A Validation Study of Maslow's Hierarchy of Needs Theory.

Science.gov (United States)

Clay, Rex J.

A study was conducted to expand the body of research that tests the validity of Abraham Maslow's hierarchy of needs theory in a work context where it often serves as a guide for the supervisor's relationships with his subordinates. Data was gathered by questionnaire which tested for a hierarchy of needs among instructors at four community colleges…

Validation of Theory of Consumption Values Scales for Deal Sites

DEFF Research Database (Denmark)

Sudzina, Frantisek

2016-01-01

Deal sites became a widely used artefact. But there is still only a limited number of papers investigating their adoption and use. Most of the research published on the topic is qualitative. It is typical for an early stage of investigation of any new artefact. The Theory of Consumption Values ex...... explains purchase behavior. The aim of this paper is to validate scales for the Theory of Consumption Values for deal sites. This should pave a way for quantitative investigation of motives for purchasing using deal sites....

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

Science.gov (United States)

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

Validation of a rapid, non-radioactive method to quantify internalisation of G-protein coupled receptors

NARCIS (Netherlands)

Jongsma, Maikel; Florczyk, Urszula M.; Hendriks-Balk, Marieelle C.; Michel, Martin C.; Peters, Stephan L. M.; Alewijnse, Astrid E.

2007-01-01

Agonist exposure can cause internalisation of G-protein coupled receptors (GPCRs), which may be a part of desensitisation but also of cellular signaling. Previous methods to study internalisation have been tedious or only poorly quantitative. Therefore, we have developed and validated a quantitative

Weak turbulence theory of Langmuir waves: A reconsideration of validity of quasilinear theory

International Nuclear Information System (INIS)

Liang, Y.M.; Diamond, P.H.

1991-01-01

The weak turbulence theory of Langmuir waves in a one-dimensional, one-species plasma is discussed. Analytical calculations using the theory of two-point correlation functions show that in the weak turbulence regime τ ac much-lt min[τ tr , γ k -1 ], the nonlinear enhancement of the mode growth rate relative to the linear Landau mode growth rate γ k L is rather weak, and quasilinear theory is reproduced at the lowest order. Hence this work also proves the validity of the quasilinear theory. Here τ ac ∼ (kΔv ph ) -1 is the phase-mixing time or the auto-correlation time, and τ tr ∼ (k 2 D ql ) -1/3 is the particle decorrelation time or the turbulence trapping time. In particular, the lowest order nonlinear correction to γ k L in the regime τ ac much-lt τ tr much-lt γ k -1 is proportional to (1/ω k τ tr )γ k L . Both corrections are additive, not multiplicative, and are of higher order in the weak turbulence expansion. The smallness of the corrections is due to the fact that the only mechanism for the relaxation of the plasma distribution function in a one-dimensional, one-species plasma is momentum exchange between waves and particles, which is exactly the interaction considered in the quasilinear theory. No like-like particle momentum exchange is allowed due to momentum conservation constraints. Similar calculations are also done for the traveling wave tube, which can be used to test this theory experimentally, especially for the case of bump-on-tail instability. A comparison of theoretical predictions with experimental results is presented. 3 refs

Four tenets of modern validity theory for medical education assessment and evaluation.

Science.gov (United States)

Royal, Kenneth D

2017-01-01

Validity is considered by many to be the most important criterion for evaluating a set of scores, yet few agree on what exactly the term means. Since the mid-1800s, scholars have been concerned with the notion of validity, but over time, the term has developed a variety of meanings across academic disciplines and contexts. Accordingly, when scholars with different academic backgrounds, many of whom hold deeply entrenched perspectives about validity conceptualizations, converge in the field of medical education assessment, it is a recipe for confusion. Thus, it is important to work toward a consensus about validity in the context of medical education assessment. Thus, the purpose of this work was to present four fundamental tenets of modern validity theory in an effort to establish a framework for scholars in the field of medical education assessment to follow when conceptualizing validity, interpreting validity evidence, and reporting research findings.

Validation of a rapid, non-radioactive method to quantify internalisation of G-protein coupled receptors.

Science.gov (United States)

Jongsma, Maikel; Florczyk, Urszula M; Hendriks-Balk, Mariëlle C; Michel, Martin C; Peters, Stephan L M; Alewijnse, Astrid E

2007-07-01

Agonist exposure can cause internalisation of G-protein coupled receptors (GPCRs), which may be a part of desensitisation but also of cellular signaling. Previous methods to study internalisation have been tedious or only poorly quantitative. Therefore, we have developed and validated a quantitative method using a sphingosine-1-phosphate (S1P) receptor as a model. Because of a lack of suitable binding studies, it has been difficult to study S1P receptor internalisation. Using a N-terminal HisG-tag, S1P(1) receptors on the cell membrane can be visualised via immunocytochemistry with a specific anti-HisG antibody. S1P-induced internalisation was concentration dependent and was quantified using a microplate reader, detecting either absorbance, a fluorescent or luminescent signal, depending on the antibodies used. Among those, the fluorescence detection method was the most convenient to use. The relative ease of this method makes it suitable to measure a large number of data points, e.g. to compare the potency and efficacy of receptor ligands.

Binding equilibrium and kinetics of membrane-anchored receptors and ligands in cell adhesion: Insights from computational model systems and theory

Science.gov (United States)

Weikl, Thomas R.; Hu, Jinglei; Xu, Guang-Kui; Lipowsky, Reinhard

2016-01-01

ABSTRACT The adhesion of cell membranes is mediated by the binding of membrane-anchored receptor and ligand proteins. In this article, we review recent results from simulations and theory that lead to novel insights on how the binding equilibrium and kinetics of these proteins is affected by the membranes and by the membrane anchoring and molecular properties of the proteins. Simulations and theory both indicate that the binding equilibrium constant K2D and the on- and off-rate constants of anchored receptors and ligands in their 2-dimensional (2D) membrane environment strongly depend on the membrane roughness from thermally excited shape fluctuations on nanoscales. Recent theory corroborated by simulations provides a general relation between K2D and the binding constant K3D of soluble variants of the receptors and ligands that lack the membrane anchors and are free to diffuse in 3 dimensions (3D). PMID:27294442

Binding constants of membrane-anchored receptors and ligands: A general theory corroborated by Monte Carlo simulations.

Science.gov (United States)

Xu, Guang-Kui; Hu, Jinglei; Lipowsky, Reinhard; Weikl, Thomas R

2015-12-28

Adhesion processes of biological membranes that enclose cells and cellular organelles are essential for immune responses, tissue formation, and signaling. These processes depend sensitively on the binding constant K2D of the membrane-anchored receptor and ligand proteins that mediate adhesion, which is difficult to measure in the "two-dimensional" (2D) membrane environment of the proteins. An important problem therefore is to relate K2D to the binding constant K3D of soluble variants of the receptors and ligands that lack the membrane anchors and are free to diffuse in three dimensions (3D). In this article, we present a general theory for the binding constants K2D and K3D of rather stiff proteins whose main degrees of freedom are translation and rotation, along membranes and around anchor points "in 2D," or unconstrained "in 3D." The theory generalizes previous results by describing how K2D depends both on the average separation and thermal nanoscale roughness of the apposing membranes, and on the length and anchoring flexibility of the receptors and ligands. Our theoretical results for the ratio K2D/K3D of the binding constants agree with detailed results from Monte Carlo simulations without any data fitting, which indicates that the theory captures the essential features of the "dimensionality reduction" due to membrane anchoring. In our Monte Carlo simulations, we consider a novel coarse-grained model of biomembrane adhesion in which the membranes are represented as discretized elastic surfaces, and the receptors and ligands as anchored molecules that diffuse continuously along the membranes and rotate at their anchor points.

Validation of Triphasic Mixture Theory for a Mimic of Intervertebral Disk Tissue

NARCIS (Netherlands)

Oomens, C.W.J.; Heus, de H.J.; Huyghe, J.M.R.J.; Nelissen, J.G.L.; Janssen, J.D.

1995-01-01

This paper describes experimental studies an synthetic madel materials that mimic the mechanical behavior af intervertebral disk tissue. The results are used ta validate the triphasic mixture theory to describe soft charged hydrated materiais. Permeability and swelling pressure experiments were used

Antibody Selection for Cancer Target Validation of FSH-Receptor in Immunohistochemical Settings

Directory of Open Access Journals (Sweden)

Nina Moeker

2017-10-01

Full Text Available Background: The follicle-stimulating hormone (FSH-receptor (FSHR has been reported to be an attractive target for antibody therapy in human cancer. However, divergent immunohistochemical (IHC findings have been reported for FSHR expression in tumor tissues, which could be due to the specificity of the antibodies used. Methods: Three frequently used antibodies (sc-7798, sc-13935, and FSHR323 were validated for their suitability in an immunohistochemical study for FSHR expression in different tissues. As quality control, two potential therapeutic anti-hFSHR Ylanthia® antibodies (Y010913, Y010916 were used. The specificity criteria for selection of antibodies were binding to native hFSHR of different sources, and no binding to non-related proteins. The ability of antibodies to stain the paraffin-embedded Flp-In Chinese hamster ovary (CHO/FSHR cells was tested after application of different epitope retrieval methods. Results: From the five tested anti-hFSHR antibodies, only Y010913, Y010916, and FSHR323 showed specific binding to native, cell-presented hFSHR. Since Ylanthia® antibodies were selected to specifically recognize native FSHR, as required for a potential therapeutic antibody candidate, FSHR323 was the only antibody to detect the receptor in IHC/histochemical settings on transfected cells, and at markedly lower, physiological concentrations (ex., in Sertoli cells of human testes. The pattern of FSH323 staining noticed for ovarian, prostatic, and renal adenocarcinomas indicated that FSHR was expressed mainly in the peripheral tumor blood vessels. Conclusion: Of all published IHC antibodies tested, only antibody FSHR323 proved suitable for target validation of hFSHR in an IHC setting for cancer. Our studies could not confirm the previously reported FSHR overexpression in ovarian and prostate cancer cells. Instead, specific overexpression in peripheral tumor blood vessels could be confirmed after thorough validation of the antibodies used.

Signalling with retinoids in the human lung: validation of new tools for the expression study of retinoid receptors

International Nuclear Information System (INIS)

Poulain, Stéphane; Lacomme, Stéphanie; Battaglia-Hsu, Shyue-Fang; Manoir, Stanislas du; Brochin, Lydia; Vignaud, Jean-Michel; Martinet, Nadine

2009-01-01

Retinoid Receptors are involved in development and cell homeostasis. Alterations of their expressions have been observed in lung cancer. However, retinoid chemoprevention trials in populations at risk to develop such tumors have failed. Therefore, the pertinence of new clinical trials using second generation retinoid requires prior better understanding of retinoid signalling. This is our aim when validating extensively research tools, focused on Retinoic Acid Receptor beta, whose major role in lung cancer is documented. Biocomputing was used to assess the genomic organization of RAR beta. Its putative RAR-beta1' promoter features were investigated experimentally. Specific measures realized, with qRT-PCR Syber Green assays and a triplex of Taqman probes, were extensively validated to establish Retinoid Receptors mRNAs reference values for in vivo normal human bronchial cells, lung tumors and cell lines. Finally, a pan-RAR-beta antibody was generated and extensively validated by western-blot and immunoprecipitation. No promoter-like activity was found for RAR-beta1'. RAR-beta2 mRNAs increase signs the normal differentiation of the human bronchial epithelium while a decrease is observed in most lung cancer cell lines. Accordingly, it is also, along with RXR beta, down-regulated in lung tumors. When using nuclear extracts of BEAS-2B and normal lung cells, only the RAR-beta2 long protein isoform was recognized by our antibody. Rigorous samples processing and extensive biocomputing, were the key factors for this study. mRNA reference values and validated tools can now be used to advance researches on retinoid signalling in the lung

[The receptor theory of atherosclerosis].

Science.gov (United States)

Likhoded, V G; Bondarenko, V M; Gintsburg, A L

2010-01-01

Lipopolysaccharides of Gram-negative bacteria can interact with Toll-like receptor 4 (TLR4) and induce atheroma formation. The risk of atherosclerosis is decreased in case of TLR4 mutation. Other bacterial ligands and endogenous ligands of TLRs can also be involved in induction of atherogenesis. The general concept of atherosclerosis pathogentsis is presented. According to this concept atherogenesis can be initiated by some reactions resulting from interaction of exogenous and endogenous microbial ligands with Toll-like receptors.

An Econometric Validation of Malthusian Theory: Evidence in Nigeria

Directory of Open Access Journals (Sweden)

Musa Abdullahi Sakanko

2018-01-01

Full Text Available Rising population is an asset, provided, the skills of the workforce are used to the maximum extent. If not appropriately channelized, it can be a liability for a nation. A skilled and hardworking population can emerge as a foundation for a country’s development. This study examines the validity of Malthusian Theory in Nigeria using time series data from 1960 to 2016, employs the ARDL bound test techniques. The result shows that in the long-run, population growth and food production move proportionately, while population growth poses a depleting effect on food production in the short-run, thus validating the incidence of Malthusian impact in Nigerian economy in the short-run. The researcher recommended the government should strategize plans, which will further intensify family planning and birth control measure, compulsory western education and revitalization of the agricultural sector.DOI: 10.150408/sjie.v7i1.6461

PIV Measurements for Validation of Self-induction Theory of Vortex Breakdown

Science.gov (United States)

Thompson, Brad; Dabiri, Dana

2005-11-01

THE PROBLEM: Tail buffeting is a severe operational and maintenance problem in twin-tailed aircraft. Tail buffeting is driven by aerodynamic forces resulting from the wing leading edge produced concentrated vortices and their subsequent abrupt breakdown and radial expansion. The expansion leads to large-diameter helical vortices, which impose lateral forces on the tails. Various brute-force, empirical approaches have provided some ad-hoc fixes, but poor understanding of the underlying physics prevents effective design solutions. It is not yet possible to design buffet-free aircraft from first principles. Preliminary work offers a unique explanation for vortex breakdown called the azimuthal vorticity gradient theory ...(Cain 2001). This paper will present and establish experimental evidence using DPIV to validate this recent theory. Cain, C. B. (2001). The Self-Induction Theory of Vortex Breakdown. Aeronautics Dept. Seattle, WA, University of Washington. Master Thesis.

Creation and validation of the barriers to alcohol reduction (BAR) scale using classical test theory and item response theory.

Science.gov (United States)

Kunicki, Zachary J; Schick, Melissa R; Spillane, Nichea S; Harlow, Lisa L

2018-06-01

Those who binge drink are at increased risk for alcohol-related consequences when compared to non-binge drinkers. Research shows individuals may face barriers to reducing their drinking behavior, but few measures exist to assess these barriers. This study created and validated the Barriers to Alcohol Reduction (BAR) scale. Participants were college students ( n  = 230) who endorsed at least one instance of past-month binge drinking (4+ drinks for women or 5+ drinks for men). Using classical test theory, exploratory structural equation modeling found a two-factor structure of personal/psychosocial barriers and perceived program barriers. The sub-factors, and full scale had reasonable internal consistency (i.e., coefficient omega = 0.78 (personal/psychosocial), 0.82 (program barriers), and 0.83 (full measure)). The BAR also showed evidence for convergent validity with the Brief Young Adult Alcohol Consequences Questionnaire ( r  = 0.39, p  Theory (IRT) analysis showed the two factors separately met the unidimensionality assumption, and provided further evidence for severity of the items on the two factors. Results suggest that the BAR measure appears reliable and valid for use in an undergraduate student population of binge drinkers. Future studies may want to re-examine this measure in a more diverse sample.

Development and validation of receptor occupancy pharmacodynamic assays used in the clinical development of the monoclonal antibody vedolizumab.

Science.gov (United States)

Wyant, Tim; Estevam, Jose; Yang, Lili; Rosario, Maria

2016-03-01

Vedolizumab is a monoclonal antibody approved for use in ulcerative colitis and Crohn's disease. By specifically binding to α4 β7 integrin, vedolizumab prevents trafficking of lymphocytes to the gut, thereby interfering with disease pathology. During the clinical development program, the pharmacodynamic effect of vedolizumab was evaluated by 2 flow cytometry receptor occupancy assays: act-1 (ACT-1) and mucosal addressin cell adhesion molecule-1 (MAdCAM-1). Here we describe the development and validation of these assays. The ACT-1 assay is a receptor occupancy free-site assay that uses a monoclonal antibody with the same binding epitope as vedolizumab to detect free (unbound) sites on α4 β7 integrin. The MAdCAM-1 assay used a soluble version of the natural ligand for α4 β7 integrin to detect free sites. The assays were validated using a fit-for-purpose approach throughout the clinical development of vedolizumab. Both the ACT-1 assay and the MAdCAM-1 assay demonstrated acceptable reproducibility and repeatability. The assays were sufficiently stable to allow for clinical use. During clinical testing the assays demonstrated that vedolizumab was able to saturate peripheral cells at all doses tested. Two pharmacodynamic receptor occupancy assays were developed and validated to assess the effect of vedolizumab on peripheral blood cells. The results of these assays demonstrated the practical use of flow cytometry to examine pharmacodynamic response in clinical trials. © 2015 International Clinical Cytometry Society.

The Theory of Planned Behavior (TPB) and Pre-Service Teachers' Technology Acceptance: A Validation Study Using Structural Equation Modeling

Science.gov (United States)

Teo, Timothy; Tan, Lynde

2012-01-01

This study applies the theory of planned behavior (TPB), a theory that is commonly used in commercial settings, to the educational context to explain pre-service teachers' technology acceptance. It is also interested in examining its validity when used for this purpose. It has found evidence that the TPB is a valid model to explain pre-service…

Robust Backlash Estimation for Industrial Drive-Train Systems—Theory and Validation

DEFF Research Database (Denmark)

Papageorgiou, Dimitrios; Blanke, Mogens; Niemann, Hans Henrik

2018-01-01

Backlash compensation is used in modern machinetool controls to ensure high-accuracy positioning. When wear of a machine causes deadzone width to increase, high-accuracy control may be maintained if the deadzone is accurately estimated. Deadzone estimation is also an important parameter to indica......-of-the-art Siemens equipment. The experiments validate the theory and show that expected performance and robustness to parameter uncertainties are both achieved....

The Rorschach texture response: a construct validation study using attachment theory.

Science.gov (United States)

Cassella, Michael J; Viglione, Donald J

2009-11-01

Using attachment theory, in this research, we explored the construct validity of the Rorschach (Exner, 1974) Texture (T) response as a measure of interpersonal closeness and contact. A total of 40 men and 39 women completed the Rorschach and 2 attachment inventories. Their romantic partners also completed an informant version of the attachment measures. Attachment styles were measured by factor scores involving both self-report and partner report. Results indicate that attachment theory, as a broad conceptual framework, is associated with T. Specifically, T = 1 is most closely associated with a secure attachment style, T > 1 with aspects of the preoccupied style, and T = 0 with aspects of the avoidant style and an absence of secure attachment. Needs for closeness and contact associated with T can be couched within an adult attachment theory, but in this study, we did not test for problematic aspects of insecure attachment. Gender is a complicating factor and deserves more study.

Systematic Development and Validation of a Theory-Based Questionnaire to Assess Toddler Feeding12

OpenAIRE

Hurley, Kristen M.; Pepper, M. Reese; Candelaria, Margo; Wang, Yan; Caulfield, Laura E.; Latta, Laura; Hager, Erin R.; Black, Maureen M.

2013-01-01

This paper describes the development and validation of a 27-item caregiver-reported questionnaire on toddler feeding. The development of the Toddler Feeding Behavior Questionnaire was based on a theory of interactive feeding that incorporates caregivers’ responses to concerns about their children’s dietary intake, appetite, size, and behaviors rather than relying exclusively on caregiver actions. Content validity included review by an expert panel (n = 7) and testing in a pilot sample (n = 10...

Using G-Theory to Enhance Evidence of Reliability and Validity for Common Uses of the Paulhus Deception Scales.

Science.gov (United States)

Vispoel, Walter P; Morris, Carrie A; Kilinc, Murat

2018-01-01

We applied a new approach to Generalizability theory (G-theory) involving parallel splits and repeated measures to evaluate common uses of the Paulhus Deception Scales based on polytomous and four types of dichotomous scoring. G-theory indices of reliability and validity accounting for specific-factor, transient, and random-response measurement error supported use of polytomous over dichotomous scores as contamination checks; as control, explanatory, and outcome variables; as aspects of construct validation; and as indexes of environmental effects on socially desirable responding. Polytomous scoring also provided results for flagging faking as dependable as those when using dichotomous scoring methods. These findings argue strongly against the nearly exclusive use of dichotomous scoring for the Paulhus Deception Scales in practice and underscore the value of G-theory in demonstrating this. We provide guidelines for applying our G-theory techniques to other objectively scored clinical assessments, for using G-theory to estimate how changes to a measure might improve reliability, and for obtaining software to conduct G-theory analyses free of charge.

Protocol: validation of the INCODE barometer to measure the innovation compe-tence through the Rasch Measurement Theory

Directory of Open Access Journals (Sweden)

Lidia Sanchez

2017-06-01

Full Text Available This communication presents a protocol in order to show the different phases that must be followed in order to validate the INCODE barometer, which is used to measure the innovation competence, with Rasch Measurement Theory. Five phases are stated: dimensionality analysis, individual reliability and validity analysis of ítems and persons, global reliability and validity analysis, and cathegory analysis.

Assessing Academic Advising Outcomes Using Social Cognitive Theory: A Validity and Reliability Study

Science.gov (United States)

Erlich, Richard J.; Russ-Eft, Darlene F.

2012-01-01

The validity and reliability of three instruments, the "Counselor Rubric for Gauging Student Understanding of Academic Planning," micro-analytic questions, and the "Student Survey for Understanding Academic Planning," all based on social cognitive theory, were tested as means to assess self-efficacy and self-regulated learning in college academic…

Functional Validation of Heteromeric Kainate Receptor Models.

Science.gov (United States)

Paramo, Teresa; Brown, Patricia M G E; Musgaard, Maria; Bowie, Derek; Biggin, Philip C

2017-11-21

Kainate receptors require the presence of external ions for gating. Most work thus far has been performed on homomeric GluK2 but, in vivo, kainate receptors are likely heterotetramers. Agonists bind to the ligand-binding domain (LBD) which is arranged as a dimer of dimers as exemplified in homomeric structures, but no high-resolution structure currently exists of heteromeric kainate receptors. In a full-length heterotetramer, the LBDs could potentially be arranged either as a GluK2 homomer alongside a GluK5 homomer or as two GluK2/K5 heterodimers. We have constructed models of the LBD dimers based on the GluK2 LBD crystal structures and investigated their stability with molecular dynamics simulations. We have then used the models to make predictions about the functional behavior of the full-length GluK2/K5 receptor, which we confirmed via electrophysiological recordings. A key prediction and observation is that lithium ions bind to the dimer interface of GluK2/K5 heteromers and slow their desensitization. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Aromatic interactions impact ligand binding and function at serotonin 5-HT2C G protein-coupled receptors: receptor homology modelling, ligand docking, and molecular dynamics results validated by experimental studies

Science.gov (United States)

Córdova-Sintjago, Tania; Villa, Nancy; Fang, Lijuan; Booth, Raymond G.

2014-02-01

The serotonin (5-hydroxytryptamine, 5-HT) 5-HT2 G protein-coupled receptor (GPCR) family consists of types 2A, 2B, and 2C that share ∼75% transmembrane (TM) sequence identity. Agonists for 5-HT2C receptors are under development for psychoses; whereas, at 5-HT2A receptors, antipsychotic effects are associated with antagonists - in fact, 5-HT2A agonists can cause hallucinations and 5-HT2B agonists cause cardiotoxicity. It is known that 5-HT2A TM6 residues W6.48, F6.51, and F6.52 impact ligand binding and function; however, ligand interactions with these residues at the 5-HT2C receptor have not been reported. To predict and validate molecular determinants for 5-HT2C-specific activation, results from receptor homology modelling, ligand docking, and molecular dynamics simulation studies were compared with experimental results for ligand binding and function at wild type and W6.48A, F6.51A, and F6.52A point-mutated 5-HT2C receptors.

Validation of a Theory of Planned Behavior-Based Questionnaire to Examine Factors Associated With Milk Expression.

Science.gov (United States)

Bai, Yeon K; Dinour, Lauren M

2017-11-01

A proper assessment of multidimensional needs for breastfeeding mothers in various settings is crucial to facilitate and support breastfeeding and its exclusivity. The theory of planned behavior (TPB) has been used frequently to measure factors associated with breastfeeding. Full utility of the TPB requires accurate measurement of theory constructs. Research aim: This study aimed to develop and confirm the psychometric properties of an instrument, Milk Expression on Campus, based on the TPB and to establish the reliability and validity of the instrument. In spring 2015, 218 breastfeeding (current or in the recent past) employees and students at one university campus in northern New Jersey completed the online questionnaire containing demography and theory-based items. Internal consistency (α) and split-half reliability ( r) tests and factor analyses established and confirmed the reliability and construct validity of this instrument. Milk Expression on Campus showed strong and significant reliabilities as a full scale (α = .78, r = .74, p theory construct subscales. Validity was confirmed as psychometric properties corresponded to the factors extracted from the scale. Four factors extracted from the direct construct subscales accounted for 79.49% of the total variability. Four distinct factors from the indirect construct subscales accounted for 73.68% of the total variability. Milk Expression on Campus can serve as a model TPB-based instrument to examine factors associated with women's milk expression behavior. The utility of this instrument extends to designing effective promotion programs to foster breastfeeding and milk expression behaviors in diverse settings.

A fundamental special-relativistic theory valid for all real-valued speeds

Directory of Open Access Journals (Sweden)

Vedprakash Sewjathan

1984-01-01

Full Text Available This paper constitutes a fundamental rederivation of special relativity based on the c-invariance postulate but independent of the assumption ds′2=±ds2 (Einstein [1], Kittel et al [2], Recami [3], the equivalence principle, homogeneity of space-time, isotropy of space, group properties and linearity of space-time transformations or the coincidence of the origins of inertial space-time frames. The mathematical formalism is simpler than Einstein's [4] and Recami's [3]. Whilst Einstein's subluminal and Recami's superluminal theories are rederived in this paper by further assuming the equivalence principle and “mathematical inverses” [4,3], this paper derives (independent of these assumptions with physico-mathematical motivation an alternate singularity-free special-relativistic theory which replaces Einstein's factor [1/(1−V2/c2]12 and Recami's extended-relativistic factor [1/(V2/c2−1]12 by [(1−(V2/c2n/(1−V2/c2]12, where n equals the value of (m(V/m02 as |V|→c. In this theory both Newton's and Einstein's subluminal theories are experimentally valid on account of negligible terms. This theory implies that non-zero rest mass luxons will not be detected as ordinary non-zero rest mass bradyons because of spatial collapse, and non-zero rest mass tachyons are undetectable because they exist in another cosmos, resulting in a supercosmos of matter, with the possibility of infinitely many such supercosmoses, all moving forward in time. Furthermore this theory is not based on any assumption giving rise to the twin paradox controversy. The paper concludes with a discussion of the implications of this theory for general relativity.

Bringing loyalty to e-Health: theory validation using three internet-delivered interventions.

Science.gov (United States)

Crutzen, Rik; Cyr, Dianne; de Vries, Nanne K

2011-09-24

Internet-delivered interventions can effectively change health risk behaviors, but the actual use of these interventions by the target group once they access the website is often very low (high attrition, low adherence). Therefore, it is relevant and necessary to focus on factors related to use of an intervention once people arrive at the intervention website. We focused on user perceptions resulting in e-loyalty (ie, intention to visit an intervention again and to recommend it to others). A background theory for e-loyalty, however, is still lacking for Internet-delivered interventions. The objective of our study was to propose and validate a conceptual model regarding user perceptions and e-loyalty within the field of eHealth. We presented at random 3 primary prevention interventions aimed at the general public and, subsequently, participants completed validated measures regarding user perceptions and e-loyalty. Time on each intervention website was assessed by means of server registrations. Of the 592 people who were invited to participate, 397 initiated the study (response rate: 67%) and 351 (48% female, mean age 43 years, varying in educational level) finished the study (retention rate: 88%). Internal consistency of all measures was high (Cronbach alpha > .87). The findings demonstrate that the user perceptions regarding effectiveness (beta(range) .21-.41) and enjoyment (beta(range) .14-.24) both had a positive effect on e-loyalty, which was mediated by active trust (beta(range) .27-.60). User perceptions and e-loyalty had low correlations with time on the website (r(range) .04-.18). The consistent pattern of findings speaks in favor of their robustness and contributes to theory validation regarding e-loyalty. The importance of a theory-driven solution to a practice-based problem (ie, low actual use) needs to be stressed in view of the importance of the Internet in terms of intervention development. Longitudinal studies are needed to investigate whether people

Validation of experimental molecular crystal structures with dispersion-corrected density functional theory calculations

International Nuclear Information System (INIS)

Streek, Jacco van de; Neumann, Marcus A.

2010-01-01

The accuracy of a dispersion-corrected density functional theory method is validated against 241 experimental organic crystal structures from Acta Cryst. Section E. This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 Å (0.084 Å for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 Å either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect

Academic Self-Esteem and Perceived Validity of Grades: A Test of Self-Verification Theory.

Science.gov (United States)

Okun, Morris A.; Fournet, Lee M.

1993-01-01

The hypothesis derived from self-verification theory that semester grade point average would be positively related to perceived validity of grade scores among high self-esteem undergraduates and inversely related for low self-esteem students was not supported in a study with 281 undergraduates. (SLD)

Neuroscience, virtual reality and neurorehabilitation: brain repair as a validation of brain theory.

Science.gov (United States)

Verschure, Paul F M J

2011-01-01

This paper argues that basing cybertherapy approaches on a theoretical understanding of the brain has advantages. On one hand it provides for a rational approach towards therapy design while on the other allowing for a direct validation of brain theory in the clinic. As an example this paper discusses how the Distributed Adaptive Control architecture, a theory of mind, brain and action, has given rise to a new paradigm in neurorehabilitation called the Rehabilitation Gaming System (RGS) and to novel neuroprosthetic systems. The neuroprosthetic system considered is developed to replace the function of cerebellar micro-circuits, expresses core aspects of the learning systems of DAC and has been successfully tested in in-vivo experiments. The Virtual reality based rehabilitation paradigm of RGS has been validated in the treatment of acute and chronic stroke and has been shown to be more effective than existing methods. RGS provides a foundation for integrated at-home therapy systems that can operate largely autonomously when also augmented with appropriate physiological monitoring and diagnostic devices. These examples provide first steps towards a science based medicine.

Development and psychometric validation of social cognitive theory scales in an oral health context.

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Jones, Kelly; Parker, Eleanor J; Steffens, Margaret A; Logan, Richard M; Brennan, David; Jamieson, Lisa M

2016-04-01

This study aimed to develop and evaluate scales reflecting potentially modifiable social cognitive theory-based risk indicators associated with homeless populations' oral health. The scales are referred to as the social cognitive theory risk scales in an oral health context (SCTOH) and are referred to as SCTOH(SE), SCTOH(K) and SCTOH(F), respectively. The three SCTOH scales assess the key constructs of social cognitive theory: self-efficacy, knowledge and fatalism. The reliability and validity of the three scales were evaluated in a convenience sample of 248 homeless participants (age range 17-78 years, 79% male) located in a metropolitan setting in Australia. The scales were supported by exploratory factor analysis and established three distinct and internally consistent domains of social cognition: oral health-related self-efficacy, oral health-related knowledge and oral health-related fatalism, with Cronbach's alphas of 0.95, 0.85 and Spearman's-Brown ρ of 0.69. Concurrent ability was confirmed by each SCTOH scale's association with oral health status in the expected directions. The three SCTOH scales appear to be internally valid and reliable. If confirmed by further research, these scales could potentially be used for tailored educational and cognitive-behavioural interventions to reduce oral health inequalities among homeless and other vulnerable populations. © 2015 Public Health Association of Australia.

Measuring Constructs in Family Science: How Can Item Response Theory Improve Precision and Validity?

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Gordon, Rachel A.

2015-01-01

This article provides family scientists with an understanding of contemporary measurement perspectives and the ways in which item response theory (IRT) can be used to develop measures with desired evidence of precision and validity for research uses. The article offers a nontechnical introduction to some key features of IRT, including its…

Validation of Sustainable Development Practices Scale Using the Bayesian Approach to Item Response Theory

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Martin Hernani Merino

2014-12-01

Full Text Available There has been growing recognition of the importance of creating performance measurement tools for the economic, social and environmental management of micro and small enterprise (MSE. In this context, this study aims to validate an instrument to assess perceptions of sustainable development practices by MSEs by means of a Graded Response Model (GRM with a Bayesian approach to Item Response Theory (IRT. The results based on a sample of 506 university students in Peru, suggest that a valid measurement instrument was achieved. At the end of the paper, methodological and managerial contributions are presented.

Current Concerns in Validity Theory.

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Kane, Michael

Validity is concerned with the clarification and justification of the intended interpretations and uses of observed scores. It has not been easy to formulate a general methodology set of principles for validation, but progress has been made, especially as the field has moved from relatively limited criterion-related models to sophisticated…

Experimental design optimisation: theory and application to estimation of receptor model parameters using dynamic positron emission tomography

International Nuclear Information System (INIS)

Delforge, J.; Syrota, A.; Mazoyer, B.M.

1989-01-01

General framework and various criteria for experimental design optimisation are presented. The methodology is applied to estimation of receptor-ligand reaction model parameters with dynamic positron emission tomography data. The possibility of improving parameter estimation using a new experimental design combining an injection of the β + -labelled ligand and an injection of the cold ligand is investigated. Numerical simulations predict remarkable improvement in the accuracy of parameter estimates with this new experimental design and particularly the possibility of separate estimations of the association constant (k +1 ) and of receptor density (B' max ) in a single experiment. Simulation predictions are validated using experimental PET data in which parameter uncertainties are reduced by factors ranging from 17 to 1000. (author)

Discriminant content validity: a quantitative methodology for assessing content of theory-based measures, with illustrative applications.

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Johnston, Marie; Dixon, Diane; Hart, Jo; Glidewell, Liz; Schröder, Carin; Pollard, Beth

2014-05-01

In studies involving theoretical constructs, it is important that measures have good content validity and that there is not contamination of measures by content from other constructs. While reliability and construct validity are routinely reported, to date, there has not been a satisfactory, transparent, and systematic method of assessing and reporting content validity. In this paper, we describe a methodology of discriminant content validity (DCV) and illustrate its application in three studies. Discriminant content validity involves six steps: construct definition, item selection, judge identification, judgement format, single-sample test of content validity, and assessment of discriminant items. In three studies, these steps were applied to a measure of illness perceptions (IPQ-R) and control cognitions. The IPQ-R performed well with most items being purely related to their target construct, although timeline and consequences had small problems. By contrast, the study of control cognitions identified problems in measuring constructs independently. In the final study, direct estimation response formats for theory of planned behaviour constructs were found to have as good DCV as Likert format. The DCV method allowed quantitative assessment of each item and can therefore inform the content validity of the measures assessed. The methods can be applied to assess content validity before or after collecting data to select the appropriate items to measure theoretical constructs. Further, the data reported for each item in Appendix S1 can be used in item or measure selection. Statement of contribution What is already known on this subject? There are agreed methods of assessing and reporting construct validity of measures of theoretical constructs, but not their content validity. Content validity is rarely reported in a systematic and transparent manner. What does this study add? The paper proposes discriminant content validity (DCV), a systematic and transparent method

Grid inhomogeneous solvation theory: hydration structure and thermodynamics of the miniature receptor cucurbit[7]uril.

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Nguyen, Crystal N; Young, Tom Kurtzman; Gilson, Michael K

2012-07-28

The displacement of perturbed water upon binding is believed to play a critical role in the thermodynamics of biomolecular recognition, but it is nontrivial to unambiguously define and answer questions about this process. We address this issue by introducing grid inhomogeneous solvation theory (GIST), which discretizes the equations of inhomogeneous solvation theory (IST) onto a three-dimensional grid situated in the region of interest around a solute molecule or complex. Snapshots from explicit solvent simulations are used to estimate localized solvation entropies, energies, and free energies associated with the grid boxes, or voxels, and properly summing these thermodynamic quantities over voxels yields information about hydration thermodynamics. GIST thus provides a smoothly varying representation of water properties as a function of position, rather than focusing on hydration sites where solvent is present at high density. It therefore accounts for full or partial displacement of water from sites that are highly occupied by water, as well as for partly occupied and water-depleted regions around the solute. GIST can also provide a well-defined estimate of the solvation free energy and therefore enables a rigorous end-states analysis of binding. For example, one may not only use a first GIST calculation to project the thermodynamic consequences of displacing water from the surface of a receptor by a ligand, but also account, in a second GIST calculation, for the thermodynamics of subsequent solvent reorganization around the bound complex. In the present study, a first GIST analysis of the molecular host cucurbit[7]uril is found to yield a rich picture of hydration structure and thermodynamics in and around this miniature receptor. One of the most striking results is the observation of a toroidal region of high water density at the center of the host's nonpolar cavity. Despite its high density, the water in this toroidal region is disfavored energetically and

Deflation-activated receptors, not classical inflation-activated receptors, mediate the Hering-Breuer deflation reflex.

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Yu, Jerry

2016-11-01

Many airway sensory units respond to both lung inflation and deflation. Whether those responses to opposite stimuli come from one sensor (one-sensor theory) or more than one sensor (multiple-sensor theory) is debatable. One-sensor theory is commonly presumed in the literature. This article proposes a multiple-sensor theory in which a sensory unit contains different sensors for sensing different forces. Two major types of mechanical sensors operate in the lung: inflation- and deflation-activated receptors (DARs). Inflation-activated sensors can be further divided into slowly adapting receptors (SARs) and rapidly adapting receptors (RARs). Many SAR and RAR units also respond to lung deflation because they contain DARs. Pure DARs, which respond to lung deflation only, are rare in large animals but are easily identified in small animals. Lung deflation-induced reflex effects previously attributed to RARs should be assigned to DARs (including pure DARs and DARs associated with SARs and RARs) if the multiple-sensor theory is accepted. Thus, based on the information, it is proposed that activation of DARs can attenuate lung deflation, shorten expiratory time, increase respiratory rate, evoke inspiration, and cause airway secretion and dyspnea.

Development and Validation of an Instrument Measuring Theory-Based Determinants of Monitoring Obesogenic Behaviors of Pre-Schoolers among Hispanic Mothers

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Paul Branscum

2016-06-01

Full Text Available Public health interventions are greatly needed for obesity prevention, and planning for such strategies should include community participation. The study’s purpose was to develop and validate a theory-based instrument with low-income, Hispanic mothers of preschoolers, to assess theory-based determinants of maternal monitoring of child’s consumption of fruits and vegetables and sugar-sweetened beverages (SSB. Nine focus groups with mothers were conducted to determine nutrition-related behaviors that mothers found as most obesogenic for their children. Next, behaviors were operationally defined and rated for importance and changeability. Two behaviors were selected for investigation (fruits and vegetable and SSB. Twenty semi-structured interviews with mothers were conducted next to develop culturally appropriate items for the instrument. Afterwards, face and content validity were established using a panel of six experts. Finally, the instrument was tested with a sample of 238 mothers. Psychometric properties evaluated included construct validity (using the maximum likelihood extraction method of factor analysis, and internal consistency reliability (Cronbach’s alpha. Results suggested that all scales on the instrument were valid and reliable, except for the autonomy scales. Researchers and community planners working with Hispanic families can use this instrument to measure theory-based determinants of parenting behaviors related to preschoolers’ consumption of fruits and vegetables, and SSB.

Validity and reliability analysis of the planned behavior theory scale related to the testicular self-examination in a Turkish context.

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Iyigun, Emine; Tastan, Sevinc; Ayhan, Hatice; Kose, Gulsah; Acikel, Cengizhan

2016-06-01

This study aimed to determine the validity and reliability levels of the Planned Behavior Theory Scale as related to a testicular self-examination. The study was carried out in a health-profession higher-education school in Ankara, Turkey, from April to June 2012. The study participants comprised 215 male students. Study data were collected by using a questionnaire, a planned behavior theory scale related to testicular self-examination, and Champion's Health Belief Model Scale (CHBMS). The sub-dimensions of the planned behavior theory scale, namely those of intention, attitude, subjective norms and self-efficacy, were found to have Cronbach's alpha values of between 0.81 and 0.89. Exploratory factor analysis showed that items of the scale had five factors that accounted for 75% of the variance. Of these, the sub-dimension of intention was found to have the highest level of contribution. A significant correlation was found between the sub-dimensions of the testicular self-examination planned behavior theory scale and those of CHBMS (p Planned Behavior Theory Scale is a valid and reliable measurement for Turkish society.

Preliminary Process Theory does not validate the Comparison Question Test: A comment on Palmatier and Rovner

NARCIS (Netherlands)

Ben-Shakar, G.; Gamer, M.; Iacono, W.; Meijer, E.; Verschuere, B.

2015-01-01

Palmatier and Rovner (2015) attempt to establish the construct validity of the Comparison Question Test (CQT) by citing extensive research ranging from modern neuroscience to memory and psychophysiology. In this comment we argue that merely citing studies on the preliminary process theory (PPT) of

An Evaluation of the Cross-Cultural Validity of Holland's Theory: Career Choices by Workers in India.

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Leong, Frederick T. L.; Austin, James T.; Sekaran, Uma; Komarraju, Meera

1998-01-01

Natives of India (n=172) completed Holland's Vocational Preference Inventory and job satisfaction measures. The inventory did not exhibit high external validity with this population. Congruence, consistency, and differentiation did not predict job or occupational satisfaction, suggesting cross-cultural limits on Holland's theory. (SK)

Validity and Reliability of Published Comprehensive Theory of Mind Tests for Normal Preschool Children: A Systematic Review

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Seyyede Zohreh Ziatabar Ahmadi

2015-12-01

Full Text Available Objective: Theory of mind (ToM or mindreading is an aspect of social cognition that evaluates mental states and beliefs of oneself and others. Validity and reliability are very important criteria when evaluating standard tests; and without them, these tests are not usable. The aim of this study was to systematically review the validity and reliability of published English comprehensive ToM tests developed for normal preschool children.Method: We searched MEDLINE (PubMed interface, Web of Science, Science direct, PsycINFO, and also evidence base Medicine (The Cochrane Library databases from 1990 to June 2015. Search strategy was Latin transcription of ‘Theory of Mind’ AND test AND children. Also, we manually studied the reference lists of all final searched articles and carried out a search of their references. Inclusion criteria were as follows: Valid and reliable diagnostic ToM tests published from 1990 to June 2015 for normal preschool children; and exclusion criteria were as follows: the studies that only used ToM tests and single tasks (false belief tasks for ToM assessment and/or had no description about structure, validity or reliability of their tests. Methodological quality of the selected articles was assessed using the Critical Appraisal Skills Programme (CASP.Result: In primary searching, we found 1237 articles in total databases. After removing duplicates and applying all inclusion and exclusion criteria, we selected 11 tests for this systematic review. Conclusion: There were a few valid, reliable and comprehensive ToM tests for normal preschool children. However, we had limitations concerning the included articles. The defined ToM tests were different in populations, tasks, mode of presentations, scoring, mode of responses, times and other variables. Also, they had various validities and reliabilities. Therefore, it is recommended that the researchers and clinicians select the ToM tests according to their psychometric

A pilot study to validate measures of the theory of reasoned action for organ donation behavior.

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Wong, Shui Hung; Chow, Amy Yin Man

2018-04-01

The present study aimed at taking the first attempt in validating the measures generated based on the theory of reasoned action (TRA). A total of 211 university students participated in the study, 95 were included in the exploratory factor analysis and 116 were included in the confirmatory factor analysis. The TRA measurements were established with adequate psychometric properties, internal consistency, and construct validity. Findings also suggested that attitude toward organ donation has both a cognitive and affective nature, while the subjective norm of the family seems to be important to students' views on organ donation.

The validity and scalability of the Theory of Mind Scale with toddlers and preschoolers.

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Hiller, Rachel M; Weber, Nathan; Young, Robyn L

2014-12-01

Despite the importance of theory of mind (ToM) for typical development, there remain 2 key issues affecting our ability to draw robust conclusions. One is the continued focus on false belief as the sole measure of ToM. The second is the lack of empirically validated measures of ToM as a broad construct. Our key aim was to examine the validity and reliability of the 5-item ToM scale (Peterson, Wellman, & Liu, 2005). In particular, we extended on previous research of this scale by assessing its scalability and validity for use with children from 2 years of age. Sixty-eight typically developing children (aged 24 to 61 months) were assessed on the scale's 5 tasks, along with a sixth Sally-Anne false-belief task. Our data replicated the scalability of the 5 tasks for a Rasch-but not Guttman-scale. Guttman analysis showed that a 4-item scale may be more suitable for this age range. Further, the tasks showed good internal consistency and validity for use with children as young as 2 years of age. Overall, the measure provides a valid and reliable tool for the assessment of ToM, and in particular, the longitudinal assessment of this ability as a construct. (c) 2014 APA, all rights reserved.

Transverse signal decay under the weak field approximation: Theory and validation.

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Berman, Avery J L; Pike, G Bruce

2018-07-01

To derive an expression for the transverse signal time course from systems in the motional narrowing regime, such as water diffusing in blood. This was validated in silico and experimentally with ex vivo blood samples. A closed-form solution (CFS) for transverse signal decay under any train of refocusing pulses was derived using the weak field approximation. The CFS was validated via simulations of water molecules diffusing in the presence of spherical perturbers, with a range of sizes and under various pulse sequences. The CFS was compared with more conventional fits assuming monoexponential decay, including chemical exchange, using ex vivo blood Carr-Purcell-Meiboom-Gill data. From simulations, the CFS was shown to be valid in the motional narrowing regime and partially into the intermediate dephasing regime, with increased accuracy with increasing Carr-Purcell-Meiboom-Gill refocusing rate. In theoretical calculations of the CFS, fitting for the transverse relaxation rate (R 2 ) gave excellent agreement with the weak field approximation expression for R 2 for Carr-Purcell-Meiboom-Gill sequences, but diverged for free induction decay. These same results were confirmed in the ex vivo analysis. Transverse signal decay in the motional narrowing regime can be accurately described analytically. This theory has applications in areas such as tissue iron imaging, relaxometry of blood, and contrast agent imaging. Magn Reson Med 80:341-350, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Development and validation of the irritable bowel syndrome scale under the system of quality of life instruments for chronic diseases QLICD-IBS: combinations of classical test theory and generalizability theory.

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Lei, Pingguang; Lei, Guanghe; Tian, Jianjun; Zhou, Zengfen; Zhao, Miao; Wan, Chonghua

2014-10-01

This paper is aimed to develop the irritable bowel syndrome (IBS) scale of the system of Quality of Life Instruments for Chronic Diseases (QLICD-IBS) by the modular approach and validate it by both classical test theory and generalizability theory. The QLICD-IBS was developed based on programmed decision procedures with multiple nominal and focus group discussions, in-depth interview, and quantitative statistical procedures. One hundred twelve inpatients with IBS were used to provide the data measuring QOL three times before and after treatments. The psychometric properties of the scale were evaluated with respect to validity, reliability, and responsiveness employing correlation analysis, factor analyses, multi-trait scaling analysis, t tests and also G studies and D studies of generalizability theory analysis. Multi-trait scaling analysis, correlation, and factor analyses confirmed good construct validity and criterion-related validity when using SF-36 as a criterion. Test-retest reliability coefficients (Pearson r and intra-class correlation (ICC)) for the overall score and all domains were higher than 0.80; the internal consistency α for all domains at two measurements were higher than 0.70 except for the social domain (0.55 and 0.67, respectively). The overall score and scores for all domains/facets had statistically significant changes after treatments with moderate or higher effect size standardized response mean (SRM) ranging from 0.72 to 1.02 at domain levels. G coefficients and index of dependability (Ф coefficients) confirmed the reliability of the scale further with more exact variance components. The QLICD-IBS has good validity, reliability, responsiveness, and some highlights and can be used as the quality of life instrument for patients with IBS.

Methodical Challenges and a Possible Resolution in the Assessment of Receptor Reserve for Adenosine, an Agonist with Short Half-Life

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Judit Zsuga

2017-05-01

Full Text Available The term receptor reserve, first introduced and used in the traditional receptor theory, is an integrative measure of response-inducing ability of the interaction between an agonist and a receptor system (consisting of a receptor and its downstream signaling. The underlying phenomenon, i.e., stimulation of a submaximal fraction of receptors can apparently elicit the maximal effect (in certain cases, provides an opportunity to assess the receptor reserve. However, determining receptor reserve is challenging for agonists with short half-lives, such as adenosine. Although adenosine metabolism can be inhibited several ways (in order to prevent the rapid elimination of adenosine administered to construct concentration–effect (E/c curves for the determination, the consequent accumulation of endogenous adenosine biases the results. To address this problem, we previously proposed a method, by means of which this bias can be mathematically corrected (utilizing a traditional receptor theory-independent approach. In the present investigation, we have offered in silico validation of this method by simulating E/c curves with the use of the operational model of agonism and then by evaluating them using our method. We have found that our method is suitable to reliably assess the receptor reserve for adenosine in our recently published experimental setting, suggesting that it may be capable for a qualitative determination of receptor reserve for rapidly eliminating agonists in general. In addition, we have disclosed a possible interference between FSCPX (8-cyclopentyl-N3-[3-(4-(fluorosulfonylbenzoyloxypropyl]-N1-propylxanthine, an irreversible A1 adenosine receptor antagonist, and NBTI (S-(2-hydroxy-5-nitrobenzyl-6-thioinosine, a nucleoside transport inhibitor, i.e., FSCPX may blunt the effect of NBTI.

DO TANZANIAN COMPANIES PRACTICE PECKING ORDER THEORY, AGENCY COST THEORY OR TRADE-OFF THEORY? AN EMPIRICAL STUDY IN TANZANIAN LISTED COMPANIES

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Ntogwa Ng'habi Bundala

2012-01-01

Full Text Available The empirical study was focused predominantly on validity tests of the three theories on capital structures, the static trade-off theory, the pecking order theory (information asymmetry theory, and agency cost theory in the Tanzanian context. The study used secondary data from eight of the non-financial companies listed in Dar Es Salaam Stock Exchange (DSE from 2006-2012. The study used descriptive (quantitative approach to test the practicality of the theories in Tanzania. The multiple regressions model used to test the theoretical relationship between the financial leverage and characteristics of the company. The research found that there is no strong evidence for validation of static trade off theory, little support of pecking order theory, but the agency cost theory is confirmed to be valid and practiced in Tanzania. It recommended that Tanzanian companies should be adhering to the determinants of the capital structure in the Tanzanian context found by this study.

Complete relaxation and conformational exchange matrix (CORCEMA) analysis of intermolecular saturation transfer effects in reversibly forming ligand-receptor complexes.

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Jayalakshmi, V; Krishna, N Rama

2002-03-01

A couple of recent applications of intermolecular NOE (INOE) experiments as applied to biomolecular systems involve the (i) saturation transfer difference NMR (STD-NMR) method and (ii) the intermolecular cross-saturation NMR (ICS-NMR) experiment. STD-NMR is a promising tool for rapid screening of a large library of compounds to identify bioactive ligands binding to a target protein. Additionally, it is also useful in mapping the binding epitopes presented by a bioactive ligand to its target protein. In this latter application, the STD-NMR technique is essentially similar to the ICS-NMR experiment, which is used to map protein-protein or protein-nucleic acid contact surfaces in complexes. In this work, we present a complete relaxation and conformational exchange matrix (CORCEMA) theory (H. N. B. Moseley et al., J. Magn. Reson. B 108, 243-261 (1995)) applicable for these two closely related experiments. As in our previous work, we show that when exchange is fast on the relaxation rate scale, a simplified CORCEMA theory can be formulated using a generalized average relaxation rate matrix. Its range of validity is established by comparing its predictions with those of the exact CORCEMA theory which is valid for all exchange rates. Using some ideal model systems we have analyzed the factors that influence the ligand proton intensity changes when the resonances from some protons on the receptor protein are saturated. The results show that the intensity changes in the ligand signals in an intermolecular NOE experiment are very much dependent upon: (1) the saturation time, (2) the location of the saturated receptor protons with respect to the ligand protons, (3) the conformation of the ligand-receptor interface, (4) the rotational correlation times for the molecular species, (5) the kinetics of the reversibly forming complex, and (6) the ligand/receptor ratio. As an example of a typical application of the STD-NMR experiment we have also simulated the STD effects for a

Gene-environment interaction between the oxytocin receptor (OXTR) gene and parenting behaviour on children's theory of mind.

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Wade, Mark; Hoffmann, Thomas J; Jenkins, Jennifer M

2015-12-01

Theory of mind (ToM) is the ability to interpret and understand human behaviour by representing the mental states of others. Like many human capacities, ToM is thought to develop through both complex biological and socialization mechanisms. However, no study has examined the joint effect of genetic and environmental influences on ToM. This study examined how variability in the oxytocin receptor gene (OXTR) and parenting behavior--two widely studied factors in ToM development-interacted to predict ToM in pre-school-aged children. Participants were 301 children who were part of an ongoing longitudinal birth cohort study. ToM was assessed at age 4.5 using a previously validated scale. Parenting was assessed through observations of mothers' cognitively sensitive behaviours. Using a family-based association design, it was suggestive that a particular variant (rs11131149) interacted with maternal cognitive sensitivity on children's ToM (P = 0.019). More copies of the major allele were associated with higher ToM as a function of increasing cognitive sensitivity. A sizeable 26% of the variability in ToM was accounted for by this interaction. This study provides the first empirical evidence of gene-environment interactions on ToM, supporting the notion that genetic factors may be modulated by potent environmental influences early in development. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Design, synthesis, and validation of a β-turn mimetic library targeting protein-protein and peptide-receptor interactions.

