Barbuto, John E; Moss, Jennifer A
2006-08-01
The relations of intrinsic and extrinsic motivation with use of consultative, legitimating, and pressure influence tactics were examined using validity generalization procedures. 5 to 7 field studies with cumulative samples exceeding 800 were used to test each relationship. Significance was found for relation between agents' intrinsic motivation and their use of consultative influence tactics and agents' extrinsic motivation and their use of legitimating influence tactics.
Straumann, Norbert
2013-01-01
This book provides a completely revised and expanded version of the previous classic edition ‘General Relativity and Relativistic Astrophysics’. In Part I the foundations of general relativity are thoroughly developed, while Part II is devoted to tests of general relativity and many of its applications. Binary pulsars – our best laboratories for general relativity – are studied in considerable detail. An introduction to gravitational lensing theory is included as well, so as to make the current literature on the subject accessible to readers. Considerable attention is devoted to the study of compact objects, especially to black holes. This includes a detailed derivation of the Kerr solution, Israel’s proof of his uniqueness theorem, and a derivation of the basic laws of black hole physics. Part II ends with Witten’s proof of the positive energy theorem, which is presented in detail, together with the required tools on spin structures and spinor analysis. In Part III, all of the differential geomet...
Canuto, V
2015-01-01
This is an English translation of the Italian version of an encyclopedia chapter that appeared in the Italian Encyclopedia of the Physical Sciences, edited by Bruno Bertotti (1994). Following requests from colleagues we have decided to make it available to a more general readership. We present the motivation for constructing General Relativity, provide a short discussion of tensor algebra, and follow the set up of Einstein equations. We discuss briefly the initial value problem, the linear approximation and how should non gravitational physics be described in curved spacetime.
Khriplovich, I. B
2005-01-01
This book offers an alternative to other textbooks on the subject, providing a more specific discussion of numerous general relativistic effects for readers who have knowledge of classical mechanics and electrodynamics, including special relativity. Coverage includes gravitational lensing, signal retardation in the gravitational field of the Sun, the Reissner-Nordström solution, selected spin effects, the resonance transformation of an electromagnetic wave into a gravitational one, and the entropy and temperature of black holes. The book includes numerous problems at various levels of difficulty, making it ideal also for independent study by a broad readership of advanced students and researchers. I.B. Khriplovich is Chief Researcher, Budker Institute of Nuclear Physics, Novosibirsk, and Chair of Theoretical Physics at Novosibirsk University. Dr. Khriplovich is a Corresponding Member of the Russian Academy of Sciences. He has been awarded the Dirac Medal ``For the advancement of theoretical physics'' by Univ...
Coley, Alan A.; Wiltshire, David L.
2017-05-01
General relativity is a set of physical and geometric principles, which lead to a set of (Einstein) field equations that determine the gravitational field and to the geodesic equations that describe light propagation and the motion of particles on the background. But open questions remain, including: what is the scale on which matter and geometry are dynamically coupled in the Einstein equations? Are the field equations valid on small and large scales? What is the largest scale on which matter can be coarse grained while following a geodesic of a solution to Einstein’s equations? We address these questions. If the field equations are causal evolution equations, whose average on cosmological scales is not an exact solution of the Einstein equations, then some simplifying physical principle is required to explain the statistical homogeneity of the late epoch Universe. Such a principle may have its origin in the dynamical coupling between matter and geometry at the quantum level in the early Universe. This possibility is hinted at by diverse approaches to quantum gravity which find a dynamical reduction to two effective dimensions at high energies on one hand, and by cosmological observations which are beginning to strongly restrict the class of viable inflationary phenomenologies on the other. We suggest that the foundational principles of general relativity will play a central role in reformulating the theory of spacetime structure to meet the challenges of cosmology in the 21st century.
Jones, Kelly
2014-03-04
Most public dental care services provide preventive, general dental care on a chronological, first come-first served basis. There is concern about lack of transparency, equity and timeliness in access to public dental services across Australia. Using social determinants as screening criteria is a novel approach to triage in dental care and is relatively untested in the literature. The research evaluated the discriminant and predictive validity of relative social disadvantage in prioritising access to public general dental care. A consecutive sample of 615 adults seeking general dental care was selected. The validation measure used was clinical assessment of priority. Nine indicators of relative social disadvantage (RSD) were collected: Indigenous status; intellectual disability; physical disability; wheelchair usage; dwelling conditions; serious medical condition; serious medical condition and taking regular medication; hospitalised within 12 months; and, regular medical visits. At the first dental visit, dentists rated care as a priority if treatment was required ≤6 months (PriorityTx) and otherwise non-priority (non-PriorityTx). A standardised dental examination was conducted. Sensitivity, specificity, positive and negative predictive value and area under the ROC curve analyses of 1+ of RSD in predicting clinical priority were calculated. In bivariate analyses, one or more indicators of relative social disadvantage status were significantly associated with PriorityTx (P sensitivity of 77.1%, and specificity of 53.3%, together with a positive predictive value of 81.9% and negative predictive value of 46.0%. ROC curve analysis supported one or more indicators of relative social disadvantage as a predictor of greater priority for access to general dental care (0.66). Considerable heterogeneity exists among persons seeking public general dental care in New South Wales. RSD performs as a valid predictor of priority for access to treatment and acts as valid screening
Ridgely, Charles T.
2010-01-01
Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced…
van der Linden, D.; te Nijenhuis, J.; Cremers, M.; van de Ven, C.
2011-01-01
Several papers showed that a general factor occupies the top of the hierarchical structure of personality, the so-called General Factor of Personality (GFP). The first question is whether the GFP behaves similar to the general factor of mental ability (g), in that GFP scores from different
Ridgely, Charles T.
2010-07-01
Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced by an observer in general coordinates. The general force is then applied to the local co-moving coordinate system of a uniformly accelerating observer, leading to an expression of the inertial force experienced by the observer. Next, applying the general force in Schwarzschild coordinates is shown to lead to familiar expressions of the gravitational force. As a more complex demonstration, the general force is applied to an observer in Boyer-Lindquist coordinates near a rotating, Kerr black hole. It is then shown that when the angular momentum of the black hole goes to zero, the force on the observer reduces to the force on an observer held stationary in Schwarzschild coordinates. As a final consideration, the force on an observer moving in rotating coordinates is derived. Expressing the force in terms of Christoffel symbols in rotating coordinates leads to familiar expressions of the centrifugal and Coriolis forces on the observer. It is envisioned that the techniques presented herein will be most useful to graduate level students, as well as those undergraduate students having experience with general relativity and tensor analysis.
Linden, D. van der; Nijenhuis, J. te; Bakker, A.B.
2010-01-01
Recently, it has been proposed that a General Factor of Personality (GFP) occupies the top of the hierarchical personality structure. We present a meta-analysis (K = 212, total N = 144,117) on the intercorrelations among the Big Five personality factors (Openness, Conscientiousness, Extraversion,
Lectures on general relativity
Papapetrou, Achille
1974-01-01
This book is an elaboration of lecture notes for the graduate course on General Rela tivity given by the author at Boston University in the spring semester of 1972. It is an introduction to the subject only, as the time available for the course was limited. The author of an introduction to General Relativity is faced from the beginning with the difficult task of choosing which material to include. A general criterion as sisting in this choice is provided by the didactic character of the book: Those chapters have to be included in priority, which will be most useful to the reader in enabling him to understand the methods used in General Relativity, the results obtained so far and possibly the problems still to be solved. This criterion is not sufficient to ensure a unique choice. General Relativity has developed to such a degree, that it is impossible to include in an introductory textbook of a reasonable length even a very condensed treatment of all important problems which have been discussed unt...
Elements of general relativity
Agakov, Vsevolod G.; Zel'Manov, Abram L.
The main principles of general relativity (GR) are expounded, and some of its astronomical applications are discussed. Particular emphasis is placed on mathematical methods of GR developed by Zel'manov, i.e., methods of chronometrically and kinemetrically invariant quantities, and the orthometric form of the monad formalism. The application of Zel'manov's methods to problems of relativistic cosmology are considered, and a semiinverse method for solving the Einstein gravitation equations is developed.
General Relativity and Gravitation
Ashtekar, Abhay; Berger, Beverly; Isenberg, James; MacCallum, Malcolm
2015-07-01
Part I. Einstein's Triumph: 1. 100 years of general relativity George F. R. Ellis; 2. Was Einstein right? Clifford M. Will; 3. Cosmology David Wands, Misao Sasaki, Eiichiro Komatsu, Roy Maartens and Malcolm A. H. MacCallum; 4. Relativistic astrophysics Peter Schneider, Ramesh Narayan, Jeffrey E. McClintock, Peter Mészáros and Martin J. Rees; Part II. New Window on the Universe: 5. Receiving gravitational waves Beverly K. Berger, Karsten Danzmann, Gabriela Gonzalez, Andrea Lommen, Guido Mueller, Albrecht Rüdiger and William Joseph Weber; 6. Sources of gravitational waves. Theory and observations Alessandra Buonanno and B. S. Sathyaprakash; Part III. Gravity is Geometry, After All: 7. Probing strong field gravity through numerical simulations Frans Pretorius, Matthew W. Choptuik and Luis Lehner; 8. The initial value problem of general relativity and its implications Gregory J. Galloway, Pengzi Miao and Richard Schoen; 9. Global behavior of solutions to Einstein's equations Stefanos Aretakis, James Isenberg, Vincent Moncrief and Igor Rodnianski; Part IV. Beyond Einstein: 10. Quantum fields in curved space-times Stefan Hollands and Robert M. Wald; 11. From general relativity to quantum gravity Abhay Ashtekar, Martin Reuter and Carlo Rovelli; 12. Quantum gravity via unification Henriette Elvang and Gary T. Horowitz.
Introduction to general relativity
Parthasarthy, R
2016-01-01
INTRODUCTION TO GENERAL RELATIVITY begins with a description of the geometry of curved space, explaining geodesics, parallel transport, covariant differentiation, geodesic deviation and spacetime symmetry by killing vectors. It then introduces Einstein's theory of gravitation followed by Schwarzschild solution with its relevance to Positive Mass theorem. The three tests for Einstein's gravity are explained. Other exact solutions such as Vaidya, Kerr and Reisner - Nordstrom metric are included. In the Chapter on cosmological solutions, a detailed description of Godel metric is provided. It then introduces five dimensional spacetime of Kaluza showing the unification of gravity with electromagnetism. This is extended to include non-Abelian gauge theory by invoking compact extra dimensions. Explicit expressions in this case for Christoffel connections and ricci tensor are derived and the higher dimensional gravity action is shown to compactification are given.
A Validation of the Fry Syllabication Generalizations.
Costigan, Patricia
This master's thesis examines the utility of Edward Fry's 23 syllabication generalizations. To validate these rules, two sets of one thousand words each were selected, one set containing "easy" words taken from the Word Frequency Book, the second set containing "hard" words taken randomly from the Thorndike Barnhart Advanced…
Directory of Open Access Journals (Sweden)
Torén K
2017-08-01
Full Text Available Kjell Torén,1,2 Nicola Murgia,1,2 Anna-Carin Olin,1 Jan Hedner,3 John Brandberg,4 Annika Rosengren,5 Göran Bergström51Section of Occupational and Environmental Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden; 2Section of Occupational Medicine, Respiratory Diseases and Toxicology, University of Perugia, Italy; 3Department of Medicine/Lung Medicine, Sahlgrenska Academy, University of Gothenburg, 4Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, 5Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden Background: In epidemiological studies, items about physician-diagnosed COPD are often used. There is a lack of validation and standardization of these items.Materials and methods: In a general population-based study, 1,050 subjects completed a questionnaire and performed spirometry, including forced expiratory volume in 1 second (FEV1 and forced vital capacity (FVC after inhalation of 400 µg of salbutamol. COPD was defined as the ratio of FEV1/FVC <0.7 after bronchodilation. Physician-diagnosed COPD was defined as an affirmative answer to the single item: “Have you ever had COPD diagnosed by a physician?”, physician-diagnosed COPD/emphysema as an affirmative answer to any of the two single items; “Have you ever had COPD diagnosed by a physician?” or “Have you ever been told by a physician that you have emphysema?”, physician-diagnosed chronic bronchitis as an affirmative answer to; “Have you ever been told by a physician that you have chronic bronchitis?” and physician-diagnosed COPD, emphysema or chronic bronchitis was defined as an affirmative answer to either of the three items above.Results: For the single item about physician-diagnosed COPD, the sensitivity was around 0.11 and the specificity was almost 0.99 in relation to COPD. The sensitivity of the combined items about COPD
General relativity basics and beyond
Date, Ghanashyam
2015-01-01
A Broad Perspective on the Theory of General Relativity and Its Observable Implications General Relativity: Basics and Beyond familiarizes students and beginning researchers with the basic features of the theory of general relativity as well as some of its more advanced aspects. Employing the pedagogical style of a textbook, it includes essential ideas and just enough background material needed for readers to appreciate the issues and current research. Basics The first five chapters form the core of an introductory course on general relativity. The author traces Einstein’s arguments and presents examples of space-times corresponding to different types of gravitational fields. He discusses the adaptation of dynamics in a Riemannian geometry framework, the Einstein equation and its elementary properties, and different phenomena predicted or influenced by general relativity. Beyond Moving on to more sophisticated features of general relativity, the book presents the physical requirements of a well-defined de...
Generalizations of Heisenberg uncertainty relation
Energy Technology Data Exchange (ETDEWEB)
Trifonov, D.A. [Institute for Nuclear Research, Sofia (Bulgaria)
2002-09-01
A survey on the generalizations of Heisenberg uncertainty relation and a general scheme for their entangled extensions to several states and observables is presented. The scheme is illustrated on the examples of one and two states and canonical quantum observables, and spin and quasi-spin components. Several new uncertainty relations are displayed. (author)
29 CFR 1607.5 - General standards for validity studies.
2010-07-01
... may rely upon criterion-related validity studies, content validity studies or construct validity... they become accepted by the psychological profession. B. Criterion-related, content, and construct validity. Evidence of the validity of a test or other selection procedure by a criterion-related validity...
Pseudo-complex general relativity
Hess, Peter O; Greiner, Walter
2016-01-01
This volume presents an pseudo-complex extension of General Relativity which addresses these issues and presents proposals for experimental examinations in strong fields near a large mass. General Relativity is a beautiful and well tested theory of gravitation. Nevertheless, it implies conceptual problems like the creation of singularities (Black Holes) as a result of the collapse of large masses, or the appearance of event horizons which exclude parts of the space-time from the observation of external observers. The mathematical and geometrical foundations of this extension are displayed in detail, and applications including orbits and accretion disks around large central masses, neutron stars or cosmological models are introduced. Calculations both for classical and extended applications are often executed in the form of problems with extensive solutions, which makes this volume also a valuable resource for any student of General Relativity.
General relativity and gravitational waves
Weber, Johanna
1961-01-01
An internationally famous physicist and electrical engineer, the author of this text was a pioneer in the investigation of gravitational waves. Joseph Weber's General Relativity and Gravitational Waves offers a classic treatment of the subject. Appropriate for upper-level undergraduates and graduate students, this text remains ever relevant. Brief but thorough in its introduction to the foundations of general relativity, it also examines the elements of Riemannian geometry and tensor calculus applicable to this field.Approximately a quarter of the contents explores theoretical and experimenta
General relativity 50 years old
1966-01-01
In May 1916, 'The Foundations of General Relativity Theory' by Albert Einstein was published in 'Annalen der Physik'. Fifty years later, this major contribution to scientific thought still has a rather isolated position with respect to the main-stream of scientific theory. (In contrast, the Special Theory of Relativity is one of the cornerstones of sub-nuclear physics.) To mark the anniversary of the publication of Einstein's paper a theoretician from CERN discusses the theory and its present status.
Dimensional Analysis and General Relativity
Lovatt, Ian
2009-01-01
Newton's law of gravitation is a central topic in the first-year physics curriculum. A lecturer can go beyond the physical details and use the history of gravitation to discuss the development of scientific ideas; unfortunately, the most recent chapter in this history, general relativity, is not covered in first-year courses. This paper discusses…
The genesis of general relativity
Norton, John; Renn, Jürgen; Sauer, Tilman; Stachel, John
2007-01-01
This four-volume work represents the most comprehensive documentation and study of the creation of general relativity; one of the fundamental physical theories of the 20th century. It comprises key sources from Einstein and others who from the late 19th to the early 20th century contributed to this monumental development. Some of these sources are presented here in translation for the first time. Einstein’s famous Zurich notebook, which documents the pivotal steps toward general relativity, is reproduced here for the first time and transcribed in its entirety. The volumes offer detailed commentaries and analyses of these sources that are based on a close reading of these documents supplemented by interpretations by the leading historians of relativity. All in all, the facets of this work, based on more than a decade of research, combine to constitute one of the most in-depth studies of a scientific revolution ever written.
Testing general relativity on accelerators
Directory of Open Access Journals (Sweden)
Tigran Kalaydzhyan
2015-11-01
Full Text Available Within the general theory of relativity, the curvature of spacetime is related to the energy and momentum of the present matter and radiation. One of the more specific predictions of general relativity is the deflection of light and particle trajectories in the gravitational field of massive objects. Bending angles for electromagnetic waves and light in particular were measured with a high precision. However, the effect of gravity on relativistic massive particles was never studied experimentally. Here we propose and analyze experiments devoted to that purpose. We demonstrate a high sensitivity of the laser Compton scattering at high energy accelerators to the effects of gravity. The main observable – maximal energy of the scattered photons – would experience a significant shift in the ambient gravitational field even for otherwise negligible violation of the equivalence principle. We confirm predictions of general relativity for ultrarelativistic electrons of energy of tens of GeV at a current level of resolution and expect our work to be a starting point of further high-precision studies on current and future accelerators, such as PETRA, European XFEL and ILC.
Conformal Methods in General Relativity
Valiente Kroon, Juan A.
2016-07-01
List of symbols; Preface; 1. Introduction; Part I. Geometric Tools: 2. Differential Geometry; 3. Spacetime spinors; 4. Space spinors; 5. Conformal Geometry; Part II. General Relativity and Conformal Geometry: 6. Conformal extensions of exact solutions; 7. Asymptotic simplicity; 8. The conformal Einstein field equations; 9. Matter models; 10. Asymptotics; Part III. Methods of PDE Theory: 11. The conformal constraint equations; 12. Methods of the theory of hyperbolic differential equations; 13. Hyperbolic reductions; 14. Causality and the Cauchy problem in General Relativity; Part IV. Applications: 15. De Sitter-like spacetimes; 16. Minkowski-like spacetimes; 17. Anti-de Sitter-like spacetimes; 18. Characteristic problems for the conformal field equations; 19. Static solutions; 20. Spatial infinity; 21. Perspectives; References; Index.
General Relativity by Kawaguchi geometry
Directory of Open Access Journals (Sweden)
Tanaka Erico
2013-09-01
Full Text Available We construct a parameterisation invariant Lagrange theory of fields up to second order by using multivector bundles and Kawaguchi geometry. In this setup, the spacetime is an dynamical object which is a submanifold of the greater manifold, and the actual spacetime is the solution of Euler-Lagrange equations. Such theory is a reasonable mathematical foundation to describe an extended theory of Einstein’s general relativity, and is capable of being a stage for unification with other physical fields.
Gravitation. [Book on general relativity
Misner, C. W.; Thorne, K. S.; Wheeler, J. A.
1973-01-01
This textbook on gravitation physics (Einstein's general relativity or geometrodynamics) is designed for a rigorous full-year course at the graduate level. The material is presented in two parallel tracks in an attempt to divide key physical ideas from more complex enrichment material to be selected at the discretion of the reader or teacher. The full book is intended to provide competence relative to the laws of physics in flat space-time, Einstein's geometric framework for physics, applications with pulsars and neutron stars, cosmology, the Schwarzschild geometry and gravitational collapse, gravitational waves, experimental tests of Einstein's theory, and mathematical concepts of differential geometry.
Results from Numerical General Relativity
Baker, John G.
2011-01-01
For several years numerical simulations have been revealing the details of general relativity's predictions for the dynamical interactions of merging black holes. I will review what has been learned of the rich phenomenology of these mergers and the resulting gravitational wave signatures. These wave forms provide a potentially observable record of the powerful astronomical events, a central target of gravitational wave astronomy. Asymmetric radiation can produce a thrust on the system which may accelerate the single black hole resulting from the merger to high relative velocity.
General Relativity, Time and Determinism
Isenberg, James
2016-01-01
Einstein's theory of general relativity models the physical universe using spacetimes which satisfy Einstein's gravitational field equations. To date, Einstein's theory has been enormously successful in modeling observed gravitational phenomena, both at the astrophysical and the cosmological levels. The collection of spacetime solutions of Einstein's equations which have been effectively used for modeling the physical universe is a very small subset of the full set of solutions. Among this larger set, there are many spacetimes in which strange phenomena related to time are present: There are solutions containing regions in which determinism and the predictability of experimental outcomes breaks down (the Taub-NUT spacetimes), and there others in which the breakdown of determinism occurs everywhere (the G\\"odel universe). Should the existence of these strange solutions lead us to question the usefulness of Einstein's theory in modeling physical phenomena? Should it instead lead us to seriously search for stran...
Brownian Motion and General Relativity
O'Hara, Paul
2013-01-01
We construct a model of Brownian Motion on a pseudo-Riemannian manifold associated with general relativity. There are two aspects of the problem: The first is to define a sequence of stopping times associated with the Brownian "kicks" or impulses. The second is to define the dynamics of the particle along geodesics in between the Brownian kicks. When these two aspects are taken together, we can associate various distributions with the motion. We will find that the statistics of space-time events will obey a temperature dependent four dimensional Gaussian distribution defined over the quaternions which locally can be identified with Minkowski space. Analogously, the statistics of the 4-velocities will obey a kind of Maxwell-Juttner distribution. In contrast to previous work, our processes are characterized by two independent proper time variables defined with respect to the laboratory frame: a discrete one corresponding to the stopping times when the impulses take place and a continuous one corresponding to th...
Spacecraft Tests of General Relativity
Anderson, John D.
1997-01-01
Current spacecraft tests of general relativity depend on coherent radio tracking referred to atomic frequency standards at the ground stations. This paper addresses the possibility of improved tests using essentially the current system, but with the added possibility of a space-borne atomic clock. Outside of the obvious measurement of the gravitational frequency shift of the spacecraft clock, a successor to the suborbital flight of a Scout D rocket in 1976 (GP-A Project), other metric tests would benefit most directly by a possible improved sensitivity for the reduced coherent data. For purposes of illustration, two possible missions are discussed. The first is a highly eccentric Earth orbiter, and the second a solar-conjunction experiment to measure the Shapiro time delay using coherent Doppler data instead of the conventional ranging modulation.
The validity of dietary assessment in general practice.
Little, P; Barnett, J; Margetts, B; Kinmonth, A L; Gabbay, J; Thompson, R; Warm, D; Warwick, H; Wooton, S
1999-03-01
To validate a range of dietary assessment instruments in general practice. Using a randomised block design, brief assessment instruments and more complex conventional dietary assessment tools were compared with an accepted "relative" standard--a seven day weighed dietary record. The standard was checked using biomarkers, and by performing test-retest reliability in additional subjects (n = 29). Agreement with weighed record. Percentage agreement with weighed record, rank correlation from scatter plot, rank correlation from Bland-Altman plot. Reliability of the weighed record. Practice nurse treatment room in a single suburban general practice. Patients with risk factors for cardiovascular disease (n = 61) or age/sex stratified general population group (n = 50). Brief self completion dietary assessment tools based on food groups caten during a week show reasonable agreement with the relative standard. For % energy from fat and saturated fat, non-starch polysaccharide, grams of fruit and vegetables and starchy foods consumed the range of agreement with the standard was: median % difference -6% to 12%, rank correlation 0.5 to 0.6. This agreement is of a similar order to the reliability of the weighed record, as good as or better than test standard agreement for more time consuming instruments, and compares favourably with research instruments validated in other settings. Under-reporting of energy intake was common (40%) and more likely if subjects were obese (body mass idex (BMI) > or = 30 60% under-reported; BMI < 30 29%, p < 0.001). Under-reporting of absolute energy intake is common, particularly among obese patients. Simple self assessment tools based on food groups, designed for practice nurse dietary assessment, show acceptable agreement with a standard, and suggest such tools are sufficiently accurate for clinical work, research, and possibly population dietary monitoring.
Action Principle for the Generalized Harmonic Formulation of General Relativity
Brown, J David
2010-01-01
An action principle for the generalized harmonic formulation of general relativity is presented. The action is a functional of the spacetime metric and the gauge source vector. The Z4 formulation of general relativity also can be defined by an action principle, as discussed by Bona, Bona--Casas and Palenzuela. The relationship between the generalized harmonic and Z4 actions is presented in detail.
