterization based on linguistic complexity and entropic profiles. IT has also been applied to high-level correlations that combine DNA, RNA or protein features with sequence-independent properties, such as gene mapping and phenotype analysis, and has also provided models based on communication systems theory to describe information transmission channels at the cell level and also during evolutionary processes. While not exhaustive, this review attempts to categorize existing methods and to indicate their relation with broader transversal topics such as genomic signatures, data compression and complexity, time series analysis and phylogenetic classification, providing a resource for future developments in this promising area.

  15. 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…

  16. 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…

  17. 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…

  18. 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.

  19. Disformal gravity theories: A Jordan frame analysis

    NASA Astrophysics Data System (ADS)

    Sakstein, Jeremy; Verner, Sarunas

    2015-12-01

    The Jordan frame action for general disformal theories is presented and studied for the first time, motivated by several unresolved mysteries that arise when working in the Einstein frame. We present the Friedmann equations and, specializing to exponential functions, study the late-time cosmology using both dynamical systems methods and by finding approximate solutions. Our analysis reveals that either the disformal effects are irrelevant or the Universe evolves towards a phantom phase where the equation of state of dark energy is -3 . There is a marginal case where the asymptotic state of the Universe depends on the model parameters and de Sitter solutions can be obtained. Our findings indicate that the metric singularity found using the Einstein frame construction corresponds to phantom behavior in the Jordan frame and we argue that this is the case for general disformal theories.

  20. 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.

  1. 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.

  2. Discourse and Identity in Cultural-Historical Activity Theory: A Response

    ERIC Educational Resources Information Center

    Daniels, Harry

    2007-01-01

    This article provides a response to two of the papers in the collection. In doing so it takes up two issues: the conceptualization and analysis of discourse within Cultural Historical Activity Theory (CHAT) and notions of identity and subject positioning within CHAT. Bernstein [(2000). "Pedagogy, symbolic control and identity: Theory research…

  3. Time-dependent restricted-active-space self-consistent-field theory for laser-driven many-electron dynamics. II. Extended formulation and numerical analysis

    NASA Astrophysics Data System (ADS)

    Miyagi, Haruhide; Madsen, Lars Bojer

    2014-06-01

    The time-dependent restricted-active-space self-consistent-field (TD-RASSCF) method is formulated based on the TD variational principle. The SCF based TD orbitals contributing to the expansion of the wave function are classified into three groups, between which orbital excitations are considered with the RAS scheme. In analogy with the configuration-interaction singles (CIS), singles-and-doubles (CISD), and singles-doubles-and-triples (CISDT) methods in quantum chemistry, the TD-RASSCF-S, -SD, and -SDT methods are introduced as extensions of the TD-RASSCF-doubles (-D) method [Phys. Rev. A 87, 062511 (2013), 10.1103/PhysRevA.87.062511]. Based on an analysis of the numerical cost and test calculations for one-dimensional (1D) models of atomic helium, beryllium, and carbon, it is shown that the TD-RASSCF-S and -D methods are computationally feasible for systems with many electrons and more accurate than the TD Hartree-Fock (TDHF) and TDCIS methods. In addition to the discussion of methodology, an analysis of electron dynamics in the high-order harmonic generation (HHG) process is presented. For the 1D beryllium atom, a state-resolved analysis of the HHG spectrum based on the time-independent HF orbitals shows that while only single-orbital excitations are needed in the region below the cutoff, single- and double-orbital excitations are essential beyond, where accordingly the single-active-electron (SAE) approximation and the TDCIS method break down. On the other hand, the TD-RASSCF-S and -D methods accurately describe the multiorbital excitation processes throughout the entire region of the HHG spectrum. For the 1D carbon atom, our calculations show that multiorbital excitations are essential in the HHG process even below the cutoff. Hence, in this test system a very accurate treatment of electron correlation is required. The TD-RASSCF-S and -D approaches meet this demand, while the SAE approximation and the TDCIS method are inadequate.

  4. 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

  5. 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.

  6. 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…

  7. [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

  8. [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.

  9. 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…

  10. Active cell mechanics: Measurement and theory.

    PubMed

    Ahmed, Wylie W; Fodor, Étienne; Betz, Timo

    2015-11-01

    Living cells are active mechanical systems that are able to generate forces. Their structure and shape are primarily determined by biopolymer filaments and molecular motors that form the cytoskeleton. Active force generation requires constant consumption of energy to maintain the nonequilibrium activity to drive organization and transport processes necessary for their function. To understand this activity it is necessary to develop new approaches to probe the underlying physical processes. Active cell mechanics incorporates active molecular-scale force generation into the traditional framework of mechanics of materials. This review highlights recent experimental and theoretical developments towards understanding active cell mechanics. We focus primarily on intracellular mechanical measurements and theoretical advances utilizing the Langevin framework. These developing approaches allow a quantitative understanding of nonequilibrium mechanical activity in living cells. This article is part of a Special Issue entitled: Mechanobiology.

  11. Perturbative analysis in higher-spin theories

    NASA Astrophysics Data System (ADS)

    Didenko, V. E.; Misuna, N. G.; Vasiliev, M. A.

    2016-07-01

    A new scheme of the perturbative analysis of the nonlinear HS equations is developed giving directly the final result for the successive application of the homotopy integrations which appear in the standard approach. It drastically simplifies the analysis and results from the application of the standard spectral sequence approach to the higherspin covariant derivatives, allowing us in particular to reduce multiple homotopy integrals resulting from the successive application of the homotopy trick to a single integral. Efficiency of the proposed method is illustrated by various examples. In particular, it is shown how the Central on-shell theorem of the free theory immediately results from the nonlinear HS field equations with no intermediate computations.

  12. 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…

  13. 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

  14. 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)

  15. 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.

  16. [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.

  17. 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'…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. Self-efficacy theory and the theory of planned behavior: teaching physically active physical education classes.

    PubMed

    Martin, Jeffrey J; Kulinna, Pamela Hodges

    2004-09-01

    The purpose of our 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' intentions were determined by subjective norm, attitude, and perceived behavioral control. Grounded in self-efficacy theory, it was hypothesized that program goal importance and hierarchical and barrier self-efficacy would also predict intention. Using a series of hierarchical regression analyses, the theory of planned behavior was supported by accounting for 59% of the variance in intention due to attitude, perceived behavioral control, and subjective norm. Self-efficacy theory based variables received minimal support.

  3. 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…

  4. What propels sexual murderers: a proposed integrated theory of social learning and routine activities theories.

    PubMed

    Chan, Heng Choon Oliver; Heide, Kathleen M; Beauregard, Eric

    2011-04-01

    Despite the great interest in the study of sexual homicide, little is known about the processes involved in an individual's becoming motivated to sexually kill, deciding to sexually kill, and acting on that desire, intention, and opportunity. To date, no comprehensive model of sexual murdering from the offending perspective has been proposed in the criminological literature. This article incorporates the works of Akers and Cohen and Felson regarding their social learning theory and routine activities theory, respectively, to construct an integrated conceptual offending framework in sexual homicide. This integrated model produces a stronger and more comprehensive explanation of sexual murder than any single theory currently available.

  5. What propels sexual murderers: a proposed integrated theory of social learning and routine activities theories.

    PubMed

    Chan, Heng Choon Oliver; Heide, Kathleen M; Beauregard, Eric

    2011-04-01

    Despite the great interest in the study of sexual homicide, little is known about the processes involved in an individual's becoming motivated to sexually kill, deciding to sexually kill, and acting on that desire, intention, and opportunity. To date, no comprehensive model of sexual murdering from the offending perspective has been proposed in the criminological literature. This article incorporates the works of Akers and Cohen and Felson regarding their social learning theory and routine activities theory, respectively, to construct an integrated conceptual offending framework in sexual homicide. This integrated model produces a stronger and more comprehensive explanation of sexual murder than any single theory currently available. PMID:20160008

  6. 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…

  7. 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

  8. A Critical Analysis of Transactional Distance Theory

    ERIC Educational Resources Information Center

    Gorsky, Paul; Caspi, Avner

    2005-01-01

    This investigation reviews published empirical studies that attempted to support or to validate transactional distance theory (Moore, 1993). It was found that either data only partially supported the theory or, that if they apparently did so, the studies lacked reliability, construct validity, or both. It was concluded that the basic propositions…

  9. 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

  10. 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

  11. Assessment of factors that predict physical activity among Oklahoma clergy: a theory of planned behavior approach.

    PubMed

    Gwin, Shannon; Taylor, E Laurette; Branscum, Paul; Hofford, Craig

    2013-01-01

    The purpose of this study was to examine predictors of physical activity among clergy members in Oklahoma, using the theory of planned behavior. A 51-item valid and reliable instrument, measuring theory of planned behavior constructs and physical activity, was developed and administered to 141 clergy members. Results indicated that the majority of those surveyed were white (93%), college educated (97%), and overweight or obese (84%). Stepwise multiple regression analysis found that intentions accounted for 13.8% of the variance of physical activity whereas attitudes, subjective norms, and perceived behavioral control accounted for 54.8% of the variance of intention. Implications for intervention development are discussed.

  12. "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…

  13. 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…

  14. Distributed Leadership through the Lens of Activity Theory

    ERIC Educational Resources Information Center

    Yuen, Jeanne Ho Pau; Victor Chen, Der-Thanq; Ng, David

    2016-01-01

    Purpose: Using Activity Theory as an interpretive lens to examine the distribution of leadership, this paper shares a case study on how leadership for an ICT project was distributed in a Singapore school. Method: The case study involved observations of 49 meetings and 34 interviews of leaders and the teachers who were involved in the ICT project.…

  15. 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…

  16. Active and Collaborative Learning in an Undergraduate Sociological Theory Course

    ERIC Educational Resources Information Center

    Pedersen, Daphne E.

    2010-01-01

    In this article, the author describes the use of active and collaborative learning strategies in an undergraduate sociological theory course. A semester-long ethnographic project is the foundation for the course; both individual and group participation contribute to the learning process. Assessment findings indicate that students are able, through…

  17. 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…

  18. Replacement of the Project Manager Reflected Through Activity Theory and Work-System Theory

    NASA Astrophysics Data System (ADS)

    Vartiainen, Tero; Aramo-Immonen, Heli; Jussila, Jari; Pirhonen, Maritta; Liikamaa, Kirsi

    Replacement of the project manager (RPM) is a known phenomenon in information systems (IS) projects, but scant attention is given to it in the project management or IS literature. Given its critical effects on the project business, the organization, the project team, and the project manager, it should be studied in more depth. We identified factors which make RPM occurrences inherently different and we show that work-system theory and activity theory give comprehensive lenses to advance research on RPM. For the future research on RPM we identified three objectives: experiences on RPM, process model for RPM, and organizational culture's influence on RPM occurrences.

  19. Freudian Theory and Consciousness: A Conceptual Analysis**

    PubMed Central

    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

  20. 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.

  1. 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

  2. Mean-deviation analysis in the theory of choice.

    PubMed

    Grechuk, Bogdan; Molyboha, Anton; Zabarankin, Michael

    2012-08-01

    Mean-deviation analysis, along with the existing theories of coherent risk measures and dual utility, is examined in the context of the theory of choice under uncertainty, which studies rational preference relations for random outcomes based on different sets of axioms such as transitivity, monotonicity, continuity, etc. An axiomatic foundation of the theory of coherent risk measures is obtained as a relaxation of the axioms of the dual utility theory, and a further relaxation of the axioms are shown to lead to the mean-deviation analysis. Paradoxes arising from the sets of axioms corresponding to these theories and their possible resolutions are discussed, and application of the mean-deviation analysis to optimal risk sharing and portfolio selection in the context of rational choice is considered.

  3. 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…

  4. Contingency Analysis: Toward a Unified Theory for Social Work Practice.

    ERIC Educational Resources Information Center

    Thyer, Bruce A.

    1987-01-01

    Draws from the empirical foundations of operant psychology to propose a unified theory, known as contingency analysis, for social work practice. Discusses the four propositions on which the theory is based that account for human behavior at all levels of social work practice. Shows that this approach has great utility for the profession.…

  5. Classical Nucleation Theory Description of Active Colloid Assembly

    NASA Astrophysics Data System (ADS)

    Redner, Gabriel S.; Wagner, Caleb G.; Baskaran, Aparna; Hagan, Michael F.