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Whitby, Landon R; Ando, Yoshio; Setola, Vincent; Vogt, Peter K; Roth, Bryan L; Boger, Dale L

2011-07-06

The design and synthesis of a β-turn mimetic library as a key component of a small-molecule library targeting the major recognition motifs involved in protein-protein interactions is described. Analysis of a geometric characterization of 10,245 β-turns in the protein data bank (PDB) suggested that trans-pyrrolidine-3,4-dicarboxamide could serve as an effective and synthetically accessible library template. This was confirmed by initially screening select compounds against a series of peptide-activated GPCRs that recognize a β-turn structure in their endogenous ligands. This validation study was highlighted by identification of both nonbasic and basic small molecules with high affinities (K(i) = 390 and 23 nM, respectively) for the κ-opioid receptor (KOR). Consistent with the screening capabilities of collaborators and following the design validation, the complete library was assembled as 210 mixtures of 20 compounds, providing a total of 4200 compounds designed to mimic all possible permutations of 3 of the 4 residues in a naturally occurring β-turn. Unique to the design and because of the C(2) symmetry of the template, a typical 20 × 20 × 20-mix (8000 compounds prepared as 400 mixtures of 20 compounds) needed to represent 20 variations in the side chains of three amino acid residues reduces to a 210 × 20-mix, thereby simplifying the library synthesis and subsequent screening. The library was prepared using a solution-phase synthetic protocol with liquid-liquid or liquid-solid extractions for purification and conducted on a scale that insures its long-term availability for screening campaigns. Screening the library against the human opioid receptors (KOR, MOR, and DOR) identified not only the activity of library members expected to mimic the opioid receptor peptide ligands but also additional side-chain combinations that provided enhanced receptor binding selectivities (>100-fold) and affinities (as low as K(i) = 80 nM for KOR). A key insight to emerge from

Development and validation of the coronary heart disease scale under the system of quality of life instruments for chronic diseases QLICD-CHD: combinations of classical test theory and Generalizability Theory.

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Wan, Chonghua; Li, Hezhan; Fan, Xuejin; Yang, Ruixue; Pan, Jiahua; Chen, Wenru; Zhao, Rong

2014-06-04

Quality of life (QOL) for patients with coronary heart disease (CHD) is now concerned worldwide with the specific instruments being seldom and no one developed by the modular approach. This paper is aimed to develop the CHD scale of the system of Quality of Life Instruments for Chronic Diseases (QLICD-CHD) by the modular approach and validate it by both classical test theory and Generalizability Theory. The QLICD-CHD was developed based on programmed decision procedures with multiple nominal and focus group discussions, in-depth interview, pre-testing and quantitative statistical procedures. 146 inpatients with CHD were used to provide the data measuring QOL three times before and after treatments. The psychometric properties of the scale were evaluated with respect to validity, reliability and responsiveness employing correlation analysis, factor analyses, multi-trait scaling analysis, t-tests and also G studies and D studies of Genralizability Theory analysis. Multi-trait scaling analysis, correlation and factor analyses confirmed good construct validity and criterion-related validity when using SF-36 as a criterion. The internal consistency α and test-retest reliability coefficients (Pearson r and Intra-class correlations ICC) for the overall instrument and all domains were higher than 0.70 and 0.80 respectively; The overall and all domains except for social domain had statistically significant changes after treatments with moderate effect size SRM (standardized response mea) ranging from 0.32 to 0.67. G-coefficients and index of dependability (Ф coefficients) confirmed the reliability of the scale further with more exact variance components. The QLICD-CHD has good validity, reliability, and moderate responsiveness and some highlights, and can be used as the quality of life instrument for patients with CHD. However, in order to obtain better reliability, the numbers of items for social domain should be increased or the items' quality, not quantity, should be

Development and validation of the nasopharyngeal cancer scale among the system of quality of life instruments for cancer patients (QLICP-NA V2.0): combined classical test theory and generalizability theory.

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Wu, Jiayuan; Hu, Liren; Zhang, Gaohua; Liang, Qilian; Meng, Qiong; Wan, Chonghua

2016-08-01

This research was designed to develop a nasopharyngeal cancer (NPC) scale based on quality of life (QOL) instruments for cancer patients (QLICP-NA). This scale was developed by using a modular approach and was evaluated by classical test and generalizability theories. Programmed decision procedures and theories on instrument development were applied to create QLICP-NA V2.0. A total of 121 NPC inpatients were assessed using QLICP-NA V2.0 to measure their QOL data from hospital admission until discharge. Scale validity, reliability, and responsiveness were evaluated by correlation, factor, parallel, multi-trait scaling, and t test analyses, as well as by generalizability (G) and decision (D) studies of the generalizability theory. Results of multi-trait scaling, correlation, factor, and parallel analyses indicated that QLICP-NA V2.0 exhibited good construct validity. The significant difference of QOL between the treated and untreated NPC patients indicated a good clinical validity of the questionnaire. The internal consistency (α) and test-retest reliability coefficients (intra-class correlations) of each domain, as well as the overall scale, were all >0.70. Ceiling effects were not found in all domains and most facets, except for common side effects (24.8 %) in the domain of common symptoms and side effects, tumor early symptoms (27.3 %) and therapeutic side effects (23.2 %) in specific domain, whereas floor effects did not exist in each domain/facet. The overall changes in the physical and social domains were significantly different between pre- and post-treatments with a moderate effective size (standard response mean) ranging from 0.21 to 0.27 (p theory. QLICP-NA V2.0 exhibited reasonable degrees of validity, reliability, and responsiveness. However, this scale must be further improved before it can be used as a practical instrument to evaluate the QOL of NPC patients in China.

Implausibility of the vibrational theory of olfaction.

Science.gov (United States)

Block, Eric; Jang, Seogjoo; Matsunami, Hiroaki; Sekharan, Sivakumar; Dethier, Bérénice; Ertem, Mehmed Z; Gundala, Sivaji; Pan, Yi; Li, Shengju; Li, Zhen; Lodge, Stephene N; Ozbil, Mehmet; Jiang, Huihong; Penalba, Sonia F; Batista, Victor S; Zhuang, Hanyi

2015-05-26

The vibrational theory of olfaction assumes that electron transfer occurs across odorants at the active sites of odorant receptors (ORs), serving as a sensitive measure of odorant vibrational frequencies, ultimately leading to olfactory perception. A previous study reported that human subjects differentiated hydrogen/deuterium isotopomers (isomers with isotopic atoms) of the musk compound cyclopentadecanone as evidence supporting the theory. Here, we find no evidence for such differentiation at the molecular level. In fact, we find that the human musk-recognizing receptor, OR5AN1, identified using a heterologous OR expression system and robustly responding to cyclopentadecanone and muscone, fails to distinguish isotopomers of these compounds in vitro. Furthermore, the mouse (methylthio)methanethiol-recognizing receptor, MOR244-3, as well as other selected human and mouse ORs, responded similarly to normal, deuterated, and (13)C isotopomers of their respective ligands, paralleling our results with the musk receptor OR5AN1. These findings suggest that the proposed vibration theory does not apply to the human musk receptor OR5AN1, mouse thiol receptor MOR244-3, or other ORs examined. Also, contrary to the vibration theory predictions, muscone-d30 lacks the 1,380- to 1,550-cm(-1) IR bands claimed to be essential for musk odor. Furthermore, our theoretical analysis shows that the proposed electron transfer mechanism of the vibrational frequencies of odorants could be easily suppressed by quantum effects of nonodorant molecular vibrational modes. These and other concerns about electron transfer at ORs, together with our extensive experimental data, argue against the plausibility of the vibration theory.

The Development of the Functional Literacy Experience Scale Based upon Ecological Theory (FLESBUET) and Validity-Reliability Study

Science.gov (United States)

Özenç, Emine Gül; Dogan, M. Cihangir

2014-01-01

This study aims to perform a validity-reliability test by developing the Functional Literacy Experience Scale based upon Ecological Theory (FLESBUET) for primary education students. The study group includes 209 fifth grade students at Sabri Taskin Primary School in the Kartal District of Istanbul, Turkey during the 2010-2011 academic year.…

Validity of leptin receptor-deficiency (db/db) type 2 diabetes mellitus mice as a model of secondary osteoporosis

Science.gov (United States)

Huang, Le; You, Yong-Ke; Zhu, Tracy Y.; Zheng, Li-Zhen; Huang, Xiao-Ru; Chen, Hai-Yong; Yao, Dong; Lan, Hui-Yao; Qin, Ling

2016-06-01

This study aimed to evaluate the validation of the leptin receptor-deficient mice model for secondary osteoporosis associated with type 2 diabetes mellitus (T2DM) at bone micro-architectural level. Thirty three 36-week old male mice were divided into four groups: normal control (db/m) (n = 7), leptin receptor-deficient T2DM (db/db) (n = 8), human C-reactive protein (CRP) transgenic normal control (crp/db/m) (n = 7), and human CRP transgenic T2DM (crp/db/db) (n = 11). Lumber vertebrae (L5) and bilateral lower limbs were scanned by micro-CT to analyze trabecular and cortical bone quality. Right femora were used for three-point bending to analyze the mechanical properties. Trabecular bone quality at L5 was better in db/db or crp/db/db group in terms of bone mineral density (BMD), bone volume fraction, connectivity density, trabecular number and separation (all p  0.05). Maximum loading and energy yield in mechanical test were similar among groups while the elastic modulus in db/db and crp/db/db significantly lower than db/m. The leptin-receptor mice is not a proper model for secondary osteoporosis associated with T2DM.

Verification, validation, and reliability of predictions

International Nuclear Information System (INIS)

Pigford, T.H.; Chambre, P.L.

1987-04-01

The objective of predicting long-term performance should be to make reliable determinations of whether the prediction falls within the criteria for acceptable performance. Establishing reliable predictions of long-term performance of a waste repository requires emphasis on valid theories to predict performance. The validation process must establish the validity of the theory, the parameters used in applying the theory, the arithmetic of calculations, and the interpretation of results; but validation of such performance predictions is not possible unless there are clear criteria for acceptable performance. Validation programs should emphasize identification of the substantive issues of prediction that need to be resolved. Examples relevant to waste package performance are predicting the life of waste containers and the time distribution of container failures, establishing the criteria for defining container failure, validating theories for time-dependent waste dissolution that depend on details of the repository environment, and determining the extent of congruent dissolution of radionuclides in the UO 2 matrix of spent fuel. Prediction and validation should go hand in hand and should be done and reviewed frequently, as essential tools for the programs to design and develop repositories. 29 refs

Theory and Validation for the Collision Module

DEFF Research Database (Denmark)

Simonsen, Bo Cerup

1999-01-01

This report describes basic modelling principles, the theoretical background and validation examples for the Collision Module for the computer program DAMAGE.......This report describes basic modelling principles, the theoretical background and validation examples for the Collision Module for the computer program DAMAGE....

Enhancing Validity When Researching the "Other": Insights from Pierre Bourdieu's Theory of Social Science Research Practice

Science.gov (United States)

Naidoo, Devika

2014-01-01

This article explores aspects of Pierre Bourdieu's theory of social science research practice and discusses their relevance for enhancing validity when researching the "other." Aspects such as: a relational way of thinking about concepts, epistemology and methodology; the rigorous construction of the object of research; and…

Imidazole derivatives as angiotensin II AT1 receptor blockers: Benchmarks, drug-like calculations and quantitative structure-activity relationships modeling

Science.gov (United States)

Alloui, Mebarka; Belaidi, Salah; Othmani, Hasna; Jaidane, Nejm-Eddine; Hochlaf, Majdi

2018-03-01

We performed benchmark studies on the molecular geometry, electron properties and vibrational analysis of imidazole using semi-empirical, density functional theory and post Hartree-Fock methods. These studies validated the use of AM1 for the treatment of larger systems. Then, we treated the structural, physical and chemical relationships for a series of imidazole derivatives acting as angiotensin II AT1 receptor blockers using AM1. QSAR studies were done for these imidazole derivatives using a combination of various physicochemical descriptors. A multiple linear regression procedure was used to design the relationships between molecular descriptor and the activity of imidazole derivatives. Results validate the derived QSAR model.

Systematic development and validation of a theory-based questionnaire to assess toddler feeding.

Science.gov (United States)

Hurley, Kristen M; Pepper, M Reese; Candelaria, Margo; Wang, Yan; Caulfield, Laura E; Latta, Laura; Hager, Erin R; Black, Maureen M

2013-12-01

This paper describes the development and validation of a 27-item caregiver-reported questionnaire on toddler feeding. The development of the Toddler Feeding Behavior Questionnaire was based on a theory of interactive feeding that incorporates caregivers' responses to concerns about their children's dietary intake, appetite, size, and behaviors rather than relying exclusively on caregiver actions. Content validity included review by an expert panel (n = 7) and testing in a pilot sample (n = 105) of low-income mothers of toddlers. Construct validity and reliability were assessed among a second sample of low-income mothers of predominately African-American (70%) toddlers aged 12-32 mo (n = 297) participating in the baseline evaluation of a toddler overweight prevention study. Internal consistency (Cronbach's α: 0.64-0.87) and test-retest (0.57-0.88) reliability were acceptable for most constructs. Exploratory and confirmatory factor analyses revealed 5 theoretically derived constructs of feeding: responsive, forceful/pressuring, restrictive, indulgent, and uninvolved (root mean square error of approximation = 0.047, comparative fit index = 0.90, standardized root mean square residual = 0.06). Statistically significant (P feeding behaviors, toddler overweight status, perceived toddler fussiness, and maternal mental health. The Toddler Feeding Behavior Questionnaire adds to the field by providing a brief instrument that can be administered in 5 min to examine how caregiver-reported feeding behaviors relate to toddler health and behavior.

Novel and validated titrimetric method for determination of selected angiotensin-II-receptor antagonists in pharmaceutical preparations and its comparison with UV spectrophotometric determination

Directory of Open Access Journals (Sweden)

Shrikant H. Patil

2012-12-01

Full Text Available A novel and simple titrimetric method for determination of commonly used angiotensin-II-receptor antagonists (ARA-IIs is developed and validated. The direct acid base titration of four ARA-IIs, namely eprosartan mesylate, irbesartan, telmisartan and valsartan, was carried out in the mixture of ethanol:water (1:1 as solvent using standardized sodium hydroxide aqueous solution as titrant, either visually using phenolphthalein as an indicator or potentiometrically using combined pH electrode. The method was found to be accurate and precise, having relative standard deviation of less than 2% for all ARA-IIs studied. Also, it was shown that the method could be successfully applied to the assay of commercial pharmaceuticals containing the above-mentioned ARA-IIs. The validity of the method was tested by the recovery studies of standard addition to pharmaceuticals and the results were found to be satisfactory. Results obtained by this method were found to be in good agreement with those obtained by UV spectrophotometric method. For UV spectrophotometric analysis ethanol was used as a solvent and wavelength of 233 nm, 246 nm, 296 nm, and 250 nm was selected for determination of eprosartan mesylate, irbesartan, telmisartan, and valsartan respectively. The proposed titrimetric method is simple, rapid, convenient and sufficiently precise for quality control purposes. Keywords: Angiotensin-II-receptor antagonists, Titrimetric assay, UV spectrophotometry, Validation

Electrocatalysis of borohydride oxidation: a review of density functional theory approach combined with experimental validation

International Nuclear Information System (INIS)

Sison Escaño, Mary Clare; Arevalo, Ryan Lacdao; Kasai, Hideaki; Gyenge, Elod

2014-01-01

The electrocatalysis of borohydride oxidation is a complex, up-to-eight-electron transfer process, which is essential for development of efficient direct borohydride fuel cells. Here we review the progress achieved by density functional theory (DFT) calculations in explaining the adsorption of BH 4 − on various catalyst surfaces, with implications for electrocatalyst screening and selection. Wherever possible, we correlate the theoretical predictions with experimental findings, in order to validate the proposed models and to identify potential directions for further advancements. (topical review)

Electrocatalysis of borohydride oxidation: a review of density functional theory approach combined with experimental validation

Science.gov (United States)

Sison Escaño, Mary Clare; Lacdao Arevalo, Ryan; Gyenge, Elod; Kasai, Hideaki

2014-09-01

The electrocatalysis of borohydride oxidation is a complex, up-to-eight-electron transfer process, which is essential for development of efficient direct borohydride fuel cells. Here we review the progress achieved by density functional theory (DFT) calculations in explaining the adsorption of BH4- on various catalyst surfaces, with implications for electrocatalyst screening and selection. Wherever possible, we correlate the theoretical predictions with experimental findings, in order to validate the proposed models and to identify potential directions for further advancements.

Construct validity in Operations Management by using Rasch Measurement Theory. The case of the construct “motivation to implement continuous improvement"

Directory of Open Access Journals (Sweden)

Lidia Sanchez-Ruiz

2016-12-01

Full Text Available Construct design and validation is a common practise in the Operations Management field. In this sense, the aim of this study is to present Rasch Measurement Theory (RMT as richful and useful methodology in order to validate constructs. In order to do so, the measurement controversy in the social science is presented; then, RMT is explained as a solution for this measurement issue; after that, the different applications of RMT are described and, finally, the different stages of the validation process are presented. Thus, this work aims to serve as a guide for those researchers interested in the methodology. Therefore, a specific case is included: the validation of the construct “motivation to implement continuous improvement”.

Assessment of a recombinant androgen receptor binding assay: initial steps towards validation.

Science.gov (United States)

Freyberger, Alexius; Weimer, Marc; Tran, Hoai-Son; Ahr, Hans-Jürgen

2010-08-01

Despite more than a decade of research in the field of endocrine active compounds with affinity for the androgen receptor (AR), still no validated recombinant AR binding assay is available, although recombinant AR can be obtained from several sources. With funding from the European Union (EU)-sponsored 6th framework project, ReProTect, we developed a model protocol for such an assay based on a simple AR binding assay recently developed at our institution. Important features of the protocol were the use of a rat recombinant fusion protein to thioredoxin containing both the hinge region and ligand binding domain (LBD) of the rat AR (which is identical to the human AR-LBD) and performance in a 96-well plate format. Besides two reference compounds [dihydrotestosterone (DHT), androstenedione] ten test compounds with different affinities for the AR [levonorgestrel, progesterone, prochloraz, 17alpha-methyltestosterone, flutamide, norethynodrel, o,p'-DDT, dibutylphthalate, vinclozolin, linuron] were used to explore the performance of the assay. At least three independent experiments per compound were performed. The AR binding properties of reference and test compounds were well detected, in terms of the relative ranking of binding affinities, there was good agreement with published data obtained from experiments using recombinant AR preparations. Irrespective of the chemical nature of the compound, individual IC(50)-values for a given compound varied by not more than a factor of 2.6. Our data demonstrate that the assay reliably ranked compounds with strong, weak, and no/marginal affinity for the AR with high accuracy. It avoids the manipulation and use of animals, as a recombinant protein is used and thus contributes to the 3R concept. On the whole, this assay is a promising candidate for further validation. Copyright 2009 Elsevier Inc. All rights reserved.

Validation of experimental molecular crystal structures with dispersion-corrected density functional theory calculations.

Science.gov (United States)

van de Streek, Jacco; Neumann, Marcus A

2010-10-01

This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 Å (0.084 Å for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 A either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect.

Gonadotropins, their receptors, and the regulation of testicular functions in fish

NARCIS (Netherlands)

Schulz, Rüdiger W; Vischer, H F; Cavaco, J E; Dos Santos Rocha, M.E.; Tyler, R.C.; Goos, H.J.; Bogerd, J.

The pituitary gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) regulate steroidogenesis and spermatogenesis by activating receptors expressed by Leydig cells (LH receptor) and Sertoli cells (FSH receptor), respectively. This concept is also valid in fish, although the

Validation of the 3D finite element transport theory code EVENT for shielding applications

International Nuclear Information System (INIS)

Warner, Paul; Oliveira, R.E. de

2000-01-01

This paper is concerned with the validation of the 3D deterministic neutral-particle transport theory code EVENT for shielding applications. The code is based on the finite element-spherical harmonics (FE-P N ) method which has been extensively developed over the last decade. A general multi-group, anisotropic scattering formalism enables the code to address realistic steady state and time dependent, multi-dimensional coupled neutron/gamma radiation transport problems involving high scattering and deep penetration alike. The powerful geometrical flexibility and competitive computational effort makes the code an attractive tool for shielding applications. In recognition of this, EVENT is currently in the process of being adopted by the UK nuclear industry. The theory behind EVENT is described and its numerical implementation is outlined. Numerical results obtained by the code are compared with predictions of the Monte Carlo code MCBEND and also with the results from benchmark shielding experiments. In particular, results are presented for the ASPIS experimental configuration for both neutron and gamma ray calculations using the BUGLE 96 nuclear data library. (author)

Experimental validation of the Maxwell-Stefan theory for the description of liquid-side mass transfer-absorption of NH3 in water using a stirred cell.

NARCIS (Netherlands)

Frank, M.J.W.; Frank, M.J.W.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

1996-01-01

The main goal of this paper is to demonstrate the validity of the Maxwell-Stefan theory for the description of liquid phase mass transport processes in a binary mixture. To critically test this theory absorption experiments of ammonia in water were conducted in a stirred cell. The flux model

Validation of somatostatin receptor scintigraphy in the localization of neuroendocrine tumors

International Nuclear Information System (INIS)

Lamberts, S.W.J.; Reubi, J.C.; Krenning, E.P.

1993-01-01

Somatostatin analogs are used in the control of hormonal hypersecretion and tumor growth of patients with acromegaly, islet cell carcinomas and carcinoids. Recently we showed that somatostatin receptor positive tumors can be visualized in vivo after the administration of radionuclide-labeled somatostatin analogs. Receptor imaging was positive in 18/21 islet cell tumors, 32/37 carcinoids, 26/28 paragangliomas, 9/14 medullary thyroid carcinomas, and 5/7 small cell lung cancers. Somatostatin receptor imaging is an easy, harmless and painless diagnostic method. It localizes multiple and/or metastatic tumors, predicts the successful control of hormonal hypersecretion by octreotide and seems to be of prognostic value in certain types of cancer. This scintigraphic method might help in patient selection for clinical trials with somatostatin analogs in the treatment of neuroendocrine cancers. (orig.)

Validation of somatostatin receptor scintigraphy in the localization of neuroendocrine tumors

Energy Technology Data Exchange (ETDEWEB)

Lamberts, S.W.J. (Depts. of Medicine and Nuclear Medicine, Erasmus Univ., Rotterdam (Netherlands) Div. of Cell Biology and Experimental Cancer Research, Institution of Pathology, Bern Univ. (Switzerland)); Reubi, J.C. (Depts. of Medicine and Nuclear Medicine, Erasmus Univ., Rotterdam (Netherlands) Div. of Cell Biology and Experimental Cancer Research, Institution of Pathology, Bern Univ. (Switzerland)); Krenning, E.P. (Depts. of Medicine and Nuclear Medicine, Erasmus Univ., Rotterdam (Netherlands) Div. of Cell Biology and Experimental Cancer Research, Institution of Pathology, Bern Univ. (Switzerland))

1993-01-01

Somatostatin analogs are used in the control of hormonal hypersecretion and tumor growth of patients with acromegaly, islet cell carcinomas and carcinoids. Recently we showed that somatostatin receptor positive tumors can be visualized in vivo after the administration of radionuclide-labeled somatostatin analogs. Receptor imaging was positive in 18/21 islet cell tumors, 32/37 carcinoids, 26/28 paragangliomas, 9/14 medullary thyroid carcinomas, and 5/7 small cell lung cancers. Somatostatin receptor imaging is an easy, harmless and painless diagnostic method. It localizes multiple and/or metastatic tumors, predicts the successful control of hormonal hypersecretion by octreotide and seems to be of prognostic value in certain types of cancer. This scintigraphic method might help in patient selection for clinical trials with somatostatin analogs in the treatment of neuroendocrine cancers. (orig.).

A discussion on validity of the diffusion theory by Monte Carlo method

Science.gov (United States)

Peng, Dong-qing; Li, Hui; Xie, Shusen

2008-12-01

Diffusion theory was widely used as a basis of the experiments and methods in determining the optical properties of biological tissues. A simple analytical solution could be obtained easily from the diffusion equation after a series of approximations. Thus, a misinterpret of analytical solution would be made: while the effective attenuation coefficient of several semi-infinite bio-tissues were the same, the distribution of light fluence in the tissues would be the same. In order to assess the validity of knowledge above, depth resolved internal fluence of several semi-infinite biological tissues which have the same effective attenuation coefficient were simulated with wide collimated beam in the paper by using Monte Carlo method in different condition. Also, the influence of bio-tissue refractive index on the distribution of light fluence was discussed in detail. Our results showed that, when the refractive index of several bio-tissues which had the same effective attenuation coefficient were the same, the depth resolved internal fluence would be the same; otherwise, the depth resolved internal fluence would be not the same. The change of refractive index of tissue would have affection on the light depth distribution in tissue. Therefore, the refractive index is an important optical property of tissue, and should be taken in account while using the diffusion approximation theory.

Content Validity and Psychometric Characteristics of the "Knowledge about Older Patients Quiz" for Nurses Using Item Response Theory.

Science.gov (United States)

Dikken, Jeroen; Hoogerduijn, Jita G; Kruitwagen, Cas; Schuurmans, Marieke J

2016-11-01

To assess the content validity and psychometric characteristics of the Knowledge about Older Patients Quiz (KOP-Q), which measures nurses' knowledge regarding older hospitalized adults and their certainty regarding this knowledge. Cross-sectional. Content validity: general hospitals. Psychometric characteristics: nursing school and general hospitals in the Netherlands. Content validity: 12 nurse specialists in geriatrics. Psychometric characteristics: 107 first-year and 78 final-year bachelor of nursing students, 148 registered nurses, and 20 nurse specialists in geriatrics. Content validity: The nurse specialists rated each item of the initial KOP-Q (52 items) on relevance. Ratings were used to calculate Item-Content Validity Index and average Scale-Content Validity Index (S-CVI/ave) scores. Items with insufficient content validity were removed. Psychometric characteristics: Ratings of students, nurses, and nurse specialists were used to test for different item functioning (DIF) and unidimensionality before item characteristics (discrimination and difficulty) were examined using Item Response Theory. Finally, norm references were calculated and nomological validity was assessed. Content validity: Forty-three items remained after assessing content validity (S-CVI/ave = 0.90). Psychometric characteristics: Of the 43 items, two demonstrating ceiling effects and 11 distorting ability estimates (DIF) were subsequently excluded. Item characteristics were assessed for the remaining 30 items, all of which demonstrated good discrimination and difficulty parameters. Knowledge was positively correlated with certainty about this knowledge. The final 30-item KOP-Q is a valid, psychometrically sound, comprehensive instrument that can be used to assess the knowledge of nursing students, hospital nurses, and nurse specialists in geriatrics regarding older hospitalized adults. It can identify knowledge and certainty deficits for research purposes or serve as a tool in educational

How Far Does a Receptor Influence Vibrational Properties of an Odorant?

DEFF Research Database (Denmark)

Reese, Anna; List, Nanna Holmgaard; Kongsted, Jacob

2016-01-01

-assisted electron transfer. Through molecular dynamics simulations we elucidate the binding specificity of a receptor towards acetophenone odorant. The vibrational properties of acetophenone inside the receptor are then studied by the polarizable embedding density functional theory approach, allowing to quantify...... protein-odorant interactions. Finally, we judge whether the effects of the protein provide any indications towards the existing theories of olfaction....

Developing a Domain Theory Defining and Exemplifying a Learning Theory of Progressive Attainments

Science.gov (United States)

Bunderson, C. Victor

2011-01-01

This article defines the concept of Domain Theory, or, when educational measurement is the goal, one might call it a "Learning Theory of Progressive Attainments in X Domain". The concept of Domain Theory is first shown to be rooted in validity theory, then the concept of domain theory is expanded to amplify its necessary but long neglected…

Numerical verification/validation of the theory of coupled reactors for deuterium critical assembly, using MCNP5 and Serpent codes

International Nuclear Information System (INIS)

Hussein, M.S; Lewis, B.J.; Bonin, H.W.

2013-01-01

The theory of multipoint coupled reactors developed by multi-group transport is verified by using the probabilistic transport code MCNP5 and the continuous-energy Monte Carlo reactor physics burnup calculation Serpent code. The verification was performed by calculating the multiplication factors (or criticality factors) and coupling coefficients for a two-region test reactor known as the Deuterium Critical Assembly, DCA. The multiplication factors k eff calculated numerically and independently from simulations of the DCA by MCNP5 and Serpent codes are compared with the multiplication factors k eff calculated based on the coupled reactor theory. Excellent agreement was obtained between the multiplication factors k eff calculated with the Serpent code, with MCNP5, and from the coupled reactor theory. This analysis demonstrates that the Serpent code is valid for the multipoint coupled reactor calculations. (author)

Numerical verification/validation of the theory of coupled reactors for deuterium critical assembly, using MCNP5 and Serpent codes

Energy Technology Data Exchange (ETDEWEB)

Hussein, M.S, E-mail: mohamed.hussein@rmc.ca [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada); Lewis, B.J., E-mail: Brent.Lewis@uoit.ca [Univ. of Ontario Inst. of Technology, Faculty of Energy Systems and Nuclear Science, Oshawa, Ontario (Canada); Bonin, H.W., E-mail: bonin-h@rmc.ca [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada)

2013-07-01

The theory of multipoint coupled reactors developed by multi-group transport is verified by using the probabilistic transport code MCNP5 and the continuous-energy Monte Carlo reactor physics burnup calculation Serpent code. The verification was performed by calculating the multiplication factors (or criticality factors) and coupling coefficients for a two-region test reactor known as the Deuterium Critical Assembly, DCA. The multiplication factors k{sub eff} calculated numerically and independently from simulations of the DCA by MCNP5 and Serpent codes are compared with the multiplication factors k{sub eff} calculated based on the coupled reactor theory. Excellent agreement was obtained between the multiplication factors k{sub eff} calculated with the Serpent code, with MCNP5, and from the coupled reactor theory. This analysis demonstrates that the Serpent code is valid for the multipoint coupled reactor calculations. (author)

Systematic Development and Validation of a Theory-Based Questionnaire to Assess Toddler Feeding12

Science.gov (United States)

Hurley, Kristen M.; Pepper, M. Reese; Candelaria, Margo; Wang, Yan; Caulfield, Laura E.; Latta, Laura; Hager, Erin R.; Black, Maureen M.

2013-01-01

This paper describes the development and validation of a 27-item caregiver-reported questionnaire on toddler feeding. The development of the Toddler Feeding Behavior Questionnaire was based on a theory of interactive feeding that incorporates caregivers’ responses to concerns about their children’s dietary intake, appetite, size, and behaviors rather than relying exclusively on caregiver actions. Content validity included review by an expert panel (n = 7) and testing in a pilot sample (n = 105) of low-income mothers of toddlers. Construct validity and reliability were assessed among a second sample of low-income mothers of predominately African-American (70%) toddlers aged 12–32 mo (n = 297) participating in the baseline evaluation of a toddler overweight prevention study. Internal consistency (Cronbach’s α: 0.64–0.87) and test-retest (0.57–0.88) reliability were acceptable for most constructs. Exploratory and confirmatory factor analyses revealed 5 theoretically derived constructs of feeding: responsive, forceful/pressuring, restrictive, indulgent, and uninvolved (root mean square error of approximation = 0.047, comparative fit index = 0.90, standardized root mean square residual = 0.06). Statistically significant (P feeding behaviors, toddler overweight status, perceived toddler fussiness, and maternal mental health. The Toddler Feeding Behavior Questionnaire adds to the field by providing a brief instrument that can be administered in 5 min to examine how caregiver-reported feeding behaviors relate to toddler health and behavior. PMID:24068792

General Open Systems Theory and the Substrata-Factor Theory of Reading.

Science.gov (United States)

Kling, Martin

This study was designed to extend the generality of the Substrata-Factor Theory by two methods of investigation: (1) theoretically, to est"blish the validity of the hypothesis that an isomorphic relationship exists between the Substrata-Factor Theory and the General Open Systems Theory, and (2) experimentally, to disc"ver through a…

On the validity of the classical hydrodynamic lubrication theory applied to squeeze film dampers

International Nuclear Information System (INIS)

Danaila, S; Moraru, L

2010-01-01

Squeeze film dampers (SFD) are devices utilized to control vibrations of the shafts of high-speed rotating machinery. The SFD - squirrel cage combination is probably the most used system for tuning the stiffness and damping of the supports for rotors installed on ball bearings. Squeeze film dampers are essentially hydrodynamic bearings which contain the ball bearings housings of ball-bearings supported shafts. Consequently, the oil film within the SFD are influenced only by the precession and nutation of the shaft, that is the flow of the oil within the damper is not directly influenced by the spin of the rotor. However, in the classical theory, the flow in the thin film is also governed by the Reynolds equation. In this paper, some of the limits of the classical theory of the SFD are discussed and theoretical and experimental studies, which illustrate the ideas presented herein, are presented as well. The orbits of an unbalanced rotor that is supported by a ball-bearings-SFD-squirrel-cage assembly at one end and by rigidly mounted ball bearings at the other end are computed using the bearing forces provided by the classical short bearing theory. The numerical model also includes the properties of the squirrel cage. The parameters of the squirrel cage were measured, together with the effect of the friction within the assembly. Experimental unbalance responses were also collected for various rotation speeds and unbalances to validate the numerical simulations.

Dopamine Receptors and Parkinson's Disease

Directory of Open Access Journals (Sweden)

Shin Hisahara

2011-01-01

Full Text Available Parkinson's disease (PD is a progressive extrapyramidal motor disorder. Pathologically, this disease is characterized by the selective dopaminergic (DAergic neuronal degeneration in the substantia nigra. Correcting the DA deficiency in PD with levodopa (L-dopa significantly attenuates the motor symptoms; however, its effectiveness often declines, and L-dopa-related adverse effects emerge after long-term treatment. Nowadays, DA receptor agonists are useful medication even regarded as first choice to delay the starting of L-dopa therapy. In advanced stage of PD, they are also used as adjunct therapy together with L-dopa. DA receptor agonists act by stimulation of presynaptic and postsynaptic DA receptors. Despite the usefulness, they could be causative drugs for valvulopathy and nonmotor complication such as DA dysregulation syndrome (DDS. In this paper, physiological characteristics of DA receptor familyare discussed. We also discuss the validity, benefits, and specific adverse effects of pharmaceutical DA receptor agonist.

Retrieval of Droplet size Density Distribution from Multiple field of view Cross polarized Lidar Signals: Theory and Experimental Validation

Science.gov (United States)

2016-06-02

Retrieval of droplet-size density distribution from multiple-field-of-view cross-polarized lidar signals: theory and experimental validation...Gilles Roy, Luc Bissonnette, Christian Bastille, and Gilles Vallee Multiple-field-of-view (MFOV) secondary-polarization lidar signals are used to...use secondary polarization. A mathematical relation among the PSD, the lidar fields of view, the scattering angles, and the angular depolarization

A new measurement for the revised reinforcement sensitivity theory: psychometric criteria and genetic validation

Directory of Open Access Journals (Sweden)

Martin eReuter

2015-03-01

Full Text Available Jeffrey Gray’s Reinforcement Sensitivity Theory (RST represents one of the most influential biologically-based personality theories describing individual differences in approach and avoidance tendencies. The most prominent self-report inventory to measure individual differences in approach and avoidance behavior to date is the BIS/BAS scale by Carver & White (1994. As Gray & McNaughton (2000 revised the RST after its initial formulation in the 1970/80s, and given the Carver & White measure is based on the initial conceptualization of RST, there is a growing need for self-report inventories measuring individual differences in the revised behavioral inhibition system (BIS, behavioral activation system (BAS and the fight, flight, freezing system (FFFS. Therefore, in this paper we present a new questionnaire measuring individual differences in the revised constructs of the BIS, BAS and FFFS in N = 1814 participants (German sample. An English translated version of the new measure is also presented and tested in N = 299 English language participants. A large number of German participants (N = 1090 also filled in the BIS/BAS scales by Carver & White (1994 and the correlations between these measures are presented. Finally, this same subgroup of participants provided buccal swaps for the investigation of the arginine vasopressin receptor 1a (AVPR1a gene. Here, a functional genetic polymorphism (rs11174811 on the AVPR1a gene was shown to be associated with individual differences in both the revised BIS and classic BIS dimensions.

Importance of the pharmacological profile of the bound ligand in enrichment on nuclear receptors: toward the use of experimentally validated decoy ligands.

Science.gov (United States)

Lagarde, Nathalie; Zagury, Jean-François; Montes, Matthieu

2014-10-27

The evaluation of virtual ligand screening methods is of major importance to ensure their reliability. Taking into account the agonist/antagonist pharmacological profile should improve the quality of the benchmarking data sets since ligand binding can induce conformational changes in the nuclear receptor structure and such changes may vary according to the agonist/antagonist ligand profile. We indeed found that splitting the agonist and antagonist ligands into two separate data sets for a given nuclear receptor target significantly enhances the quality of the evaluation. The pharmacological profile of the ligand bound in the binding site of the target structure was also found to be an additional critical parameter. We also illustrate that active compound data sets for a given pharmacological activity can be used as a set of experimentally validated decoy ligands for another pharmacological activity to ensure a reliable and challenging evaluation of virtual screening methods.

Measuring theory of mind across middle childhood: Reliability and validity of the Silent Films and Strange Stories tasks.

Science.gov (United States)

Devine, Rory T; Hughes, Claire

2016-09-01

Recent years have seen a growth of research on the development of children's ability to reason about others' mental states (or "theory of mind") beyond the narrow confines of the preschool period. The overall aim of this study was to investigate the psychometric properties of a task battery composed of items from Happé's Strange Stories task and Devine and Hughes' Silent Film task. A sample of 460 ethnically and socially diverse children (211 boys) between 7 and 13years of age completed the task battery at two time points separated by 1month. The Strange Stories and Silent Film tasks were strongly correlated even when verbal ability and narrative comprehension were taken into account, and all items loaded onto a single theory-of-mind latent factor. The theory-of-mind latent factor provided reliable estimates of performance across a wide range of theory-of-mind ability and showed no evidence of differential item functioning across gender, ethnicity, or socioeconomic status. The theory-of-mind latent factor also exhibited strong 1-month test-retest reliability, and this stability did not vary as a function of child characteristics. Taken together, these findings provide evidence for the validity and reliability of the Strange Stories and Silent Film task battery as a measure of individual differences in theory of mind suitable for use across middle childhood. We consider the methodological and conceptual implications of these findings for research on theory of mind beyond the preschool years. Copyright © 2015 Elsevier Inc. All rights reserved.

The nutrition for sport knowledge questionnaire (NSKQ): development and validation using classical test theory and Rasch analysis.

Science.gov (United States)

Trakman, Gina Louise; Forsyth, Adrienne; Hoye, Russell; Belski, Regina

2017-01-01

Appropriate dietary intake can have a significant influence on athletic performance. There is a growing consensus on sports nutrition and professionals working with athletes often provide dietary education. However, due to the limitations of existing sports nutrition knowledge questionnaires, previous reports of athletes' nutrition knowledge may be inaccurate. An updated questionnaire has been developed based on a recent review of sports nutrition guidelines. The tool has been validated using a robust methodology that incorporates relevant techniques from classical test theory (CTT) and Item response theory (IRT), namely, Rasch analysis. The final questionnaire has 89 questions and six sub-sections (weight management, macronutrients, micronutrients, sports nutrition, supplements, and alcohol). The content and face validity of the tool have been confirmed based on feedback from expert sports dietitians and university sports students, respectively. The internal reliability of the questionnaire as a whole is high (KR = 0.88), and most sub-sections achieved an acceptable internal reliability. Construct validity has been confirmed, with an independent T-test revealing a significant ( p  < 0.001) difference in knowledge scores of nutrition (64 ± 16%) and non-nutrition students (51 ± 19%). Test-retest reliability has been assured, with a strong correlation ( r  = 0.92, p  < 0.001) between individuals' scores on two attempts of the test, 10 days to 2 weeks apart. Three of the sub-sections fit the Rasch Unidimensional Model. The final version of the questionnaire represents a significant improvement over previous tools. Each nutrition sub-section is unidimensional, and therefore researchers and practitioners can use these individually, as required. Use of the questionnaire will allow researchers to draw conclusions about the effectiveness of nutrition education programs, and differences in knowledge across athletes of varying ages, genders, and athletic

Nucleation theory with delayed interactions: an application to the early stages of the receptor-mediated adhesion/fusion kinetics of lipid vesicles.

Science.gov (United States)

Raudino, Antonio; Pannuzzo, Martina

2010-01-28

A semiquantitative theory aimed to describe the adhesion kinetics between soft objects, such as living cells or vesicles, has been developed. When rigid bodies are considered, the adhesion kinetics is successfully described by the classical Derjaguin, Landau, Verwey, and Overbeek (DLVO) picture, where the energy profile of two approaching bodies is given by a two asymmetrical potential wells separated by a barrier. The transition probability from the long-distance to the short-distance minimum defines the adhesion rate. Conversely, soft bodies might follow a different pathway to reach the short-distance minimum: thermally excited fluctuations give rise to local protrusions connecting the approaching bodies. These transient adhesion sites are stabilized by short-range adhesion forces (e.g., ligand-receptor interactions between membranes brought at contact distance), while they are destabilized both by repulsive forces and by the elastic deformation energy. Above a critical area of the contact site, the adhesion forces prevail: the contact site grows in size until the complete adhesion of the two bodies inside a short-distance minimum is attained. This nucleation mechanism has been developed in the framework of a nonequilibrium Fokker-Planck picture by considering both the adhesive patch growth and dissolution processes. In addition, we also investigated the effect of the ligand-receptor pairing kinetics at the adhesion site in the time course of the patch expansion. The ratio between the ligand-receptor pairing kinetics and the expansion rate of the adhesion site is of paramount relevance in determining the overall nucleation rate. The theory enables one to self-consistently include both thermodynamics (energy barrier height) and dynamic (viscosity) parameters, giving rise in some limiting cases to simple analytical formulas. The model could be employed to rationalize fusion kinetics between vesicles, provided the short-range adhesion transition is the rate

Principles of Proper Validation

DEFF Research Database (Denmark)

Esbensen, Kim; Geladi, Paul

2010-01-01

to suffer from the same deficiencies. The PPV are universal and can be applied to all situations in which the assessment of performance is desired: prediction-, classification-, time series forecasting-, modeling validation. The key element of PPV is the Theory of Sampling (TOS), which allow insight......) is critically necessary for the inclusion of the sampling errors incurred in all 'future' situations in which the validated model must perform. Logically, therefore, all one data set re-sampling approaches for validation, especially cross-validation and leverage-corrected validation, should be terminated...

Testing odorant-receptor interaction theories in humans through discrimination of isotopomers

Directory of Open Access Journals (Sweden)

Mara Andrione

2017-12-01

Full Text Available Odour reception takes place on the olfactory receptor neuron membrane, where molecular receptors interact with volatile odorant molecules. This interaction is classically thought to rely on chemical and structural features of the odorant, e.g. size, shape, functional groups. However, this model does not allow formulating a correct prediction for the smell of an odorant, suggesting that other molecular properties may play a role in the odour transduction process. An alternative model of olfaction maintains that odorant receptors can probe not only the structural and chemical features, but also the molecular vibration spectrum of the odorants. This constitutes the so-called vibration model of olfaction. According to this model, two isotopomers of the same molecule, i.e. two forms of the same molecule, one unaltered and one in which one or more hydrogen atoms are substituted with deuterium – which are therefore structurally and chemically identical, but with different molecular vibration spectra – would interact differently with an olfactory receptor, producing different olfactory perceptions in the brain. Here, we report on a duo-trio discrimination experiment conducted on human subjects, testing isotopomer pairs that have recently been shown to be differentially encoded in the honeybee brain.

Evaluating the validity of the Work Role Functioning Questionnaire (Canadian French version) using classical test theory and item response theory.

Science.gov (United States)

Hong, Quan Nha; Coutu, Marie-France; Berbiche, Djamal

2017-01-01

The Work Role Functioning Questionnaire (WRFQ) was developed to assess workers' perceived ability to perform job demands and is used to monitor presenteeism. Still few studies on its validity can be found in the literature. The purpose of this study was to assess the items and factorial composition of the Canadian French version of the WRFQ (WRFQ-CF). Two measurement approaches were used to test the WRFQ-CF: Classical Test Theory (CTT) and non-parametric Item Response Theory (IRT). A total of 352 completed questionnaires were analyzed. A four-factor and three-factor model models were tested and shown respectively good fit with 14 items (Root Mean Square Error of Approximation (RMSEA) = 0.06, Standardized Root Mean Square Residual (SRMR) = 0.04, Bentler Comparative Fit Index (CFI) = 0.98) and with 17 items (RMSEA = 0.059, SRMR = 0.048, CFI = 0.98). Using IRT, 13 problematic items were identified, of which 9 were common with CTT. This study tested different models with fewer problematic items found in a three-factor model. Using a non-parametric IRT and CTT for item purification gave complementary results. IRT is still scarcely used and can be an interesting alternative method to enhance the quality of a measurement instrument. More studies are needed on the WRFQ-CF to refine its items and factorial composition.

An Asymptotic Derivation of Weakly Nonlinear Ray Theory

Indian Academy of Sciences (India)

The transport equation for the amplitude has been deduced with an error (2) where is the small parameter appearing in the high frequency approximation. On a length scale over which Choquet–Bruhat's theory is valid, this theory reduces to the former. The theory is valid on a much larger length scale and the leading ...

Ground-water models: Validate or invalidate

Science.gov (United States)

Bredehoeft, J.D.; Konikow, Leonard F.

1993-01-01

The word validation has a clear meaning to both the scientific community and the general public. Within the scientific community the validation of scientific theory has been the subject of philosophical debate. The philosopher of science, Karl Popper, argued that scientific theory cannot be validated, only invalidated. Popper’s view is not the only opinion in this debate; however, many scientists today agree with Popper (including the authors). To the general public, proclaiming that a ground-water model is validated carries with it an aura of correctness that we do not believe many of us who model would claim. We can place all the caveats we wish, but the public has its own understanding of what the word implies. Using the word valid with respect to models misleads the public; verification carries with it similar connotations as far as the public is concerned. Our point is this: using the terms validation and verification are misleading, at best. These terms should be abandoned by the ground-water community.

How Far Does a Receptor Influence Vibrational Properties of an Odorant?

Science.gov (United States)

Reese, Anna; List, Nanna Holmgaard; Kongsted, Jacob; Solov'yov, Ilia A

2016-01-01

The biophysical mechanism of the sense of smell, or olfaction, is still highly debated. The mainstream explanation argues for a shape-based recognition of odorant molecules by olfactory receptors, while recent investigations suggest the primary olfactory event to be triggered by a vibrationally-assisted electron transfer reaction. We consider this controversy by studying the influence of a receptor on the vibrational properties of an odorant in atomistic details as the coupling between electronic degrees of freedom of the receptor and the vibrations of the odorant is the key parameter of the vibrationally-assisted electron transfer. Through molecular dynamics simulations we elucidate the binding specificity of a receptor towards acetophenone odorant. The vibrational properties of acetophenone inside the receptor are then studied by the polarizable embedding density functional theory approach, allowing to quantify protein-odorant interactions. Finally, we judge whether the effects of the protein provide any indications towards the existing theories of olfaction.

Overview of classical test theory and item response theory for the quantitative assessment of items in developing patient-reported outcomes measures.

Science.gov (United States)

Cappelleri, Joseph C; Jason Lundy, J; Hays, Ron D

2014-05-01

The US Food and Drug Administration's guidance for industry document on patient-reported outcomes (PRO) defines content validity as "the extent to which the instrument measures the concept of interest" (FDA, 2009, p. 12). According to Strauss and Smith (2009), construct validity "is now generally viewed as a unifying form of validity for psychological measurements, subsuming both content and criterion validity" (p. 7). Hence, both qualitative and quantitative information are essential in evaluating the validity of measures. We review classical test theory and item response theory (IRT) approaches to evaluating PRO measures, including frequency of responses to each category of the items in a multi-item scale, the distribution of scale scores, floor and ceiling effects, the relationship between item response options and the total score, and the extent to which hypothesized "difficulty" (severity) order of items is represented by observed responses. If a researcher has few qualitative data and wants to get preliminary information about the content validity of the instrument, then descriptive assessments using classical test theory should be the first step. As the sample size grows during subsequent stages of instrument development, confidence in the numerical estimates from Rasch and other IRT models (as well as those of classical test theory) would also grow. Classical test theory and IRT can be useful in providing a quantitative assessment of items and scales during the content-validity phase of PRO-measure development. Depending on the particular type of measure and the specific circumstances, the classical test theory and/or the IRT should be considered to help maximize the content validity of PRO measures. Copyright © 2014 Elsevier HS Journals, Inc. All rights reserved.

Method validation in pharmaceutical analysis: from theory to practical optimization

Directory of Open Access Journals (Sweden)

Jaqueline Kaleian Eserian

2015-01-01

Full Text Available The validation of analytical methods is required to obtain high-quality data. For the pharmaceutical industry, method validation is crucial to ensure the product quality as regards both therapeutic efficacy and patient safety. The most critical step in validating a method is to establish a protocol containing well-defined procedures and criteria. A well planned and organized protocol, such as the one proposed in this paper, results in a rapid and concise method validation procedure for quantitative high performance liquid chromatography (HPLC analysis.   Type: Commentary

Determination of regional flow by use of intravascular PET tracers: microvascular theory and experimental validation for pig livers

DEFF Research Database (Denmark)

Munk, O L; Bass, L; Feng, H

2003-01-01

Today, the standard approach for the kinetic analysis of dynamic PET studies is compartment models, in which the tracer and its metabolites are confined to a few well-mixed compartments. We examine whether the standard model is suitable for modern PET data or whether theories including more...... physiologic realism can advance the interpretation of dynamic PET data. A more detailed microvascular theory is developed for intravascular tracers in single-capillary and multiple-capillary systems. The microvascular models, which account for concentration gradients in capillaries, are validated and compared...... with the standard model in a pig liver study. METHODS: Eight pigs underwent a 5-min dynamic PET study after (15)O-carbon monoxide inhalation. Throughout each experiment, hepatic arterial blood and portal venous blood were sampled, and flow was measured with transit-time flow meters. The hepatic dual...

Whose consensus is it anyway? Scientific versus legalistic conceptions of validity

NARCIS (Netherlands)

Borsboom, D.

2012-01-01

Paul E. Newton provides an insightful and scholarly overview of central issues in validity theory. As he notes, many of the conceptual problems in validity theory derive from the fact that the word validity has two meanings. First, it indicates whether a test measures what it purports to measure.

Pharmacological approach of the receptors

International Nuclear Information System (INIS)

Puech, A.J.

1989-01-01

This paper explains the three main goals for clinical positron emission tomography (PET) studies: detection of receptor abnormalities in groups of patients to propose therapeutic indication of new ligands; validation of current hypothesis of drug effect; rational clinical drug development specially for dose-finding studies. (H.W.)

The validation of language tests

African Journals Online (AJOL)

KATEVG

Stellenbosch Papers in Linguistics, Vol. ... validation is necessary because of the major impact which test results can have on the many ... Messick (1989: 20) introduces his much-quoted progressive matrix (cf. table 1), which ... argue that current accounts of validity only superficially address theories of measurement.

Construct Validity of Measures of Becker's Side Bet Theory.

Science.gov (United States)

Shore, Lynn M.; Tetrick, Lois E.; Shore, Ted H.; Barksdale, Kevin

2000-01-01

Becker's side bet theory (remaining in a job because of perceived costs of leaving) was tested using data from 327 working business students. Three factors were most consistent with the theory: bureaucratic organization, nonwork-related concerns, and adjustment to social position. Attachment to the organization was significantly linked to tangible…

Optimization and in Vivo Validation of Peptide Vectors Targeting the LDL Receptor.

Science.gov (United States)

Jacquot, Guillaume; Lécorché, Pascaline; Malcor, Jean-Daniel; Laurencin, Mathieu; Smirnova, Maria; Varini, Karine; Malicet, Cédric; Gassiot, Fanny; Abouzid, Karima; Faucon, Aude; David, Marion; Gaudin, Nicolas; Masse, Maxime; Ferracci, Géraldine; Dive, Vincent; Cisternino, Salvatore; Khrestchatisky, Michel

2016-12-05

Active targeting and delivery to pathophysiological organs of interest is of paramount importance to increase specific accumulation of therapeutic drugs or imaging agents while avoiding systemic side effects. We recently developed a family of new peptide ligands of the human and rodent LDL receptor (LDLR), an attractive cell-surface receptor with high uptake activity and local enrichment in several normal or pathological tissues (Malcor et al., J. Med. Chem. 2012, 55 (5), 2227). Initial chemical optimization of the 15-mer, all natural amino acid compound 1/VH411 (DSGL[CMPRLRGC] c DPR) and structure-activity relationship (SAR) investigation led to the cyclic 8 amino acid analogue compound 22/VH445 ([cMPRLRGC] c ) which specifically binds hLDLR with a K D of 76 nM and has an in vitro blood half-life of ∼3 h. Further introduction of non-natural amino acids led to the identification of compound 60/VH4106 ([(d)-"Pen"M"Thz"RLRGC] c ), which showed the highest K D value of 9 nM. However, this latter analogue displayed the lowest in vitro blood half-life (∼1.9 h). In the present study, we designed a new set of peptide analogues, namely, VH4127 to VH4131, with further improved biological properties. Detailed analysis of the hLDLR-binding kinetics of previous and new analogues showed that the latter all displayed very high on-rates, in the 10 6 s -1. M -1 range, and off-rates varying from the low 10 -2 s -1 to the 10 -1 s -1 range. Furthermore, all these new analogues showed increased blood half-lives in vitro, reaching ∼7 and 10 h for VH4129 and VH4131, respectively. Interestingly, we demonstrate in cell-based assays using both VH445 and the most balanced optimized analogue VH4127 ([cM"Thz"RLRG"Pen"] c ), showing a K D of 18 nM and a blood half-life of ∼4.3 h, that its higher on-rate correlated with a significant increase in both the extent of cell-surface binding to hLDLR and the endocytosis potential. Finally, intravenous injection of tritium-radiolabeled 3 H

Identification of putative agouti-related protein(87-132)-melanocortin-4 receptor interactions by homology molecular modeling and validation using chimeric peptide ligands.