Validation of the diagnosis of autism in general practitioner records
Fombonne, Eric; Heavey, Lisa; Smeeth, Liam; Rodrigues, Laura C; Cook, Claire; Smith, Peter G; Meng, Linyan; Hall, Andrew J
2004-01-01
Background We report on the validity of the computerized diagnoses of autism in a large case-control study investigating the possible association between autism and the measles, mumps and rubella vaccine in the UK using the General Practitioner Research Database (GPRD). We examined anonymized copies of all relevant available clinical reports, including general practitioners' (GP) notes, consultant, speech therapy and educational psychologists reports, on 318 subjects born between 1973 and 1997 with a diagnosis of autism or a related disorder recorded in their electronic general practice record. Methods Data were abstracted to a case validation form allowing for the identification of developmental symptoms relevant to the diagnosis of pervasive developmental disorders (PDDs). Information on other background clinical and familial features was also abstracted. A subset of 50 notes was coded independently by 2 raters to derive reliability estimates for key clinical characteristics. Results For 294 subjects (92.5%) the diagnosis of PDD was confirmed after review of the records. Of these, 180 subjects (61.2%) fulfilled criteria for autistic disorder. The mean age at first recording of a PDD diagnosis in the GPRD database was 6.3 years (SD = 4.6). Consistent with previous estimates, the proportion of subjects experiencing regression in the course of their development was 19%. Inter-rater reliability for the presence of a PDD diagnosis was good (kappa = .73), and agreement on clinical features such as regression, age of parental recognition of first symptoms, language delay and presence of epilepsy was also good (kappas ranging from .56 to 1.0). Conclusions This study provides evidence that the positive predictive value of a diagnosis of autism recorded in the GPRD is high. PMID:15113435
Validation of the diagnosis of autism in general practitioner records
Directory of Open Access Journals (Sweden)
Smith Peter G
2004-03-01
Full Text Available Abstract Background We report on the validity of the computerized diagnoses of autism in a large case-control study investigating the possible association between autism and the measles, mumps and rubella vaccine in the UK using the General Practitioner Research Database (GPRD. We examined anonymized copies of all relevant available clinical reports, including general practitioners' (GP notes, consultant, speech therapy and educational psychologists reports, on 318 subjects born between 1973 and 1997 with a diagnosis of autism or a related disorder recorded in their electronic general practice record. Methods Data were abstracted to a case validation form allowing for the identification of developmental symptoms relevant to the diagnosis of pervasive developmental disorders (PDDs. Information on other background clinical and familial features was also abstracted. A subset of 50 notes was coded independently by 2 raters to derive reliability estimates for key clinical characteristics. Results For 294 subjects (92.5% the diagnosis of PDD was confirmed after review of the records. Of these, 180 subjects (61.2% fulfilled criteria for autistic disorder. The mean age at first recording of a PDD diagnosis in the GPRD database was 6.3 years (SD = 4.6. Consistent with previous estimates, the proportion of subjects experiencing regression in the course of their development was 19%. Inter-rater reliability for the presence of a PDD diagnosis was good (kappa = .73, and agreement on clinical features such as regression, age of parental recognition of first symptoms, language delay and presence of epilepsy was also good (kappas ranging from .56 to 1.0. Conclusions This study provides evidence that the positive predictive value of a diagnosis of autism recorded in the GPRD is high.
Perturbative dynamics of quantum general relativity
Donoghue, John F.
1997-01-01
The quantum theory of General Relativity at low energy exists and is of the form called "effective field theory". In this talk I describe the ideas of effective field theory and its application to General Relativity.
Numerical Hydrodynamics in General Relativity
Directory of Open Access Journals (Sweden)
Font José A.
2000-05-01
Full Text Available The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A representative sample of available numerical schemes is discussed and particular emphasis is paid to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of relevant astrophysical simulations in strong gravitational fields, including gravitational collapse, accretion onto black holes and evolution of neutron stars, is also presented.
Numerical Hydrodynamics in General Relativity
Directory of Open Access Journals (Sweden)
Font José A.
2003-01-01
Full Text Available The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. With respect to an earlier version of the article, the present update provides additional information on numerical schemes, and extends the discussion of astrophysical simulations in general relativistic hydrodynamics. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A large sample of available numerical schemes is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of astrophysical simulations in strong gravitational fields is presented. These include gravitational collapse, accretion onto black holes, and hydrodynamical evolutions of neutron stars. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances on the formulation of the gravitational field and hydrodynamic equations and the numerical methodology designed to solve them.
A logic road from special relativity to general relativity
Andréka, Hajnal; Madarász, Judit X.; Németi, István; Székely, Gergely
2010-01-01
We present a streamlined axiom system of special relativity in first-order logic. From this axiom system we "derive" an axiom system of general relativity in two natural steps. We will also see how the axioms of special relativity transform into those of general relativity. This way we hope to make general relativity more accessible for the non-specialist.
Conformal methods in general relativity
Valiente Kroon, Juan A
2016-01-01
This book offers a systematic exposition of conformal methods and how they can be used to study the global properties of solutions to the equations of Einstein's theory of gravity. It shows that combining these ideas with differential geometry can elucidate the existence and stability of the basic solutions of the theory. Introducing the differential geometric, spinorial and PDE background required to gain a deep understanding of conformal methods, this text provides an accessible account of key results in mathematical relativity over the last thirty years, including the stability of de Sitter and Minkowski spacetimes. For graduate students and researchers, this self-contained account includes useful visual models to help the reader grasp abstract concepts and a list of further reading, making this the perfect reference companion on the topic.
Pulsar timing and general relativity
Backer, D. C.; Hellings, R. W.
1986-01-01
Techniques are described for accounting for relativistic effects in the analysis of pulsar signals. Design features of instrumentation used to achieve millisecond accuracy in the signal measurements are discussed. The accuracy of the data permits modeling the pulsar physical characteristics from the natural glitches in the emissions. Relativistic corrections are defined for adjusting for differences between the pulsar motion in its spacetime coordinate system relative to the terrestrial coordinate system, the earth's motion, and the gravitational potentials of solar system bodies. Modifications of the model to allow for a binary pulsar system are outlined, including treatment of the system as a point mass. Finally, a quadrupole model is presented for gravitational radiation and techniques are defined for using pulsars in the search for gravitational waves.
Further Validation of the Relational Ethics Scale.
Hargrave, Terry D.; Bomba, Anne K.
1993-01-01
Conducted two studies to examine effects of marital status and age on Relational Ethics Scale. Study One indicated that scale was reliable and valid among single, never married young adults (n=162). Study Two examined differences between scores for this population and original normative sample. Findings suggest that ethical issues with…
General relativity and mathematics; Relatividad General y Matematicas
Energy Technology Data Exchange (ETDEWEB)
Mars, M.
2015-07-01
General relativity is more than a theory of gravity, since any physical process occupies space and lasts for a time, forcing to reconcile that physical theory that describes what the dynamic nature of space-time itself. (Author)
Development and validation of a general population renal risk score
Halbesma, N.; Jansen, D.F.; Heymans, M.W.; Stolk, R.P.; de Jong, P.E.; Gansevoort, R.T.
2011-01-01
Background and objectives There is a need for prediction scores that identify individuals at increased risk for developing progressive chronic kidney disease (CKD). Therefore, this study was performed to develop and validate a "renal risk score" for the general population. Design, setting,
Centennial of general relativity a celebration
2017-01-01
It has been over 100 years since the presentation of the Theory of General Relativity by Albert Einstein, in its final formulation, to the Royal Prussian Academy of Sciences. To celebrate 100 years of general relativity, World Scientific publishes this volume with a dual goal: to assess the current status of the field of general relativity in broad terms, and discuss future directions. The volume thus consists of broad overviews summarizing major developments over the past decades and their perspective contributions.
A crosscultural validation of a test of science related attitudes
Khalili, Khalil Y.
A test for measuring science attitudes, named Test of Science Related Attitudes (TOSRA), was initially developed in Australia by Fraser (1977, 1978). This study investigated the crosscultural validity of this instrument when used with American high school students. Three hundred and thirty-six students (12th and 11th graders) in three high schools in suburban Chicago took the test. The results of the study, confirming previous validation of the test, revealed that the seven subscales of TOSRA were, in general, highly reliable. The discriminant validity of each of these scales, however, was found to be generally low. The item/scale correlation for all but four items of the test met Shrigley's (Journal of Research in Science Teaching, 20(1), 87-89, 1983) criterion of being more than 0.30. The results of the principal components with varimax rotation did not support the distinctiveness of the subscale structure of the test.
General Relativity in the Undergraduate Physics Curriculum
Hartle, James B.
2005-01-01
Einstein's general relativity is increasingly important in contemporary physics on the frontiers of both the very largest distance scales (astrophysics and cosmology) and the very smallest(elementary particle physics). This paper makes the case for a `physics first' approach to introducing general relativity to undergraduate physics majors.
General Relativity in (1 + 1) Dimensions
Boozer, A. D.
2008-01-01
We describe a theory of gravity in (1 + 1) dimensions that can be thought of as a toy model of general relativity. The theory should be a useful pedagogical tool, because it is mathematically much simpler than general relativity but shares much of the same conceptual structure; in particular, it gives a simple illustration of how gravity arises…
Emergency general surgery specific frailty index: A validation study.
Orouji Jokar, Tahereh; Ibraheem, Kareem; Rhee, Peter; Kulavatunyou, Narong; Haider, Ansab; Phelan, Herb A; Fain, Mindy; Mohler, Martha Jane; Joseph, Bellal
2016-08-01
Assessment of operative risk in geriatric patients undergoing emergency general surgery (EGS) is challenging. Frailty is an established measure for risk assessment in surgical cases. The aim of our study was to validate a modified 15-variable EGS-specific frailty index (EGSFI). We prospectively collected geriatric (age older than 65 years) EGS patients for 2 years. Postoperative complications were collected. Frailty index was calculated for 200 patients based on their preadmission condition using 50-variable modified Rockwood frailty index. Emergency general surgery-specific frailty index was developed based on the regression model for complications and the most significant factors in the frailty index. Receiver operating characteristic curve analysis was performed to determine cutoff for frail status. We validated our results using 60 patients for predicting complications. A total of 260 patients (developing, 200; validation, 60) were enrolled in this study. Mean age was 71 ± 11 years, and 33% developed complications. Most common complications were pneumonia (12%), urinary tract infection (9%), and wound infection (7%). Univariate analysis identified 15 variables significantly associated with complications that were used to develop the EGSFI. A cutoff frailty score of 0.325 was identified using receiver operating characteristic curve analysis for frail status. Sixty patients (frail, 18; nonfrail, 42) were enrolled in the validation cohort. Frail patients were more likely to have postoperative complications (47% vs. 20%; p II.
The Confrontation between General Relativity and Experiment
Directory of Open Access Journals (Sweden)
Will Clifford
2001-01-01
Full Text Available The status of experimental tests of general relativity and of theoretical frameworks for analysing them are reviewed. Einstein's equivalence principle (EEP is well supported by experiments such as the Eötvös experiment, tests of special relativity, and the gravitational redshift experiment. Future tests of EEP and of the inverse square law will search for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, and the Nordtvedt effect in lunar motion. Gravitational wave damping has been detected in an amount that agrees with general relativity to half a percent using the Hulse-Taylor binary pulsar, and new binary pulsar systems may yield further improvements.When direct observation of gravitational radiation from astrophysical sources begins, new tests of general relativity will be possible.
Black hole dynamics in general relativity
Indian Academy of Sciences (India)
Abstract. Basic features of dynamical black holes in full, non-linear general relativity are summarized in a pedagogical fashion. Qualitative properties of the evolution of various horizons follow directly from the celebrated Raychaudhuri equation.
Einstein and General Relativity: Historical Perspectives.
Chandrasekhar, S.
1979-01-01
This paper presented in the 1978 Oppenheimer Memorial Lecture at Los Alamos Scientific Laboratories on August 17, 1978, discusses Einstein's contributions to physics, in particular, his discovery of the general theory of relativity. (HM)
An observer principle for general relativity
Dupre, Maurice J
2014-01-01
We give a mathematical uniqueness theorem which in particular shows that symmetric tensors in general relativity are uniquely determined by their monomial functions on the light cone. Thus, for an observer to observe a tensor at an event in general relativity is to contract with the velocity vector of the observer, repeatedly to the rank of the tensor. Thus two symmetric tensors observed to be equal by all observers at a specific event are necessarily equal at that event.
A golden age of general relativity? Some remarks on the history of general relativity
Goenner, Hubert
2017-03-01
This article deals with the concepts "renaissance" and "low water mark between 1925 and 1955" of general relativity suggested in the literature. By empirical data, it is shown that no such period did exist. Research on general relativity continued continuously since the 1920s interrupted only by the second world war. On a broad scale, research on general relativity started only after 1945.
Teaching General Relativity to the Layperson
Egdall, Mark
2009-01-01
This paper describes a lay course on general relativity (GR) given at the Osher Lifelong Learning Institute at Florida International University. It is presented in six hour-and-a-half weekly sessions. Other courses offered by the author include special relativity (which precedes the course described here), quantum theory, and cosmology. Students…
The Confrontation between General Relativity and Experiment.
Will, Clifford M
2014-01-01
The status of experimental tests of general relativity and of theoretical frameworks for analyzing them is reviewed and updated. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of local Lorentz invariance and clock experiments. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, the Nordtvedt effect in lunar motion, and frame-dragging. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse-Taylor binary pulsar, and a growing family of other binary pulsar systems is yielding new tests, especially of strong-field effects. Current and future tests of relativity will center on strong gravity and gravitational waves.
Relational Coordination in Danish General Practice
DEFF Research Database (Denmark)
Lundstrøm, Sanne Lykke
and relationship networks through which work is coordinated across functional and organisational boundaries. Previous studies have shown that relational coordination is positively associated with delivery of care for patients with chronic illness. Organisational social capital is used when analysing...... the psychosocial work environment in organisations, and is seen as a powerful resources for improving organisational performance. Relational coordination and organisational social capital may oer new insight and opportunities for general practice to learn. General practice provides cost-efficient, first......This PhD dissertation is a product of my PhD project carried out in collaboration between DTU Management Engineering, The Technical University of Denmark, Research Unit for General Practice at University of Southern Denmark, and Research Unit for General Practice at University of Copenhagen...
Electromagnetic Radiation Reaction in General Relativity.
O'Donnell, Nuala
Available from UMI in association with The British Library. This thesis examines the electromagnetic radiation reaction felt by a charged body falling freely in an external gravitational field in general relativity. The original objective was to find a new derivation of the radiation reaction force F^{i} of DeWitt and DeWitt^1 which was calculated for the special case of a point charge falling in slow motion in a weak, static gravitational field: F ^{i} = {2over 3}e^2R^{i}_{0j0 }v^{j}. This may be thought of as a local expression since it involves the particle's velocity v^{j } and the local Riemann curvature tensor R ^{i}_{0j0}. Its derivation involves integrals over the whole history of the particle, covering distances of approximately the length scale on which R^{i}_{0j0 } changes. This is different from calculations of the Abraham-Lorentz force of flat space-time involving integrals over distances only a few times the size of the charge. This work was motivated by the wish to find a "local" derivation of the local reaction force. Using Schutz's^2 local initial value method to solve the problem of a charged, rigid, spherically symmetric body moving in an external gravitational field of arbitrary metric. Calculations are done in a Riemann normal coordinate system ^3 and are only valid in a normal neighbourhood of the origin, where geodesics have not begun to cross one another. We solve Maxwell's equations for the self -force by making a slow-motion approximation and keeping terms to first order only in the Riemann tensor and velocity. It is surprising that we find no local radiation reaction. Consider two particles in a static spacetime with the same initial conditions at t = 0. Particle A is that of DeWitt and DeWitt; it feels a reaction force F^{i} = {2over 3}e^2R^{i }_{0j0}v^{j}. Particle B is accelerated from rest to the same small velocity; it feels no reaction force. The two particles therefore follow different trajectories. We conclude that there is a
Allen, Rae M.; Abdulwadud, Omar A.; Jones, Michael P.; Abramson, Michael; Walters, Haydn
2000-01-01
Using the responses of 115 adults attending an asthma educator training course, the Asthma General Knowledge Questionnaire for Adults (AGKQA) was found to be an acceptably valid and reliable measure for assessing knowledge related to the management of asthma by adults. (Author/MKA)
Introduction to 2-spinors in general relativity
O'Donnell, Peter
2003-01-01
This book deals with 2-spinors in general relativity, beginning by developing spinors in a geometrical way rather than using representation theory, which can be a little abstract. This gives the reader greater physical intuition into the way in which spinors behave. The book concentrates on the algebra and calculus of spinors connected with curved space-time. Many of the well-known tensor fields in general relativity are shown to have spinor counterparts. An analysis of the Lanczos spinor concludes the book, and some of the techniques so far encountered are applied to this. Exercises play an i
Toposes in General Theory of Relativity
Guts, Alexandr K.; Grinkevich, Egor B.
1996-01-01
We study in this paper different topos-theoretical approaches to the problem of construction of General Theory of Relativity. In general case the resulting space-time theory will be non-classical, different from that of the usual Einstein theory of space-time. This is a new theory of space-time, created in a purely logical manner. Four possibitities are investigated: axiomatic approach to causal theory of space-time, the smooth toposes as a models of Theory of Relativity, Synthetic Theory of ...
General Relativity Revisited: Generalized Nordstr\\"om Theory
Bengtsson, Johan
2016-01-01
In 1945 Einstein concluded that [1]: 'The present theory of relativity is based on a division of physical reality into a metric field (gravitation) on the one hand, and into an electromagnetic field and matter on the other hand. In reality space will probably be of a uniform character and the present theory be valid only as a limiting case. For large densities of field and of matter, the field equations and even the field variables which enter into them will have no real significance.'. The dichotomy can be resolved by introducing a scalar field/potential algebraically related to the Ricci tensor for which the corresponding metric is free of additional singularities. Hence, although a fundamentally nonlinear theory, the scalar field/potential provides an analytic framework for interacting particles; described by linear superposition. The stress tensor for the scalar field includes both the sources of and the energy-momentum for the gravitational field, and has zero covariant and ordinary divergence. Hence, th...
Tests of General Relativity with GW150914.