    2016-09-01

    Nonaligning self-propelled particles with purely repulsive excluded volume interactions undergo athermal motility-induced phase separation into a dilute gas and a dense cluster phase. Here, we use enhanced sampling computational methods and analytic theory to examine the kinetics of formation of the dense phase. Despite the intrinsically nonequilibrium nature of the phase transition, we show that the kinetics can be described using an approach analogous to equilibrium classical nucleation theory, governed by an effective free energy of cluster formation with identifiable bulk and surface terms. The theory captures the location of the binodal, nucleation rates as a function of supersaturation, and the cluster size distributions below the binodal, while discrepancies in the metastable region reveal additional physics about the early stages of active crystal formation. The success of the theory shows that a framework similar to equilibrium thermodynamics can be obtained directly from the microdynamics of an active system, and can be used to describe the kinetics of evolution toward nonequilibrium steady states.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. Theory of partial agonist activity of steroid hormones

    PubMed Central

    Chow, Carson C.; Ong, Karen M.; Kagan, Benjamin; Simons, S. Stoney

    2015-01-01

    The different amounts of residual partial agonist activity (PAA) of antisteroids under assorted conditions have long been useful in clinical applications but remain largely unexplained. Not only does a given antagonist often afford unequal induction for multiple genes in the same cell but also the activity of the same antisteroid with the same gene changes with variations in concentration of numerous cofactors. Using glucocorticoid receptors as a model system, we have recently succeeded in constructing from first principles a theory that accurately describes how cofactors can modulate the ability of agonist steroids to regulate both gene induction and gene repression. We now extend this framework to the actions of antisteroids in gene induction. The theory shows why changes in PAA cannot be explained simply by differences in ligand affinity for receptor and requires action at a second step or site in the overall sequence of reactions. The theory also provides a method for locating the position of this second site, relative to a concentration limited step (CLS), which is a previously identified step in glucocorticoid-regulated transactivation that always occurs at the same position in the overall sequence of events of gene induction. Finally, the theory predicts that classes of antagonist ligands may be grouped on the basis of their maximal PAA with excess added cofactor and that the members of each class differ by how they act at the same step in the overall gene induction process. Thus, this theory now makes it possible to predict how different cofactors modulate antisteroid PAA, which should be invaluable in developing more selective antagonists. PMID:25984562

  11. Self-conception and life satisfaction: integrating aged subculture and activity theory.

    PubMed

    McClelland, K A

    1982-11-01

    This study seeks to expand the traditional activity theory explanation of adjustment to aging by integrating it with the aged subculture theory advanced by Rose. A path model is developed that adds self-conception to social activity, social adequacy, and other predictors of life satisfaction. This model is applied, using an analysis of covariance structures approach, to data from two subsamples of older adults from a national Harris survey. As a result of this analysis, self-conception is shown to be an important intervening variable between social activity and life satisfaction, especially for the subsample of older people who prefer to spend time with others their own age. Finally, a symbolic interactionist perspective is suggested for understanding the importance of self-conception in the process of successful aging.

  12. 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.

  13. 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).

  14. Comparative analysis of theories of relativistic photoionization

    NASA Astrophysics Data System (ADS)

    Hafizi, Bahman; Gordon, Daniel; Palastro, John

    2015-11-01

    Laser-plasma experiments routinely rely on photoionization for plasma formation. For large laser intensities or for high-Z atoms relativistic effects become important. We investigate a unique regime of relativistic photoionization from high-Z atoms where relativistic effects modify both the bound and continuum electronic states. Theories of photoionization are based on the imaginary time method and the S-matrix method, amongst others. We compare the results of these approaches for both the Dirac and the Klein-Gordon equations. Analytical results for the momentum distribution of ejected electrons and ionization rate are presented and compared with those from numerical solutions. Work supported by the Department of Energy and the NRL Base Program.

  15. 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.

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. 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

  1. An Adaptation of Constructive Alternativism as Theory for Audience Analysis.

    ERIC Educational Resources Information Center

    Losee, Doug

    An examination of audience analysis factors in representative communication textbooks indicates that current pedagogical applications are broadly categorized into demographic and dispositional properties. The adaptation of constructivist theory to audience analysis can give speech students reasons why the speaker-audience relationship is as it is.…

  2. 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…

  3. 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…

  4. 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.

  5. Interaction Analysis: Theory, Research and Application.

    ERIC Educational Resources Information Center

    Amidon, Edmund J., Ed.; Hough, John J., Ed.

    This volume of selected readings developed for students and practitioners at various levels of sophistication is intended to be representative of work done to date on interaction analysis. The contents include journal articles, papers read at professional meetings, abstracts of doctoral dissertations, and selections from larger monographs, plus 12…

  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. Static analysis of rectangular nanoplates using trigonometric shear deformation theory based on nonlocal elasticity theory.

    PubMed

    Nami, Mohammad Rahim; Janghorban, Maziar

    2013-12-30

    In this article, a new higher order shear deformation theory based on trigonometric shear deformation theory is developed. In order to consider the size effects, the nonlocal elasticity theory is used. An analytical method is adopted to solve the governing equations for static analysis of simply supported nanoplates. In the present theory, the transverse shear stresses satisfy the traction free boundary conditions of the rectangular plates and these stresses can be calculated from the constitutive equations. The effects of different parameters such as nonlocal parameter and aspect ratio are investigated on both nondimensional deflections and deflection ratios. It may be important to mention that the present formulations are general and can be used for isotropic, orthotropic and anisotropic nanoplates.

  8. [Qualitative analysis: theory, steps and reliability].

    PubMed

    Minayo, Maria Cecília de Souza

    2012-03-01

    This essay seeks to conduct in-depth analysis of qualitative research, based on benchmark authors and the author's own experience. The hypothesis is that in order for an analysis to be considered reliable, it needs to be based on structuring terms of qualitative research, namely the verbs 'comprehend' and 'interpret', and the nouns 'experience', 'common sense' and 'social action'. The 10 steps begin with the construction of the scientific object by its inclusion on the national and international agenda; the development of tools that make the theoretical concepts tangible; conducting field work that involves the researcher empathetically with the participants in the use of various techniques and approaches, making it possible to build relationships, observations and a narrative with perspective. Finally, the author deals with the analysis proper, showing how the object, which has already been studied in all the previous steps, should become a second-order construct, in which the logic of the actors in their diversity and not merely their speech predominates. The final report must be a theoretic, contextual, concise and clear narrative.

  9. A Theory of Hospital Financial Analysis

    PubMed Central

    Elnicki, Richard A.

    1969-01-01

    The problem of determining the financial status of a group of hospitals was posed by the Connecticut Regional Medical Program in 1967 with the question: Are Connecticut's general hospitals financially healthy? The economist assigned to explore the question here describes the economic concepts and the methodology from which models applicable to voluntary hospitals were developed, utilizing the accepted modes of analysis and standards of for-profit business. The basic index of financial health investigated is self-sufficiency, with plant liquidation, revenue control and the role of private payors, and cost control studied as factors affecting the financial status of hospitals. PMID:5799485

  10. 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.

  11. 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.

  12. [Peplau's theory of interpersonal relations: an analysis based of Barnum].

    PubMed

    de Almeida, Vitória de Cássia Félix; Lopes, Marcos Venícios de Oliveira; Damasceno, Marta Maria Coelho

    2005-06-01

    The use of theories in Nursing reflects a movement in the profession towards the autonomy and delimitation of its actions. It is, therefore, extremely relevant that theories may be analyzed as for their applicability to practice. The object of this study is to make an analytical-descriptive study of Peplau's Theory of Interpersonal Relations in Nursing from the model of analysis proposed by Barbara Barnum. Among the structural components that may be analyzed in a theory was chosen the element "process", a method recommended for the development of nursing' actions, which was submitted to Barnum's criteria of usefulness. The assessment showed that Peplau's theoretical presuppositions are operational and may serve as a basis in any situation in which nurses communicate and interact with his/her patients.

  13. 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.

  14. 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

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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.

  20. 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…

  1. The Role of Psychographic Analysis in Developing Mass Communication Theory.

    ERIC Educational Resources Information Center

    Gaziano, Cecilie

    Psychographic analysis--combining demographic and attitudinal characteristics into groups and looking at variations in those characteristics--is useful in newspaper research to expand theories of media publics. One effective segmentation strategy (used at Minnesota Opionion Research Incorporated--MORI) is to divide the population into four groups,…

  2. 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)

  3. 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…

  4. 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.

  5. 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

  6. Water confined in MCM-41: a mode coupling theory analysis

    NASA Astrophysics Data System (ADS)

    Gallo, P.; Rovere, M.; Chen, S.-H.

    2012-02-01

    In this paper we analyze molecular dynamics simulation results on supercooled water in a MCM-41 pore in order to test the mode coupling theory. A layer analysis must be performed for water in the pore in order to exclude the contribution of water bound to the strongly hydrophilic surface. Upon supercooling a range of temperatures is reached where the liquid follows the mode coupling theory. From the power law behavior of the relaxation times extracted from the Kohlrausch-William-Watts fit to the self-intermediate scattering function, we obtain the crossover temperature TC and the γ exponent of the theory. The time-temperature superposition principle is also satisfied. A fit to the von Schweidler law yields a coefficient b from which all the other parameters of the theory have been calculated. In particular, we obtained the same value of γ as extracted from the power law fit to the relaxation times, in agreement with the requirements of the theory. For very low temperatures, the mode coupling theory no longer holds as hopping processes intervene and water turns its behavior to that of a strong liquid.

  7. 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

  8. The benefits of abstract functional analysis in theory construction: the case of interdependence theory.

    PubMed

    Holmes, John G

    2004-01-01

    In this article I argue for the benefits of an abstract functional analysis in theory construction, suggesting that an understanding of the nature of situations of interdependence will provide theoretical insights into basic processes in interpersonal relations. That is, mechanisms and basic processes such as social cognition are best understood by describing their functional relation to the social problems with which they were designed to cope, rather than studying them in their own right in isolation from the purpose they serve. I discuss the tenets of ecological psychology, the scientific philosophy underpinning this way of thought. I then link this approach to the development of my own theoretical ideas on trust in close relationships, providing a description of how a functional analysis rooted in the assumptions of interdependence theory shaped the questions I posed and the answers to which I was drawn. PMID:15223514

  9. Neutron Activation Analysis: Techniques and Applications

    NASA Astrophysics Data System (ADS)

    MacLellan, Ryan

    2011-04-01

    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.

  10. 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.

  11. 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…

  12. 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…

  13. Characterizing active transportation behavior among college students using the theory of planned behavior.

    PubMed

    Chaney, Robert A; Bernard, Amy L; Wilson, Bradley R A

    2013-01-01

    Physical inactivity poses concern for health risks among all groups in the United States. Active transportation (AT) (e.g., bicycling) is one way of being physically active and may be helpful in promoting physical activity. This study characterized active transportation behavior among college students using the Theory of Planned Behavior. This study sought to describe predictors, including Theory of Planned Behavior (TPB) constructs, of AT behavior among college students at a large Midwest university. Students were recruited through the university registrar's office and e-mailed an electronic survey. Differences among AT users were determined using t-tests, and predictors of AT were identified using regression analysis. Significant differences between AT users for all TPB constructs were observed. Regression analysis using only TPB constructs accounted for 11.58% explained variation in AT use. Other variables added to the model resulted in 44.44% explained variation in AT use. The final model included subjective norms, age, perceived behavioral control, and transportation type and destination. The results of this research are insightful in explaining AT behavior. Perceived norms and the level of control students had regarding their method of transportation were important contributions to AT use. These results may be applied to promoting physical activity in community health.

  14. 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.

  15. 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

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

    PubMed

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

    2014-01-13

    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

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

    PubMed

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

    2014-01-13

    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.

  18. 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

  19. 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…

  20. 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.

  1. 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.

  2. 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.

  3. 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. PMID:27239095

  4. Analysis of general power counting rules in effective field theory

    NASA Astrophysics Data System (ADS)

    Gavela, Belen; Jenkins, Elizabeth E.; Manohar, Aneesh V.; Merlo, Luca

    2016-09-01

    We derive the general counting rules for a quantum effective field theory (EFT) in {d} dimensions. The rules are valid for strongly and weakly coupled theories, and they predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. We show that the size of the cross sections is controlled by the Λ power counting of EFT, not by chiral counting, even for chiral perturbation theory (χ PT). The relation between Λ and f is generalized to {d} dimensions. We show that the naive dimensional analysis 4π counting is related to hbar counting. The EFT counting rules are applied to χ PT, low-energy weak interactions, Standard Model EFT and the non-trivial case of Higgs EFT.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. Scattering theory of spin-orbit active adatoms on graphene

    NASA Astrophysics Data System (ADS)

    Pachoud, Alexandre; Ferreira, Aires; Ã-zyilmaz, B.; Castro Neto, A. H.