Science.gov (United States)

Wilczynski, Andrzej; Wang, Xiang S; Joseph, Christine G; Xiang, Zhimin; Bauzo, Rayna M; Scott, Joseph W; Sorensen, Nicholas B; Shaw, Amanda M; Millard, William J; Richards, Nigel G; Haskell-Luevano, Carrie

2004-04-22

Agouti-related protein (AGRP) is one of only two naturally known antagonists of G-protein-coupled receptors (GPCRs) identified to date. Specifically, AGRP antagonizes the brain melanocortin-3 and -4 receptors involved in energy homeostasis. Alpha-melanocyte stimulating hormone (alpha-MSH) is one of the known endogenous agonists for these melanocortin receptors. Insight into putative interactions between the antagonist AGRP amino acids with the melanocortin-4 receptor (MC4R) may be important for the design of unique ligands for the treatment of obesity related diseases and is currently lacking in the literature. A three-dimensional homology molecular model of the mouse MC4 receptor complex with the hAGRP(87-132) ligand docked into the receptor has been developed to identify putative antagonist ligand-receptor interactions. Key putative AGRP-MC4R interactions include the Arg111 of hAGRP(87-132) interacting in a negatively charged pocket located in a cavity formed by transmembrane spanning (TM) helices 1, 2, 3, and 7, capped by the acidic first extracellular loop (EL1) and specifically with the conserved melanocortin receptor residues mMC4R Glu92 (TM2), mMC4R Asp114 (TM3), and mMC4R Asp118 (TM3). Additionally, Phe112 and Phe113 of hAGRP(87-132) putatively interact with an aromatic hydrophobic pocket formed by the mMC4 receptor residues Phe176 (TM4), Phe193 (TM5), Phe253 (TM6), and Phe254 (TM6). To validate the AGRP-mMC4R model complex presented herein from a ligand perspective, we generated nine chimeric peptide ligands based on a modified antagonist template of the hAGRP(109-118) (Tyr-c[Asp-Arg-Phe-Phe-Asn-Ala-Phe-Dpr]-Tyr-NH(2)). In these chimeric ligands, the antagonist AGRP Arg-Phe-Phe residues were replaced by the melanocortin agonist His/D-Phe-Arg-Trp amino acids. These peptides resulted in agonist activity at the mouse melanocortin receptors (mMC1R and mMC3-5Rs). The most notable results include the identification of a novel subnanomolar melanocortin peptide

In-house validation of a liquid chromatography-tandem mass spectrometry method for the determination of selective androgen receptor modulators (SARMS) in bovine urine.

Science.gov (United States)

Schmidt, Kathrin S; Mankertz, Joachim

2018-06-01

A sensitive and robust LC-MS/MS method allowing the rapid screening and confirmation of selective androgen receptor modulators in bovine urine was developed and successfully validated according to Commission Decision 2002/657/EC, chapter 3.1.3 'alternative validation', by applying a matrix-comprehensive in-house validation concept. The confirmation of the analytes in the validation samples was achieved both on the basis of the MRM ion ratios as laid down in Commission Decision 2002/657/EC and by comparison of their enhanced product ion (EPI) spectra with a reference mass spectral library by making use of the QTRAP technology. Here, in addition to the MRM survey scan, EPI spectra were generated in a data-dependent way according to an information-dependent acquisition criterion. Moreover, stability studies of the analytes in solution and in matrix according to an isochronous approach proved the stability of the analytes in solution and in matrix for at least the duration of the validation study. To identify factors that have a significant influence on the test method in routine analysis, a factorial effect analysis was performed. To this end, factors considered to be relevant for the method in routine analysis (e.g. operator, storage duration of the extracts before measurement, different cartridge lots and different hydrolysis conditions) were systematically varied on two levels. The examination of the extent to which these factors influence the measurement results of the individual analytes showed that none of the validation factors exerts a significant influence on the measurement results.

Overview of Classical Test Theory and Item Response Theory for Quantitative Assessment of Items in Developing Patient-Reported Outcome Measures

Science.gov (United States)

Cappelleri, Joseph C.; Lundy, J. Jason; Hays, Ron D.

2014-01-01

Introduction The U.S. Food and Drug Administration’s patient-reported outcome (PRO) guidance document defines content validity as “the extent to which the instrument measures the concept of interest” (FDA, 2009, p. 12). “Construct validity is now generally viewed as a unifying form of validity for psychological measurements, subsuming both content and criterion validity” (Strauss & Smith, 2009, p. 7). Hence both qualitative and quantitative information are essential in evaluating the validity of measures. Methods We review classical test theory and item response theory approaches to evaluating PRO measures including frequency of responses to each category of the items in a multi-item scale, the distribution of scale scores, floor and ceiling effects, the relationship between item response options and the total score, and the extent to which hypothesized “difficulty” (severity) order of items is represented by observed responses. Conclusion Classical test theory and item response theory can be useful in providing a quantitative assessment of items and scales during the content validity phase of patient-reported outcome measures. Depending on the particular type of measure and the specific circumstances, either one or both approaches should be considered to help maximize the content validity of PRO measures. PMID:24811753

Water soluble and efficient amino acid Schiff base receptor for reversible fluorescence turn-on detection of Zn2+ ions: Quantum chemical calculations and detection of bacteria

Science.gov (United States)

Subha, L.; Balakrishnan, C.; Natarajan, Satheesh; Theetharappan, M.; Subramanian, Balanehru; Neelakantan, M. A.

2016-01-01

An amino acid Schiff base (R) capable of recognizing Zn2+ ions selectively and sensitively in an aqueous medium was prepared and characterized. Upon addition of Zn2+ ions, the receptor exhibits fluorescence intensity enhancements ( 40 fold) at 460 nm (quantum yield, Φ = 0.05 for R and Φ = 0.18 for R-Zn2+) and can be detected by naked eye under UV light. The receptor can recognize the Zn2+ (1.04 × 10- 8 M) selectively for other metal ions in the pH range of 7.5-11. The Zn2+ chelation with R decreases the loss of energy through non-radiative transition and leads to fluorescence enhancement. The binding mode of the receptor with Zn2+ was investigated by 1H NMR titration and further validated by ESI-MS. The elemental color mapping and SEM/EDS analysis were also used to study the binding of R with Zn2+. Density functional theory calculations were carried out to understand the binding mechanism. The receptor was applied as a microbial sensor for Escherichia coli and Staphylococcus aureus.

JacketSE: An Offshore Wind Turbine Jacket Sizing Tool; Theory Manual and Sample Usage with Preliminary Validation

Energy Technology Data Exchange (ETDEWEB)

Damiani, Rick [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-02-08

This manual summarizes the theory and preliminary verifications of the JacketSE module, which is an offshore jacket sizing tool that is part of the Wind-Plant Integrated System Design & Engineering Model toolbox. JacketSE is based on a finite-element formulation and on user-prescribed inputs and design standards' criteria (constraints). The physics are highly simplified, with a primary focus on satisfying ultimate limit states and modal performance requirements. Preliminary validation work included comparing industry data and verification against ANSYS, a commercial finite-element analysis package. The results are encouraging, and future improvements to the code are recommended in this manual.

Question of Drug Workers under the Prism Theory of Axel Honneth recognition . Human Right to Work and his pretension of Universal Validity

Directory of Open Access Journals (Sweden)

Maria Cecília Máximo Teodoro

2016-06-01

Full Text Available Relate the theme regarding the Theory of Recognition Axel Honnet, the human right to work as a human right to claim to universal validity, from the perspective of the Declaration of Fundamental Principles and Rights at Work ILO, for purposes of setting parameters and recognition of social (re integration of chemical class dependent workers is the main goal of this article. We will analyze the theoretical framework in which the pursuit of human dignity at work is the goal of the state to which we treat below the dignity of man as a right whose claim to universal validity is based on the recognition of the theory of Axel Honneth . That said, we analyze the possible dignity of man at work in a global context from the recognition of new rights, especially with regard to the category of workers who occupy the social portion of chemical-dependent, whose participation in the social process is prevented, creating a category of workers socially excluded, which is intended to overcome.

Microcontinuum field theories

CERN Document Server

Eringen, A Cemal

1999-01-01

Microcontinuum field theories constitute an extension of classical field theories -- of elastic bodies, deformations, electromagnetism, and the like -- to microscopic spaces and short time scales. Material bodies are here viewed as collections of large numbers of deformable particles, much as each volume element of a fluid in statistical mechanics is viewed as consisting of a large number of small particles for which statistical laws are valid. Classical continuum theories are valid when the characteristic length associated with external forces or stimuli is much larger than any internal scale of the body under consideration. When the characteristic lengths are comparable, however, the response of the individual constituents becomes important, for example, in considering the fluid or elastic properties of blood, porous media, polymers, liquid crystals, slurries, and composite materials. This volume is concerned with the kinematics of microcontinua. It begins with a discussion of strain, stress tensors, balanc...

Knock-In Mice with NOP-eGFP Receptors Identify Receptor Cellular and Regional Localization.

Science.gov (United States)

Ozawa, Akihiko; Brunori, Gloria; Mercatelli, Daniela; Wu, Jinhua; Cippitelli, Andrea; Zou, Bende; Xie, Xinmin Simon; Williams, Melissa; Zaveri, Nurulain T; Low, Sarah; Scherrer, Grégory; Kieffer, Brigitte L; Toll, Lawrence

2015-08-19

The nociceptin/orphanin FQ (NOP) receptor, the fourth member of the opioid receptor family, is involved in many processes common to the opioid receptors including pain and drug abuse. To better characterize receptor location and trafficking, knock-in mice were created by inserting the gene encoding enhanced green fluorescent protein (eGFP) into the NOP receptor gene (Oprl1) and producing mice expressing a functional NOP-eGFP C-terminal fusion in place of the native NOP receptor. The NOP-eGFP receptor was present in brain of homozygous knock-in animals in concentrations somewhat higher than in wild-type mice and was functional when tested for stimulation of [(35)S]GTPγS binding in vitro and in patch-clamp electrophysiology in dorsal root ganglia (DRG) neurons and hippocampal slices. Inhibition of morphine analgesia was equivalent when tested in knock-in and wild-type mice. Imaging revealed detailed neuroanatomy in brain, spinal cord, and DRG and was generally consistent with in vitro autoradiographic imaging of receptor location. Multicolor immunohistochemistry identified cells coexpressing various spinal cord and DRG cellular markers, as well as coexpression with μ-opioid receptors in DRG and brain regions. Both in tissue slices and primary cultures, the NOP-eGFP receptors appear throughout the cell body and in processes. These knock-in mice have NOP receptors that function both in vitro and in vivo and appear to be an exceptional tool to study receptor neuroanatomy and correlate with NOP receptor function. The NOP receptor, the fourth member of the opioid receptor family, is involved in pain, drug abuse, and a number of other CNS processes. The regional and cellular distribution has been difficult to determine due to lack of validated antibodies for immunohistochemical analysis. To provide a new tool for the investigation of receptor localization, we have produced knock-in mice with a fluorescent-tagged NOP receptor in place of the native NOP receptor. These

Bridging the gap between neurocognitive processing theory and performance validity assessment among the cognitively impaired: a review and methodological approach.

Science.gov (United States)

Leighton, Angela; Weinborn, Michael; Maybery, Murray

2014-10-01

Bigler (2012) and Larrabee (2012) recently addressed the state of the science surrounding performance validity tests (PVTs) in a dialogue highlighting evidence for the valid and increased use of PVTs, but also for unresolved problems. Specifically, Bigler criticized the lack of guidance from neurocognitive processing theory in the PVT literature. For example, individual PVTs have applied the simultaneous forced-choice methodology using a variety of test characteristics (e.g., word vs. picture stimuli) with known neurocognitive processing implications (e.g., the "picture superiority effect"). However, the influence of such variations on classification accuracy has been inadequately evaluated, particularly among cognitively impaired individuals. The current review places the PVT literature in the context of neurocognitive processing theory, and identifies potential methodological factors to account for the significant variability we identified in classification accuracy across current PVTs. We subsequently evaluated the utility of a well-known cognitive manipulation to provide a Clinical Analogue Methodology (CAM), that is, to alter the PVT performance of healthy individuals to be similar to that of a cognitively impaired group. Initial support was found, suggesting the CAM may be useful alongside other approaches (analogue malingering methodology) for the systematic evaluation of PVTs, particularly the influence of specific neurocognitive processing components on performance.

Theory and Validity of Life Satisfaction Scales

Science.gov (United States)

Diener, Ed; Inglehart, Ronald; Tay, Louis

2013-01-01

National accounts of subjective well-being are being considered and adopted by nations. In order to be useful for policy deliberations, the measures of life satisfaction must be psychometrically sound. The reliability, validity, and sensitivity to change of life satisfaction measures are reviewed. The scales are stable under unchanging conditions,…

Estimating uncertainty of inference for validation

Energy Technology Data Exchange (ETDEWEB)

Booker, Jane M [Los Alamos National Laboratory; Langenbrunner, James R [Los Alamos National Laboratory; Hemez, Francois M [Los Alamos National Laboratory; Ross, Timothy J [UNM

2010-09-30

We present a validation process based upon the concept that validation is an inference-making activity. This has always been true, but the association has not been as important before as it is now. Previously, theory had been confirmed by more data, and predictions were possible based on data. The process today is to infer from theory to code and from code to prediction, making the role of prediction somewhat automatic, and a machine function. Validation is defined as determining the degree to which a model and code is an accurate representation of experimental test data. Imbedded in validation is the intention to use the computer code to predict. To predict is to accept the conclusion that an observable final state will manifest; therefore, prediction is an inference whose goodness relies on the validity of the code. Quantifying the uncertainty of a prediction amounts to quantifying the uncertainty of validation, and this involves the characterization of uncertainties inherent in theory/models/codes and the corresponding data. An introduction to inference making and its associated uncertainty is provided as a foundation for the validation problem. A mathematical construction for estimating the uncertainty in the validation inference is then presented, including a possibility distribution constructed to represent the inference uncertainty for validation under uncertainty. The estimation of inference uncertainty for validation is illustrated using data and calculations from Inertial Confinement Fusion (ICF). The ICF measurements of neutron yield and ion temperature were obtained for direct-drive inertial fusion capsules at the Omega laser facility. The glass capsules, containing the fusion gas, were systematically selected with the intent of establishing a reproducible baseline of high-yield 10{sup 13}-10{sup 14} neutron output. The deuterium-tritium ratio in these experiments was varied to study its influence upon yield. This paper on validation inference is the

Nonperturbative perturbation theory

International Nuclear Information System (INIS)

Bender, C.M.

1989-01-01

In this talk we describe a recently proposed graphical perturbative calculational scheme for quantum field theory. The basic idea is to expand in the power of the interaction term. For example, to solve a λφ 4 theory in d-dimensional space-time, we introduce a small parameter δ and consider a λ(φ 2 ) 1+δ field theory. We show how to expand such a theory as a series in powers of δ. The resulting perturbation series appears to have a finite radius of convergence and numerical results for low-dimensional models are good. We have computed the two-point and four-point Green's functions to second order in powers of δ and the 2n-point Green's functions (n>2) to order δ. We explain how to renormalize the theory and show that, to first order in powers of δ, when δ>0 and d≥4 the theory is free. This conclusion remains valid to second order in powers of δ, and we believe that it remains valid to all orders in powers of δ. The new perturbative scheme is consistent with global supersymmetry invariance. We examine a two-dimensional supersymmetric quantum field theory in which we do not know of any other means for doing analytical calculations. We illustrate the power of this new technique by computing the ground-state energy density E to second order in this new perturbation theory. We show that there is a beautiful and delicate cancellation between infinite classes of graphs which leads to the result that E=0. (orig.)

Combining Stochastic Deformation/Relaxation and Intermolecular Contacts Analysis for Extracting Pharmacophores from Ligand-Receptor Complexes.

Science.gov (United States)

Hatmal, Ma'mon M; Taha, Mutasem O

2018-04-23

We previously combined molecular dynamics (classical or simulated annealing) with ligand-receptor contacts analysis as a means to extract valid pharmacophore model(s) from single ligand-receptor complexes. However, molecular dynamics methods are computationally expensive and time-consuming. Here we describe a novel method for extracting valid pharmacophore model(s) from a single crystallographic structure within a reasonable time scale. The new method is based on ligand-receptor contacts analysis following energy relaxation of a predetermined set of randomly deformed complexes generated from the targeted crystallographic structure. Ligand-receptor contacts maintained across many deformed/relaxed structures are assumed to be critical and used to guide pharmacophore development. This methodology was implemented to develop valid pharmacophore models for PI3K-γ, RENIN, and JAK1. The resulting pharmacophore models were validated by receiver operating characteristic (ROC) analysis against inhibitors extracted from the CHEMBL database. Additionally, we implemented pharmacophores extracted from PI3K-γ to search for new inhibitors from the National Cancer Institute list of compounds. The process culminated in new PI3K-γ/mTOR inhibitory leads of low micromolar IC 50 s.

General covariance and quantum theory

International Nuclear Information System (INIS)

Mashhoon, B.

1986-01-01

The extension of the principle of relativity to general coordinate systems is based on the hypothesis that an accelerated observer is locally equivalent to a hypothetical inertial observer with the same velocity as the noninertial observer. This hypothesis of locality is expected to be valid for classical particle phenomena as well as for classical wave phenomena but only in the short-wavelength approximation. The generally covariant theory is therefore expected to be in conflict with the quantum theory which is based on wave-particle duality. This is explicitly demonstrated for the frequency of electromagnetic radiation measured by a uniformly rotating observer. The standard Doppler formula is shown to be valid only in the geometric optics approximation. A new definition for the frequency is proposed, and the resulting formula for the frequency measured by the rotating observer is shown to be consistent with expectations based on the classical theory of electrons. A tentative quantum theory is developed on the basis of the generalization of the Bohr frequency condition to include accelerated observers. The description of the causal sequence of events is assumed to be independent of the motion of the observer. Furthermore, the quantum hypothesis is supposed to be valid for all observers. The implications of this theory are critically examined. The new formula for frequency, which is still based on the hypothesis of locality, leads to the observation of negative energy quanta by the rotating observer and is therefore in conflict with the quantum theory

TLX: An elusive receptor.

Science.gov (United States)

Benod, Cindy; Villagomez, Rosa; Webb, Paul

2016-03-01

TLX (tailless receptor) is a member of the nuclear receptor superfamily and belongs to a class of nuclear receptors for which no endogenous or synthetic ligands have yet been identified. TLX is a promising therapeutic target in neurological disorders and brain tumors. Thus, regulatory ligands for TLX need to be identified to complete the validation of TLX as a useful target and would serve as chemical probes to pursue the study of this receptor in disease models. It has recently been proved that TLX is druggable. However, to identify potent and specific TLX ligands with desirable biological activity, a deeper understanding of where ligands bind, how they alter TLX conformation and of the mechanism by which TLX mediates the transcription of its target genes is needed. While TLX is in the process of escaping from orphanhood, future ligand design needs to progress in parallel with improved understanding of (i) the binding cavity or surfaces to target with small molecules on the TLX ligand binding domain and (ii) the nature of the TLX coregulators in particular cell and disease contexts. Both of these topics are discussed in this review. Copyright © 2015 Elsevier Ltd. All rights reserved.

Validating presupposed versus focused text information.

Science.gov (United States)

Singer, Murray; Solar, Kevin G; Spear, Jackie

2017-04-01

There is extensive evidence that readers continually validate discourse accuracy and congruence, but that they may also overlook conspicuous text contradictions. Validation may be thwarted when the inaccurate ideas are embedded sentence presuppositions. In four experiments, we examined readers' validation of presupposed ("given") versus new text information. Throughout, a critical concept, such as a truck versus a bus, was introduced early in a narrative. Later, a character stated or thought something about the truck, which therefore matched or mismatched its antecedent. Furthermore, truck was presented as either given or new information. Mismatch target reading times uniformly exceeded the matching ones by similar magnitudes for given and new concepts. We obtained this outcome using different grammatical constructions and with different antecedent-target distances. In Experiment 4, we examined only given critical ideas, but varied both their matching and the main verb's factivity (e.g., factive know vs. nonfactive think). The Match × Factivity interaction closely resembled that previously observed for new target information (Singer, 2006). Thus, readers can successfully validate given target information. Although contemporary theories tend to emphasize either deficient or successful validation, both types of theory can accommodate the discourse and reader variables that may regulate validation.

Validation and Design Science Research in Information Systems

NARCIS (Netherlands)

Sol, H G; Gonzalez, Rafael A.; Mora, Manuel

2012-01-01

Validation within design science research in Information Systems (DSRIS) is much debated. The relationship of validation to artifact evaluation is still not clear. This chapter aims at elucidating several components of DSRIS in relation to validation. The role of theory and theorizing are an

Long-Term Impact of Valid Case Criterion on Capturing Population-Level Growth under Item Response Theory Equating. Research Report. ETS RR-17-17

Science.gov (United States)

Deng, Weiling; Monfils, Lora

2017-01-01

Using simulated data, this study examined the impact of different levels of stringency of the valid case inclusion criterion on item response theory (IRT)-based true score equating over 5 years in the context of K-12 assessment when growth in student achievement is expected. Findings indicate that the use of the most stringent inclusion criterion…

On the validity of the effective field theory approach to SM precision tests

Energy Technology Data Exchange (ETDEWEB)

Contino, Roberto [EPFL, Lausanne (Switzerland). Inst. de Theorie des Phenomenes Physiques; CERN, Geneva (Switzerland). Theoretical Physics Dept.; Falkowski, Adam [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique; Goertz, Florian; Riva, Francesco [CERN, Geneva (Switzerland). Theoretical Physics Dept.; Grojean, Christophe [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2016-09-15

We discuss the conditions for an effective field theory (EFT) to give an adequate low-energy description of an underlying physics beyond the Standard Model (SM). Starting from the EFT where the SM is extended by dimension-6 operators, experimental data can be used without further assumptions to measure (or set limits on) the EFT parameters. The interpretation of these results requires instead a set of broad assumptions (e.g. power counting rules) on the UV dynamics. This allows one to establish, in a bottom-up approach, the validity range of the EFT description, and to assess the error associated with the truncation of the EFT series. We give a practical prescription on how experimental results could be reported, so that they admit a maximally broad range of theoretical interpretations. Namely, the experimental constraints on dimension-6 operators should be reported as functions of the kinematic variables that set the relevant energy scale of the studied process. This is especially important for hadron collider experiments where collisions probe a wide range of energy scales.

Towards Validating Risk Indicators Based on Measurement Theory (Extended version)

NARCIS (Netherlands)

Morali, A.; Wieringa, Roelf J.

Due to the lack of quantitative information and for cost-efficiency, most risk assessment methods use partially ordered values (e.g. high, medium, low) as risk indicators. In practice it is common to validate risk indicators by asking stakeholders whether they make sense. This way of validation is

Kerlinger's Criterial Referents Theory Revisited.

Science.gov (United States)

Zak, Itai; Birenbaum, Menucha

1980-01-01

Kerlinger's criterial referents theory of attitudes was tested cross-culturally by administering an education attitude referents summated-rating scale to 713 individuals in Israel. The response pattern to criterial and noncriterial referents was examined. Results indicated empirical cross-cultural validity of theory, but questioned measuring…

Multipactor theory for multicarrier signals

International Nuclear Information System (INIS)

Anza, S.; Vicente, C.; Gil, J.; Mattes, M.; Raboso, D.; Boria, V. E.; Gimeno, B.

2011-01-01

This work presents a new theory of multipactor under multicarrier signals for parallel-plate geometries, assuming a homogeneous electric field and one-dimensional electron motion. It is the generalization of the nonstationary multipactor theory for single-carrier signals [S. Anza et al.,Phys. Plasmas 17, 062110 (2010)]. It is valid for multicarrier signals with an arbitrary number of carriers with different amplitude, arbitrary frequency, and phase conditions and for any material coating. This new theory is able to model the real dynamics of the electrons during the multipactor discharge for both single and double surface interactions. Among other parameters of the discharge, it calculates the evolution in time of the charge growth, electron absorption, and creation rates as well as the instantaneous secondary emission yield and order. An extensive set of numerical tests with particle-in-cell software has been carried out in order to validate the theory under many different conditions. This theoretical development constitutes the first multipactor theory which completely characterizes the multipactor discharge for arbitrary multicarrier signals, setting the first step for further investigations in the field.

Minute Impurities Contribute Significantly to Olfactory Receptor Ligand Studies: Tales from Testing the Vibration Theory.

Science.gov (United States)

Paoli, M; Münch, D; Haase, A; Skoulakis, E; Turin, L; Galizia, C G

2017-01-01

Several studies have attempted to test the vibrational hypothesis of odorant receptor activation in behavioral and physiological studies using deuterated compounds as odorants. The results have been mixed. Here, we attempted to test how deuterated compounds activate odorant receptors using calcium imaging of the fruit fly antennal lobe. We found specific activation of one area of the antennal lobe corresponding to inputs from a specific receptor. However, upon more detailed analysis, we discovered that an impurity of 0.0006% ethyl acetate in a chemical sample of benzaldehyde-d 5 was entirely responsible for a sizable odorant-evoked response in Drosophila melanogaster olfactory receptor cells expressing dOr42b. Without gas chromatographic purification within the experimental setup, this impurity would have created a difference in the responses of deuterated and nondeuterated benzaldehyde, suggesting that dOr42b be a vibration sensitive receptor, which we show here not to be the case. Our results point to a broad problem in the literature on use of non-GC-pure compounds to test receptor selectivity, and we suggest how the limitations can be overcome in future studies.

Exploring the reliability and validity of the social-moral awareness test.

Science.gov (United States)

Livesey, Alexandra; Dodd, Karen; Pote, Helen; Marlow, Elizabeth

2012-11-01

The aim of the study was to explore the validity of the social-moral awareness test (SMAT) a measure designed for assessing socio-moral rule knowledge and reasoning in people with learning disabilities. Comparisons between Theory of Mind and socio-moral reasoning allowed the exploration of construct validity of the tool. Factor structure, reliability and discriminant validity were also assessed. Seventy-one participants with mild-moderate learning disabilities completed the two scales of the SMAT and two False Belief Tasks for Theory of Mind. Reliability of the SMAT was very good, and the scales were shown to be uni-dimensional in factor structure. There was a significant positive relationship between Theory of Mind and both SMAT scales. There is early evidence of the construct validity and reliability of the SMAT. Further assessment of the validity of the SMAT will be required. © 2012 Blackwell Publishing Ltd.

Development and validation of the Alcohol Myopia Scale.

Science.gov (United States)

Lac, Andrew; Berger, Dale E

2013-09-01

Alcohol myopia theory conceptualizes the ability of alcohol to narrow attention and how this demand on mental resources produces the impairments of self-inflation, relief, and excess. The current research was designed to develop and validate a scale based on this framework. People who were alcohol users rated items representing myopic experiences arising from drinking episodes in the past month. In Study 1 (N = 260), the preliminary 3-factor structure was supported by exploratory factor analysis. In Study 2 (N = 289), the 3-factor structure was substantiated with confirmatory factor analysis, and it was superior in fit to an empirically indefensible 1-factor structure. The final 14-item scale was evaluated with internal consistency reliability, discriminant validity, convergent validity, criterion validity, and incremental validity. The alcohol myopia scale (AMS) illuminates conceptual underpinnings of this theory and yields insights for understanding the tunnel vision that arises from intoxication.

Hormone receptor densities in relation to 10B neutron capture therapy

International Nuclear Information System (INIS)

Hechter, O.; Schwartz, I.L.

1982-01-01

This presentation is a theoretical discussion of the possibility that appropriate steroid-carborane derivatives might be used to selectively deliver boron-10 ( 10 B) to tumor cells with sex-hormone receptors in sufficient concentration for effective neutron capture theory (NCT) of hormone-dependent mammary and prostatic cancer. The results indicate the concentrations of androgen receptors (AR) and progesterone receptors (PR) in malignant prostatic cells or of estrogen receptors (ER) in malignant mammary cells are two low to achieve nuclear 10 B concentrations of 1 + g per g of tumor by using a steroid ligand coupled to a single carborane cage

Certification Testing as an Illustration of Argument-Based Validation

Science.gov (United States)

Kane, Michael

2004-01-01

The theories of validity developed over the past 60 years are quite sophisticated, but the methodology of validity is not generally very effective. The validity evidence for major testing programs is typically much weaker than the evidence for more technical characteristics such as reliability. In addition, most validation efforts have a strong…

Conceptualizing Essay Tests' Reliability and Validity: From Research to Theory

Science.gov (United States)

Badjadi, Nour El Imane

2013-01-01

The current paper on writing assessment surveys the literature on the reliability and validity of essay tests. The paper aims to examine the two concepts in relationship with essay testing as well as to provide a snapshot of the current understandings of the reliability and validity of essay tests as drawn in recent research studies. Bearing in…

Testing for the validity of purchasing power parity theory both in the long-run and the short-run for ASEAN-5

Science.gov (United States)

Choji, Niri Martha; Sek, Siok Kun

2017-11-01

The purchasing power parity theory says that the trade rates among two nations ought to be equivalent to the proportion of the total price levels between the two nations. For more than a decade, there has been substantial interest in testing for the validity of the Purchasing Power Parity (PPP) empirically. This paper performs a series of tests to see if PPP is valid for ASEAN-5 nations for the period of 2000-2016 using monthly data. For this purpose, we conducted four different tests of stationarity, two cointegration tests (Pedroni and Westerlund), and also the VAR model. The stationarity (unit root) tests reveal that the variables are not stationary at levels however stationary at first difference. Cointegration test results did not reject the H0 of no cointegration implying the absence long-run association among the variables and results of the VAR model did not reveal a strong short-run relationship. Based on the data, we, therefore, conclude that PPP is not valid in long-and short-run for ASEAN-5 during 2000-2016.

Minute Impurities Contribute Significantly to Olfactory Receptor Ligand Studies: Tales from Testing the Vibration Theory

OpenAIRE

Paoli, M.; M?nch, D.; Haase, A.; Skoulakis, E.; Turin, L.; Galizia, C. G.

2017-01-01

Several studies have attempted to test the vibrational hypothesis of odorant receptor activation in behavioral and physiological studies using deuterated compounds as odorants. The results have been mixed. Here, we attempted to test how deuterated compounds activate odorant receptors using calcium imaging of the fruit fly antennal lobe. We found specific activation of one area of the antennal lobe corresponding to inputs from a specific receptor. However, upon more detailed analysis, we disco...

Unresolved issues in theories of autoimmune disease using myocarditis as a framework

OpenAIRE

Root-Bernstein, Robert; Fairweather, DeLisa

2014-01-01

Many theories of autoimmune disease have been proposed since the discovery that the immune system can attack the body. These theories include the hidden or cryptic antigen theory, modified antigen theory, T cell bypass, T cell-B cell mismatch, epitope spread or drift, the bystander effect, molecular mimicry, anti-idiotype theory, antigenic complementarity, and dual-affinity T cell receptors. We critically review these theories and relevant mathematical models as they apply to autoimmune myoca...

Perturbation Theory for Open Two-Level Nonlinear Quantum Systems

International Nuclear Information System (INIS)

Zhang Zhijie; Jiang Dongguang; Wang Wei

2011-01-01

Perturbation theory is an important tool in quantum mechanics. In this paper, we extend the traditional perturbation theory to open nonlinear two-level systems, treating decoherence parameter γ as a perturbation. By this virtue, we give a perturbative solution to the master equation, which describes a nonlinear open quantum system. The results show that for small decoherence rate γ, the ratio of the nonlinear rate C to the tunneling coefficient V (i.e., r = C/V) determines the validity of the perturbation theory. For small ratio r, the perturbation theory is valid, otherwise it yields wrong results. (general)

Neutrons moderation theory; Theorie du ralentissement des neutrons

Energy Technology Data Exchange (ETDEWEB)

Vigier, J P

1949-07-01

This report gives a summarized presentation of the theory of fast neutrons diffusion and moderation in a given environment as elaborated by M. Langevin, E. Fermi, R. Marshak and others. This statistical theory is based on three assumptions: there is no inelastic diffusion, the elastic diffusion has a spherical symmetry with respect to the center of gravity of the neutron-nucleus system (s-scattering), and the effects of chemical bonds and thermal agitation of nuclei are neglected. The first chapter analyzes the Boltzmann equation of moderation, its first approximate solution (age-velocity equation) and its domain of validity, the extension of the age-velocity theory (general solution) and the boundary conditions, the upper order approximation (spherical harmonics method and Laplace transformation), the asymptotic solutions, and the theory of spatial momenta. The second chapter analyzes the energy distribution of delayed neutrons (stationary and non-stationary cases). (J.S.)

How to Map Theory: Reliable Methods Are Fruitless Without Rigorous Theory.

Science.gov (United States)

Gray, Kurt

2017-09-01

Good science requires both reliable methods and rigorous theory. Theory allows us to build a unified structure of knowledge, to connect the dots of individual studies and reveal the bigger picture. Some have criticized the proliferation of pet "Theories," but generic "theory" is essential to healthy science, because questions of theory are ultimately those of validity. Although reliable methods and rigorous theory are synergistic, Action Identification suggests psychological tension between them: The more we focus on methodological details, the less we notice the broader connections. Therefore, psychology needs to supplement training in methods (how to design studies and analyze data) with training in theory (how to connect studies and synthesize ideas). This article provides a technique for visually outlining theory: theory mapping. Theory mapping contains five elements, which are illustrated with moral judgment and with cars. Also included are 15 additional theory maps provided by experts in emotion, culture, priming, power, stress, ideology, morality, marketing, decision-making, and more (see all at theorymaps.org ). Theory mapping provides both precision and synthesis, which helps to resolve arguments, prevent redundancies, assess the theoretical contribution of papers, and evaluate the likelihood of surprising effects.

Science of Water Leaks: Validated Theory for Moisture Flow in Microchannels and Nanochannels.

Science.gov (United States)

Lei, Wenwen; Fong, Nicole; Yin, Yongbai; Svehla, Martin; McKenzie, David R

2015-10-27

Water is ubiquitous; the science of its transport in micro- and nanochannels has applications in electronics, medicine, filtration, packaging, and earth and planetary science. Validated theory for water vapor and two-phase water flows is a "missing link"; completing it enables us to define and quantify flow in a set of four standard leak configurations with dimensions from the nanoscale to the microscale. Here we report the first measurements of water vapor flow rates through four silica microchannels as a function of humidity, including under conditions when air is present as a background gas. An important finding is that the tangential momentum accommodation coefficient (TMAC) is strongly modified by surface layers of adsorbed water molecules, in agreement with previous work on the TMAC for nitrogen molecules impacting a silica surface in the presence of moisture. We measure enhanced flow rates for two-phase flows in silica microchannels driven by capillary filling. For the measurement of flows in nanochannels we use heavy water mass spectrometry. We construct the theory for the flow rates of the dominant modes of water transport through each of the four standard configurations and benchmark it against our new measurements in silica and against previously reported measurements for nanochannels in carbon nanotubes, carbon nanopipes, and porous alumina. The findings show that all behavior can be described by the four standard leak configurations and that measurements of leak behavior made using other molecules, such as helium, are not reliable. Single-phase water vapor flow is overestimated by a helium measurement, while two-phase flows are greatly underestimated for channels larger than 100 nm or for all channels when boundary slip applies, to an extent that depends on the slip length for the liquid-phase flows.

Evolutionary game theory for physical and biological scientists. I. Training and validating population dynamics equations.

Science.gov (United States)

Liao, David; Tlsty, Thea D

2014-08-06

Failure to understand evolutionary dynamics has been hypothesized as limiting our ability to control biological systems. An increasing awareness of similarities between macroscopic ecosystems and cellular tissues has inspired optimism that game theory will provide insights into the progression and control of cancer. To realize this potential, the ability to compare game theoretic models and experimental measurements of population dynamics should be broadly disseminated. In this tutorial, we present an analysis method that can be used to train parameters in game theoretic dynamics equations, used to validate the resulting equations, and used to make predictions to challenge these equations and to design treatment strategies. The data analysis techniques in this tutorial are adapted from the analysis of reaction kinetics using the method of initial rates taught in undergraduate general chemistry courses. Reliance on computer programming is avoided to encourage the adoption of these methods as routine bench activities.

Implicit ligand theory for relative binding free energies

Science.gov (United States)

Nguyen, Trung Hai; Minh, David D. L.

2018-03-01

Implicit ligand theory enables noncovalent binding free energies to be calculated based on an exponential average of the binding potential of mean force (BPMF)—the binding free energy between a flexible ligand and rigid receptor—over a precomputed ensemble of receptor configurations. In the original formalism, receptor configurations were drawn from or reweighted to the apo ensemble. Here we show that BPMFs averaged over a holo ensemble yield binding free energies relative to the reference ligand that specifies the ensemble. When using receptor snapshots from an alchemical simulation with a single ligand, the new statistical estimator outperforms the original.

Statistical test theory for the behavioral sciences

CERN Document Server

de Gruijter, Dato N M

2007-01-01

Since the development of the first intelligence test in the early 20th century, educational and psychological tests have become important measurement techniques to quantify human behavior. Focusing on this ubiquitous yet fruitful area of research, Statistical Test Theory for the Behavioral Sciences provides both a broad overview and a critical survey of assorted testing theories and models used in psychology, education, and other behavioral science fields. Following a logical progression from basic concepts to more advanced topics, the book first explains classical test theory, covering true score, measurement error, and reliability. It then presents generalizability theory, which provides a framework to deal with various aspects of test scores. In addition, the authors discuss the concept of validity in testing, offering a strategy for evidence-based validity. In the two chapters devoted to item response theory (IRT), the book explores item response models, such as the Rasch model, and applications, incl...

Some considerations for validation of repository performance assessment models

International Nuclear Information System (INIS)

Eisenberg, N.

1991-01-01

Validation is an important aspect of the regulatory uses of performance assessment. A substantial body of literature exists indicating the manner in which validation of models is usually pursued. Because performance models for a nuclear waste repository cannot be tested over the long time periods for which the model must make predictions, the usual avenue for model validation is precluded. Further impediments to model validation include a lack of fundamental scientific theory to describe important aspects of repository performance and an inability to easily deduce the complex, intricate structures characteristic of a natural system. A successful strategy for validation must attempt to resolve these difficulties in a direct fashion. Although some procedural aspects will be important, the main reliance of validation should be on scientific substance and logical rigor. The level of validation needed will be mandated, in part, by the uses to which these models are put, rather than by the ideal of validation of a scientific theory. Because of the importance of the validation of performance assessment models, the NRC staff has engaged in a program of research and international cooperation to seek progress in this important area. 2 figs., 16 refs

Communication Theory.

Science.gov (United States)

Penland, Patrick R.

Three papers are presented which delineate the foundation of theory and principles which underlie the research and instructional approach to communications at the Graduate School of Library and Information Science, University of Pittsburgh. Cybernetic principles provide the integration, and validation is based in part on a situation-producing…

Validation of a an analysis method of Marine Bio toxins Type Saxitoxin based on test coupled receptor (RBA) with Radiochemical Detection with liquid scintillation

International Nuclear Information System (INIS)

Selmi, Zied

2009-01-01

The saxitoxin s are bio toxins belonging to the family of toxins of the type PSP. They are paralysing toxins secreted by marine micro-organisms, phytoplankton, called Alexandrium. They constitute a risk for the human health in the event of their consumption in contaminated food. The acceptable maximum limit of these bio toxins in molluscs and shellfish is fixed to 800 μg /kg of meat of molluscs or shellfish. It proves, thus, that it is essential to develop and validate analytical methods for the level monitoring of contamination of the marine resources by these species in order to found a program of their monitoring and to guarantee an acceptable level of the food safety of the products available on the national and international markets. The present work allowed the validation of the quantification method of these toxins which is based on the use of the Receptor Binding Assay (RBA) with liquid scintillation nuclear technique detection using tritium as radiotracer and while proceeding by the different statistical tests of validation (Standard Nf XP T 90-210). The field of linearity ranged from 0 to 20 n M and the limit of detection was found to be 1 n M. The validation of this method will allow the reinforcement of the analytical means of analysis of marine bi toxins type SXT and to set up, in the near future, a monitoring and surveillance routine program for these bio toxins at the national, regional and African scales. (Author)

Measuring health workers' motivation composition: validation of a scale based on Self-Determination Theory in Burkina Faso.

Science.gov (United States)

Lohmann, Julia; Souares, Aurélia; Tiendrebéogo, Justin; Houlfort, Nathalie; Robyn, Paul Jacob; Somda, Serge M A; De Allegri, Manuela

2017-05-22

Although motivation of health workers in low- and middle-income countries (LMICs) has become a topic of increasing interest by policy makers and researchers in recent years, many aspects are not well understood to date. This is partly due to a lack of appropriate measurement instruments. This article presents evidence on the construct validity of a psychometric scale developed to measure motivation composition, i.e., the extent to which motivation of different origin within and outside of a person contributes to their overall work motivation. It is theoretically grounded in Self-Determination Theory (SDT). We conducted a cross-sectional survey of 1142 nurses in 522 government health facilities in 24 districts of Burkina Faso. We assessed the scale's validity in a confirmatory factor analysis framework, investigating whether the scale measures what it was intended to measure (content, structural, and convergent/discriminant validity) and whether it does so equally well across health worker subgroups (measurement invariance). Our results show that the scale measures a slightly modified version of the SDT continuum of motivation well. Measurements were overall comparable between subgroups, but results indicate that caution is warranted if a comparison of motivation scores between groups is the focus of analysis. The scale is a valuable addition to the repository of measurement tools for health worker motivation in LMICs. We expect it to prove useful in the quest for a more comprehensive understanding of motivation as well as of the effects and potential side effects of interventions intended to enhance motivation.

Water soluble and efficient amino acid Schiff base receptor for reversible fluorescence turn-on detection of Zn²⁺ ions: Quantum chemical calculations and detection of bacteria.

Science.gov (United States)

Subha, L; Balakrishnan, C; Natarajan, Satheesh; Theetharappan, M; Subramanian, Balanehru; Neelakantan, M A

2016-01-15

An amino acid Schiff base (R) capable of recognizing Zn(2+) ions selectively and sensitively in an aqueous medium was prepared and characterized. Upon addition of Zn(2+) ions, the receptor exhibits fluorescence intensity enhancements (~40 fold) at 460 nm (quantum yield, Φ=0.05 for R and Φ=0.18 for R-Zn(2+)) and can be detected by naked eye under UV light. The receptor can recognize the Zn(2+) (1.04×10(-8) M) selectively for other metal ions in the pH range of 7.5-11. The Zn(2+) chelation with R decreases the loss of energy through non-radiative transition and leads to fluorescence enhancement. The binding mode of the receptor with Zn(2+) was investigated by (1)H NMR titration and further validated by ESI-MS. The elemental color mapping and SEM/EDS analysis were also used to study the binding of R with Zn(2+). Density functional theory calculations were carried out to understand the binding mechanism. The receptor was applied as a microbial sensor for Escherichia coli and Staphylococcus aureus. Copyright © 2015 Elsevier B.V. All rights reserved.

39 The Validity of Herzberg's Dual-Factor Theory on Job Satisfaction ...

African Journals Online (AJOL)

User

2012-01-24

Jan 24, 2012 ... But Herzberg's two-factor theory (also called motivation /Hygiene theory) has been ... democratic process and more importantly, it attracts the right calibre of politicians into ..... Journal of Applied Psychology pp.162. Francis ...

Field theory and strings

International Nuclear Information System (INIS)

Bonara, L.; Cotta-Ramusino, P.; Rinaldi, M.

1987-01-01

It is well-known that type I and heterotic superstring theories have a zero mass spectrum which correspond to the field content of N=1 supergravity theory coupled to supersymmetric Yang-Mills theory in 10-D. The authors study the field theory ''per se'', in the hope that simple consistency requirements will determine the theory completely once one knows the field content inherited from string theory. The simplest consistency requirements are: N=1 supersymmetry; and absence of chiral anomalies. This is what the authors discuss in this paper here leaving undetermined the question of the range of validity of the resulting field theory. As is known, a model of N=1 supergravity (SUGRA) coupled to supersymmetric Yang-Mills (SYM) theory was known in the form given by Chapline and Manton. The coupling of SUGRA to SYM was determined by the definition of the ''field strength'' 3-form H in this paper

Nonstationary statistical theory for multipactor

International Nuclear Information System (INIS)

Anza, S.; Vicente, C.; Gil, J.; Boria, V. E.; Gimeno, B.; Raboso, D.

2010-01-01

This work presents a new and general approach to the real dynamics of the multipactor process: the nonstationary statistical multipactor theory. The nonstationary theory removes the stationarity assumption of the classical theory and, as a consequence, it is able to adequately model electron exponential growth as well as absorption processes, above and below the multipactor breakdown level. In addition, it considers both double-surface and single-surface interactions constituting a full framework for nonresonant polyphase multipactor analysis. This work formulates the new theory and validates it with numerical and experimental results with excellent agreement.

Development and Validation of the Sorokin Psychosocial Love Inventory for Divorced Individuals

Science.gov (United States)

D'Ambrosio, Joseph G.; Faul, Anna C.

2013-01-01

Objective: This study describes the development and validation of the Sorokin Psychosocial Love Inventory (SPSLI) measuring love actions toward a former spouse. Method: Classical measurement theory and confirmatory factor analysis (CFA) were utilized with an a priori theory and factor model to validate the SPSLI. Results: A 15-item scale…

Generalized second law of thermodynamic in modified teleparallel theory

Energy Technology Data Exchange (ETDEWEB)

Zubair, M. [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan); Bahamonde, Sebastian [University College London, Department of Mathematics, London (United Kingdom); Jamil, Mubasher [National University of Sciences and Technology (NUST), Department of Mathematics, School of Natural Sciences (SNS), Islamabad (Pakistan)

2017-07-15

This study is conducted to examine the validity of the generalized second law of thermodynamics (GSLT) in flat FRW for modified teleparallel gravity involving coupling between a scalar field with the torsion scalar T and the boundary term B = 2∇{sub μ}T{sup μ}. This theory is very useful, since it can reproduce other important well-known scalar field theories in suitable limits. The validity of the first and second law of thermodynamics at the apparent horizon is discussed for any coupling. As examples, we have also explored the validity of those thermodynamics laws in some new cosmological solutions under the theory. Additionally, we have also considered the logarithmic entropy corrected relation and discuss the GSLT at the apparent horizon. (orig.)

Generalized second law of thermodynamic in modified teleparallel theory

International Nuclear Information System (INIS)

Zubair, M.; Bahamonde, Sebastian; Jamil, Mubasher

2017-01-01

This study is conducted to examine the validity of the generalized second law of thermodynamics (GSLT) in flat FRW for modified teleparallel gravity involving coupling between a scalar field with the torsion scalar T and the boundary term B = 2∇ μ T μ . This theory is very useful, since it can reproduce other important well-known scalar field theories in suitable limits. The validity of the first and second law of thermodynamics at the apparent horizon is discussed for any coupling. As examples, we have also explored the validity of those thermodynamics laws in some new cosmological solutions under the theory. Additionally, we have also considered the logarithmic entropy corrected relation and discuss the GSLT at the apparent horizon. (orig.)

What Do You Think You Are Measuring? A Mixed-Methods Procedure for Assessing the Content Validity of Test Items and Theory-Based Scaling

Science.gov (United States)

Koller, Ingrid; Levenson, Michael R.; Glück, Judith

2017-01-01

The valid measurement of latent constructs is crucial for psychological research. Here, we present a mixed-methods procedure for improving the precision of construct definitions, determining the content validity of items, evaluating the representativeness of items for the target construct, generating test items, and analyzing items on a theoretical basis. To illustrate the mixed-methods content-scaling-structure (CSS) procedure, we analyze the Adult Self-Transcendence Inventory, a self-report measure of wisdom (ASTI, Levenson et al., 2005). A content-validity analysis of the ASTI items was used as the basis of psychometric analyses using multidimensional item response models (N = 1215). We found that the new procedure produced important suggestions concerning five subdimensions of the ASTI that were not identifiable using exploratory methods. The study shows that the application of the suggested procedure leads to a deeper understanding of latent constructs. It also demonstrates the advantages of theory-based item analysis. PMID:28270777

Automatic validation of numerical solutions

DEFF Research Database (Denmark)

Stauning, Ole

1997-01-01

This thesis is concerned with ``Automatic Validation of Numerical Solutions''. The basic theory of interval analysis and self-validating methods is introduced. The mean value enclosure is applied to discrete mappings for obtaining narrow enclosures of the iterates when applying these mappings...... differential equations, but in this thesis, we describe how to use the methods for enclosing iterates of discrete mappings, and then later use them for discretizing solutions of ordinary differential equations. The theory of automatic differentiation is introduced, and three methods for obtaining derivatives...... are described: The forward, the backward, and the Taylor expansion methods. The three methods have been implemented in the C++ program packages FADBAD/TADIFF. Some examples showing how to use the three metho ds are presented. A feature of FADBAD/TADIFF not present in other automatic differentiation packages...

Two theories on the test bench: Internal and external validity of the theories of Ronald Inglehart and Shalom Schwartz

OpenAIRE

Datler, Georg; Jagodzinski, Wolfgang; Schmidt, Peter

2013-01-01

In the last decades value research has produced a vast number of theoretical concepts. However, it is unclear how the different value theories relate to each other. This study makes a first step toward a systematic comparison of value theories. It focuses on the individual level of the two approaches that are, at present, probably the most prominent in international research - the theory of basic human values of Shalom Schwartz and the postmodernization theory of Ronald Inglehart. Using data ...

Validity of Purchasing Power Parity in BRICS under a DFA Approach

Directory of Open Access Journals (Sweden)

Emmanuel Numapau Gyamfi

2017-02-01

Full Text Available This study tests the validity of the purchasing power parity (PPP theory in Brazil, Russia, India, Macao-China and South Africa. We examine real exchange rates of these countries for mean reversion. The Hurst exponent is our mean reversion measure which is evaluated by the Detrended Fluctuation Analysis (DFA in a rolling window to determine the validity of the PPP theory amongst these countries through time. Our results show persistence in real exchange rates; an indication not supporting the PPP theory in the five countries. The study contributes to the extant literature of the PPP theory in BRICS using the DFA approach in a rolling window through time.

Molecular interactions of agonist and inverse agonist ligands at serotonin 5-HT2C G protein-coupled receptors: computational ligand docking and molecular dynamics studies validated by experimental mutagenesis results

Science.gov (United States)

Córdova-Sintjago, Tania C.; Liu, Yue; Booth, Raymond G.

2015-02-01

To understand molecular determinants for ligand activation of the serotonin 5-HT2C G protein-coupled receptor (GPCR), a drug target for obesity and neuropsychiatric disorders, a 5-HT2C homology model was built according to an adrenergic β2 GPCR (β2AR) structure and validated using a 5-HT2B GPCR crystal structure. The models were equilibrated in a simulated phosphatidyl choline membrane for ligand docking and molecular dynamics studies. Ligands included (2S, 4R)-(-)-trans-4-(3'-bromo- and trifluoro-phenyl)-N,N-dimethyl-1,2,3,4-tetrahydronaphthalene-2-amine (3'-Br-PAT and 3'-CF3-PAT), a 5-HT2C agonist and inverse agonist, respectively. Distinct interactions of 3'-Br-PAT and 3'-CF3-PAT at the wild-type (WT) 5-HT2C receptor model were observed and experimental 5-HT2C receptor mutagenesis studies were undertaken to validate the modelling results. For example, the inverse agonist 3'-CF3-PAT docked deeper in the WT 5-HT2C binding pocket and altered the orientation of transmembrane helices (TM) 6 in comparison to the agonist 3'-Br-PAT, suggesting that changes in TM orientation that result from ligand binding impact function. For both PATs, mutation of 5-HT2C residues S3.36, T3.37, and F5.47 to alanine resulted in significantly decreased affinity, as predicted from modelling results. It was concluded that upon PAT binding, 5-HT2C residues T3.37 and F5.47 in TMs 3 and 5, respectively, engage in inter-helical interactions with TMs 4 and 6, respectively. The movement of TMs 5 and 6 upon agonist and inverse agonist ligand binding observed in the 5-HT2C receptor modelling studies was similar to movements reported for the activation and deactivation of the β2AR, suggesting common mechanisms among aminergic neurotransmitter GPCRs.

How Developments in Psychology and Technology Challenge Validity Argumentation

Science.gov (United States)

Mislevy, Robert J.

2016-01-01

Validity is the sine qua non of properties of educational assessment. While a theory of validity and a practical framework for validation has emerged over the past decades, most of the discussion has addressed familiar forms of assessment and psychological framings. Advances in digital technologies and in cognitive and social psychology have…

Development and validation of the Brazilian version of the Attitudes to Aging Questionnaire (AAQ: An example of merging classical psychometric theory and the Rasch measurement model

Directory of Open Access Journals (Sweden)

Trentini Clarissa M

2008-01-01

Full Text Available Abstract Background Aging has determined a demographic shift in the world, which is considered a major societal achievement, and a challenge. Aging is primarily a subjective experience, shaped by factors such as gender and culture. There is a lack of instruments to assess attitudes to aging adequately. In addition, there is no instrument developed or validated in developing region contexts, so that the particularities of ageing in these areas are not included in the measures available. This paper aims to develop and validate a reliable attitude to aging instrument by combining classical psychometric approach and Rasch analysis. Methods Pilot study and field trial are described in details. Statistical analysis included classic psychometric theory (EFA and CFA and Rasch measurement model. The latter was applied to examine unidimensionality, response scale and item fit. Results Sample was composed of 424 Brazilian old adults, which was compared to an international sample (n = 5238. The final instrument shows excellent psychometric performance (discriminant validity, confirmatory factor analysis and Rasch fit statistics. Rasch analysis indicated that modifications in the response scale and item deletions improved the initial solution derived from the classic approach. Conclusion The combination of classic and modern psychometric theories in a complementary way is fruitful for development and validation of instruments. The construction of a reliable Brazilian Attitudes to Aging Questionnaire is important for assessing cultural specificities of aging in a transcultural perspective and can be applied in international cross-cultural investigations running less risk of cultural bias.