Abbott, B P; Abbott, R; Abbott, T D; Abernathy, M R; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Adya, V B; Affeldt, C; Agathos, M; Agatsuma, K; Aggarwal, N; Aguiar, O D; Aiello, L; Ain, A; Ajith, P; Allen, B; Allocca, A; Altin, P A; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C C; Areeda, J S; Arnaud, N; Arun, K G; Ascenzi, S; Ashton, G; Ast, M; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Babak, S; Bacon, P; Bader, M K M; Baker, P T; Baldaccini, F; Ballardin, G; Ballmer, S W; Barayoga, J C; Barclay, S E; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barta, D; Bartlett, J; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Baune, C; Bavigadda, V; Bazzan, M; Behnke, B; Bejger, M; Bell, A S; Bell, C J; Berger, B K; Bergman, J; Bergmann, G; Berry, C P L; Bersanetti, D; Bertolini, A; Betzwieser, J; Bhagwat, S; Bhandare, R; Bilenko, I A; Billingsley, G; Birch, J; Birney, R; Birnholtz, O; Biscans, S; Bisht, A; Bitossi, M; Biwer, C; Bizouard, M A; Blackburn, J K; Blair, C D; Blair, D G; Blair, R M; Bloemen, S; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bogan, C; Bohe, A; Bojtos, P; Bond, C; Bondu, F; Bonnand, R; Boom, B A; Bork, R; Boschi, V; Bose, S; Bouffanais, Y; Bozzi, A; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Brillet, A; Brinkmann, M; Brisson, V; Brockill, P; Brooks, A F; Brown, D A; Brown, D D; Brown, N M; Buchanan, C C; Buikema, A; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Cahillane, C; Calderón Bustillo, J; Callister, T; Calloni, E; Camp, J B; Cannon, K C; Cao, J; Capano, C D; Capocasa, E; Carbognani, F; Caride, S; Casanueva Diaz, J; Casentini, C; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C B; Cerboni Baiardi, L; Cerretani, G; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chan, M; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, H Y; Chen, Y; Cheng, C; Chincarini, A; Chiummo, A; Cho, H S; Cho, M; Chow, J H; Christensen, N; Chu, Q; Chua, S; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P-F; Colla, A; Collette, C G; Cominsky, L; Constancio, M; Conte, A; Conti, L; Cook, D; Corbitt, T R; Cornish, N; Corsi, A; Cortese, S; Costa, C A; Coughlin, M W; Coughlin, S B; Coulon, J-P; Countryman, S T; Couvares, P; Cowan, E E; Coward, D M; Cowart, M J; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Cripe, J; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Dal Canton, T; Danilishin, S L; D'Antonio, S; Danzmann, K; Darman, N S; Dattilo, V; Dave, I; Daveloza, H P; Davier, M; Davies, G S; Daw, E J; Day, R; DeBra, D; Debreczeni, G; Degallaix, J; De Laurentis, M; Deléglise, S; Del Pozzo, W; Denker, T; Dent, T; Dereli, H; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; Díaz, M C; Di Fiore, L; Di Giovanni, M; Di Lieto, A; Di Pace, S; Di Palma, I; Di Virgilio, A; Dojcinoski, G; Dolique, V; Donovan, F; Dooley, K L; Doravari, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Ducrot, M; Dwyer, S E; Edo, T B; Edwards, M C; Effler, A; Eggenstein, H-B; Ehrens, P; Eichholz, J; Eikenberry, S S; Engels, W; Essick, R C; Etzel, T; Evans, M; Evans, T M; Everett, R; Factourovich, M; Fafone, V; Fair, H; Fairhurst, S; Fan, X; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fays, M; Fehrmann, H; Fejer, M M; Ferrante, I; Ferreira, E C; Ferrini, F; Fidecaro, F; Fiori, I; Fiorucci, D; Fisher, R P; Flaminio, R; Fletcher, M; Fournier, J-D; Franco, S; Frasca, S; Frasconi, F; Frei, Z; Freise, A; Frey, R; Frey, V; Fricke, T T; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gabbard, H A G; Gair, J R; Gammaitoni, L; Gaonkar, S G; Garufi, F; Gatto, A; Gaur, G; Gehrels, N; Gemme, G; Gendre, B; Genin, E; Gennai, A; George, J; Gergely, L; Germain, V; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gill, K; Glaefke, A; Goetz, E; Goetz, R; Gondan, L; González, G; Gonzalez Castro, J M; Gopakumar, A; Gordon, N A; Gorodetsky, M L; Gossan, S E; Gosselin, M; Gouaty, R; Graef, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greco, G; Green, A C; Groot, P; Grote, H; Grunewald, S; Guidi, G M; Guo, X; Gupta, A; Gupta, M K; Gushwa, K E; Gustafson, E K; Gustafson, R; Hacker, J J; Hall, B R; Hall, E D; Hammond, G; Haney, M; Hanke, M M; Hanks, J; Hanna, C; Hannam, M D; Hanson, J; Hardwick, T; Harms, J; Harry, G M; Harry, I W; Hart, M J; Hartman, M T; Haster, C-J; Haughian, K; Healy, J; Heidmann, A; Heintze, M C; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Hennig, J; Heptonstall, A W; Heurs, M; Hild, S; Hoak, D; Hodge, K A; Hofman, D; Hollitt, S E; Holt, K; Holz, D E; Hopkins, P; Hosken, D J; Hough, J; Houston, E A; Howell, E J; Hu, Y M; Huang, S; Huerta, E A; Huet, D; Hughey, B; Husa, S; Huttner, S H; Huynh-Dinh, T; Idrisy, A; Indik, N; Ingram, D R; Inta, R; Isa, H N; Isac, J-M; Isi, M; Islas, G; Isogai, T; Iyer, B R; Izumi, K; Jacqmin, T; Jang, H; Jani, K; Jaranowski, P; Jawahar, S; Jiménez-Forteza, F; Johnson, W W; Johnson-McDaniel, N K; Jones, D I; Jones, R; Jonker, R J G; Ju, L; Haris, M K; Kalaghatgi, C V; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Karki, S; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, S; Kaur, T; Kawabe, K; Kawazoe, F; Kéfélian, F; Kehl, M S; Keitel, D; Kelley, D B; Kells, W; Kennedy, R; Key, J S; Khalaidovski, A; Khalili, F Y; Khan, I; Khan, S; Khan, Z; Khazanov, E A; Kijbunchoo, N; Kim, C; Kim, J; Kim, K; Kim, Nam-Gyu; Kim, Namjun; Kim, Y-M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Kleybolte, L; Klimenko, S; Koehlenbeck, S M; Kokeyama, K; Koley, S; Kondrashov, V; Kontos, A; Korobko, M; Korth, W Z; Kowalska, I; Kozak, D B; Kringel, V; Krishnan, B; Królak, A; Krueger, C; Kuehn, G; Kumar, P; Kuo, L; Kutynia, A; Lackey, B D; Landry, M; Lange, J; Lantz, B; Lasky, P D; Lazzarini, A; Lazzaro, C; Leaci, P; Leavey, S; Lebigot, E O; Lee, C H; Lee, H K; Lee, H M; Lee, K; Lenon, A; Leonardi, M; Leong, J R; Leroy, N; Letendre, N; Levin, Y; Levine, B M; Li, T G F; Libson, A; Littenberg, T B; Lockerbie, N A; Logue, J; Lombardi, A L; London, L T; Lord, J E; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J D; Lousto, C O; Lovelace, G; Lück, H; Lundgren, A P; Luo, J; Lynch, R; Ma, Y; MacDonald, T; Machenschalk, B; MacInnis, M; Macleod, D M; Magaña-Sandoval, F; Magee, R M; Mageswaran, M; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Mandel, I; Mandic, V; Mangano, V; Mansell, G L; Manske, M; Mantovani, M; Marchesoni, F; Marion, F; Márka, S; Márka, Z; Markosyan, A S; Maros, E; Martelli, F; Martellini, L; Martin, I W; Martin, R M; Martynov, D V; Marx, J N; Mason, K; Masserot, A; Massinger, T J; Masso-Reid, M; Matichard, F; Matone, L; Mavalvala, N; Mazumder, N; Mazzolo, G; McCarthy, R; McClelland, D E; McCormick, S; McGuire, S C; McIntyre, G; McIver, J; McManus, D J; McWilliams, S T; Meacher, D; Meadors, G D; Meidam, J; Melatos, A; Mendell, G; Mendoza-Gandara, D; Mercer, R A; Merilh, E; Merzougui, M; Meshkov, S; Messenger, C; Messick, C; Meyers, P M; Mezzani, F; Miao, H; Michel, C; Middleton, H; Mikhailov, E E; Milano, L; Miller, J; Millhouse, M; Minenkov, Y; Ming, J; Mirshekari, S; Mishra, C; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moggi, A; Mohan, M; Mohapatra, S R P; Montani, M; Moore, B C; Moore, C J; Moraru, D; Moreno, G; Morriss, S R; Mossavi, K; Mours, B; Mow-Lowry, C M; Mueller, C L; Mueller, G; Muir, A W; Mukherjee, Arunava; Mukherjee, D; Mukherjee, S; Mukund, N; Mullavey, A; Munch, J; Murphy, D J; Murray, P G; Mytidis, A; Nardecchia, I; Naticchioni, L; Nayak, R K; Necula, V; Nedkova, K; Nelemans, G; Neri, M; Neunzert, A; Newton, G; Nguyen, T T; Nielsen, A B; Nissanke, S; Nitz, A; Nocera, F; Nolting, D; Normandin, M E; Nuttall, L K; Oberling, J; Ochsner, E; O'Dell, J; Oelker, E; Ogin, G H; Oh, J J; Oh, S H; Ohme, F; Oliver, M; Oppermann, P; Oram, Richard J; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Pai, A; Pai, S A; Palamos, J R; Palashov, O; Palomba, C; Pal-Singh, A; Pan, H; Pan, Y; Pankow, C; Pannarale, F; Pant, B C; Paoletti, F; Paoli, A; Papa, M A; Paris, H R; Parker, W; Pascucci, D; Pasqualetti, A; Passaquieti, R; Passuello, D; Patricelli, B; Patrick, Z; Pearlstone, B L; Pedraza, M; Pedurand, R; Pekowsky, L; Pele, A; Penn, S; Perreca, A; Pfeiffer, H P; Phelps, M; Piccinni, O; Pichot, M; Piergiovanni, F; Pierro, V; Pillant, G; Pinard, L; Pinto, I M; Pitkin, M; Poggiani, R; Popolizio, P; Post, A; Powell, J; Prasad, J; Predoi, V; Premachandra, S S; Prestegard, T; Price, L R; Prijatelj, M; Principe, M; Privitera, S; Prix, R; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; Pürrer, M; Qi, H; Qin, J; Quetschke, V; Quintero, E A; Quitzow-James, R; Raab, F J; Rabeling, D S; Radkins, H; Raffai, P; Raja, S; Rakhmanov, M; Rapagnani, P; Raymond, V; Razzano, M; Re, V; Read, J; Reed, C M; Regimbau, T; Rei, L; Reid, S; Reitze, D H; Rew, H; Reyes, S D; Ricci, F; Riles, K; Robertson, N A; Robie, R; Robinet, F; Rocchi, A; Rolland, L; Rollins, J G; Roma, V J; Romano, R; Romanov, G; Romie, J H; Rosińska, D; Rowan, S; Rüdiger, A; Ruggi, P; Ryan, K; Sachdev, S; Sadecki, T; Sadeghian, L; Salconi, L; Saleem, M; Salemi, F; Samajdar, A; Sammut, L; Sanchez, E J; Sandberg, V; Sandeen, B; Sanders, J R; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Sauter, O; Savage, R L; Sawadsky, A; Schale, P; Schilling, R; Schmidt, J; Schmidt, P; Schnabel, R; Schofield, R M S; Schönbeck, A; Schreiber, E; Schuette, D; Schutz, B F; Scott, J; Scott, S M; Sellers, D; Sengupta, A S; Sentenac, D; Sequino, V; Sergeev, A; Serna, G; Setyawati, Y; Sevigny, A; Shaddock, D A; Shah, S; Shahriar, M S; Shaltev, M; Shao, Z; Shapiro, B; Shawhan, P; Sheperd, A; Shoemaker, D H; Shoemaker, D M; Siellez, K; Siemens, X; Sigg, D; Silva, A D; Simakov, D; Singer, A; Singer, L P; Singh, A; Singh, R; Singhal, A; Sintes, A M; Slagmolen, B J J; Smith, J R; Smith, N D; Smith, R J E; Son, E J; Sorazu, B; Sorrentino, F; Souradeep, T; Srivastava, A K; Staley, A; Steinke, M; Steinlechner, J; Steinlechner, S; Steinmeyer, D; Stephens, B C; Stone, R; Strain, K A; Straniero, N; Stratta, G; Strauss, N A; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Sun, L; Sutton, P J; Swinkels, B L; Szczepańczyk, M J; Tacca, M; Talukder, D; Tanner, D B; Tápai, M; Tarabrin, S P; Taracchini, A; Taylor, R; Theeg, T; Thirugnanasambandam, M P; Thomas, E G; Thomas, M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Tiwari, S; Tiwari, V; Tokmakov, K V; Tomlinson, C; Tonelli, M; Torres, C V; Torrie, C I; Töyrä, D; Travasso, F; Traylor, G; Trifirò, D; Tringali, M C; Trozzo, L; Tse, M; Turconi, M; Tuyenbayev, D; Ugolini, D; Unnikrishnan, C S; Urban, A L; Usman, S A; Vahlbruch, H; Vajente, G; Valdes, G; Vallisneri, M; van Bakel, N; van Beuzekom, M; van den Brand, J F J; Van Den Broeck, C; Vander-Hyde, D C; van der Schaaf, L; van Heijningen, J V; van Veggel, A A; Vardaro, M; Vass, S; Vasúth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Viceré, A; Vinciguerra, S; Vine, D J; Vinet, J-Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Voss, D; Vousden, W D; Vyatchanin, S P; Wade, A R; Wade, L E; Wade, M; Walker, M; Wallace, L; Walsh, S; Wang, G; Wang, H; Wang, M; Wang, X; Wang, Y; Ward, R L; Warner, J; Was, M; Weaver, B; Wei, L-W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Weßels, P; Westphal, T; Wette, K; Whelan, J T; White, D J; Whiting, B F; Williams, D; Williams, R D; Williamson, A R; Willis, J L; Willke, B; Wimmer, M H; Winkler, W; Wipf, C C; Wittel, H; Woan, G; Worden, J; Wright, J L; Wu, G; Yablon, J; Yam, W; Yamamoto, H; Yancey, C C; Yap, M J; Yu, H; Yvert, M; Zadrożny, A; Zangrando, L; Zanolin, M; Zendri, J-P; Zevin, M; Zhang, F; Zhang, L; Zhang, M; Zhang, Y; Zhao, C; Zhou, M; Zhou, Z; Zhu, X J; Zucker, M E; Zuraw, S E; Zweizig, J; Boyle, M; Campanelli, M; Hemberger, D A; Kidder, L E; Ossokine, S; Scheel, M A; Szilagyi, B; Teukolsky, S; Zlochower, Y
2016-06-03
The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13} km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.
Black hole dynamics in general relativity
Indian Academy of Sciences (India)
69, No. 1. — journal of. July 2007 physics pp. 77–92. Black hole dynamics in general relativity. ABHAY ASHTEKAR. 1,2. 1. Institute for Gravitational Physics and Geometry, Physics Department,. Penn State University, University Park, PA 16802, USA. 2. Institute for Theoretical Physics, University of Utrecht, Princetonplein 5,.
Summary of classical general relativity workshop
Indian Academy of Sciences (India)
In the classical general relativity workshop, ten lectures were presented on various topics. The topics included aspects of black-hole physics, gravitational collapse and the formation of black holes, specific stellar models like a superdense star, method of extracting solutions by exploiting Noether symmetry, brane world and.
The rocket problem in general relativity
Henriques, Pedro G
2011-01-01
We derive the covariant optimality conditions for rocket trajectories in general relativity, with and without a bound on the magnitude of the proper acceleration. The resulting theory is then applied to solve two specific problems: the minimum fuel consumption transfer between two galaxies in a FLRW model, and between two stable circular orbits in the Schwarzschild spacetime.
Generalization of Gibbs Entropy and Thermodynamic Relation
Park, Jun Chul
2010-01-01
In this paper, we extend Gibbs's approach of quasi-equilibrium thermodynamic processes, and calculate the microscopic expression of entropy for general non-equilibrium thermodynamic processes. Also, we analyze the formal structure of thermodynamic relation in non-equilibrium thermodynamic processes.
The confrontation between general relativity and experiment
Indian Academy of Sciences (India)
The binary pulsar provides tests of gravitational wave damping and of strong-field general relativity. Future experiments, such as the gravity probe B gyroscope experiment, a satellite test of the equivalence principle, and tests of gravity at short distance to look for extra spatial dimensions could further constrain alternatives to ...
A General Method of Empirical Q-matrix Validation.
de la Torre, Jimmy; Chiu, Chia-Yi
2016-06-01
In contrast to unidimensional item response models that postulate a single underlying proficiency, cognitive diagnosis models (CDMs) posit multiple, discrete skills or attributes, thus allowing CDMs to provide a finer-grained assessment of examinees' test performance. A common component of CDMs for specifying the attributes required for each item is the Q-matrix. Although construction of Q-matrix is typically performed by domain experts, it nonetheless, to a large extent, remains a subjective process, and misspecifications in the Q-matrix, if left unchecked, can have important practical implications. To address this concern, this paper proposes a discrimination index that can be used with a wide class of CDM subsumed by the generalized deterministic input, noisy "and" gate model to empirically validate the Q-matrix specifications by identifying and replacing misspecified entries in the Q-matrix. The rationale for using the index as the basis for a proposed validation method is provided in the form of mathematical proofs to several relevant lemmas and a theorem. The feasibility of the proposed method was examined using simulated data generated under various conditions. The proposed method is illustrated using fraction subtraction data.
A short course in general relativity
Foster, James
2006-01-01
Suitable for a one-semester course in general relativity for senior undergraduates or beginning graduate students, this text clarifies the mathematical aspects of Einstein's theory of relativity without sacrificing physical understanding. The text begins with an exposition of those aspects of tensor calculus and differential geometry needed for a proper treatment of the subject. The discussion then turns to the spacetime of general relativity and to geodesic motion. A brief consideration of the field equations is followed by a discussion of physics in the vicinity of massive objects, including an elementary treatment of black holes and rotating objects. The main text concludes with introductory chapters on gravitational radiation and cosmology. This new third edition has been updated to take account of fresh observational evidence and experiments. It includes new sections on the Kerr solution (in Chapter 4) and cosmological speeds of recession (in Chapter 6). A more mathematical treatment of tensors and manif...
General Relativity and John Archibald Wheeler
Ciufolini, Ignazio
2010-01-01
Observational and experimental data pertaining to gravity and cosmology are changing our view of the Universe. General relativity is a fundamental key for the understanding of these observations and its theory is undergoing a continuing enhancement of its intersection with observational and experimental data. These data include direct observations and experiments carried out in our solar system, among which there are direct gravitational wave astronomy, frame dragging and tests of gravitational theories from solar system and spacecraft observations. This book explores John Archibald Wheeler's seminal and enduring contributions in relativistic astrophysics and includes: the General Theory of Relativity and Wheeler's influence; recent developments in the confrontation of relativity with experiments; the theory describing gravitational radiation, and its detection in Earth-based and space-based interferometer detectors as well as in Earth-based bar detectors; the mathematical description of the initial value pro...
Wirz A. Melchers K. G. Schultheiss S. & Kleinmann M.
2014-01-01
Previous studies have found that factors that improved assessment center (AC) construct related validity also had beneficial effects on criterion related validity. However some factors might have diverging effects on construct and criterion related validity. Accordingly we followed recent calls to evaluate construct and criterion related validity of ACs simultaneously by examining the effects of the factor exercise similarity on both aspects of validity within a single study. Data were coll...
General relativity with applications to astrophysics
Straumann, Norbert
2004-01-01
This text provides a comprehensive and timely introduction to general relativity The foundations of the theory in Part I are thoroughly developed together with the required mathematical background from differential geometry in Part III The six chapters in Part II are devoted to tests of general relativity and to many of its applications Binary pulsars are studied in considerable detail Much space is devoted to the study of compact objects, especially to black holes This includes a detailed derivation of the Kerr solution, Israel's proof of his uniqueness theorem, and derivations of the basic laws of black hole physics The final chapter of this part contains Witten's proof of the positive energy theorem The book addresses undergraduate and graduate students in physics, astrophysics and mathematics It is very well structured and should become a standard text for a modern treatment of gravitational physics The clear presentation of differential geometry makes it also useful for string theory and other fields of ...
Gravity An Introduction to Einstein's General Relativity
Hartle, James B
2003-01-01
The aim of this groundbreaking new book is to bring general relativity into the undergraduate curriculum and make this fundamental theory accessible to all physics majors. Using a "physics first" approach to the subject, renowned relativist James B. Hartle provides a fluent and accessible introduction that uses a minimum of new mathematics and is illustrated with a wealth of exciting applications. The emphasis is on the exciting phenomena of gravitational physics and the growing connection between theory and observation. The Global Positioning System, black holes, X-ray sources, pulsars, quasars, gravitational waves, the Big Bang, and the large scale structure of the universe are used to illustrate the widespread role of how general relativity describes a wealth of everyday and exotic phenomena.
Generalizing the spatial relative risk function.
Sarojinie Fernando, W T P; Hazelton, Martin L
2014-04-01
The spatial relative risk function is defined as the ratio of densities describing respectively the spatial distribution of cases and controls. It has proven to be an effective tool for visualizing spatial variation in risk in many epidemiological applications over the past 20 years. We discuss the generalization of this function to spatio-temporal case-control data, and also to situations where there are covariates available that may affect the spatial patterns of disease. We examine estimation of the generalized relative risk functions using kernel smoothing, including asymptotic theory and data-driven bandwidth selection. We also consider construction of tolerance contours. Our methods are illustrated on spatio-temporal data describing the 2001 outbreak of foot-and-mouth disease in the United Kingdom, with farm size as a covariate. Copyright © 2013 Elsevier Ltd. All rights reserved.
Solar system dynamics in general relativity
Battista, Emmanuele; Esposito, Giampiero; Di Fiore, Luciano; Simo, Jules; Grado, Aniello
2016-01-01
Recent work in the literature has advocated using the Earth-Moon-planetoid Lagrangian points as observables, in order to test general relativity and effective field theories of gravity in the solar system. However, since the three-body problem of classical celestial mechanics is just an approximation of a much more complicated setting, where all celestial bodies in the solar system are subject to their mutual gravitational interactions, while solar radiation pressure and other sources of nongravitational perturbations also affect the dynamics, it is conceptually desirable to improve the current understanding of solar system dynamics in general relativity, as a first step towards a more accurate theoretical study of orbital motion in the weak-gravity regime. For this purpose, starting from the Einstein equations in the de Donder-Lanczos gauge, this paper arrives first at the Levi-Civita Lagrangian for the geodesic motion of celestial bodies, showing in detail under which conditions the effects of internal stru...
Testing General Relativity with Pulsar Timing
Directory of Open Access Journals (Sweden)
Stairs Ingrid H.
2003-01-01
Full Text Available Pulsars of very different types, including isolated objects and binaries (with short- and long-period orbits, and white-dwarf and neutron-star companions provide the means to test both the predictions of general relativity and the viability of alternate theories of gravity. This article presents an overview of pulsars, then discusses the current status of and future prospects for tests of equivalence-principle violations and strong-field gravitational experiments.
Special relativity, electrodynamics, and general relativity from Newton to Einstein
Kogut, John B
2018-01-01
Special Relativity, Electrodynamics and General Relativity: From Newton to Einstein, Second Edition, is intended to teach (astro)physics, astronomy, and cosmology students how to think about special and general relativity in a fundamental, but accessible, way. Designed to render any reader a "master of relativity," everything on the subject is comprehensible and derivable from first principles. The book emphasizes problem solving, contains abundant problem sets, and is conveniently organized to meet the needs of both student and instructor. Fully revised, updated and expanded second edition Includes new chapters on magnetism as a consequence of relativity and electromagnetism Contains many improved and more engaging figures Uses less algebra resulting in more efficient derivations Enlarged discussion of dynamics and the relativistic version of Newton's second law
Relativity the special and the general theory
Einstein, Albert
2015-01-01
After completing the final version of his general theory of relativity in November 1915, Albert Einstein wrote a book about relativity for a popular audience. His intention was "to give an exact insight into the theory of relativity to those readers who, from a general scientific and philosophical point of view, are interested in the theory, but who are not conversant with the mathematical apparatus of theoretical physics." The book remains one of the most lucid explanations of the special and general theories ever written. In the early 1920s alone, it was translated into ten languages, and fifteen editions in the original German appeared over the course of Einstein's lifetime. This new edition of Einstein's celebrated book features an authoritative English translation of the text along with an introduction and a reading companion by Hanoch Gutfreund and Jürgen Renn that examines the evolution of Einstein's thinking and casts his ideas in a broader present-day context. A special chapter explores the history...
On solar system dynamics in general relativity
Battista, Emmanuele; Esposito, Giampiero; di Fiore, Luciano; Dell'Agnello, Simone; Simo, Jules; Grado, Aniello
Recent work in the literature has advocated using the Earth-Moon-planetoid Lagrangian points as observables, in order to test general relativity and effective field theories of gravity in the solar system. However, since the three-body problem of classical celestial mechanics is just an approximation of a much more complicated setting, where all celestial bodies in the solar system are subject to their mutual gravitational interactions, while solar radiation pressure and other sources of nongravitational perturbations also affect the dynamics, it is conceptually desirable to improve the current understanding of solar system dynamics in general relativity, as a first step towards a more accurate theoretical study of orbital motion in the weak-gravity regime. For this purpose, starting from the Einstein equations in the de Donder-Lanczos gauge, this paper arrives first at the Levi-Civita Lagrangian for the geodesic motion of planets, showing in detail under which conditions the effects of internal structure and finite extension get canceled in general relativity to first post-Newtonian order. The resulting nonlinear ordinary differential equations for the motion of planets and satellites are solved for the Earth’s orbit about the Sun, written down in detail for the Sun-Earth-Moon system, and investigated for the case of planar motion of a body immersed in the gravitational field produced by the other bodies (e.g. planets with their satellites). At this stage, we prove an exact property, according to which the fourth-order time derivative of the original system leads to a linear system of ordinary differential equations. This opens an interesting perspective on forthcoming research on planetary motions in general relativity within the solar system, although the resulting equations remain a challenge for numerical and qualitative studies. Last, the evaluation of quantum corrections to location of collinear and noncollinear Lagrangian points for the planar restricted
The construct validity of general and specific dimensions of personality pathology.
Williams, T F; Scalco, M D; Simms, L J
2017-08-22
Modern personality disorder (PD) theory and research attempt to distinguish transdiagnostic impairments common to all PDs from constructs that explain varied PD expression. Bifactor modeling tests such distinctions; however, the only published PD criteria bifactor analysis focused on only 6 PDs and did not examine the model's construct validity. We examined the structure and construct validity of competing PD criteria models using confirmatory and exploratory factor analytic methods in 628 patients who completed structured diagnostic interviews and self-reports of personality traits and impairment. Relative to alternative models, two bifactor models - one confirmatory model with 10 specific factors for each PD (acceptable fit) and one exploratory model with four specific factors resembling broad personality domains (excellent fit) - fit best and were compared via connections with external criteria. General and specific factors related meaningfully and differentially to personality traits, internalizing symptoms, substance use, and multiple indices of psychosocial impairment. As hypothesized, the general factor predicted interpersonal dysfunction above and beyond other psychopathology. The general factor also correlated strongly with many pathological personality traits. The present study supported the validity of a model with both a general PD impairment dimension and separate individual difference dimensions; however, it also indicated that currently prominent models, which assume general PD impairments and personality traits are non-overlapping, may be misspecified.
Premetric equivalent of general relativity: Teleparallelism
Itin, Yakov; Hehl, Friedrich W.; Obukhov, Yuri N.
2017-04-01
In general relativity (GR), the metric tensor of spacetime is essential since it represents the gravitational potential. In other gauge theories (such as electromagnetism), the so-called premetric approach succeeds in separating the purely topological field equation from the metric-dependent constitutive law. We show here that GR allows for a premetric formulation, too. For this purpose, we apply the teleparallel approach of gravity, which represents GR as a gauge theory based on the translation group. We formulate the metric-free topological field equation and a general linear constitutive law between the basic field variables. The requirement of local Lorentz invariance turns the model into a full equivalent of GR. Our approach opens a way for a natural extension of GR to diverse geometrical structures of spacetime.
General Relativity As an Aether Theory
Dupre, Maurice J
2010-01-01
Most early twentieth century relativists --- Lorentz, Einstein, Eddington, for examples --- claimed that general relativity was merely a theory of the aether. We shall confirm this claim by deriving the Einstein equations using aether theory. We shall use a combination of Lorentz's and Kelvin's conception of the aether. Our derivation of the Einstein equations will not use the vanishing of the covariant divergence of the stress-energy tensor, but instead equate the Ricci tensor to the sum of the usual stress-energy tensor and a stress-energy tensor for the aether, a tensor based on Kelvin's aether theory. A crucial first step is generalizing the Cartan formalism of Newtonian gravity to allow spatial curvature, as conjectured by Gauss and Riemann.
Point massive particle in General Relativity
Katanaev, M. O.
2013-10-01
It is well known that the Schwarzschild solution describes the gravitational field outside compact spherically symmetric mass distribution in General Relativity. In particular, it describes the gravitational field outside a point particle. Nevertheless, what is the exact solution of Einstein's equations with -type source corresponding to a point particle is not known. In the present paper, we prove that the Schwarzschild solution in isotropic coordinates is the asymptotically flat static spherically symmetric solution of Einstein's equations with -type energy-momentum tensor corresponding to a point particle. Solution of Einstein's equations is understood in the generalized sense after integration with a test function. Metric components are locally integrable functions for which nonlinear Einstein's equations are mathematically defined. The Schwarzschild solution in isotropic coordinates is locally isometric to the Schwarzschild solution in Schwarzschild coordinates but differs essentially globally. It is topologically trivial neglecting the world line of a point particle. Gravity attraction at large distances is replaced by repulsion at the particle neighborhood.
Verification and Validation of the General Mission Analysis Tool (GMAT)
Hughes, Steven P.; Qureshi, Rizwan H.; Cooley, D. Steven; Parker, Joel J. K.; Grubb, Thomas G.
2014-01-01
This paper describes the processes and results of Verification and Validation (V&V) efforts for the General Mission Analysis Tool (GMAT). We describe the test program and environments, the tools used for independent test data, and comparison results. The V&V effort produced approximately 13,000 test scripts that are run as part of the nightly buildtest process. In addition, we created approximately 3000 automated GUI tests that are run every two weeks. Presenting all test results are beyond the scope of a single paper. Here we present high-level test results in most areas, and detailed test results for key areas. The final product of the V&V effort presented in this paper was GMAT version R2013a, the first Gold release of the software with completely updated documentation and greatly improved quality. Release R2013a was the staging release for flight qualification performed at Goddard Space Flight Center (GSFC) ultimately resulting in GMAT version R2013b.
Numerical Hydrodynamics and Magnetohydrodynamics in General Relativity
Directory of Open Access Journals (Sweden)
Font José A.