    2014-07-01

    The scattering of two-dimensional massless Dirac fermions from local spin-orbit interactions with an origin in dilute concentrations of physisorbed atomic species on graphene is theoretically investigated. The hybridization between graphene and the adatoms' orbitals lifts spin and valley degeneracies of the pristine host material, giving rise to rich spin-orbit coupling mechanisms with features determined by the exact adsorption position on the honeycomb lattice—bridge, hollow, or top position—and the adatoms' outer-shell orbital type. Effective graphene-only Hamiltonians are derived from symmetry considerations, while a microscopic tight-binding approach connects effective low-energy couplings and graphene-adatom hybridization parameters. Within the T-matrix formalism, a theory for (spin-dependent) scattering events involving graphene's charge carriers, and the spin-orbit active adatoms is developed. Spin currents associated with intravalley and intervalley scattering are found to tend to oppose each other. We establish that under certain conditions, hollow-position adatoms give rise to the spin Hall effect, through skew scattering, while top-position adatoms induce transverse charge currents via trigonal potential scattering. We also identify the critical Fermi energy range where the spin Hall effect is dramatically enhanced, and the associated transverse spin currents can be reversed.

  10. US--ITER activation analysis

    SciTech Connect

    Attaya, H.; Gohar, Y.; Smith, D.

    1990-09-01

    Activation analysis has been made for the US ITER design. The radioactivity and the decay heat have been calculated, during operation and after shutdown for the two ITER phases, the Physics Phase and the Technology Phase. The Physics Phase operates about 24 full power days (FPDs) at fusion power level of 1100 MW and the Technology Phase has 860 MW fusion power and operates for about 1360 FPDs. The point-wise gamma sources have been calculated everywhere in the reactor at several times after shutdown of the two phases and are then used to calculate the biological dose everywhere in the reactor. Activation calculations have been made also for ITER divertor. The results are presented for different continuous operation times and for only one pulse. The effect of the pulsed operation on the radioactivity is analyzed. 6 refs., 12 figs., 1 tab.

  11. Prompt-gamma activation analysis

    SciTech Connect

    Lindstrom, R.M.

    1993-01-01

    A permenent, full-time instrument for prompt-gamma activation analysis is nearing completion as part of the Cold Neutron Research Facility (CNRF). The design of the analytical system has been optimized for high gamma detection efficiency and low background, particularly for hydrogen. Because of the purity of the neutron beam, shielding requirements are modest and the scatter-capture background is low. As a result of a compact sample-detector geometry, the sensitivity (counting rate per gram of analyte) is a factor of four better than the existing Maryland-NIST thermal-neutron instrument at the reactor. Hydrogen backgrounds of a few micrograms have already been achieved, which promises to be of value in numerous applications where quantitative nondestructive analysis of small quantities of hydrogen in materials is necessary.

  12. 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…

  13. 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…

  14. Activity Theory as a Framework for Project Work in Learning Environments.

    ERIC Educational Resources Information Center

    Hung, David W. L.; Wong, Angela F. L.

    2000-01-01

    Proposes activity theory as a framework for student project work that is a form of open-ended contextual activity-based learning emphasizing problem solving as a collaborative effort. Topics include project work from a Vygotskian perspective of activity theory; and the design of a prototype for Web-based project work. (LRW)

  15. A Re-Examination of Information Seeking Behaviour in the Context of Activity Theory

    ERIC Educational Resources Information Center

    Wilson, T. D.

    2006-01-01

    Introduction: Activity theory, developed in the USSR as a Marxist alternative to Western psychology, has been applied widely in educational studies and increasingly in human-computer interaction research. Argument: The key elements of activity theory, Motivation, Goal, Activity, Tools, Object, Outcome, Rules, Community and Division of labour are…

  16. Development and validation of the theory of planned behavior questionnaire in physical activity.

    PubMed

    Tirado González, Sonia; Neipp López, M Carmen; Quiles Marcos, Yolanda; Rodríguez-Marín, Jesús

    2012-07-01

    The Theory of Planned Behavior (TPB) is one of the main theoretical models in the study of the different variables, which influence in the practise of physical activity. The aim in this study was to develop a questionnaire based on TPB in physical activity context providing evidence for the validity of the obtained measures. The instrumental project included three independent studies. The first study entailed the construction and qualitative assessment of the items. In the second study, the analysis of factorial structure was performed by means of exploratory measures, and it showed that the reliability of measures was adequate. The third study provided evidence on the dimensionality of the scale. The confirmatory factorial analysis guaranteed the stability of factorial structure proposed by the TPB and provided evidence for the internal validity of the inventory. Moreover, this study provided evidence of its external validity.

  17. Mediation of personality influences on physical activity within the theory of planned behaviour.

    PubMed

    McEachan, Rosemary R C; Sutton, Stephen; Myers, Lynn

    2010-11-01

    This study estimated the effect of extraversion, conscientiousness and variables from a modified two-component Theory of Planned Behaviour (TPB) on prospective self-reported physical activity (N = 397). Mediation analysis using structural equation modelling with bootstrapping suggested that only conscientiousness had significant effects on intention and behaviour. Affective attitude and perceived behavioural control partially mediated the effect on intention. The effect on behaviour was significantly mediated by TPB variables consistent with partial or total mediation. The modified TPB mediates the effects of conscientiousness on intention and behaviour; it is unclear whether it is sufficient to mediate all of the effect on behaviour.

  18. 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

  19. 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…

  20. 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…

  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. 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…

  3. Ground movement analysis based on stochastic medium theory.

    PubMed

    Fei, Meng; Wu, Li-chun; Zhang, Jia-sheng; Deng, Guo-dong; Ni, Zhi-hui

    2014-01-01

    In order to calculate the ground movement induced by displacement piles driven into horizontal layered strata, an axisymmetric model was built and then the vertical and horizontal ground movement functions were deduced using stochastic medium theory. Results show that the vertical ground movement obeys normal distribution function, while the horizontal ground movement is an exponential function. Utilizing field measured data, parameters of these functions can be obtained by back analysis, and an example was employed to verify this model. Result shows that stochastic medium theory is suitable for calculating the ground movement in pile driving, and there is no need to consider the constitutive model of soil or contact between pile and soil. This method is applicable in practice. PMID:24701184

  4. 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

  5. Novel theory analysis and new perspective on angular selectivity

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Qi, Hongji; Wang, Hu; Chai, Yingjie; Sun, Wei; Hou, Yongqiang; Yi, Kui; Shao, Jianda

    2014-08-01

    Wave propagation of symmetry incidence on the biaxial birefringent film is discussed in this paper based on the characteristic matrix method. Furthermore, based on the refractive index surface, the refractive indices and effective optical admittances of the forward and backward propagating extraordinary waves (p-polarized wave) are analyzed in detail. With regard to the symmetry incidence, optical properties, such as the input optical admittance, transmittance and reflectance, are not identical for an extraordinary wave under common condition, i.e., angular selectivity. Based on an analysis of refractive index surface, the effective optical admittances of the forward and backward propagating extraordinary waves are equal in this particular case; transmittance and reflectance under the symmetry incidence are completely overlapped, similar to findings in the isotropic thin film. We validate our analysis using the developed software package. Based on the novel theory analysis, we can gain a new perspective of symmetry incidence about angular selectivity for the biaxial birefringent film.

  6. 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…

  7. Self-Conception and Life Satisfaction: Integrating Aged Subculture and Activity Theory.

    ERIC Educational Resources Information Center

    McClelland, Kent A.

    1982-01-01

    Integrates the traditional activity theory explanation of adjustment to aging with the aged subculture theory advanced by Rose. A path model to data from two subsamples of older adults. Self-conception is shown to be an important intervening variable between social activity and life satisfaction. (Author)

  8. Scattering-theory analysis of waveguide-resonator coupling

    PubMed

    Xu; Li; Lee; Yariv

    2000-11-01

    Using a formalism similar to the quantum scattering theory, we analyze the problem of coupling between optical waveguides and high Q resonators. We give the optical transmission and reflection coefficients as functions of the waveguide-resonator coupling, cavity loss (gain), and cavity resonant frequency. Based on these results, the recently proposed concept of "critical coupling" is discussed. Using a matrix formalism based on the scattering analysis, we find the dispersion relation of indirectly coupled resonator optical waveguides. The coupling between waveguides and multiple cavities is investigated and the reflection and transmission coefficients are derived.

  9. 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…

  10. 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.

  11. Item response theory analysis of the mechanics baseline test

    NASA Astrophysics Data System (ADS)

    Cardamone, Caroline N.; Abbott, Jonathan E.; Rayyan, Saif; Seaton, Daniel T.; Pawl, Andrew; Pritchard, David E.

    2012-02-01

    Item response theory is useful in both the development and evaluation of assessments and in computing standardized measures of student performance. In item response theory, individual parameters (difficulty, discrimination) for each item or question are fit by item response models. These parameters provide a means for evaluating a test and offer a better measure of student skill than a raw test score, because each skill calculation considers not only the number of questions answered correctly, but the individual properties of all questions answered. Here, we present the results from an analysis of the Mechanics Baseline Test given at MIT during 2005-2010. Using the item parameters, we identify questions on the Mechanics Baseline Test that are not effective in discriminating between MIT students of different abilities. We show that a limited subset of the highest quality questions on the Mechanics Baseline Test returns accurate measures of student skill. We compare student skills as determined by item response theory to the more traditional measurement of the raw score and show that a comparable measure of learning gain can be computed.

  12. 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

  13. 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.

  14. Application of portfolio theory in decision tree analysis.

    PubMed

    Galligan, D T; Ramberg, C; Curtis, C; Ferguson, J; Fetrow, J

    1991-07-01

    A general application of portfolio analysis for herd decision tree analysis is described. In the herd environment, this methodology offers a means of employing population-based decision strategies that can help the producer control economic variation in expected return from a given set of decision options. An economic decision tree model regarding the use of prostaglandin in dairy cows with undetected estrus was used to determine the expected return of the decisions to use prostaglandin and breed on a timed basis, use prostaglandin and then breed on sign of estrus, or breed on signs of estrus. The risk attributes of these decision alternatives were calculated from the decision tree, and portfolio theory was used to find the efficient decision combinations (portfolios with the highest return for a given variance). The resulting combinations of decisions could be used to control return variation.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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…

  20. 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.

  1. 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.

  2. 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…

  3. 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.

  4. 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

  5. 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.

  6. How media campaigns influence children's physical activity: expanding the normative mechanisms of the theory of planned behavior.

    PubMed

    Paek, Hye-Jin; Oh, Hyun Jung; Hove, Thomas

    2012-01-01

    This study explicates mechanisms of media campaign effectiveness in the context of children's physical activity. The authors' model expands the theory of planned behavior by integrating injunctive and descriptive norms into its normative mechanism. Analysis of a 3-wave nationally representative evaluation survey among 1,623 tweens indicates that campaign exposure is significantly related, but only indirectly, to both physical activity intention and physical activity behavior. Instead, campaign exposure seems more strongly related to perceived behavioral control and attitudes toward physical activity. By contrast, perceived behavioral control and descriptive norms are strongly related to behavioral intention. The findings suggest that integrating normative mechanisms with the theory of planned behavior can improve efforts to predict and explain a health behavior.

  7. 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.

  8. 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

  9. Energy analysis: a review of theory and applications. Final report

    SciTech Connect

    Peet, N.J.; Baines, J.T.

    1986-02-01

    Energy analysis is a means of developing a precise physical description of the operation of real-world processes. Its main application is in the determination of the energy consequences of carrying out physical activities such as the production of goods and services in an economy. To a significant extent, energy analysis has grown up because of what a number of workers believe to be inadequacies in the ability of conventional economic methodologies to handle problems relating to the use of resources, particularly nonrenewable reserves of fossil fuel. The review describes the history and development of energy analysis, its theoretical origins in thermodynamics, and its applications. The different perspectives of energetic and economic methods of analysis are contrasted, and their conflicts and complementarities are illuminated.

  10. 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.

  11. 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.

  12. The journey of an integrationist: A grounded theory analysis.

    PubMed

    Rihacek, Tomas; Danelova, Ester

    2016-03-01

    Surveys among psychotherapists tend to show a high preference for integrationism/eclecticism. There is, however, a lack of empirical studies exploring the process by which these psychotherapists arrive at this orientation. To answer this question, 22 autobiographies published by integrative psychotherapists were analyzed using grounded theory analytic procedures. The analysis resulted in a 3-stage developmental model, consisting of (a) the Adherence Phase, (b) the Destabilization Phase, and (c) the Consolidation Phase. The results are discussed in relation to several speculative models of psychotherapist development toward integration, as well as empirical literature on psychotherapist development. The results suggest that the tendency toward integration is best regarded as a natural part of the process of psychotherapist development. PMID:26785357

  13. 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.

  14. 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…

  15. 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

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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

  2. 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.