Facial morphometry of Ecuadorian patients with growth hormone receptor deficiency/Laron syndrome.

Science.gov (United States)

Schaefer, G B; Rosenbloom, A L; Guevara-Aguirre, J; Campbell, E A; Ullrich, F; Patil, K; Frias, J L

1994-01-01

Facial morphometry using computerised image analysis was performed on patients with growth hormone receptor deficiency (Laron syndrome) from an inbred population of southern Ecuador. Morphometrics were compared for 49 patients, 70 unaffected relatives, and 14 unrelated persons. Patients with growth hormone receptor deficiency showed significant decreases in measures of vertical facial growth as compared to unaffected relatives and unrelated persons with short stature from other causes. This report validates and quantifies the clinical impression of foreshortened facies in growth hormone receptor deficiency. Images PMID:7815422

Experimental validation of the Wigner distributions theory of phase-contrast imaging

International Nuclear Information System (INIS)

Donnelly, Edwin F.; Price, Ronald R.; Pickens, David R.

2005-01-01

Recently, a new theory of phase-contrast imaging has been proposed by Wu and Liu [Med. Phys. 31, 2378-2384 (2004)]. This theory, based upon Wigner distributions, provides a much stronger foundation for the evaluation of phase-contrast imaging systems than did the prior theories based upon Fresnel-Kirchhoff diffraction theory. In this paper, we compare results of measurements made in our laboratory of phase contrast for different geometries and tube voltages to the predictions of the Wu and Liu model. In our previous publications, we have used an empirical measurement (the edge enhancement index) to parametrize the degree of phase-contrast effects in an image. While the Wu and Liu model itself does not predict image contrast, it does measure the degree of phase contrast that the system can image for a given spatial frequency. We have found that our previously published experimental results relating phase-contrast effects to geometry and x-ray tube voltage are consistent with the predictions of the Wu and Liu model

Universality of sparse d>2 conformal field theory at large N

Energy Technology Data Exchange (ETDEWEB)

Belin, Alexandre; Boer, Jan de; Kruthoff, Jorrit [Institute for Theoretical Physics Amsterdam and Delta Institute for Theoretical Physics,University of Amsterdam, Science Park 904, Amsterdam, 1098 XH The (Netherlands); Michel, Ben; Shaghoulian, Edgar; Shyani, Milind [Department of Physics, University of California,Santa Barbara, CA, 93106 (United States)

2017-03-13

We derive necessary and sufficient conditions for large N conformal field theories to have a universal free energy and an extended range of validity of the higher-dimensional Cardy formula. These constraints are much tighter than in two dimensions and must be satisfied by any conformal field theory dual to Einstein gravity. We construct and analyze symmetric product orbifold theories on T{sup d} and show that they only realize the necessary phase structure and extended range of validity if the seed theory is assumed to have a universal vacuum energy.

Comparing theories' performance in predicting violence

OpenAIRE

Haas, Henriette; Cusson, Maurice

2015-01-01

The stakes of choosing the best theory as a basis for violence prevention and offender rehabilitation are high. However, no single theory of violence has ever been universally accepted by a majority of established researchers. Psychiatry, psychology and sociology are each subdivided into different schools relying upon different premises. All theories can produce empirical evidence for their validity, some of them stating the opposite of each other. Calculating different models wit...

Substance Use Stigma: Reliability and validity of a theory-based scale for substance-using populations*

Science.gov (United States)

Smith, Laramie R.; Earnshaw, Valerie A.; Copenhaver, Michael M.; Cunningham, Chinazo O.

2016-01-01

Background Substance use disorders consistently rank among the most stigmatized conditions worldwide. Thus, substance use stigma fosters health inequities among persons with substance use disorders and remains a key barrier to successful screening and treatment efforts. Current efforts to measure substance use stigma are limited. This study aims to advance measurement efforts by drawing on stigma theory to develop and evaluate the Substance Use Stigma Mechanisms Scale (SU-SMS). The SU-SMS was designed to capture enacted, anticipated, and internalized substance use stigma mechanisms among persons with current and past substance use disorders, and distinguish between key stigma sources most likely to impact this target population. Methods This study was a cross-sectional evaluation of the validity, reliability, and generalizability of the SU-SMS across two independent samples with diverse substance use and treatment histories. Results Findings support the structural and construct validity of the SU-SMS, suggesting the scale was able to capture enacted, anticipated, and internalized stigma as distinct stigma experiences. It also further differentiated between two distinct stigma sources (family and healthcare providers). Analysis of these mechanisms and psychosocial metrics suggests that the scale is also associated with other health-related outcomes. Furthermore, the SU-SMS demonstrated high levels of internal reliability and generalizability across two independent samples of persons with diverse substance use disorders and treatment histories. Conclusion The SU-SMS may serve as a valuable tool for better understanding the processes through which substance use stigma serves to undermine key health behaviors and outcomes among persons with substance use disorders. PMID:26972790

Beyond Modeling: All-Atom Olfactory Receptor Model Simulations

Directory of Open Access Journals (Sweden)

Peter C Lai

2012-05-01

Full Text Available Olfactory receptors (ORs are a type of GTP-binding protein-coupled receptor (GPCR. These receptors are responsible for mediating the sense of smell through their interaction with odor ligands. OR-odorant interactions marks the first step in the process that leads to olfaction. Computational studies on model OR structures can validate experimental functional studies as well as generate focused and novel hypotheses for further bench investigation by providing a view of these interactions at the molecular level. Here we have shown the specific advantages of simulating the dynamic environment that is associated with OR-odorant interactions. We present a rigorous methodology that ranges from the creation of a computationally-derived model of an olfactory receptor to simulating the interactions between an OR and an odorant molecule. Given the ubiquitous occurrence of GPCRs in the membranes of cells, we anticipate that our OR-developed methodology will serve as a model for the computational structural biology of all GPCRs.

Notes on the Verlinde formula in nonrational conformal field theories

International Nuclear Information System (INIS)

Jego, Charles; Troost, Jan

2006-01-01

We review and extend evidence for the validity of a generalized Verlinde formula, in particular, nonrational conformal field theories. We identify a subset of representations of the chiral algebra in nonrational conformal field theories that give rise to an analogue of the relation between modular S-matrices and fusion coefficients in rational conformal field theories. To that end we review and extend the Cardy-type brane calculations in bosonic and supersymmetric Liouville theory (and its duals) as well as in H 3 + . We analyze the three-point functions of Liouville theory and of H 3 + in detail to directly identify the fusion coefficients from the operator product expansion. Moreover, we check the validity of a proposed generic formula for localized brane one-point functions in nonrational conformal field theories

Graphical Model Theory for Wireless Sensor Networks

International Nuclear Information System (INIS)

Davis, William B.

2002-01-01

Information processing in sensor networks, with many small processors, demands a theory of computation that allows the minimization of processing effort, and the distribution of this effort throughout the network. Graphical model theory provides a probabilistic theory of computation that explicitly addresses complexity and decentralization for optimizing network computation. The junction tree algorithm, for decentralized inference on graphical probability models, can be instantiated in a variety of applications useful for wireless sensor networks, including: sensor validation and fusion; data compression and channel coding; expert systems, with decentralized data structures, and efficient local queries; pattern classification, and machine learning. Graphical models for these applications are sketched, and a model of dynamic sensor validation and fusion is presented in more depth, to illustrate the junction tree algorithm

Syndemics: A theory in search of data or data in search of a theory?

Science.gov (United States)

Tsai, Alexander C

2018-06-01

The concept of a syndemic was proposed more than two decades ago to explain how large-scale social forces might give rise to co-occurring epidemics that synergistically interact to undermine health in vulnerable populations. This conceptual instrument has the potential to help policymakers and program implementers in their endeavors to improve population health. Accordingly, it has become an increasingly popular heuristic for advocacy, most notably in the field of HIV treatment and prevention. However, most empirical studies purporting to validate the theory of syndemics actually do no such thing. Tomori et al. (2018) provide a novel case study from India illustrating how the dominant empirical approach fails to promote deeper understanding about how hazardous alcohol use, illicit drug use, depression, childhood sexual abuse, and intimate partner violence interact to worsen HIV risk among men who have sex with men. In this commentary, I relate the theory of syndemics to other established social science and public health theories of disease distribution, identify possible sources of conceptual and empirical confusion, and provide concrete suggestions for how to validate the theory using a mixed-methods approach. The hope is that more evidence can be mobilized -- whether informed by the theory of syndemics or not -- to improve health and psychosocial wellbeing among vulnerable populations worldwide. Copyright © 2018 Elsevier Ltd. All rights reserved.

Validation of the kinetic-turbulent-neoclassical theory for edge intrinsic rotation in DIII-D

Science.gov (United States)

Ashourvan, Arash; Grierson, B. A.; Battaglia, D. J.; Haskey, S. R.; Stoltzfus-Dueck, T.

2018-05-01

In a recent kinetic model of edge main-ion (deuterium) toroidal velocity, intrinsic rotation results from neoclassical orbits in an inhomogeneous turbulent field [T. Stoltzfus-Dueck, Phys. Rev. Lett. 108, 065002 (2012)]. This model predicts a value for the toroidal velocity that is co-current for a typical inboard X-point plasma at the core-edge boundary (ρ ˜ 0.9). Using this model, the velocity prediction is tested on the DIII-D tokamak for a database of L-mode and H-mode plasmas with nominally low neutral beam torque, including both signs of plasma current. Values for the flux-surface-averaged main-ion rotation velocity in the database are obtained from the impurity carbon rotation by analytically calculating the main-ion—impurity neoclassical offset. The deuterium rotation obtained in this manner has been validated by direct main-ion measurements for a limited number of cases. Key theoretical parameters of ion temperature and turbulent scale length are varied across a wide range in an experimental database of discharges. Using a characteristic electron temperature scale length as a proxy for a turbulent scale length, the predicted main-ion rotation velocity has a general agreement with the experimental measurements for neutral beam injection (NBI) powers in the range PNBI balanced—but high powered—NBI, the net injected torque through the edge can exceed 1 Nm in the counter-current direction. The theory model has been extended to compute the rotation degradation from this counter-current NBI torque by solving a reduced momentum evolution equation for the edge and found the revised velocity prediction to be in agreement with experiment. Using the theory modeled—and now tested—velocity to predict the bulk plasma rotation opens up a path to more confidently projecting the confinement and stability in ITER.

76 FR 62421 - Submission for OMB Review; Comment Request; A Generic Submission for Theory Development and...

Science.gov (United States)

2011-10-07

...; Comment Request; A Generic Submission for Theory Development and Validation (NCI) SUMMARY: Under the... control number. Proposed Collection: Title: A Generic Submission for Theory Development and Validation...), to conduct and support behavioral research informed by and informing theory. Formative research in...

The conceptualization and empirical validation of website user satisfaction

NARCIS (Netherlands)

Moenaert, R.K.; Muylle, S.; Despontin, M.

2004-01-01

This article addresses the concern for effective web site design by means of the conceptualization and empirical validation of a web site user satisfaction construct. Based on IS success theory, hypermedia design theory, a qualitative exploratory pilot study, and a quantitative online critical

Cotargeting of Androgen Synthesis and Androgen Receptor Expression as a Novel Treatment for Castration Resistant Prostate Cancer

Science.gov (United States)

2017-08-01

disease [2-4]. The major mechanism underlying the development of CRPC is the reactivation of the androgen receptor (AR), the driver of prostate cancer ...Epigenetic Activator of Androgen Receptor Expression in Castration- Resistant Prostate Cancer . Indiana Basic Urological Research (IBUR) Symposium...principal discipline(s) of the project? Androgen receptor (AR) is the driver of prostate cancer development and progression and is the validated

Validity of Management Control Topoi

DEFF Research Database (Denmark)

Nørreklit, Lennart; Nørreklit, Hanne; Israelsen, Poul

2004-01-01

The validity of research and company topoi for constructing/analyzing relaity is analyzed as the integration of the four aspects (dimensions): fact, possibility (logic), value and comunication. Main stream, agency theory and social constructivism are critizied for reductivism (incomplete integrat...

The Children's Social Understanding Scale: construction and validation of a parent-report measure for assessing individual differences in children's theories of mind.

Science.gov (United States)

Tahiroglu, Deniz; Moses, Louis J; Carlson, Stephanie M; Mahy, Caitlin E V; Olofson, Eric L; Sabbagh, Mark A

2014-11-01

Children's theory of mind (ToM) is typically measured with laboratory assessments of performance. Although these measures have generated a wealth of informative data concerning developmental progressions in ToM, they may be less useful as the sole source of information about individual differences in ToM and their relation to other facets of development. In the current research, we aimed to expand the repertoire of methods available for measuring ToM by developing and validating a parent-report ToM measure: the Children's Social Understanding Scale (CSUS). We present 3 studies assessing the psychometric properties of the CSUS. Study 1 describes item analysis, internal consistency, test-retest reliability, and relation of the scale to children's performance on laboratory ToM tasks. Study 2 presents cross-validation data for the scale in a different sample of preschool children with a different set of ToM tasks. Study 3 presents further validation data for the scale with a slightly older age group and a more advanced ToM task, while controlling for several other relevant cognitive abilities. The findings indicate that the CSUS is a reliable and valid measure of individual differences in children's ToM that may be of great value as a complement to standard ToM tasks in many different research contexts. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Question of Drug Workers under the Prism Theory of Axel Honneth recognition . Human Right to Work and his pretension of Universal Validity

OpenAIRE

Maria Cecília Máximo Teodoro; Sabrina Colares Nogueira

2016-01-01

Relate the theme regarding the Theory of Recognition Axel Honnet, the human right to work as a human right to claim to universal validity, from the perspective of the Declaration of Fundamental Principles and Rights at Work ILO, for purposes of setting parameters and recognition of social (re) integration of chemical class dependent workers is the main goal of this article. We will analyze the theoretical framework in which the pursuit of human dignity at work is the goal of the state to whic...

Experimental Validation of the Electrokinetic Theory and Development of Seismoelectric Interferometry by Cross-Correlation

Directory of Open Access Journals (Sweden)

F. C. Schoemaker

2012-01-01

Full Text Available We experimentally validate a relatively recent electrokinetic formulation of the streaming potential (SP coefficient as developed by Pride (1994. The start of our investigation focuses on the streaming potential coefficient, which gives rise to the coupling of mechanical and electromagnetic fields. It is found that the theoretical amplitude values of this dynamic SP coefficient are in good agreement with the normalized experimental results over a wide frequency range, assuming no frequency dependence of the bulk conductivity. By adopting the full set of electrokinetic equations, a full-waveform wave propagation model is formulated. We compare the model predictions, neglecting the interface response and modeling only the coseismic fields, with laboratory measurements of a seismic wave of frequency 500 kHz that generates electromagnetic signals. Agreement is observed between measurement and electrokinetic theory regarding the coseismic electric field. The governing equations are subsequently adopted to study the applicability of seismoelectric interferometry. It is shown that seismic sources at a single boundary location are sufficient to retrieve the 1D seismoelectric responses, both for the coseismic and interface components, in a layered model.

Latinas/os in Community College Developmental Education: Increasing Moments of Academic and Interpersonal Validation

Science.gov (United States)

Acevedo-Gil, Nancy; Santos, Ryan E.; Alonso, LLuliana; Solorzano, Daniel G.

2015-01-01

This qualitative study examines the experiences of Latinas/os in community college English and math developmental education courses. Critical race theory in education and the theory of validation serve as guiding frameworks. The authors find that institutional agents provide academic validation by emphasizing high expectations, focusing on social…

Structure and function of the IFNγ receptor on human mononuclear phagocytes

International Nuclear Information System (INIS)

Schreiber, R.D.; Celada, A.

1986-01-01

Human mononuclear phagocytes bear a receptor that binds 125 I-IFNγ in a saturable, reversible and specific manner. The receptor consists minimally of a 70 kD polypeptide chain and its expression (5000/cell) and binding affinity (Ka=10 9 M -1 ) are unaffected by cellular activation or differentiation. The receptor's biological relevance was validated by correlating receptor occupancy with induction of a cellular response. 50% maximal induction of Fc receptors on U937 was effected by 0.8 nM IFNγ; the same concentration needed to half saturate U937 IFNγ receptors. Ligand-receptor interaction displayed species specificity but not cellular specificity. The receptors on U937 and human fibroblasts displayed identical ligand binding affinities (1.5-1.8 x 10 9 M -1 ). At 37 0 C, IFNγ bound to U937 in a biphasic manner. The high affinity binding component was due to ligand internalization since purified cell membranes and paraformaldehyde fixed cells displayed only the lower Ka and ligand internalization could be directly demonstrated. Using lysosomotropic amines, the internalized IFNγ-IFNγ receptor complex was tracked into an acid compartment where dissociation occurred. Free intracellular IFNγ was then degraded while free receptor entered an intracellular pool and eventually recycled back to the cell surface

Validation of a proxy for estrogen receptor status in breast cancer patients using dispensing data.

Science.gov (United States)

Srasuebkul, Preeyaporn; Dobbins, Timothy A; Pearson, Sallie-Anne

2014-06-01

To assess the performance of a proxy for estrogen receptor (ER) status in breast cancer patients using dispensing data. We derived our proxy using 167 patients. ER+ patients had evidence of at least one dispensing record for hormone therapy during the lookback period, irrespective of diagnosis date and ER- had no dispensing records for hormone therapy during the period. We validated the proxy against our gold standard, ER status from pathology reports or medical records. We assessed the proxy's performance using three lookback periods: 4.5 years, 2 years, 1 year. More than half of our cohort (62%) were >50 years, 54% had stage III/IV breast cancer at recruitment, (46%) were diagnosed with breast cancer in 2009 and 23% were diagnosed before 2006. Sensitivity and specificity were high for the 4.5 year lookback period (93%, 95% CI: 86-96%; and 95%: 83-99%), respectively) and remained high for the 2-year lookback period (91%: 84-95%; and 95%: 83-99%). Sensitivity decreased (83%: 75.2-89%) but specificity remained high (95%: 83-99%) using the 1-year lookback period and the period is long enough to allow sufficient time for hormone therapy to be dispensed. Our proxy accurately infers ER status in studies of breast cancer treatment based on secondary health data. The proxy is most robust with a minimum lookback period of 2 years. © 2012 Wiley Publishing Asia Pty Ltd.

Beck's cognitive theory and the response style theory of depression in adolescents with and without mild to borderline intellectual disability

NARCIS (Netherlands)

Weeland, M.M.; Nijhof, K.S.; Otten, R.; Vermaes, I.P.R.; Buitelaar, J.K.

2017-01-01

Aim: This study tests the validity of Beck’s cognitive theory and Nolen-Hoeksema's response style theory of depression in adolescents with and without MBID. Methods: The relationship between negative cognitive errors (Beck), response styles (Nolen-Hoeksema) and depressive symptoms was examined in

Validating the predictions of case-based decision theory

OpenAIRE

Radoc, Benjamin

2015-01-01

Real-life decision-makers typically do not know all possible outcomes arising from alternative courses of action. Instead, when people face a problem, they may rely on the recollection of their past personal experience: the situation, the action taken, and the accompanying consequence. In addition, the applicability of a past experience in decision-making may depend on how similar the current problem is to situations encountered previously. Case-based decision theory (CBDT), proposed by Itzha...

Dopamine Receptor-Specific Contributions to the Computation of Value.

Science.gov (United States)

Burke, Christopher J; Soutschek, Alexander; Weber, Susanna; Raja Beharelle, Anjali; Fehr, Ernst; Haker, Helene; Tobler, Philippe N

2018-05-01

Dopamine is thought to play a crucial role in value-based decision making. However, the specific contributions of different dopamine receptor subtypes to the computation of subjective value remain unknown. Here we demonstrate how the balance between D1 and D2 dopamine receptor subtypes shapes subjective value computation during risky decision making. We administered the D2 receptor antagonist amisulpride or placebo before participants made choices between risky options. Compared with placebo, D2 receptor blockade resulted in more frequent choice of higher risk and higher expected value options. Using a novel model fitting procedure, we concurrently estimated the three parameters that define individual risk attitude according to an influential theoretical account of risky decision making (prospect theory). This analysis revealed that the observed reduction in risk aversion under amisulpride was driven by increased sensitivity to reward magnitude and decreased distortion of outcome probability, resulting in more linear value coding. Our data suggest that different components that govern individual risk attitude are under dopaminergic control, such that D2 receptor blockade facilitates risk taking and expected value processing.

Validating MEDIQUAL Constructs

Science.gov (United States)

Lee, Sang-Gun; Min, Jae H.

In this paper, we validate MEDIQUAL constructs through the different media users in help desk service. In previous research, only two end-users' constructs were used: assurance and responsiveness. In this paper, we extend MEDIQUAL constructs to include reliability, empathy, assurance, tangibles, and responsiveness, which are based on the SERVQUAL theory. The results suggest that: 1) five MEDIQUAL constructs are validated through the factor analysis. That is, importance of the constructs have relatively high correlations between measures of the same construct using different methods and low correlations between measures of the constructs that are expected to differ; and 2) five MEDIQUAL constructs are statistically significant on media users' satisfaction in help desk service by regression analysis.

Construct validity of the Moral Development Scale for Professionals (MDSP).

Science.gov (United States)

Söderhamn, Olle; Bjørnestad, John Olav; Skisland, Anne; Cliffordson, Christina

2011-01-01

The aim of this study was to investigate the construct validity of the Moral Development Scale for Professionals (MDSP) using structural equation modeling. The instrument is a 12-item self-report instrument, developed in the Scandinavian cultural context and based on Kohlberg's theory. A hypothesized simplex structure model underlying the MDSP was tested through structural equation modeling. Validity was also tested as the proportion of respondents older than 20 years that reached the highest moral level, which according to the theory should be small. A convenience sample of 339 nursing students with a mean age of 25.3 years participated. Results confirmed the simplex model structure, indicating that MDSP reflects a moral construct empirically organized from low to high. A minority of respondents >20 years of age (13.5%) scored more than 80% on the highest moral level. The findings support the construct validity of the MDSP and the stages and levels in Kohlberg's theory.

The formal and the formalized: the cases of syllogistic and supposition theory

NARCIS (Netherlands)

Dutilh Novaes, Catarina

2015-01-01

As a discipline, logic is arguably constituted of two main sub-projects: formal theories of argument validity on the basis of a small number of patterns, and theories of how to reduce the multiplicity of arguments in non-logical, informal contexts to the small number of patterns whose validity is

Using Rasch Analysis to Evaluate the Reliability and Validity of the Swallowing Quality of Life Questionnaire: An Item Response Theory Approach.

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Cordier, Reinie; Speyer, Renée; Schindler, Antonio; Michou, Emilia; Heijnen, Bas Joris; Baijens, Laura; Karaduman, Ayşe; Swan, Katina; Clavé, Pere; Joosten, Annette Veronica

2018-02-01

The Swallowing Quality of Life questionnaire (SWAL-QOL) is widely used clinically and in research to evaluate quality of life related to swallowing difficulties. It has been described as a valid and reliable tool, but was developed and tested using classic test theory. This study describes the reliability and validity of the SWAL-QOL using item response theory (IRT; Rasch analysis). SWAL-QOL data were gathered from 507 participants at risk of oropharyngeal dysphagia (OD) across four European countries. OD was confirmed in 75.7% of participants via videofluoroscopy and/or fiberoptic endoscopic evaluation, or a clinical diagnosis based on meeting selected criteria. Patients with esophageal dysphagia were excluded. Data were analysed using Rasch analysis. Item and person reliability was good for all the items combined. However, person reliability was poor for 8 subscales and item reliability was poor for one subscale. Eight subscales exhibited poor person separation and two exhibited poor item separation. Overall item and person fit statistics were acceptable. However, at an individual item fit level results indicated unpredictable item responses for 28 items, and item redundancy for 10 items. The item-person dimensionality map confirmed these findings. Results from the overall Rasch model fit and Principal Component Analysis were suggestive of a second dimension. For all the items combined, none of the item categories were 'category', 'threshold' or 'step' disordered; however, all subscales demonstrated category disordered functioning. Findings suggest an urgent need to further investigate the underlying structure of the SWAL-QOL and its psychometric characteristics using IRT.

Generalized algebra-valued models of set theory

NARCIS (Netherlands)

Löwe, B.; Tarafder, S.

2015-01-01

We generalize the construction of lattice-valued models of set theory due to Takeuti, Titani, Kozawa and Ozawa to a wider class of algebras and show that this yields a model of a paraconsistent logic that validates all axioms of the negation-free fragment of Zermelo-Fraenkel set theory.

Conception and validation of the Behavioral Intentions Scale of Organizational Citizenship (BISOC

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Ana Cristina Passos Gomes Menezes

2016-01-01

Full Text Available Abstract This study aimed to construct and validate the Behavioral Intentions of Organizational Citizenship Scale (BISOC. Organizational citizenship consists of measures of voluntary behaviors, which are beneficial to organizations and are not explicit in employment contracts. To investigate the psychometric properties of BISOC, we selected 767 employees in different cities from the states of Bahia and Pernambuco (Brazil. The validation procedures adopted, which used techniques from both Classical Test Theory and Item Response Theory, showed that the BISOC has a unidimensional structure. From the initial set of 42 items, 35 items met the validation criteria. By presenting suitable psychometric parameters, BISOC is the first measure of organizational citizenship behaviors developed and validated to assess behavioral intentions.

Cytologic assessment of estrogen receptor, progesterone receptor, and HER2 status in metastatic breast carcinoma.

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Pareja, Fresia; Murray, Melissa P; Jean, Ryan Des; Konno, Fumiko; Friedlander, Maria; Lin, Oscar; Edelweiss, Marcia

2017-01-01

Discordance in the receptor status between primary breast carcinomas (PBC) and corresponding metastasis is well documented. Interrogation of the receptor status of metastatic breast carcinoma (MBC) in cytology material is common practice; however, its utility has not been thoroughly validated. We studied patients with MBC, and evaluated the concordance rates of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) between PBC surgical specimens and corresponding MBC cell blocks (CBs). We correlated the findings with clinicopathologic variables and with the fixation methods used. We searched for patients with MBC diagnosed on cytology from 2007 to 2009 and selected those with ER, PR and HER2 tested in both the PBC surgical specimens and the MBC CBs. We included CBs fixed in formalin and methanol based solution (CytoLyt®). All slides were reevaluated by cytopathologists. Clinical information was retrieved from the medical records. We studied 65 patients with PBC and MBC paired specimens. The concordance rates between PBC and MBC were 78.5%, 58.5% and 96.9%, for ER, PR and HER2, respectively. When discordant, PR status switched from positive (PBC) to negative (MBC) in most cases (23/27). The PR concordance rate was 45.2% for CBs fixed in formalin and 70.6% for those fixed with CytoLyt® (p=0.047). The ER, PR and HER2 concordance rates between the PBC and MBC CBs are similar to those reported in paired surgical specimens. PR status was the most prevalent discordance and was not accompanied by a switch in ER.

Physiology and Emerging Biochemistry of the Glucagon-Like Peptide-1 Receptor

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Francis S. Willard

2012-01-01

Full Text Available The glucagon-like peptide-1 (GLP-1 receptor is one of the best validated therapeutic targets for the treatment of type 2 diabetes mellitus (T2DM. Over several years, the accumulation of basic, translational, and clinical research helped define the physiologic roles of GLP-1 and its receptor in regulating glucose homeostasis and energy metabolism. These efforts provided much of the foundation for pharmaceutical development of the GLP-1 receptor peptide agonists, exenatide and liraglutide, as novel medicines for patients suffering from T2DM. Now, much attention is focused on better understanding the molecular mechanisms involved in ligand induced signaling of the GLP-1 receptor. For example, advancements in biophysical and structural biology techniques are being applied in attempts to more precisely determine ligand binding and receptor occupancy characteristics at the atomic level. These efforts should better inform three-dimensional modeling of the GLP-1 receptor that will help inspire more rational approaches to identify and optimize small molecule agonists or allosteric modulators targeting the GLP-1 receptor. This article reviews GLP-1 receptor physiology with an emphasis on GLP-1 induced signaling mechanisms in order to highlight new molecular strategies that help determine desired pharmacologic characteristics for guiding development of future nonpeptide GLP-1 receptor activators.

Analytical Validation and Clinical Qualification of a New Immunohistochemical Assay for Androgen Receptor Splice Variant-7 Protein Expression in Metastatic Castration-resistant Prostate Cancer.

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Welti, Jonathan; Rodrigues, Daniel Nava; Sharp, Adam; Sun, Shihua; Lorente, David; Riisnaes, Ruth; Figueiredo, Ines; Zafeiriou, Zafeiris; Rescigno, Pasquale; de Bono, Johann S; Plymate, Stephen R

2016-10-01

The androgen receptor splice variant-7 (AR-V7) has been implicated in the development of castration-resistant prostate cancer (CRPC) and resistance to abiraterone and enzalutamide. To develop a validated assay for detection of AR-V7 protein in tumour tissue and determine its expression and clinical significance as patients progress from hormone-sensitive prostate cancer (HSPC) to CRPC. Following monoclonal antibody generation and validation, we retrospectively identified patients who had HSPC and CRPC tissue available for AR-V7 immunohistochemical (IHC) analysis. Nuclear AR-V7 expression was determined using IHC H score (HS) data. The change in nuclear AR-V7 expression from HSPC to CRPC and the association between nuclear AR-V7 expression and overall survival (OS) was determined. Nuclear AR-V7 expression was significantly lower in HSPC (median HS 50, interquartile range [IQR] 17.5-90) compared to CRPC (HS 135, IQR 80-157.5; pprostate cancer. A higher level of AR-V7 identifies a group of patients who respond less well to certain prostate cancer treatments and live for a shorter period of time. Copyright © 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Towards an analytical theory for charged hard spheres

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L.Blum

2007-09-01

Full Text Available Ion mixtures require an exclusion core to avoid collapse. The Debye Hueckel (DH theory, where ions are point charges, is accurate only in the limit of infinite dilution. The mean spherical approximation (MSA is the embedding of hard cores into DH, and is valid for higher densities. The properties of any ionic mixture can be represented by the single screening parameter Γ which for the equal ionic size restricted model is obtained from the Debye parameter κ. This Γ representation, the binding mean spherical approximation (BIMSA, is also valid for complex/associating systems, such as the general n-polyelectrolytes. The BIMSA is the only theory that satisfies the infinite dilution limit of the DH theory for any chain length. Furthermore, the contact pair distribution function calculated from our theory agrees with the Monte Carlo of Bresmeea. (Phys. Rev. E, 1995, 51, 289.

Anomalous energy exchange in the gBL and quasilinear theories

International Nuclear Information System (INIS)

Mynick, H.E.

1992-02-01

The rate of turbulence-induced energy exchange W o between species is computed in the framework of the quasilinear and gBL transport theories, and the relationship between these two theories, and the relationship between these two similar theories is thereby elucidated. For both theories, general formal expressions for W o are developed, and then applied to the trapped electron mode for illustration. The general expressions for W o in the two theories are formally closely related, but can yield predictions of very different magnitude in concrete applications. The fact that quasilinear theory is not valid for saturated steady-state turbulence gives rise to certain peculiarities in its predictions for this normal experimental situation, such as permitting energy to flow from the cooler to the hotter species, even in the limit of thermal equilibrium, where real-space gradients vanish. The gBL theory may be viewed as a modification of quasilinear theory to be valid for steady-state turbulence, keeping extra terms due to the self-consistent back reaction of particles on the fluctuations, which are just such as to eliminate these peculiarities

Benchmark validation of statistical models: Application to mediation analysis of imagery and memory.

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MacKinnon, David P; Valente, Matthew J; Wurpts, Ingrid C

2018-03-29

This article describes benchmark validation, an approach to validating a statistical model. According to benchmark validation, a valid model generates estimates and research conclusions consistent with a known substantive effect. Three types of benchmark validation-(a) benchmark value, (b) benchmark estimate, and (c) benchmark effect-are described and illustrated with examples. Benchmark validation methods are especially useful for statistical models with assumptions that are untestable or very difficult to test. Benchmark effect validation methods were applied to evaluate statistical mediation analysis in eight studies using the established effect that increasing mental imagery improves recall of words. Statistical mediation analysis led to conclusions about mediation that were consistent with established theory that increased imagery leads to increased word recall. Benchmark validation based on established substantive theory is discussed as a general way to investigate characteristics of statistical models and a complement to mathematical proof and statistical simulation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Is the Market Eroding Moral Norms? A Micro-analytical Validation of Some Ideas of Anomie Theory

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Eckhard Burkatzki

2008-11-01

Full Text Available Anomie theorists have been reporting the suppression of shared welfare orientations by the overwhelming dominance of economic values within capitalist societies since before the outset of neoliberalism debate. Obligations concerning common welfare are more and more often subordinated to the overarching aim of realizing economic success goals. This should be especially valid with for social life in contemporary market societies. This empirical investigation examines the extent to which market imperatives and values of the societal community are anchored within the normative orientations of market actors. Special attention is paid to whether the shape of these normative orientations varies with respect to the degree of market inclusion. Empirical analyses, based on the data of a standardized written survey within the German working population carried out in 2002, show that different types of normative orientation can be distinguished among market actors. These types are quite similar to the well-known types of anomic adaptation developed by Robert K. Merton in “Social Structure and Anomie” and are externally valid with respect to the prediction of different forms of economic crime. Further analyses show that the type of normative orientation actors adopt within everyday life depends on the dregree of market inclusion. Confirming anomie theory, it is shown that the individual willingness to subordinate matters of common welfare to the aim of economic success—radical market activism—gets stronger the more actors are included in the market sphere. Finally, the relevance of reported findings for the explanation of violent behavior, especially with view to varieties of corporate violence, is discussed.

Theory of mind in remitted bipolar disorder: Younger patients struggle in tasks of higher ecological validity.

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Feyerabend, Julia; Lüttke, Stefan; Grosse-Wentrup, Fabienne; Wolter, Sibylla; Hautzinger, Martin; Wolkenstein, Larissa

2018-04-15

To date, research concerning Theory of Mind (ToM) in remitted bipolar disorder (rBD) has yielded inconclusive results. This may be a result of methodological shortcomings and the failure to consider relevant third variables. Furthermore, studies using ecologically valid stimuli are rare. This study examines ToM in rBD patients, using ecologically valid stimuli. Additionally, the effects of sad mood induction (MI) as well as of age and gender are considered. The sample comprises N = 44 rBD patients (rBDPs) and N = 40 healthy controls (HCs). ToM decoding is assessed using the Cambridge Mindreading Face-Voice-Battery (CAM) and ToM reasoning using the Movie for the Assessment of Social Cognition (MASC). Both tasks were divided into two parts to conduct one part with and one without MI. While across the whole sample there was no evidence that rBDPs and HCs differed in ToM decoding or reasoning, in the younger subsample (age < 45) rBDPs performed worse than HCs in ToM decoding. While MI negatively influenced reasoning in both groups, gender had no effect. Most patients in this study had a high level of social functioning, limiting the generalizability of the results. As important social steps have to be undertaken before middle-age, the decoding deficits in younger rBDPs might be of particular importance not only for social functioning but also for the course of illness. Furthermore, this age-related deficit may explain the inconclusive findings that have been reported so far. Copyright © 2018 Elsevier B.V. All rights reserved.

The predictive validity of prospect theory versus expected utility in health utility measurement.

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Abellan-Perpiñan, Jose Maria; Bleichrodt, Han; Pinto-Prades, Jose Luis

2009-12-01

Most health care evaluations today still assume expected utility even though the descriptive deficiencies of expected utility are well known. Prospect theory is the dominant descriptive alternative for expected utility. This paper tests whether prospect theory leads to better health evaluations than expected utility. The approach is purely descriptive: we explore how simple measurements together with prospect theory and expected utility predict choices and rankings between more complex stimuli. For decisions involving risk prospect theory is significantly more consistent with rankings and choices than expected utility. This conclusion no longer holds when we use prospect theory utilities and expected utilities to predict intertemporal decisions. The latter finding cautions against the common assumption in health economics that health state utilities are transferable across decision contexts. Our results suggest that the standard gamble and algorithms based on, should not be used to value health.

Quantal foundation of the nucleon exchange transport theory

International Nuclear Information System (INIS)

Randrup, J.

1985-07-01

The central elements of the nucleon exchange transport theory are discussed within a fully quantal framework in order to elucidate the principal characteristics, validity and limitations of the theory. Special consideration is given to the mean rate of energy dissipation and the penetrability coefficient. (orig.)

Validation of an Instrument for Assessing Conceptual Change with Respect to the Theory of Evolution by Secondary Biology Students

Science.gov (United States)

Goff, Kevin David

This pilot study evaluated the validity of a new quantitative, closed-response instrument for assessing student conceptual change regarding the theory of evolution. The instrument has two distinguishing design features. First, it is designed not only to gauge student mastery of the scientific model of evolution, but also to elicit a trio of deeply intuitive tendencies that are known to compromise many students' understanding: the projection of intentional agency, teleological directionality, and immutable essences onto biological phenomena. Second, in addition to a section of conventional multiple choice questions, the instrument contains a series of items where students may simultaneously endorse both scientifically normative propositions and intuitively appealing yet unscientific propositions, without having to choose between them. These features allow for the hypothesized possibility that the three intuitions are partly innate, themselves products of cognitive evolution in our hominin ancestors, and thus may continue to inform students' thinking even after instruction and conceptual change. The test was piloted with 340 high school students from diverse schools and communities. Confirmatory factor analysis and other statistical methods provided evidence that the instrument already has strong potential for validly distinguishing students who hold a correct scientific understanding from those who do not, but that revision and retesting are needed to render it valid for gauging students' adherence to intuitive misconceptions. Ultimately the instrument holds promise as a tool for classroom intervention studies by conceptual change researchers, for diagnostic testing and data gathering by instructional leaders, and for provoking classroom dialogue and debate by science teachers.

Role of ethylene receptors during senescence and ripening in horticultural crops

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Agarwal, Gaurav; Choudhary, Divya; Singh, Virendra P.; Arora, Ajay

2012-01-01

The past two decades have been rewarding in terms of deciphering the ethylene signal transduction and functional validation of the ethylene receptor and downstream genes involved in the cascade. Our knowledge of ethylene receptors and its signal transduction pathway provides us a robust platform where we can think of manipulating and regulating ethylene sensitivity by the use of genetic engineering and making transgenic. This review focuses on ethylene perception, receptor mediated regulation of ethylene biosynthesis, role of ethylene receptors in flower senescence, fruit ripening and other effects induced by ethylene. The expression behavior of the receptor and downstream molecules in climacteric and non climacteric crops is also elaborated upon. Possible strategies and recent advances in altering the ethylene sensitivity of plants using ethylene receptor genes in an attempt to modulate the regulation and sensitivity to ethylene have also been discussed. Not only will these transgenic plants be a boon to post-harvest physiology and crop improvement but, it will also help us in discovering the mechanism of regulation of ethylene sensitivity. PMID:22751331

Gauge theory of amorphous magnets

International Nuclear Information System (INIS)

Nesterov, A.I.; Ovchinnikov, S.G.

1989-01-01

A gauge theory of disordered magnets as a field theory in the principal fiber bundle with structure group SL(3, R) is constructed. The gauge field interacting with a vector field (the magnetization) is responsible for the disorder. A complete system of equations, valid for arbitrary disordered magnets, is obtained. In the limiting case of a free gauge field the proposed approach leads to the well-known Volovik-Dzyaloshinskii theory, which describes isotropic spin glasses. In the other limiting case when the curvature is zero the results of Ignatchenko and Iskhakov for weakly disordered ferromagnets are reproduced

Differential Weighting of Items to Improve University Admission Test Validity

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Eduardo Backhoff Escudero

2001-05-01

Full Text Available This paper gives an evaluation of different ways to increase university admission test criterion-related validity, by differentially weighting test items. We compared four methods of weighting multiple-choice items of the Basic Skills and Knowledge Examination (EXHCOBA: (1 punishing incorrect responses by a constant factor, (2 weighting incorrect responses, considering the levels of error, (3 weighting correct responses, considering the item’s difficulty, based on the Classic Measurement Theory, and (4 weighting correct responses, considering the item’s difficulty, based on the Item Response Theory. Results show that none of these methods increased the instrument’s predictive validity, although they did improve its concurrent validity. It was concluded that it is appropriate to score the test by simply adding up correct responses.

Molecular pharmacology of promiscuous seven transmembrane receptors sensing organic nutrients.

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Wellendorph, Petrine; Johansen, Lars Dan; Bräuner-Osborne, Hans

2009-09-01

A number of highly promiscuous seven transmembrane (7TM) receptors have been cloned and characterized within the last few years. It is noteworthy that many of these receptors are activated broadly by amino acids, proteolytic degradation products, carbohydrates, or free fatty acids and are expressed in taste tissue, the gastrointestinal tract, endocrine glands, adipose tissue, and/or kidney. These receptors thus hold the potential to act as sensors of food intake, regulating, for example, release of incretin hormones from the gut, insulin/glucagon from the pancreas, and leptin from adipose tissue. The promiscuous tendency in ligand recognition of these receptors is in contrast to the typical specific interaction with one physiological agonist seen for most receptors, which challenges the classic "lock-and-key" concept. We here review the molecular mechanisms of nutrient sensing of the calcium-sensing receptor, the G protein-coupled receptor family C, group 6, subtype A (GPRC6A), and the taste1 receptor T1R1/T1R3, which are sensing L-alpha-amino acids, the carbohydrate-sensing T1R2/T1R3 receptor, the proteolytic degradation product sensor GPR93 (also termed GPR92), and the free fatty acid (FFA) sensing receptors FFA1, FFA2, FFA3, GPR84, and GPR120. The involvement of the individual receptors in sensing of food intake has been validated to different degrees because of limited availability of specific pharmacological tools and/or receptor knockout mice. However, as a group, the receptors represent potential drug targets, to treat, for example, type II diabetes by mimicking food intake by potent agonists or positive allosteric modulators. The ligand-receptor interactions of the promiscuous receptors of organic nutrients thus remain an interesting subject of emerging functional importance.

Investigating Postgraduate College Admission Interviews: Generalizability Theory Reliability and Incremental Predictive Validity

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Arce-Ferrer, Alvaro J.; Castillo, Irene Borges

2007-01-01

The use of face-to-face interviews is controversial for college admissions decisions in light of the lack of availability of validity and reliability evidence for most college admission processes. This study investigated reliability and incremental predictive validity of a face-to-face postgraduate college admission interview with a sample of…

Validation of antibodies for neuroanatomical localization of the P2Y receptor in macaque brain

DEFF Research Database (Denmark)

Dreisig, Karin; Degn, Matilda; Sund, Louise

2016-01-01

Focus on the purinergic receptor P2Y11 has increased following the finding of an association between the sleep disorder narcolepsy and a genetic variant in P2RY11 causing decreased gene expression. Narcolepsy is believed to arise from an autoimmune destruction of the hypothalamic neurons that pro......Focus on the purinergic receptor P2Y11 has increased following the finding of an association between the sleep disorder narcolepsy and a genetic variant in P2RY11 causing decreased gene expression. Narcolepsy is believed to arise from an autoimmune destruction of the hypothalamic neurons...

Test-retest paradigm of the forced swimming test in female mice is not valid for predicting antidepressant-like activity: participation of acetylcholine and sigma-1 receptors.

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Su, Jing; Hato-Yamada, Noriko; Araki, Hiroaki; Yoshimura, Hiroyuki

2013-01-01

The forced swimming test (FST) in mice is widely used to predict the antidepressant activity of a drug, but information describing the immobility of female mice is limited. We investigated whether a prior swimming experience affects the immobility duration in a second FST in female mice and whether the test-retest paradigm is a valid screening tool for antidepressants. Female ICR mice were exposed to the FST using two experimental paradigms: a single FST and a double FST in which mice had experienced FST once 24 h prior to the second trail. The initial FST experience reliably prolonged immobility duration in the second FST. The antidepressants imipramine and paroxetine significantly reduced immobility duration in the single FST, but not in the double FST. Scopolamine and the sigma-1 (σ1) antagonist NE-100 administered before the second trial significantly prevented the prolongation of immobility. Neither a 5-HT1A nor a 5-HT2A receptor agonist affected immobility duration. We suggest that the test-retest paradigm in female mice is not adequate for predicting antidepressant-like activity of a drug; the prolongation of immobility in the double FST is modulated through acetylcholine and σ1 receptors.

Computer arithmetic and validity theory, implementation, and applications

CERN Document Server

Kulisch, Ulrich

2013-01-01

This is the revised and extended second edition of the successful basic book on computer arithmetic. It is consistent with the newest recent standard developments in the field. The book shows how the arithmetic capability of the computer can be enhanced. The work is motivated by the desire and the need to improve the accuracy of numerical computing and to control the quality of the computed results (validity). The accuracy requirements for the elementary floating-point operations are extended to the customary product spaces of computations including interval spaces. The mathematical properties

Scale indicators of social exchange relationships: a comparison of relative content validity.

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Colquitt, Jason A; Baer, Michael D; Long, David M; Halvorsen-Ganepola, Marie D K

2014-07-01

Although social exchange theory has become one of the most oft-evoked theories in industrial and organizational psychology, there remains no consensus about how to measure its key mechanism: social exchange relationships (Blau, 1964). Drawing on Cropanzano and Byrne's (2000) review of contemporary social exchange theorizing, we examined the content validity of perceived support, exchange quality, affective commitment, trust, and psychological contract fulfillment as indicators of social exchange relationships. We used Hinkin and Tracey's (1999) quantitative approach to content validation, which asks participants to rate the correspondence between scale items and definitions of intended (and unintended) constructs. Our results revealed that some of the most frequently utilized indicators of social exchange relationships--perceived support and exchange quality--were significantly less content valid than rarely used options like affect-based trust. Our results also revealed that 2 direct measures--Bernerth, Armenakis, Feild, Giles, and Walker's (2007) scale and a scale created for this study--were content valid. We discuss the implications of these results for future applications of social exchange theory.

Assessment of a robust model protocol with accelerated throughput for a human recombinant full length estrogen receptor-alpha binding assay: protocol optimization and intralaboratory assay performance as initial steps towards validation.

Science.gov (United States)

Freyberger, Alexius; Wilson, Vickie; Weimer, Marc; Tan, Shirlee; Tran, Hoai-Son; Ahr, Hans-Jürgen

2010-08-01

Despite about two decades of research in the field of endocrine active compounds, still no validated human recombinant (hr) estrogen receptor-alpha (ERalpha) binding assay is available, although hr-ERalpha is available from several sources. In a joint effort, US EPA and Bayer Schering Pharma with funding from the EU-sponsored 6th framework project, ReProTect, developed a model protocol for such a binding assay. Important features of this assay are the use of a full length hr-ERalpha and performance in a 96-well plate format. A full length hr-ERalpha was chosen, as it was considered to provide the most accurate and human-relevant results, whereas truncated receptors could perform differently. Besides three reference compounds [17beta-estradiol, norethynodrel, dibutylphthalate] nine test compounds with different affinities for the ERalpha [diethylstilbestrol (DES), ethynylestradiol, meso-hexestrol, equol, genistein, o,p'-DDT, nonylphenol, n-butylparaben, and corticosterone] were used to explore the performance of the assay. Three independent experiments per compound were performed on different days, and dilutions of test compounds from deep-frozen stocks, solutions of radiolabeled ligand and receptor preparation were freshly prepared for each experiment. The ERalpha binding properties of reference and test compounds were well detected. As expected dibutylphthalate and corticosterone were non-binders in this assay. In terms of the relative ranking of binding affinities, there was good agreement with published data obtained from experiments using a human recombinant ERalpha ligand binding domain. Irrespective of the chemical nature of the compound, individual IC(50)-values for a given compound varied by not more than a factor of 2.5. Our data demonstrate that the assay was robust and reliably ranked compounds with strong, weak, and no affinity for the ERalpha with high accuracy. It avoids the manipulation and use of animals, i.e., the preparation of uterine cytosol as

Status of the Vibrational Theory of Olfaction

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Hoehn, Ross D.; Nichols, David E.; Neven, Hartmut; Kais, Sabre

2018-03-01

The vibrational theory of olfaction is an attempt to describe a possible mechanism for olfaction which is explanatory and provides researchers with a set of principles which permit predictions allowing for structure-odor relations. Similar theories have occurred several times throughout olfactory science; this theory has again recently come to prominence by Luca Turin who suggested that inelastic electron tunneling is the method by which vibrations are detected by the olfactory receptors within the hose. This work is intended to convey to the reader the an up-to-date account of the vibrational theory of olfaction, both the historical iterations as well as the present iteration. This text is designed to give a chronological account of both theoretical and experimental studies on the topic, while providing context, comments and background where they were found to be needed.

Nootropic α7 nicotinic receptor allosteric modulator derived from GABAA receptor modulators

Science.gov (United States)

Ng, Herman J.; Whittemore, Edward R.; Tran, Minhtam B.; Hogenkamp, Derk J.; Broide, Ron S.; Johnstone, Timothy B.; Zheng, Lijun; Stevens, Karen E.; Gee, Kelvin W.

2007-01-01

Activation of brain α7 nicotinic acetylcholine receptors (α7 nAChRs) has broad therapeutic potential in CNS diseases related to cognitive dysfunction, including Alzheimer's disease and schizophrenia. In contrast to direct agonist activation, positive allosteric modulation of α7 nAChRs would deliver the clinically validated benefits of allosterism to these indications. We have generated a selective α7 nAChR-positive allosteric modulator (PAM) from a library of GABAA receptor PAMs. Compound 6 (N-(4-chlorophenyl)-α-[[(4-chloro-phenyl)amino]methylene]-3-methyl-5-isoxazoleacet-amide) evokes robust positive modulation of agonist-induced currents at α7 nAChRs, while preserving the rapid native characteristics of desensitization, and has little to no efficacy at other ligand-gated ion channels. In rodent models, it corrects sensory-gating deficits and improves working memory, effects consistent with cognitive enhancement. Compound 6 represents a chemotype for allosteric activation of α7 nAChRs, with therapeutic potential in CNS diseases with cognitive dysfunction. PMID:17470817

A unified approach to validation, reliability, and education study design for surgical technical skills training.

Science.gov (United States)

Sweet, Robert M; Hananel, David; Lawrenz, Frances

2010-02-01

To present modern educational psychology theory and apply these concepts to validity and reliability of surgical skills training and assessment. In a series of cross-disciplinary meetings, we applied a unified approach of behavioral science principles and theory to medical technical skills education given the recent advances in the theories in the field of behavioral psychology and statistics. While validation of the individual simulation tools is important, it is only one piece of a multimodal curriculum that in and of itself deserves examination and study. We propose concurrent validation throughout the design of simulation-based curriculum rather than once it is complete. We embrace the concept that validity and curriculum development are interdependent, ongoing processes that are never truly complete. Individual predictive, construct, content, and face validity aspects should not be considered separately but as interdependent and complementary toward an end application. Such an approach could help guide our acceptance and appropriate application of these exciting new training and assessment tools for technical skills training in medicine.

Theory of coherent resonance energy transfer

International Nuclear Information System (INIS)

Jang, Seogjoo; Cheng, Y.-C.; Reichman, David R.; Eaves, Joel D.

2008-01-01

A theory of coherent resonance energy transfer is developed combining the polaron transformation and a time-local quantum master equation formulation, which is valid for arbitrary spectral densities including common modes. The theory contains inhomogeneous terms accounting for nonequilibrium initial preparation effects and elucidates how quantum coherence and nonequilibrium effects manifest themselves in the coherent energy transfer dynamics beyond the weak resonance coupling limit of the Foerster and Dexter (FD) theory. Numerical tests show that quantum coherence can cause significant changes in steady state donor/acceptor populations from those predicted by the FD theory and illustrate delicate cooperation of nonequilibrium and quantum coherence effects on the transient population dynamics.

Validity evidence based on test content.

Science.gov (United States)

Sireci, Stephen; Faulkner-Bond, Molly

2014-01-01

Validity evidence based on test content is one of the five forms of validity evidence stipulated in the Standards for Educational and Psychological Testing developed by the American Educational Research Association, American Psychological Association, and National Council on Measurement in Education. In this paper, we describe the logic and theory underlying such evidence and describe traditional and modern methods for gathering and analyzing content validity data. A comprehensive review of the literature and of the aforementioned Standards is presented. For educational tests and other assessments targeting knowledge and skill possessed by examinees, validity evidence based on test content is necessary for building a validity argument to support the use of a test for a particular purpose. By following the methods described in this article, practitioners have a wide arsenal of tools available for determining how well the content of an assessment is congruent with and appropriate for the specific testing purposes.

A generalized DEMATEL theory with a shrinkage coefficient for an indirect relation matrix

Directory of Open Access Journals (Sweden)

Liu Hsiang-Chuan

2017-01-01

Full Text Available In this paper, a novel decision-making trial and evaluation laboratory (DEMATEL theory with a shrinkage coefficient of indirect relation matrix is proposed, and a useful validity index, called Liu’s validity index, is also proposed for evaluating the performance of any DEMATEL model. If the shrinkage coefficient of an indirect relation matrix is equal to 1, then this new theory is identical to the traditional theory; in other words, it is a generalization of the traditional theory. Furthermore, the indirect relation is always considerably greater than the direct one in traditional DEMATEL theory, which is unreasonable and unfair because it overemphasizes the influence of the indirect relation. We prove in this paper that if the shrinkage coefficient is equal to 0.5, then the indirect relation is less than its direct relation. Because the shrinkage coefficient belongs to [0.5, 1], according to Liu’s validity index, we can find a more appropriate shrinkage coefficient to obtain a more efficient DEMATEL method. Some crucial properties of this new theory are discussed, and a simple example is provided to illustrate the advantages of the proposed theory.