2008-09-01
Full Text Available This article presents a comprehensive overview of numerical hydrodynamics and magnetohydrodynamics (MHD in general relativity. Some significant additions have been incorporated with respect to the previous two versions of this review (2000, 2003, most notably the coverage of general-relativistic MHD, a field in which remarkable activity and progress has occurred in the last few years. Correspondingly, the discussion of astrophysical simulations in general-relativistic hydrodynamics is enlarged to account for recent relevant advances, while those dealing with general-relativistic MHD are amply covered in this review for the first time. The basic outline of this article is nevertheless similar to its earlier versions, save for the addition of MHD-related issues throughout. Hence, different formulations of both the hydrodynamics and MHD equations are presented, with special mention of conservative and hyperbolic formulations well adapted to advanced numerical methods. A large sample of numerical approaches for solving such hyperbolic systems of equations is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. As previously stated, a comprehensive summary of astrophysical simulations in strong gravitational fields is also presented. These are detailed in three basic sections, namely gravitational collapse, black-hole accretion, and neutron-star evolutions; despite the boundaries, these sections may (and in fact do overlap throughout the discussion. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances in the formulation of the gravitational field, hydrodynamics and MHD equations and the numerical methodology designed to solve them. To keep the length of this article reasonable
Numerical Hydrodynamics and Magnetohydrodynamics in General Relativity.
Font, José A
2008-01-01
This article presents a comprehensive overview of numerical hydrodynamics and magneto-hydrodynamics (MHD) in general relativity. Some significant additions have been incorporated with respect to the previous two versions of this review (2000, 2003), most notably the coverage of general-relativistic MHD, a field in which remarkable activity and progress has occurred in the last few years. Correspondingly, the discussion of astrophysical simulations in general-relativistic hydrodynamics is enlarged to account for recent relevant advances, while those dealing with general-relativistic MHD are amply covered in this review for the first time. The basic outline of this article is nevertheless similar to its earlier versions, save for the addition of MHD-related issues throughout. Hence, different formulations of both the hydrodynamics and MHD equations are presented, with special mention of conservative and hyperbolic formulations well adapted to advanced numerical methods. A large sample of numerical approaches for solving such hyperbolic systems of equations is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. As previously stated, a comprehensive summary of astrophysical simulations in strong gravitational fields is also presented. These are detailed in three basic sections, namely gravitational collapse, black-hole accretion, and neutron-star evolutions; despite the boundaries, these sections may (and in fact do) overlap throughout the discussion. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances in the formulation of the gravitational field, hydrodynamics and MHD equations and the numerical methodology designed to solve them. To keep the length of this article reasonable, an effort has
Relation of validation experiments to applications.
Energy Technology Data Exchange (ETDEWEB)
Hamilton, James R. (New Mexico State University, Las Cruces, NM); Hills, Richard Guy
2009-02-01
Computational and mathematical models are developed in engineering to represent the behavior of physical systems to various system inputs and conditions. These models are often used to predict at other conditions, rather than to just reproduce the behavior of data obtained at the experimental conditions. For example, the boundary or initial conditions, time of prediction, geometry, material properties, and other model parameters can be different at test conditions than those for an anticipated application of a model. Situations for which the conditions may differ include those for which (1) one is in the design phase and a prototype of the system has not been constructed and tested under the anticipated conditions, (2) only one version of a final system can be built and destructive testing is not feasible, or (3) the anticipated design conditions are variable and one cannot easily reproduce the range of conditions with a limited number of carefully controlled experiments. Because data from these supporting experiments have value in model validation, even if the model was tested at different conditions than an anticipated application, methodology is required to evaluate the ability of the validation experiments to resolve the critical behavior for the anticipated application. The methodology presented uses models for the validation experiments and a model for the application to address how well the validation experiments resolve the application. More specifically, the methodology investigates the tradeoff that exists between the uncertainty (variability) in the behavior of the resolved critical variables for the anticipated application and the ability of the validation experiments to resolve this behavior. The important features of this approach are demonstrated through simple linear and non-linear heat conduction examples.
General Election 2004: Empirical Validation of Voting Pattern in Malaysia
Directory of Open Access Journals (Sweden)
Syed Arabi Idid
2007-06-01
Full Text Available Abstract: The purpose of this study is to test the effects of the politically related socio-economic issues, personality of the new Prime Minister and the perceived strength of the ruling party, Barisan Nasional (BN, in influencing the outcomes of elections. It uses the data from the Star-IIUM Survey 2004 and the official election results of general election 2004 for the three northern states of Malaysia and applies the Structural Equation Modeling (SEM. The study found that the personal attributes of the Prime Minister, the strength of the ruling party and the campaign issues positively influenced the popular votes secured by the BN candidates.
The mathematical theory of general relativity
Katkar, L N
2014-01-01
This book is prepared for M. Sc. Students of Mathematics and Physics. The aim of writing this book is to give the reader a feeling for the necessity and beauty of the laws of general relativity. The contents of the book will attract both mathematicians and physicists which provides motivation and applications of many ideas and powerful mathematical methods of modern analysis and differential geometry. An attempt has been made to make the presentation comprehensive, rigorous and yet simple. Most calculations and transformations have been carried out in great detail. KEY FEATURE: Numerous solved examples using the well known mathematical techniques viz., the tensors and the differential forms in each chapter.
Modelling of general relativity phenomena with photonics
Fernández Núñez, Isabel Dèlia
2014-01-01
Treball final de màster oficial fet en col·laboració amb Universitat Autònoma de Barcelona (UAB), Universitat de Barcelona (UB) i Institut de Ciències Fotòniques (ICFO) [ANGLÈS] Metamaterials are man-made artificial materials whose electromagnetic parameters the permittivity and permeability are determined by its internal structure rather than their substance. An analogy between the electrodynamics of these new materials and general relativity is discussed. Based on this analogy, the possi...
Time asymmetric extensions of general relativity
Cortes, Marina; Smolin, Lee
2015-01-01
We describe a class of modified gravity theories that deform general relativity in a way that breaks time reversal invariance and, very mildly, locality. The algebra of constraints, local physical degrees of freedom, and their linearized equations of motion, are unchanged, yet observable effects may be present on cosmological scales, which have implications for the early history of the universe. This is achieved in the Hamiltonian framework, in a way that requires the constant mean curvature gauge conditions and is, hence, inspired by shape dynamics.
100 Years of General Theory of Relativity
2015-01-01
The Symposium will celebrate the 100th anniversary of Einstein's four papers on General Relativity, which he submitted to the Preussische Akademie der Wissenschaften during November 1915. A review of the history of the creation of Einstein's masterpiece, from its roots in Bern, the important steps forward in Zurich and up to its completion in Berlin will be followed by an extensive overview covering the later developments up to present-day research. This will include discussions on the impact of the theory on our view of the universe as well as on progress in technology for everyday life.
New Area Law in General Relativity.
Bousso, Raphael; Engelhardt, Netta
2015-08-21
We report a new area law in general relativity. A future holographic screen is a hypersurface foliated by marginally trapped surfaces. We show that their area increases monotonically along the foliation. Future holographic screens can easily be found in collapsing stars and near a big crunch. Past holographic screens exist in any expanding universe and obey a similar theorem, yielding the first rigorous area law in big bang cosmology. Unlike event horizons, these objects can be identified at finite time and without reference to an asymptotic boundary. The Bousso bound is not used, but it naturally suggests a thermodynamic interpretation of our result.
On the validity and generality of transfer effects in cognitive training research.
Noack, Hannes; Lövdén, Martin; Schmiedek, Florian
2014-11-01
Evaluation of training effectiveness is a long-standing problem of cognitive intervention research. The interpretation of transfer effects needs to meet two criteria, generality and specificity. We introduce each of the two, and suggest ways of implementing them. First, the scope of the construct of interest (e.g., working memory) defines the expected generality of transfer effects. Given that the constructs of interest are typically defined at the latent level, data analysis should also be conducted at the latent level. Second, transfer should be restricted to measures that are theoretically related to the trained construct. Hence, the construct of interest also determines the specificity of expected training effects; to test for specificity, study designs should aim at convergent and discriminant validity. We evaluate the recent cognitive training literature in relation to both criteria. We conclude that most studies do not use latent factors for transfer assessment, and do not test for convergent and discriminant validity.
Introduction to general relativity and cosmology
Berger, Mitchell A
2018-01-01
The textbook aims to present general relativity and modern cosmology in a friendly form suitable for advanced undergraduates. The text begins with a self-contained introduction to the theory of manifolds and then develops the tools needed to understand curved spaces and curved spacetimes. Special relativity can then be understood in a geometrical context, bypassing some of the difficulties students have when encountering relativistic effects (e.g. time dilation and length contraction) for the first time. The theory of curvature and its effects leads to the Einstein field equations and its classic tests in the precession of Mercury and the deflection of starlight. The second part of the book covers modern cosmology, starting with the evolution equations for the expansion of the universe. The microwave background, evidence for dark matter, and the clustering of galaxies are examined in detail.
41 CFR 60-3.5 - General standards for validity studies.
2010-07-01
... satisfying these guidelines, users may rely upon criterion-related validity studies, content validity studies... criterion-related validity study should consist of empirical data demonstrating that the selection procedure... validity studies. 60-3.5 Section 60-3.5 Public Contracts and Property Management Other Provisions Relating...
The validity of peer review in a general medicine journal.
Directory of Open Access Journals (Sweden)
Jeffrey L Jackson
Full Text Available UNLABELLED: All the opinions in this article are those of the authors and should not be construed to reflect, in any way, those of the Department of Veterans Affairs. BACKGROUND: Our study purpose was to assess the predictive validity of reviewer quality ratings and editorial decisions in a general medicine journal. METHODS: Submissions to the Journal of General Internal Medicine (JGIM between July 2004 and June 2005 were included. We abstracted JGIM peer review quality ratings, verified the publication status of all articles and calculated an impact factor for published articles (Rw by dividing the 3-year citation rate by the average for this group of papers; an Rw>1 indicates a greater than average impact. RESULTS: Of 507 submissions, 128 (25% were published in JGIM, 331 rejected (128 with review and 48 were either not resubmitted after revision was requested or were withdrawn by the author. Of 331 rejections, 243 were published elsewhere. Articles published in JGIM had a higher citation rate than those published elsewhere (Rw: 1.6 vs. 1.1, p = 0.002. Reviewer quality ratings of article quality had good internal consistency and reviewer recommendations markedly influenced publication decisions. There was no quality rating cutpoint that accurately distinguished high from low impact articles. There was a stepwise increase in Rw for articles rejected without review, rejected after review or accepted by JGIM (Rw 0.60 vs. 0.87 vs. 1.56, p<0.0005. However, there was low agreement between reviewers for quality ratings and publication recommendations. The editorial publication decision accurately discriminated high and low impact articles in 68% of submissions. We found evidence of better accuracy with a greater number of reviewers. CONCLUSIONS: The peer review process largely succeeds in selecting high impact articles and dispatching lower impact ones, but the process is far from perfect. While the inter-rater reliability between individual
Validation of an instrument to measure inter-organisational linkages in general practice
Directory of Open Access Journals (Sweden)
Cheryl Amoroso
2007-11-01
Full Text Available Purpose: Linkages between general medical practices and external services are important for high quality chronic disease care. The purpose of this research is to describe the development, evaluation and use of a brief tool that measures the comprehensiveness and quality of a general practice’s linkages with external providers for the management of patients with chronic disease. In this study, clinical linkages are defined as the communication, support, and referral arrangements between services for the care and assistance of patients with chronic disease. Methods: An interview to measure surgery-level (rather than individual clinician-level clinical linkages was developed, piloted, reviewed, and evaluated with 97 Australian general practices. Two validated survey instruments were posted to patients, and a survey of locally available services was developed and posted to participating Divisions of General Practice (support organisations. Hypotheses regarding internal validity, association with local services, and patient satisfaction were tested using factor analysis, logistic regression and multilevel regression models. Results: The resulting General Practice Clinical Linkages Interview (GP-CLI is a nine-item tool with three underlying factors: referral and advice linkages, shared care and care planning linkages, and community access and awareness linkages. Local availability of chronic disease services has no affect on the comprehensiveness of services with which practices link, however comprehensiveness of clinical linkages has an association with patient assessment of access, receptionist services, and of continuity of care in their general practice. Conclusions: The GP-CLI may be useful to researchers examining comparable health care systems for measuring the comprehensiveness and quality of linkages at a general practice-level with related services, possessing both internal and external validity. The tool can be used with large samples
Von Neumann's quantization of general relativity
Arbuzov, A. B.; Cherny, A. Yu.; Cirilo-Lombardo, D. J.; Nazmitdinov, R. G.; Han, Nguyen Suan; Pavlov, A. E.; Pervushin, V. N.; Zakharov, A. F.
2017-05-01
Von Neumann's procedure is applied to quantizing general relativity. Initial data for dynamical variables in the Planck epoch, where the Hubble parameter value coincided with the Planck mass are quantized. These initial data are defined in terms of the Fock orthogonal simplex in the tangent Minkowski spacetime and the Dirac conformal interval. The Einstein cosmological principle is used to average the logarithm of the determinant of the spatial metric over the spatial volume of the visible Universe. The splitting of general coordinate transformations into diffeomorphisms and transformations of the initial data is introduced. In accordance with von Neumann's procedure, the vacuum state is treated is a quantum ensemble that is degenerate in quantum numbers of nonvacuum states. The distribution of the vacuum state leads to the Casimir effect in gravidynamics in just the same way as in electrodynamics. The generating functional for perturbation theory in gravidynamics is found by solving the quantum energy constraint. The applicability range of gravidynamics is discussed along with the possibility of employing this theory to interpret modern observational data.
The confrontation between general relativity and experiment
Will, C. M.
1980-01-01
Experiments that test the foundations of gravitation theory in terms of the Einstein equivalence principle are discussed along with solar system tests of general relativity at the post-Newtonian level. These include classical (light-deflection, time delay and perihelion shift) tests as well as tests of the strong equivalence principle. The binary pulsar is discussed as an extra-solar-system gravitational testing ground, and attention is given to the multipolarity of the waves and the amount of radiation damping. The mass function, periastron shift, redshift-Doppler parameter and rate of change of the orbit period (Pb) of the binary pulsar are also considered, and it is suggested that the measurement of Pb represents the first observation of the effects of gravitational radiation.
Motivations for antigravity in General Relativity
Chardin, G.
1997-08-01
We present arguments showing that it is natural to interpret the negative mass part of the Kerr solution as representing the geometry experienced by antimatter. The C, P and T discrete transformations are considered for this geometry. The C and T properties of the proposed identification are found to be in agreement with the usual representation of antimatter. In addition, we conjecture a property of perfect stigmatism through Kerr wormholes which allows General Relativity to mimic antigravity. Kerr wormholes would then act as “supermirrors” reversing the C, P and T images of an object seen through it. This interpretation is subject to several experimental tests and able to provide an explanation, without any free parameter, of the “CP” violation observed in the neutral kaon system.
Motivations for antigravity in General Relativity
Energy Technology Data Exchange (ETDEWEB)
Chardin, G. [DSM/DAPNIA/SPP, CEN-Saclay (France)
1997-08-15
We present arguments showing that it is natural to interpret the negative mass part of the Kerr solution as representing the geometry experienced by antimatter. The C, P and T discrete transformations are considered for this geometry. The C and T properties of the proposed identification are found to be in agreement with the usual representation of antimatter. In addition, we conjecture a property of perfect stigmatism through Kerr wormholes which allows General Relativity to mimic antigravity. Kerr wormholes would then act as 'supermirrors' reversing the C, P and T images of an object seen through it. This interpretation is subject to several experimental tests and able to provide an explanation, without any free parameter, of the 'CP' violation observed in the neutral kaon system.
On thick domain walls in general relativity
Goetz, Guenter; Noetzold, Dirk
1989-01-01
Planar scalar field configurations in general relativity differ considerably from those in flat space. It is shown that static domain walls of finite thickness in curved space-time do not possess a reflection symmetry. At infinity, the space-time tends to the Taub vacuum on one side of the wall and to the Minkowski vacuum (Rindler space-time) on the other. Massive test particles are always accelerated towards the Minkowski side, i.e., domain walls are attractive on the Taub side, but repulsive on the Minkowski side (Taub-vacuum cleaner). It is also proved that the pressure in all directions is always negative. Finally, a brief comment is made concerning the possibility of infinite, i.e., bigger than horizon size, domain walls in our universe. All of the results are independent of the form of the potential V(phi) greater than or equal to 0 of the scalar field phi.
Criterion-Related Validity of the PDD Behavior Inventory.
Cohen, Ira L.
2003-01-01
This study assessed the criterion-related validity of the PDD Behavior Inventory, a rating scale to evaluate the adaptive and maladaptive behaviors of children with pervasive developmental disorders. Good correlations with five other scales confirmed the scale's validity and suggest its value in assessing treatment-related changes in maladaptive…
An Introduction to General Relativity and Cosmology
Plebanski, Jerzy; Krasinski, Andrzej
2012-09-01
1. How the theory of relativity came into being (a brief historical sketch); Part I. Elements of Differential Geometry: 2. A short sketch of two-dimensional differential geometries; 3. Tensors, tensor densities; 4. Covariant derivatives; 5. Parallel transport and geodesic lines; 6. Curvature of a manifold: flat manifolds; 7. Riemannian geometry; 8. Symmetries of Rieman spaces, invariance of tensors; 9. Methods to calculate the curvature quickly - Cartan forms and algebraic computer programs; 10. The spatially homogeneous Bianchi-type spacetimes; 11. The Petrov classification by the spinor method; Part II. The Gravitation Theory: 12. The Einstein equations and the sources of a gravitational field; 13. The Maxwell and Einstein-Maxwell equations and the Kaluza-Klein theory; 14. Spherically symmetric gravitational field of isolated objects; 15. Relativistic hydrodynamics and thermodynamics; 16. Relativistic cosmology I: general geometry; 17. Relativistic cosmology II: the Robertson-Walker geometry; 18. Relativistic cosmology III: the Lemaître-Tolman geometry; 19. Relativistic cosmology IV: generalisations of L-T and related geometries; 20. The Kerr solution; 21. Subjects omitted in this book; References.
BOOK REVIEW: Modern Canonical Quantum General Relativity
Kiefer, Claus
2008-06-01
The open problem of constructing a consistent and experimentally tested quantum theory of the gravitational field has its place at the heart of fundamental physics. The main approaches can be roughly divided into two classes: either one seeks a unified quantum framework of all interactions or one starts with a direct quantization of general relativity. In the first class, string theory (M-theory) is the only known example. In the second class, one can make an additional methodological distinction: while covariant approaches such as path-integral quantization use the four-dimensional metric as an essential ingredient of their formalism, canonical approaches start with a foliation of spacetime into spacelike hypersurfaces in order to arrive at a Hamiltonian formulation. The present book is devoted to one of the canonical approaches—loop quantum gravity. It is named modern canonical quantum general relativity by the author because it uses connections and holonomies as central variables, which are analogous to the variables used in Yang Mills theories. In fact, the canonically conjugate variables are a holonomy of a connection and the flux of a non-Abelian electric field. This has to be contrasted with the older geometrodynamical approach in which the metric of three-dimensional space and the second fundamental form are the fundamental entities, an approach which is still actively being pursued. It is the author's ambition to present loop quantum gravity in a way in which every step is formulated in a mathematically rigorous form. In his own words: 'loop quantum gravity is an attempt to construct a mathematically rigorous, background-independent, non-perturbative quantum field theory of Lorentzian general relativity and all known matter in four spacetime dimensions, not more and not less'. The formal Leitmotiv of loop quantum gravity is background independence. Non-gravitational theories are usually quantized on a given non-dynamical background. In contrast, due to
AB INITIO PULSAR MAGNETOSPHERE: THE ROLE OF GENERAL RELATIVITY
Energy Technology Data Exchange (ETDEWEB)
Philippov, Alexander A.; Cerutti, Benoit; Spitkovsky, Anatoly [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08544 (United States); Tchekhovskoy, Alexander, E-mail: sashaph@princeton.edu [Departments of Physics and Astronomy, University of California, Berkeley, CA 94720 (United States)
2015-12-20
It has recently been demonstrated that self-consistent particle-in-cell simulations of low-obliquity pulsar magnetospheres in flat spacetime show weak particle acceleration and no pair production near the poles. We investigate the validity of this conclusion in a more realistic spacetime geometry via general-relativistic particle-in-cell simulations of the aligned pulsar magnetosphere with pair formation. We find that the addition of the frame-dragging effect makes the local current density along the magnetic field larger than the Goldreich–Julian value, which leads to unscreened parallel electric fields and the ignition of a pair cascade. When pair production is active, we observe field oscillations in the open field bundle, which could be related to pulsar radio emission. We conclude that general-relativistic effects are essential for the existence of the pulsar mechanism in low-obliquity rotators.
Statistical validation of earthquake related observations
Kossobokov, V. G.
2011-12-01
The confirmed fractal nature of earthquakes and their distribution in space and time implies that many traditional estimations of seismic hazard (from term-less to short-term ones) are usually based on erroneous assumptions of easy tractable or, conversely, delicately-designed models. The widespread practice of deceptive modeling considered as a "reasonable proxy" of the natural seismic process leads to seismic hazard assessment of unknown quality, which errors propagate non-linearly into inflicted estimates of risk and, eventually, into unexpected societal losses of unacceptable level. The studies aimed at forecast/prediction of earthquakes must include validation in the retro- (at least) and, eventually, in prospective tests. In the absence of such control a suggested "precursor/signal" remains a "candidate", which link to target seismic event is a model assumption. Predicting in advance is the only decisive test of forecast/predictions and, therefore, the score-card of any "established precursor/signal" represented by the empirical probabilities of alarms and failures-to-predict achieved in prospective testing must prove statistical significance rejecting the null-hypothesis of random coincidental occurrence in advance target earthquakes. We reiterate suggesting so-called "Seismic Roulette" null-hypothesis as the most adequate undisturbed random alternative accounting for the empirical spatial distribution of earthquakes: (i) Consider a roulette wheel with as many sectors as the number of earthquake locations from a sample catalog representing seismic locus, a sector per each location and (ii) make your bet according to prediction (i.e., determine, which locations are inside area of alarm, and put one chip in each of the corresponding sectors); (iii) Nature turns the wheel; (iv) accumulate statistics of wins and losses along with the number of chips spent. If a precursor in charge of prediction exposes an imperfection of Seismic Roulette then, having in mind
General relativity in hyperextended chaotic inflation
Susperregi, M
1999-01-01
We address the question of whether general relativity (GR) is an 'attractor' in a universe governed by hyperextended chaotic inflation (HCI). HCI results from the combination of chaotic inflation and a theory of gravity that is equivalent to Brans-Dicke (BD) gravity within the horizon scale. Globally it differs from BD gravity in that omega is a dynamical parameter that depends on the BD field PHI. As is well known, GR is recovered from BD gravity in the limit omega -> infinity and large values of PHI. A substantial difficulty in studying HCI is to find and adequate model for the functional dependence of omega. In this paper we employ the analogy between the BD field in HCI and the dilaton field in string theory to construct an ansatz for omega(PHI). The string theory analogy is based on the principle of least coupling of Polyakov and Damour which states that the dilaton and metric fields decouple asymptotically. Based on this principle, we investigate the question of whether a large value of omega is predomi...
Particle Pair Production in Cosmological General Relativity
Oliveira, Firmin J
2012-01-01
The Cosmological General Relativity of Carmeli, a 5-dimensional theory of time, space and velocity, predicts the existence of an acceleration $a_0 = c / \\tau$ due to the expansion of the universe, where $c$ is the speed of light in vacuum, $\\tau = 1/h$ is the Hubble-Carmeli time constant, where $h$ is the Hubble constant at zero distance and no gravity. The Carmeli force on a particle of mass $m$ is $F_c = m a_0$, a fifth force in nature. The fields resulting from the solution of the Einstein field equations in 5-D CGR and the Carmeli force are used to hypothesize the production of a particle and its antiparticle. The mass of each particle is found to be $m=\\tau c^3 / 4 G$, where $G$ is Newton's constant. The vacuum mass density derived from the physics is $\\rho_{vac} = -3/8 \\pi G \\tau^2$. The cosmological constant is then given by $\\Lambda = 3 / \\tau^2$. We derive an expression for $\\tau$ given by $\\tau = \\sqrt{(45 \\zeta (1 - g) c^3 \\hbar^3) / (4\\pi^3 G \\mu \\alpha^2 k^3 \\beta^3 T^3)}$, where $\\zeta$ is the b...
Longitudinal validation of general and specific structural features of personality pathology.