  3. Korean immigrant women's physical activity experience: a situation-specific theory.

    PubMed

    Im, Eun-Ok; Chang, Sun Ju; Nguyen, Giang; Stringer, Lynn; Chee, Wonshik; Chee, Eunice

    2015-01-01

    To develop successful physical activity promotion programs for midlife immigrant women, especially for Korean immigrant midlife women, concrete theoretical bases are needed. However, virtually no theoretical frameworks and/or theories exist that can explain the influences of immigration transition on the physical activity experience of midlife immigrant women in general or Korean immigrant midlife women in specific. The purpose of this article is to present a situation-specific theory on physical activity experience of Korean immigrant midlife women (SPAKIM) with its development process. An integrative approach was used to develop the theory based on the midlife women's attitudes toward physical activity (MAPA) theory, the transitions theory, a review of the relevant literature, and two studies on midlife women's attitudes toward physical activity. The proposed theory includes nature of transitions, nonmodifiable and modifiable transition conditions, contexts of daily life, patterns of response, and nursing therapeutics as major concepts, and each major concept includes several related subconcepts. Because several concepts of the theory were developed mainly based on the literature review, the major concepts and related subconcepts need to be further developed and evaluated in future studies.

  4. Nonlinear Analysis: Catastrophe Theory Modeling and Cobb's Cusp Surface Analysis Program.

    ERIC Educational Resources Information Center

    Allen, Bradford D.; Carifio, James

    1995-01-01

    Cobb's Cusp Surface Analysis Program (CUSP) provides a way to estimate empirically and test a nonlinear cusp catastrophe model. A model of emotion during problem solving is used to introduce catastrophe theory modeling and is discussed in conjunction with how to run and interpret CUSP. (SLD)

  5. 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.

  6. 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

  7. Emphasizing Saddle Points through Game Theory: A Classroom Activity.

    ERIC Educational Resources Information Center

    Dorrington, Jenny; Jones, Michael A.

    2000-01-01

    Introduces the necessary game-theoretic background and explains how game-theoretic experiments of the Matching Pennies game can be used as a classroom activity to develop intuition about saddle points. (Author/ASK)

  8. 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…

  9. 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.

  10. 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.

  11. 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

  12. Evaluation of physical activity web sites for use of behavior change theories.

    PubMed

    Doshi, Amol; Patrick, Kevin; Sallis, James F; Calfas, Karen

    2003-01-01

    Physical activity (PA) Web sites were assessed for their use of behavior change theories, including constructs of the health belief model, Transtheoretical Model, social cognitive theory, and the theory of reasoned action and planned behavior. An evaluation template for assessing PA Web sites was developed, and content validity and interrater reliability were demonstrated. Two independent raters evaluated 24 PA Web sites. Web sites varied widely in application of theory-based constructs, ranging from 5 to 48 on a 100-point scale. The most common intervention strategies were general information, social support, and realistic goal areas. Coverage of theory-based strategies was low, varying from 26% for social cognitive theory to 39% for health belief model. Overall, PA Web sites provided little assessment, feedback, or individually tailored assistance for users. They were unable to substantially tailor the on-line experience for users at different stages of change or different demographic characteristics.

  13. 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.

  14. 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

  15. 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,…

  16. Investigating Children's Musical Interactions within the Activities Systems of Group Composing and Arranging: An Application of Engestrom's Activity Theory

    ERIC Educational Resources Information Center

    Burnard, Pamela; Younker, Betty Anne

    2008-01-01

    This article applies Engestrom's Activity Theory (AT) as an analytical lens to identify defining characteristics of the collaborative creative music making activities of composing and arranging. Attention is paid to the complex interrelationships among the various elements of interaction in children's collaborative creative music making as…

  17. 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

  18. 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

  19. Neutron activation analysis of a penny

    NASA Astrophysics Data System (ADS)

    Stevens, Richard E.

    2000-04-01

    Neutron activation analysis has been used for many years as an analysis tool and as an educational tool to teach students about nuclear properties. This article presents an exercise in the neutron activation analysis of a penny which, due to the simplicity of the resulting gamma-ray spectra, is appropriate for general physics classes. Students express a great deal of interest both in seeing the reactor in use as well as determining the composition of something that is familiar to them.

  20. 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,…

  1. 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…

  2. 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…

  3. LACBWR primary shield activation analysis

    SciTech Connect

    Nelson, L.L.; Lahti, G.P.; Johnson, W.J.

    1996-11-01

    Nuclear power plants in the US are required to estimate the costs of decommissioning to ensure that adequate funds are accumulated during the useful life of the plant. A major component of the decommissioning cost is the disposal of radioactive material, including material near the reactor created by neutron activation. An accurate assessment of the residual radioactivity in the reactor`s primary shield is necessary to determine this portion of the decommissioning demolition and disposal cost. This paper describes the efforts used to determine the activation levels remaining in the primary shield of the LaCrosse boiling water reactor (LACBWR), owned and operated by Dairyland Power Cooperative.

  4. 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…

  5. Activity Theory as a Framework for Analysing Knowledge Building

    ERIC Educational Resources Information Center

    Van Aalst, Jan; Hill, Cher M.

    2006-01-01

    Content analyses of computer databases parsed into notes or ideas do not shed adequate light on the role of collaboration and the Computer-Supported Collaborative Learning environment in knowledge building; analysis of what is happening in the classroom and how students interpret that is also needed. This study used ethnographic methods to explore…

  6. 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.

  7. 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.

  8. 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

  9. Analysis of gene translation using a communications theory approach.

    PubMed

    Al Bataineh, Mohammad; Huang, Lun; Alonso, Maria; Menhart, Nick; Atkin, Guillermo E

    2010-01-01

    Rapid advances in both genomic data acquisition and computational technology have encouraged the development and use of advanced engineering methods in the field of bioinformatics and computational genomics. Processes in molecular biology can be modeled through the use of these methods. Such processes include identification and annotation of all the functional elements in the genome, including genes and regulatory sequences, which are a fundamental challenge in genomics and computational biology. Since regulatory elements are often short and variable, their identification and discovery using computational algorithms is difficult. However, significant advances have been made in the computational methods for modeling and detection of DNA regulatory elements. This paper proposes a novel use of techniques and principles from communications engineering, coding, and information theory for modeling, identification, and analysis of genomic regulatory elements and biological sequences. The methods proposed are not only able to identify regulatory elements (REs) at their exact locations, but can also "interestingly" distinguish coding from non-coding regions. Therefore, the proposed methods can be utilized to identify genes in the mRNA sequence.

  10. 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.

  11. 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…

  12. 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.

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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.

  1. 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

  2. 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…

  3. In defense of psychosomatic theory: a critical analysis of Allison and Heshka's critical analysis.

    PubMed

    Van Strien, T

    1995-04-01

    This article analyses Allison and Heshka's (Internal Journal of Eating Disorders, 13, 289-295, 1993.) critical analysis of studies supporting psychosomatic theory. Questionned first is, Allison and Heshka's contention that the obese overreport emotional eating as a result of effects of demand characteristics, social desirability, and interpersonal expectancies. These effects, however, indicate that a more plausible response would be an underreport of emotional eating. Also addressed is Allison and Heshka's (Eating Disorders: The Journal of Treatment and Prevention, 1, 31-38, 1993.) contention that a high correlation between a measurement instrument and a measure of social desirability invalidates that measurement instrument. Finally, in a rebuttal of Allison and Heshka's critical analysis of studies supporting psychosomatic theory, it is elaborated why emotional eating explains so little variance in weight gain and obesity.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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…

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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

  16. Solving the correspondence problem within the Ternus display: the differential-activation theory.

    PubMed

    Odic, Darko; Pratt, Jay

    2008-01-01

    The Ternus display produces a bistable illusion of motion: at very short interstimulus intervals (ISIs; < 30 ms) observers perceive element motion while at longer ISIs (> 30 ms) observers perceive group motion. In experiment 1, however, we find that, when the Ternus display's ISI contains an occluding box, group motion is mostly eliminated. These results do not fit the predictions made by the short-range/long-range two-process theory [Braddick and Adlard, 1978, in Visual Psychophysics and Psychology (New York: Academic Press)]. We propose that the differential-activation theory (Gilroy et al, 2001 Perception & Psychophysics 63 847-861) accounts for our results. We then extend the differential-activation theory as an explanatory mechanism for the Ternus display in experiment 2 by selectively placing an occluder over the first, second, or third Ternus display element. As predicted by the differential-activation theory, the occlusion of the far-left element produced a normal distribution of group motion increasing with ISI, while the occlusion of the other two elements produced an illusion of occluded elements remaining stationary throughout the display. Furthermore, as predicted by the differential-activation theory, each moving element was assigned to its nearest neighbour, producing, in the case of second and third element occlusion, a novel Ternus display motion illusion where only two out of three elements are perceived as moving. PMID:19227373

  17. 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

  18. 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.

  19. 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

  20. Between practice and theory: Melanie Klein, Anna Freud and the development of child analysis.

    PubMed

    Donaldson, G

    1996-04-01

    An examination of the early history of child analysis in the writings of Melanie Klein and Anna Freud reveals how two different and opposing approaches to child analysis arose at the same time. The two methods of child analysis are rooted in a differential emphasis on psychoanalytic theory and practice. The Kleinian method derives from the application of technique while the Anna Freudian method is driven by theory. Furthermore, by holding to the Freudian theory of child development Anna Freud was forced to limit the scope of child analysis, while Klein's application of Freudian practice has led to new discoveries about the development of the infant psyche.

  1. Between practice and theory: Melanie Klein, Anna Freud and the development of child analysis.

    PubMed

    Donaldson, G

    1996-04-01

    An examination of the early history of child analysis in the writings of Melanie Klein and Anna Freud reveals how two different and opposing approaches to child analysis arose at the same time. The two methods of child analysis are rooted in a differential emphasis on psychoanalytic theory and practice. The Kleinian method derives from the application of technique while the Anna Freudian method is driven by theory. Furthermore, by holding to the Freudian theory of child development Anna Freud was forced to limit the scope of child analysis, while Klein's application of Freudian practice has led to new discoveries about the development of the infant psyche. PMID:8642183

  2. Theory-based active ingredients of effective treatments for substance use disorders.

    PubMed

    Moos, Rudolf H

    2007-05-11

    This paper describes four related theories that specify common social processes that protect individuals from developing substance use disorders and may underlie effective psychosocial treatments for these disorders: social control theory, behavioral economics and behavioral choice theory, social learning theory, and stress and coping theory. It then provides an overview of the rationale and evidence for four effective psychosocial treatments for substance use disorders: motivational interviewing and motivational enhancement therapy, 12-step facilitation treatment, cognitive-behavioral treatment and behavioral family counseling, and contingency management and community reinforcement approaches. The presumed active ingredients of these treatments are described in terms of how they exemplify the social processes highlighted by the four theories. The identified common components of effective treatment include support, goal direction, and structure; an emphasis on rewards that compete with substance use, a focus on abstinence-oriented norms and models, and attempts to develop self-efficacy and coping skills. Several issues that need to be addressed to enhance our understanding of the active ingredients involved in effective treatment are discussed, including how to develop measures of these ingredients, how well the ingredients predict outcomes and influence conceptually comparable aspects of clients' life contexts, and how much their influence varies depending upon clients' demographic and personal characteristics.

  3. 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

  4. 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

  5. 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

  6. 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…

  7. 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.

  8. Human hair neutron activation analysis: Analysis on population level, mapping

    NASA Astrophysics Data System (ADS)

    Zhuk, L. I.; Kist, A. A.

    1999-01-01

    Neutron activation analysis is an outstanding analytical method having very wide applications in various fields. Analysis of human hair within last decades mostly based on neutron activation analysis is a very attractive illustration of the application of nuclear analytical techniques. Very interesting question is how the elemental composition differs in different areas or cities. In this connection the present paper gives average data and maps of various localities in the vicinity of drying-out Aral Sea and of various industrial cities in Central Asia.

  9. 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…

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. Radioactivity analysis in niobium activation foils

    SciTech Connect

    Mueller, G.E.

    1995-06-01

    The motivation for this study was to measure and analyze the activity of six (6) niobium (Nb) foils (the x-rays from an internal transition in Nb-93m) and apply this information with previously obtained activation foil data. The niobium data was used to determine the epithermal to MeV range for the neutron spectrum and fluence. The foil activation data was re-evaluated in a spectrum analysis code (STAY`SL) to provide new estimates of the exposure at the Los Alamos Spallation Radiation Effect Facility (LASREF). The activity of the niobium foils was measured and analyzed at the University of Missouri-Columbia (UMC) under the direction of Professor William Miller. The spectrum analysis was performed at the University of Missouri-Rolla (UMR) by Professor Gary Mueller.

  18. Patterns of brain activity supporting autobiographical memory, prospection, and theory of mind, and their relationship to the default mode network.

    PubMed

    Spreng, R Nathan; Grady, Cheryl L

    2010-06-01

    The ability to rise above the present environment and reflect upon the past, the future, and the minds of others is a fundamentally defining human feature. It has been proposed that these three self-referential processes involve a highly interconnected core set of brain structures known as the default mode network (DMN). The DMN appears to be active when individuals are engaged in stimulus-independent thought. This network is a likely candidate for supporting multiple processes, but this idea has not been tested directly. We used fMRI to examine brain activity during autobiographical remembering, prospection, and theory-of-mind reasoning. Using multivariate analyses, we found a common pattern of neural activation underlying all three processes in the DMN. In addition, autobiographical remembering and prospection engaged midline DMN structures to a greater degree and theory-of-mind reasoning engaged lateral DMN areas. A functional connectivity analysis revealed that activity of a critical node in the DMN, medial prefrontal cortex, was correlated with activity in other regions in the DMN during all three tasks. We conclude that the DMN supports common aspects of these cognitive behaviors involved in simulating an internalized experience.