What If Quantum Theory Violates All Mathematics?

Directory of Open Access Journals (Sweden)

Rosinger Elemér Elad

2017-09-01

Full Text Available It is shown by using a rather elementary argument in Mathematical Logic that if indeed, quantum theory does violate the famous Bell Inequalities, then quantum theory must inevitably also violate all valid mathematical statements, and in particular, such basic algebraic relations like 0 = 0, 1 = 1, 2 = 2, 3 = 3, … and so on …

Holographic effective field theories

Energy Technology Data Exchange (ETDEWEB)

Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei' , Università di Padova,and INFN - Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Zaffaroni, Alberto [Dipartimento di Fisica, Università di Milano-Bicocca,and INFN - Sezione di Milano-Bicocca, I-20126 Milano (Italy)

2016-06-28

We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.

5D-QSAR for spirocyclic sigma1 receptor ligands by Quasar receptor surface modeling.

Science.gov (United States)

Oberdorf, Christoph; Schmidt, Thomas J; Wünsch, Bernhard

2010-07-01

Based on a contiguous and structurally as well as biologically diverse set of 87 sigma(1) ligands, a 5D-QSAR study was conducted in which a quasi-atomistic receptor surface modeling approach (program package Quasar) was applied. The superposition of the ligands was performed with the tool Pharmacophore Elucidation (MOE-package), which takes all conformations of the ligands into account. This procedure led to four pharmacophoric structural elements with aromatic, hydrophobic, cationic and H-bond acceptor properties. Using the aligned structures a 3D-model of the ligand binding site of the sigma(1) receptor was obtained, whose general features are in good agreement with previous assumptions on the receptor structure, but revealed some novel insights since it represents the receptor surface in more detail. Thus, e.g., our model indicates the presence of an H-bond acceptor moiety in the binding site as counterpart to the ligands' cationic ammonium center, rather than a negatively charged carboxylate group. The presented QSAR model is statistically valid and represents the biological data of all tested compounds, including a test set of 21 ligands not used in the modeling process, with very good to excellent accuracy [q(2) (training set, n=66; leave 1/3 out) = 0.84, p(2) (test set, n=21)=0.64]. Moreover, the binding affinities of 13 further spirocyclic sigma(1) ligands were predicted with reasonable accuracy (mean deviation in pK(i) approximately 0.8). Thus, in addition to novel insights into the requirements for binding of spirocyclic piperidines to the sigma(1) receptor, the presented model can be used successfully in the rational design of new sigma(1) ligands. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Receptor-receptor interactions within receptor mosaics. Impact on neuropsychopharmacology.

Science.gov (United States)

Fuxe, K; Marcellino, D; Rivera, A; Diaz-Cabiale, Z; Filip, M; Gago, B; Roberts, D C S; Langel, U; Genedani, S; Ferraro, L; de la Calle, A; Narvaez, J; Tanganelli, S; Woods, A; Agnati, L F

2008-08-01

Future therapies for diseases associated with altered dopaminergic signaling, including Parkinson's disease, schizophrenia and drug addiction or drug dependence may substantially build on the existence of intramembrane receptor-receptor interactions within dopamine receptor containing receptor mosaics (RM; dimeric or high-order receptor oligomers) where it is believed that the dopamine D(2) receptor may operate as the 'hub receptor' within these complexes. The constitutive adenosine A(2A)/dopamine D(2) RM, located in the dorsal striato-pallidal GABA neurons, are of particular interest in view of the demonstrated antagonistic A(2A)/D(2) interaction within these heteromers; an interaction that led to the suggestion and later demonstration that A(2A) antagonists could be used as novel anti-Parkinsonian drugs. Based on the likely existence of A(2A)/D(2)/mGluR5 RM located both extrasynaptically on striato-pallidal GABA neurons and on cortico-striatal glutamate terminals, multiple receptor-receptor interactions within this RM involving synergism between A(2A)/mGluR5 to counteract D(2) signaling, has led to the proposal of using combined mGluR5 and A(2A) antagonists as a future anti-Parkinsonian treatment. Based on the same RM in the ventral striato-pallidal GABA pathways, novel strategies for the treatment of schizophrenia, building on the idea that A(2A) agonists and/or mGluR5 agonists will help reduce the increased dopaminergic signaling associated with this disease, have been suggested. Such treatment may ensure the proper glutamatergic drive from the mediodorsal thalamic nucleus to the prefrontal cortex, one which is believed to be reduced in schizophrenia due to a dominance of D(2)-like signaling in the ventral striatum. Recently, A(2A) receptors also have been shown to counteract the locomotor and sensitizing actions of cocaine and increases in A(2A) receptors have also been observed in the nucleus accumbens after extended cocaine self-administration, probably

The General Necessary Condition for the Validity of Dirac's Transition Perturbation Theory

Science.gov (United States)

Quang, Nguyen Vinh

1996-01-01

For the first time, from the natural requirements for the successive approximation the general necessary condition of validity of the Dirac's method is explicitly established. It is proved that the conception of 'the transition probability per unit time' is not valid. The 'super-platinium rules' for calculating the transition probability are derived for the arbitrarily strong time-independent perturbation case.

Examining the validity of the Academic Motivation Scale by comparing scale construction to self-determination theory.

Science.gov (United States)

Cokley, K O

2000-04-01

This study examined the construct validity of the Academic Motivation Scale. Specifically, subscale correlations were examined to assess whether support for a continuum of self-determination would be provided. The three types of Intrinsic Motivation were significantly and positively correlated with each other .67, .62, and .58, while the three types of Extrinsic Motivation were significantly and positively intercorrelated .50, .49, and .45. The former subscales, however, correlated higher with Introjected Regulation than Identified Regulation, suggesting that Introjected Regulation may be indicative of more self-determined behavior than has previously been believed. Also, the Intrinsic Motivation To Accomplish subscale had a stronger relationship with two of the Extrinsic Motivation subscales, Identified Regulation and Introjected Regulation, than did the Extrinsic Motivation subscales with each other. This suggests that the differences between Extrinsic and Intrinsic Motivation are not as obvious as has been believed. Also, contrary to self-determination theory, Amotivation had a stronger negative correlation with Identified Regulation (r = -.31) than with any of the Intrinsic Motivation subscales (rs = -.27, -.19, and -.11).

Relativistic fluid theories - Self organization

International Nuclear Information System (INIS)

Mahajan, S.M.; Hazeltine, R.D.; Yoshida, Z.

2003-01-01

Developments in two distinct but related subjects are reviewed: 1) Formulation and investigation of closed fluid theories which transcend the limitations of standard magnetohydrodynamics (MHD), in particular, theories which are valid in the long mean free path limit and in which pressure anisotropy, heat flow, and arbitrarily strong sheared flows are treated consistently, and 2) Exploitation of the two-fluid theories to derive new plasma configurations in which the flow-field is a co-determinant of the overall dynamics; some of these states belong to the category of self-organized relaxed states. Physical processes which may provide a route to self-organization and complexity are also explored. (author)

Theory of edge diffraction in electromagnetics

CERN Document Server

Ufimtsev, Pyotr

2009-01-01

This book is an essential resource for researchers involved in designing antennas and RCS calculations. It is also useful for students studying high frequency diffraction techniques. It contains basic original ideas of the Physical Theory of Diffraction (PTD), examples of its practical application, and its validation by the mathematical theory of diffraction. The derived analytic expressions are convenient for numerical calculations and clearly illustrate the physical structure of the scattered field.

Structure of the [delta]-opioid receptor bound to naltrindole

Energy Technology Data Exchange (ETDEWEB)

Granier, Sébastien; Manglik, Aashish; Kruse, Andrew C.; Kobilka, Tong Sun; Thian, Foon Sun; Weis, William I.; Kobilka, Brian K. (Stanford-MED)

2012-07-11

The opioid receptor family comprises three members, the {mu}-, {delta}- and {kappa}-opioid receptors, which respond to classical opioid alkaloids such as morphine and heroin as well as to endogenous peptide ligands like endorphins. They belong to the G-protein-coupled receptor (GPCR) superfamily, and are excellent therapeutic targets for pain control. The {delta}-opioid receptor ({delta}-OR) has a role in analgesia, as well as in other neurological functions that remain poorly understood. The structures of the {mu}-OR and {kappa}-OR have recently been solved. Here we report the crystal structure of the mouse {delta}-OR, bound to the subtype-selective antagonist naltrindole. Together with the structures of the {mu}-OR and {kappa}-OR, the {delta}-OR structure provides insights into conserved elements of opioid ligand recognition while also revealing structural features associated with ligand-subtype selectivity. The binding pocket of opioid receptors can be divided into two distinct regions. Whereas the lower part of this pocket is highly conserved among opioid receptors, the upper part contains divergent residues that confer subtype selectivity. This provides a structural explanation and validation for the 'message-address' model of opioid receptor pharmacology, in which distinct 'message' (efficacy) and 'address' (selectivity) determinants are contained within a single ligand. Comparison of the address region of the {delta}-OR with other GPCRs reveals that this structural organization may be a more general phenomenon, extending to other GPCR families as well.

Applications of generalizability theory and their relations to classical test theory and structural equation modeling.

Science.gov (United States)

Vispoel, Walter P; Morris, Carrie A; Kilinc, Murat

2018-03-01

Although widely recognized as a comprehensive framework for representing score reliability, generalizability theory (G-theory), despite its potential benefits, has been used sparingly in reporting of results for measures of individual differences. In this article, we highlight many valuable ways that G-theory can be used to quantify, evaluate, and improve psychometric properties of scores. Our illustrations encompass assessment of overall reliability, percentages of score variation accounted for by individual sources of measurement error, dependability of cut-scores for decision making, estimation of reliability and dependability for changes made to measurement procedures, disattenuation of validity coefficients for measurement error, and linkages of G-theory with classical test theory and structural equation modeling. We also identify computer packages for performing G-theory analyses, most of which can be obtained free of charge, and describe how they compare with regard to data input requirements, ease of use, complexity of designs supported, and output produced. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Testing components of Rothbard’s theory with the current information system

Directory of Open Access Journals (Sweden)

Aurelian Virgil BĂLUŢĂ

2016-03-01

Full Text Available The concept of aggression against property rights of individuals generates a series of developments that allow solutions and options to problems and dilemmas of today's economy: the dynamics of the tax system, focusing attention on shaping the budget with macro-economic calculations, the protection of competition, and customs policy in the modern era. The confidence in theory in general, especially in economic theory, is based on the logical and methodological validation of scientific reasoning and moral aspects. Transforming the theory into a means of changing the society can only be made when a theory is experimentally validated. The economic theory needs confirmation from specialized disciplines such as statistics and accounting. It is possible and necessary for the advantages of radical liberal thinking to be reflected in every company’s bookkeeping and in public statistics. As an example, the paper presents the way some components of Rothbard's theory are reflect in the accounting and statistics information system.

An automated system for the analysis of G protein-coupled receptor transmembrane binding pockets: alignment, receptor-based pharmacophores, and their application.

Science.gov (United States)

Kratochwil, Nicole A; Malherbe, Pari; Lindemann, Lothar; Ebeling, Martin; Hoener, Marius C; Mühlemann, Andreas; Porter, Richard H P; Stahl, Martin; Gerber, Paul R

2005-01-01

G protein-coupled receptors (GPCRs) share a common architecture consisting of seven transmembrane (TM) domains. Various lines of evidence suggest that this fold provides a generic binding pocket within the TM region for hosting agonists, antagonists, and allosteric modulators. Here, a comprehensive and automated method allowing fast analysis and comparison of these putative binding pockets across the entire GPCR family is presented. The method relies on a robust alignment algorithm based on conservation indices, focusing on pharmacophore-like relationships between amino acids. Analysis of conservation patterns across the GPCR family and alignment to the rhodopsin X-ray structure allows the extraction of the amino acids lining the TM binding pocket in a so-called ligand binding pocket vector (LPV). In a second step, LPVs are translated to simple 3D receptor pharmacophore models, where each amino acid is represented by a single spherical pharmacophore feature and all atomic detail is omitted. Applications of the method include the assessment of selectivity issues, support of mutagenesis studies, and the derivation of rules for focused screening to identify chemical starting points in early drug discovery projects. Because of the coarseness of this 3D receptor pharmacophore model, however, meaningful scoring and ranking procedures of large sets of molecules are not justified. The LPV analysis of the trace amine-associated receptor family and its experimental validation is discussed as an example. The value of the 3D receptor model is demonstrated for a class C GPCR family, the metabotropic glutamate receptors.

Investigating the little rip and other future singularities of the universe, and validity of the second law of thermodynamics in F(R theory

Directory of Open Access Journals (Sweden)

M Aghaei Abchouyeh

2015-01-01

Full Text Available The future singularities are possible in a universe that is described by F(R theory. In previous studies the occurrence of the singularities in F(R theory have been considered by using a special function for the Hubble parameter and calculating the F(R function for each of the singularities. Using the specified Hubble parameter causes some difficulties in the study of the second law of thermodynamics. In this paper by using the scale factor, the behavior of F(R function near each type of the singularities is considered. We can check the validity of the second law of thermodynamics near the singularities. At first we study the Little Rip and then the other types of singularities are considered. The results show that the second law of thermodynamics is satisfied near the singularity type (I with some special conditions and is violated with some other conditions. it is satisfied near the Little Rip, type (II, (III and (IV singularities

Advantage of the Highly Restricted Odorant Receptor Expression Pattern in Chemosensory Neurons of Drosophila.

Science.gov (United States)

Tharadra, Sana Khalid; Medina, Adriana; Ray, Anandasankar

2013-01-01

A fundamental molecular feature of olfactory systems is that individual neurons express only one receptor from a large odorant receptor gene family. While numerous theories have been proposed, the functional significance and evolutionary advantage of generating a sophisticated one-receptor-per neuron expression pattern is not well understood. Using the genetically tractable Drosophila melanogaster as a model, we demonstrate that the breakdown of this highly restricted expression pattern of an odorant receptor in neurons leads to a deficit in the ability to exploit new food sources. We show that animals with ectopic co-expression of odorant receptors also have a competitive disadvantage in a complex environment with limiting food sources. At the level of the olfactory system, we find changes in both the behavioral and electrophysiological responses to odorants that are detected by endogenous receptors when an olfactory receptor is broadly misexpressed in chemosensory neurons. Taken together these results indicate that restrictive expression patterns and segregation of odorant receptors to individual neuron classes are important for sensitive odor-detection and appropriate olfactory behaviors.

A multidimensional assessment of the validity and utility of alcohol use disorder severity as determined by item response theory models.

Science.gov (United States)

Dawson, Deborah A; Saha, Tulshi D; Grant, Bridget F

2010-02-01

The relative severity of the 11 DSM-IV alcohol use disorder (AUD) criteria are represented by their severity threshold scores, an item response theory (IRT) model parameter inversely proportional to their prevalence. These scores can be used to create a continuous severity measure comprising the total number of criteria endorsed, each weighted by its relative severity. This paper assesses the validity of the severity ranking of the 11 criteria and the overall severity score with respect to known AUD correlates, including alcohol consumption, psychological functioning, family history, antisociality, and early initiation of drinking, in a representative population sample of U.S. past-year drinkers (n=26,946). The unadjusted mean values for all validating measures increased steadily with the severity threshold score, except that legal problems, the criterion with the highest score, was associated with lower values than expected. After adjusting for the total number of criteria endorsed, this direct relationship was no longer evident. The overall severity score was no more highly correlated with the validating measures than a simple count of criteria endorsed, nor did the two measures yield different risk curves. This reflects both within-criterion variation in severity and the fact that the number of criteria endorsed and their severity are so highly correlated that severity is essentially redundant. Attempts to formulate a scalar measure of AUD will do as well by relying on simple counts of criteria or symptom items as by using scales weighted by IRT measures of severity. Published by Elsevier Ireland Ltd.

Assessing the Implicit Theory of Willpower for Strenuous Mental Activities Scale: Multigroup, across-gender, and cross-cultural measurement invariance and convergent and divergent validity.

Science.gov (United States)

Napolitano, Christopher M; Job, Veronika

2018-05-21

Why do some people struggle with self-control (colloquially called willpower) whereas others are able to sustain it during challenging circumstances? Recent research showed that a person's implicit theories of willpower-whether they think self-control capacity is a limited or nonlimited resource-predict sustained self-control on laboratory tasks and on goal-related outcomes in everyday life. The present research tests the Implicit Theory of Willpower for Strenuous Mental Activities Scale (or ITW-M) Scale for measurement invariance across samples and gender within each culture, and two cultural contexts (the U.S. and Switzerland/Germany). Across a series of multigroup confirmatory factor analyses, we found support for the measurement invariance of the ITW-M scale across samples within and across two cultures, as well as across men and women. Further, the analyses showed expected patterns of convergent (with life-satisfaction and trait-self-control) and discriminant validity (with implicit theory of intelligence). These results provide guidelines for future research and clinical practice using the ITW-M scale for the investigation of latent group differences, for example, between gender or cultures. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Cavitation Nuclei: Experiments and Theory

DEFF Research Database (Denmark)

Mørch, Knud Aage

2009-01-01

The Swedish astrophysicist and Nobel Prize winner Hannes Alfven said: Theories come and go - the experiment is here forever. Often a theory, which we set up to describe an observed physical phenomenon, suffers from the lack of knowledge of decisive parameters, and therefore at best the theory...... becomes insufficient. Contrary, the experiment always reveals nature itself, though at prevailing experimental conditions. With essential parameters being out of control and even maybe unidentified, apparently similar experiments may deviate way beyond our expectations. However, these discrepancies offer...... us a chance to reflect on the character of the unknown parameters. In this way non-concordant experimental results may hold the key to the development of better theories - and to new experiments for the testing of their validity. Cavitation and cavitation nuclei are phenomena of that character....

Analysis of General Power Counting Rules in Effective Field Theory

CERN Document Server

Gavela, B M; Manohar, A V; Merlo, L

2016-01-01

We derive the general counting rules for a quantum effective field theory (EFT) in $\\mathsf{d}$ dimensions. The rules are valid for strongly and weakly coupled theories, and 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. The size of cross sections is controlled by the $\\Lambda$ power counting of EFT, not by chiral counting, even for chiral perturbation theory ($\\chi$PT). The relation between $\\Lambda$ and $f$ is generalized to $\\mathsf{d}$ dimensions. We show that the naive dimensional analysis $4\\pi$ counting is related to $\\hbar$ counting. The EFT counting rules are applied to $\\chi$PT, to Standard Model EFT and to the non-trivial case of Higgs EFT, which combines the $\\Lambda$ and chiral counting rules within a single theory.

A nomogram for predicting pathological complete response in patients with human epidermal growth factor receptor 2 negative breast cancer

International Nuclear Information System (INIS)

Jin, Xi; Jiang, Yi-Zhou; Chen, Sheng; Yu, Ke-Da; Ma, Ding; Sun, Wei; Shao, Zhi-Min; Di, Gen-Hong

2016-01-01

The response to neoadjuvant chemotherapy has been proven to predict long-term clinical benefits for patients. Our research is to construct a nomogram to predict pathological complete response of human epidermal growth factor receptor 2 negative breast cancer patients. We enrolled 815 patients who received neoadjuvant chemotherapy from 2003 to 2015 and divided them into a training set and a validation set. Univariate logistic regression was performed to screen for predictors and construct the nomogram; multivariate logistic regression was performed to identify independent predictors. After performing the univariate logistic regression analysis in the training set, tumor size, hormone receptor status, regimens of neoadjuvant chemotherapy and cycles of neoadjuvant chemotherapy were the final predictors for the construction of the nomogram. The multivariate logistic regression analysis demonstrated that T4 status, hormone receptor status and receiving regimen of paclitaxel and carboplatin were independent predictors of pathological complete response. The area under the receiver operating characteristic curve of the training set and the validation set was 0.779 and 0.701, respectively. We constructed and validated a nomogram to predict pathological complete response in human epidermal growth factor receptor 2 negative breast cancer patients. We also identified tumor size, hormone receptor status and paclitaxel and carboplatin regimen as independent predictors of pathological complete response. The online version of this article (doi:10.1186/s12885-016-2652-z) contains supplementary material, which is available to authorized users

Cross-cultural validity of the theory of planned behavior for predicting healthy food choice in secondary school students of Inner Mongolia.

Science.gov (United States)

Shimazaki, Takashi; Bao, Hugejiletu; Deli, Geer; Uechi, Hiroaki; Lee, Ying-Hua; Miura, Kayo; Takenaka, Koji

2017-11-01

Unhealthy eating behavior is a serious health concern among secondary school students in Inner Mongolia. To predict their healthy food choices and devise methods of correcting unhealthy choices, we sought to confirm the cross-cultural validity of the theory of planned behavior among Inner Mongolian students. A cross-sectional study, conducted between November and December 2014. Overall, 3047 students were enrolled. We devised a questionnaire based on the theory of planned behavior to measure its components (intentions, attitudes, subjective norms, and perceived behavioral control) in relation to healthy food choices; we also assessed their current engagement in healthy food choices. A principal component analysis revealed high contribution rates for the components (69.32%-88.77%). A confirmatory factor analysis indicated that the components of the questionnaire had adequate model fit (goodness of fit index=0.997, adjusted goodness of fit index=0.984, comparative fit index=0.998, and root mean square error of approximation=0.049). Notably, data from participants within the suburbs did not support the theory of planned behavior construction. Several paths did not predict the hypothesis variables. However, attitudes toward healthy food choices strongly predicted behavioral intention (path coefficients 0.49-0.77, ptheory of planned behavior can apply to secondary school students in urban areas. Furthermore, attitudes towards healthy food choices were the best predictor of behavioral intentions to engage in such choices in Inner Mongolian students. Copyright © 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Rigorous results in quantum theory of stimulated Raman scattering

International Nuclear Information System (INIS)

Rupasov, V.I.

1993-01-01

The modern theory of stimulated Raman scattering (SRS) of light in resonant media is based on the investigations of appropriate integrable models of the classical field theory by means of the inverse problem method. But, strictly speaking, Raman scattering is a pure spontaneous process and, hence, it is necessary to take into account a quantum nature of the phenomenon. Moreover, there are some questions and problems, for example, the problem of scattered photons statistics, which can be studied only within the framework of the quantum field theory. We have developed an exact quantum theory of SRS for the case of point-like geometry of resonant media (two-level atoms or harmonic oscillators) of the radius r much-lt λ 0 , where λ 0 is the typical wavelength of the light, but all our results are also valid for the case of short extended medium of the length L much-lt l p (l p is the typical size of pulses) when the spatially homogeneous approximation is valid

Can large Nc equivalence between supersymmetric Yang-Mills theory and its orbifold projections be valid?

International Nuclear Information System (INIS)

Kovtun, Pavel; Uensal, Mithat; Yaffe, Laurence G.

2005-01-01

In previous work, we found that necessary and sufficient conditions for large N c equivalence between parent and daughter theories, for a wide class of orbifold projections of U(N c ) gauge theories, are just the natural requirements that the discrete symmetry used to define the projection not be spontaneously broken in the parent theory, and the discrete symmetry permuting equivalent gauge group factors not be spontaneously broken in the daughter theory. In this paper, we discuss the application of this result to Z k projections of N=1 supersymmetric Yang-Mills theory in four dimensions, as well as various multiflavor generalizations. Z k projections with k>2 yielding chiral gauge theories violate the symmetry realization conditions needed for large N c equivalence, due to the spontaneous symmetry breaking of discrete chiral symmetry in the parent super-Yang-Mills theory. But for Z 2 projections, we show that previous assertions of large N c inequivalence, in infinite volume, between the parent and daughter theories were based on incorrect mappings of vacuum energies, theta angles, or connected correlators between the two theories. With the correct identifications, there is no sign of any inconsistency. A subtle but essential feature of the connection between parent and daughter theories involves multivaluedness in the mapping of theta parameters from parent to daughter

Discovery and validation of information theory-based transcription factor and cofactor binding site motifs.

Science.gov (United States)

Lu, Ruipeng; Mucaki, Eliseos J; Rogan, Peter K

2017-03-17

Data from ChIP-seq experiments can derive the genome-wide binding specificities of transcription factors (TFs) and other regulatory proteins. We analyzed 765 ENCODE ChIP-seq peak datasets of 207 human TFs with a novel motif discovery pipeline based on recursive, thresholded entropy minimization. This approach, while obviating the need to compensate for skewed nucleotide composition, distinguishes true binding motifs from noise, quantifies the strengths of individual binding sites based on computed affinity and detects adjacent cofactor binding sites that coordinate with the targets of primary, immunoprecipitated TFs. We obtained contiguous and bipartite information theory-based position weight matrices (iPWMs) for 93 sequence-specific TFs, discovered 23 cofactor motifs for 127 TFs and revealed six high-confidence novel motifs. The reliability and accuracy of these iPWMs were determined via four independent validation methods, including the detection of experimentally proven binding sites, explanation of effects of characterized SNPs, comparison with previously published motifs and statistical analyses. We also predict previously unreported TF coregulatory interactions (e.g. TF complexes). These iPWMs constitute a powerful tool for predicting the effects of sequence variants in known binding sites, performing mutation analysis on regulatory SNPs and predicting previously unrecognized binding sites and target genes. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

G-protein coupling of cannabinoid receptors

International Nuclear Information System (INIS)

Glass, M.

2001-01-01

Full text: Since the cloning of the cannabinoid CB1 and CB2 receptors in the early 1990's extensive research has focused on understanding their signal transduction pathways. While it has been known for sometime that both receptors can couple to intracellular signalling via pertussis toxin sensitive G-proteins (Gi/Go), the specificity and kinetics of these interactions have only recently been elucidated. We have developed an in situ reconstitution approach to investigating receptor-G-protein interactions. This approach involves chaotropic extraction of receptor containing membranes in order to inactivate or remove endogenous G-proteins. Recombinant or isolated brain G-proteins can then be added back to the receptors, and their activation monitored through the binding of [ 35 S]-GTPγS. This technique has been utilised for an extensive study of cannabinoid receptor mediated activation of G-proteins. In these studies we have established that CB1 couples with high affinity to both Gi and Go type G-proteins. In contrast, CB2 couples strongly to Gi, but has a very low affinity for Go. This finding correlated well with the previous findings that while CB1 and CB2 both couple to the inhibition of adenylate cyclase, CB1 but not CB2 could also inhibit calcium channels. We then examined the ability of a range of cannabinoid agonists to activate the Gi and Go via CB1. Conventional receptor theory suggests that a receptor is either active or inactive with regard to a G-protein and that the active receptor activates all relevant G-proteins equally. However, in this study we found that agonists could produce different degrees of activation, depending on which G-protein was present. Further studies have compared the ability of the two endocannabinoids to drive the activation of Gi or Go. These studies show that agonists can induce multiple forms of activated receptor that differ in their ability to catalyse the activation of Gi or Go. The ability of an agonist to drive a receptor

Experimental evidence of the validity of Bahe–Varela theory to describe the volumetric properties of ionic liquids

International Nuclear Information System (INIS)

Rilo, E.; Domínguez-Pérez, M.; Varela, L.M.; Cabeza, O.

2012-01-01

Highlights: ► We present the theoretical equation given by the Bahe–Varela pseudolattice model. ► The adaptation of that model to predict partial molar volume in mixtures is reviewed. ► We fit the B–V equation to 13 ionic liquids (ILs) + 2 solvent binary systems at four temperatures. ► The ILs used were four tetrafluoroborate and four alkyl sulphate imidazoliums, and the solvents water and ethanol. ► The fit quality is excellent for all systems. - Abstract: Bahe–Varela (B–V) theory, based in the pseudo-lattice model, explains the thermodynamics of electrolyte solutions over the whole composition range. Thus, Bahe in 1972 extended the Debye–Huckel theory, developed for the most diluted electrolytes, to more concentrated solutions taking into account long range inter-ionic Coulombian forces. The introduction of long range interactions in the model generates naturally a pseudo-lattice arrangement of the ions in the concentrated liquid. As Bahe’s description fails at very concentrated solutions, in 1997 Varela and co-workers extended that pseudo-lattice theory by including the short range interactions with solvent molecules and other ions. In recent years, with the discovery of ionic liquids, B–V theory has attracted an increasing interest because these compounds can be seen as very concentrated electrolyte solutions (in fact they can be seen as “solutions” in the limit of no solvent!). Following this line, Turmine and co-workers in 2007 adapt the B–V theory to explain the volumetric properties of ionic liquid solutions up to saturation (i.e. the pure compound). They applied the equation extracted to fit the variation of the partial molar volume of three different aqueous solutions of IL with good results. In the present paper, we extend that analysis for systems formed by eight ILs and two solvents: water and ethanol. We have used density measurements for six aqueous mixtures recently published, two with 1-alkyl-3-methyl imidazolium

A Bayesian Framework for False Belief Reasoning in Children: A Rational Integration of Theory-Theory and Simulation Theory.

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Asakura, Nobuhiko; Inui, Toshio

2016-01-01

Two apparently contrasting theories have been proposed to account for the development of children's theory of mind (ToM): theory-theory and simulation theory. We present a Bayesian framework that rationally integrates both theories for false belief reasoning. This framework exploits two internal models for predicting the belief states of others: one of self and one of others. These internal models are responsible for simulation-based and theory-based reasoning, respectively. The framework further takes into account empirical studies of a developmental ToM scale (e.g., Wellman and Liu, 2004): developmental progressions of various mental state understandings leading up to false belief understanding. By representing the internal models and their interactions as a causal Bayesian network, we formalize the model of children's false belief reasoning as probabilistic computations on the Bayesian network. This model probabilistically weighs and combines the two internal models and predicts children's false belief ability as a multiplicative effect of their early-developed abilities to understand the mental concepts of diverse beliefs and knowledge access. Specifically, the model predicts that children's proportion of correct responses on a false belief task can be closely approximated as the product of their proportions correct on the diverse belief and knowledge access tasks. To validate this prediction, we illustrate that our model provides good fits to a variety of ToM scale data for preschool children. We discuss the implications and extensions of our model for a deeper understanding of developmental progressions of children's ToM abilities.

Theory of tapered laser cooling

International Nuclear Information System (INIS)

Okamoto, Hiromi; Wei, J.

1998-01-01

A theory of tapered laser cooling for fast circulating ion beams in a storage ring is constructed. The authors describe the fundamentals of this new cooling scheme, emphasizing that it might be the most promising way to beam crystallization. The cooling rates are analytically evaluated to study the ideal operating condition. They discuss the physical implication of the tapering factor of cooling laser, and show how to determine its optimum value. Molecular dynamics method is employed to demonstrate the validity of the present theory

Validation of non-formal and informal learning from a European perspective – linking validation arrangements with national qualifications frameworks

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Borut Mikulec

2015-12-01

Full Text Available The paper analyses European policy on the validation of non-formal and informal learning, which is presented as a “salvation narrative” that can improve the functioning of the labour market, provide a way out from unemployment and strengthen the competitiveness of the economy. Taking as our starting point recent findings in adult education theory on the validation of non-formal and informal learning, we aim to prove the thesis that what European validation policy promotes is above all economic purpose and that it establishes a “Credential/Credit-exchange” model of validation of non-formal and informal learning. We proceed to ecxamine the effect of European VNIL policy in selected European countries where validation arrangements are linked to the qualifications framework. We find that the “Credential/ Credit-exchange” validation model was first established in a few individual European countries and then transferred, as a “successful” model, to the level of common European VNIL policy.

What If Quantum Theory Violates All Mathematics?

Science.gov (United States)

Rosinger, Elemér Elad

2017-09-01

It is shown by using a rather elementary argument in Mathematical Logic that if indeed, quantum theory does violate the famous Bell Inequalities, then quantum theory must inevitably also violate all valid mathematical statements, and in particular, such basic algebraic relations like 0 = 0, 1 = 1, 2 = 2, 3 = 3, … and so on … An interest in that result is due to the following three alternatives which it imposes upon both Physics and Mathematics: Quantum Theory is inconsistent. Quantum Theory together with Mathematics are inconsistent. Mathematics is inconsistent. In this regard one should recall that, up until now, it is not known whether Mathematics is indeed consistent.

Validity in Mixed Methods Research in Education: The Application of Habermas' Critical Theory

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Long, Haiying

2017-01-01

Mixed methods approach has developed into the third methodological movement in educational research. Validity in mixed methods research as an important issue, however, has not been examined as extensively as that of quantitative and qualitative research. Additionally, the previous discussions of validity in mixed methods research focus on research…

Validation of UTAUT and UTAUT2 scales for deal sites

DEFF Research Database (Denmark)

Sudzina, Frantisek

2016-01-01

, that is usual for an early stage of investigation of anything. The Unified Theory of Acceptance and Use of Technology explains adoption and continues usage motives. The aim of this paper is to validate scales for the first and the second version of the Unified Theory of Acceptance and Use of Technology for deal...

Sociological theory and social reality

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J Díez Nicolás

2014-12-01

Full Text Available This paper pretends to demonstrate the complementary relations between three relatively recent sociological theories, each one of which explains a different aspect of the same social object: the origin, diffusion and change of social and cultural values, aiming at demonstrating that there is not such a thing as a sociological theory that explains all, but rather diverse theories that offer partial explanations of social reality. To that effect, and on the basis of the necessary relationship between theory and research, three different theories are evaluated separately: Hawley’s and Duncan’s theory of the social ecosystem, Galtung’s centre-periphery theory, and Inglehart’s theory of values’ change in modern-industrial societies, offering theoretical and empirical evidence of their complementary relations, based on Spanish and international data. Social ecosystem and centre-periphery theories show a high level of generalization (through space and time and a high level of abstraction, though both can easily operationalize their main concepts through valid and reliable indicators. The theory of values’ change, however, though showing a high level of generalization, is limited in time to the historical period after World War II, and also shows a high level of abstraction. Centre-periphery theory and values’ change theory use individual and collective units of analysis, but social ecosystem theory only uses collective units, by definition. The three theories lead to the conclusion that ‘security’ values will gain a growing importance in present societies.

Building a Practically Useful Theory of Goal Setting and Task Motivation.

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Locke, Edwin A.; Latham, Gary P.

2002-01-01

Summarizes 35 years of empirical research on goal-setting theory, describing core findings of the theory, mechanisms by which goals operate, moderators of goal effects, the relation of goals and satisfaction, and the role of goals as mediators of incentives. Explains the external validity and practical significance of goal setting theory,…

A DFT and semiempirical model-based study of opioid receptor affinity and selectivity in a group of molecules with a morphine structural core.

Science.gov (United States)

Bruna-Larenas, Tamara; Gómez-Jeria, Juan S

2012-01-01

We report the results of a search for model-based relationships between mu, delta, and kappa opioid receptor binding affinity and molecular structure for a group of molecules having in common a morphine structural core. The wave functions and local reactivity indices were obtained at the ZINDO/1 and B3LYP/6-31G(∗∗) levels of theory for comparison. New developments in the expression for the drug-receptor interaction energy expression allowed several local atomic reactivity indices to be included, such as local electronic chemical potential, local hardness, and local electrophilicity. These indices, together with a new proposal for the ordering of the independent variables, were incorporated in the statistical study. We found and discussed several statistically significant relationships for mu, delta, and kappa opioid receptor binding affinity at both levels of theory. Some of the new local reactivity indices incorporated in the theory appear in several equations for the first time in the history of model-based equations. Interaction pharmacophores were generated for mu, delta, and kappa receptors. We discuss possible differences regulating binding and selectivity in opioid receptor subtypes. This study, contrarily to the statistically backed ones, is able to provide a microscopic insight of the mechanisms involved in the binding process.

A DFT and Semiempirical Model-Based Study of Opioid Receptor Affinity and Selectivity in a Group of Molecules with a Morphine Structural Core

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Tamara Bruna-Larenas

2012-01-01

Full Text Available We report the results of a search for model-based relationships between mu, delta, and kappa opioid receptor binding affinity and molecular structure for a group of molecules having in common a morphine structural core. The wave functions and local reactivity indices were obtained at the ZINDO/1 and B3LYP/6-31 levels of theory for comparison. New developments in the expression for the drug-receptor interaction energy expression allowed several local atomic reactivity indices to be included, such as local electronic chemical potential, local hardness, and local electrophilicity. These indices, together with a new proposal for the ordering of the independent variables, were incorporated in the statistical study. We found and discussed several statistically significant relationships for mu, delta, and kappa opioid receptor binding affinity at both levels of theory. Some of the new local reactivity indices incorporated in the theory appear in several equations for the first time in the history of model-based equations. Interaction pharmacophores were generated for mu, delta, and kappa receptors. We discuss possible differences regulating binding and selectivity in opioid receptor subtypes. This study, contrarily to the statistically backed ones, is able to provide a microscopic insight of the mechanisms involved in the binding process.

Noncommutative gauge theories and Kontsevich's formality theorem

International Nuclear Information System (INIS)

Jurco, B.; Schupp, P.; Wess, J.

2001-01-01

The equivalence of star products that arise from the background field with and without fluctuations and Kontsevich's formality theorem allow an explicitly construction of a map that relates ordinary gauge theory and noncommutative gauge theory (Seiberg-Witten map.) Using noncommutative extra dimensions the construction is extended to noncommutative nonabelian gauge theory for arbitrary gauge groups; as a byproduct we obtain a 'Mini Seiberg-Witten map' that explicitly relates ordinary abelian and nonabelian gauge fields. All constructions are also valid for non-constant B-field, and even more generally for any Poisson tensor

On perturbation theory for distance dependent statistics.

Energy Technology Data Exchange (ETDEWEB)

Mashkevich, S V

1994-12-31

It is known that perturbation theory for anyons has to be modified near Bose statistics in order to get correct finite results. For ``distance dependent statistics`` or anyons with smeared flux tubes, perturbation theory is in principle applicable directly but gives results which hold for too small values of the statistical parameter and, in particular, are not valid as the flux tube radius tends to zero. In this paper we discuss the way to modify perturbation theory for this situation, which allows to obtain the appropriate results. (author). 6 refs.

The validation of Huffaz Intelligence Test (HIT)

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Rahim, Mohd Azrin Mohammad; Ahmad, Tahir; Awang, Siti Rahmah; Safar, Ajmain

2017-08-01

In general, a hafiz who can memorize the Quran has many specialties especially in respect to their academic performances. In this study, the theory of multiple intelligences introduced by Howard Gardner is embedded in a developed psychometric instrument, namely Huffaz Intelligence Test (HIT). This paper presents the validation and the reliability of HIT of some tahfiz students in Malaysia Islamic schools. A pilot study was conducted involving 87 huffaz who were randomly selected to answer the items in HIT. The analysis method used includes Partial Least Square (PLS) on reliability, convergence and discriminant validation. The study has validated nine intelligences. The findings also indicated that the composite reliabilities for the nine types of intelligences are greater than 0.8. Thus, the HIT is a valid and reliable instrument to measure the multiple intelligences among huffaz.

Playing to win over: validating persuasive games

NARCIS (Netherlands)

R.S. Jacobs (Ruud)

2017-01-01

textabstractThis dissertation describes four years of scientific inquiry into persuasive games – digital games designed to persuade – as part of a multidisciplinary research project ‘Persuasive Gaming. From Theory-Based Design to Validation and Back’ funded by the Netherlands Organization for

Validation of quantitative brain dopamine D2 receptor imaging with a conventional single-head SPET camera

International Nuclear Information System (INIS)

Nikkinen, P.; Liewendahl, K.; Savolainen, S.; Launes, J.

1993-01-01

Phantom measurements were performed with a conventional single-head single-photon emission tomography (SPET) camera in order to validate the relevance of the basal ganglia/frontal cortex iodine-123 iodobenzamide (IBZM) uptake ratios measured in patients. Inside a cylindrical phantom (diameter 22 cm), two cylinders with a diameter of 3.3 cm were inserted. The activity concentrations of the cylinders ranged from 6.0 to 22.6 kBq/ml and the cylinder/background activity ratios varied from 1.4 to 3.8. From reconstructed SPET images the cylinder/background activity ratios were calculated using three different regions of interest (ROIs). A linear relationship between the measured activity ratio and the true activity ratio was obtained. In patient studies, basal ganglia/frontal cortex IBZM uptake ratios determined from the reconstructed slices using attentuation correction prior to reconstruction were 1.30 ±0.03 in idiopathic Parkinson's disease (n = 9), 1,33 ±0.09 in infantile and juvenile neuronal ceroid lipofuscinosis (n = 7) and 1.34 ±0.05 in narcolepsy (n = 8). Patients with Huntington's disease had significantly lower ratios (1.09 ±0.04, n = 5). The corrected basal ganglia/frontal cortex ratios, determined using linear regression, were about 80 % higher. The use of dual-window scatter correction increased the measured ratios by about 10 %. Although comprehensive correction methods can further improve the resolution in SPET images, the resolution of the SPET system used by us (1.5 - 2 cm) will determine what is achievable in basal ganglia D2 receptor imaging. (orig.)

Validation of quantitative brain dopamine D2 receptor imaging with a conventional single-head SPET camera

Energy Technology Data Exchange (ETDEWEB)

Nikkinen, P [Helsinki Univ. (Finland). Dept. of Clinical Chemistry; Liewendahl, K [Helsinki Univ. (Finland). Dept. of Clinical Chemistry; Savolainen, S [Helsinki Univ. (Finland). Dept. of Physics; Launes, J [Helsinki Univ. (Finland). Dept. of Neurology

1993-08-01

Phantom measurements were performed with a conventional single-head single-photon emission tomography (SPET) camera in order to validate the relevance of the basal ganglia/frontal cortex iodine-123 iodobenzamide (IBZM) uptake ratios measured in patients. Inside a cylindrical phantom (diameter 22 cm), two cylinders with a diameter of 3.3 cm were inserted. The activity concentrations of the cylinders ranged from 6.0 to 22.6 kBq/ml and the cylinder/background activity ratios varied from 1.4 to 3.8. From reconstructed SPET images the cylinder/background activity ratios were calculated using three different regions of interest (ROIs). A linear relationship between the measured activity ratio and the true activity ratio was obtained. In patient studies, basal ganglia/frontal cortex IBZM uptake ratios determined from the reconstructed slices using attentuation correction prior to reconstruction were 1.30 [+-]0.03 in idiopathic Parkinson's disease (n = 9), 1,33 [+-]0.09 in infantile and juvenile neuronal ceroid lipofuscinosis (n = 7) and 1.34 [+-]0.05 in narcolepsy (n = 8). Patients with Huntington's disease had significantly lower ratios (1.09 [+-]0.04, n = 5). The corrected basal ganglia/frontal cortex ratios, determined using linear regression, were about 80 % higher. The use of dual-window scatter correction increased the measured ratios by about 10 %. Although comprehensive correction methods can further improve the resolution in SPET images, the resolution of the SPET system used by us (1.5 - 2 cm) will determine what is achievable in basal ganglia D2 receptor imaging. (orig.)

Assessing the validity of discourse analysis: transdisciplinary convergence

Science.gov (United States)

Jaipal-Jamani, Kamini

2014-12-01

Research studies using discourse analysis approaches make claims about phenomena or issues based on interpretation of written or spoken text, which includes images and gestures. How are findings/interpretations from discourse analysis validated? This paper proposes transdisciplinary convergence as a way to validate discourse analysis approaches to research. The argument is made that discourse analysis explicitly grounded in semiotics, systemic functional linguistics, and critical theory, offers a credible research methodology. The underlying assumptions, constructs, and techniques of analysis of these three theoretical disciplines can be drawn on to show convergence of data at multiple levels, validating interpretations from text analysis.

Environmental education curriculum evaluation questionnaire: A reliability and validity study

Science.gov (United States)

Minner, Daphne Diane

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

Pharmacokinetic-pharmacodynamic analysis of antipsychotics-induced extrapyramidal symptoms based on receptor occupancy theory incorporating endogenous dopamine release.

Science.gov (United States)

Matsui-Sakata, Akiko; Ohtani, Hisakazu; Sawada, Yasufumi

2005-06-01

We aimed to analyze the risks of extrapyramidal symptoms (EPS) induced by typical and atypical antipsychotic drugs using a common pharmacokinetic-pharmacodynamic (PK-PD) model based on the receptor occupancy. We collected the data for EPS induced by atypical antipsychotics, risperidone, olanzapine and quetiapine, and a typical antipsychotic, haloperidol from literature and analyzed the following five indices of EPS, the ratio of patients obliged to take anticholinergic medication, the occurrence rates of plural extrapyramidal symptoms (more than one of tremor, dystonia, hypokinesia, akathisia, extrapyramidal syndrome, etc.), parkinsonism, akathisia, and extrapyramidal syndrome. We tested two models, i.e., a model incorporating endogenous dopamine release owing to 5-HT2A receptor inhibition and a model not considering the endogenous dopamine release, and used them to examine the relationship between the D2 receptor occupancy of endogenous dopamine and the extent of drug-induced EPS. The model incorporating endogenous dopamine release better described the relationship between the mean D2 receptor occupancy of endogenous dopamine and the extent of EPS than the other model, as assessed by the final sum of squares of residuals (final SS) and Akaike's Information Criteria (AIC). Furthermore, the former model could appropriately predict the risks of EPS induced by two other atypical antipsychotics, clozapine and ziprasidone, which were not incorporated into the model development. The developed model incorporating endogenous dopamine release owing to 5-HT2A receptor inhibition may be useful for the prediction of antipsychotics-induced EPS.

Validity of the linear no-threshold theory of radiation carcinogenesis at low doses

International Nuclear Information System (INIS)

Cohen, B.L.

1999-01-01

A great deal is known about the cancer risk of high radiation doses from studies of Japanese A-bomb survivors, patients exposed for medical therapy, occupational exposures, etc. But the vast majority of important applications deal with much lower doses, usually accumulated at much lower dose rates, referred to as 'low-level radiation' (LLR). Conventionally, the cancer risk from LLR has been estimated by the use of linear no-threshold theory (LNT). For example, it is assumed that the cancer risk from 0 01 Sr (100 mrem) of dose is 0 01 times the risk from 1 Sv (100 rem). In recent years, the former risk estimates have often been reduced by a 'dose and dose rate reduction factor', which is taken to be a factor of 2. But otherwise, the LNT is frequently used for doses as low as one hundred-thousandth of those for which there is direct evidence of cancer induction by radiation. It is the origin of the commonly used expression 'no level of radiation is safe' and the consequent public fear of LLR. The importance of this use of the LNT can not be exaggerated and is used in many applications in the nuclear industry. The LNT paradigm has also been carried over to chemical carcinogens, leading to severe restrictions on use of cleaning fluids, organic chemicals, pesticides, etc. If the LNT were abandoned for radiation, it would probably also be abandoned for chemical carcinogens. In view of these facts, it is important to consider the validity of the LNT. That is the purpose of this paper. (author)

Evidence for Alpha Receptors in the Human Ureter

Science.gov (United States)

Madeb, Ralph; Knopf, Joy; Golijanin, Dragan; Bourne, Patricia; Erturk, Erdal

2007-04-01

An immunohistochemical and western blot expression analysis of human ureters was performed in order to characterize the alpha-1-adrenergic receptor distribution along the length of the human ureteral wall. Mapping the distribution will assist in understanding the potential role alpha -1-adrenergic receptors and their subtype density might have in the pathophysiology of ureteral colic and stone passage. Patients diagnosed with renal cancer or bladder cancer undergoing nephrectomy, nephroureterectomy, or cystectomy had ureteral specimens taken from the proximal, mid, distal and tunneled ureter. Tissues were processed for fresh frozen examination and fixed in formalin. None of the ureteral specimens were involved with cancer. Serial histologic sections and immunohistochemical studies were performed using antibodies specific for alpha-1-adrenergic receptor subtypes (alpha 1a, alpha 1b, alpha 1d). The sections were examined under a light microscope and scored as positive or negative. In order to validate and quantify the alpha receptor subtypes along the human ureter. Western blotting techniques were applied. Human ureter stained positively for alpha -1-adrenergic receptors. Immunostaining appeared red, with intense reaction in the smooth muscle of the ureter and endothelium of the neighboring blood vessels. There was differential expression between all the receptors with the highest staining for alpha-1D subtype. The highest protein expression for all three subtypes was in the renal pelvis and decreased with advancement along the ureter to the distal ureter. At the distal ureter, there was marked increase in expression as one progressed towards the ureteral orifice. The same pattern of protein expression was exhibited for all three alpha -1-adrenergic receptor subtypes. We provide preliminary evidence for the ability to detect and quantify the alpha-1-receptor subtypes along the human ureter which to the best of our knowledge has never been done with

Important theories of the 20th century. Relativity, cosmology, quantum mechanics and chaos theory. 3. corr. ed.

International Nuclear Information System (INIS)

Kinnebrock, Werner

2011-01-01

The past century changed the classical, scientific way of view enormously. The quantum theory broke with the imagination of continuity of all dynamical processes and gave space to completely new, nearly revolutionary approaches of thinking. Einstein's relativity theory put the absoluteness of time and space as well as the general validity of the Euclidean geometry in question. The absolute calculability, as it was formulated by Laplace, was by the influence of chaos theory proven as illusion. Computers made by the Mandelbrot set the presentation of new esthetic and never seen structures. Hilbert's century program of a complete formalization of mathematics failed because of the famous law of Goedel. It is the demand of this book to present all these theories and conclusions easily understandably and entertainingly.

General Theory of Absorption in Porous Materials: Restricted Multilayer Theory.

Science.gov (United States)

Aduenko, Alexander A; Murray, Andy; Mendoza-Cortes, Jose L

2018-04-18

In this article, we present an approach for the generalization of adsorption of light gases in porous materials. This new theory goes beyond Langmuir and Brunauer-Emmett-Teller theories, which are the standard approaches that have a limited application to crystalline porous materials by their unphysical assumptions on the amount of possible adsorption layers. The derivation of a more general equation for any crystalline porous framework is presented, restricted multilayer theory. Our approach allows the determination of gas uptake considering only geometrical constraints of the porous framework and the interaction energy of the guest molecule with the framework. On the basis of this theory, we calculated optimal values for the adsorption enthalpy at different temperatures and pressures. We also present the use of this theory to determine the optimal linker length for a topologically equivalent framework series. We validate this theoretical approach by applying it to metal-organic frameworks (MOFs) and show that it reproduces the experimental results for seven different reported materials. We obtained the universal equation for the optimal linker length, given the topology of a porous framework. This work applied the general equation to MOFs and H 2 to create energy-storage materials; however, this theory can be applied to other crystalline porous materials and light gases, which opens the possibility of designing the next generations of energy-storage materials by first considering only the geometrical constraints of the porous materials.

Validity of Linder Hypothesis in Bric Countries

Directory of Open Access Journals (Sweden)

Rana Atabay

2016-03-01

Full Text Available In this study, the theory of similarity in preferences (Linder hypothesis has been introduced and trade in BRIC countries has been examined whether the trade between these countries was valid for this hypothesis. Using the data for the period 1996 – 2010, the study applies to panel data analysis in order to provide evidence regarding the empirical validity of the Linder hypothesis for BRIC countries’ international trade. Empirical findings show that the trade between BRIC countries is in support of Linder hypothesis.

Is the string theory doomed?

International Nuclear Information System (INIS)

Le Meur, H.; Daninos, F.; Bachas, C.

2007-01-01

Since its beginning, in the sixties, the string theory has succeeded in overcoming a lot of theoretical difficulties but now the complete absence of experimental validation entertains doubts about its ability to represent the real world and questions its hegemony in today's theoretical physics. Other space-time theories like the twistors, or the non-commutative geometry, or the loop quantum gravity, or the causal dynamics triangulation might begin receiving more attention. Despite all that, the string theory can be given credit for 4 achievements. First, the string theory has provided a consistent quantum description of gravity. Secondly, the string theory has built a theoretical frame that has allowed the unification of the 4 basic interactions. Thirdly, the string theory applied to astrophysics issues has demonstrated that the evaporation of a black hole does not necessarily lead to a loss of information which comforts the universality of the conservation of the quantity of information in any system and as a consequence put a fatal blow to the so-called paradox observed in black holes. Fourthly, the string theory has given a new and original meaning on the true nature of space-time. (A.C.)

Contribution to a Theory of Detailed Design

DEFF Research Database (Denmark)

Mortensen, Niels Henrik

1999-01-01

It has been recognised, that literature actually do not propose a theory of detailed design. In this paper a theory contribution is proposed, linking part design to organ design and allowing a type of functional reasoning. The proposed theory satisfies our need for explaining the nature of a part...... structure, for support of synthesis of part structure, i.e. detailed design, and our need for digital modelling of part structures.The aim of this paper is to contribute to a design theory valid for detailed design. The proposal is based upon the theory's ability to explain the nature of machine parts...... and assemblies, to support the synthesis of parts and to allow the modelling, especially digital modelling of a part structure. The contribution is based upon Theory of Technical Systems, Hubka, and the Domain Theory, Andreasen. This paper is based on a paper presented at ICED 99, Mortensen, but focus...

Possible Relevance of Receptor-Receptor Interactions between Viral- and Host-Coded Receptors for Viral-Induced Disease

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Luigi F. Agnati

2007-01-01

Full Text Available It has been demonstrated that some viruses, such as the cytomegalovirus, code for G-protein coupled receptors not only to elude the immune system, but also to redirect cellular signaling in the receptor networks of the host cells. In view of the existence of receptor-receptor interactions, the hypothesis is introduced that these viral-coded receptors not only operate as constitutively active monomers, but also can affect other receptor function by interacting with receptors of the host cell. Furthermore, it is suggested that viruses could also insert not single receptors (monomers, but clusters of receptors (receptor mosaics, altering the cell metabolism in a profound way. The prevention of viral receptor-induced changes in host receptor networks may give rise to novel antiviral drugs that counteract viral-induced disease.

Volume independence in large Nc QCD-like gauge theories

International Nuclear Information System (INIS)

Kovtun, Pavel; Uensal, Mithat; Yaffe, Laurence G.