Wright, Aidan G C; Hopwood, Christopher J; Skodol, Andrew E; Morey, Leslie C
2016-11-01
Theorists have long argued that personality disorder (PD) is best understood in terms of general impairments shared across the disorders as well as more specific instantiations of pathology. A model based on this theoretical structure was proposed as part of the DSM-5 revision process. However, only recently has this structure been subjected to formal quantitative evaluation, with little in the way of validation efforts via external correlates or prospective longitudinal prediction. We used the Collaborative Longitudinal Study of Personality Disorders dataset to: (a) estimate structural models that parse general from specific variance in personality disorder features, (b) examine patterns of growth in general and specific features over the course of 10 years, and (c) establish concurrent and dynamic longitudinal associations in PD features and a host of external validators including basic personality traits and psychosocial functioning scales. We found that general PD exhibited much lower absolute stability and was most strongly related to broad markers of psychosocial functioning, concurrently and longitudinally, whereas specific features had much higher mean stability and exhibited more circumscribed associations with functioning. However, both general and specific factors showed recognizable associations with normative and pathological traits. These results can inform efforts to refine the conceptualization and diagnosis of personality pathology. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Directory of Open Access Journals (Sweden)
Masako Nishiwaki
2017-01-01
Full Text Available Acupuncture sensations are considered essential in producing the treatment effect of acupuncture. The Massachusetts General Hospital Acupuncture Sensation Scale (MASS is a frequently used scale in acupuncture research to measure acupuncture sensations. We translated the MASS into Japanese (Japanese MASS based on Beaton’s guidelines. 30 acupuncturists evaluated the relevancy and meaning of the 12 descriptors included in the Japanese MASS. The content validity ratios for 10 of the 12 descriptors were 0.33 or greater. 42 healthy subjects then evaluated acupuncture sensations evoked by manual acupuncture at LI4 using the Japanese MASS. Cronbach’s alpha was 0.86. The correlation coefficient of total MASS scores and total Short Form McGill Pain Questionnaire scores and MASS indices and sensory visual analogue scores were 0.78 and 0.80, respectively. Factor analysis loaded the 12 descriptors onto two meaningful factors. This study demonstrated that the Japanese MASS has good reliability, content validity, criterion-related validity, and construct validity. Therefore, the Japanese MASS is a valid and reliable instrument for use with Japanese populations.
Gamma and Related Functions Generalized for Sequences
Ollerton, R. L.
2008-01-01
Given a sequence g[subscript k] greater than 0, the "g-factorial" product [big product][superscript k] [subscript i=1] g[subscript i] is extended from integer k to real x by generalizing properties of the gamma function [Gamma](x). The Euler-Mascheroni constant [gamma] and the beta and zeta functions are also generalized. Specific examples include…
Development and initial validity of the Object Relations Rating Scale.
Diguer, Louis; Gamache, Dominick; Laverdière, Olivier
2012-01-01
The aim of this study was to report on the development and the initial validation of the Object Relations Rating Scale (ORRS), which is a measure of in-session enactments of object relations that draws on a psychodynamic conceptualization of personality organization. Forty participants were included in the study, distributed among neurotic, borderline and psychotic personality organizations (PO). Results showed that the interrater reliability of this new measure is good. Two tests of criterion validity support the validity of the measure: the ORRS discriminates well between the three PO groups and it correlates in expected ways with five PO dimensions. Finally, ORRS scales that pertain to the degree of in-session object relation enactments correlated with a measure of transference intensity (convergent validity), and correlations with therapists experience were low as expected (discriminant validity).
Gravitational Wave in Linear General Relativity
Cubillos, D. J.
2017-07-01
General relativity is the best theory currently available to describe the interaction due to gravity. Within Albert Einstein's field equations this interaction is described by means of the spatiotemporal curvature generated by the matter-energy content in the universe. Weyl worked on the existence of perturbations of the curvature of space-time that propagate at the speed of light, which are known as Gravitational Waves, obtained to a first approximation through the linearization of the field equations of Einstein. Weyl's solution consists of taking the field equations in a vacuum and disturbing the metric, using the Minkowski metric slightly perturbed by a factor ɛ greater than zero but much smaller than one. If the feedback effect of the field is neglected, it can be considered as a weak field solution. After introducing the disturbed metric and ignoring ɛ terms of order greater than one, we can find the linearized field equations in terms of the perturbation, which can then be expressed in terms of the Dalambertian operator of the perturbation equalized to zero. This is analogous to the linear wave equation in classical mechanics, which can be interpreted by saying that gravitational effects propagate as waves at the speed of light. In addition to this, by studying the motion of a particle affected by this perturbation through the geodesic equation can show the transversal character of the gravitational wave and its two possible states of polarization. It can be shown that the energy carried by the wave is of the order of 1/c5 where c is the speed of light, which explains that its effects on matter are very small and very difficult to detect.
Content validity and reliability of the Copenhagen social relations questionnaire
DEFF Research Database (Denmark)
Lund, Rikke; Nielsen, Lene Snabe; Henriksen, Pia Wichmann
2014-01-01
OBJECTIVE: The aim of the present article is to describe the face and content validity as well as reliability of the Copenhagen Social Relations Questionnaire (CSRQ). METHOD: The face and content validity test was based on focus group discussions and individual interviews with 31 informants...
General Information about AIDS-Related Lymphoma
... spreading to the central nervous system (CNS). For treatment, AIDS-related lymphomas are grouped based on where they ... only to patients who have not started treatment. Treatment of AIDS-related lymphoma combines treatment of the lymphoma with ...
The Development and Validation of a Measure of Relational Leadership.
Carifio, James; Eyemaro, Bennie
This study reports the development and validation of the Relational Leadership Questionnaire (RLQ). The consensus attributes of relational leadership are that the relational leader is caring, empowering, ethical, inclusive, and has vision. For each of these five attributes, 10 Likert items were written using a 7-point response scale. These 50…
The New Aspects of General Relativity
Rabounski, D
2004-01-01
The study represents developments of A. L. Zelmanov's mathematical apparatus of chronometric invariants (physical observable values in General Relaivity), defined as the projections of four-dimensional values on time lines and the spatial section. Employing the mathematical methods gives new directions in the theory of fields.
Matroidal Structure of Generalized Rough Sets Based on Tolerance Relations
Directory of Open Access Journals (Sweden)
Hui Li
2014-01-01
of the generalized rough set based on the tolerance relation. The matroid can also induce a new relation. We investigate the connection between the original tolerance relation and the induced relation.
The confrontation between general relativity and experiment
Indian Academy of Sciences (India)
The best tests of local Lorentz invariance are the 'mass anisotropy' or 'Hughes–. Drever' experiments. A simple way of interpreting these experiments is to suppose that a non-metric coupling to the electromagnetic interactions results in a change in the speed of electromagnetic radiation c relative to the limiting speed of the.
2011-01-25
... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Guidance for Industry on Process Validation: General Principles and Practices; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY...
Endocrine Disruptor Screening Program (EDSP) Universe of Chemicals and General Validation Principles
This document was developed by the EPA to provide guidance to staff and managers regarding the EDSP universe of chemicals and general validation principles for consideration of computational toxicology tools for chemical prioritization.
Fundamental optimal relation of a generalized irreversible Carnot ...
Indian Academy of Sciences (India)
Abstract. The fundamental optimal relation between heating load and coefficient of performance (COP) of a generalized irreversible Carnot heat pump is derived based on a new generalized heat transfer law, which includes the generalized convective heat transfer law and generalized radiative heat transfer law, ...
Fok, Marcella Lei-Yee; Seegobin, Seth; Frissa, Souci; Hatch, Stephani L; Hotopf, Matthew; Hayes, Richard D; Moran, Paul
2015-11-01
Personality disorder (PD) is associated with important health outcomes in the general population. However, the length of diagnostic interviews poses a significant barrier to obtaining large scale, population-based data on PD. A brief screen for the identification of people at high risk of PD in the general population could be extremely valuable for both clinicians and researchers. We set out to validate the Standardised Assessment of Personality - Abbreviated Scale (SAPAS), in a general population sample, using the Structured Clinical Interviews for DSM-IV Personality Disorders (SCID-II) as a gold standard. One hundred and ten randomly selected, community-dwelling adults were administered the SAPAS screening interview. The SCID-II was subsequently administered by a clinical interviewer blind to the initial SAPAS score. Receiver operating characteristic analysis was used to assess the discriminatory performance of the SAPAS, relative to the SCID-II. Area under the curve for the SAPAS was 0.70 (95% CI = 0.60 to 0.80; p < 0.001), indicating moderate overall discriminatory accuracy. A cut point score of 4 on the SAPAS correctly classified 58% of participants. At this cut point, the sensitivity and specificity were 0.69 and 0.53 respectively. The SAPAS operates less efficiently as a screen in general population samples and is probably most usefully applied in clinical populations. © 2015 The Authors Personality and Mental Health published by John Wiley & Sons Ltd.
BOOK REVIEW: Advanced Mechanics and General Relativity Advanced Mechanics and General Relativity
Louko, Jorma
2011-04-01
Joel Franklin's textbook `Advanced Mechanics and General Relativity' comprises two partially overlapping, partially complementary introductory paths into general relativity at advanced undergraduate level. Path I starts with the Lagrangian and Hamiltonian formulations of Newtonian point particle motion, emphasising the action principle and the connection between symmetries and conservation laws. The concepts are then adapted to point particle motion in Minkowski space, introducing Lorentz transformations as symmetries of the action. There follows a focused development of tensor calculus, parallel transport and curvature, using examples from Newtonian mechanics and special relativity, culminating in the field equations of general relativity. The Schwarzschild solution is analysed, including a detailed discussion of the tidal forces on a radially infalling observer. Basics of gravitational radiation are examined, highlighting the similarities to and differences from electromagnetic radiation. The final topics in Path I are equatorial geodesics in Kerr and the motion of a relativistic string in Minkowski space. Path II starts by introducing scalar field theory on Minkowski space as a limit of point masses connected by springs, emphasising the action principle, conservation laws and the energy-momentum tensor. The action principle for electromagnetism is introduced, and the coupling of electromagnetism to a complex scalar field is developed in a detailed and pedagogical fashion. A free symmetric second-rank tensor field on Minkowski space is introduced, and the action principle of general relativity is recovered from coupling the second-rank tensor to its own energy-momentum tensor. Path II then merges with Path I and, supplanted with judicious early selections from Path I, can proceed to the Schwarzschild solution. The choice of material in each path is logical and focused. A notable example in Path I is that Lorentz transformations in Minkowki space are introduced
Directory of Open Access Journals (Sweden)
Bowie Paul
2012-06-01
Full Text Available Abstract Background Making health care safer is a key policy priority worldwide. In specialty training, medical educators may unintentionally impact on patient safety e.g. through failures of supervision; providing limited feedback on performance; and letting poorly developed behaviours continue unchecked. Doctors-in-training are also known to be susceptible to medical error. Ensuring that all essential educational issues are addressed during training is problematic given the scale of the tasks to be undertaken. Human error and the reliability of local systems may increase the risk of safety-critical topics being inadequately covered. However adherence to a checklist reminder may improve the reliability of task delivery and maximise harm reduction. We aimed to prioritise the most safety-critical issues to be addressed in the first 12-weeks of specialty training in the general practice environment and validate a related checklist reminder. Methods We used mixed methods with different groups of GP educators (n = 127 and specialty trainees (n = 9 in two Scottish regions to prioritise, develop and validate checklist content. Generation and refinement of checklist themes and items were undertaken on an iterative basis using a range of methods including small group work in dedicated workshops; a modified-Delphi process; and telephone interviews. The relevance of potential checklist items was rated using a 4-point scale content validity index to inform final inclusion. Results 14 themes (e.g. prescribing safely; dealing with medical emergency; implications of poor record keeping; and effective & safe communication and 47 related items (e.g. how to safety-net face-to-face or over the telephone; knowledge of practice systems for results handling; recognition of harm in children were judged to be essential safety-critical educational issues to be covered. The mean content validity index ratio was 0.98. Conclusion A checklist was developed and
Development and Validation of a Scale Measuring Approaches to Work-Related Informal Learning
Froehlich, Dominik E.; Beausaert, Simon; Segers, Mien
2017-01-01
Social approaches to work-related informal learning, such as proactive feedback-seeking, help-seeking and information-seeking, are important determinants of development in the workplace. Unfortunately, previous research has failed to clearly conceptualize these forms of learning and does not provide a validated and generally applicable measurement…
General scaling relations for locomotion in granular media
Slonaker, James; Motley, D. Carrington; Zhang, Qiong; Townsend, Stephen; Senatore, Carmine; Iagnemma, Karl; Kamrin, Ken
2017-05-01
Inspired by dynamic similarity in fluid systems, we have derived a general dimensionless form for locomotion in granular materials, which is validated in experiments and discrete element method (DEM) simulations. The form instructs how to scale size, mass, and driving parameters in order to relate dynamic behaviors of different locomotors in the same granular media. The scaling can be derived by assuming intrusion forces arise from resistive force theory or equivalently by assuming the granular material behaves as a continuum obeying a frictional yield criterion. The scalings are experimentally confirmed using pairs of wheels of various shapes and sizes under many driving conditions in a common sand bed. We discuss why the two models provide such a robust set of scaling laws even though they neglect a number of the complexities of granular rheology. Motivated by potential extraplanetary applications, the dimensionless form also implies a way to predict wheel performance in one ambient gravity based on tests in a different ambient gravity. We confirm this using DEM simulations, which show that scaling relations are satisfied over an array of driving modes even when gravity differs between scaled tests.
Criterion-Related Validity: Assessing the Value of Subscores
Davison, Mark L.; Davenport, Ernest C., Jr.; Chang, Yu-Feng; Vue, Kory; Su, Shiyang
2015-01-01
Criterion-related profile analysis (CPA) can be used to assess whether subscores of a test or test battery account for more criterion variance than does a single total score. Application of CPA to subscore evaluation is described, compared to alternative procedures, and illustrated using SAT data. Considerations other than validity and reliability…
Derivation of Einstein-Cartan theory from general relativity
Petti, Richard J
2013-01-01
General relativity cannot describe exchange of intrinsic and orbital angular momentum. In 1922 E. Cartan proposed extending general relativity by including affine torsion, which resolves this problem. In 1986 the author published a derivation of Einstein Cartan theory from general relativity with classical spin, with no additional assumptions. This paper summarizes the derivation and adds simpler explanations of the derivation and correction of a factor of 2.
The Two-Dimensional Analogue of General Relativity
Lemos, José P. S.; Sá, Paulo M.
1993-01-01
General Relativity in three or more dimensions can be obtained by taking the limit $\\omega\\rightarrow\\infty$ in the Brans-Dicke theory. In two dimensions General Relativity is an unacceptable theory. We show that the two-dimensional closest analogue of General Relativity is a theory that also arises in the limit $\\omega\\rightarrow\\infty$ of the two-dimensional Brans-Dicke theory.
Validation of general job satisfaction in the Korean Labor and Income Panel Study.
Park, Shin Goo; Hwang, Sang Hee
2017-01-01
The purpose of this study is to assess the validity and reliability of general job satisfaction (JS) in the Korean Labor and Income Panel Study (KLIPS). We used the data from the 17th wave (2014) of the nationwide KLIPS, which selected a representative panel sample of Korean households and individuals aged 15 or older residing in urban areas. We included in this study 7679 employed subjects (4529 males and 3150 females). The general JS instrument consisted of five items rated on a scale from 1 (strongly disagree) to 5 (strongly agree). The general JS reliability was assessed using the corrected item-total correlation and Cronbach's alpha coefficient. The validity of general JS was assessed using confirmatory factor analysis (CFA) and Pearson's correlation. The corrected item-total correlations ranged from 0.736 to 0.837. Therefore, no items were removed. Cronbach's alpha for general JS was 0.925, indicating excellent internal consistency. The CFA of the general JS model showed a good fit. Pearson's correlation coefficients for convergent validity showed moderate or strong correlations. The results obtained in our study confirm the validity and reliability of general JS.
Sturup, Joakim; Kristiansson, Marianne; Lindqvist, Per
2011-06-30
The objectives of the study are to report the 20-week base rate of violent behaviour in the community among a general psychiatric patient population from Stockholm and to establish the validity of a violence risk assessment software program, Classification of Violence Risk (COVR), in a European setting. Three hundred and thirty one patients at two psychiatric hospitals in Stockholm were interviewed upon discharge. Telephone interviews with the patients and collaterals were conducted 10 and 20 weeks later. The violent behaviour was also measured through a national criminal register. The allocation of patients into different risk groups according to COVR software was compared with the occurrence of actual acts of violence during the follow-up. The base rate of violent behaviour was 5.7% and a ROC-analysis showed that the AUC for COVR was 0.77. Since there were few patients in the high risk groups, the 95% confidence interval for the proportion of violent patients was wide. The base rate of violent behaviour is relatively low in Sweden and prediction is therefore difficult. The predictive validity of COVR software is comparable to other risk assessment tools. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Probing General Relativity and New Physics with Lunar Laser Ranging
Energy Technology Data Exchange (ETDEWEB)
Dell' Agnello, S. [Laboratori Nazionali di Frascati (LNF) dell' INFN, Frascati, Rome (Italy); Maiello, M., E-mail: mauro.maiello@lnf.infn.it [Laboratori Nazionali di Frascati (LNF) dell' INFN, Frascati, Rome (Italy); Currie, D.G. [University of Maryland (UMD), College Park, MD (United States); Boni, A.; Berardi, S.; Cantone, C.; Delle Monache, G.O.; Intaglietta, N.; Lops, C.; Garattini, M.; Martini, M.; Patrizi, G.; Porcelli, L.; Tibuzzi, M. [Laboratori Nazionali di Frascati (LNF) dell' INFN, Frascati, Rome (Italy); Vittori, R. [Aeronautica Militare Italiana (AMI), Rome (Italy); Agenzia Spaziale Italiana (ASI), Rome (Italy); Bianco, G. [ASI-Centro di Geodesia Spaziale, Matera (Italy); Coradini, A. [INAF-Istituto di Fisica dello Spazio Interplanetario (IFSI), Via Fosso del Cavaliere 100, 00133 Rome (Italy); Dionisio, C. [Rheinmetall Italia S.p.A., Via Affile 102, 00131 Rome (Italy); March, R. [INFN-LNF and CNR-Istituto per le Applicazioni del Calcolo (IAC), Viale del Policlinico 137, 00161 Rome (Italy); Bellettini, G. [INFN-LNF and Department of Mathematics, University of Rome ' Tor Vergata' , Via della Ricerca Scientifica, 00133 Rome (Italy); and others
2012-11-11
Over the past 40 years, Lunar Laser Ranging (LLR, developed by the Univ. of Maryland (PI) and INFN-LNF (Co-PI)) to the Apollo Cube Corner Retroreflector (CCR) arrays have supplied almost all the significant tests of General Relativity (Currie et al., 2009 [12]). LLR can evaluate the PPN (Post Newtonian Parameters), addressing this way both the possible changes in the gravitational constant and the self-energy properties of the gravitational field. In addition, the LLR has provided significant information on the composition and origin of the Moon. This is the only Apollo experiment that is still in operation. Initially the Apollo LLR arrays contributed a negligible fraction of the ranging error budget. Over the decades, the ranging capabilities of the ground stations have improved by more than two orders of magnitude. Now, because of the lunar librations, the existing Apollo retroreflector arrays contribute a significant fraction of the limiting errors in the range measurements. We built a new experimental apparatus (the 'Satellite/Lunar Laser Ranging Characterization Facility', SCF) and created a new test procedure (the SCF-Test) to characterize and model the detailed thermal behavior and the optical performance of cube corner laser retroreflectors in space for industrial and scientific applications (Dell'Agnello et al., 2011 [13]). Our key experimental innovation is the concurrent measurement and modeling of the optical Far Field Diffraction Pattern (FFDP) and the temperature distribution of the SLR retroreflector payload under thermal conditions produced with a close-match solar simulator. The apparatus includes infrared cameras for non-invasive thermometry, thermal control and real-time movement of the payload to experimentally simulate satellite orientation on orbit with respect to both solar illumination and laser interrogation beams. These unique capabilities provide experimental validation of the space segment for SLR and Lunar Laser Ranging
Probing General Relativity and New Physics with Lunar Laser Ranging
Dell'Agnello, S.; Maiello, M.; Currie, D. G.; Boni, A.; Berardi, S.; Cantone, C.; Delle Monache, G. O.; Intaglietta, N.; Lops, C.; Garattini, M.; Martini, M.; Patrizi, G.; Porcelli, L.; Tibuzzi, M.; Vittori, R.; Bianco, G.; Coradini, A.; Dionisio, C.; March, R.; Bellettini, G.; Tauraso, R.; Chandler, J.
2012-11-01
Over the past 40 years, Lunar Laser Ranging (LLR, developed by the Univ. of Maryland (PI) and INFN-LNF (Co-PI)) to the Apollo Cube Corner Retroreflector (CCR) arrays have supplied almost all the significant tests of General Relativity (Currie et al., 2009 [12]). LLR can evaluate the PPN (Post Newtonian Parameters), addressing this way both the possible changes in the gravitational constant and the self-energy properties of the gravitational field. In addition, the LLR has provided significant information on the composition and origin of the Moon. This is the only Apollo experiment that is still in operation. Initially the Apollo LLR arrays contributed a negligible fraction of the ranging error budget. Over the decades, the ranging capabilities of the ground stations have improved by more than two orders of magnitude. Now, because of the lunar librations, the existing Apollo retroreflector arrays contribute a significant fraction of the limiting errors in the range measurements. We built a new experimental apparatus (the ‘Satellite/Lunar Laser Ranging Characterization Facility', SCF) and created a new test procedure (the SCF-Test) to characterize and model the detailed thermal behavior and the optical performance of cube corner laser retroreflectors in space for industrial and scientific applications (Dell'Agnello et al., 2011 [13]). Our key experimental innovation is the concurrent measurement and modeling of the optical Far Field Diffraction Pattern (FFDP) and the temperature distribution of the SLR retroreflector payload under thermal conditions produced with a close-match solar simulator. The apparatus includes infrared cameras for non-invasive thermometry, thermal control and real-time movement of the payload to experimentally simulate satellite orientation on orbit with respect to both solar illumination and laser interrogation beams. These unique capabilities provide experimental validation of the space segment for SLR and Lunar Laser Ranging (LLR). The
Differential forms and the geometry of general relativity
Dray, Tevian
2015-01-01
Differential Forms and the Geometry of General Relativity provides readers with a coherent path to understanding relativity. Requiring little more than calculus and some linear algebra, it helps readers learn just enough differential geometry to grasp the basics of general relativity.The book contains two intertwined but distinct halves. Designed for advanced undergraduate or beginning graduate students in mathematics or physics, most of the text requires little more than familiarity with calculus and linear algebra. The first half presents an introduction to general relativity that describes
Bjerrum, L; Grinsted, P; Petersen, P H; Søgaard, P
2000-12-01
To investigate whether the validity of susceptibility testing in general practice would improve when preceded by an intervention. Instruction in standardised susceptibility testing procedures given by laboratory instructors. Urine specimens containing monocultures of typical uropathogenic bacteria were sent to 23 general practices before and after the intervention. Practices performed susceptibility testing by the Sensicult and the Iso-Res agar methods and the validity of the results before and after the intervention was compared. Results from susceptibility testing at the bacteriological laboratory, Odense University Hospital, were used as gold standard. The median frequency of correct results increased from 82% to 98% for susceptibility testing based on Sensicult (p = 0.001) and from 90% to 96% based on Iso-Res agar (p = 0.05). The validity of susceptibility testing in general practice improves when preceded by instruction in standardised procedures.
Transformational and transactional leadership: a meta-analytic test of their relative validity.
Judge, Timothy A; Piccolo, Ronald F
2004-10-01
This study provided a comprehensive examination of the full range of transformational, transactional, and laissez-faire leadership. Results (based on 626 correlations from 87 sources) revealed an overall validity of .44 for transformational leadership, and this validity generalized over longitudinal and multisource designs. Contingent reward (.39) and laissez-faire (-.37) leadership had the next highest overall relations; management by exception (active and passive) was inconsistently related to the criteria. Surprisingly, there were several criteria for which contingent reward leadership had stronger relations than did transformational leadership. Furthermore, transformational leadership was strongly correlated with contingent reward (.80) and laissez-faire (-.65) leadership. Transformational and contingent reward leadership generally predicted criteria controlling for the other leadership dimensions, although transformational leadership failed to predict leader job performance. (c) 2004 APA, all rights reserved
Subra, Julie; Chicoulaa, Bruno; Stillmunkès, André; Mesthé, Pierre; Oustric, Stéphane; Rougé Bugat, Marie-Eve
2017-12-01
The script concordance test (SCT) is a validated method of examining students' clinical reasoning. Medical students' professional skills are assessed during their postgraduate years as they study for a specialist qualification in general practice. However, no specific provision is made for assessing their clinical reasoning during their postgraduate study. The aim was to demonstrate the reliability and validity of the SCT in general practice and to determine if this tool could be used to assess medical students' progress in acquiring clinical reasoning. A 135-question SCT was administered to postgraduate medical students at the beginning of their first year of specialized training in general practice, and then every six months throughout their three-year training, as well as to a reference panel of 20 expert general practitioners. For score calculation, we used the combined scoring method as the calculator made available by the University of Montreal's School of Medicine in Canada. For the validity, student' scores were compared with experts, p <.05 was considered statistically significant. Ninety students completed all six assessments. The experts' mean score (76.7/100) was significantly higher than the students' score across all assessments (p <.001), with a Cronbach's alpha value of over 0.65 for all assessments. The SCT was found to be reliable and capable of discriminating between students and experts, demonstrating that this test is a valid tool for assessing clinical reasoning skills in general practice.