  19. THE DEVELOPMENT OF GRAPHIC ACTIVITY IN THE CHILD--A THEORY AND A FIRST EXPERIMENT.

    ERIC Educational Resources Information Center

    GIBSON, JAMES J.; YONAS, PATRICIA

    THE THEORY OF VISIBLE DISPLAYS IMPLIES A CONNECTION BETWEEN THE DEVELOPMENT OF PERCEPTION IN THE CHILD AND THE DEVELOPMENT OF HIS CAPACITY TO MAKE THINGS THAT STIMULATE PERCEPTION. TO VERIFY THIS, TWO STUDIES ON THE FUNDAMENTAL GRAPHIC ACT AMONG YOUNG CHILDREN CONSIDERED MOTIVATING FACTORS LIKE THE PLEASURE OF MOVING, KINESTHESIS, ACTIVITY DRIVE,…

  20. 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…

  1. 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…

  2. 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…

  3. Activity Theory in Spanish Mixed Classrooms: Exploring Corrective Feedback as an Artifact

    ERIC Educational Resources Information Center

    Valentín-Rivera, Laura

    2016-01-01

    This study draws upon activity theory to better understand the implications of corrective feedback (CF) as an artifact on (1) the coconstruction of knowledge and (2) the action-oriented decisions of 10 mixed pairs comprising a foreign language learner (FLL) and a heritage language learner (HLL) of Spanish. To this end, the dyads were divided into…

  4. 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…

  5. 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…

  6. 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…

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. From Traditional to Constructivist Epistemologies: A Proposed Theoretical Framework Based on Activity Theory for Learning Communities

    ERIC Educational Resources Information Center

    Hung, David; Tan, Seng-Chee; Koh, Thiam-Seng

    2006-01-01

    This article is concerned with how learning communities are transformed as they evolve from traditional learning epistemologies towards constructivist orientations and pedagogies. Adopting activity theory as a framework, the article discusses how transformations take place through a two-way process of appropriation (learning from one another as a…

  16. 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…

  17. 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.

  18. 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…

  19. 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…

  20. 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…

  1. 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,…

  2. 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…

  3. Introducing Analysis of Conflict Theory Into the Social Science Classroom.

    ERIC Educational Resources Information Center

    Harris, Thomas E.

    The paper provides a simplified introduction to conflict theory through a series of in-class exercises. Conflict resolution, defined as negotiated settlement, can occur through three forms of communication: tacit, implicit, and explicit. Tacit communication, taking place without face-to-face or written interaction, refers to inferences made and…

  4. 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…

  5. 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…

  6. The Pedagogical Theories of A. S. Makarenko: A Comparative Analysis.

    ERIC Educational Resources Information Center

    Caskey, Bob

    1979-01-01

    Describes the career and methods of A. S. Makarenko, revered in the Soviet Union for his successful work with children abandoned in the Civil War (1918-1921). Evolution of his theories in later Soviet education is traced and comparisons made with institutions for homeless or delinquent youth in other countries. (SJL)

  7. C. elegans locomotion analysis using algorithmic information theory.

    PubMed

    Skandari, Roghieh; Le Bihan, Nicolas; Manton, Jonathan H

    2015-01-01

    This article investigates the use of algorithmic information theory to analyse C. elegans datasets. The ability of complexity measures to detect similarity in animals' behaviours is demonstrated and their strengths are compared to methods such as histograms. Introduced quantities are illustrated on a couple of real two-dimensional C. elegans datasets to investigate the thermotaxis and chemotaxis behaviours.

  8. 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…

  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. The Functional Analysis of Dreams: A New Theory of Dreaming.

    ERIC Educational Resources Information Center

    Karle, Werner; And Others

    1980-01-01

    Presents a relatively new theoretical, clinical, and research approach to dreams. Describes the functional theory of dreams and contrasts the functional approach with the more familiar interpretive approach. Reviews the origins and later spin-offs of the interpretive approach. (Author)

  11. 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…

  12. 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…

  13. Self-determination theory and physical activity among breast cancer survivors.

    PubMed

    Milne, Helen M; Wallman, Karen E; Guilfoyle, Andrew; Gordon, Sandy; Corneya, Kerry S

    2008-02-01

    The study aim was to examine constructs of autonomy support and competence as well as the motivation continuum from the self-determination theory (SDT) as a framework for understanding physical activity (PA) motivation and behavior in breast cancer survivors. Questionnaires assessing demographics, medical factors, PA, motivation continuum, perceived autonomy support, and competence were completed by 558 breast cancer survivors. Results showed that lymphedema (chi2 = 7.9, p < .01) (chi2 = 4.6, p < .05) were associated with meeting PA guidelines. Moreover, survivors meeting PA guidelines reported more identified regulations and intrinsic motivation (p < .01), autonomy support (p < .01), and competence (p < .01). Forced entry hierarchical regression analysis showed that SDT constructs explained 20.2% (p < .01) of the PA variance. Significant independent SDT predictors included identified regulation (Beta = .14, p < .05) and competence (Beta = .23, p < .01), with autonomy support approaching significance (Beta = .9, p = .057). SDT may be a useful model for understanding PA motivation and behavior in breast cancer survivors.

  14. 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.

  15. 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…

  16. 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),…

  17. An Analysis of Three Theories of the Relationships Among Reading Comprehension Skills.

    ERIC Educational Resources Information Center

    Chapman, Carita A.

    The focus in this analysis is on three theories of the relationships among reading comprehension skills primarily relating to the skills used in reading, not to the process or to the instructional procedures used for reading, as differentiated by Robinson. Consideration is given to three factors: (1) the existing need for theories and models in…

  18. 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…

  19. 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…

  20. 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…

  1. An Institutional Theory Analysis of Charter Schools: Addressing Institutional Challenges to Scale

    ERIC Educational Resources Information Center

    Huerta, Luis A.; Zuckerman, Andrew

    2009-01-01

    This article presents a conceptual framework derived from institutional theory in sociology that offers two competing policy contexts in which charter schools operate--a bureaucratic frame versus a decentralized frame. An analysis of evolving charter school types based on three underlying theories of action is considered. As charter school leaders…

  2. 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.

  3. Computer-automated neutron activation analysis system

    SciTech Connect

    Minor, M.M.; Garcia, S.R.

    1983-01-01

    An automated delayed neutron counting and instrumental neutron activation analysis system has been developed at Los Alamos National Laboratory's Omega West Reactor (OWR) to analyze samples for uranium and 31 additional elements with a maximum throughput of 400 samples per day. 5 references.

  4. 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.

  5. 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.

  6. On the use of information theory for the analysis of the relationship between neural and imaging signals.

    PubMed

    Panzeri, Stefano; Magri, Cesare; Logothetis, Nikos K

    2008-09-01

    Functional magnetic resonance imaging (fMRI) is a widely used method for studying the neural basis of cognition and of sensory function. A potential problem in the interpretation of fMRI data is that fMRI measures neural activity only indirectly, as a local change of deoxyhemoglobin concentration due to the metabolic demands of neural function. To build correct sensory and cognitive maps in the human brain, it is thus crucial to understand whether fMRI and neural activity convey the same type of information about external correlates. While a substantial experimental effort has been devoted to the simultaneous recordings of hemodynamic and neural signals, so far, the development of analysis methods that elucidate how neural and hemodynamic signals represent sensory information has received less attention. In this article, we critically review why the analytical framework of information theory, the mathematical theory of communication, is ideally suited to this purpose. We review the principles of information theory and explain how they could be applied to the analysis of fMRI and neural signals. We show that a critical advantage of information theory over more traditional analysis paradigms commonly used in the fMRI literature is that it can elucidate, within a single framework, whether an empirically observed correlation between neural and fMRI signals reflects either a similar stimulus tuning or a common source of variability unrelated to the external stimuli. In addition, information theory determines the extent to which these shared sources of stimulus signal and of variability lead fMRI and neural signals to convey similar information about external correlates. We then illustrate the formalism by applying it to the analysis of the information carried by different bands of the local field potential. We conclude by discussing the current methodological challenges that need to be addressed to make the information-theoretic approach more robustly applicable to the

  7. 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…

  8. 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

  9. 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.

  10. 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

  11. 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

  12. Effective field theory of dark matter: a global analysis

    NASA Astrophysics Data System (ADS)

    Liem, Sebastian; Bertone, Gianfranco; Calore, Francesca; de Austri, Roberto Ruiz; Tait, Tim M. P.; Trotta, Roberto; Weniger, Christoph

    2016-09-01

    We present global fits of an effective field theory description of real, and complex scalar dark matter candidates. We simultaneously take into account all possible dimension 6 operators consisting of dark matter bilinears and gauge invariant combinations of quark and gluon fields. We derive constraints on the free model parameters for both the real (five parameters) and complex (seven) scalar dark matter models obtained by combining Planck data on the cosmic microwave background, direct detection limits from LUX, and indirect detection limits from the Fermi Large Area Telescope. We find that for real scalars indirect dark matter searches disfavour a dark matter particle mass below 100 GeV. For the complex scalar dark matter particle current data have a limited impact due to the presence of operators that lead to p-wave annihilation, and also do not contribute to the spin-independent scattering cross-section. Although current data are not informative enough to strongly constrain the theory parameter space, we demonstrate the power of our formalism to reconstruct the theoretical parameters compatible with an actual dark matter detection, by assuming that the excess of gamma rays observed by the Fermi Large Area Telescope towards the Galactic centre is entirely due to dark matter annihilations. Please note that the excess can very well be due to astrophysical sources such as millisecond pulsars. We find that scalar dark matter interacting via effective field theory operators can in principle explain the Galactic centre excess, but that such interpretation is in strong tension with the non-detection of gamma rays from dwarf galaxies in the real scalar case. In the complex scalar case there is enough freedom to relieve the tension.

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

    PubMed

    Chou, Yen-Liang; Ihle, Thomas

    2015-02-01

    Recently, Hanke et al. [Phys. Rev. E 88, 052309 (2013)] 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.

  15. 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.

  16. 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.

  17. 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

  18. A signal detection theory analysis of the placebo effect.

    PubMed

    Allan, Lorraine G; Siegel, Shepard

    2002-12-01

    Some instances of the placebo effect may be understood as a particular type of error made by the patient--a false positive error. False positive errors are common (indeed, frequently encouraged) in medical decision making, both by diagnosticians and by patients, and are the inevitable consequence of concluding that an ambiguous signal (e.g., attenuation of pain, relief of depression) did, or did not, occur. Signal detection theory (SDT) was developed to model errors in the detection of ambiguous signals. The authors use SDT to understand the false positive errors that might be made by patients administered a placebo and termed a placebo effect.

  19. 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)

  20. 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…

  1. 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…

  2. 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.

  3. 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,…

  4. Negative emotions impact lateral prefrontal cortex activation during theory of mind: An fNIRS study.

    PubMed

    Himichi, Toshiyuki; Fujita, Hiroyo; Nomura, Michio

    2015-01-01

    The lateral prefrontal cortex (lPFC) plays a critical role in inhibiting self-perspective information, which is necessary for theory of mind (ToM) processing. Additionally, previous research has indicated that negative emotions interfere with lPFC activation during executive tasks. In this study, we hypothesized that negative emotions would inhibit lPFC activation during a ToM task. While female participants performed the director task following the observation of emotionally laden movies (neutral/negative/positive), their prefrontal hemodynamic activity was measured using near-infrared spectroscopy. After viewing the neutral movie, bilateral lPFC activity was significantly enhanced during ToM process compared to the control condition. In contrast, after viewing the negative movie, left lPFC activity during ToM process was significantly impaired. These results were interpreted to support the idea that negative emotions interfere with inhibition of self-perspective information through inactivation of the lPFC.

  5. Brief report: the theory of planned behaviour applied to physical activity in young people who smoke.

    PubMed

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

    2007-04-01

    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 activity and all TPB components. Physical activity behaviour was significantly explained by both intention and perceived behavioural control (PBC), with both intention and PBC making significant contributions to the model. Intention was significantly explained by attitude, subjective norm (SN) and PBC, with attitude, SN and PBC all making significant contributions to the model. The TPB may be a useful framework for guiding physical activity interventions among young smokers.

  6. 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.