2007-01-01

Volume independence in large N c gauge theories may be viewed as a generalized orbifold equivalence. The reduction to zero volume (or Eguchi-Kawai reduction) is a special case of this equivalence. So is temperature independence in confining phases. A natural generalization concerns volume independence in 'theory space' of quiver gauge theories. In pure Yang-Mills theory, the failure of volume independence for sufficiently small volumes (at weak coupling) due to spontaneous breaking of center symmetry, together with its validity above a critical size, nicely illustrate the symmetry realization conditions which are both necessary and sufficient for large N c orbifold equivalence. The existence of a minimal size below which volume independence fails also applies to Yang-Mills theory with antisymmetric representation fermions [QCD(AS)]. However, in Yang-Mills theory with adjoint representation fermions [QCD(Adj)], endowed with periodic boundary conditions, volume independence remains valid down to arbitrarily small size. In sufficiently large volumes, QCD(Adj) and QCD(AS) have a large N c ''orientifold'' equivalence, provided charge conjugation symmetry is unbroken in the latter theory. Therefore, via a combined orbifold-orientifold mapping, a well-defined large N c equivalence exists between QCD(AS) in large, or infinite, volume and QCD(Adj) in arbitrarily small volume. Since asymptotically free gauge theories, such as QCD(Adj), are much easier to study (analytically or numerically) in small volume, this equivalence should allow greater understanding of large N c QCD in infinite volume

Manufacturing validation of biologically functional T cells targeted to CD19 antigen for autologous adoptive cell therapy

Science.gov (United States)

Hollyman, Daniel; Stefanski, Jolanta; Przybylowski, Mark; Bartido, Shirley; Borquez-Ojeda, Oriana; Taylor, Clare; Yeh, Raymond; Capacio, Vanessa; Olszewska, Malgorzata; Hosey, James; Sadelain, Michel; Brentjens, Renier J.; Rivière, Isabelle

2009-01-01

Summary Based on promising pre-clinical data demonstrating the eradication of systemic B cell malignancies by CD19-targeted T lymphocytes in vivo in SCID beige mouse models, we are launching Phase 1 clinical trials in patients with chronic lymphocytic leukemia (CLL) and acute lymphoblastic leukemia (ALL). We present here the validation of the bioprocess we developed for the production and expansion of clinical grade autologous T cells derived from patients with CLL. We demonstrate that T cells genetically modified with a replication-defective gammaretroviral vector derived from the Moloney murine leukemia virus encoding a chimeric antigen receptor (CAR) targeted to CD19 (1928z) can be expanded with Dynabeads® CD3/CD28. This bioprocess allows us to generate clinical doses of 1928z+ T cells in approximately 2 to 3 weeks in a large-scale semi-closed culture system using the Wave bioreactor. These 1928z+ T cells remain biologically functional not only in vitro but also in SCID beige mice bearing disseminated tumors. The validation requirements in terms of T cell expansion, T cell transduction with the 1928z CAR, biological activity, quality control testing and release criteria were met for all four validation runs using apheresis products from patients with CLL. Additionally, following expansion of the T cells, the diversity of the skewed Vβ T cell receptor repertoire was significantly restored. This validated process will be used in phase I clinical trials in patients with chemo-refractory CLL and in patients with relapsed ALL. It can also be adapted for other clinical trials involving the expansion and transduction of patient or donor T cells using any chimeric antigen receptor or T cell receptor. PMID:19238016

Dynamical theory of subconstituents based on ternary algebras

International Nuclear Information System (INIS)

Bars, I.; Guenaydin, M.

1980-01-01

We propose a dynamical theory of possible fundamental constituents of matter. Our scheme is based on (super) ternary algebras which are building blocks of Lie (super) algebras. Elementary fields, called ''ternons,'' are associated with the elements of a (super) ternary algebra. Effective gauge bosons, ''quarks,'' and ''leptons'' are constructed as composite fields from ternons. We propose two- and four-dimensional (super) ternon theories whose structures are closely related to CP/sub N/ and Yang-Mills theories and their supersymmetric extensions. We conjecture that at large distances (low energies) the ternon theories dynamically produce effective gauge theories and thus may be capable of explaining the present particle-physics phenomenology. Such a scenario is valid in two dimensions

Effective potential for spontaneously broken gauge theories and gauge hierarchies

International Nuclear Information System (INIS)

Hagiwara, T.; Ovrut, B.

1979-01-01

The Appelquist-Carazzone effective-field-theory method, where one uses effective light-field coupling constants dependent on the heavy-field sector, is explicitly shown to be valid for the discussion of the gauge-hierarchy problem in grand unified gauge models. Using the method of functionals we derive an expression for the one-loop approximation to the scalar-field effective potential for spontaneously broken theories in an arbitrary R/sub xi/ gauge. We argue that this potential generates, through its derivatives, valid zero-momentum, one-particle-irreducible vertices for any value of xi (not just the xi→infinity Landau gauge). The equation that the one-loop vacuum correction must satisfy is presented, and we solve this equation for a number of spontaneously broken theories including gauge theories with gauge groups U(1) and SO(3). We find that a one-loop vacuum shift in a massless, non-Goldstone direction occurs via the Coleman-Weinberg mechanism with an effective coupling constant dependent on the heavy-field sector

On the entanglement entropy for gauge theories

International Nuclear Information System (INIS)

Ghosh, Sudip; Soni, Ronak M; Trivedi, Sandip P.

2015-01-01

We propose a definition for the entanglement entropy of a gauge theory on a spatial lattice. Our definition applies to any subset of links in the lattice, and is valid for both Abelian and Non-Abelian gauge theories. For ℤ_N and U(1) theories, without matter, our definition agrees with a particular case of the definition given by Casini, Huerta and Rosabal. We also argue that in general, both for Abelian and Non-Abelian theories, our definition agrees with the entanglement entropy calculated using a definition of the replica trick. Our definition, however, does not agree with some standard ways to measure entanglement, like the number of Bell pairs which can be produced by entanglement distillation.

Exploring the Reliability and Validity of the Social-Moral Awareness Test

Science.gov (United States)

Livesey, Alexandra; Dodd, Karen; Pote, Helen; Marlow, Elizabeth

2012-01-01

Background: The aim of the study was to explore the validity of the social-moral awareness test (SMAT) a measure designed for assessing socio-moral rule knowledge and reasoning in people with learning disabilities. Comparisons between Theory of Mind and socio-moral reasoning allowed the exploration of construct validity of the tool. Factor…

Radiosynthesis and evaluation of 11C-CIMBI-5 as a 5-HT2A receptor agonist radioligand for PET

DEFF Research Database (Denmark)

Ettrup, Anders; Palner, Mikael; Gillings, Nic

2010-01-01

PET brain imaging of the serotonin 2A (5-hydroxytryptamine 2A, or 5-HT(2A)) receptor has been widely used in clinical studies, and currently, several well-validated radiolabeled antagonist tracers are used for in vivo imaging of the cerebral 5-HT(2A) receptor. Access to 5-HT(2A) receptor agonist...... PET tracers would, however, enable imaging of the active, high-affinity state of receptors, which may provide a more meaningful assessment of membrane-bound receptors. In this study, we radiolabel the high-affinity 5-HT(2A) receptor agonist 2-(4-iodo-2,5-dimethoxyphenyl)-N-(2-[(11)C-OCH(3......)]methoxybenzyl)ethanamine ((11)C-CIMBI-5) and investigate its potential as a PET tracer....

Correcting Fallacies in Validity, Reliability, and Classification

Science.gov (United States)

Sijtsma, Klaas

2009-01-01

This article reviews three topics from test theory that continue to raise discussion and controversy and capture test theorists' and constructors' interest. The first topic concerns the discussion of the methodology of investigating and establishing construct validity; the second topic concerns reliability and its misuse, alternative definitions…

Effects of antidepressant drugs on different receptors in the brain

International Nuclear Information System (INIS)

Hall, H.; Oegren, S.-O.

1981-01-01

Radioligand receptor binding techniques were used to characterize the effects of different structural types of antidepressant drugs on neurotransmitter receptors. The tricyclic antidepressants more or less potently inhibited the binding to rat brain preparations of several different radiolabelled ligands ([ 3 H]WB4101, [ 3 H]QNB, [ 3 H]d-LSD, [ 3 H]mepyramine). The potency of the nontricyclic antidepressants varied greatly. Mianserin, potently displaced [ 3 H]mepyramine, [ 3 H]d-LSD and [ 3 H]WB4101 while it was very weak on [ 3 H]QNB-binding. Nomifensine and the specific 5-HT uptake inhibitors zimelidine and alaproclate had very low affinity for these receptors. All the antidepressants tested were practically devoid of activity on [ 3 H]DHA binding, [ 3 H]spiroperidol binding, [ 3 H]flunitrazepam binding, [ 3 H]muscimol binding and [ 3 H]naloxone binding. The implications of these findings for biogenic amine theories of affective disorders are discussed. (Auth.)

Validation of the Physician Teaching Motivation Questionnaire (PTMQ).

Science.gov (United States)

Dybowski, Christoph; Harendza, Sigrid

2015-10-02

Physicians play a major role as teachers in undergraduate medical education. Studies indicate that different forms and degrees of motivation can influence work performance in general and that teachers' motivation to teach can influence students' academic achievements in particular. Therefore, the aim of this study was to develop and to validate an instrument measuring teaching motivations in hospital-based physicians. We chose self-determination theory as a theoretical framework for item and scale development. It distinguishes between different dimensions of motivation depending on the amount of self-regulation and autonomy involved and its empirical evidence has been demonstrated in other areas of research. To validate the new instrument (PTMQ = Physician Teaching Motivation Questionnaire), we used data from a sample of 247 physicians from internal medicine and surgery at six German medical faculties. Structural equation modelling was conducted to confirm the factorial structure, correlation analyses and linear regressions were performed to examine concurrent and incremental validity. Structural equation modelling confirmed a good global fit for the factorial structure of the final instrument (RMSEA = .050, TLI = .957, SRMR = .055, CFI = .966). Cronbach's alphas indicated good internal consistencies for all scales (α = .75 - .89) except for the identified teaching motivation subscale with an acceptable internal consistency (α = .65). Tests of concurrent validity with global work motivation, perceived teaching competence, perceived teaching involvement and voluntariness of lesson allocation delivered theory-consistent results with slight deviations for some scales. Incremental validity over global work motivation in predicting perceived teaching involvement was also confirmed. Our results indicate that the PTMQ is a reliable, valid and therefore suitable instrument for assessing physicians' teaching motivation.

Cosmological constraints on Brans-Dicke theory.

Science.gov (United States)

Avilez, A; Skordis, C

2014-07-04

We report strong cosmological constraints on the Brans-Dicke (BD) theory of gravity using cosmic microwave background data from Planck. We consider two types of models. First, the initial condition of the scalar field is fixed to give the same effective gravitational strength Geff today as the one measured on Earth, GN. In this case, the BD parameter ω is constrained to ω>692 at the 99% confidence level, an order of magnitude improvement over previous constraints. In the second type, the initial condition for the scalar is a free parameter leading to a somewhat stronger constraint of ω>890, while Geff is constrained to 0.981theory and are valid for any Horndeski theory, the most general second-order scalar-tensor theory, which approximates the BD theory on cosmological scales. In this sense, our constraints place strong limits on possible modifications of gravity that might explain cosmic acceleration.

Infrared problems in field perturbation theory

International Nuclear Information System (INIS)

David, Francois.

1982-12-01

The work presented mainly covers questions related to the presence of ''infrared'' divergences in perturbation expansions of the Green functions of certain massless field theories. It is important to determine the mathematical status of perturbation expansions in field theory in order to define the region in which they are valid. Renormalization and the symmetry of a theory are important factors in infrared problems. The main object of this thesis resides in the mathematical techniques employed: integral representations of the Feynman amplitudes; methods for desingularization, regularization and dimensional renormalization. Nonlinear two dimensional space-time sigma models describing Goldstone's low energy boson dynamics associated with a breaking of continuous symmetry are studied. Random surface models are then investigated followed by infrared divergences in super-renormalizable theories. Finally, nonperturbation effects in massless theories are studied by expanding the two-dimensional nonlinear sigma model in 1/N [fr

Construct validity of the Moral Development Scale for Professionals (MDSP

Directory of Open Access Journals (Sweden)

Söderhamn O

2011-05-01

Full Text Available Olle Söderhamn1,2, John Olav Bjørnestad1, Anne Skisland1, Christina Cliffordson21Faculty of Health and Sport Sciences, University of Agder, Grimstad and Kristiansand, Norway; 2Department of Nursing, Health and Culture, University West, Trollhättan, SwedenAbstract: The aim of this study was to investigate the construct validity of the Moral Development Scale for Professionals (MDSP using structural equation modeling. The instrument is a 12-item self-report instrument, developed in the Scandinavian cultural context and based on Kohlberg’s theory. A hypothesized simplex structure model underlying the MDSP was tested through structural equation modeling. Validity was also tested as the proportion of respondents older than 20 years that reached the highest moral level, which according to the theory should be small. A convenience sample of 339 nursing students with a mean age of 25.3 years participated. Results confirmed the simplex model structure, indicating that MDSP reflects a moral construct empirically organized from low to high. A minority of respondents >20 years of age (13.5% scored more than 80% on the highest moral level. The findings support the construct validity of the MDSP and the stages and levels in Kohlberg’s theory.Keywords: Kohlberg, scale testing, simplex structure model, structural equation modeling

Life history theory and breast cancer risk: methodological and theoretical challenges: Response to "Is estrogen receptor negative breast cancer risk associated with a fast life history strategy?".

Science.gov (United States)

Aktipis, Athena

2016-01-01

In a meta-analysis published by myself and co-authors, we report differences in the life history risk factors for estrogen receptor negative (ER-) and estrogen receptor positive (ER+) breast cancers. Our meta-analysis did not find the association of ER- breast cancer risk with fast life history characteristics that Hidaka and Boddy suggest in their response to our article. There are a number of possible explanations for the differences between their conclusions and the conclusions we drew from our meta-analysis, including limitations of our meta-analysis and methodological challenges in measuring and categorizing estrogen receptor status. These challenges, along with the association of ER+ breast cancer with slow life history characteristics, may make it challenging to find a clear signal of ER- breast cancer with fast life history characteristics, even if that relationship does exist. The contradictory results regarding breast cancer risk and life history characteristics illustrate a more general challenge in evolutionary medicine: often different sub-theories in evolutionary biology make contradictory predictions about disease risk. In this case, life history models predict that breast cancer risk should increase with faster life history characteristics, while the evolutionary mismatch hypothesis predicts that breast cancer risk should increase with delayed reproduction. Whether life history tradeoffs contribute to ER- breast cancer is still an open question, but current models and several lines of evidence suggest that it is a possibility. © The Author(s) 2016. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.

Mathematical aspects of the BCS theory of superconductivity and related theories

International Nuclear Information System (INIS)

Braeunlich, Gerhard Albert

2014-01-01

The present work starts with a introduction to the BCS theory, describing superconductivity and superfluidity. The main part consist of a collection of three publications and a paper included in a conference proceedings. The introduction (Chapter 1) includes a brief historical review of the research in the field of superconductivity and superfluidity. It ends with a short summary of the technical applications of superconductivity. In Chapter 2, a derivation of the BCS functional from quantum statistics is presented. Chapter 3 explains the results of the publications mentioned above. In a first work, the validity of the negligence of the direct and exchange energy in the derivation of the BCS functional is examined. Another work addresses the connection between the BCS theory and the Gross-Pitaevskii equation.

Extension of loop quantum gravity to f(R) theories.

Science.gov (United States)

Zhang, Xiangdong; Ma, Yongge

2011-04-29

The four-dimensional metric f(R) theories of gravity are cast into connection-dynamical formalism with real su(2) connections as configuration variables. Through this formalism, the classical metric f(R) theories are quantized by extending the loop quantization scheme of general relativity. Our results imply that the nonperturbative quantization procedure of loop quantum gravity is valid not only for general relativity but also for a rather general class of four-dimensional metric theories of gravity.

Simple example of definitions of truth, validity, consistency, and completeness in quantum mechanics

International Nuclear Information System (INIS)

Benioff, P.

1999-01-01

Besides their use for efficient computation, quantum computers and quantum robots form a base for studying quantum systems that create valid physical theories using mathematics and physics. If quantum mechanics is universally applicable, then quantum mechanics must describe its own validation by these quantum systems. An essential part of this process is the development of a coherent theory of mathematics and quantum-mechanics together. It is expected that such a theory will include a coherent combination of mathematical logical concepts with quantum mechanics. That this might be possible is shown here by defining truth, validity, consistency, and completeness for a quantum-mechanical version of a simple (classical) expression enumeration machine described by Smullyan. Some of the expressions are chosen as sentences denoting the presence or absence of other expressions in the enumeration. Two of the sentences are self-referential. It is seen that, for an interpretation based on a Feynman path sum over expression paths, truth, consistency, and completeness for the quantum system have different properties than for the classical system. For instance, the truth of a sentence S is defined only on those paths containing S. It is undefined elsewhere. Also S and its negation can both be true provided they appear on separate paths. This satisfies the definition of consistency. The definitions of validity and completeness connect the dynamics of the system to the truth of the sentences. It is proved that validity implies consistency. It is seen that the requirements of validity and maximal completeness strongly restrict the allowable dynamics for the quantum system. Aspects of the existence of a valid, maximally complete dynamics are discussed. An exponentially efficient quantum computer is described that is also valid and complete for the set of sentences considered here. copyright 1999 The American Physical Society

Exploring a Theory Describing the Physics of Information Systems, Characterizing the Phenomena of Complex Information Systems

National Research Council Canada - National Science Library

Harmon, Scott

2001-01-01

This project accomplished all of its objectives: document a theory of information physics, conduct a workshop on planing experiments to test this theory, and design experiments that validate this theory...

General fluid theories, variational principles and self-organization

International Nuclear Information System (INIS)

Mahajan, S.M.

2002-01-01

This paper reports two distinct but related advances: (1) The development and application of fluid theories that transcend conventional magnetohydrodynamics (MHD), in particular, theories that are valid in the long-mean-free-path limit and in which pressure anisotropy, heat flow, and arbitrarily strong sheared flows are treated consistently. (2) The discovery of new pressure-confining plasma configurations that are self-organized relaxed states. (author)

The Online Social Support Scale: Measure development and validation.

Science.gov (United States)

Nick, Elizabeth A; Cole, David A; Cho, Sun-Joo; Smith, Darcy K; Carter, T Grace; Zelkowitz, Rachel L

2018-05-21

A new measure, the Online Social Support Scale, was developed based on previous theory, research, and measurement of in-person social support. It includes four subscales: Esteem/Emotional Support, Social Companionship, Informational Support, and Instrumental Support. In college and community samples, factor analytic and item response theory results suggest that subtypes of in-person social support also pertain in the online world. Evidence of reliability, convergent validity, and discriminant validity provide excellent psychometric support for the measure. Construct validity accrues to the measure vis-à-vis support for three hypotheses: (a) Various broad types of Internet platforms for social interactions are differentially associated with online social support and online victimization; (b) similar to in-person social support, online social support offsets the adverse effect of negative life events on self-esteem and depression-related outcome; and (c) online social support counteracts the effects of online victimization in much the same way that in-person friends in one social niche counterbalance rejection in other social niches. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Nursing Care Interpersonal Relationship Questionnaire: elaboration and validation.

Science.gov (United States)

Borges, José Wicto Pereira; Moreira, Thereza Maria Magalhães; Andrade, Dalton Franscisco de

2018-01-08

to elaborate an instrument for the measurement of the interpersonal relationship in nursing care through the Item Response Theory, and the validation thereof. methodological study, which followed the three poles of psychometry: theoretical, empirical and analytical. The Nursing Care Interpersonal Relationship Questionnaire was developed in light of the Imogene King's Interpersonal Conceptual Model and the psychometric properties were studied through the Item Response Theory in a sample of 950 patients attended in Primary, Secondary and Tertiary Health Care. the final instrument consisted of 31 items, with Cronbach's alpha of 0.90 and McDonald's Omega of 0.92. The parameters of the Item Response Theory demonstrated high discrimination in 28 items, being developed a five-level interpretive scale. At the first level, the communication process begins, gaining a wealth of interaction. Subsequent levels demonstrate qualitatively the points of effectiveness of the interpersonal relationship with the involvement of behaviors related to the concepts of transaction and interaction, followed by the concept of role. the instrument was created and proved to be consistent to measure interpersonal relationship in nursing care, as it presented adequate reliability and validity parameters.

Nursing Care Interpersonal Relationship Questionnaire: elaboration and validation

Directory of Open Access Journals (Sweden)

José Wicto Pereira Borges

2018-01-01

Full Text Available ABSTRACT Objective: to elaborate an instrument for the measurement of the interpersonal relationship in nursing care through the Item Response Theory, and the validation thereof. Method: methodological study, which followed the three poles of psychometry: theoretical, empirical and analytical. The Nursing Care Interpersonal Relationship Questionnaire was developed in light of the Imogene King’s Interpersonal Conceptual Model and the psychometric properties were studied through the Item Response Theory in a sample of 950 patients attended in Primary, Secondary and Tertiary Health Care. Results: the final instrument consisted of 31 items, with Cronbach’s alpha of 0.90 and McDonald’s Omega of 0.92. The parameters of the Item Response Theory demonstrated high discrimination in 28 items, being developed a five-level interpretive scale. At the first level, the communication process begins, gaining a wealth of interaction. Subsequent levels demonstrate qualitatively the points of effectiveness of the interpersonal relationship with the involvement of behaviors related to the concepts of transaction and interaction, followed by the concept of role. Conclusion: the instrument was created and proved to be consistent to measure interpersonal relationship in nursing care, as it presented adequate reliability and validity parameters.

Gaussian-2 theory using reduced Moller--Plesset orders

International Nuclear Information System (INIS)

Curtiss, L.A.; Raghavachari, K.; Pople, J.A.

1993-01-01

Two variations of Gaussian-2 (G2) theory are presented. In the first, referred to as G2 (MP2) theory, the basis-set-extension energy corrections are obtained at the 2nd order Moller--Plesset (MP2) level and in the second, referred to as G2(MP3) theory, they are obtained at the MP3 level. The methods are tested out on the set of 125 systems used for validation of G2 theory [J. Chem Phys. 94, 7221 (1991)]. The average absolute deviation of the G2(MP2) and G2(MP3) theories from experiment are 1.58 and 1.52 kcal/mol, respectively, compared to 1.21 kcal/mol for G2 theory. The new methods provide significant savings in computational time and disk storage

In search of truth: the regulatory necessity of validation

International Nuclear Information System (INIS)

Niederer, U.

1991-01-01

A look at modern ideas of how scientific truth is achieved shows that theories are not really proved but accepted by a consensus of the experts, borne out by often repeated experience showing a theory to work well. In the same sense acceptability of models in waste disposal is mostly based on consensus. To obtain consensus of the relevant experts, including regulators, all models which considerably influence the results of a safety assessment have to be validated. This is particularly important for the models of geospheric migration because scientific experience with the deep underground is scarce. Validation plays a special role in public acceptance where regulators and other groups, which act as intermediaries between the public and the project manager, have to be convinced that all the relevant models are correct

The Histamine H4 Receptor: From Orphan to the Clinic

Directory of Open Access Journals (Sweden)

Robin L. Thurmond

2015-03-01

Full Text Available The histamine H4 receptor (H4R was first noted as a sequence in genomic databases that had features of a G-protein coupled receptor. This putative receptor was found to bind histamine consistent with its homology to other histamine receptors and thus became the fourth member of the histamine receptor family. Due to the previous success of drugs that target the H1 and H2 receptors, an effort was made to understand the function of this receptor and determine if it represented a drug target. Taking advantage of the vast literature on histamine, a search for histamine activity that did not appear to be mediated by the other three histamine receptors was undertaken. From this asthma and pruritus emerged as areas of particular interest. Histamine has long been suspected to play a role in the pathogenesis of asthma, but antihistamines that target the H1 and H2 receptors have not been shown to be effective for this condition. The use of selective ligands in animal models of asthma has now potentially filled this gap by showing a role for the H4R in mediating lung function and inflammation. A similar story exists for chronic pruritus associated with conditions such as atopic dermatitis. Antihistamines that target the H1 receptor are effective in reducing acute pruritus, but are ineffective in pruritus experienced by patients with atopic dermatitis. As for asthma, animal models have now suggested a role for the H4R in mediating pruritic responses, with antagonists to the H4R reducing pruritus in a number of different conditions. The anti-pruritic effect of H4R antagonists has recently been shown in human clinical studies, validating the preclinical findings in the animal models. A selective H4R antagonist inhibited histamine-induced pruritus in health volunteers and reduced pruritus in patients with atopic dermatitis. The history to date of the H4R provides an excellent example of the deorphanization of a novel receptor and the translation of this into

Somatostatin receptors

DEFF Research Database (Denmark)

Møller, Lars Neisig; Stidsen, Carsten Enggaard; Hartmann, Bolette

2003-01-01

functional units, receptors co-operate. The total receptor apparatus of individual cell types is composed of different-ligand receptors (e.g. SRIF and non-SRIF receptors) and co-expressed receptor subtypes (e.g. sst(2) and sst(5) receptors) in characteristic proportions. In other words, levels of individual......-peptides, receptor agonists and antagonists. Relatively long half lives, as compared to those of the endogenous ligands, have been paramount from the outset. Motivated by theoretical puzzles or the shortcomings of present-day diagnostics and therapy, investigators have also aimed to produce subtype...

Motivasyonel Dil (MD Teorisi ve Ölçme Aracının Türkçede Geçerlik ve Güvenilirlik Analizi = The Relaibility and Validity Analyses of Motivational Language Theory and Scale

Directory of Open Access Journals (Sweden)

Türker BAŞ

2011-08-01

Full Text Available When the literature of leadership and communication is examined, it can be identified that until 1990s, there was not enough study on the effects of a leader’s language and its content on motivation and performance of employees. This gap was filled in theoretical dimension by the Motivating Language Theory by Sullivan (1988 and as an extension of this theory, the Motivating Language Scale developed by Mayfield, Mayfield and Kopf (1995 based on the former study closed in practical dimension. In this study, the scale developed by Mayfield, Mayfield and Kopf (1995 has been tested for its validity and reliability. As a result of analyses carried out, it has been determined that the scale has a high rate of validity and reliability. Therefore, it is assessed that this scale can contribute to empirical studies in the future.

Sociological Theory and Social Reality [ENG

Directory of Open Access Journals (Sweden)

JUAN DÍEZ NICOLÁS

2013-01-01

Full Text Available This paper pretends to demonstrate the complementary relations between three relatively recent sociological theories, each one of which explains a different aspect of the same social object: the origin, diffusion and change of social and cultural values, aiming at demonstrating that there is not such a thing as a sociological theory that explains all, but rather diverse theories that offer partial explanations of social reality. To that effect, and on the basis of the necessary relationship between theory and research, three different theories are evaluated separately: Hawley?s and Duncan?s theory of the social ecosystem, Galtung?s centre-periphery theory, and Inglehart?s theory of values? change in modern-industrial societies, offering theoretical and empirical evidence of their complementary relations, based on Spanish and international data. Social ecosystem and centre-periphery theories show a high level of generalization (through space and time and a high level of abstraction, though both can easily operationalize their main concepts through valid and reliable indicators. The theory of values? change, however, though showing a high level of generalization, is limited in time to the historical period after World War II, and also shows a high level of abstraction. Centre-periphery theory and values? change theory use individual and collective units of analysis, but social ecosystem theory only uses collective units, by definition. The three theories lead to the conclusion that ?security? values will gain a growing importance in present societies.

Development and validation of the Multimodal Presence Scale for virtual reality environments

DEFF Research Database (Denmark)

Makransky, Guido; Jensen, Lau Lilleholt; Aaby, Anders

2017-01-01

of a standardized multidimensional measure of presence (the MPS) for a VR learning context based on this theory, and its validation using confirmatory factor analysis and item response theory. The results from Study 1 which included 161 medical students from Denmark indicated that the items used in the MPS measure...

Validation of molecular crystal structures from powder diffraction data with dispersion-corrected density functional theory (DFT-D)

International Nuclear Information System (INIS)

Streek, Jacco van de; Neumann, Marcus A.

2014-01-01

The accuracy of 215 experimental organic crystal structures from powder diffraction data is validated against a dispersion-corrected density functional theory method. In 2010 we energy-minimized 225 high-quality single-crystal (SX) structures with dispersion-corrected density functional theory (DFT-D) to establish a quantitative benchmark. For the current paper, 215 organic crystal structures determined from X-ray powder diffraction (XRPD) data and published in an IUCr journal were energy-minimized with DFT-D and compared to the SX benchmark. The on average slightly less accurate atomic coordinates of XRPD structures do lead to systematically higher root mean square Cartesian displacement (RMSCD) values upon energy minimization than for SX structures, but the RMSCD value is still a good indicator for the detection of structures that deserve a closer look. The upper RMSCD limit for a correct structure must be increased from 0.25 Å for SX structures to 0.35 Å for XRPD structures; the grey area must be extended from 0.30 to 0.40 Å. Based on the energy minimizations, three structures are re-refined to give more precise atomic coordinates. For six structures our calculations provide the missing positions for the H atoms, for five structures they provide corrected positions for some H atoms. Seven crystal structures showed a minor error for a non-H atom. For five structures the energy minimizations suggest a higher space-group symmetry. For the 225 SX structures, the only deviations observed upon energy minimization were three minor H-atom related issues. Preferred orientation is the most important cause of problems. A preferred-orientation correction is the only correction where the experimental data are modified to fit the model. We conclude that molecular crystal structures determined from powder diffraction data that are published in IUCr journals are of high quality, with less than 4% containing an error in a non-H atom

A theory of human error

Science.gov (United States)

Mcruer, D. T.; Clement, W. F.; Allen, R. W.

1981-01-01

Human errors tend to be treated in terms of clinical and anecdotal descriptions, from which remedial measures are difficult to derive. Correction of the sources of human error requires an attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A comprehensive analytical theory of the cause-effect relationships governing propagation of human error is indispensable to a reconstruction of the underlying and contributing causes. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation, maritime, automotive, and process control operations is highlighted. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.

The g-theorem and quantum information theory

Energy Technology Data Exchange (ETDEWEB)

Casini, Horacio; Landea, Ignacio Salazar; Torroba, Gonzalo [Centro Atómico Bariloche and CONICET,S.C. de Bariloche, Río Negro, R8402AGP (Argentina)

2016-10-25

We study boundary renormalization group flows between boundary conformal field theories in 1+1 dimensions using methods of quantum information theory. We define an entropic g-function for theories with impurities in terms of the relative entanglement entropy, and we prove that this g-function decreases along boundary renormalization group flows. This entropic g-theorem is valid at zero temperature, and is independent from the g-theorem based on the thermal partition function. We also discuss the mutual information in boundary RG flows, and how it encodes the correlations between the impurity and bulk degrees of freedom. Our results provide a quantum-information understanding of (boundary) RG flow as increase of distinguishability between the UV fixed point and the theory along the RG flow.

On multiscale moving contact line theory.

Science.gov (United States)

Li, Shaofan; Fan, Houfu

2015-07-08

In this paper, a multiscale moving contact line (MMCL) theory is presented and employed to simulate liquid droplet spreading and capillary motion. The proposed MMCL theory combines a coarse-grained adhesive contact model with a fluid interface membrane theory, so that it can couple molecular scale adhesive interaction and surface tension with hydrodynamics of microscale flow. By doing so, the intermolecular force, the van der Waals or double layer force, separates and levitates the liquid droplet from the supporting solid substrate, which avoids the shear stress singularity caused by the no-slip condition in conventional hydrodynamics theory of moving contact line. Thus, the MMCL allows the difference of the surface energies and surface stresses to drive droplet spreading naturally. To validate the proposed MMCL theory, we have employed it to simulate droplet spreading over various elastic substrates. The numerical simulation results obtained by using MMCL are in good agreement with the molecular dynamics results reported in the literature.

Bootstrapping N=3 superconformal theories

Energy Technology Data Exchange (ETDEWEB)

Lemos, Madalena; Liendo, Pedro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Meneghelli, Carlo [Stony Brook Univ., Stony Brook, NY (United States). Simons Center for Geometry and Physics; Mitev, Vladimir [Mainz Univ. (Germany). PRISMA Cluster of Excellence

2016-12-15

We initiate the bootstrap program for N=3 superconformal field theories (SCFTs) in four dimensions. The problem is considered from two fronts: the protected subsector described by a 2d chiral algebra, and crossing symmetry for half-BPS operators whose superconformal primaries parametrize the Coulomb branch of N=3 theories. With the goal of describing a protected subsector of a family of =3 SCFTs, we propose a new 2d chiral algebra with super Virasoro symmetry that depends on an arbitrary parameter, identified with the central charge of the theory. Turning to the crossing equations, we work out the superconformal block expansion and apply standard numerical bootstrap techniques in order to constrain the CFT data. We obtain bounds valid for any theory but also, thanks to input from the chiral algebra results, we are able to exclude solutions with N=4 supersymmetry, allowing us to zoom in on a specific N=3 SCFT.

Bootstrapping N=3 superconformal theories

Energy Technology Data Exchange (ETDEWEB)

Lemos, Madalena; Liendo, Pedro [DESY Hamburg, Theory Group,Notkestrasse 85, D-22607 Hamburg (Germany); Meneghelli, Carlo [Simons Center for Geometry and Physics,Stony Brook University, Stony Brook, NY 11794-3636 (United States); Mitev, Vladimir [PRISMA Cluster of Excellence, Institut für Physik,JGU Mainz, Staudingerweg 7, 55128 Mainz (Germany)

2017-04-06

We initiate the bootstrap program for N=3 superconformal field theories (SCFTs) in four dimensions. The problem is considered from two fronts: the protected subsector described by a 2d chiral algebra, and crossing symmetry for half-BPS operators whose superconformal primaries parametrize the Coulomb branch of N=3 theories. With the goal of describing a protected subsector of a family of N=3 SCFTs, we propose a new 2d chiral algebra with super Virasoro symmetry that depends on an arbitrary parameter, identified with the central charge of the theory. Turning to the crossing equations, we work out the superconformal block expansion and apply standard numerical bootstrap techniques in order to constrain the CFT data. We obtain bounds valid for any theory but also, thanks to input from the chiral algebra results, we are able to exclude solutions with N=4 supersymmetry, allowing us to zoom in on a specific N=3 SCFT.

Kinetic theory for dilute cohesive granular gases with a square well potential.

Science.gov (United States)

Takada, Satoshi; Saitoh, Kuniyasu; Hayakawa, Hisao

2016-07-01

We develop the kinetic theory of dilute cohesive granular gases in which the attractive part is described by a square well potential. We derive the hydrodynamic equations from the kinetic theory with the microscopic expressions for the dissipation rate and the transport coefficients. We check the validity of our theory by performing the direct simulation Monte Carlo.

On the validity of Brownian assumptions in the spin van der Waals model

International Nuclear Information System (INIS)

Oh, Suhk Kun

1985-01-01

A simple Brownian motion theory of the spin van der Waals model, which can be stationary, Markoffian or Gaussian, is studied. By comparing the Brownian motion theory with an exact theory called the generalized Langevin equation theory, the validity of the Brownian assumptions is tested. Thereby, it is shown explicitly how the Markoffian and Gaussian properties are modified in the spin van der Waals model under the influence of quantum fluctuations and long range ordering. (Author)

Validation of the production process of core-equipment HYNIC-Bombesin-Sn

International Nuclear Information System (INIS)

Rubio C, N. I.

2008-01-01

The validation process is establishing documented evidence that provides a high degree of assurance that a specific process consistently will produce a product that will meet specifications and quality attributes preset and, therefore, ensures the efficiency and effectiveness of a product. The radiopharmaceutical 99m Tc-HYNlC-Bombesin is part of the gastrin-releasing peptide (GRP) analogues of bombesin that are radiolabelled with technetium 99 metastable for molecular images obtention. Is obtained from freeze-dry formulations kits (core- equipment)) and has reported a very high stability in human serum, specific binding to receptors and rapid internalization. Biodistribution data in mice showed rapid blood clearance with predominant renal excretion and specific binding to tissues with positive response to GRP receptors. According to biokinetics studies performed on patients with breast cancer, breast show a marked asymmetry with increased uptake in neoplastic breast in healthy women and the uptake of radiopharmaceuticals is symmetrical in both breasts. No reported adverse reactions. In this paper, the prospective validation core-equipment HYNlC-Bombesin-Sn, which was shown consistently that the product meets the specifications and quality, attributes to preset from the obtained from the diagnostic radiopharmaceutical third generation: 99m Tc-HYNlC-Bombesin. The process was successfully validated and thereby ensuring the efficiency and effectiveness of this agent as a preliminary diagnostic for approval to be marketed. (Author)

Salinas : theory manual.

Energy Technology Data Exchange (ETDEWEB)

Walsh, Timothy Francis; Reese, Garth M.; Bhardwaj, Manoj Kumar

2011-11-01

Salinas provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of structural systems. This manual describes the theory behind many of the constructs in Salinas. For a more detailed description of how to use Salinas, we refer the reader to Salinas, User's Notes. Many of the constructs in Salinas are pulled directly from published material. Where possible, these materials are referenced herein. However, certain functions in Salinas are specific to our implementation. We try to be far more complete in those areas. The theory manual was developed from several sources including general notes, a programmer notes manual, the user's notes and of course the material in the open literature.

The relationship of cerb B 2 expression with estrogen receptor and progesterone receptor and prognostic parameters in endometrial carcinomas

Directory of Open Access Journals (Sweden)

Kandemir Nilufer

2010-02-01

Full Text Available Abstract Background Endometrial carcinoma (EC is the most common malignancy of the female genital tract. Gene alterations and overexpression of various oncogenes are important in tumor development. The human HER 2 neu (c-erbB-2 gene product is a transmembrane receptor with an intracellular tyrosine kinase that plays an important role in coordinating the endometrial growth factor receptor signaling network. The aim of this study was to investigate the expression of c-erbB-2 in endometrial cancer, to study its correlation to established prognostic parameters and estrogen receptor (ER and progesterone receptor (PR status. Methods Immunohistochemical (IHC analyses of ER, PR and c-erbB-2 were performed in 72 EC cases. Results We detected a positive staining with c erbB 2 in 18.1% of the cases and determined a statistically significant relation between c-erbB-2 and PR. We could not find a statistically significant relation between c-erbB-2 staining and ER. There was not a statistically significant difference between c-erbB-2 and histological grade. The highest level of c-erbB-2 was found in grade 2 cases. There was not any statistically significant relation between c-erbB-2 and menstrual status, myometrial invasion, lymph node status, stage and survival. Conclusions Although our study provides additional evidence of the potential prognostic role of c-erbB-2, further prospective and controlled studies are required to validate their clinical usefulness.

Selective suppression of endothelial cytokine production by progesterone receptor

OpenAIRE

Goddard, Lauren M.; Ton, Amy N.; Org, Tõnis; Mikkola, Hanna K.A.; Iruela-Arispe, M. Luisa

2013-01-01

Steroid hormones are well-recognized suppressors of the inflammatory response, however, their cell- and tissue-specific effects in the regulation of inflammation are far less understood, particularly for the sex-related steroids. To determine the contribution of progesterone in the endothelium, we have characterized and validated an in vitro culture system in which human umbilical vein endothelial cells constitutively express human progesterone receptor (PR). Using next generation RNA-sequenc...

Reconceptualising the external validity of discrete choice experiments.

Science.gov (United States)

Lancsar, Emily; Swait, Joffre

2014-10-01

External validity is a crucial but under-researched topic when considering using discrete choice experiment (DCE) results to inform decision making in clinical, commercial or policy contexts. We present the theory and tests traditionally used to explore external validity that focus on a comparison of final outcomes and review how this traditional definition has been empirically tested in health economics and other sectors (such as transport, environment and marketing) in which DCE methods are applied. While an important component, we argue that the investigation of external validity should be much broader than a comparison of final outcomes. In doing so, we introduce a new and more comprehensive conceptualisation of external validity, closely linked to process validity, that moves us from the simple characterisation of a model as being or not being externally valid on the basis of predictive performance, to the concept that external validity should be an objective pursued from the initial conceptualisation and design of any DCE. We discuss how such a broader definition of external validity can be fruitfully used and suggest innovative ways in which it can be explored in practice.

Characterizing ligand-gated ion channel receptors with genetically encoded Ca2++ sensors.

Directory of Open Access Journals (Sweden)

John G Yamauchi

2011-01-01

Full Text Available We present a cell based system and experimental approach to characterize agonist and antagonist selectivity for ligand-gated ion channels (LGIC by developing sensor cells stably expressing a Ca(2+ permeable LGIC and a genetically encoded Förster (or fluorescence resonance energy transfer (FRET-based calcium sensor. In particular, we describe separate lines with human α7 and human α4β2 nicotinic acetylcholine receptors, mouse 5-HT(3A serotonin receptors and a chimera of human α7/mouse 5-HT(3A receptors. Complete concentration-response curves for agonists and Schild plots of antagonists were generated from these sensors and the results validate known pharmacology of the receptors tested. Concentration-response relations can be generated from either the initial rate or maximal amplitudes of FRET-signal. Although assaying at a medium throughput level, this pharmacological fluorescence detection technique employs a clonal line for stability and has versatility for screening laboratory generated congeners as agonists or antagonists on multiple subtypes of ligand-gated ion channels. The clonal sensor lines are also compatible with in vivo usage to measure indirectly receptor activation by endogenous neurotransmitters.

Gauge and integrable theories in loop spaces

International Nuclear Information System (INIS)

Ferreira, L.A.; Luchini, G.

2012-01-01

We propose an integral formulation of the equations of motion of a large class of field theories which leads in a quite natural and direct way to the construction of conservation laws. The approach is based on generalized non-abelian Stokes theorems for p-form connections, and its appropriate mathematical language is that of loop spaces. The equations of motion are written as the equality of a hyper-volume ordered integral to a hyper-surface ordered integral on the border of that hyper-volume. The approach applies to integrable field theories in (1+1) dimensions, Chern-Simons theories in (2+1) dimensions, and non-abelian gauge theories in (2+1) and (3+1) dimensions. The results presented in this paper are relevant for the understanding of global properties of those theories. As a special byproduct we solve a long standing problem in (3+1)-dimensional Yang-Mills theory, namely the construction of conserved charges, valid for any solution, which are invariant under arbitrary gauge transformations.

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

Science.gov (United States)

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

2002-10-01

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

Structural determinants for selective recognition of peptide ligands for endothelin receptor subtypes ETA and ETB.

Science.gov (United States)

Lättig, Jens; Oksche, Alexander; Beyermann, Michael; Rosenthal, Walter; Krause, Gerd

2009-07-01

The molecular basis for recognition of peptide ligands endothelin-1, -2 and -3 in endothelin receptors is poorly understood. Especially the origin of ligand selectivity for ET(A) or ET(B) is not clearly resolved. We derived sequence-structure-function relationships of peptides and receptors from mutational data and homology modeling. Our major findings are the dissection of peptide ligands into four epitopes and the delineation of four complementary structural portions on receptor side explaining ligand recognition in both endothelin receptor subtypes. In addition, structural determinants for ligand selectivity could be described. As a result, we could improve the selectivity of BQ3020 about 10-fold by a single amino acid substitution, validating our hypothesis for ligand selectivity caused by different entrances to the receptors' transmembrane binding sites. A narrow tunnel shape in ET(A) is restrictive for a selected group of peptide ligands' N-termini, whereas a broad funnel-shaped entrance in ET(B) accepts a variety of different shapes and properties of ligands.

The emerging role of promiscuous 7TM receptors as chemosensors for food intake.

Science.gov (United States)

Wellendorph, Petrine; Johansen, Lars Dan; Bräuner-Osborne, Hans

2010-01-01

In recent years, several highly promiscuous seven transmembrane (7TM) receptors have been cloned and characterized of which many are activated broadly by amino acids, proteolytic degradation products, carbohydrates, or free fatty acids (FFAs) and are expressed in taste tissue, the gastrointestinal (GI) tract, endocrine glands, adipose tissue, and/or kidney. This has led to the hypothesis that these receptors may act as sensors of food intake modulating, for example, release of incretin hormones from the gut, insulin/glucagon from the pancreas, and leptin from adipose tissue. In the present review, we describe the molecular mechanisms of nutrient-sensing of the calcium-sensing receptor (CaR), the G protein-coupled receptor family C, group 6, subtype A (GPRC6A), and the taste1 receptor T1R1/T1R3-sensing L-α-amino acids; the carbohydrate-sensing T1R2/T1R3 receptor; the proteolytic degradation product sensor GPR93 (also termed GPR92); and the FFA sensing receptors FFA1, FFA2, FFA3, GPR84, and GPR120. Due to their omnipresent nature, the natural ligands have had limited usability in pharmacological/physiological studies which has hampered the elucidation of the physiological function and therapeutic prospect of their receptors. However, an increasing number of subtype-selective ligands and/or receptor knockout mice are being developed which at least for some of the receptors have validated them as promising drug targets in, for example, type II diabetes. Copyright © 2010 Elsevier Inc. All rights reserved.

Control of underactuated driftless systems using higher-order averaging theory

OpenAIRE

Vela, Patricio A.; Burdick, Joel W.

2003-01-01

This paper applies a recently developed "generalized averaging theory" to construct stabilizing feedback control laws for underactuated driftless systems. These controls exponentialy stabilize in the average; the actual system may orbit around the average. Conditions for which the orbit collapses to the averaged trajectory are given. An example validates the theory, demonstrating its utility.

Calibration, validation, and sensitivity analysis: What's what

International Nuclear Information System (INIS)

Trucano, T.G.; Swiler, L.P.; Igusa, T.; Oberkampf, W.L.; Pilch, M.

2006-01-01

One very simple interpretation of calibration is to adjust a set of parameters associated with a computational science and engineering code so that the model agreement is maximized with respect to a set of experimental data. One very simple interpretation of validation is to quantify our belief in the predictive capability of a computational code through comparison with a set of experimental data. Uncertainty in both the data and the code are important and must be mathematically understood to correctly perform both calibration and validation. Sensitivity analysis, being an important methodology in uncertainty analysis, is thus important to both calibration and validation. In this paper, we intend to clarify the language just used and express some opinions on the associated issues. We will endeavor to identify some technical challenges that must be resolved for successful validation of a predictive modeling capability. One of these challenges is a formal description of a 'model discrepancy' term. Another challenge revolves around the general adaptation of abstract learning theory as a formalism that potentially encompasses both calibration and validation in the face of model uncertainty

Preparation and validation of radio iodinated recombinant human IL-10 for the measurement of natural human antibodies against IL-10

DEFF Research Database (Denmark)

de Lemos Rieper, Carina; Galle, Pia; Svenson, Morten

2009-01-01

activity of 75 cpm/pg. Validation of the tracer confirmed preserved antibody epitopes and receptor binding ability. A robust Radio Immuno Assay (RIA) was developed and validated to detect natural human anti-IL-10 antibodies based on the formation of (125)I-labeled IL-10-IgG complexes in solution...

Dopamine and extinction: a convergence of theory with fear and reward circuitry.

Science.gov (United States)

Abraham, Antony D; Neve, Kim A; Lattal, K Matthew

2014-02-01

Research on dopamine lies at the intersection of sophisticated theoretical and neurobiological approaches to learning and memory. Dopamine has been shown to be critical for many processes that drive learning and memory, including motivation, prediction error, incentive salience, memory consolidation, and response output. Theories of dopamine's function in these processes have, for the most part, been developed from behavioral approaches that examine learning mechanisms in reward-related tasks. A parallel and growing literature indicates that dopamine is involved in fear conditioning and extinction. These studies are consistent with long-standing ideas about appetitive-aversive interactions in learning theory and they speak to the general nature of cellular and molecular processes that underlie behavior. We review the behavioral and neurobiological literature showing a role for dopamine in fear conditioning and extinction. At a cellular level, we review dopamine signaling and receptor pharmacology, cellular and molecular events that follow dopamine receptor activation, and brain systems in which dopamine functions. At a behavioral level, we describe theories of learning and dopamine function that could describe the fundamental rules underlying how dopamine modulates different aspects of learning and memory processes. Copyright © 2013 Elsevier Inc. All rights reserved.

Dopamine and extinction: A convergence of theory with fear and reward circuitry

Science.gov (United States)

Abraham, Antony D.; Neve, Kim A.; Lattal, K. Matthew

2014-01-01

Research on dopamine lies at the intersection of sophisticated theoretical and neurobiological approaches to learning and memory. Dopamine has been shown to be critical for many processes that drive learning and memory, including motivation, prediction error, incentive salience, memory consolidation, and response output. Theories of dopamine’s function in these processes have, for the most part, been developed from behavioral approaches that examine learning mechanisms in reward-related tasks. A parallel and growing literature indicates that dopamine is involved in fear conditioning and extinction. These studies are consistent with long-standing ideas about appetitive-aversive interactions in learning theory and they speak to the general nature of cellular and molecular processes that underlie behavior. We review the behavioral and neurobiological literature showing a role for dopamine in fear conditioning and extinction. At a cellular level, we review dopamine signaling and receptor pharmacology, cellular and molecular events that follow dopamine receptor activation, and brain systems in which dopamine functions. At a behavioral level, we describe theories of learning and dopamine function that could describe the fundamental rules underlying how dopamine modulates different aspects of learning and memory processes. PMID:24269353

Development and validation of an item response theory-based Social Responsiveness Scale short form.

Science.gov (United States)

Sturm, Alexandra; Kuhfeld, Megan; Kasari, Connie; McCracken, James T

2017-09-01

Research and practice in autism spectrum disorder (ASD) rely on quantitative measures, such as the Social Responsiveness Scale (SRS), for characterization and diagnosis. Like many ASD diagnostic measures, SRS scores are influenced by factors unrelated to ASD core features. This study further interrogates the psychometric properties of the SRS using item response theory (IRT), and demonstrates a strategy to create a psychometrically sound short form by applying IRT results. Social Responsiveness Scale analyses were conducted on a large sample (N = 21,426) of youth from four ASD databases. Items were subjected to item factor analyses and evaluation of item bias by gender, age, expressive language level, behavior problems, and nonverbal IQ. Item selection based on item psychometric properties, DIF analyses, and substantive validity produced a reduced item SRS short form that was unidimensional in structure, highly reliable (α = .96), and free of gender, age, expressive language, behavior problems, and nonverbal IQ influence. The short form also showed strong relationships with established measures of autism symptom severity (ADOS, ADI-R, Vineland). Degree of association between all measures varied as a function of expressive language. Results identified specific SRS items that are more vulnerable to non-ASD-related traits. The resultant 16-item SRS short form may possess superior psychometric properties compared to the original scale and emerge as a more precise measure of ASD core symptom severity, facilitating research and practice. Future research using IRT is needed to further refine existing measures of autism symptomatology. © 2017 Association for Child and Adolescent Mental Health.

Validating experimental and theoretical Langmuir probe analyses

Science.gov (United States)

Pilling, L. S.; Carnegie, D. A.

2007-08-01

Analysis of Langmuir probe characteristics contains a paradox in that it is unknown a priori which theory is applicable before it is applied. Often theories are assumed to be correct when certain criteria are met although they may not validate the approach used. We have analysed the Langmuir probe data from cylindrical double and single probes acquired from a dc discharge plasma over a wide variety of conditions. This discharge contains a dual-temperature distribution and hence fitting a theoretically generated curve is impractical. To determine the densities, an examination of the current theories was necessary. For the conditions where the probe radius is the same order of magnitude as the Debye length, the gradient expected for orbital-motion limited (OML) is approximately the same as the radial-motion gradients. An analysis of the 'gradients' from the radial-motion theory was able to resolve the differences from the OML gradient value of two. The method was also able to determine whether radial or OML theories applied without knowledge of the electron temperature, or separation of the ion and electron contributions. Only the value of the space potential is necessary to determine the applicable theory.

Non-equilibrium mean-field theories on scale-free networks

International Nuclear Information System (INIS)

Caccioli, Fabio; Dall'Asta, Luca

2009-01-01

Many non-equilibrium processes on scale-free networks present anomalous critical behavior that is not explained by standard mean-field theories. We propose a systematic method to derive stochastic equations for mean-field order parameters that implicitly account for the degree heterogeneity. The method is used to correctly predict the dynamical critical behavior of some binary spin models and reaction–diffusion processes. The validity of our non-equilibrium theory is further supported by showing its relation with the generalized Landau theory of equilibrium critical phenomena on networks

Insulin receptors

International Nuclear Information System (INIS)

Kahn, C.R.; Harrison, L.C.

1988-01-01

This book contains the proceedings on insulin receptors. Part A: Methods for the study of structure and function. Topics covered include: Method for purification and labeling of insulin receptors, the insulin receptor kinase, and insulin receptors on special tissues

Infrared stability of the Yang-Mills theory in the zero-instanton sector

International Nuclear Information System (INIS)

Olesen, P.

1976-12-01

Abstracting the decoupling theorem of Appelquist and Carazzone from perturbation theory it is shown that the Yang-Mills theory is infrared stable in the zero-instanton sector. It is pointed out that the argument is not valid when instantons are present. (Auth.)

3D-QSAR comparative molecular field analysis on opioid receptor antagonists: pooling data from different studies.