Proportionality: a valid alternative to correlation for relative data.
Directory of Open Access Journals (Sweden)
David Lovell
2015-03-01
Full Text Available In the life sciences, many measurement methods yield only the relative abundances of different components in a sample. With such relative-or compositional-data, differential expression needs careful interpretation, and correlation-a statistical workhorse for analyzing pairwise relationships-is an inappropriate measure of association. Using yeast gene expression data we show how correlation can be misleading and present proportionality as a valid alternative for relative data. We show how the strength of proportionality between two variables can be meaningfully and interpretably described by a new statistic ϕ which can be used instead of correlation as the basis of familiar analyses and visualisation methods, including co-expression networks and clustered heatmaps. While the main aim of this study is to present proportionality as a means to analyse relative data, it also raises intriguing questions about the molecular mechanisms underlying the proportional regulation of a range of yeast genes.
6th International Conference on the History of General Relativity
Eisenstaedt, Jean; The Universe of General Relativity; GR 6
2005-01-01
This volume from the Einstein Studies Series is based largely on papers presented at the Sixth International Conference on the History of General Relativity, held in Amsterdam on June 26-29, 2002. These contributions from notable experts offer both new and historical insights on gravitation, general relativity, cosmology, unified field theory, and the history of science. Topics discussed include the prehistory of special relativity, early attempts at a relativistic theory of gravitation, the beginnings of general relativity, the problem of motion in the context of relativity, conservation laws, the axiomatization of relativity, classical and contemporary cosmology, gravitation and electromagnetism, quantum gravity, and relativity as seen through the eyes of the public and renowned relativists. Contributors: K. Brading; G. Gale; H.F.M. Goenner; J. Goldberg; S. Katzir; D. Kennefick; H. Kragh; C. Lehner; U. Majer; J. Mattingly; E.T. Newman; J.D. Norton; J. Renn; R. Rynasiewicz; J.M. Sánchez-Ron; T. Sauer; C. Sm...
General Theory of Relativity-The Power of Speculative Thought
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 4. General Theory of Relativity – The Power of Speculative Thought. Asit Banerjee. General Article Volume 11 Issue 4 April 2006 pp 45-55. Fulltext. Click here to view fulltext PDF. Permanent link:
Understanding General Relativity after 100 years: A matter of perspective
Dadhich, Naresh
2016-01-01
This is the centenary year of general relativity, it is therefore natural to reflect on what perspective we have evolved in 100 years. I wish to share here a novel perspective, and the insights and directions that ensue from it.
General and special education teachers' relations within teamwork ...
African Journals Online (AJOL)
General and special education teachers' relations within teamwork in inclusive education: socio-demographic characteristics. M Radiæ-Šestic, V Radovanovic, B Milanovic-Dobrota, S Slavkovic, A Langoviæ-Milicvic ...
Relations between task delegation and job satisfaction in general practice
DEFF Research Database (Denmark)
Riisgaard, Helle; Nexøe, Jørgen; Videbæk Le, Jette
2016-01-01
BACKGROUND: It has for years been discussed whether practice staff should be involved in patient care in general practice to a higher extent. The research concerning task delegation within general practice is generally increasing, but the literature focusing on its influence on general practition......BACKGROUND: It has for years been discussed whether practice staff should be involved in patient care in general practice to a higher extent. The research concerning task delegation within general practice is generally increasing, but the literature focusing on its influence on general...... task delegation and general practitioners' and their staff's job satisfaction and, additionally, 2) to review the evidence of possible explanations for this relation. METHODS: A systematic literature review. We searched the four databases PubMed, Cinahl, Embase, and Scopus systematically. The immediate....... They explored views and attitudes of the staff, encompassing nurses as well as practice managers. Only one of the included studies also explored general practitioners' views and attitudes, hence making it impossible to establish any syntheses on this relation. According to the studies, the staff's overall...
Ginting, H.; Näring, G.W.B.; Veld, W.M. van der; Srisayekti, W.; Becker, E.S.
2013-01-01
This study assesses the validity and determines the cut-off point for the Beck Depression Inventory-II (the BDI-II) among Indonesians. The Indonesian version of the BDI-II (the Indo BDI-II) was administered to 720 healthy individuals from the general population, 215 Coronary Heart Disease (CHD)
Validation of a Test Measuring Young Learners' General L2 English Vocabulary Knowledge
Sylvén, Liss Kerstin; Sundqvist, Pia
2016-01-01
This study aims to present the validation of a test designed to assess young learners' general L2 English vocabulary knowledge, the Young Learner Vocabulary Assessment Test (YLVAT). YLVAT consists of 37 items selected from the K1-2 frequency levels of the Productive and Vocabulary Levels Tests. In the study, Swedish learners (N = 52, age 12) took…
Teacher Assistance Team Social Validity: A Perspective from General Education Teachers
Papalia-Berardi, Anne; Hall, Tracey E.
2007-01-01
General education teachers are the most frequent consumers of Teacher Assistance Team (TAT) services; therefore, their satisfaction with the purpose, process and outcome associated with this model of prereferral intervention may influence its acceptability, use, implementation, and effectiveness (social validity). Seven empirical studies assessing…
Large sample validations of three general predictors of pilot training success.
Burke, E; Hobson, C; Linsky, C
1997-01-01
This article addresses one of the perennial problems of pilot selection research: obtaining an adequate sample size for reliable statistical analysis of predictive validity. Results from three studies involving the same computerized tests of instrument comprehension and psychomotor ability were combined in a meta-analysis to determine whether the validities of these tests generalized across three contexts. These were Royal Air Force and Turkish Air Force fixed-wing pilot training and British Army Air Corps rotary-wing pilot training. In this article, we discuss the adequacy of samples for estimating the validity of the tests, and the persistence of predictive validity to later stages of training as shown by British Army Air Corps data. Reference is also made to data from a fourth independent study of Qantas pilot training.
McAbee, Samuel T; Oswald, Frederick L
2013-06-01
Interest in the role of personality traits in predicting academic performance outcomes has steadily increased over the last several decades, enough to produce a number of meta-analyses that summarize this research (e.g., Poropat, 2009; Richardson, Abraham, & Bond, 2012). These previous meta-analyses combine a variety of alternative personality measures under the assumption that they all reflect the same personality traits and thus predict outcomes similarly. The current meta-analysis tests this assumption by comparing different personality measures when predicting postsecondary grade point average (GPA). The operational validities (r+) of 5 frequently used measures of the Big Five personality traits were compared: the NEO Personality Inventory--Revised (NEO-PI-R; Costa & McCrae, 1992), the NEO Five-Factor Inventory (NEO-FFI; Costa & McCrae, 1992), the Big Five Inventory (BFI; e.g., Benet-Martínez & John, 1998), Goldberg's (1992) unipolar Big Five Factor Markers (Markers), and the Big Five International Personality Item Pool (IPIP; Goldberg, 1999). A systematic review of the psychological literature from 1992 to 2012 was conducted, identifying 51 studies containing 274 correlations. Conscientiousness demonstrated the strongest criterion-related validity for predicting GPA (r+ = .23), consistent with previous meta-analyses; in addition, this overall validity was found to be robust across measures (r(BFI)(+) = .24, r(IPIP)(+) = .21, r(Markers)(+) = .15, r(NEO-FFI)(+) = .24, r(NEO-PI-R)(+) = .26). Although the criterion-related validities for Extraversion, Agreeableness, Neuroticism, and Openness to Experience (Intellect) differed by measure, they were generally low (r+s < .10). Practical implications of the findings and directions for future research are discussed. PsycINFO Database Record (c) 2013 APA, all rights reserved.
Charisma in everyday life: Conceptualization and validation of the General Charisma Inventory.
Tskhay, Konstantin O; Zhu, Rebecca; Zou, Christopher; Rule, Nicholas O
2018-01-01
Although both scholars and lay people are fascinated with charismatic individuals, relatively few theorists have attempted to define charisma. Much of the empirical research examining charisma has focused on leadership. Even within that literature, however, theorists have focused on charisma's outcomes, leaving unarticulated what charisma actually is. Here, we tested an operational conceptualization of charisma in the context of everyday life. Specifically, we proposed that charisma is composed of the interpersonally focused dimensions of influence (the ability to guide others) and affability (the ability to make other people feel comfortable and at ease). We validated this conceptualization in a series of studies. In Studies 1-3, we used exploratory and confirmatory factor analyses to construct a short 6-item measure of charisma, the General Charisma Inventory. Next, in Study 4, we used round-robin evaluations and informant reports to establish the interpersonal nature of charisma. Finally, we examined the incremental validity of the scale in the context of dyadic interactions and tested the impact of charisma on perceptions of persuasiveness from voices. We found that (a) lay people possess a consensual conception of charisma; (b) charisma consists of a composition of quantifiable dimensions; (c) charisma is distinct from other constructs of interest to psychologists and leadership theorists; (d) charisma is observable; and (e) assessments of charisma predict real world outcomes. Thus, the current work not only comprehensively conceptualizes and measures charisma as an empirical construct, but also demonstrates its potential importance for the routine interactions that people experience every day. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Implications of a positive cosmological constant for general relativity
Ashtekar, Abhay
2017-10-01
Most of the literature on general relativity over the last century assumes that the cosmological constant Λ is zero. However, by now independent observations have led to a consensus that the dynamics of the universe is best described by Einstein’s equations with a small but positive Λ . Interestingly, this requires a drastic revision of conceptual frameworks commonly used in general relativity, no matter how small Λ is. We first explain why, and then summarize the current status of generalizations of these frameworks to include a positive Λ , focusing on gravitational waves.
Implications of a positive cosmological constant for general relativity.
Ashtekar, Abhay
2017-10-01
Most of the literature on general relativity over the last century assumes that the cosmological constant [Formula: see text] is zero. However, by now independent observations have led to a consensus that the dynamics of the universe is best described by Einstein's equations with a small but positive [Formula: see text]. Interestingly, this requires a drastic revision of conceptual frameworks commonly used in general relativity, no matter how small [Formula: see text] is. We first explain why, and then summarize the current status of generalizations of these frameworks to include a positive [Formula: see text], focusing on gravitational waves.
The general class of the vacuum spherically symmetric equations of the general relativity theory
Energy Technology Data Exchange (ETDEWEB)
Karbanovski, V. V., E-mail: Karbanovski_V_V@mail.ru; Sorokin, O. M.; Nesterova, M. I.; Bolotnyaya, V. A.; Markov, V. N., E-mail: Markov_Victor@mail.ru; Kairov, T. V.; Lyash, A. A.; Tarasyuk, O. R. [Murmansk State Pedagogical University (Russian Federation)
2012-08-15
The system of the spherical-symmetric vacuum equations of the General Relativity Theory is considered. The general solution to a problem representing two classes of line elements with arbitrary functions g{sub 00} and g{sub 22} is obtained. The properties of the found solutions are analyzed.
The general theory of relativity a mathematical exposition
Das, Anadijiban
2012-01-01
The General Theory of Relativity: A Mathematical Exposition will serve readers as a modern mathematical introduction to the general theory of relativity. Throughout the book, examples, worked-out problems, and exercises (with hints and solutions) are furnished. Topics in this book include, but are not limited to: • tensor analysis • the special theory of relativity • the general theory of relativity and Einstein’s field equations • spherically symmetric solutions and experimental confirmations • static and stationary space-time domains • black holes • cosmological models • algebraic classifications and the Newman-Penrose equations • the coupled Einstein-Maxwell-Klein-Gordon equations • appendices covering mathematical supplements and special topics Mathematical rigor, yet very clear presentation of the topics make this book a unique text for both university students and research scholars. Anadijiban Das has taught courses on Relativity Theory at The University College of Dublin, Irelan...
Overgeneralization of validity generalization in personality inventories: applied issues in testing.
Tiffany, D W; Tiffany, P G
1999-04-01
Generalization of validity asserts that a predictor or criterion generalizes across studies and will continue to show similar parameters when the situation changes. Kurt Lewin explored situation-behavior relationships, and Mischel examined the situation-behavior association showing predictive accuracy between behaviors and contexts. Investigators have critically reproached the assumed generalization of assessment instruments that ignore contextual variance. The validity hypothesis confirmed that using nonsituation-specific scales does not focus on the contextual effects relevant to the criterion measured and consequently has no practical application for focused evaluation in clinical and employment settings. This study describes a model and technique for the measurement of contextual variance in personality dimensions thereby introducing situation-specificity in evaluation for more focused research, treatment, and a more specific job fit in employment settings.
Relative Entropy and Variational Properties of Generalized Gibbsian Measures
Külske, Christof; Ny, Arnaud Le; Redig, Frank
2004-01-01
We study the relative entropy density for generalized Gibbs measures. We first show its existence and obtain a familiar expression in terms of entropy and relative energy for a class of “almost Gibbsian measures” (almost sure continuity of conditional probabilities). For quasilocal measures, we
A remark on generalized commutation relation and subnormality
Directory of Open Access Journals (Sweden)
Jerzy Bartłomiej Stochel
2006-01-01
Full Text Available Tillmann [Tillmann H. G., Zur Eindeutigkeit der Losungen der quanten mechanischen vertauschungrelationen, Acta Sci. Math. (Szeged 24 (1963, 258-270] proved that every operator \\(A\\ which fulfils the canonical commutation relation \\(A^{*}A - AA^{*} = Id\\ is an orthogonal sum of canonical creation operators. We extend this result for operators which fulfil generalized commutation relation \\[A^{*}A - AA^{*}= E^2,\\text{ where }EA = AE.\\] In addition, some inequalities which are helpful in describing analytic vectors of operators \\(A^{*}A\\, where \\(A\\ fulfils the generalized commutation relation, are established.
Criterion Related Validity of Karate Specific Aerobic Test (KSAT).
Chaabene, Helmi; Hachana, Younes; Franchini, Emerson; Tabben, Montassar; Mkaouer, Bessem; Negra, Yassine; Hammami, Mehrez; Chamari, Karim
2015-09-01
Karate is one the most popular combat sports in the world. Physical fitness assessment on a regular manner is important for monitoring the effectiveness of the training program and the readiness of karatekas to compete. The aim of this research was to examine the criterion related to validity of the karate specific aerobic test (KSAT) as an indicator of aerobic level of karate practitioners. Cardiorespiratory responses, aerobic performance level through both treadmill laboratory test and YoYo intermittent recovery test level 1 (YoYoIRTL1) as well as time to exhaustion in the KSAT test (TE'KSAT) were determined in a total of fifteen healthy international karatekas (i.e. karate practitioners) (means ± SD: age: 22.2 ± 4.3 years; height: 176.4 ± 7.5 cm; body mass: 70.3 ± 9.7 kg and body fat: 13.2 ± 6%). Peak heart rate obtained from KSAT represented ~99% of maximal heart rate registered during the treadmill test showing that KSAT imposes high physiological demands. There was no significant correlation between KSAT's TE and relative (mL/min kg) treadmill maximal oxygen uptake (r = 0.14; P = 0.69; [small]). On the other hand, there was a significant relationship between KSAT's TE and the velocity associated with VO2max (vVO2max) (r = 0.67; P = 0.03; [large]) as well as the velocity at VO2 corresponding to the second ventilatory threshold (vVO2 VAT) (r = 0.64; P = 0.04; [large]). Moreover, significant relationship was found between TE's KSAT and both the total distance covered and parameters of intermittent endurance measured through YoYoIRTL1. The KSAT has not proved to have indirect criterion related validity as no significant correlations have been found between TE's KSAT and treadmill VO2max. Nevertheless, as correlated to other aerobic fitness variables, KSAT can be considered as an indicator of karate specific endurance. The establishment of the criterion related validity of the KSAT requires further investigation.
Criterion Related Validity of Karate Specific Aerobic Test (KSAT)
Chaabene, Helmi; Hachana, Younes; Franchini, Emerson; Tabben, Montassar; Mkaouer, Bessem; Negra, Yassine; Hammami, Mehrez; Chamari, Karim
2015-01-01
Background: Karate is one the most popular combat sports in the world. Physical fitness assessment on a regular manner is important for monitoring the effectiveness of the training program and the readiness of karatekas to compete. Objectives: The aim of this research was to examine the criterion related to validity of the karate specific aerobic test (KSAT) as an indicator of aerobic level of karate practitioners. Patients and Methods: Cardiorespiratory responses, aerobic performance level through both treadmill laboratory test and YoYo intermittent recovery test level 1 (YoYoIRTL1) as well as time to exhaustion in the KSAT test (TE’KSAT) were determined in a total of fifteen healthy international karatekas (i.e. karate practitioners) (means ± SD: age: 22.2 ± 4.3 years; height: 176.4 ± 7.5 cm; body mass: 70.3 ± 9.7 kg and body fat: 13.2 ± 6%). Results: Peak heart rate obtained from KSAT represented ~99% of maximal heart rate registered during the treadmill test showing that KSAT imposes high physiological demands. There was no significant correlation between KSAT’s TE and relative (mL/min kg) treadmill maximal oxygen uptake (r = 0.14; P = 0.69; [small]). On the other hand, there was a significant relationship between KSAT’s TE and the velocity associated with VO2max (vVO2max) (r = 0.67; P = 0.03; [large]) as well as the velocity at VO2 corresponding to the second ventilatory threshold (vVO2 VAT) (r = 0.64; P = 0.04; [large]). Moreover, significant relationship was found between TE’s KSAT and both the total distance covered and parameters of intermittent endurance measured through YoYoIRTL1. Conclusions: The KSAT has not proved to have indirect criterion related validity as no significant correlations have been found between TE’s KSAT and treadmill VO2max. Nevertheless, as correlated to other aerobic fitness variables, KSAT can be considered as an indicator of karate specific endurance. The establishment of the criterion related validity of the KSAT
Generalization of Pain-Related Fear Based on Conceptual Knowledge.
Meulders, Ann; Vandael, Kristof; Vlaeyen, Johan W S
2017-05-01
Increasing evidence suggests that pain-related fear is key to the transition from acute to chronic pain. Previous research has shown that perceptual similarity with a pain-associated movement fosters the generalization of fear to novel movements. Perceptual generalization of pain-related fear is adaptive as it enables individuals to extrapolate the threat value of one movement to another without the necessity to learn anew. However, excessive spreading of fear to safe movements may become maladaptive and may lead to sustained anxiety, dysfunctional avoidance behaviors, and severe disability. A hallmark of human cognition is the ability to extract conceptual knowledge from a learning episode as well. Although this conceptual pathway may be important to understand fear generalization in chronic pain, research on this topic is lacking. We investigated acquisition and generalization of concept-based pain-related fear. During acquisition, unique exemplars of one action category (CS+; e.g., opening boxes) were followed by pain, whereas exemplars of another action category (CS-; e.g., closing boxes) were not. Subsequently, spreading of pain-related fear to novel exemplars of both action categories was tested. Participants learned to expect the pain to occur and reported more pain-related fear to the exemplars of the CS+ category compared with those of the CS- category. During generalization, fear and expectancy generalized to novel exemplars of the CS+ category, but not to the CS- category. This pattern was not corroborated in the eyeblink startle measures. This is the first study that demonstrates that pain-related fear can be acquired and generalized based on conceptual knowledge. Copyright © 2016. Published by Elsevier Ltd.
Development and initial validation of a content taxonomy for patient records in general dentistry.
Acharya, Amit; Hernandez, Pedro; Thyvalikakath, Thankam; Ye, Harold; Song, Mei; Schleyer, Titus
2013-12-01
Develop and validate an initial content taxonomy for patient records in general dentistry. Phase 1 - obtain 95 de-identified patient records from 11 general dentists in the United States. Phase 2 - extract individual data fields (information items), both explicit (labeled) and implicit (unlabeled), from records, and organize into categories mirroring original field context. Phase 3 - refine raw list of information items by eliminating duplicates/redundancies and focusing on general dentistry. Phase 4 - validate all items regarding inclusion and importance using a two-round Delphi study with a panel of 22 general dentists active in clinical practice, education, and research. Analysis of 76 patient records from 9 dentists, combined with previous work, yielded a raw list of 1509 information items. Refinement reduced this list to 1107 items, subsequently rated by the Delphi panel. The final model contained 870 items, with 761 (88%) rated as mandatory. In Round 1, 95% (825) of the final items were accepted, in Round 2 the remaining 5% (45). Only 45 items on the initial list were rejected and 192 (or 17%) remained equivocal. Grounded in the reality of clinical practice, our proposed content taxonomy represents a significant advance over existing guidelines and standards by providing a granular and comprehensive information representation for general dental patient records. It offers a significant foundational asset for implementing an interoperable health information technology infrastructure for general dentistry. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Corrigendum to ;Testing general relativity on accelerators; [Phys. Lett. B 750 (2015) 112-116
Kalaydzhyan, Tigran
2017-11-01
I worked on Ref. [1] initially, but disagreement with the author of Ref. [1] on the physical conclusions led to this work. As a result there are textual overlaps with Ref. [1]. The paper differs in many ways from Ref. [1] and, even though some of the mathematical expressions look similar on a superficial level, I obtained opposite conclusions to the ones proposed in Ref. [1]. In particular, Ref. [1] states that the considered experiments contradict general relativity, while I state that they confirm validity of the general relativity within the given experimental precision.
Energy Technology Data Exchange (ETDEWEB)
Boero, Riccardo [Los Alamos National Laboratory; Edwards, Brian Keith [Los Alamos National Laboratory
2017-08-07
Economists use computable general equilibrium (CGE) models to assess how economies react and self-organize after changes in policies, technology, and other exogenous shocks. CGE models are equation-based, empirically calibrated, and inspired by Neoclassical economic theory. The focus of this work was to validate the National Infrastructure Simulation and Analysis Center (NISAC) CGE model and apply it to the problem of assessing the economic impacts of severe events. We used the 2012 Hurricane Sandy event as our validation case. In particular, this work first introduces the model and then describes the validation approach and the empirical data available for studying the event of focus. Shocks to the model are then formalized and applied. Finally, model results and limitations are presented and discussed, pointing out both the model degree of accuracy and the assessed total damage caused by Hurricane Sandy.
The gyromagnetic factor in electrodynamics, quantum theory and general relativity
Pfister, H D
2003-01-01
Starting with some basic facts about the gyromagnetic factor g in Maxwell's theory, we review the special role played by a g factor g=2 in quantum mechanics and elementary particle physics, and we draw attention to the same value g=2 for the black holes and many other (electro-)vacuum solutions of general relativity. We strengthen and extend this special role of g=2 in general relativity by considering a class of slowly rotating, charged mass shells, showing that the black-hole value g=2 is extremely robust. Therefrom, we advance the hypothesis that the coincidence between these preferred g values signifies a deep common root of quantum theory and general relativity.
Testing General Relativity with Present and Future Astrophysical Observations
Berti, Emanuele; Cardoso, Vitor; Gualtieri, Leonardo; Pani, Paolo; Sperhake, Ulrich; Stein, Leo C; Wex, Norbert; Yagi, Kent; Baker, Tessa; Burgess, C P; Coelho, Flávio S; Doneva, Daniela; De Felice, Antonio; Ferreira, Pedro G; Freire, Paulo C C; Healy, James; Herdeiro, Carlos; Horbatsch, Michael; Kleihaus, Burkhard; Klein, Antoine; Kokkotas, Kostas; Kunz, Jutta; Laguna, Pablo; Lang, Ryan N; Li, Tjonnie G F; Littenberg, Tyson; Matas, Andrew; Mirshekari, Saeed; Okawa, Hirotada; Radu, Eugen; O'Shaughnessy, Richard; Sathyaprakash, Bangalore S; Broeck, Chris Van Den; Winther, Hans A; Witek, Helvi; Aghili, Mir Emad; Alsing, Justin; Bolen, Brett; Bombelli, Luca; Caudill, Sarah; Chen, Liang; Degollado, Juan Carlos; Fujita, Ryuichi; Gao, Caixia; Gerosa, Davide; Kamali, Saeed; Silva, Hector O; Rosa, João G; Sadeghian, Laleh; Sampaio, Marco; Sotani, Hajime; Zilhao, Miguel
2015-01-01
One century after its formulation, Einstein's general relativity has made remarkable predictions and turned out to be compatible with all experimental tests. Most (if not all) of these tests probe the theory in the weak-field regime, and there are theoretical and experimental reasons to believe that general relativity should be modified when gravitational fields are strong and spacetime curvature is large. The best astrophysical laboratories to probe strong-field gravity are black holes and neutron stars, whether isolated or in binary systems. We review the motivations to consider extensions of general relativity. We present a (necessarily incomplete) catalog of modified theories of gravity for which strong-field predictions have been computed and contrasted to Einstein's theory, and we summarize our current understanding of the structure and dynamics of compact objects in these theories. We discuss current bounds on modified gravity from binary pulsar and cosmological observations, and we highlight the poten...