  7. Research on Social Stability Mechanisms Based on Activation Energy and Gradual Activation Reaction Theory

    NASA Astrophysics Data System (ADS)

    Ning, Miao; Gu, Jifa

    This paper draws a comparison between social stability and chemical reaction process, and brings forward the concept of “social temperature” and “activation energy of social agent”. It is considered that social temperature turns out to be the macro symptom of social average energy, and its unceasing up-climbing roots in the energy accumulation of “inferiorization” process of social system; that “activation energy of social agent” stands for the social energy or temperature where individuals or groups reach the limit of their psychological bearing ability. This paper, basing on above concepts, elaborates on and demonstrates the gradual activation reaction mechanisms of social stability by a lot of concrete examples. It is thought that there is a threshold value for social stability, and the society will be unstable if social temperature goes higher than this value; that the larger the social average activation energy is, the higher the temperature threshold value of social stability will be; and considering that different groups have different activation energy, those fragile groups with low activation energy are often the risk source which might pose a threat to social stability.

  8. 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.

  9. 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.

  10. Effective field theory analysis of the self-interacting chameleon

    NASA Astrophysics Data System (ADS)

    Sanctuary, Hillary; Sturani, Riccardo

    2010-08-01

    We analyse the phenomenology of a self-interacting scalar field in the context of the chameleon scenario originally proposed by Khoury and Weltman. In the absence of self-interactions, this type of scalar field can mediate long range interactions and simultaneously evade constraints from violation of the weak equivalence principle. By applying to such a scalar field the effective field theory method proposed for Einstein gravity by Goldberger and Rothstein, we give a thorough perturbative evaluation of the importance of non-derivative self-interactions in determining the strength of the chameleon mediated force in the case of orbital motion. The self-interactions are potentially dangerous as they can change the long range behaviour of the field. Nevertheless, we show that they do not lead to any dramatic phenomenological consequence with respect to the linear case and solar system constraints are fulfilled.

  11. 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.

  12. Demographic and Motivation Differences Among Online Sex Offenders by Type of Offense: An Exploration of Routine Activities Theories.

    PubMed

    Navarro, Jordana N; Jasinski, Jana L

    2015-01-01

    This article presents an analysis of the relationship between online sexual offenders' demographic background and characteristics indicative of motivation and offense type. Specifically, we investigate whether these characteristics can distinguish different online sexual offender groups from one another as well as inform routine activity theorists on what potentially motivates perpetrators. Using multinomial logistic regression, this study found that online sexual offenders' demographic backgrounds and characteristics indicative of motivation do vary by offense types. Two important implications of this study are that the term "online sexual offender" encompasses different types of offenders, including some who do not align with mainstream media's characterization of "predators," and that the potential offender within routine activity theory can be the focus of empirical investigation rather than taken as a given in research.

  13. NDARC NASA Design and Analysis of Rotorcraft Theory Appendix 1

    NASA Technical Reports Server (NTRS)

    Johnson, Wayne

    2016-01-01

    The NASA Design and Analysis of Rotorcraft (NDARC) software is an aircraft system analysis tool that supports both conceptual design efforts and technology impact assessments. The principal tasks are to design (or size) a rotorcraft to meet specified requirements, including vertical takeoff and landing (VTOL) operation, and then analyze the performance of the aircraft for a set of conditions. For broad and lasting utility, it is important that the code have the capability to model general rotorcraft configurations, and estimate the performance and weights of advanced rotor concepts. The architecture of the NDARC code accommodates configuration flexibility, a hierarchy of models, and ultimately multidisciplinary design, analysis, and optimization. Initially the software is implemented with low-fidelity models, typically appropriate for the conceptual design environment. An NDARC job consists of one or more cases, each case optionally performing design and analysis tasks. The design task involves sizing the rotorcraft to satisfy specified design conditions and missions. The analysis tasks can include off-design mission performance calculation, flight performance calculation for point operating conditions, and generation of subsystem or component performance maps. For analysis tasks, the aircraft description can come from the sizing task, from a previous case or a previous NDARC job, or be independently generated (typically the description of an existing aircraft). The aircraft consists of a set of components, including fuselage, rotors, wings, tails, and propulsion. For each component, attributes such as performance, drag, and weight can be calculated; and the aircraft attributes are obtained from the sum of the component attributes. Description and analysis of conventional rotorcraft configurations is facilitated, while retaining the capability to model novel and advanced concepts. Specific rotorcraft configurations considered are single-main-rotor and tail

  14. Elastically Cooperative Activated Barrier Hopping Theory of Relaxation in Viscous Fluids. II. Thermal Liquids

    SciTech Connect

    Mirigian, Stephen; Schweizer, Kenneth

    2014-01-01

    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.

  15. 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.

  16. 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.

  17. 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.

  18. Activity Theory and the New Literacy Studies: Modelling the Literacy Learning Activity System.

    ERIC Educational Resources Information Center

    Kostogriz, Alexander

    This paper explores a number of implications arising from the combination of the New Literacy Studies and cultural-historical psychology--in particular, the concept of literacy as social practice and the psychological category of activity. Placing "social" at the center of literacy and psychological studies, these two perspectives are fruitfully…

  19. 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.

  20. 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].

  1. Sensitivity Theory and Mental Retardation: Why Functional Analysis Is Not Enough.

    ERIC Educational Resources Information Center

    Reiss, Steven; Havercamp, Susan M.

    1997-01-01

    Discusses problems of using applied behavior analysis for individuals with mental retardation who have behavior disorders and presents a sensitivity model of motivation that stresses analysis in terms of aberrant environments, aberrant contingencies, and aberrant motivation. Describes implications for communication theory, assessment, and…

  2. [Fractal theory and its application in the analysis of soil spatial variability: a review].

    PubMed

    Zhang, Fa-Sheng; Liu, Zuo-Xin

    2011-05-01

    Soil has spatial variability in its attributes. The analysis of soil spatial variability is of significance for soil management. This paper summarized the fractal theory and its application in spatial analysis of soil variability, with the focus on the utilization of moment method in calculating the fractal dimension of soil attributes, the multi-fractal analysis of soil spatial variability, and the scaling up of soil attributes based on multi-fractal parameters. The studies on the application of fractal theory and multi-fractal method in the analysis of soil spatial variability were also reviewed. Fractal theory could be an important tool in quantifying the spatial variability and scaling up of soil attributes.

  3. Protection motivation theory and physical activity in the general population: a systematic literature review.

    PubMed

    Bui, Linh; Mullan, Barbara; McCaffery, Kirsten

    2013-01-01

    An appropriate theoretical framework may be useful for guiding the development of physical activity interventions. This review investigates the effectiveness of the protection motivation theory (PMT), a model based on the cognitive mediation processes of behavioral change, in the prediction and promotion of physical activity participation. A literature search was conducted using the databases MEDLINE, PsycINFO, PubMed, and Web of Science, and a manual search was conducted on relevant reference lists. Studies were included if they tested or applied the PMT, measured physical activity, and sampled from healthy populations. A total of 20 studies were reviewed, grouped into four design categories: prediction, stage discrimination, experimental manipulation, and intervention. The results indicated that the PMT's coping appraisal construct of self-efficacy generally appears to be the most effective in predicting and promoting physical activity participation. In conclusion, the PMT shows some promise, however, there are still substantial gaps in the evidence.

  4. 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…

  5. 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…

  6. Theories of the Syllogism: A Meta-Analysis

    ERIC Educational Resources Information Center

    Khemlani, Sangeet; Johnson-Laird, P. N.

    2012-01-01

    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…

  7. 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…

  8. 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…

  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. Analysis of Rockbolt Reinforcement Using Beam-Column Theory

    NASA Astrophysics Data System (ADS)

    Roy, Samit; Rajagopalan, Anand B.

    1997-04-01

    A simple analytical procedure that applies classical beam-column theory for evaluating passive rockbolt roof reinforcement is presented in this paper. The analytical model is derived from first principles and is capable of modelling any number of reinforcing bolts. Each rockbolt is modelled as a linear spring and the model allows for non-uniform bolt spacing. In this study the rock beam is assumed to be isotropic and linearly elastic for the sake of simplicity. However, the analytical model can be extended to include anisotropic rockmass as well as inelastic material behaviour. The solution to the coupled set of governing equations is obtained by using a simple numerical solution procedure. The results from the analytical model indicate that the critical buckling load of a rock beam is strongly influenced by the ambient rock modulus. For salt-rock excavations the rock modulus typically declines with time due to various phenomena, and a diminished modulus could seriously compromise roof stability. The other main conclusion of this study is that rockbolts loose their effectiveness in restraining a roof beam once its critical buckling load is approached. In such a situation, increasing bolt stiffness does not improve its reinforcing action on a roof beam but it enhances the possibility of bolt failure due to anchor pull-out. Int. J. Numer. Anal. Meth. Geomech., vol. 21, 241-253 (1997)

  11. 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

  12. 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.

  13. 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

  14. [Analysis of humanistic theory and interpersonal relations of nurses in newborn care].

    PubMed

    Rolim, Karla Maria Carneiro; Pagliuca, Lorita Marlena Freitag; Leitão Cardoso, Maria Vera Lúcia M

    2005-01-01

    Theories are propositions created to evaluate nursing care, allowing nurses to consider and incorporate them in their professional practice. This Masters study was aimed at thinking critically about the practical usefulness of the concepts of Humanistic Nursing Theory. This descriptive-reflexive study was carried out in 2004 and used Meleis' model for the analysis of theories. The "critique of theory" segment was taken from this model to be used as an analytical tool, with emphasis on the "usefulness" parameter. The critical analysis revealed the notorious "usefulness" of interpersonal relations and dialogue, which can be used in daily practice at the Newborn Intensive Care Unit, valuing the human affective relations, which are essential for nursing care. Nursing practice should be guided by theoretical, philosophical, and methodological reference frameworks, responsible for making professionals reflect critically on themselves and their practice.

  15. 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

  16. Geographical Theories.

    ERIC Educational Resources Information Center

    Golledge, Reginald G.

    1996-01-01

    Discusses the origin of theories in geography and particularly the development of location theories. Considers the influence of economic theory on agricultural land use, industrial location, and geographic location theories. Explores a set of interrelated activities that show how the marketing process illustrates process theory. (MJP)

  17. 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.

  18. Theory of planned behavior and adherence in chronic illness: a meta-analysis.

    PubMed

    Rich, Antonia; Brandes, Kim; Mullan, Barbara; Hagger, Martin S

    2015-08-01

    Social-cognitive models such as the theory of planned behavior have demonstrated efficacy in predicting behavior, but few studies have examined the theory as a predictor of treatment adherence in chronic illness. We tested the efficacy of the theory for predicting adherence to treatment in chronic illness across multiple studies. A database search identified 27 studies, meeting inclusion criteria. Averaged intercorrelations among theory variables were computed corrected for sampling error using random-effects meta-analysis. Path-analysis using the meta-analytically derived correlations was used to test theory hypotheses and effects of moderators. The theory explained 33 and 9 % of the variance in intention and adherence behavior respectively. Theoretically consistent patterns of effects among the attitude, subjective norm, perceived behavioral control, intention and behavior constructs were found with small-to-medium effect sizes. Effect sizes were invariant across behavior and measurement type. Although results support theory predictions, effect sizes were small, particularly for the intention-behavior relationship.

  19. Qualitative research in healthcare: an introduction to grounded theory using thematic analysis.

    PubMed

    Chapman, A L; Hadfield, M; Chapman, C J

    2015-01-01

    In today's NHS, qualitative research is increasingly important as a method of assessing and improving quality of care. Grounded theory has developed as an analytical approach to qualitative data over the last 40 years. It is primarily an inductive process whereby theoretical insights are generated from data, in contrast to deductive research where theoretical hypotheses are tested via data collection. Grounded theory has been one of the main contributors to the acceptance of qualitative methods in a wide range of applied social sciences. The influence of grounded theory as an approach is, in part, based on its provision of an explicit framework for analysis and theory generation. Furthermore the stress upon grounding research in the reality of participants has also given it credence in healthcare research. As with all analytical approaches, grounded theory has drawbacks and limitations. It is important to have an understanding of these in order to assess the applicability of this approach to healthcare research. In this review we outline the principles of grounded theory, and focus on thematic analysis as the analytical approach used most frequently in grounded theory studies, with the aim of providing clinicians with the skills to critically review studies using this methodology.

  20. Implicit theories and youth mental health problems: a random-effects meta-analysis.

    PubMed

    Schleider, Jessica L; Abel, Madelaine R; Weisz, John R

    2015-02-01

    Compared to youths who believe that personal traits are malleable, those who believe that personal traits are fixed experience more academic and self-regulatory distress. Recently, studies have begun to explore relations between beliefs about the malleability of personal traits, or implicit theories, and youth mental health problems. We synthesized this emerging body of research in youths (ages 4-19) across 45 effect sizes from 17 research reports. Studies were included if they assessed youth mental health and implicit theories and did not manipulate implicit theory or affective/behavioral states prior to measuring these variables. Our random-effects meta-analysis using clustered data analysis techniques (i.e., effect sizes nested within samples) revealed that youths holding entity theories-the belief that personal traits are fixed-showed more pronounced mental health problems. This association between entity theories and mental health problems was evident across methodological factors and problem types (internalizing versus externalizing; psychopathology versus general distress). Limitations include the small number of eligible studies, insufficient data to test further demographic moderators, and few longitudinal studies on this topic. Overall, findings support the value of parsing the implicit theory-mental health link in youths. Implicit theories may prove to be promising targets for treatment and prevention of youth mental health problems.