Science.gov (United States)

Peng, Youyi; Keenan, Susan M; Zhang, Qiang; Kholodovych, Vladyslav; Welsh, William J

2005-03-10

Three-dimensional quantitative structure-activity relationship (3D-QSAR) models were constructed using comparative molecular field analysis (CoMFA) on a series of opioid receptor antagonists. To obtain statistically significant and robust CoMFA models, a sizable data set of naltrindole and naltrexone analogues was assembled by pooling biological and structural data from independent studies. A process of "leave one data set out", similar to the traditional "leave one out" cross-validation procedure employed in partial least squares (PLS) analysis, was utilized to study the feasibility of pooling data in the present case. These studies indicate that our approach yields statistically significant and highly predictive CoMFA models from the pooled data set of delta, mu, and kappa opioid receptor antagonists. All models showed excellent internal predictability and self-consistency: q(2) = 0.69/r(2) = 0.91 (delta), q(2) = 0.67/r(2) = 0.92 (mu), and q(2) = 0.60/r(2) = 0.96 (kappa). The CoMFA models were further validated using two separate test sets: one test set was selected randomly from the pooled data set, while the other test set was retrieved from other published sources. The overall excellent agreement between CoMFA-predicted and experimental binding affinities for a structurally diverse array of ligands across all three opioid receptor subtypes gives testimony to the superb predictive power of these models. CoMFA field analysis demonstrated that the variations in binding affinity of opioid antagonists are dominated by steric rather than electrostatic interactions with the three opioid receptor binding sites. The CoMFA steric-electrostatic contour maps corresponding to the delta, mu, and kappa opioid receptor subtypes reflected the characteristic similarities and differences in the familiar "message-address" concept of opioid receptor ligands. Structural modifications to increase selectivity for the delta over mu and kappa opioid receptors have been predicted on the

Necessary and sufficient conditions for non-perturbative equivalences of large Nc orbifold gauge theories

International Nuclear Information System (INIS)

Kovtun, Pave; Uensal, Mithat; Yaffe, Laurence G.

2005-01-01

Large N coherent state methods are used to study the relation between U(N c ) gauge theories containing adjoint representation matter fields and their orbifold projections. The classical dynamical systems which reproduce the large N c limits of the quantum dynamics in parent and daughter orbifold theories are compared. We demonstrate that the large N c dynamics of the parent theory, restricted to the subspace invariant under the orbifold projection symmetry, and the large N c dynamics of the daughter theory, restricted to the untwisted sector invariant under 'theory space' permutations, coincide. This implies equality, in the large N c limit, between appropriately identified connected correlation functions in parent and daughter theories, provided the orbifold projection symmetry is not spontaneously broken in the parent theory and the theory space permutation symmetry is not spontaneously broken in the daughter. The necessity of these symmetry realization conditions for the validity of the large N c equivalence is unsurprising, but demonstrating the sufficiency of these conditions is new. This work extends an earlier proof of non-perturbative large N c equivalence which was only valid in the phase of the (lattice regularized) theories continuously connected to large mass and strong coupling

Development and validation of a game addiction scale

NARCIS (Netherlands)

Lemmens, J.S.; Valkenburg, P.M.; Peter, J.

2008-01-01

The aim of this study was to develop and validate a scale to measure computer and videogame addiction. Inspired by earlier theories and research on game and internet addiction, we created 21 items to measure seven criteria for game addiction (i.e., salience, tolerance, mood modification, relapse,

Nuclear Receptor Signaling Atlas: Opening Access to the Biology of Nuclear Receptor Signaling Pathways.

Science.gov (United States)

Becnel, Lauren B; Darlington, Yolanda F; Ochsner, Scott A; Easton-Marks, Jeremy R; Watkins, Christopher M; McOwiti, Apollo; Kankanamge, Wasula H; Wise, Michael W; DeHart, Michael; Margolis, Ronald N; McKenna, Neil J

2015-01-01

Signaling pathways involving nuclear receptors (NRs), their ligands and coregulators, regulate tissue-specific transcriptomes in diverse processes, including development, metabolism, reproduction, the immune response and neuronal function, as well as in their associated pathologies. The Nuclear Receptor Signaling Atlas (NURSA) is a Consortium focused around a Hub website (www.nursa.org) that annotates and integrates diverse 'omics datasets originating from the published literature and NURSA-funded Data Source Projects (NDSPs). These datasets are then exposed to the scientific community on an Open Access basis through user-friendly data browsing and search interfaces. Here, we describe the redesign of the Hub, version 3.0, to deploy "Web 2.0" technologies and add richer, more diverse content. The Molecule Pages, which aggregate information relevant to NR signaling pathways from myriad external databases, have been enhanced to include resources for basic scientists, such as post-translational modification sites and targeting miRNAs, and for clinicians, such as clinical trials. A portal to NURSA's Open Access, PubMed-indexed journal Nuclear Receptor Signaling has been added to facilitate manuscript submissions. Datasets and information on reagents generated by NDSPs are available, as is information concerning periodic new NDSP funding solicitations. Finally, the new website integrates the Transcriptomine analysis tool, which allows for mining of millions of richly annotated public transcriptomic data points in the field, providing an environment for dataset re-use and citation, bench data validation and hypothesis generation. We anticipate that this new release of the NURSA database will have tangible, long term benefits for both basic and clinical research in this field.

Nuclear Receptor Signaling Atlas: Opening Access to the Biology of Nuclear Receptor Signaling Pathways.

Directory of Open Access Journals (Sweden)

Lauren B Becnel

Full Text Available Signaling pathways involving nuclear receptors (NRs, their ligands and coregulators, regulate tissue-specific transcriptomes in diverse processes, including development, metabolism, reproduction, the immune response and neuronal function, as well as in their associated pathologies. The Nuclear Receptor Signaling Atlas (NURSA is a Consortium focused around a Hub website (www.nursa.org that annotates and integrates diverse 'omics datasets originating from the published literature and NURSA-funded Data Source Projects (NDSPs. These datasets are then exposed to the scientific community on an Open Access basis through user-friendly data browsing and search interfaces. Here, we describe the redesign of the Hub, version 3.0, to deploy "Web 2.0" technologies and add richer, more diverse content. The Molecule Pages, which aggregate information relevant to NR signaling pathways from myriad external databases, have been enhanced to include resources for basic scientists, such as post-translational modification sites and targeting miRNAs, and for clinicians, such as clinical trials. A portal to NURSA's Open Access, PubMed-indexed journal Nuclear Receptor Signaling has been added to facilitate manuscript submissions. Datasets and information on reagents generated by NDSPs are available, as is information concerning periodic new NDSP funding solicitations. Finally, the new website integrates the Transcriptomine analysis tool, which allows for mining of millions of richly annotated public transcriptomic data points in the field, providing an environment for dataset re-use and citation, bench data validation and hypothesis generation. We anticipate that this new release of the NURSA database will have tangible, long term benefits for both basic and clinical research in this field.

Effective potential kinetic theory for strongly coupled plasmas

Science.gov (United States)

Baalrud, Scott D.; Daligault, Jérôme

2016-11-01

The effective potential theory (EPT) is a recently proposed method for extending traditional plasma kinetic and transport theory into the strongly coupled regime. Validation from experiments and molecular dynamics simulations have shown it to be accurate up to the onset of liquid-like correlation parameters (corresponding to Γ ≃ 10-50 for the one-component plasma, depending on the process of interest). Here, this theory is briefly reviewed along with comparisons between the theory and molecular dynamics simulations for self-diffusivity and viscosity of the one-component plasma. A number of new results are also provided, including calculations of friction coefficients, energy exchange rates, stopping power, and mobility. The theory is also cast in the Landau and Fokker-Planck kinetic forms, which may prove useful for enabling efficient kinetic computations.

A unified bond theory, probabilistic meso-scale modeling, and experimental validation of deformed steel rebar in normal strength concrete

Science.gov (United States)

Wu, Chenglin

Bond between deformed rebar and concrete is affected by rebar deformation pattern, concrete properties, concrete confinement, and rebar-concrete interfacial properties. Two distinct groups of bond models were traditionally developed based on the dominant effects of concrete splitting and near-interface shear-off failures. Their accuracy highly depended upon the test data sets selected in analysis and calibration. In this study, a unified bond model is proposed and developed based on an analogy to the indentation problem around the rib front of deformed rebar. This mechanics-based model can take into account the combined effect of concrete splitting and interface shear-off failures, resulting in average bond strengths for all practical scenarios. To understand the fracture process associated with bond failure, a probabilistic meso-scale model of concrete is proposed and its sensitivity to interface and confinement strengths are investigated. Both the mechanical and finite element models are validated with the available test data sets and are superior to existing models in prediction of average bond strength (rib spacing-to-height ratio of deformed rebar. It can accurately predict the transition of failure modes from concrete splitting to rebar pullout and predict the effect of rebar surface characteristics as the rib spacing-to-height ratio increases. Based on the unified theory, a global bond model is proposed and developed by introducing bond-slip laws, and validated with testing of concrete beams with spliced reinforcement, achieving a load capacity prediction error of less than 26%. The optimal rebar parameters and concrete cover in structural designs can be derived from this study.

Cultural theory and risk perception: validity and utility explored in the French context

International Nuclear Information System (INIS)

Brenot, J.; Bonnefous, S.; Mays, C.

1996-01-01

Explaining perceived risk can draw upon factors related to the person (e.g. demographics, personality, social/professional status, political orientation), or to the risk source (e.g. health impacts, economic effects). According to Cultural Theory risk perceptions are culturally biased. Wildavsky and Dake operationalised the Cultural Theory with questionnaire scales and found that resulting 'cultural profiles' best predict individual differences in risk perception. A French version of their questionnaire was inserted into a representative national risk opinion survey of May 1993; 1022 adults (age 18 and over) were interviewed. Major results are presented. The four cultural scales (hierarchy, egalitarianism, fatalism and individualism) show high correlations with political orientation as expected, but also with, for example, age, gender, income and education level. However, scale relationships to perception of risk situations (twenty, mainly technological) are not as strong as expected. Sjoeberg found similar results in Sweden. The utility of the existing operationalisation of Cultural Theory for risk perception analysis is discussed. (author)

Cultural theory and risk perception: validity and utility explored in the French context

Energy Technology Data Exchange (ETDEWEB)

Brenot, J.; Bonnefous, S.; Mays, C. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire

1996-12-31

Explaining perceived risk can draw upon factors related to the person (e.g. demographics, personality, social/professional status, political orientation), or to the risk source (e.g. health impacts, economic effects). According to Cultural Theory risk perceptions are culturally biased. Wildavsky and Dake operationalised the Cultural Theory with questionnaire scales and found that resulting `cultural profiles` best predict individual differences in risk perception. A French version of their questionnaire was inserted into a representative national risk opinion survey of May 1993; 1022 adults (age 18 and over) were interviewed. Major results are presented. The four cultural scales (hierarchy, egalitarianism, fatalism and individualism) show high correlations with political orientation as expected, but also with, for example, age, gender, income and education level. However, scale relationships to perception of risk situations (twenty, mainly technological) are not as strong as expected. Sjoeberg found similar results in Sweden. The utility of the existing operationalisation of Cultural Theory for risk perception analysis is discussed. (author).

Introduction to the theory of gravitational radiation

International Nuclear Information System (INIS)

Damour, T.

1987-01-01

In these lectures our attention is restricted to the analytical investigations of the theory of gravitational radiation. There exist already several reviews concerning this topic and, in particular, a recent detailed review, by Thorne, where gravitational radiation theory is put in a form suitable for astrophysical studies. This is why the scope of these lectures is limited to supplement the existing reviews in two ways. First, both the basic concepts of gravitational radiation theory, and the precise conditions, as well as the limitations, of validity of some of the well-known results in this theory are presented. Indeed, as these results have been, or will be, applied in astrophysics, it is important to have clearly in mind both what they mean, and when they can be legitimately applied. Second, a progress report on some of the ongoing analytical research in gravitational radiation theory is presented. 144 references

Eddington-inspired Born-Infeld gravity: nuclear physics constraints and the validity of the continuous fluid approximation

Energy Technology Data Exchange (ETDEWEB)

Avelino, P.P., E-mail: ppavelin@fc.up.pt [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

2012-11-01

In this paper we investigate the classical non-relativistic limit of the Eddington-inspired Born-Infeld theory of gravity. We show that strong bounds on the value of the only additional parameter of the theory κ, with respect to general relativity, may be obtained by requiring that gravity plays a subdominant role compared to electromagnetic interactions inside atomic nuclei. We also discuss the validity of the continuous fluid approximation used in this and other astrophysical and cosmological studies. We argue that although the continuous fluid approximation is expected to be valid in the case of sufficiently smooth density distributions, its use should eventually be validated at a quantum level.

Eddington-inspired Born-Infeld gravity: nuclear physics constraints and the validity of the continuous fluid approximation

International Nuclear Information System (INIS)

Avelino, P.P.

2012-01-01

In this paper we investigate the classical non-relativistic limit of the Eddington-inspired Born-Infeld theory of gravity. We show that strong bounds on the value of the only additional parameter of the theory κ, with respect to general relativity, may be obtained by requiring that gravity plays a subdominant role compared to electromagnetic interactions inside atomic nuclei. We also discuss the validity of the continuous fluid approximation used in this and other astrophysical and cosmological studies. We argue that although the continuous fluid approximation is expected to be valid in the case of sufficiently smooth density distributions, its use should eventually be validated at a quantum level

Personal receptor repertoires: olfaction as a model

Directory of Open Access Journals (Sweden)

Olender Tsviya

2012-08-01

Full Text Available Abstract Background Information on nucleotide diversity along completely sequenced human genomes has increased tremendously over the last few years. This makes it possible to reassess the diversity status of distinct receptor proteins in different human individuals. To this end, we focused on the complete inventory of human olfactory receptor coding regions as a model for personal receptor repertoires. Results By performing data-mining from public and private sources we scored genetic variations in 413 intact OR loci, for which one or more individuals had an intact open reading frame. Using 1000 Genomes Project haplotypes, we identified a total of 4069 full-length polypeptide variants encoded by these OR loci, average of ~10 per locus, constituting a lower limit for the effective human OR repertoire. Each individual is found to harbor as many as 600 OR allelic variants, ~50% higher than the locus count. Because OR neuronal expression is allelically excluded, this has direct effect on smell perception diversity of the species. We further identified 244 OR segregating pseudogenes (SPGs, loci showing both intact and pseudogene forms in the population, twenty-six of which are annotatively “resurrected” from a pseudogene status in the reference genome. Using a custom SNP microarray we validated 150 SPGs in a cohort of 468 individuals, with every individual genome averaging 36 disrupted sequence variations, 15 in homozygote form. Finally, we generated a multi-source compendium of 63 OR loci harboring deletion Copy Number Variations (CNVs. Our combined data suggest that 271 of the 413 intact OR loci (66% are affected by nonfunctional SNPs/indels and/or CNVs. Conclusions These results portray a case of unusually high genetic diversity, and suggest that individual humans have a highly personalized inventory of functional olfactory receptors, a conclusion that might apply to other receptor multigene families.

A systematic review of the reliability and validity of discrete choice experiments in valuing non-market environmental goods

DEFF Research Database (Denmark)

Rokotonarivo, Sarobidy; Schaafsma, Marije; Hockley, Neal

2016-01-01

reliability measures. DCE results were generally consistent with those of other stated preference techniques (convergent validity), but hypothetical bias was common. Evidence supporting theoretical validity (consistency with assumptions of rational choice theory) was limited. In content validity tests, 2...

Nursing Care Interpersonal Relationship Questionnaire: elaboration and validation 1

Science.gov (United States)

Borges, José Wicto Pereira; Moreira, Thereza Maria Magalhães; de Andrade, Dalton Franscisco

2018-01-01

ABSTRACT Objective: to elaborate an instrument for the measurement of the interpersonal relationship in nursing care through the Item Response Theory, and the validation thereof. Method: methodological study, which followed the three poles of psychometry: theoretical, empirical and analytical. The Nursing Care Interpersonal Relationship Questionnaire was developed in light of the Imogene King’s Interpersonal Conceptual Model and the psychometric properties were studied through the Item Response Theory in a sample of 950 patients attended in Primary, Secondary and Tertiary Health Care. Results: the final instrument consisted of 31 items, with Cronbach’s alpha of 0.90 and McDonald’s Omega of 0.92. The parameters of the Item Response Theory demonstrated high discrimination in 28 items, being developed a five-level interpretive scale. At the first level, the communication process begins, gaining a wealth of interaction. Subsequent levels demonstrate qualitatively the points of effectiveness of the interpersonal relationship with the involvement of behaviors related to the concepts of transaction and interaction, followed by the concept of role. Conclusion: the instrument was created and proved to be consistent to measure interpersonal relationship in nursing care, as it presented adequate reliability and validity parameters. PMID:29319743

The special theory of relativity foundations, theory, verification, applications

CERN Document Server

Christodoulides, Costas

2016-01-01

This book offers a comprehensive, university-level introduction to Einstein’s Special Theory of Relativity. In addition to the purely theoretical aspect, emphasis is also given to its historical development as well as to the experiments that preceded the theory and those performed in order to test its validity. The main body of the book consists of chapters on Relativistic Kinematics and Dynamics and their applications, Optics and Electromagnetism. These could be covered in a one-semester course. A more advanced course might include the subjects examined in the other chapters of the book and its appendices. As a textbook, it has some unique characteristics: It provides detailed proofs of the theorems, offers abundant figures and discusses numerous examples. It also includes a number of problems for readers to solve, the complete solutions of which are given at the end of the book. It is primarily intended for use by university students of physics, mathematics and engineering. However, as the mathematics nee...

Moving beyond the Canon: Reflections of a Young African Scholar of Political Theory

Science.gov (United States)

Omar, Ayesha

2016-01-01

In this short paper, I reflect on the issue of what the decolonisation of political theory might constitute. I consider what it would mean to deparochialise and decolonise political theory for it is within the discipline of political theory, that a charge of eurocentrism is particularly valid. First, this is because what we teach and study as…

A clockwork theory

Energy Technology Data Exchange (ETDEWEB)

Giudice, Gian F.; McCullough, Matthew [CERN, Theoretical Physics Department,Geneva (Switzerland)

2017-02-07

The clockwork is a mechanism for generating light particles with exponentially suppressed interactions in theories which contain no small parameters at the fundamental level. We develop a general description of the clockwork mechanism valid for scalars, fermions, gauge bosons, and gravitons. This mechanism can be implemented with a discrete set of new fields or, in its continuum version, through an extra spatial dimension. In both cases the clockwork emerges as a useful tool for model-building applications. Notably, the continuum clockwork offers a solution to the Higgs naturalness problem, which turns out to be the same as in linear dilaton duals of Little String Theory. We also elucidate the similarities and differences of the continuum clockwork with large extra dimensions and warped spaces. All clockwork models, in the discrete and continuum, exhibit novel phenomenology with a distinctive spectrum of closely spaced resonances.

Use of the recognition heuristic depends on the domain's recognition validity, not on the recognition validity of selected sets of objects.

Science.gov (United States)

Pohl, Rüdiger F; Michalkiewicz, Martha; Erdfelder, Edgar; Hilbig, Benjamin E

2017-07-01

According to the recognition-heuristic theory, decision makers solve paired comparisons in which one object is recognized and the other not by recognition alone, inferring that recognized objects have higher criterion values than unrecognized ones. However, success-and thus usefulness-of this heuristic depends on the validity of recognition as a cue, and adaptive decision making, in turn, requires that decision makers are sensitive to it. To this end, decision makers could base their evaluation of the recognition validity either on the selected set of objects (the set's recognition validity), or on the underlying domain from which the objects were drawn (the domain's recognition validity). In two experiments, we manipulated the recognition validity both in the selected set of objects and between domains from which the sets were drawn. The results clearly show that use of the recognition heuristic depends on the domain's recognition validity, not on the set's recognition validity. In other words, participants treat all sets as roughly representative of the underlying domain and adjust their decision strategy adaptively (only) with respect to the more general environment rather than the specific items they are faced with.

''Spare'' alpha 1-adrenergic receptors and the potency of agonists in rat vas deferens

International Nuclear Information System (INIS)

Minneman, K.P.; Abel, P.W.

1984-01-01

The existence of ''spare'' alpha 1-adrenergic receptors in rat vas deferens was examined directly using radioligand binding assays and contractility measurements. Alpha 1-adrenergic receptors in homogenates of rat vas deferens were labeled with [ 125 I]BE 2254 ( 125 IBE). Norepinephrine and other full alpha 1-adrenergic receptor agonists were much less potent in inhibiting 125 IBE binding than in contracting the vas deferens in vitro. Treatment with 300 nM phenoxybenzamine for 10 min to irreversibly inactivate alpha 1-adrenergic receptors caused a large decrease in the potency of full agonists in causing contraction of this tissue and a 23-48% decrease in the maximal contraction observed. Using those data, equilibrium constants for activation (Kact values) of the receptors by agonists were calculated. These Kact values agreed well with the equilibrium binding constants (KD values) determined from displacement of 125 IBE binding. The reduction in alpha 1-adrenergic receptor density following phenoxybenzamine treatment was determined by Scatchard analysis of specific 125 IBE binding sites and compared with the expected reduction (q values) calculated from the agonist dose-response curves before and after phenoxybenzamine treatment. This suggests that phenoxybenzamine functionally inactivates alpha 1-adrenergic receptors at or near the receptor binding site. These experiments suggest that the potencies of agonists in activating alpha 1-adrenergic receptors in rat vas deferens agree well with their potencies in binding to the receptors. The greater potency of agonists in causing contraction may be due to spare receptors in this tissue. The data also demonstrate that phenoxybenzamine irreversibly inactivates alpha 1-adrenergic receptors in rat vas deferens, but that the decrease in receptor density is much smaller than that predicted from receptor theory

A mathematical method for verifying the validity of measured information about the flows of energy resources based on the state estimation theory

Science.gov (United States)

Pazderin, A. V.; Sof'in, V. V.; Samoylenko, V. O.

2015-11-01

Efforts aimed at improving energy efficiency in all branches of the fuel and energy complex shall be commenced with setting up a high-tech automated system for monitoring and accounting energy resources. Malfunctions and failures in the measurement and information parts of this system may distort commercial measurements of energy resources and lead to financial risks for power supplying organizations. In addition, measurement errors may be connected with intentional distortion of measurements for reducing payment for using energy resources on the consumer's side, which leads to commercial loss of energy resource. The article presents a universal mathematical method for verifying the validity of measurement information in networks for transporting energy resources, such as electricity and heat, petroleum, gas, etc., based on the state estimation theory. The energy resource transportation network is represented by a graph the nodes of which correspond to producers and consumers, and its branches stand for transportation mains (power lines, pipelines, and heat network elements). The main idea of state estimation is connected with obtaining the calculated analogs of energy resources for all available measurements. Unlike "raw" measurements, which contain inaccuracies, the calculated flows of energy resources, called estimates, will fully satisfy the suitability condition for all state equations describing the energy resource transportation network. The state equations written in terms of calculated estimates will be already free from residuals. The difference between a measurement and its calculated analog (estimate) is called in the estimation theory an estimation remainder. The obtained large values of estimation remainders are an indicator of high errors of particular energy resource measurements. By using the presented method it is possible to improve the validity of energy resource measurements, to estimate the transportation network observability, to eliminate

Approximate Stream Function wavemaker theory for highly non-linear waves in wave flumes

DEFF Research Database (Denmark)

Zhang, H.W.; Schäffer, Hemming Andreas

2007-01-01

An approximate Stream Function wavemaker theory for highly non-linear regular waves in flumes is presented. This theory is based on an ad hoe unified wave-generation method that combines linear fully dispersive wavemaker theory and wave generation for non-linear shallow water waves. This is done...... by applying a dispersion correction to the paddle position obtained for non-linear long waves. The method is validated by a number of wave flume experiments while comparing with results of linear wavemaker theory, second-order wavemaker theory and Cnoidal wavemaker theory within its range of application....

Udvikling og validering af patientrapporterede spørgeskemaer – del 2

DEFF Research Database (Denmark)

Willert, Cecilie Balslev; Hölmich, Lisbet Rosenkrantz; Thorborg, Kristian

2015-01-01

Test Theory and Item Response Theory, psychometric validation and the measurement properties of a PROM. The latter is based on the COSMIN (consensus-based standards for the selection of health measurement instruments) guidelines, which are developed to assist in development and evaluation of PROMs.......Patient-reported outcome measurements (PROMs) are often questionnaires which provide and rate the patient's point of view in the measurement of subjective clinical phenomena such as pain or quality of life. In the second of two articles we describe field-testing, the psychometric theories Classical...

Are there realistically interpretable local theories?

International Nuclear Information System (INIS)

d'Espagnat, B.

1989-01-01

Although it rests on strongly established proofs, the statement that no realistically interpretable local theory is compatible with some experimentally testable predictions of quantum mechanics seems at first sight to be incompatible with a few general ideas and clear-cut statements occurring in recent theoretical work by Griffiths, Omnes, and Ballentine and Jarrett. It is shown here that in fact none of the developments due to these authors can be considered as a realistically interpretable local theory, so that there is no valid reason for suspecting that the existing proofs of the statement in question are all flawed

Stereochemical study of mouse muscone receptor MOR215-1 and vibrational theory based on statistical physics formalism.

Science.gov (United States)

Ben Khemis, Ismahene; Mechi, Nesrine; Ben Lamine, Abdelmottaleb

2018-02-10

In the biosensor system, olfactory receptor sites could be activated by odorant molecules and then the biological interactions are converted into electrical signals by a signal transduction cascade that leads the toopening of ion channels, generating a current that leads into the cilia and depolarizes the membrane. The aim of this paper is to present a new investigation that allows determining the olfactory band using a monolayer adsorption with identical sites modeling which may also describe the static and the dynamic sensitivities through the expression of the olfactory response. Moreover, knowing the size of receptor site in olfactory sensory neurons provides valuable information about the relationship between molecular structure and biological activity. The determination of microreceptors and mesoreceptors is mostly carried out via physical adsorption and the radius is calculated using the Kelvin equation. The mean values of radius obtained from the maximum of the receptor size distributions peaks are 4 nm for ℓ-muscone and 6 nm for d-muscone. Copyright © 2018. Published by Elsevier Ltd.

Effect of hypothermia on the insulin-receptor interaction in skeletal muscle plasma membranes

International Nuclear Information System (INIS)

Torlinska T, Mackowiak P.; Nogowski L, Kozlik J.

1996-01-01

The aim of the study was to investigate the effect of hypothermia on (125-I)-insulin binding to rat skeletal muscle membranes and to determine whether the decrease in blood insulin concentration could be related to changes in the number or in the affinity of insulin receptor sites according to the down-regulation theory. Rat skeletal muscle membranes were prepared from control, normothermic rats (Tr = 35.6 ± 0.3 degree C) and hypothermic rats (Tr = 26.0 ± 0.5 deg C) and purified according to Havrankowa. In order to determine the kinetic parameters of the hormone-receptor interaction the data from the competition binding studies were analysed by the method of Scatchard using the LIGAND Pc.v.3.1. computer program of Munson and Rodbard. We have shown that under hypothermic conditions insulin receptors number is significantly increased in specific hindlimb skeletal muscles but the changes take place mainly in the low affinity receptors class. The phenomenon probably results from the lack of spare high affinity insulin receptors in skeletal muscle as shown recently by Camps et al. (author). 36 refs., 3 figs, 2 tabs

Affine field theories

International Nuclear Information System (INIS)

Cadavid, A.C.

1989-01-01

The author constructs a non-Abelian field theory by gauging a Kac-Moody algebra, obtaining an infinite tower of interacting vector fields and associated ghosts, that obey slightly modified Feynman rules. She discusses the spontaneous symmetry breaking of such theory via the Higgs mechanism. If the Higgs particle lies in the Cartan subalgebra of the Kac-Moody algebra, the previously massless vectors acquire a mass spectrum that is linear in the Kac-Moody index and has additional fine structure depending on the associated Lie algebra. She proceeds to show that there is no obstacle in implementing the affine extension of supersymmetric Yang-Mills theories. The result is valid in four, six and ten space-time dimensions. Then the affine extension of supergravity is investigated. She discusses only the loop algebra since the affine extension of the super-Poincare algebra appears inconsistent. The construction of the affine supergravity theory is carried out by the group manifold method and leads to an action describing infinite towers of spin 2 and spin 3/2 fields that interact subject to the symmetries of the loop algebra. The equations of motion satisfy the usual consistency check. Finally, she postulates a theory in which both the vector and scalar fields lie in the loop algebra of SO(3). This theory has an expanded soliton sector, and corresponding to the original 't Hooft-Polyakov solitonic solutions she now finds an infinite family of exact, special solutions of the new equations. She also proposes a perturbation method for obtaining an arbitrary solution of those equations for each level of the affine index

Structure of the Nanobody-Stabilized Active State of the Kappa Opioid Receptor.

Science.gov (United States)

Che, Tao; Majumdar, Susruta; Zaidi, Saheem A; Ondachi, Pauline; McCorvy, John D; Wang, Sheng; Mosier, Philip D; Uprety, Rajendra; Vardy, Eyal; Krumm, Brian E; Han, Gye Won; Lee, Ming-Yue; Pardon, Els; Steyaert, Jan; Huang, Xi-Ping; Strachan, Ryan T; Tribo, Alexandra R; Pasternak, Gavril W; Carroll, F Ivy; Stevens, Raymond C; Cherezov, Vadim; Katritch, Vsevolod; Wacker, Daniel; Roth, Bryan L

2018-01-11

The κ-opioid receptor (KOP) mediates the actions of opioids with hallucinogenic, dysphoric, and analgesic activities. The design of KOP analgesics devoid of hallucinatory and dysphoric effects has been hindered by an incomplete structural and mechanistic understanding of KOP agonist actions. Here, we provide a crystal structure of human KOP in complex with the potent epoxymorphinan opioid agonist MP1104 and an active-state-stabilizing nanobody. Comparisons between inactive- and active-state opioid receptor structures reveal substantial conformational changes in the binding pocket and intracellular and extracellular regions. Extensive structural analysis and experimental validation illuminate key residues that propagate larger-scale structural rearrangements and transducer binding that, collectively, elucidate the structural determinants of KOP pharmacology, function, and biased signaling. These molecular insights promise to accelerate the structure-guided design of safer and more effective κ-opioid receptor therapeutics. Copyright © 2017 Elsevier Inc. All rights reserved.

Construct and face validity of a new model for the three-hit theory of depression using PACAP mutant mice on CD1 background.

Science.gov (United States)

Farkas, József; Kovács, László Á; Gáspár, László; Nafz, Anna; Gaszner, Tamás; Ujvári, Balázs; Kormos, Viktória; Csernus, Valér; Hashimoto, Hitoshi; Reglődi, Dóra; Gaszner, Balázs

2017-06-23

Major depression is a common cause of chronic disability. Despite decades of efforts, no equivocally accepted animal model is available for studying depression. We tested the validity of a new model based on the three-hit concept of vulnerability and resilience. Genetic predisposition (hit 1, mutation of pituitary adenylate cyclase-activating polypeptide, PACAP gene), early-life adversity (hit 2, 180-min maternal deprivation, MD180) and chronic variable mild stress (hit 3, CVMS) were combined. Physical, endocrinological, behavioral and functional morphological tools were used to validate the model. Body- and adrenal weight changes as well as corticosterone titers proved that CVMS was effective. Forced swim test indicated increased depression in CVMS PACAP heterozygous (Hz) mice with MD180 history, accompanied by elevated anxiety level in marble burying test. Corticotropin-releasing factor neurons in the oval division of the bed nucleus of the stria terminalis showed increased FosB expression, which was refractive to CVMS exposure in wild-type and Hz mice. Urocortin1 neurons became over-active in CMVS-exposed PACAP knock out (KO) mice with MD180 history, suggesting the contribution of centrally projecting Edinger-Westphal nucleus to the reduced depression and anxiety level of stressed KO mice. Serotoninergic neurons of the dorsal raphe nucleus lost their adaptation ability to CVMS in MD180 mice. In conclusion, the construct and face validity criteria suggest that MD180 PACAP HZ mice on CD1 background upon CVMS may be used as a reliable model for the three-hit theory. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Schur indices, BPS particles, and Argyres-Douglas theories

International Nuclear Information System (INIS)

Córdova, Clay; Shao, Shu-Heng

2016-01-01

We conjecture a precise relationship between the Schur limit of the superconformal index of four-dimensional N=2 field theories, which counts local operators, and the spectrum of BPS particles on the Coulomb branch. We verify this conjecture for the special case of free field theories, N=2 QED, and SU(2) gauge theory coupled to fundamental matter. Assuming the validity of our proposal, we compute the Schur index of all Argyres-Douglas theories. Our answers match expectations from the connection of Schur operators with two-dimensional chiral algebras. Based on our results we propose that the chiral algebra of the generalized Argyres-Douglas theory (A_k_−_1,A_N_−_1) with k and N coprime, is the vacuum sector of the (k,k+N)W_k minimal model, and that the Schur index is the associated vacuum character.

Modifications of Einstein's theory of gravity at large distances

CERN Document Server

2015-01-01

In the last few years modified gravity theories have been proposed as extensions of Einstein's theory of gravity. Their main motivation is to explain the latest cosmological and astrophysical data on dark energy and dark matter. The study of general relativity at small scales has already produced important results (cf e.g. LNP 863 Quantum Gravity and Quantum Cosmology) while its study at large scales is challenging because recent and upcoming observational results will provide important information on the validity of these modified theories.   In this volume, various aspects of modified gravity at large scales will be discussed: high-curvature gravity theories; general scalar-tensor theories; Galileon theories and their cosmological applications; F(R) gravity theories; massive, new massive and topologically massive gravity; Chern-Simons modifications of general relativity (including holographic variants) and higher-spin gravity theories, to name but a few of the most important recent developments.   Edite...

A no-hair theorem for stars in Horndeski theories

Energy Technology Data Exchange (ETDEWEB)

Lehébel, A.; Babichev, E.; Charmousis, C., E-mail: antoine.lehebel@th.u-psud.fr, E-mail: eugeny.babichev@th.u-psud.fr, E-mail: christos.charmousis@th.u-psud.fr [Laboratoire de Physique Théorique, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay (France)

2017-07-01

We consider a generic scalar-tensor theory involving a shift-symmetric scalar field and minimally coupled matter fields. We prove that the Noether current associated with shift-symmetry vanishes in regular, spherically symmetric and static spacetimes. We use this fact to prove the absence of scalar hair for spherically symmetric and static stars in Horndeski and beyond theories. We carefully detail the validity of this no-hair theorem.

Validation and pharmacological characterisation of MK-801-induced locomotor hyperactivity in BALB/C mice as an assay for detection of novel antipsychotics.

Science.gov (United States)

Bradford, Andrea M; Savage, Kevin M; Jones, Declan N C; Kalinichev, Mikhail

2010-10-01

We evaluated locomotor hyperactivity induced in BALB/C mice by an N-methyl-D-aspartate receptor antagonist MK-801 as an assay for the detection of antipsychotic drugs. We assessed the effects of antipsychotic drugs to validate the assay (study 1), selective dopamine and serotonin ligands for pharmacological characterisation of the model (study 2) and a number of compounds with efficacy in models of schizophrenia to understand the predictive validity of the model (study 3). Adult males (n  = 9/group) were pretreated with a test compound, habituated to locomotor activity cages before receiving MK-801 (0.32 mg/kg) and activity recorded for a further 75 or 120 min. In study 1, we tested haloperidol, clozapine, olanzapine, risperidone, ziprasidone, aripiprazole, sertindole and quetiapine. In study 2, we tested SCH23390 (D(1) antagonist), sulpiride (D(2)/D(3) antagonist), raclopride (D(2)/D(3) antagonist), SB-277011 (D(3) antagonist), L-745,870 (D(4) antagonist), WAY100635 (5-HT(1A) antagonist), 8-OH-DPAT (5-HT(1A) agonist), ketanserin (5-HT(2A)/5-HT(2C) antagonist) and SB-242084 (5-HT(2C) antagonist). In study 3, we tested xanomeline (M(1)/M(4) receptor agonist), LY379268 (mGluR2/3 receptor agonist), diazepam (GABA(A) modulator) and thioperamide (H(3) receptor antagonist). All antipsychotics suppressed MK-801-induced hyperactivity in a dose-dependent and specific manner. The effects of antipsychotics appear to be mediated via dopamine D(1), D(2) and 5-HT(2) receptors. Xanomeline, LY379268 and diazepam were active in this assay while thioperamide was not. MK-801-induced hyperactivity in BALB/C mice model of positive symptoms has shown predictive validity with novel compounds acing at M(1)/M(4), mGluR2/3 and GABA(A) receptors and can be used as a screening assay for detection of novel pharmacotherapies targeting those receptors.

Purchasing power parity theory in a model without international trade of goods

OpenAIRE

Läufer, Nikolaus K. A.

1980-01-01

In recent discussions it frequently occurs that the Purchasing Power Parity Theory is identified with Jevons law of one price. By pointing to real world obstacles working against perfect goods arbitrage it is then erroneously concluded that the Purchasing Power Parity Theory cannot be valid while a dinstiction between an absolute version and a relative version of the Purchasing Power Parity Theory is neglected. In the present paper it is shown that the Purchasing Power Parity Theory in the re...

Pattern activation/recognition theory of mind.

Science.gov (United States)

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.

A signal detection-item response theory model for evaluating neuropsychological measures.

Science.gov (United States)

Thomas, Michael L; Brown, Gregory G; Gur, Ruben C; Moore, Tyler M; Patt, Virginie M; Risbrough, Victoria B; Baker, Dewleen G

2018-02-05

Models from signal detection theory are commonly used to score neuropsychological test data, especially tests of recognition memory. Here we show that certain item response theory models can be formulated as signal detection theory models, thus linking two complementary but distinct methodologies. We then use the approach to evaluate the validity (construct representation) of commonly used research measures, demonstrate the impact of conditional error on neuropsychological outcomes, and evaluate measurement bias. Signal detection-item response theory (SD-IRT) models were fitted to recognition memory data for words, faces, and objects. The sample consisted of U.S. Infantry Marines and Navy Corpsmen participating in the Marine Resiliency Study. Data comprised item responses to the Penn Face Memory Test (PFMT; N = 1,338), Penn Word Memory Test (PWMT; N = 1,331), and Visual Object Learning Test (VOLT; N = 1,249), and self-report of past head injury with loss of consciousness. SD-IRT models adequately fitted recognition memory item data across all modalities. Error varied systematically with ability estimates, and distributions of residuals from the regression of memory discrimination onto self-report of past head injury were positively skewed towards regions of larger measurement error. Analyses of differential item functioning revealed little evidence of systematic bias by level of education. SD-IRT models benefit from the measurement rigor of item response theory-which permits the modeling of item difficulty and examinee ability-and from signal detection theory-which provides an interpretive framework encompassing the experimentally validated constructs of memory discrimination and response bias. We used this approach to validate the construct representation of commonly used research measures and to demonstrate how nonoptimized item parameters can lead to erroneous conclusions when interpreting neuropsychological test data. Future work might include the

Entropy Evaluation Based on Value Validity

Directory of Open Access Journals (Sweden)

Tarald O. Kvålseth

2014-09-01

Full Text Available Besides its importance in statistical physics and information theory, the Boltzmann-Shannon entropy S has become one of the most widely used and misused summary measures of various attributes (characteristics in diverse fields of study. It has also been the subject of extensive and perhaps excessive generalizations. This paper introduces the concept and criteria for value validity as a means of determining if an entropy takes on values that reasonably reflect the attribute being measured and that permit different types of comparisons to be made for different probability distributions. While neither S nor its relative entropy equivalent S* meet the value-validity conditions, certain power functions of S and S* do to a considerable extent. No parametric generalization offers any advantage over S in this regard. A measure based on Euclidean distances between probability distributions is introduced as a potential entropy that does comply fully with the value-validity requirements and its statistical inference procedure is discussed.

Death Receptor 6 Promotes Wallerian Degeneration in Peripheral Axons.

Science.gov (United States)

Gamage, Kanchana K; Cheng, Irene; Park, Rachel E; Karim, Mardeen S; Edamura, Kazusa; Hughes, Christopher; Spano, Anthony J; Erisir, Alev; Deppmann, Christopher D

2017-03-20

Axon degeneration during development is required to sculpt a functional nervous system and is also a hallmark of pathological insult, such as injury [1, 2]. Despite similar morphological characteristics, very little overlap in molecular mechanisms has been reported between pathological and developmental degeneration [3-5]. In the peripheral nervous system (PNS), developmental axon pruning relies on receptor-mediated extrinsic degeneration mechanisms to determine which axons are maintained or degenerated [5-7]. Receptors have not been implicated in Wallerian axon degeneration; instead, axon autonomous, intrinsic mechanisms are thought to be the primary driver for this type of axon disintegration [8-10]. Here we survey the role of neuronally expressed, paralogous tumor necrosis factor receptor super family (TNFRSF) members in Wallerian degeneration. We find that an orphan receptor, death receptor 6 (DR6), is required to drive axon degeneration after axotomy in sympathetic and sensory neurons cultured in microfluidic devices. We sought to validate these in vitro findings in vivo using a transected sciatic nerve model. Consistent with the in vitro findings, DR6 -/- animals displayed preserved axons up to 4 weeks after injury. In contrast to phenotypes observed in Wld s and Sarm1 -/- mice, preserved axons in DR6 -/- animals display profound myelin remodeling. This indicates that deterioration of axons and myelin after axotomy are mechanistically distinct processes. Finally, we find that JNK signaling after injury requires DR6, suggesting a link between this novel extrinsic pathway and the axon autonomous, intrinsic pathways that have become established for Wallerian degeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is the isolated ligand binding domain a good model of the domain in the native receptor?

Science.gov (United States)

Deming, Dustin; Cheng, Qing; Jayaraman, Vasanthi

2003-05-16

Numerous studies have used the atomic level structure of the isolated ligand binding domain of the glutamate receptor to elucidate the agonist-induced activation and desensitization processes in this group of proteins. However, no study has demonstrated the structural equivalence of the isolated ligand binding fragments and the protein in the native receptor. In this report, using visible absorption spectroscopy we show that the electronic environment of the antagonist 6-cyano-7-nitro-2,3-dihydroxyquinoxaline is identical for the isolated protein and the native glutamate receptors expressed in cells. Our results hence establish that the local structure of the ligand binding site is the same in the two proteins and validate the detailed structure-function relationships that have been developed based on a comparison of the structure of the isolated ligand binding domain and electrophysiological consequences in the native receptor.

Towards an energetic theory of brittle fracture

International Nuclear Information System (INIS)

Francfort, G.; Marigo, J.J.

2002-01-01

The drawbacks of the classical theory of brittle fracture, based on Griffith's criterion, - a notion of critical energy release rate -, and a fracture toughness k, are numerous (think for instance the issue of crack initiation) and penalize its validity as a good model. Are all attempts at building a macroscopic theory of fracture doomed? The variety and complexity of micro-mechanical phenomena would suggest that this is indeed the case. We believe however that structural effects still preside over fracture and consequently propose to modify slightly Griffith theory without altering its fundamental components so that it becomes amenable to the widest range of situations. The examples presented here will demonstrate that a revisited energetic framework is a sound basis for a theory which can be used at the engineering level and which reconciles seemingly contradictory viewpoints. (authors)

Weak turbulence theory for beam-plasma interaction

Science.gov (United States)

Yoon, Peter H.

2018-01-01

The kinetic theory of weak plasma turbulence, of which Ronald C. Davidson was an important early pioneer [R. C. Davidson, Methods in Nonlinear Plasma Theory, (Academic Press, New York, 1972)], is a venerable and valid theory that may be applicable to a large number of problems in both laboratory and space plasmas. This paper applies the weak turbulence theory to the problem of gentle beam-plasma interaction and Langmuir turbulence. It is shown that the beam-plasma interaction undergoes various stages of physical processes starting from linear instability, to quasilinear saturation, to mode coupling that takes place after the quasilinear stage, followed by a state of quasi-static "turbulent equilibrium." The long term quasi-equilibrium stage is eventually perturbed by binary collisional effects in order to bring the plasma to a thermodynamic equilibrium with increased entropy.

Soft theorems from conformal field theory

International Nuclear Information System (INIS)

Lipstein, Arthur E.

2015-01-01

Strominger and collaborators recently proposed that soft theorems for gauge and gravity amplitudes can be interpreted as Ward identities of a 2d CFT at null infinity. In this paper, we will consider a specific realization of this CFT known as ambitwistor string theory, which describes 4d Yang-Mills and gravity with any amount of supersymmetry. Using 4d ambtwistor string theory, we derive soft theorems in the form of an infinite series in the soft momentum which are valid to subleading order in gauge theory and sub-subleading order in gravity. Furthermore, we describe how the algebra of soft limits can be encoded in the braiding of soft vertex operators on the worldsheet and point out a simple relation between soft gluon and soft graviton vertex operators which suggests an interesting connection to color-kinematics duality. Finally, by considering ambitwistor string theory on a genus one worldsheet, we compute the 1-loop correction to the subleading soft graviton theorem due to infrared divergences.

Towards a second law for Lovelock theories

Energy Technology Data Exchange (ETDEWEB)

Bhattacharyya, Sayantani [Indian Institute of Technology Kanpur,Kanpur 208016 (India); Haehl, Felix M. [Department of Physics and Astronomy, University of British Columbia,6224 Agricultural Road, Vancouver, B.C. V6T 1Z1 (Canada); Kundu, Nilay [Center for Gravitational Physics, Yukawa Institute for Theoretical Physics (YITP), Kyoto University,Kyoto 606-8502 (Japan); Loganayagam, R. [International Centre for Theoretical Sciences (ICTS-TIFR), Shivakote, Hesaraghatta Hobli, Bengaluru 560089 (India); Rangamani, Mukund [Center for Quantum Mathematics and Physics (QMAP), Department of Physics, University of California,Davis, CA 95616 (United States)

2017-03-13

In classical general relativity described by Einstein-Hilbert gravity, black holes behave as thermodynamic objects. In particular, the laws of black hole mechanics can be interpreted as laws of thermodynamics. The first law of black hole mechanics extends to higher derivative theories via the Noether charge construction of Wald. One also expects the statement of the second law, which in Einstein-Hilbert theory owes to Hawking’s area theorem, to extend to higher derivative theories. To argue for this however one needs a notion of entropy for dynamical black holes, which the Noether charge construction does not provide. We propose such an entropy function for the family of Lovelock theories, treating the higher derivative terms as perturbations to the Einstein-Hilbert theory. Working around a dynamical black hole solution, and making no assumptions about the amplitude of departure from equilibrium, we construct a candidate entropy functional valid to all orders in the low energy effective field theory. This entropy functional satisfies a second law, modulo a certain subtle boundary term, which deserves further investigation in non-spherically symmetric situations.

Towards a second law for Lovelock theories

Science.gov (United States)

Bhattacharyya, Sayantani; Haehl, Felix M.; Kundu, Nilay; Loganayagam, R.; Rangamani, Mukund

2017-03-01

In classical general relativity described by Einstein-Hilbert gravity, black holes behave as thermodynamic objects. In particular, the laws of black hole mechanics can be interpreted as laws of thermodynamics. The first law of black hole mechanics extends to higher derivative theories via the Noether charge construction of Wald. One also expects the statement of the second law, which in Einstein-Hilbert theory owes to Hawking's area theorem, to extend to higher derivative theories. To argue for this however one needs a notion of entropy for dynamical black holes, which the Noether charge construction does not provide. We propose such an entropy function for the family of Lovelock theories, treating the higher derivative terms as perturbations to the Einstein-Hilbert theory. Working around a dynamical black hole solution, and making no assumptions about the amplitude of departure from equilibrium, we construct a candidate entropy functional valid to all orders in the low energy effective field theory. This entropy functional satisfies a second law, modulo a certain subtle boundary term, which deserves further investigation in non-spherically symmetric situations.

Dragons and Dinosaurs: Directing Inquiry in Biology Using the Notions of "Milieu" and "Validation"

Science.gov (United States)

Achiam, Marianne; Solberg, Jan; Evans, Robert

2013-01-01

This article describes how inquiry teaching can be directed towards specific content learning goals while allowing for student exploration and validation of hypotheses. Drawing from the Theory of Didactical Situations, the concepts of "milieu" and "validation" are illustrated through two sample biology lessons designed to engage and challenge…

Testing special relativity theory using Compton scattering

International Nuclear Information System (INIS)

Contreras S, H.; Hernandez A, L.; Baltazar R, A.; Escareno J, E.; Mares E, C. A.; Hernandez V, C.; Vega C, H. R.

2010-10-01

The validity of the special relativity theory has been tested using the Compton scattering. Since 1905 several experiments has been carried out to show that time, mass, and length change with the velocity, in this work the Compton scattering has been utilized as a simple way to show the validity to relativity. The work was carried out through Monte Carlo calculations and experiments with different gamma-ray sources and a gamma-ray spectrometer with a 3 x 3 NaI (Tl) detector. The pulse-height spectra were collected and the Compton edge was observed. This information was utilized to determine the relationship between the electron's mass and energy using the Compton -knee- position, the obtained results were contrasted with two collision models between photon and electron, one model was built using the classical physics and another using the special relativity theory. It was found that calculations and experiments results fit to collision model made using the special relativity. (Author)

Nonabelian noncommutative gauge theory via noncommutative extra dimensions

Energy Technology Data Exchange (ETDEWEB)

Jurco, Branislav E-mail: jurco@theorie.physik.uni-muenchen.de; Schupp, Peter E-mail: schupp@theorie.physik.uni-muenchen.de; Wess, Julius E-mail: wess@theorie.physik.uni-muenchen.de

2001-06-18

The concept of covariant coordinates on noncommutative spaces leads directly to gauge theories with generalized noncommutative gauge fields of the type that arises in string theory with background B-fields. The theory is naturally expressed in terms of cochains in an appropriate cohomology; we discuss how it fits into the framework of projective modules. The equivalence of star products that arise from the background field with and without fluctuations and Kontsevich's formality theorem allow an explicitly construction of a map that relates ordinary gauge theory and noncommutative gauge theory (Seiberg-Witten map). As application we show the exact equality of the Dirac-Born-Infeld action with B-field in the commutative setting and its semi-noncommutative cousin in the intermediate picture. Using noncommutative extra dimensions the construction is extended to noncommutative nonabelian gauge theory for arbitrary gauge groups; an explicit map between abelian and nonabelian gauge fields is given. All constructions are also valid for non-constant B-field, Poisson structure and metric.

Nonabelian noncommutative gauge theory via noncommutative extra dimensions

International Nuclear Information System (INIS)

Jurco, Branislav; Schupp, Peter; Wess, Julius

2001-01-01

The concept of covariant coordinates on noncommutative spaces leads directly to gauge theories with generalized noncommutative gauge fields of the type that arises in string theory with background B-fields. The theory is naturally expressed in terms of cochains in an appropriate cohomology; we discuss how it fits into the framework of projective modules. The equivalence of star products that arise from the background field with and without fluctuations and Kontsevich's formality theorem allow an explicitly construction of a map that relates ordinary gauge theory and noncommutative gauge theory (Seiberg-Witten map). As application we show the exact equality of the Dirac-Born-Infeld action with B-field in the commutative setting and its semi-noncommutative cousin in the intermediate picture. Using noncommutative extra dimensions the construction is extended to noncommutative nonabelian gauge theory for arbitrary gauge groups; an explicit map between abelian and nonabelian gauge fields is given. All constructions are also valid for non-constant B-field, Poisson structure and metric

Kelsen and the theory of interpretation humpty dumpty

Directory of Open Access Journals (Sweden)

Samuel Moreira Gouveia

2016-04-01

Full Text Available This article aims to draw the consequences of the theoretical development of the concepts of kelsenian theory - focused on the relationship between "validity" and "interpretation "- to observe the motivation this kind of criticism leads to the necessary consideration about the existence of a plurality of legal actors. It takes the theoretical resizing done by Michel Troper as a paradigm of the theoretical development that has its starting point from the unsatisfactory reply given by the pyramidal hierarchy which kelseniana theory is based. Finally, collates the various theories face the impossibility of existence of an "autonomous language", as described by Wittgenstein’s Philosophical Investigations.

Reduced striatal D2 receptor binding in myoclonus-dystonia

International Nuclear Information System (INIS)

Beukers, R.J.; Weisscher, N.; Tijssen, M.A.J.; Booij, J.; Zijlstra, F.; Amelsvoort, T.A.M.J. van

2009-01-01

To study striatal dopamine D 2 receptor availability in DYT11 mutation carriers of the autosomal dominantly inherited disorder myoclonus-dystonia (M-D). Fifteen DYT11 mutation carriers (11 clinically affected) and 15 age- and sex-matched controls were studied using 123 I-IBZM SPECT. Specific striatal binding ratios were calculated using standard templates for striatum and occipital areas. Multivariate analysis with corrections for ageing and smoking showed significantly lower specific striatal to occipital IBZM uptake ratios (SORs) both in the left and right striatum in clinically affected patients and also in all DYT11 mutation carriers compared to control subjects. Our findings are consistent with the theory of reduced dopamine D 2 receptor (D2R) availability in dystonia, although the possibility of increased endogenous dopamine, and consequently, competitive D2R occupancy cannot be ruled out. (orig.)

Receptor visualization and the atomic bomb. A historical account of the development of the chemical neuroanatomy of receptors for neurotransmitters and drugs during the Cold War.

Science.gov (United States)

Palacios, J M; Mengod, G

2018-03-01

chemical concept to their physical reality as gene products. Important steps were the introduction in the 70's of radioligand binding techniques and the cloning of receptor genes in the 80's. Receptors were first visualized using radioligands and autoradiography, and analyzed with the newly developed computer-assisted image analysis systems. Using Positron Emission Tomography transmitters and receptors were visualized in living human brain. The cloning of receptor genes allowed the use of in situ hybridization histochemistry and immunohistochemistry to visualize with the light and electron microscopes the receptor mRNAs and proteins. The results showed the wide heterogeneity of receptors and the diversity of mode of signal transmission, synaptic and extra-synaptic, again radically modifying the early views of neurotransmission. During the entire period the interplay between basic science and Psychopharmacology and Psychiatry generated different transmitter or receptor-based theories of brain drug action. These concepts and technologies also changed the way new drugs were discovered and developed. At the end of the period, a number of declines in these theories, the use of certain tools and the ability to generate new diagnostics and treatments, the end of an era and the beginning of a new one in the research of how the brain functions. Copyright © 2017 Elsevier B.V. All rights reserved.