Introduction to general relativity, black holes and cosmology
Choquet-Bruhat, Yvonne
2015-01-01
General Relativity is a beautiful geometric theory, simple in its mathematical formulation but leading to numerous consequences with striking physical interpretations: gravitational waves, black holes, cosmological models, and so on. This introductory textbook is written for mathematics students interested in physics and physics students interested in exact mathematical formulations (or for anyone with a scientific mind who is curious to know more of the world we live in), recent remarkable experimental and observational results which confirm the theory are clearly described and no specialised physics knowledge is required. The mathematical level of Part A is aimed at undergraduate students and could be the basis for a course on General Relativity. Part B is more advanced, but still does not require sophisticated mathematics. Based on Yvonne Choquet-Bruhat's more advanced text, General Relativity and the Einstein Equations, the aim of this book is to give with precision, but as simply as possible, the found...
Validation of AIDS-related mortality in Botswana
Directory of Open Access Journals (Sweden)
Taffa Negussie
2009-10-01
Full Text Available Abstract Background Mortality data are used to conduct disease surveillance, describe health status and inform planning processes for health service provision and resource allocation. In many countries, HIV- and AIDS-related deaths are believed to be under-reported in government statistics. Methods To estimate the extent of under-reporting of HIV- and AIDS-related deaths in Botswana, we conducted a retrospective study of a sample of deaths reported in the government vital registration database from eight hospitals, where more than 40% of deaths in the country in 2005 occurred. We used the consensus of three physicians conducting independent reviews of medical records as the gold standard comparison. We examined the sensitivity, specificity and other validity statistics. Results Of the 5276 deaths registered in the eight hospitals, 29% were HIV- and AIDS-related. The percentage of HIV- and AIDS-related deaths confirmed by physician consensus (positive predictive value was 95.4%; however, the percentage of non-HIV- and non-AIDS-related deaths confirmed (negative predictive value was only 69.1%. The sensitivity and specificity of the vital registration system was 55.7% and 97.3%, respectively. After correcting for misclassification, the percentage of HIV- and AIDS--related deaths was estimated to be in the range of 48.8% to 54.4%, depending on the definition. Conclusion Improvements in hospitals and within government offices are necessary to strengthen the vital registration system. These should include such strategies as training physicians and coders in accurate reporting and recording of death statistics, implementing continuous quality assurance methods, and working with the government to underscore the importance of using mortality statistics in future evidence-based planning.
Generalizing about Public Health Interventions: A Mixed-Methods Approach to External Validity.
Leviton, Laura C
2017-03-20
Public health researchers and practitioners are calling for greater focus on external validity, the ability to generalize findings of evidence-based interventions (EBIs) beyond the limited number of studies testing effectiveness. For public health, the goal is applicability: to translate, disseminate, and implement EBIs for an impact on population health. This article is a review of methods and how they might be combined to better assess external validity. The methods include (a) better description of EBIs and their contexts; (b) combining of statistical tools and logic to draw inferences about study samples; (c) sharper definition of the theory behind the intervention and core intervention components; and (d) more systematic consultation of practitioners. For population impact, studies should focus on context features that are likely to be both important (based on program theory) and frequently encountered by practitioners. Mixed-method programs of research will allow public health to expand causal generalizations.
New Superpotential in Conservation Laws in General Relativity
Adamek, J
2016-01-01
This work refers to the new formula for the superpotential Uikl in conservation laws in general relativity satisfying the integral and differential conservation laws within the Schwarzschild metric. The new superpotential is composed of two terms. The first term is based on Mollers concept and its a function of the metric gik and its first derivative only. The second term is the antisymmetric tensor density of weight plus one and it consists of higher derivatives of the metric gik. Although the new superpotential consists of higher derivatives of the metric gik it might bring a new evaluation of the conservative quantities in general relativity
Essays in general relativity a Festschrift for Abraham Taub
Tipler, Frank J
1981-01-01
Essays in General Relativity: A Festschrift for Abraham Taub is collection of essays to honor Professor Abraham H. Taub on the occasion of his retirement from the mathematics faculty of the University of California at Berkeley. Relativistic hydrodynamics has always been a subject dear to Taub's heart. In fact, many basic results on special relativistic fluid flows are due to him, and he has been a major contributor to the study of fluid flows near shocks. The book contains 16 chapters and begins with a discussion of a geometrical approach to general relativity. This is followed by separate cha
On the mathematical theory of classical fields and general relativity
Klainerman, S
1993-01-01
From the perspective of an analyst, like myself, the General Theory of Relativity provides an extrordinary rich and vastly virgin territory. It is the aim of my lecture to provide, ﬁrst, an account of those aspects of the theory which attract me most and second a perspective of what has been accomplished so far in that respect. In trying to state our main objectives it helps to view General Relativity in the broader context of Classical Field Theory. EinsteiniVacuum equations, or shortly E—V, is already sufﬁciently complicated. I will thus restrict my attention to them.
Directory of Open Access Journals (Sweden)
Garmaroudi Gholamreza
2003-11-01
Full Text Available Abstract Background The objective of this study was to translate and to test the reliability and validity of the 12-item General Health Questionnaire (GHQ-12 in Iran. Methods Using a standard 'forward-backward' translation procedure, the English language version of the questionnaire was translated into Persian (Iranian language. Then a sample of young people aged 18 to 25 years old completed the questionnaire. In addition, a short questionnaire containing demographic questions and a single measure of global quality of life was administered. To test reliability the internal consistency was assessed by Cronbach's alpha coefficient. Validity was performed using convergent validity. Finally, the factor structure of the questionnaire was extracted by performing principal component analysis using oblique factor solution. Results In all 748 young people entered into the study. The mean age of respondents was 21.1 (SD = 2.1 years. Employing the recommended method of scoring (ranging from 0 to 12, the mean GHQ score was 3.7 (SD = 3.5. Reliability analysis showed satisfactory result (Cronbach's alpha coefficient = 0.87. Convergent validity indicated a significant negative correlation between the GHQ-12 and global quality of life scores as expected (r = -0.56, P Conclusion The study findings showed that the Iranian version of the GHQ-12 has a good structural characteristic and is a reliable and valid instrument that can be used for measuring psychological well being in Iran.
Directory of Open Access Journals (Sweden)
Elizabeth Gomes dos Santos
Full Text Available Objective: To develop and validate an instrument for measuring the acquisition of technical skills in conducting operations of increasing difficulty for use in General Surgery Residency (GSR programs. Methods: we built a surgical skills assessment tool containing 11 operations in increasing levels of difficulty. For instrument validation we used the face validaity method. Through an electronic survey tool (Survey MonKey(r we sent a questionnaire to Full and Emeritus members of the Brazilian College of Surgeons - CBC - all bearers of the CBC Specialist Title. Results: Of the 307 questionnaires sent we received 100 responses. For the analysis of the data collected we used the Cronbach's alpha test. We observed that, in general, the overall alpha presented with values near or greater than 0.70, meaning good consistency to assess their points of interest. Conclusion: The evaluation instrument built was validated and can be used as a method of assessment of technical skill acquisition in the General Surgery Residency programs in Brazil.
General relativity at 75: how right was einstein?
Will, C M
1990-11-09
The status of experimental tests of general relativity is reviewed on the occasion of its 75th anniversary. Einstein's equivalence principle is well supported by experiments such as the Eötvös experiment, tests of special relativity, and the gravitational redshift experiment. Tests of general relativity have reached high precision, including the light deflection and the perihelion advance of Mercury, proposed by Einstein 75 years ago, and new tests such as the Shapiro time delay and the Nordtvedt effect in lunar motion. Gravitational wave damping has been detected to an accuracy of 1 percent on the basis of measurements of the binary pulsar. The status of the "fifth force" is discussed, along with the frontiers of experimental relativity, including proposals for testing relativistic gravity with advanced technology and spacecraft.
Doppler frequency in interplanetary radar and general relativity
Mcvittie, G. C.
1972-01-01
The change of frequency of an interplanetary radar signal sent from the earth to another planet or to a space probe is worked out according to general relativity. The Schwarzschild spacetime is employed and its null geodesics control the motion of the signals. Exact Doppler frequency formulas are derived for one-way and two-way radar in terms of an arbitrary Schwarzschild radial coordinate. A reduction to the special relativity case is used to interpret the formulas in terms of the relative radial velocity of emitter and target. The general relativity corrections are worked out approximately for each of three possible Schwarzschild radial coordinates, and a numerical example is given. The amount of the correction is different according as one or the other of the Schwarzschild coordinates is identified with the radius vector deduced from classical celestial mechanics. The identification problem is discussed.
Arithmetic for the unification of quantum mechanics and general relativity
Energy Technology Data Exchange (ETDEWEB)
Korotkikh, Victor, E-mail: v.korotkikh@cqu.edu.a [School of Computing Sciences, Faculty of Business and Informatics, Central Queensland University, Mackay, Queensland, 4740 (Australia)
2009-06-01
In the paper we bring attention to description of complex systems in terms of self-organization processes of prime integer relations. Revealed through the unity of two equivalent forms, arithmetical and geometrical, the description may have the potential for the unification of quantum mechanics and general relativity. Remarkably, based on integers and controlled by arithmetic only such processes can define nonlocal correlations between parts of a complex system and the geometry of their spacetimes.
BOOK REVIEW: Partial Differential Equations in General Relativity
Halburd, Rodney G.
2008-11-01
Although many books on general relativity contain an overview of the relevant background material from differential geometry, very little attention is usually paid to background material from the theory of differential equations. This is understandable in a first course on relativity but it often limits the kinds of problems that can be studied rigorously. Einstein's field equations lie at the heart of general relativity. They are a system of partial differential equations (PDEs) relating the curvature of spacetime to properties of matter. A central part of most problems in general relativity is to extract information about solutions of these equations. Most standard texts achieve this by studying exact solutions or numerical and analytical approximations. In the book under review, Alan Rendall emphasises the role of rigorous qualitative methods in general relativity. There has long been a need for such a book, giving a broad overview of the relevant background from the theory of partial differential equations, and not just from differential geometry. It should be noted that the book also covers the basic theory of ordinary differential equations. Although there are many good books on the rigorous theory of PDEs, methods related to the Einstein equations deserve special attention, not only because of the complexity and importance of these equations, but because these equations do not fit into any of the standard classes of equations (elliptic, parabolic, hyperbolic) that one typically encounters in a course on PDEs. Even specifying exactly what ones means by a Cauchy problem in general relativity requires considerable care. The main problem here is that the manifold on which the solution is defined is determined by the solution itself. This means that one does not simply define data on a submanifold. Rendall's book gives a good overview of applications and results from the qualitative theory of PDEs to general relativity. It would be impossible to give detailed
de Montbrun, Sandra; Louridas, Marisa; Szasz, Peter; Harris, Kenneth A; Grantcharov, Teodor P
2017-08-29
There is a recognized need to develop high-stakes technical skills assessments for decisions of certification and resident promotion. High-stakes examinations requires a rigorous approach in accruing validity evidence throughout the developmental process. One of the first steps in development is the creation of a blueprint which outlines the potential content of examination. The purpose of this validation study was to develop an examination blueprint for a Canadian General Surgery assessment of technical skill certifying examination. A Delphi methodology was used to gain consensus amongst Canadian General Surgery program directors as to the content (tasks or procedures) that could be included in a certifying Canadian General Surgery examination. Consensus was defined a priori as a Cronbach's α ≥ 0.70. All procedures or tasks reaching a positive consensus (defined as ≥80% of program directors rated items as ≥4 on the 5-point Likert scale) were then included in the final examination blueprint. Two Delphi rounds were needed to reach consensus. Of the 17 General Surgery Program directors across the country, 14 (82.4%) and 10 (58.8%) program directors responded to the first and second round, respectively. A total of 59 items and procedures reached positive consensus and were included in the final examination blueprint. The present study has outlined the development of an examination blueprint for a General Surgery certifying examination using a consensus-based methodology. This validation study will serve as the foundational work from which simulated model will be developed, pilot tested and evaluated. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
Bianchi type-V string cosmological models in general relativity
Indian Academy of Sciences (India)
Abstract. Bianchi type-V string cosmological models in general relativity are investigated. To get the exact solution of Einstein's field equations, we have taken some scale transformations used by Camci et al [Astrophys. Space Sci. 275, 391 (2001)]. It is shown that Einstein's field equations are solvable for any arbitrary ...
Bianchi type-V string cosmological models in general relativity
Indian Academy of Sciences (India)
Bianchi type-V string cosmological models in general relativity are investigated. To get the exact solution of Einstein's ﬁeld equations, we have taken some scale transformations used by Camci et al [Astrophys. Space Sci. 275, 391 (2001)]. It is shown that Einstein's ﬁeld equations are solvable for any arbitrary cosmic scale ...
Bianchi type IX string cosmological model in general relativity
Indian Academy of Sciences (India)
Abstract. We have investigated Bianchi type IX string cosmological models in general relativity. To get a determinate solution, we have assumed a condition p = λ i.e. rest energy density for a cloud of strings is equal to the string tension density. The various physical and geometrical aspects of the models are also discussed.
Relations between task delegation and job satisfaction in general practice
DEFF Research Database (Denmark)
Riisgaard, Helle; Nexøe, Jørgen; Videbæk Le, Jette
2016-01-01
task delegation and general practitioners' and their staff's job satisfaction and, additionally, 2) to review the evidence of possible explanations for this relation. METHODS: A systematic literature review. We searched the four databases PubMed, Cinahl, Embase, and Scopus systematically. The immediate...
Testing General Relativity Using Gravitational-Wave Observations
Indian Academy of Sciences (India)
Testing General Relativity Using Gravitational-Wave. Observations. Parameswaran Ajith ICTS-TIFR, Bangalore. On behalf of the LIGO Scientific Collaboration and. Virgo Collaboration. 27th Mid-Year Meeting of the Indian Academy of Sciences. 1 July 2016, IISc Bangalore. LIGO-G1601410-v2 indig ...
Related General-Vocabulary Knowledge Transfers to Learning Technical Terms
Balch, William R.
2015-01-01
In a classroom experiment during the first week of an introductory psychology course, randomly assigned students received a pretest and then a brief training on the definitions of general-vocabulary words either related (e.g., "facilitation") or unrelated (e.g., "rendition") to 16 technical terms (e.g., "social…
Galileons as the Scalar Analogue of General Relativity
Klein, Remko; Ozkan, Mehmet; Roest, Diederik
2016-01-01
We establish a correspondence between general relativity with diffeomorphism invariance and scalar field theories with Galilean invariance: notions such as the Levi-Civita connection and the Riemann tensor have a Galilean counterpart. This suggests Galilean theories as the unique nontrivial
Collineations of the curvature tensor in general relativity
Indian Academy of Sciences (India)
The general theory of relativity, which is a field theory of gravitation, is described by the Einstein field equations. These equations whose fundamental constituent is the space-time metric gij, are highly non-linear partial differential equations and, therefore it is very difficult to obtain exact solutions. They become still more diffi-.
Probing Students' Understanding of Some Conceptual Themes in General Relativity
Bandyopadhyay, Atanu; Kumar, Arvind
2010-01-01
This work is an attempt to see how physics undergraduates view the basic ideas of general relativity when they are exposed to the topic in a standard introductory course. Since the subject is conceptually and technically difficult, we adopted a "case studies" approach, focusing in depth on about six students who had just finished a one semester…
Daradkeh, T K; Ghubash, R; el-Rufaie, O E
2001-08-01
The aim was to examine the psychometric properties of the Arabic 12-item General Health Questionnaire in a sample of university students. A sample of 157 university students was screened using this questionnaire and the Hopkins Symptom Checklist-90. A standardized clinical interview using SCID was conducted on a subset of screened students. Reliability, validity, and factor analysis of the questionnaire were evaluated. Using factor score discrimination between cases and noncases was also evaluated. The Arabic version of the GHQ-12 proved to be reliable as indicated by Cronbach alpha of .86. The best balance between sensitivity and specificity was found at the General Health Questionnaire cut-off point of 15/16: at this threshold, sensitivity was .88 and was paired with a specificity of .84. Principal component analysis with varimax rotation identified three factors, namely, Factor A (general dysphoria), Factor B (lack of enjoyment), and Factor C (social dysfunction). Factors A and C discriminated between clinically distressed and clinically nondistressed subjects. The General Health Questionnaire-12 as a whole is a reliable and valid screening tool in university settings.
Concurrent validity of the Osteopathic General Surgery In-Service Examination.
Falcone, John L; Rosen, Marc E
2014-04-01
Performance on the Osteopathic General Surgery In-Service Examination (ISE) has been shown to improve over time for osteopathic general surgery residents. The training level-specific concurrent validity of the ISE, however, has not been evaluated. To investigate whether residents' scores will improve as they move from level 1 through level 5 of the ISE. In this retrospective study, performance on the ISE was obtained from the American College of Osteopathic Surgeons for all of the osteopathic general surgery residency programs from 2008 through 2012. The weighted raw score and standardized score performance mean and standard deviation were determined across training levels. One-way t tests were performed between residency years and ISE scores. Parametric statistics were calculated with α set to .05. The authors evaluated 1952 examinations during the study period. Of the 49 programs screened, 33 (67.3%) met inclusion criteria for the present study. Analysis of variance tests showed that there was significant variation in raw and standardized outcomes between residency levels (both Posteopathic general surgery training level. This psychometric characteristic supports the construct validity of this standardized test.
Reformulation of the symmetries of first-order general relativity
Montesinos, Merced; González, Diego; Celada, Mariano; Díaz, Bogar
2017-10-01
We report a new internal gauge symmetry of the n-dimensional Palatini action with cosmological term (n>3 ) that is the generalization of three-dimensional local translations. This symmetry is obtained through the direct application of the converse of Noether’s second theorem on the theory under consideration. We show that diffeomorphisms can be expressed as linear combinations of it and local Lorentz transformations with field-dependent parameters up to terms involving the variational derivatives of the action. As a result, the new internal symmetry together with local Lorentz transformations can be adopted as the fundamental gauge symmetries of general relativity. Although their gauge algebra is open in general, it allows us to recover, without resorting to the equations of motion, the very well-known Lie algebra satisfied by translations and Lorentz transformations in three dimensions. We also report the analog of the new gauge symmetry for the Holst action with cosmological term, finding that it explicitly depends on the Immirzi parameter. The same result concerning its relation to diffeomorphisms and the open character of the gauge algebra also hold in this case. Finally, we consider the non-minimal coupling of a scalar field to gravity in n dimensions and establish that the new gauge symmetry is affected by this matter field. Our results indicate that general relativity in dimension greater than three can be thought of as a gauge theory.
Extent of the Immirzi ambiguity in quantum general relativity
Energy Technology Data Exchange (ETDEWEB)
Marugan, Guillermo A Mena [Centro de Fisica Miguel A Catalan, IMAFF, CSIC, Serrano 121, 28006 Madrid (Spain)
2002-04-21
The Ashtekar-Barbero formulation of general relativity admits a one-parameter family of canonical transformations that preserves the expressions of the Gauss and diffeomorphism constraints. The loop quantization of the connection formalism based on each of these canonical sets leads to different predictions. This phenomenon is called the Immirzi ambiguity. It has been recently argued that this ambiguity could be generalized to the extent of a spatially dependent function instead of a parameter. This would ruin the predictability of loop quantum gravity. We prove that such expectations are not realized, so that the Immirzi ambiguity introduces exclusively a freedom in the choice of a real number. (letter to the edit0008.
Comparison of Einstein-Boltzmann solvers for testing general relativity
Bellini, E.; Barreira, A.; Frusciante, N.; Hu, B.; Peirone, S.; Raveri, M.; Zumalacárregui, M.; Avilez-Lopez, A.; Ballardini, M.; Battye, R. A.; Bolliet, B.; Calabrese, E.; Dirian, Y.; Ferreira, P. G.; Finelli, F.; Huang, Z.; Ivanov, M. M.; Lesgourgues, J.; Li, B.; Lima, N. A.; Pace, F.; Paoletti, D.; Sawicki, I.; Silvestri, A.; Skordis, C.; Umiltà, C.; Vernizzi, F.
2018-01-01
We compare Einstein-Boltzmann solvers that include modifications to general relativity and find that, for a wide range of models and parameters, they agree to a high level of precision. We look at three general purpose codes that primarily model general scalar-tensor theories, three codes that model Jordan-Brans-Dicke (JBD) gravity, a code that models f (R ) gravity, a code that models covariant Galileons, a code that models Hořava-Lifschitz gravity, and two codes that model nonlocal models of gravity. Comparing predictions of the angular power spectrum of the cosmic microwave background and the power spectrum of dark matter for a suite of different models, we find agreement at the subpercent level. This means that this suite of Einstein-Boltzmann solvers is now sufficiently accurate for precision constraints on cosmological and gravitational parameters.
[Development, validity and reliability of a general addiction scale. A preliminary study].
Ramos Brieva, J A; Sansebastián Cabasés, J; Madoz Gurpide, A
2001-01-01
The authors develop a General Scale to measure the intensity of the addiction to substances (not alcohol, not opiates) and addictive behaviors. The General Scale is a self-scale compound by eleven ítems that was delivered to fifty and five students of the courses 5 masculine and 6 masculine of the Medicine of the University of Alcalá (Madrid, Spain), and was them requested that applied said scale from different supposed addictive: tobacco; tea, coffee or cola drinks; chocolate; others sweet; alcohol; sex; use of the personal computer and/or Internet and/or videoplay; and to practice sports. Of that manner, each subject provided a total of 440 complimented scales.Finally, it was requested the subjects that indicated in a scale apart, their degree of addiction from the different exposed concepts. Those data served of external criterion. The Scale is monodimensional, and shows a high construct validity (account 63% of the total variance obtained by a Factorial Analysis), a high alpha reliability (alpha: 0.94) and a good internal consistency (split-half method with the Spearman-Brown correction; R: 0.92). All items share with the general addiction concept that represents the total score of the Scale, an common variance proportion equal or over the 52%. The Scale seems be a valid and reliable instrument to compare groups of the calls new addictions of a measurable manner.
A century of general relativity: astrophysics and cosmology.
Blandford, R D
2015-03-06
One hundred years after its birth, general relativity has become a highly successful physical theory in the sense that it has passed a large number of experimental and observational tests and finds extensive application to a wide variety of cosmic phenomena. It remains an active area of research as new tests are on the way, epitomized by the exciting prospect of detecting gravitational waves from merging black holes. General relativity is the essential foundation of the standard model of cosmology and underlies our description of the black holes and neutron stars that are ultimately responsible for the most powerful and dramatic cosmic sources. Its interface with physics on the smallest and largest scales will continue to provide fertile areas of investigation in its next century. Copyright © 2015, American Association for the Advancement of Science.
Academic Training: Einstein and beyond: Introduction to General relativity
Françoise Benz
2005-01-01
2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 3, 4, 5, 6, 7 October from 11:00 to 12:00 - Main Auditorium, bldg. 500 Einstein and beyond: Introduction to General relativity by N. Straumann / Institut fur theoretische physics, Univ. Zürich We review the enduring achievements of Einstein's papers of 1905 and their impact on the further developments in physics. Program : Lectures I and II:Einstein's Contributions to Statistical Mechanics and Quantum Theory Lecture III:Einstein's Thesis at the University of Zürich Lecture IV: From Special to General Relativity Lecture V: The History and the Mystery of the Cosmological Constant ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch
A 4PN-exact approximation to General Relativity
Brizuela, David
2010-01-01
An approximation to General Relativity is presented which agrees with the Einstein field equations up to and including the fourth post-Newtonian (PN) order. This approximation is formulated in a fully constrained scheme: all involved equations are explicitly elliptic except the wave equation that describes the two independent degrees of freedom of the gravitational field. The formalism covers naturally the conformal-flat-condition (CFC) approach by Isenberg, Wilson, and Mathews and the improved second PN-order exact approach CFC+. For stationary configurations, like Kerr black holes, agreement with General Relativity is achieved even through 5PN order. In addition, we analyze in detail a particularly interesting 2PN-exact waveless approximation which results from imposing more restrictive conditions. The proposed scheme can be considered as a further development on the waveless approach suggested by Schaefer and Gopakumar [Phys. Rev. D {\\bf 69}, 021501 (2004)].