  1. 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.

  2. A preliminary analysis of {eta}'{yields}{eta}{pi}{pi} in chiral theories

    SciTech Connect

    Escribano, R.

    2010-08-05

    Preliminary results for the Dalitz plot distribution of {eta}'{yields}{eta}{pi}{pi} decays in the frameworks of Large-N{sub c} Chiral Perturbation Theory and Resonance Chiral Theory are given. We hope our results to be of some relevance for the present and forthcoming analysis of these decays at GAMS, CLEO, VES, KLOE-2, Crystal Ball, Crystal Barrel, WASA, and BES-III.

  3. Wave-theory analysis of acousto-optic Bragg diffraction image formation.

    PubMed

    Mehrl, D J; Liu, Z C; Korpel, A

    1993-09-10

    We analyze anastigmatic Bragg diffraction imaging by use of an efficient numerical method that makes use of a plane-wave spectrum formalism applicable to weak acousto-optic diffraction involving threedimensional light and sound fields. Results from this wave-theory analysis are compared with previous results derived on the basis of ray theory, and are shown to be in good agreement, thus corroborating the validity of both techniques.

  4. Finite strip analysis of anisotropic laminated composite plates using higher-order shear deformation theory

    NASA Astrophysics Data System (ADS)

    Akhras, G.; Cheung, M. S.; Li, W.

    1994-08-01

    In the present study, a finite strip method for the elastic analysis of anisotropic laminated composite plates is developed according to higher-order shear deformation theory. This theory accounts for the parabolic distribution of the transverse shear strains through the thickness of the plate and for zero transverse shear stresses on the plate surfaces. In comparison with the finite strip method based on first-order shear deformation theory, the present method gives improved results while using approximately the same number of degrees of freedom. It also eliminates the need for shear correction factors in calculating the transverse shear stiffness.

  5. 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.

  6. 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

  7. Adult Attachment Ratings (AAR): An Item Response Theory Analysis

    PubMed Central

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

    2013-01-01

    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

  8. 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.

  9. Optical analysis of human eye using electromagnetic wave theory.

    PubMed

    Can, Melih G; Oner, Bilgehan B; Kurt, Hamza

    2013-10-01

    We present a two-dimensional electromagnetic analysis of light propagation through the human eye to examine the eye's optical properties. The electromagnetic approach has intriguing advantages over the conventional and frequently implemented ray optics analysis. The chromatic, spherical, and coma aberrations and the intensity of the focused light at the retina are computed in this work via full-wave analysis. We also investigate the effects of the cornea's and lens's curved structures on the focusing mechanism. The focal length and chromatic and spherical aberrations are observed to change owing to age-related refractive index variation in the lens. In addition, the effects of the lens and curvatures of the human eye on focusing are analyzed. Consequently, for both young and old human eye lenses, the differences due to the aberration variations, curvature surfaces, and gradient index are explored by the wave approach. The intensity distributions on the retina for both on- and off-axis illumination are calculated. A strong correlation between the locations of the nerve fibers and the intensity distribution is confirmed. On the basis of the findings, we can conclude that visual impairment due to deterioration of the human eye structure is more dramatic than that due to aging.

  10. 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.

  11. Using Activity Theory to Evaluate and Improve K-12 School and University Partnerships

    ERIC Educational Resources Information Center

    Yamagata-Lynch, Lisa C.; Smaldino, Sharon

    2007-01-01

    This article reports on an evaluation methodology development study for K-12 school and university partnerships. The method is based on Engestrom's (1987). "Learning by expanding: An activity-theoretical approach to developmental research". Helsinki: Orienta-Konsultit Oy activity systems analysis that allows researchers to examine qualitative…

  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. 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

  14. Unified Theory of Activated Relaxation in Liquids over 14 Decades in Time

    SciTech Connect

    Mirigian, Stephen; Schweizer, Kenneth

    2013-01-01

    We formulate a predictive theory at the level of forces of activated relaxation in hard-sphere fluids and thermal liquids that covers in a unified manner the apparent Arrhenius, crossover, and deeply supercooled regimes. The alpha relaxation event involves coupled cage-scale hopping and a long-range collective 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, resulting in a zeroth-order quasi-universal description. The theory is devoid of fit parameters, has no divergences at finite temperature nor below jamming, and captures the key features of the alpha time of molecular liquids from picoseconds to hundreds of seconds.

  15. 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.

  16. 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

  17. 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.

  18. A RE-AIM evaluation of theory-based physical activity interventions.

    PubMed

    Antikainen, Iina; Ellis, Rebecca

    2011-04-01

    Although physical activity interventions have been shown to effectively modify behavior, little research has examined the potential of these interventions for adoption in real-world settings. The purpose of this literature review was to evaluate the external validity of 57 theory-based physical activity interventions using the RE-AIM framework. The physical activity interventions included were more likely to report on issues of internal, rather than external validity and on individual, rather than organizational components of the RE-AIM framework, making the translation of many interventions into practice difficult. Furthermore, most studies included motivated, healthy participants, thus reducing the generalizability of the interventions to real-world settings that provide services to more diverse populations. To determine if a given intervention is feasible and effective in translational research, more information should be reported about the factors that affect external validity.

  19. 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.

  20. 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

  1. Theory of collisional electron spectroscopy for gas analysis

    SciTech Connect

    Panasyuk, George Y.; Tsyganov, Alexander B.

    2012-06-01

    We develop an analytical model for a proposed method of gas analysis. The method is based on collisional electron spectroscopy, where a limited number of electron scatterings on gas molecules inside the analyzer is permitted. The proposed method can be used to identify impurity species in a main gas from the resulted energy spectra of photoelectrons collected by the cathode. The photoelectrons are produced by vacuum ultraviolet-ionization of impurity species. Physical processes are explored in the case of detecting impurities in atmospheric air. The electron velocity distribution function inside the detector is derived. It is shown that the voltage dependence of the second derivative of the cathode current with respect to the applied cathode voltage can provide electron energy spectrum and subsequent identification of the impurity species.

  2. 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

  3. 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.

  4. Reliability assessment of different plate theories for elastic wave propagation analysis in functionally graded plates.

    PubMed

    Mehrkash, Milad; Azhari, Mojtaba; Mirdamadi, Hamid Reza

    2014-01-01

    The importance of elastic wave propagation problem in plates arises from the application of ultrasonic elastic waves in non-destructive evaluation of plate-like structures. However, precise study and analysis of acoustic guided waves especially in non-homogeneous waveguides such as functionally graded plates are so complicated that exact elastodynamic methods are rarely employed in practical applications. Thus, the simple approximate plate theories have attracted much interest for the calculation of wave fields in FGM plates. Therefore, in the current research, the classical plate theory (CPT), first-order shear deformation theory (FSDT) and third-order shear deformation theory (TSDT) are used to obtain the transient responses of flexural waves in FGM plates subjected to transverse impulsive loadings. Moreover, comparing the results with those based on a well recognized hybrid numerical method (HNM), we examine the accuracy of the plate theories for several plates of various thicknesses under excitations of different frequencies. The material properties of the plate are assumed to vary across the plate thickness according to a simple power-law distribution in terms of volume fractions of constituents. In all analyses, spatial Fourier transform together with modal analysis are applied to compute displacement responses of the plates. A comparison of the results demonstrates the reliability ranges of the approximate plate theories for elastic wave propagation analysis in FGM plates. Furthermore, based on various examples, it is shown that whenever the plate theories are used within the appropriate ranges of plate thickness and frequency content, solution process in wave number-time domain based on modal analysis approach is not only sufficient but also efficient for finding the transient waveforms in FGM plates.

  5. 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.

  6. 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.

  7. 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

  8. 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…

  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. Atomic force microscopy : theory and practice in bacteria morphostructural analysis.

    PubMed

    Braga, P C; Ricci, D

    2001-01-01

    The production of the first "microscope" between the end of the sixteenth and the beginning of the seventeenth century was a true breakthrough in the advance of civilization (1). Without the microscope, the natural, biological, medical, and other sciences would not be what they are today. After the optical microscope, a second breakthrough in the analysis of surface morphology occurred in the 1940s with the development of the scanning electron microscope (SEM). Instead of light (photons) and glass lenses, electrons and electromagnetic lenses (magnetic coils) are used to explore the sample. Optical and scanning (or transmission) electron microscopes are classified as "far field microscopes" because the distance between the sample and the point at which the image is obtained is long in comparison with the wavelengths of the photons or electrons involved. In this case, the image is a diffraction pattern and its resolution is wavelength limited (2, 3): in optical microscopy, resolution is determined by the Nyquist relation to the wavelength of the light used (typically about 1 μm); in a general purpose SEM, it is limited by the properties of the electromagnetic lenses (typically about 50Å) (4).

  11. Calculation of Raman optical activity spectra for vibrational analysis.

    PubMed

    Mutter, Shaun T; Zielinski, François; Popelier, Paul L A; Blanch, Ewan W

    2015-05-01

    By looking back on the history of Raman Optical Activity (ROA), the present article shows that the success of this analytical technique was for a long time hindered, paradoxically, by the deep level of detail and wealth of structural information it can provide. Basic principles of the underlying theory are discussed, to illustrate the technique's sensitivity due to its physical origins in the delicate response of molecular vibrations to electromagnetic properties. Following a short review of significant advances in the application of ROA by UK researchers, we dedicate two extensive sections to the technical and theoretical difficulties that were overcome to eventually provide predictive power to computational simulations in terms of ROA spectral calculation. In the last sections, we focus on a new modelling strategy that has been successful in coping with the dramatic impact of solvent effects on ROA analyses. This work emphasises the role of complementarity between experiment and theory for analysing the conformations and dynamics of biomolecules, so providing new perspectives for methodological improvements and molecular modelling development. For the latter, an example of a next-generation force-field for more accurate simulations and analysis of molecular behaviour is presented. By improving the accuracy of computational modelling, the analytical capabilities of ROA spectroscopy will be further developed so generating new insights into the complex behaviour of molecules.

  12. 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

  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.

  14. Promoting physical activity: development and testing of self-determination theory-based interventions.

    PubMed

    Fortier, Michelle S; Duda, Joan L; Guerin, Eva; Teixeira, Pedro J

    2012-03-02

    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.

  15. 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

  16. Interviews with the dead: using meta-life qualitative analysis to validate Hippocrates' theory of humours

    PubMed Central

    Secretion, F; Conjur, G S; Attitude, S P

    1998-01-01

    BACKGROUND: Hippocrates devised his theory of the 4 humours (blood, phlegm, black bile and yellow bile) 24 centuries ago. Since then, medicine has evolved into a complex body of confusing and sometimes contradictory facts. The authors, seeing a need to determine the validity of his theory, hired a psychic. METHODS: The psychic interviewed 4 eminent ancient physicians, including Hippocrates. A randomized double-blind cross-over design was used for this meta-life qualitative analysis. RESULTS: All of the interviewees agreed that the theory of humours is an accurate model to explain disease and personality. INTERPRETATION: Hiring a psychic to conduct after-death interviews with key informants is a useful way to validate scientific theories. PMID:9875254

  17. Analysis of the UCSF Symptom Management Theory: implications for pediatric oncology nursing.

    PubMed

    Linder, Lauri

    2010-01-01

    Symptom management research is a priority for both children and adults with cancer. The UCSF Symptom Management Theory (SMT) is a middle range theory depicting symptom management as a multidimensional process. A theory analysis using the process described by Walker and Avant evaluated the SMT with attention to application in research involving children with cancer. Application of the SMT in studies involving children has been limited to descriptive studies testing only portions of the theory. Findings of these studies have provided empiric support for the relationships proposed within the SMT. Considerations for future research involving children include attention to measurement of symptoms and clarity regarding the location of the parents and family within the model. With additional testing and refinement, the SMT has the potential to guide nursing research and practice to improve symptoms for children with cancer.

  18. 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…

  19. On the global well-posedness theory for a class of PDE models for criminal activity

    NASA Astrophysics Data System (ADS)

    Rodríguez, N.