Classical and non-classical effective medium theories: New perspectives

International Nuclear Information System (INIS)

Tsukerman, Igor

2017-01-01

Highlights: • Advanced non-asymptotic and nonlocal homogenization theories of metamaterials, valid in electrostatics and electrodynamics. • Classical theories (Clausius–Mossotti, Lorenz–Lorentz, Maxwell Garnett) fit well into the proposed framework. • Nonlocal effects can be included in the model, making order-of-magnitude accuracy improvements possible. • A challenging problem for future research is to determine what effective tensors are attainable for given constituents of a metamaterial. - Abstract: Future research in electrodynamics of periodic electromagnetic composites (metamaterials) can be expected to produce sophisticated homogenization theories valid for any composition and size of the lattice cell. The paper outlines a promising path in that direction, leading to non-asymptotic and nonlocal homogenization models, and highlights aspects of homogenization that are often overlooked: the finite size of the sample and the role of interface boundaries. Classical theories (e.g. Clausius–Mossotti, Maxwell Garnett), while originally derived from a very different set of ideas, fit well into the proposed framework. Nonlocal effects can be included in the model, making an order-of-magnitude accuracy improvements possible. One future challenge is to determine what effective parameters can or cannot be obtained for a given set of constituents of a metamaterial lattice cell, thereby delineating the possible from the impossible in metamaterial design.

Classical and non-classical effective medium theories: New perspectives

Energy Technology Data Exchange (ETDEWEB)

Tsukerman, Igor, E-mail: igor@uakron.edu

2017-05-18

Highlights: • Advanced non-asymptotic and nonlocal homogenization theories of metamaterials, valid in electrostatics and electrodynamics. • Classical theories (Clausius–Mossotti, Lorenz–Lorentz, Maxwell Garnett) fit well into the proposed framework. • Nonlocal effects can be included in the model, making order-of-magnitude accuracy improvements possible. • A challenging problem for future research is to determine what effective tensors are attainable for given constituents of a metamaterial. - Abstract: Future research in electrodynamics of periodic electromagnetic composites (metamaterials) can be expected to produce sophisticated homogenization theories valid for any composition and size of the lattice cell. The paper outlines a promising path in that direction, leading to non-asymptotic and nonlocal homogenization models, and highlights aspects of homogenization that are often overlooked: the finite size of the sample and the role of interface boundaries. Classical theories (e.g. Clausius–Mossotti, Maxwell Garnett), while originally derived from a very different set of ideas, fit well into the proposed framework. Nonlocal effects can be included in the model, making an order-of-magnitude accuracy improvements possible. One future challenge is to determine what effective parameters can or cannot be obtained for a given set of constituents of a metamaterial lattice cell, thereby delineating the possible from the impossible in metamaterial design.

Glutamate Receptors within the Mesolimbic Dopamine System Mediate Alcohol Relapse Behavior.

Science.gov (United States)

Eisenhardt, Manuela; Leixner, Sarah; Luján, Rafael; Spanagel, Rainer; Bilbao, Ainhoa

2015-11-25

Glutamatergic input within the mesolimbic dopamine (DA) pathway plays a critical role in the development of addictive behavior. Although this is well established for some drugs of abuse, it is not known whether glutamate receptors within the mesolimbic system are involved in mediating the addictive properties of chronic alcohol use. Here we evaluated the contribution of mesolimbic NMDARs and AMPARs in mediating alcohol-seeking responses induced by environmental stimuli and relapse behavior using four inducible mutant mouse lines lacking the glutamate receptor genes Grin1 or Gria1 in either DA transporter (DAT) or D1R-expressing neurons. We first demonstrate the lack of GluN1 or GluA1 in either DAT- or D1R-expressing neurons in our mutant mouse lines by colocalization studies. We then show that GluN1 and GluA1 receptor subunits within these neuronal subpopulations mediate the alcohol deprivation effect, while having no impact on context- plus cue-induced reinstatement of alcohol-seeking behavior. We further validated these results pharmacologically by demonstrating similar reductions in the alcohol deprivation effect after infusion of the NMDAR antagonist memantine into the nucleus accumbens and ventral tegmental area of control mice, and a rescue of the mutant phenotype via pharmacological potentiation of AMPAR activity using aniracetam. In conclusion, dopamine neurons as well as D1R-expressing medium spiny neurons and their glutamatergic inputs via NMDARs and AMPARs act in concert to influence relapse responses. These results provide a neuroanatomical and molecular substrate for relapse behavior and emphasize the importance of glutamatergic drugs in modulating relapse behavior. Here we provide genetic and pharmacological evidence that glutamate receptors within the mesolimbic dopamine system play an essential role in alcohol relapse. Using various inducible and site-specific transgenic mouse models and pharmacological validation experiments, we show that critical

The interleukin-4 receptor: signal transduction by a hematopoietin receptor.

Science.gov (United States)

Keegan, A D; Pierce, J H

1994-02-01

Over the last several years, the receptors for numerous cytokines have been molecularly characterized. Analysis of their amino acid sequences shows that some of these receptors bear certain motifs in their extracellular domains that define a family of receptors called the Hematopoietin receptor superfamily. Significant advances in characterizing the structure, function, and mechanisms of signal transduction have been made for several members of this family. The purpose of this review is to discuss the recent advances made for one of the family members, the interleukin (IL) 4 receptor. Other receptor systems have recently been reviewed elsewhere. The IL-4 receptor consists of, at the minimum, the cloned 140 kDa IL-4-binding chain with the potential for associating with other chains. The IL-4 receptor transduces its signal by activating a tyrosine kinase that phosphorylates cellular substrates, including the receptor itself, and the 170 kDa substrate called 4PS. Phosphorylated 4PS interacts with the SH2 domain of the enzyme PI-3'-kinase and increases its enzymatic activity. These early events in the IL-4 receptor initiated signaling pathway may trigger a series of signals that will ultimately lead to an IL-4 specific biologic outcome.

Dislocation-mediated strain hardening in tungsten: Thermo-mechanical plasticity theory and experimental validation

Science.gov (United States)

Terentyev, Dmitry; Xiao, Xiazi; Dubinko, A.; Bakaeva, A.; Duan, Huiling

2015-12-01

A self-consistent thermo-mechanical model to study the strain-hardening behavior of polycrystalline tungsten was developed and validated by a dedicated experimental route. Dislocation-dislocation multiplication and storage, as well dislocation-grain boundary (GB) pinning were the major mechanisms underlying the evolution of plastic deformation, thus providing a link between the strain hardening behavior and material's microstructure. The microstructure of the polycrystalline tungsten samples has been thoroughly investigated by scanning and electron microscopy. The model was applied to compute stress-strain loading curves of commercial tungsten grades, in the as-received and as-annealed states, in the temperature range of 500-1000 °C. Fitting the model to the independent experimental results obtained using a single crystal and as-received polycrystalline tungsten, the model demonstrated its capability to predict the deformation behavior of as-annealed samples in a wide temperature range and applied strain. The relevance of the dislocation-mediated plasticity mechanisms used in the model have been validated using transmission electron microscopy examination of the samples deformed up to different amounts of strain. On the basis of the experimental validation, the limitations of the model are determined and discussed.

Competency-Based Training and Simulation: Making a "Valid" Argument.

Science.gov (United States)

Noureldin, Yasser A; Lee, Jason Y; McDougall, Elspeth M; Sweet, Robert M

2018-02-01

The use of simulation as an assessment tool is much more controversial than is its utility as an educational tool. However, without valid simulation-based assessment tools, the ability to objectively assess technical skill competencies in a competency-based medical education framework will remain challenging. The current literature in urologic simulation-based training and assessment uses a definition and framework of validity that is now outdated. This is probably due to the absence of awareness rather than an absence of comprehension. The following review article provides the urologic community an updated taxonomy on validity theory as it relates to simulation-based training and assessments and translates our simulation literature to date into this framework. While the old taxonomy considered validity as distinct subcategories and focused on the simulator itself, the modern taxonomy, for which we translate the literature evidence, considers validity as a unitary construct with a focus on interpretation of simulator data/scores.

What Is True Halving in the Payoff Matrix of Game Theory?

Science.gov (United States)

Ito, Hiromu; Katsumata, Yuki; Hasegawa, Eisuke; Yoshimura, Jin

2016-01-01

In game theory, there are two social interpretations of rewards (payoffs) for decision-making strategies: (1) the interpretation based on the utility criterion derived from expected utility theory and (2) the interpretation based on the quantitative criterion (amount of gain) derived from validity in the empirical context. A dynamic decision theory has recently been developed in which dynamic utility is a conditional (state) variable that is a function of the current wealth of a decision maker. We applied dynamic utility to the equal division in dove-dove contests in the hawk-dove game. Our results indicate that under the utility criterion, the half-share of utility becomes proportional to a player's current wealth. Our results are consistent with studies of the sense of fairness in animals, which indicate that the quantitative criterion has greater validity than the utility criterion. We also find that traditional analyses of repeated games must be reevaluated.

Charge and pairing dynamics in the attractive Hubbard model: Mode coupling and the validity of linear-response theory

Science.gov (United States)

Bünemann, Jörg; Seibold, Götz

2017-12-01

Pump-probe experiments have turned out as a powerful tool in order to study the dynamics of competing orders in a large variety of materials. The corresponding analysis of the data often relies on standard linear-response theory generalized to nonequilibrium situations. Here we examine the validity of such an approach for the charge and pairing response of systems with charge-density wave and (or) superconducting (SC) order. Our investigations are based on the attractive Hubbard model which we study within the time-dependent Hartree-Fock approximation. In particular, we calculate the quench and pump-probe dynamics for SC and charge order parameters in order to analyze the frequency spectra and the coupling of the probe field to the specific excitations. Our calculations reveal that the "linear-response assumption" is justified for small to moderate nonequilibrium situations (i.e., pump pulses) in the case of a purely charge-ordered ground state. However, the pump-probe dynamics on top of a superconducting ground state is determined by phase and amplitude modes which get coupled far from the equilibrium state indicating the failure of the linear-response assumption.

11C-NS14492 as a novel PET radioligand for imaging cerebral alpha7 nicotinic acetylcholine receptors: in vivo evaluation and drug occupancy measurements

DEFF Research Database (Denmark)

Ettrup, Anders; Mikkelsen, Jens D; Lehel, Szabolcs

2011-01-01

Small-molecule α(7) nicotinic acetylcholine receptor (α(7)nAChR) agonists are currently validated for use as treatment for cognitive disturbances in schizophrenia and in Alzheimer disease. A suitable radiolabeled α(7)nAChR PET tracer would be important for in vivo quantification of α(7)nAChR bind......Small-molecule α(7) nicotinic acetylcholine receptor (α(7)nAChR) agonists are currently validated for use as treatment for cognitive disturbances in schizophrenia and in Alzheimer disease. A suitable radiolabeled α(7)nAChR PET tracer would be important for in vivo quantification of α(7)n...

11C-NS14492 as a novel PET radioligand for imaging cerebral alpha7 nicotinic acetylcholine receptors: in vivo evaluation and drug occupancy measurements

DEFF Research Database (Denmark)

Ettrup, Anders; Mikkelsen, Jens D; Lehel, Szabolcs

2011-01-01

Small-molecule a(7) nicotinic acetylcholine receptor (a(7)nAChR) agonists are currently validated for use as treatment for cognitive disturbances in schizophrenia and in Alzheimer disease. A suitable radiolabeled a(7)nAChR PET tracer would be important for in vivo quantification of a(7)nAChR bind......Small-molecule a(7) nicotinic acetylcholine receptor (a(7)nAChR) agonists are currently validated for use as treatment for cognitive disturbances in schizophrenia and in Alzheimer disease. A suitable radiolabeled a(7)nAChR PET tracer would be important for in vivo quantification of a(7)n...

Developing and Validating a Science Notebook Rubric for Fifth-Grade Non-Mainstream Students

Science.gov (United States)

Huerta, Margarita; Lara-Alecio, Rafael; Tong, Fuhui; Irby, Beverly J.

2014-07-01

We present the development and validation of a science notebook rubric intended to measure the academic language and conceptual understanding of non-mainstream students, specifically fifth-grade male and female economically disadvantaged Hispanic English language learner (ELL) and African-American or Hispanic native English-speaking students. The science notebook rubric is based on two main constructs: academic language and conceptual understanding. The constructs are grounded in second-language acquisition theory and theories of writing and conceptual understanding. We established content validity and calculated reliability measures using G theory and percent agreement (for comparison) with a sample of approximately 144 unique science notebook entries and 432 data points. Results reveal sufficient reliability estimates, indicating that the instrument is promising for use in future research studies including science notebooks in classrooms with populations of economically disadvantaged Hispanic ELL and African-American or Hispanic native English-speaking students.

Development and Initial Validation of the Need Satisfaction and Need Support at Work Scales: A Validity-Focused Approach

Directory of Open Access Journals (Sweden)

Susanne Tafvelin

2018-01-01

Full Text Available Although the relevance of employee need satisfaction and manager need support have been examined, the integration of self-determination theory (SDT into work and organizational psychology has been hampered by the lack of validated measures. The purpose of the current study was to develop and validate measures of employees’ perception of need satisfaction (NSa-WS and need support (NSu-WS at work that were grounded in SDT. We used three Swedish samples (total 'N' = 1,430 to develop and validate our scales. We used a confirmatory approach including expert panels to assess item content relevance, confirmatory factor analysis for factorial validity, and associations with theoretically warranted outcomes to assess criterion-related validity. Scale reliability was also assessed. We found evidence of content, factorial, and criterion-related validity of our two scales of need satisfaction and need support at work. Further, the scales demonstrated high internal consistency. Our newly developed scales may be used in research and practice to further our understanding regarding how satisfaction and support of employee basic needs influence employee motivation, performance, and well-being. Our study makes a contribution to the current literature by providing (1 scales that are specifically designed for the work context, (2 an example of how expert panels can be used to assess content validity, and (3 testing of theoretically derived hypotheses that, although SDT is built on them, have not been examined before.

Glucagon-like peptide-1 receptor ligand interactions: structural cross talk between ligands and the extracellular domain.

Directory of Open Access Journals (Sweden)

Graham M West

Full Text Available Activation of the glucagon-like peptide-1 receptor (GLP-1R in pancreatic β-cells potentiates insulin production and is a current therapeutic target for the treatment of type 2 diabetes mellitus (T2DM. Like other class B G protein-coupled receptors (GPCRs, the GLP-1R contains an N-terminal extracellular ligand binding domain. N-terminal truncations on the peptide agonist generate antagonists capable of binding to the extracellular domain, but not capable of activating full length receptor. The main objective of this study was to use Hydrogen/deuterium exchange (HDX to identify how the amide hydrogen bonding network of peptide ligands and the extracellular domain of GLP-1R (nGLP-1R were altered by binding interactions and to then use this platform to validate direct binding events for putative GLP-1R small molecule ligands. The HDX studies presented here for two glucagon-like peptide-1 receptor (GLP-1R peptide ligands indicates that the antagonist exendin-4[9-39] is significantly destabilized in the presence of nonionic detergents as compared to the agonist exendin-4. Furthermore, HDX can detect stabilization of exendin-4 and exendin-4[9-39] hydrogen bonding networks at the N-terminal helix [Val19 to Lys27] upon binding to the N-terminal extracellular domain of GLP-1R (nGLP-1R. In addition we show hydrogen bonding network stabilization on nGLP-1R in response to ligand binding, and validate direct binding events with the extracellular domain of the receptor for putative GLP-1R small molecule ligands.

Chemistry in Teaching The Moral of the Phlogiston Theory

Directory of Open Access Journals (Sweden)

N. Raos

2015-05-01

Full Text Available The phlogiston theory, proposed in 1697 by German physician Georg Ernst Stahl (1659 – 1734, was the first scientific theory of combustion. However, it was abandoned by the end of the 18th century after the “Lavoisier revolution”, primarily because it was unable to explain the mass change during chemical reactions. In spite of this, there are modern revitalizations of the theory, claiming that phlogiston could be identified with the electron or even with Gibbs energy. Discussion about such interpretations would be stimulative for the better understanding of the differences between chemical reactions and chemical processes, oxidation and oxygenation, and especially for better understanding the nature of scientific theories. In my view, it is necessary to regard theories in their historical context; the resemblance of an old theory to a new one cannot be the criterion of its validity, much more important is the influence of the former theory on the development of science, especially in the establishment of new concepts.

Range of validity of transport equations

International Nuclear Information System (INIS)

Berges, Juergen; Borsanyi, Szabolcs

2006-01-01

Transport equations can be derived from quantum field theory assuming a loss of information about the details of the initial state and a gradient expansion. While the latter can be systematically improved, the assumption about a memory loss is not known to be controlled by a small expansion parameter. We determine the range of validity of transport equations for the example of a scalar g 2 Φ 4 theory. We solve the nonequilibrium time evolution using the three-loop 2PI effective action. The approximation includes off-shell and memory effects and assumes no gradient expansion. This is compared to transport equations to lowest order (LO) and beyond (NLO). We find that the earliest time for the validity of transport equations is set by the characteristic relaxation time scale t damp =-2ω/Σ ρ (eq) , where -Σ ρ (eq) /2 denotes the on-shell imaginary-part of the self-energy. This time scale agrees with the characteristic time for partial memory loss, but is much shorter than thermal equilibration times. For times larger than about t damp the gradient expansion to NLO is found to describe the full results rather well for g 2 (less-or-similar sign)1

Chiral gauge theory on AdS domain wall

International Nuclear Information System (INIS)

Shirman, Yuri

2005-01-01

We describe a realization of chiral gauge theories based on the domaim wall fermion construction implemented on an interval in five dimensional AdS spacetime. At semi-classical level deconstructed description of the theory is given in terms of 4-dimensional Minkowski slices supporting chiral zero modes at the ends. Energy scales warp down along the fifth dimension. When the theory is augmented by 4-dimensional neutral Majorana spinors together with the Higgs mechanism at the low energy end, we can arrange for a theory where the lightest gauge boson mode as well as chiral zero mode at the high energy end are parametrically lighter than other states. Triangle anomalies and instanton effects are expected to make gauge bosons heavy if the resulting effective theory is anomalous. Due to the strong coupling effects at the quantum level, full non-perturbative calculation will be necessary to validate this construction

Dengeleme Teorisi’nin Geçerliliğinin Panel Veri Analizi ile Test Edilmesi: BİST’de Ampirik Bir Uygulama(Testing the Validity of Trade-Off Theory by Using Panel Regression Analysis: An Empirical Application on ISE

Directory of Open Access Journals (Sweden)

İbrahim BOZKURT

2014-12-01

Full Text Available The aim of this study is to test the validity of Trade-Off theory by investigating the relationship between capital structures and market values of firms on ISE. In this study, 127.008 financial ratio, 20.664 monthly stock return, 4.704 market value and debt ratio which are belong to 168 firms traded on ISE between 2005 and 2011 is used. Firstly, efficient model predicting bankruptcy is confirmed by using balanced panel regression analysis for ISE. Secondly, by using efficient model, firms are divided two groups that consist of firms which have or not bankruptcy risk for each period and the relationship market values and debt levels of firms in each group is analyzed by using unbalanced panel regression analysis. The results of the analysis reveal that there is positive relationship between market values and debt levels of firms in terms of both groups. This result implies that Trade-Off theory is not validity on ISE.

Victories and defeats in general relativity theory

International Nuclear Information System (INIS)

Moeller, C.

1977-01-01

Only within the last 20 years has it been possible to conduct far-reaching experimental tests of the validity of Einstein's General Relativity Theory. Experimental confirmation in some fields is embarrassed by considerable difficulties in applying the theory to cosmic systems, which indicate that such major systems lie at the limit of the theory's applicability. The lecture here reproduced discusses both the successes and the limitations of the theory, starting with its replacement of the absolute space-time theory of Newton and its historical replacement by the relativistic gravitational postulates of Einstein which, in spite of its more complicated postulates, nevertheless introduced a great simplicity and comprehensiveness into the overall conception of nature. This theoretical 'beauty', however, can only be trusted if vindicated experimentally, which has to a considerable extent proved to be the case. For weak fields Newtonian and Einsteinian concepts coincide, while for stronger fields, and velocities not far from that of light, Einstein's theory is superior, giving,for example, an excellent correspondence with the precession of the perehelion of Mercury. On a larger scale, however, the theory appears to lead to conclusions which would invalidate the very concepts of space and time, even within a finite time-interval. A more generalized theory seems to be required. (A.D.N.)

Fermion boson metamorphosis in field theory

International Nuclear Information System (INIS)

Ha, Y.K.

1982-01-01

In two-dimensional field theories many features are especially transparent if the Fermi fields are represented by non-local expressions of the Bose fields. Such a procedure is known as boson representation. Bilinear quantities appear in the Lagrangian of a fermion theory transform, however, as simple local expressions of the bosons so that the resulting theory may be written as a theory of bosons. Conversely, a theory of bosons may be transformed into an equivalent theory of fermions. Together they provide a basis for generating many interesting equivalences between theories of different types. In the present work a consistent scheme for constructing a canonical Fermi field in terms of a real scalar field is developed and such a procedure is valid and consistent with the tenets of quantum field theory is verified. A boson formulation offers a unifying theme in understanding the structure of many theories. This is illustrated by the boson formulation of a multifermion theory with chiral and internal symmetries. The nature of dynamical generation of mass when the theory undergoes boson transmutation and the preservation of continuous chiral symmetry in the massive case are examined. The dynamics of the system depends to a great extent on the specific number of fermions and different models of the same system can have very different properties. Many unusual symmetries of the fermion theory, such as hidden symmetry, duality and triality symmetries, are only manifest in the boson formulation. The underlying connections between some models with U(N) internal symmetry and another class of fermion models built with Majorana fermions which have O(2N) internal symmetry are uncovered

The LDL receptor.

Science.gov (United States)

Goldstein, Joseph L; Brown, Michael S

2009-04-01

In this article, the history of the LDL receptor is recounted by its codiscoverers. Their early work on the LDL receptor explained a genetic cause of heart attacks and led to new ways of thinking about cholesterol metabolism. The LDL receptor discovery also introduced three general concepts to cell biology: receptor-mediated endocytosis, receptor recycling, and feedback regulation of receptors. The latter concept provides the mechanism by which statins selectively lower plasma LDL, reducing heart attacks and prolonging life.

Assessing motivation orientations in schizophrenia: Scale development and validation.

Science.gov (United States)

Cooper, Shanna; Lavaysse, Lindsey M; Gard, David E

2015-01-30

Motivation deficits are common in several disorders including schizophrenia, and are an important factor in both functioning and treatment adherence. Self-Determination Theory (SDT), a leading macro-theory of motivation, has contributed a number of insights into how motivation is impaired in schizophrenia. Nonetheless, self-report measures of motivation appropriate for people with severe mental illness (including those that emphasize SDT) are generally lacking in the literature. To fill this gap, we adapted and abbreviated the well-validated General Causality Orientation Scale for use with people with schizophrenia and with other severe mental disorders (GCOS-clinical populations; GCOS-CP). In Study 1, we tested the similarity of our measure to the existing GCOS (using a college sample) and then validated this new measure in a schizophrenia and healthy control sample (Study 2). Results from Study 1 (N=360) indicated that the GCOS-CP was psychometrically similar to the original GCOS and provided good convergent and discriminant validity. In Study 2, the GCOS-CP was given to individuals with (N=44) and without schizophrenia (N=42). In line with both laboratory-based and observer-based research, people with schizophrenia showed lower motivational autonomy and higher impersonal/amotivated orientations. Additional applications of the GCOS-CP are discussed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Errors in the universal and sufficient heuristic criteria of estimating validity limits of geometric optics and of the geometric theory of diffraction

International Nuclear Information System (INIS)

Borovikov, V.A.; Kinber, B.E.

1988-01-01

The heuristic criteria (HC) of validity of geometric optics (GO) and of the geometric theory of diffraction (GTD), suggested in [2-7, 13, 14] and based on identifying the physical volume occupied by the ray with the Fresnel volume (FV) introduced in these papers (i.e., the envelope of the first Fresnel zone), are analyzed. Numerous examples of HC invalidity are given, as well as the reasons. In particular, HC provide an incorrect answer for all GO problems with caustics, since in these problems there always exists a ray, whose FV is nonlocal and covers the FV of other rays. The HC are shown to be unsuitable for multiple ray GTD problems, as well as for the simplest problems of diffraction of a cylindrical wave by a half-plane and of a plane wave by a curved half-plane

The Theory of EU Constitutional Pluralism: A Crisis in a Crisis?

Directory of Open Access Journals (Sweden)

Pierdominici Leonardo

2017-11-01

Full Text Available The paper deals with the validity of constitutional pluralism as a constitutional theory for the European Union and a paradigm for the understanding of EU law in the current times of crisis. It reconstructs the way in which constitutional pluralism came to the fore, the different ways in which the theory was presented, and considers historical criticism it has faced. It then looks at the anomalies that, allegedly, cannot be explained today by constitutional pluralism as a paradigm, linked to the current economic and political crises in the Union. The reconstruction of the debate is complemented with reflections on both the descriptive and normative validity of EU constitutional pluralism’s claims.

Endogenous hallucinogens as ligands of the trace amine receptors: a possible role in sensory perception.

Science.gov (United States)

Wallach, J V

2009-01-01

While the endogenous hallucinogens, N,N-dimethyltryptamine, 5-hydroxy-N,N-dimethyl-tryptamine and 5-methoxy-N,N-dimethyltryptamine, have been acknowledged as naturally occurring components of the mammalian body for decades, their biological function remains as elusive now as it was at the time of their discovery. The recent discovery of the trace amine associated receptors and the activity of DMT and other hallucinogenic compounds at these receptor sites leads to the hypothesis that the endogenous hallucinogens act as neurotransmitters of a subclass of these trace amine receptors. Additionally, while activity at the serotonin 5-HT2A receptor has been proposed as being responsible for the hallucinogenic affects of administered hallucinogens, in their natural setting the 5-HT2A receptor may not interact with the endogenous hallucinogens at all. Additionally 5-HT2A agonist activity is unable to account for the visual altering effects of many of the administered hallucinogens; these effects may be mediated by one of the endogenous hallucinogen trace amine receptors rather than the serotonin 5-HT2A receptor. Therefore, activity at the trace amine receptors, in addition to serotonin receptors, may play a large role in the sensory altering effects of administered hallucinogens and the trace amine receptors along with their endogenous hallucinogen ligands may serve an endogenous role in mediating sensory perception in the mammalian central nervous system. Thus the theory proposed states that these compounds act as true endogenous hallucinogenic transmitters acting in regions of the central nervous system involved in sensory perception.

Adenosine A{sub 2A} receptor imaging with [{sup 11}C]KF18446 PET in the rat brain after quinolinic acid lesion. Comparison with the dopamine receptor imaging

Energy Technology Data Exchange (ETDEWEB)

Ishiwata, Kiichi; Ogi, Nobuo; Hayakawa, Nobutaka [Tokyo Metropolitan Inst. of Gerontology, Tokyo (Japan). Positron Medical Center] [and others

2002-11-01

We proposed [{sup 11}C]KF18446 as a selective radioligand for mapping the adenosine A{sub 2A} receptors being highly enriched in the striatum by positron emission tomography (PET). In the present study, we investigated whether [{sup 11}C]KF18446 PET can detect the change in the striatal adenosine A{sub 2A} receptors in the rat after unilateral injection of an excitotoxin quinolinic acid into the striatum, a Huntington's disease model, to demonstrate the usefulness of [{sup 11}C]KF18446. The extent of the striatal lesion was identified based on MRI, to which the PET was co-registered. The binding potential of [{sup 11}C]KF18446 significantly decreased in the quinolinic acid-lesioned striatum. The decrease was comparable to the decrease in the potential of [{sup 11}C] raclopride binding to dopamine D{sub 2} receptors in the lesioned striatum, but seemed to be larger than the decrease in the potential of [{sup 11}C]SCH23390 binding to dopamine D{sub 1} receptors. Ex vivo and in vitro autoradiography validated the PET signals. We concluded that [{sup 11}C]KF18446 PET can detect change in the adenosine A{sub 2A} receptors in the rat model, and will provide a new diagnostic tool for characterizing post-synaptic striatopallidal neurons in the stratum. (author)

A new crystal structure fragment-based pharmacophore method for G protein-coupled receptors

DEFF Research Database (Denmark)

Fidom, Kimberley; Isberg, Vignir; Hauser, Alexander Sebastian

2015-01-01

and receptor residue pairs, from crystal structure complexes. We describe the procedure to collect a library with more than 250 fragments covering 29 residue positions within the generic transmembrane binding pocket. We describe how the library fragments are recombined and inferred to build pharmacophores...... for new targets. A validating retrospective virtual screening of histamine H1 and H3 receptor pharmacophores yielded area-under-the-curves of 0.88 and 0.82, respectively. The fragment-based method has the unique advantage that it can be applied to targets for which no (homologous) crystal structures...... or ligands are known. 47% of the class A G protein-coupled receptors can be targeted with at least four-element pharmacophores. The fragment libraries can also be used to grow known ligands or for rotamer refinement of homology models. Researchers can download the complete fragment library or a subset...

Development and validation of a theoretical test in basic laparoscopy

DEFF Research Database (Denmark)

Strandbygaard, Jeanett; Maagaard, Mathilde; Larsen, Christian Rifbjerg

2013-01-01

for first-year residents in obstetrics and gynecology. This study therefore aimed to develop and validate a framework for a theoretical knowledge test, a multiple-choice test, in basic theory related to laparoscopy. METHODS: The content of the multiple-choice test was determined by conducting informal...... conversational interviews with experts in laparoscopy. The subsequent relevance of the test questions was evaluated using the Delphi method involving regional chief physicians. Construct validity was tested by comparing test results from three groups with expected different clinical competence and knowledge.......001). Internal consistency (Cronbach's alpha) was 0.82. There was no evidence of differential item functioning between the three groups tested. CONCLUSIONS: A newly developed knowledge test in basic laparoscopy proved to have content and construct validity. The formula for the development and validation...

A numerical assessment of rough surface scattering theories. I - Horizontal polarization. II - Vertical polarization

Science.gov (United States)

Rodriguez, Ernesto; Kim, Yunjin; Durden, Stephen L.

1992-01-01

A numerical evaluation is presented of the regime of validity for various rough surface scattering theories against numerical results obtained by employing the method of moments. The contribution of each theory is considered up to second order in the perturbation expansion for the surface current. Considering both vertical and horizontal polarizations, the unified perturbation method provides best results among all theories weighed.

Development of a nonlinear unsteady transonic flow theory

Science.gov (United States)

Stahara, S. S.; Spreiter, J. R.

1973-01-01

A nonlinear, unsteady, small-disturbance theory capable of predicting inviscid transonic flows about aerodynamic configurations undergoing both rigid body and elastic oscillations was developed. The theory is based on the concept of dividing the flow into steady and unsteady components and then solving, by method of local linearization, the coupled differential equation for unsteady surface pressure distribution. The equations, valid at all frequencies, were derived for two-dimensional flows, numerical results, were obtained for two classses of airfoils and two types of oscillatory motions.

Effects of the potential 5-HT7 receptor agonist AS 19 in an autoshaping learning task.

Science.gov (United States)

Perez-García, Georgina S; Meneses, A

2005-08-30

This work aimed to evaluate further the role of 5-HT7 receptors during memory formation in an autoshaping Pavlovian/instrumental learning task. Post-training administration of the potential 5-HT7 receptor agonist AS 19 or antagonist SB-269970 enhanced memory formation or had no effect, respectively. The AS 19 facilitatory effect was reversed by SB-269970, but not by the selective 5-HT1A antagonist WAY100635. Amnesia induced by scopolamine (cholinergic antagonist) or dizocilpine (NMDA antagonist) was also reversed by AS 19. Certainly, reservations regarding the selectivity of AS 19 for 5-HT7 and other 5-HT receptors in vivo are noteworthy and, therefore, its validity for use in animal models as a pharmacological tool. Having mentioned that, it should be noticed that together these data are providing further support to the notion of the 5-HT7 receptors role in memory formation. Importantly, this 5-HT7 receptor agonist AS 19 appears to represent a step forward respect to the notion that potent and selective 5-HT7 receptor agonists can be useful in the treatment of dysfunctional memory in aged-related decline and Alzheimer's disease.

Supersymmetry restoration in superstring perturbation theory

International Nuclear Information System (INIS)

Sen, Ashoke

2015-01-01

Superstring perturbation theory based on the 1PI effective theory approach has been useful for addressing the problem of mass renormalization and vacuum shift. We derive Ward identities associated with space-time supersymmetry transformation in this approach. This leads to a proof of the equality of renormalized masses of bosons and fermions and identities relating fermionic amplitudes to bosonic amplitudes after taking into account the effect of mass renormalization. This also relates unbroken supersymmetry to a given order in perturbation theory to absence of tadpoles of massless scalars to higher order. The results are valid at the perturbative vacuum as well as in the shifted vacuum when the latter describes the correct ground state of the theory. We apply this to SO(32) heterotic string theory on Calabi-Yau 3-folds where a one loop Fayet-Iliopoulos term apparently breaks supersymmetry at one loop, but analysis of the low energy effective field theory indicates that there is a nearby vacuum where supersymmetry is restored. We explicitly prove that the perturbative amplitudes of this theory around the shifted vacuum indeed satisfy the Ward identities associated with unbroken supersymmetry. We also test the general arguments by explicitly verifying the equality of bosonic and fermionic masses at one loop order in the shifted vacuum, and the appearance of two loop dilaton tadpole in the perturbative vacuum where supersymmetry is expected to be broken.

Supersymmetry restoration in superstring perturbation theory

Energy Technology Data Exchange (ETDEWEB)

Sen, Ashoke [Harish-Chandra Research Institute,Chhatnag Road, Jhusi, Allahabad 211019 (India)

2015-12-14

Superstring perturbation theory based on the 1PI effective theory approach has been useful for addressing the problem of mass renormalization and vacuum shift. We derive Ward identities associated with space-time supersymmetry transformation in this approach. This leads to a proof of the equality of renormalized masses of bosons and fermions and identities relating fermionic amplitudes to bosonic amplitudes after taking into account the effect of mass renormalization. This also relates unbroken supersymmetry to a given order in perturbation theory to absence of tadpoles of massless scalars to higher order. The results are valid at the perturbative vacuum as well as in the shifted vacuum when the latter describes the correct ground state of the theory. We apply this to SO(32) heterotic string theory on Calabi-Yau 3-folds where a one loop Fayet-Iliopoulos term apparently breaks supersymmetry at one loop, but analysis of the low energy effective field theory indicates that there is a nearby vacuum where supersymmetry is restored. We explicitly prove that the perturbative amplitudes of this theory around the shifted vacuum indeed satisfy the Ward identities associated with unbroken supersymmetry. We also test the general arguments by explicitly verifying the equality of bosonic and fermionic masses at one loop order in the shifted vacuum, and the appearance of two loop dilaton tadpole in the perturbative vacuum where supersymmetry is expected to be broken.

Simple recursion relations for general field theories

International Nuclear Information System (INIS)

Cheung, Clifford; Shen, Chia-Hsien; Trnka, Jaroslav

2015-01-01

On-shell methods offer an alternative definition of quantum field theory at tree-level, replacing Feynman diagrams with recursion relations and interaction vertices with a handful of seed scattering amplitudes. In this paper we determine the simplest recursion relations needed to construct a general four-dimensional quantum field theory of massless particles. For this purpose we define a covering space of recursion relations which naturally generalizes all existing constructions, including those of BCFW and Risager. The validity of each recursion relation hinges on the large momentum behavior of an n-point scattering amplitude under an m-line momentum shift, which we determine solely from dimensional analysis, Lorentz invariance, and locality. We show that all amplitudes in a renormalizable theory are 5-line constructible. Amplitudes are 3-line constructible if an external particle carries spin or if the scalars in the theory carry equal charge under a global or gauge symmetry. Remarkably, this implies the 3-line constructibility of all gauge theories with fermions and complex scalars in arbitrary representations, all supersymmetric theories, and the standard model. Moreover, all amplitudes in non-renormalizable theories without derivative interactions are constructible; with derivative interactions, a subset of amplitudes is constructible. We illustrate our results with examples from both renormalizable and non-renormalizable theories. Our study demonstrates both the power and limitations of recursion relations as a self-contained formulation of quantum field theory.

A Novel Bioinspired PVDF Micro/Nano Hair Receptor for a Robot Sensing System

Directory of Open Access Journals (Sweden)

Xin Fu

2010-01-01

Full Text Available This paper describes the concept and design of a novel artificial hair receptor for the sensing system of micro intelligent robots such as a cricket-like jumping mini robot. The concept is inspired from the natural hair receptor of animals, also called cilium or filiform hair by different research groups, which is usually used as a vibration receptor or a flow detector by insects, mammals and fishes. The suspended fiber model is firstly built and the influence of scaling down is analyzed theoretically. The design of this artificial hair receptor is based on aligned suspended PVDF (polyvinylidene fluoride fibers, manufactures with a novel method called thermo-direct drawing technique, and aligned suspended submicron diameter fibers are thus successfully fabricated on a flexible Kapton. In the post process step, some key problems such as separated electrodes deposition along with the fiber drawing direction and poling of micro/nano fibers to impart them with good piezoeffective activity have been presented. The preliminary validation experiments show that the artificial hair receptor has a reliable response with good sensibility to external pressure variation and, medium flow as well as its prospects in the application on sensing system of mini/micro bio-robots.

Comparing theories' performance in predicting violence.

Science.gov (United States)

Haas, Henriette; Cusson, Maurice

2015-01-01

The stakes of choosing the best theory as a basis for violence prevention and offender rehabilitation are high. However, no single theory of violence has ever been universally accepted by a majority of established researchers. Psychiatry, psychology and sociology are each subdivided into different schools relying upon different premises. All theories can produce empirical evidence for their validity, some of them stating the opposite of each other. Calculating different models with multivariate logistic regression on a dataset of N = 21,312 observations and ninety-two influences allowed a direct comparison of the performance of operationalizations of some of the most important schools. The psychopathology model ranked as the best model in terms of predicting violence right after the comprehensive interdisciplinary model. Next came the rational choice and lifestyle model and third the differential association and learning theory model. Other models namely the control theory model, the childhood-trauma model and the social conflict and reaction model turned out to have low sensitivities for predicting violence. Nevertheless, all models produced acceptable results in predictions of a non-violent outcome. Copyright © 2015. Published by Elsevier Ltd.

Fundamental Flaws In The Derivation Of Stevens' Law For Taste Within Norwich's Entropy Theory of Perception

International Nuclear Information System (INIS)

Nizami, Lance

2010-01-01

Norwich's Entropy Theory of Perception (1975-present) is a general theory of perception, based on Shannon's Information Theory. Among many bold claims, the Entropy Theory presents a truly astounding result: that Stevens' Law with an Index of 1, an empirical power relation of direct proportionality between perceived taste intensity and stimulus concentration, arises from theory alone. Norwich's theorizing starts with several extraordinary hypotheses. First, 'multiple, parallel receptor-neuron units' without collaterals 'carry essentially the same message to the brain', i.e. the rate-level curves are identical. Second, sensation is proportional to firing rate. Third, firing rate is proportional to the taste receptor's 'resolvable uncertainty'. Fourth, the 'resolvable uncertainty' is obtained from Shannon's Information Theory. Finally, 'resolvable uncertainty' also depends upon the microscopic thermodynamic density fluctuation of the tasted solute. Norwich proves that density fluctuation is density variance, which is proportional to solute concentration, all based on the theory of fluctuations in fluid composition from Tolman's classic physics text, 'The Principles of Statistical Mechanics'. Altogether, according to Norwich, perceived taste intensity is theoretically proportional to solute concentration. Such a universal rule for taste, one that is independent of solute identity, personal physiological differences, and psychophysical task, is truly remarkable and is well-deserving of scrutiny. Norwich's crucial step was the derivation of density variance. That step was meticulously reconstructed here. It transpires that the appropriate fluctuation is Tolman's mean-square fractional density fluctuation, not density variance as used by Norwich. Tolman's algebra yields a 'Stevens Index' of -1 rather than 1. As 'Stevens Index' empirically always exceeds zero, the Index of -1 suggests that it is risky to infer psychophysical laws of sensory response from information theory

What Is True Halving in the Payoff Matrix of Game Theory?

Directory of Open Access Journals (Sweden)

Hiromu Ito

Full Text Available In game theory, there are two social interpretations of rewards (payoffs for decision-making strategies: (1 the interpretation based on the utility criterion derived from expected utility theory and (2 the interpretation based on the quantitative criterion (amount of gain derived from validity in the empirical context. A dynamic decision theory has recently been developed in which dynamic utility is a conditional (state variable that is a function of the current wealth of a decision maker. We applied dynamic utility to the equal division in dove-dove contests in the hawk-dove game. Our results indicate that under the utility criterion, the half-share of utility becomes proportional to a player's current wealth. Our results are consistent with studies of the sense of fairness in animals, which indicate that the quantitative criterion has greater validity than the utility criterion. We also find that traditional analyses of repeated games must be reevaluated.

What Is True Halving in the Payoff Matrix of Game Theory?

Science.gov (United States)

Hasegawa, Eisuke; Yoshimura, Jin

2016-01-01

In game theory, there are two social interpretations of rewards (payoffs) for decision-making strategies: (1) the interpretation based on the utility criterion derived from expected utility theory and (2) the interpretation based on the quantitative criterion (amount of gain) derived from validity in the empirical context. A dynamic decision theory has recently been developed in which dynamic utility is a conditional (state) variable that is a function of the current wealth of a decision maker. We applied dynamic utility to the equal division in dove-dove contests in the hawk-dove game. Our results indicate that under the utility criterion, the half-share of utility becomes proportional to a player’s current wealth. Our results are consistent with studies of the sense of fairness in animals, which indicate that the quantitative criterion has greater validity than the utility criterion. We also find that traditional analyses of repeated games must be reevaluated. PMID:27487194

Nonperturbative loop quantization of scalar-tensor theories of gravity

International Nuclear Information System (INIS)

Zhang Xiangdong; Ma Yongge

2011-01-01

The Hamiltonian formulation of scalar-tensor theories of gravity is derived from their Lagrangian formulation by Hamiltonian analysis. The Hamiltonian formalism marks off two sectors of the theories by the coupling parameter ω(φ). In the sector of ω(φ)=-(3/2), the feasible theories are restricted and a new primary constraint generating conformal transformations of spacetime is obtained, while in the other sector of ω(φ)≠-(3/2), the canonical structure and constraint algebra of the theories are similar to those of general relativity coupled with a scalar field. By canonical transformations, we further obtain the connection-dynamical formalism of the scalar-tensor theories with real su(2) connections as configuration variables in both sectors. This formalism enables us to extend the scheme of nonperturbative loop quantum gravity to the scalar-tensor theories. The quantum kinematical framework for the scalar-tensor theories is rigorously constructed. Both the Hamiltonian constraint operator and master constraint operator are well defined and proposed to represent quantum dynamics. Thus the loop quantum gravity method is also valid for general scalar-tensor theories.

Dopamine Receptor D4 Gene Variation Predicts Preschoolers' Developing Theory of Mind

Science.gov (United States)

Lackner, Christine; Sabbagh, Mark A.; Hallinan, Elizabeth; Liu, Xudong; Holden, Jeanette J. A.

2012-01-01

Individual differences in preschoolers' understanding that human action is caused by internal mental states, or representational theory of mind (RTM), are heritable, as are developmental disorders such as autism in which RTM is particularly impaired. We investigated whether polymorphisms of genes affecting dopamine (DA) utilization and metabolism…

β-Adrenergic receptor-mediated suppression of interleukin 2 receptors in human lymphocytes

International Nuclear Information System (INIS)

Feldman, R.D.; Hunninghake, G.W.; McArdle, W.L.

1987-01-01

Adrenergic receptor agonists are know to attenuate the proliferative response of human lymphocytes after activation; however, their mechanism of action is unknown. Since expression of interleukin 2 (IL-2) receptors is a prerequisite for proliferation, the effect of β-adrenergic receptor agonists on lymphocyte IL-2 receptors was studied on both mitogen-stimulated lymphocytes and IL-2-dependent T lymphocyte cell lines. In both cell types the β-adrenergic receptor agonist isoproterenol blocked the expression of IL-2 receptors, as determined with the IL-2 receptor anti-TAC antibody. To determine the effect of β-adrenergic agonists on expression of the high affinity IL-2 receptors, [ 125 I]IL-2 binding studies were performed at concentrations selective for high affinity sites. No significant effect of β-adrenergic agonists on high affinity IL-2 receptor sites could be detected. The data demonstrate that β-adrenergic receptor agonists down-regulate IL-2 receptors primarily affecting low affinity sites

Structure-activity relationships for serotonin transporter and dopamine receptor selectivity.

Science.gov (United States)

Agatonovic-Kustrin, Snezana; Davies, Paul; Turner, Joseph V

2009-05-01

Antipsychotic medications have a diverse pharmacology with affinity for serotonergic, dopaminergic, adrenergic, histaminergic and cholinergic receptors. Their clinical use now also includes the treatment of mood disorders, thought to be mediated by serotonergic receptor activity. The aim of our study was to characterise the molecular properties of antipsychotic agents, and to develop a model that would indicate molecular specificity for the dopamine (D(2)) receptor and the serotonin (5-HT) transporter. Back-propagation artificial neural networks (ANNs) were trained on a dataset of 47 ligands categorically assigned antidepressant or antipsychotic utility. The structure of each compound was encoded with 63 calculated molecular descriptors. ANN parameters including hidden neurons and input descriptors were optimised based on sensitivity analyses, with optimum models containing between four and 14 descriptors. Predicted binding preferences were in excellent agreement with clinical antipsychotic or antidepressant utility. Validated models were further tested by use of an external prediction set of five drugs with unknown mechanism of action. The SAR models developed revealed the importance of simple molecular characteristics for differential binding to the D(2) receptor and the 5-HT transporter. These included molecular size and shape, solubility parameters, hydrogen donating potential, electrostatic parameters, stereochemistry and presence of nitrogen. The developed models and techniques employed are expected to be useful in the rational design of future therapeutic agents.

Designing and determining validity and reliability of a questionnaire to identify factors affecting nutritional behavior among patients with metabolic syndrome

Directory of Open Access Journals (Sweden)

Naseh Esmaeili

2017-06-01

Full Text Available Background : A number of studies have shown a clear relationship between diet and component of metabolic syndrome. Based on the Theory of Reasoned Action (TRA, attitude and subjective norm are factors affecting behavioral intention and subsequently behavior. The aim of the present study is to design a valid questionnaire identifying factors affecting nutritional behavior among patients with metabolic syndrome. Materials and Methods: Via literature review, six focus group discussion and interview with nutrition specialists were performed to develop an instrument based on the theory of reasoned action. To determine validity of the instrument, content and face validity analyses with 15 expert panels conducted and also to determine reliability, Cronbach’s Alpha coefficient performed. Results: A draft of 100 items questionnaire was developed and after evaluation of validity and reliability, final questionnaire included 46 items: 17 items for attitude, 13 items for subjective norms and 16 items for behavioral intention. For the final questionnaire average of content validity index was 0/92 and Cronbach’s Alpha coefficient was 0/85. Conclusion: Based on the results of the current study the developed questionnaire is a valid and reliable instrument and it can be used to identify factors affecting nutritional behavior among people with metabolic syndrome based on the theory of reasoned action.

Factorial validity of the Problematic Facebook Use Scale for adolescents and young adults.

Science.gov (United States)

Marino, Claudia; Vieno, Alessio; Altoè, Gianmarco; Spada, Marcantonio M

2017-03-01

Background and aims Recent research on problematic Facebook use has highlighted the need to develop a specific theory-driven measure to assess this potential behavioral addiction. The aim of the present study was to examine the factorial validity of the Problematic Facebook Use Scale (PFUS) adapted from Caplan's Generalized Problematic Internet Scale model. Methods A total of 1,460 Italian adolescents and young adults (aged 14-29 years) participated in the study. Confirmatory factor analyses were performed in order to assess the factorial validity of the scale. Results Results revealed that the factor structure of the PFUS provided a good fit to the data. Furthermore, results of the multiple group analyses supported the invariance of the model across age and gender groups. Discussion and conclusions This study provides evidence supporting the factorial validity of the PFUS. This new scale provides a theory-driven tool to assess problematic use of Facebook among male and female adolescents and young adults.

Quantitative receptor radioautography in the study of receptor-receptor interactions in the nucleus tractus solitarii

Directory of Open Access Journals (Sweden)

Fior-Chadi D.R.

1998-01-01

Full Text Available The nucleus tractus solitarii (NTS in the dorsomedial medulla comprises a wide range of neuropeptides and biogenic amines. Several of them are related to mechanisms of central blood pressure control. Angiotensin II (Ang II, neuropeptide Y (NPY and noradrenaline (NA are found in the NTS cells, as well as their receptors. Based on this observation we have evaluated the modulatory effect of these peptide receptors on a2-adrenoceptors in the NTS. Using quantitative receptor radioautography, we observed that NPY and Ang II receptors decreased the affinity of a2-adrenoceptors for their agonists in the NTS of the rat. Cardiovascular experiments agreed with the in vitro data. Coinjection of a threshold dose of Ang II or of the NPY agonists together with an ED50 dose of adrenergic agonists such as NA, adrenaline and clonidine counteracted the depressor effect produced by the a2-agonist in the NTS. The results provide evidence for the existence of an antagonistic interaction between Ang II at1 receptors and NPY receptor subtypes with the a2-adrenoceptors in the NTS. This receptor interaction may reduce the transduction over the a2-adrenoceptors which can be important in central cardiovascular regulation and in the development of hypertension

Innovation, Product Development, and New Business Models in Networks: How to come from case studies to a valid and operational theory

DEFF Research Database (Denmark)

Rasmussen, Erik Stavnsager; Jørgensen, Jacob Høj; Goduscheit, René Chester

2007-01-01

We have in the research project NEWGIBM (New Global ICT based Business Models) during 2005 and 2006 closely cooperated with a group of firms. The focus in the project has been development of new business models (and innovation) in close cooperation with multiple partners. These partners have been...... customers, suppliers, R&D partners, and others. The methodological problem is thus, how to come from e.g. one in-depth case study to a more formalized theory or model on how firms can develop new projects and be innovative in a network. The paper is structured so that it starts with a short presentation...... of the two key concepts in our research setting and theoretical models: Innovation and networks. It is not our intention in this paper to present a lengthy discussion of the two concepts, but a short presentation is necessary to understand the validity and interpretation discussion later in the paper. Next...

76 FR 28781 - Independent Scientific Peer Review Panel Report: Evaluation of the Validation Status of an In...

Science.gov (United States)

2011-05-18

... Scientific Advisory Committee on Alternative Toxicological Methods (SACATM) recommended that the BG1Luc ER TA... DEPARTMENT OF HEALTH AND HUMAN SERVICES Independent Scientific Peer Review Panel Report: Evaluation of the Validation Status of an In Vitro Estrogen Receptor Transcriptional Activation Test Method...

Development and validation of a game addiction scale for adolescents

NARCIS (Netherlands)

Lemmens, J.S.; Valkenburg, P.M.; Peter, J.

2009-01-01

The aim of this study was to develop and validate a scale to measure computer and videogame addiction. Inspired by earlier theories and research on game addiction, we created 21 items to measure seven underlying criteria (i.e., salience, tolerance, mood modification, relapse, withdrawal, conflict,

Perturbation theory with instantons

International Nuclear Information System (INIS)

Carruthers, P.; Pinsky, S.S.; Zachariasen, F.

1977-05-01

''Perturbation theory'' rules are developed for calculating the effect of instantons in a pure Yang-Mills theory with no fermions, in the ''dilute gas'' approximation in which the N-instanton solution is assumed to be the sum of N widely separated one-instanton solutions. These rules are then used to compute the gluon propagator and proper vertex function including all orders of the instanton interaction but only to lowest order in the gluon coupling. It is to be expected that such an approximation is valid only for momenta q larger than the physical mass μ. The result is that in this regime instantons cause variations in the propagator and vertex of the form (μ 2 /q 2 )/sup -8π 2 b/ where b is the coefficient in the expansion of the β function: β = bg 3 +...

Serotonin receptor activity is necessary for olfactory learning and memory in Drosophila melanogaster.

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Johnson, O; Becnel, J; Nichols, C D

2011-09-29

Learning and memory in the fruit fly, Drosophila melanogaster, is a complex behavior with many parallels to mammalian learning and memory. Although many neurotransmitters including acetylcholine, dopamine, glutamate, and GABA have previously been demonstrated to be involved in aversive olfactory learning and memory, the role of serotonin has not been well defined. Here, we present the first evidence of the involvement of individual serotonin receptors in olfactory learning and memory in the fly. We initially followed a pharmacological approach, utilizing serotonin receptor agonists and antagonists to demonstrate that all serotonin receptor families present in the fly are necessary for short-term learning and memory. Isobolographic analysis utilizing combinations of drugs revealed functional interactions are occurring between 5-HT(1A)-like and 5-HT(2), and 5-HT(2) and 5-HT(7) receptor circuits in mediating short-term learning and memory. Examination of long-term memory suggests that 5-HT(1A)-like receptors are necessary for consolidation and important for recall, 5-HT(2) receptors are important for consolidation and recall, and 5-HT(7) receptors are involved in all three phases. Importantly, we have validated our pharmacological results with genetic experiments and showed that hypomorph strains for 5-HT(2)Dro and 5-HT(1B)Dro receptors, as well as knockdown of 5-HT(7)Dro mRNA, significantly impair performance in short-term memory. Our data highlight the importance of the serotonin system and individual serotonin receptors to influence olfactory learning and memory in the fly, and position the fly as a model system to study the role of serotonin in cognitive processes relevant to mammalian CNS function. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Radiosynthesis and in vitro validation of 3H-NS14492 as a novel high affinity alpha7 nicotinic receptor radioligand

DEFF Research Database (Denmark)