    2013-10-01

    We study a class of ‘reaction-advection-diffusion’ system of partial differential equations, which can be taken as basic models for criminal activity. This class of models are based on routine activity theory and other theories, such as the ‘repeat and near-repeat victimization effect’ and were first introduced in Short et al. (2008) [11]. In these models the criminal density is advected by a velocity field that depends on a scalar field, which measures the appeal to commit a crime. We refer to this scalar field as the attractiveness field. We prove local well-posedness of solutions for the general class of models. Furthermore, we prove global well-posedness of solutions to a fully-parabolic system with a velocity field that depends logarithmically on the attractiveness field. Our final result is the global well-posedness of solutions the fully-parabolic system with velocity field that depends linearly on the attractiveness field for small initial mass.

  20. Using cultural-historical activity theory to study clinical reasoning in context.

    PubMed

    Toth-Cohen, Susan

    2008-06-01

    The aim of this paper is to describe sources of conflict and congruence in critical areas of practice with caregivers of persons with dementia, using cultural-historical activity theory as an analytic framework. Findings are drawn from an ethnographic study that described the context of occupational therapists' (OTs') clinical reasoning in a funded, home-based environmental skill-building program designed to help caregivers manage the daily care of a family member with dementia. Data were gathered through observation of intervention sessions, debriefing sessions, semi-structured interviews with therapists, and review of intervention documentation. Primary sources of conflict and congruence within the identified practice context included conflicts between therapists and caregivers concerning which environmental strategies were best for addressing problems in caregiving and expectations regarding OT and caregiver roles. Areas of congruence included the fit between intervention protocols used to guide treatment and the approaches therapists developed to help caregivers modify care receivers' living environments. The study revealed the complexity of OT practice and demonstrated that practice contexts can be systematically analyzed using cultural-historical activity theory to determine key factors influencing clinical reasoning. The approach also presents an alternative perspective on clinical reasoning that more directly integrates clients/caregivers and therapists as co-constructors of OT intervention.

  1. An Item Response Theory Analysis of the Mathematics Teaching Efficacy Beliefs Instrument

    ERIC Educational Resources Information Center

    Kieftenbeld, Vincent; Natesan, Prathiba; Eddy, Colleen

    2011-01-01

    The mathematics teaching efficacy beliefs of preservice elementary teachers have been the subject of several studies. A widely used measure in these studies is the Mathematics Teaching Efficacy Beliefs Instrument (MTEBI). The present study provides a detailed analysis of the psychometric properties of the MTEBI using Bayesian item response theory.…

  2. Commentary for Special Issue of Journal of Memory and Language: Generalizability Theory Analysis for Psycholinguistic Applications

    ERIC Educational Resources Information Center

    Figueredo, Aurelio Jose; Olderbak, Sally

    2008-01-01

    We propose that the continuing controversies over the use of quasi-"F"-ratios in psycholinguistic research might be circumvented, if not resolved, by the judicious application of Generalizability Theory (GT) analyses. We argue that GT is a logical extension of the basic rationale behind repeated measures Analysis of Variance (ANOVA) and the…

  3. Foundations Symposium: A Continued Dialogue on Critical Theory, Cultural Analysis, and Ethical Aspects of the Field.

    ERIC Educational Resources Information Center

    Anderson, Jane; And Others

    Seven articles are presented from a symposium on critical theory, cultural analysis, and the ethical aspects of the use of educational technology. Two papers deal with the educational philosophy of two modern thinkers, and others focus on educational technology in the modern or postmodern era. The following papers are included: (1) "Foucault and…

  4. 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…

  5. 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)

  6. On the Relationship Between Item Response Theory and Factor Analysis of Discretized Variables.

    ERIC Educational Resources Information Center

    Takane, Yoshio; de Leeuw, Jan

    1987-01-01

    Equivalence of marginal likelihood of the two-parameter normal ogive model in item response theory and factor analysis of dichotomized variables was formally proved. Ordered and unordered categorical data and paired comparisons data were discussed, and a taxonomy of data for the models was suggested. (Author/GDC)

  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. 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…

  9. 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…

  10. 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…

  11. 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 =…

  12. 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…

  13. 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…

  14. Confirmatory Factor Analysis of the Stanford-Binet Fourth Edition: Testing the Theory-Test Match.

    ERIC Educational Resources Information Center

    Keith, Timothy Z.; And Others

    1988-01-01

    Studied whether Stanford-Binet Intelligence Scale: Fourth Edition corresponds to theory that guided its construction, using first-order confirmatory factor analysis with entire standardization sample and three age groups. Results generally support the four factors as reflecting the underlying structure of the new Binet, but were less supportive of…

  15. 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…

  16. Analysis of physical activities in Taekwondo Pumsae.

    PubMed

    Lee, Sang-Bock; Cha, Eun-Jong; Lee, Tae-Soo

    2008-01-01

    Exercise is very important element for successful aging. Among many sports events, Korea is the suzerain of Taekwondo. When competing (Taekwondo Free Fighting) after learning Poomse as basic movements and inuring them, people compete with movements depending on situation. Among Poomses of Taekwondo, Taegeuk Poomse consists of very basic movements from 1 Jang to 8 Jang and they are for inuring to body. In order to prescribe Taegeuk Jang, which is the basic movement of Taekwondo that Korea is the suzerain, as an exercise for successful aging, it is necessary to analyze physical activity level of each Taegeuk Jang (From 1 Jang through 8 Jang) and suggest the same. Therefore, in this study, I analyzed physical activity level of each Jang of Taegeuk Poomse by attaching Armband made by Body Media Company on brachia and legs below knee of Taekwondo trainees. The result of the analysis of the whole momentum from Taegeuk 1 Jang to 8 Jang is as follows: First, the average absolute value of acceleration variation of vertical direction signal (L-MAD): 5.15. Second, the average absolute value of acceleration variation of horizontal direction signal (T-MAD): 3.44. Finally, the average of calorie consumption per minute (AEE/Min): 5.06 Cal. The obtained result corresponds to proper exercise condition for successful aging and it can be utilized as data for exercise prescription for the young and the old.

  17. 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.

  18. Analysis of retrotransposon activity in plants.

    PubMed

    Defraia, Christopher; Slotkin, R Keith

    2014-01-01

    Retrotransposons are transposable elements that duplicate themselves by converting their transcribed RNA genome into cDNA, which is then integrated back into the genome. Retrotransposons can be divided into two major classes based on their mechanism of transposition and the presence or absence of long terminal repeats (LTRs). In contrast to mammalian genomes, in which non-LTR retrotransposons have proliferated, plant genomes show evolutionary evidence of an explosion in LTR retrotransposon copy number. These retrotransposons can comprise a large fraction of the genome (75 % in maize). Although often viewed as molecular parasites, retrotransposons have been shown to influence neighboring gene expression and play a structural and potential regulatory role in the centromere. To prevent retrotransposon activity, eukaryotic cells have evolved overlapping mechanisms to repress transposition. Plants are an excellent system for studying the mechanisms of LTR retrotransposon inhibition such as DNA methylation and small RNA-mediated degradation of retrotransposon transcripts. However, analysis of these multi-copy, mobile elements is considerably more difficult than analysis of single-copy genes located in stable regions of the genome. In this chapter we outline methods for analyzing the progress of LTR retrotransposons through their replication cycle in plants. We describe a mixture of traditional molecular biology experiments, such as Southern, Northern, and Western blotting, in addition to nontraditional techniques designed to take advantage of the specific mechanism of LTR retrotransposition.

  19. 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

  20. 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

  1. 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

  2. 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…

  3. Assessing physical activity intensity by video analysis.

    PubMed

    Silva, P; Santiago, C; Reis, L P; Sousa, A; Mota, J; Welk, G

    2015-05-01

    Assessing physical activity (PA) is a challenging task and many different approaches have been proposed. Direct observation (DO) techniques can objectively code both the behavior and the context in which it occurred, however, they have significant limitations such as the cost and burden associated with collecting and processing data. Therefore, this study evaluated the utility of an automated video analysis system (CAM) designed to record and discriminate the intensity of PA using a subject tracking methodology. The relative utility of the CAM system and DO were compared with criterion data from an objective accelerometry-based device (Actigraph GT3X+). Eight 10 year old children (three girls and five boys) wore the GT3X+ during a standard basketball session. PA was analyzed by two observers using the SOPLAY instrument and by the CAM system. The GT3X+ and the CAM were both set up to collect data at 30 Hz while the DO was performed every two minutes, with 10 s of observation for each gender. The GT3X+ was processed using cut points by Evanson and the outcome measure was the percentage of time spent in different intensities of PA. The CAM data were processed similarly using the same speed thresholds as were used in establishing the Evenson cut-off points (light: <2 mph; walking: 2-4 mph; very active: >4 mph). Similar outcomes were computed from the SOPLAY default analyses. A chi-square test was used to test differences in the percentage of time at the three intensity zones (light, walking and very active). The Yates' correction was used to prevent overestimation of statistical significance for small data. When compared with GT3X+, the CAM had better results than the SOPLAY. The chi-square test yielded the following pairwise comparisons: CAM versus GT3x+ was χ(2) (5) = 24.18, p < .001; SOPLAY2 versus GT3x+ was χ(2) (5) = 144.44, p < .001; SOPLAY1 versus GT3x+ was χ(2) (5) = 119.55, p < .001. The differences were smaller between CAM and GT3x

  4. 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.

  5. Analysis of modern optimal control theory applied to plasma position and current control in TFTR

    SciTech Connect

    Firestone, M.A.

    1981-09-01

    The strong compression TFTR discharge has been segmented into regions where linear dynamics can approximate the plasma's interaction with the OH and EF power supply systems. The dynamic equations for these regions are utilized within the linear optimal control theory framework to provide active feedback gains to control the plasma position and current. Methods are developed to analyze and quantitatively evaluate the quality of control in a nonlinear, more realistic simulation. Tests are made of optimal control theory's assumptions and requirements, and the feasibility of this method for TFTR is assessed.

  6. 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.

  7. Analysis of the segmented contraction of basis functions using density matrix theory.

    PubMed

    Custodio, Rogério; Gomes, André Severo Pereira; Sensato, Fabrício Ronil; Trevas, Júlio Murilo Dos Santos

    2006-11-30

    A particular formulation based on density matrix (DM) theory at the Hartree-Fock level of theory and the description of the atomic orbitals as integral transforms is introduced. This formulation leads to a continuous representation of the density matrices as functions of a generator coordinate and to the possibility of plotting either the continuous or discrete density matrices as functions of the exponents of primitive Gaussian basis functions. The analysis of these diagrams provides useful information allowing: (a) the determination of the most important primitives for a given orbital, (b) the core-valence separation, and (c) support for the development of contracted basis sets by the segmented method.

  8. Activation Likelihood Estimation meta-analysis revisited

    PubMed Central

    Eickhoff, Simon B.; Bzdok, Danilo; Laird, Angela R.; Kurth, Florian; Fox, Peter T.

    2011-01-01

    A widely used technique for coordinate-based meta-analysis of neuroimaging data is activation likelihood estimation (ALE), which determines the convergence of foci reported from different experiments. ALE analysis involves modelling these foci as probability distributions whose width is based on empirical estimates of the spatial uncertainty due to the between-subject and between-template variability of neuroimaging data. ALE results are assessed against a null-distribution of random spatial association between experiments, resulting in random-effects inference. In the present revision of this algorithm, we address two remaining drawbacks of the previous algorithm. First, the assessment of spatial association between experiments was based on a highly time-consuming permutation test, which nevertheless entailed the danger of underestimating the right tail of the null-distribution. In this report, we outline how this previous approach may be replaced by a faster and more precise analytical method. Second, the previously applied correction procedure, i.e. controlling the false discovery rate (FDR), is supplemented by new approaches for correcting the family-wise error rate and the cluster-level significance. The different alternatives for drawing inference on meta-analytic results are evaluated on an exemplary dataset on face perception as well as discussed with respect to their methodological limitations and advantages. In summary, we thus replaced the previous permutation algorithm with a faster and more rigorous analytical solution for the null-distribution and comprehensively address the issue of multiple-comparison corrections. The proposed revision of the ALE-algorithm should provide an improved tool for conducting coordinate-based meta-analyses on functional imaging data. PMID:21963913

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Is the Pauwels' theory of hip biomechanics still valid? A critical analysis, based on modern methods.

    PubMed

    Kummer, B

    1993-06-01

    The Pauwels' theory of hip biomechanics assuming bending stresses of the proximal femur has been critisized by recent authors. Therefore, the fundamentals of the classic theory have been reviewed, analysed by means of modern methods, and completed. The conclusion is that, hypothetically, a totally bending-free skeletal scaffold could be obtained by muscular tear strings. The analysis of anatomical specimens and considerations on optimisation show, however, that the bending theory of the proximal femur gives still the best explanation for the observations. Furthermore, the classic model has to be completed by two important conditions: 1. The supporting foot must be positioned on the action line of the gravity force of the body, and 2. the abductorial forces on the hip (to balance the momentum of the body weight) is composed by the forces of the lesser glutei (70%) and the muscles tending the tractus iliotibialis (30%).

  17. 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.

  18. 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.

  19. 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.

  20. 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