General Theory of Relativity: Will It Survive the Next Decade?
Bertolami, Orfeu; Paramos, Jorge; Turyshev, Slava G.
2006-01-01
The nature of gravity is fundamental to our understanding of our own solar system, the galaxy and the structure and evolution of the Universe. Einstein's general theory of relativity is the standard model that is used for almost ninety years to describe gravitational phenomena on these various scales. We review the foundations of general relativity, discuss the recent progress in the tests of relativistic gravity, and present motivations for high-accuracy gravitational experiments in space. We also summarize the science objectives and technology needs for the laboratory experiments in space with laboratory being the entire solar system. We discuss the advances in our understanding of fundamental physics anticipated in the near future and evaluate discovery potential for the recently proposed gravitational experiments.
Testing General Relativity with the Shadow Size of Sgr A(*).
Johannsen, Tim; Broderick, Avery E; Plewa, Philipp M; Chatzopoulos, Sotiris; Doeleman, Sheperd S; Eisenhauer, Frank; Fish, Vincent L; Genzel, Reinhard; Gerhard, Ortwin; Johnson, Michael D
2016-01-22
In general relativity, the angular radius of the shadow of a black hole is primarily determined by its mass-to-distance ratio and depends only weakly on its spin and inclination. If general relativity is violated, however, the shadow size may also depend strongly on parametric deviations from the Kerr metric. Based on a reconstructed image of Sagittarius A^{*} (Sgr A^{*}) from a simulated one-day observing run of a seven-station Event Horizon Telescope (EHT) array, we employ a Markov chain Monte Carlo algorithm to demonstrate that such an observation can measure the angular radius of the shadow of Sgr A^{*} with an uncertainty of ∼1.5 μas (6%). We show that existing mass and distance measurements can be improved significantly when combined with upcoming EHT measurements of the shadow size and that tight constraints on potential deviations from the Kerr metric can be obtained.
Classical and Quantum Two-Body Problem in General Relativity
Maheshwari, Amar; Todorov, Ivan
2016-01-01
The two-body problem in general relativity is reduced to the problem of an effective particle (with an energy-dependent relativistic reduced mass) in an external field. The effective potential is evaluated from the Born diagram of the linearized quantum theory of gravity. It reduces to a Schwarzschild-like potential with two different `Schwarzschild radii'. The results derived in a weak field approximation are expected to be relevant for relativistic velocities.
Introduction to General Relativity and Black Holes (3/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
Introduction to General Relativity and Black Holes (1/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
Introduction to General Relativity and Black Holes (5/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
Introduction to General Relativity and Black Holes (2/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
Introduction to General Relativity and Black Holes (4/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
Directory of Open Access Journals (Sweden)
Keitly Mensah
2016-08-01
leisure-related sitting-times (r = 0.19. Compared to contextualized logbook, STAQ estimates of TRA was higher for car (r = 0.65 than for active transport (r = 0.41. The questionnaire generally overestimated work- and leisure-related SB and sitting times, while it underestimated total and transport-related sitting times. Conclusions The STAQ showed acceptable reliability and a good ranking validity for assessment of context-specific SB and TRA. This instrument appears as a useful tool to study SB, TRA and PA in context in adults.
Clinical drug trials in general practice: how well are external validity issues reported?
Brænd, Anja Maria; Straand, Jørund; Klovning, Atle
2017-12-29
When reading a report of a clinical trial, it should be possible to judge whether the results are relevant for your patients. Issues affecting the external validity or generalizability of a trial should therefore be reported. Our aim was to determine whether articles with published results from a complete cohort of drug trials conducted entirely or partly in general practice reported sufficient information about the trials to consider the external validity. A cohort of 196 drug trials in Norwegian general practice was previously identified from the Norwegian Medicines Agency archive with year of application for approval 1998-2007. After comprehensive literature searches, 134 journal articles reporting results published from 2000 to 2015 were identified. In these articles, we considered the reporting of the following issues relevant for external validity: reporting of the clinical setting; selection of patients before inclusion in a trial; reporting of patients' co-morbidity, co-medication or ethnicity; choice of primary outcome; and reporting of adverse events. Of these 134 articles, only 30 (22%) reported the clinical setting of the trial. The number of patients screened before enrolment was reported in 61 articles (46%). The primary outcome of the trial was a surrogate outcome for 60 trials (45%), a clinical outcome for 39 (29%) and a patient-reported outcome for 25 (19%). Clinical details of adverse events were reported in 124 (93%) articles. Co-morbidity of included participants was reported in 54 trials (40%), co-medication in 27 (20%) and race/ethnicity in 78 (58%). The clinical setting of the trials, the selection of patients before enrolment, and co-morbidity or co-medication of participants was most commonly not reported, limiting the possibility to consider the generalizability of a trial. It may therefore be difficult for readers to judge whether drug trial results are applicable to clinical decision-making in general practice or when developing clinical
General relativity from three-forms in seven dimensions
Directory of Open Access Journals (Sweden)
Kirill Krasnov
2017-09-01
Full Text Available We consider a certain theory of 3-forms in 7 dimensions, and study its dimensional reduction to 4D, compactifying the 7-dimensional manifold on the 3-sphere of a fixed radius. We show that the resulting 4D theory is (Riemannian General Relativity (GR in Plebanski formulation, modulo corrections that are negligible for curvatures smaller than Planckian. Possibly the most interesting point of this construction is that the dimensionally reduced theory is GR with a non-zero cosmological constant, and the value of the cosmological constant is directly related to the size of S3. Realistic values of Λ correspond to S3 of Planck size.
Explanatory and illustrative visualization of special and general relativity.
Weiskopf, Daniel; Borchers, Marc; Ertl, Thomas; Falk, Martin; Fechtig, Oliver; Frank, Regine; Grave, Frank; King, Andreas; Kraus, Ute; Müller, Thomas; Nollert, Hans-Peter; Rica Mendez, Isabel; Ruder, Hanns; Schafhitzel, Tobias; Schär, Sonja; Zahn, Corvin; Zatloukal, Michael
2006-01-01
This paper describes methods for explanatory and illustrative visualizations used to communicate aspects of Einstein's theories of special and general relativity, their geometric structure, and of the related fields of cosmology and astrophysics. Our illustrations target a general audience of laypersons interested in relativity. We discuss visualization strategies, motivated by physics education and the didactics of mathematics, and describe what kind of visualization methods have proven to be useful for different types of media, such as still images in popular science magazines, film contributions to TV shows, oral presentations, or interactive museum installations. Our primary approach is to adopt an egocentric point of view: The recipients of a visualization participate in a visually enriched thought experiment that allows them to experience or explore a relativistic scenario. In addition, we often combine egocentric visualizations with more abstract illustrations based on an outside view in order to provide several presentations of the same phenomenon. Although our visualization tools often build upon existing methods and implementations, the underlying techniques have been improved by several novel technical contributions like image-based special relativistic rendering on GPUs, special relativistic 4D ray tracing for accelerating scene objects, an extension of general relativistic ray tracing to manifolds described by multiple charts, GPU-based interactive visualization of gravitational light deflection, as well as planetary terrain rendering. The usefulness and effectiveness of our visualizations are demonstrated by reporting on experiences with, and feedback from, recipients of visualizations and collaborators.
Gravitation experiments at Stanford. [using general relativity theory
Lipa, J. A.
1980-01-01
The experimental situation in post-Newtonian gravitation is briefly reviewed in order to reexamine the extent to which experiment supports or refutes general relativity. A description is given of the equivalence principle project, the gyroscope experiment, and the search for gravity waves. It is noted that even though some doubt has been cast on the value of the perihelion advance and the gravitational redshift as precise tests of general relativity in the past few years, many competing theories have been ruled out; in particular, the results from the Viking mission significantly reduce the credibility of the Brans-Dicke theory (Brans and Dicke, 1961). The dimensionless constant omega in this theory is now forced to exceed 50, while the value originally proposed was 6 (omega being infinity in general relativity). It is noted that the gyro experiment described is capable of putting much tighter limits on this parameter, and together with the other experiments in progress will help place gravitational theory on a firmer experimental footing.
Directory of Open Access Journals (Sweden)
Norma Rodríguez
2016-12-01
Full Text Available Several socioeconomic factors are associated with poor oral hygiene habits. A version of the Oral Hygiene Habits Scale (OHHS was developed in Mexico to measure these factors; however, its relationship with sociodemographic variables has not been studied. The verification of these relationships could contribute to the validation of the scale. Objective: To evaluate the relationship between oral hygiene habits and sociodemographic variables of sex, age, schooling, self-defined socioeconomic stratum, occupation and marital status in the general and clinical population of Monterrey, Mexico. Materials and Methods: A general population sample (GPS of 256 participants and a clinical sample (CPS of 240 participants were studied. The OHHS consisted of an eight-item Likert scale of 4 points ranging from 0 to 4. A descriptive correlational study was performed with a cross-sectional design. Data were analyzed using the Mann-Whitney U test, Kruskal-Wallis test, Spearman correlation coefficient, Cramer's V coefficient, and multivariate aligned rank test. Results: In GPS and CPS groups, OHHS was related to sex, schooling, socioeconomic stratum, occupation and marital status, but not to age. There were no significant interactions between the samples (GPS and CPS and sociodemographic variables. Conclusion: There is a statistically significant relationship between oral hygiene habits and some sociodemographic variables in the general and clinical population. This relationship supports the validity of the OHHS.
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.
Peláez-Fernández, María Angeles; Ruiz-Lázaro, Pedro Manuel; Labrador, Francisco Javier; Raich, Rosa María
2014-02-20
To validate the best cut-off point of the Eating Attitudes Test (EAT-40), Spanish version, for the screening of eating disorders (ED) in the general population. This was a transversal cross-sectional study. The EAT-40 Spanish version was administered to a representative sample of 1.543 students, age range 12 to 21 years, in the Region of Madrid. Six hundred and two participants (probable cases and a random sample of controls) were interviewed. The best diagnostic prediction was obtained with a cut-off point of 21, with sensitivity: 88.2%; specificity: 62.1%; positive predictive value: 17.7%; negative predictive value: 62.1%. Use of a cut-off point of 21 is recommended in epidemiological studies of eating disorders in the Spanish general population. Copyright © 2012 Elsevier España, S.L. All rights reserved.
Verification and Validation of a Three-Dimensional Generalized Composite Material Model
Hoffarth, Canio; Harrington, Joseph; Rajan, Subramaniam D.; Goldberg, Robert K.; Carney, Kelly S.; DuBois, Paul; Blankenhorn, Gunther
2015-01-01
A general purpose orthotropic elasto-plastic computational constitutive material model has been developed to improve predictions of the response of composites subjected to high velocity impact. The three-dimensional orthotropic elasto-plastic composite material model is being implemented initially for solid elements in LS-DYNA as MAT213. In order to accurately represent the response of a composite, experimental stress-strain curves are utilized as input, allowing for a more general material model that can be used on a variety of composite applications. The theoretical details are discussed in a companion paper. This paper documents the implementation, verification and qualitative validation of the material model using the T800-F3900 fiber/resin composite material
Relative validity and reliability of a quantitative food frequency questionnaire for adults in Guam
Directory of Open Access Journals (Sweden)
Rachael T. Leon Guerrero
2015-05-01
Full Text Available Background: Guam is a US territory in the western Pacific with a diverse population that includes understudied ethnic groups such as Chamorros and Filipinos. A food frequency questionnaire (FFQ to estimate dietary intake was needed to facilitate studies of diet and health among adults living in Guam. Objective: To develop and validate an FFQ to assess dietary intake over a 1-year period among adult Guam residents. Design: A three-part study was conducted: 1 an initial cross-sectional study using 24-h recalls to identify a food and beverage list for the FFQ and resulting in a final FFQ containing 142 food and drink items; 2 to test reliability, 56 different individuals completed the FFQ twice; and 3 to test relative validity, self-administered FFQs and up to 2 days of food record data from an additional 109 individuals were collected, and daily nutrient intake from the two methods was compared. Results: The reliability of the FFQ was very good (ρ range=0.65–0.75, and the relative validity of the FFQ was good for women (median Spearman's correlation [ρ] between instruments of 0.45 across 20 nutrients and an interquartile range [IQR] of 0.42–0.58 and generally adequate for men (median ρ=0.31, IQR=0.23–0.55. Validity was also good for Chamorros (median ρ=0.47, IQR=0.38–0.53 and generally adequate for Filipinos (median ρ=0.42, IQR=0.20–0.62. Correlations after energy adjustment were lower (overall median ρ=0.20, IQR=0.14–0.26. Conclusions: The FFQ can be used to rank nutrient intake for adults in Guam and may be helpful in the analysis of relationships between diet and chronic disease in Guam.
A New Generalization of von Neumann Relative Entropy
Li, Jing; Cao, Huaixin
2017-11-01
In quantum information, von Neumann relative entropy has a great applications and operational interpretations in diverse fields, and von Neumann entropy is an important tool for describing the uncertainty of a quantum state. In this paper, we generalize the classical von Neumann relative entropy S( ρ|| σ) and von Neumann entropy S( ρ) to f-von Neumann relative entropy \\widetilde {S}f(ρ ||σ ) and f-von Neumann entropy \\widetilde {S}f(ρ ) induced by a logarithm-like function f, respectively, and explore their properties. We prove that \\widetilde {S}f(ρ ||σ ) is nonnegative and then prove that \\widetilde {S}f(ρ ) has nonnegativity, boundedness, concavity, subadditivity and so on. Later, we show the stability and continuity of the \\widetilde {S}f(ρ ) with respect to the trace distance. In the case that f( x) = -log x, the resulted entropies reduce the classical von Neumann relative entropy and von Neumann entropy, respectively. This means that our results extend the usual results to a more general setting and then have some potential applications in quantum information.
The Pain-Related Cognitive Processes Questionnaire: Development and Validation.
Day, Melissa A; Ward, L Charles; Thorn, Beverly E; Lang, Cathryne P; Newton-John, Toby R O; Ehde, Dawn M; Jensen, Mark P
2017-03-06
Cognitive processes may be characterized as how individuals think, whereas cognitive content constitutes what individuals think. Both cognitive processes and cognitive content are theorized to play important roles in chronic pain adjustment, and treatments have been developed to target both. However, the evaluation of treatments that target cognitive processes is limited because extant measures do not satisfactorily separate cognitive process from cognitive content. The current study aimed to develop a self-report inventory of potentially adaptive and presumed maladaptive attentional processes that may occur when someone is experiencing pain. Scales were derived from a large item pool by successively applying confirmatory factor analysis to item data from two undergraduate samples (N = 393 and 233). Items, which were generated to avoid confounding of cognitive content with cognitive processes, represented nine constructs: Suppression, Distraction, Enhancement, Dissociation, Reappraisal, Absorption, Rumination, Nonjudgment, and Acceptance. The resulting nine scales formed the Pain-Related Cognitive Process Questionnaire (PCPQ), and scale correlations produced four conceptually distinct composite scales: Pain Diversion, Pain Distancing, Pain Focus, and Pain Openness. Internal consistency reliabilities of the nine scales were adequate (α ≥ 0.70) to good, and the four composite scales had α values of 0.79 or higher. Correlations with pain-related criterion variables were generally consistent with putative constructs. The developed PCPQ scales offer a comprehensive assessment of important cognitive processes specific to pain. Overall, the findings suggest that the PCPQ scales may prove useful for evaluating the role of pain-related cognitive processes in studies of chronic pain.
Testing general relativity using golden black-hole binaries
Ghosh, Abhirup; Johnson-McDaniel, Nathan K; Mishra, Chandra Kant; Ajith, Parameswaran; Del Pozzo, Walter; Nichols, David A; Chen, Yanbei; Nielsen, Alex B; Berry, Christopher P L; London, Lionel
2016-01-01
The coalescences of stellar-mass black-hole binaries through their inspiral, merger, and ringdown are among the most promising sources for ground-based gravitational-wave (GW) detectors. If a GW signal is observed with sufficient signal-to-noise ratio, the masses and spins of the black holes can be estimated from just the inspiral part of the signal. Using these estimates of the initial parameters of the binary, the mass and spin of the final black hole can be uniquely predicted making use of general-relativistic numerical simulations. In addition, the mass and spin of the final black hole can be independently estimated from the merger-ringdown part of the signal. If the binary black hole dynamics is correctly described by general relativity, these independent estimates have to be consistent with each other. We present a Bayesian implementation of such a test of general relativity, and outline the expected constraints from upcoming GW observations using the second-generation of ground-based GW detectors.
Standard general relativity from Chern-Simons gravity
Energy Technology Data Exchange (ETDEWEB)
Izaurieta, F. [Departamento de Matematica y Fisica Aplicadas, Universidad, Catolica de la Santisima Concepcion, Alonso de Rivera 2850, Concepcion (Chile); Minning, P. [Departamento de Fisica, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile); Perez, A. [Departamento de Fisica, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile); Max Planck Institut fuer Gravitationsphysik, Albert Einstein, Institut. Am Muehlenberg1, D-14476 Golm bei Potsdam (Germany); Rodriguez, E. [Departamento de Matematica y Fisica Aplicadas, Universidad, Catolica de la Santisima Concepcion, Alonso de Rivera 2850, Concepcion (Chile); Salgado, P. [Departamento de Fisica, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile)], E-mail: pasalgad@udec.cl
2009-07-13
Chern-Simons models for gravity are interesting because they provide a truly gauge-invariant action principle in the fiber-bundle sense. So far, their main drawback has largely been its perceived remoteness from standard General Relativity, based on the presence of higher powers of the curvature in the Lagrangian (except, remarkably, for three-dimensional spacetime). Here we report on a simple model that suggests a mechanism by which standard General Relativity in five-dimensional spacetime may indeed emerge at a special critical point in the space of couplings, where additional degrees of freedom and corresponding 'anomalous' Gauss-Bonnet constraints drop out from the Chern-Simons action. To achieve this goal, both the Lie algebra g and the symmetric g-invariant tensor that define the Chern-Simons Lagrangian are constructed by means of the Lie algebra S-expansion method with a suitable finite Abelian semigroup S. The results are generalized to arbitrary odd dimensions, and the possible extension to the case of eleven-dimensional supergravity is briefly discussed.
Physical constraints on causality-violating spacetimes in general relativity
Janca, Andrew Joseph
The theoretical possibility of global causality violation has long been a problem within general relativity, for there exists a large number of model spacetimes known to admit closed time-like curves, trajectories allowing a timelike observer to return to some point in her own past. However, nearly all such known models have some unphysical feature. These physicality issues rendered causality-violation to the status of an interesting but safely theoretical problem until twenty years ago, when the appearance of a new type of causality-violating model spacetime and the subsequent proliferation of new models admitting closed timelike curves forced the attention of the community to the issue, and made causality violation and its possible physical consequences an active area of research within general relativity. This paper focuses on some of the older causality-violating spacetimes which model matter sources with cylindrical symmetry. By describing how cylindrically-symmetric solutions can be embedded within a spatially bounded and physically realistic body which outwardly has the symmetry of a torus or ring, it is shown that the chief problem of physical plausibility which these older solutions possess can be resolved. The intention is to make these models active candidates for consideration in future experiments to test general relativity's prediction that causality violation is a phenomenon that could be observed in the real world. Attending chapters describe physical systems other than rotating objects that can alter a local observer's experience of time to a substantial extent, including an electrically-charged massive shell slowing time in its interior (though not affecting causality) and a class of trajectories in the Reissner-Nordstrom background that could in principle allow a timelike observer to reverse her personal arrow of time relative to other observers in the spacetime as a whole. The paper concludes with a discussion of one of the plausibility problems
Kramer, A.W.M.; Jansen, J.J.; Zuithoff, P.; Dusman, H.; Tan, L.; Grol, R.P.T.M.; Vleuten, C.P.M. van der
2002-01-01
PURPOSE: To examine the validity of a written knowledge test of skills for performance on an OSCE in postgraduate training for general practice. METHODS: A randomly-selected sample of 47 trainees in general practice took a knowledge test of skills, a general knowledge test and an OSCE. The OSCE
Comment on "Construction of regular black holes in general relativity"
Bronnikov, Kirill A.
2017-12-01
We claim that the paper by Zhong-Ying Fan and Xiaobao Wang on nonlinear electrodynamics coupled to general relativity [Phys. Rev. D 94,124027 (2016)], although correct in general, in some respects repeats previously obtained results without giving proper references. There is also an important point missing in this paper, which is necessary for understanding the physics of the system: in solutions with an electric charge, a regular center requires a non-Maxwell behavior of Lagrangian function L (f ) , (f =Fμ νFμ ν) at small f . Therefore, in all electric regular black hole solutions with a Reissner-Nordström asymptotic, the Lagrangian L (f ) is different in different parts of space, and the electromagnetic field behaves in a singular way at surfaces where L (f ) suffers branching.
Boundary and Corner Terms in the Action for General Relativity
Jubb, Ian; Sorkin, Rafael; Surya, Sumati
2016-01-01
We revisit the action principle for general relativity motivated by the path integral approach to quantum gravity. We consider a spacetime region whose boundary has piecewise $C^2$ components, each of which can be spacelike, timelike or null and consider metric variations in which only the pullback of the metric to the boundary is held fixed. Allowing all such metric variations we present a unified treatment of the spacelike, timelike and null boundary components using Cartan's tetrad formalism. Apart from its computational simplicity, this formalism gives us a simple way of identifying corner terms. We also discuss "creases" which occur when the boundary is the event horizon of a black hole. Our treatment is geometric and intrinsic and we present our results both in the computationally simpler tetrad formalism as well as the more familiar metric formalism. We recover known results from a simpler and more general point of view and find some new ones.
Hoffman, Brian J; Kennedy, Colby L; LoPilato, Alexander C; Monahan, Elizabeth L; Lance, Charles E
2015-07-01
This study uses meta-analysis and a qualitative review of exercise descriptions to evaluate the content, criterion-related, construct, and incremental validity of 5 commonly used types of assessment center (AC) exercises. First, we present a meta-analysis of the relationship between 5 types of AC exercises with (a) the other exercise types, (b) the 5-factor model of personality, (c) general mental ability (GMA), and (d) relevant criterion variables. All 5 types of exercises were significantly related to criterion variables (ρ = .16-.19). The nomological network analyses suggested that the exercises tend to be modestly associated with GMA, Extraversion and, to a lesser extent, Openness to Experience but largely unrelated to Agreeableness, Conscientiousness, and Emotional Stability. Finally, despite sparse reporting in primary studies, a content analysis of exercise descriptions yielded some evidence of complexity, ambiguity, interpersonal interaction, and fidelity but not necessarily interdependence. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
Directory of Open Access Journals (Sweden)
Pace Fabio
2006-11-01
Full Text Available Abstract Background The PGWBI is a 22-item health-related Quality of Life (HRQoL questionnaire developed in US which produces a self-perceived evaluation of psychological well-being expressed by a summary score. The PGWBI has been validated and used in many countries on large samples of the general population and on specific patient groups. Recently a study was carried out in Italy to reduce the number of items of the original questionnaire, yielding the creation of a shorter validated version of the questionnaire (PGWB-S. The purpose of the present paper is to describe the methods adopted and to report and discuss the relevance of results. Methods Data for this study were collected from 4 different population samples: two general population samples a student and a patient sample. On the basis of the results of the first (development sample population, six relevant items were identified statistically from the original questionnaire and grouped to assemble a new summary scale. Following the newly created 6-item questionnaire was administered in three independent population samples. Descriptive statistics, correlation coefficients, univariate and multivariate regression analyses were used to compare the performance of the long and short questionnaire, within and between population samples and across relevant subgroups. A further independent sample extracted by an ongoing cancer clinical trial served as final validation step. Results Overall, the questionnaires were administered to 1443 subjects. Six items were selected by a step-wise approach to explain 90% of the variance of the summary measure of the original questionnaire. Response rates reached 100%, while missing items were not observed. University students (n = 400 showed the highest mean value of the summary measure (75.3; while the patient sample (n = 28 had the lowest score (71.5. The correlation coefficients between the summary measures and the single items according to the different
Further summation formulae related to generalized harmonic numbers
Zheng, De-Yin
2007-11-01
By employing the univariate series expansion of classical hypergeometric series formulae, Shen [L.-C. Shen, Remarks on some integrals and series involving the Stirling numbers and [zeta](n), Trans. Amer. Math. Soc. 347 (1995) 1391-1399] and Choi and Srivastava [J. Choi, H.M. Srivastava, Certain classes of infinite series, Monatsh. Math. 127 (1999) 15-25; J. Choi, H.M. Srivastava, Explicit evaluation of Euler and related sums, Ramanujan J. 10 (2005) 51-70] investigated the evaluation of infinite series related to generalized harmonic numbers. More summation formulae have systematically been derived by Chu [W. Chu, Hypergeometric series and the Riemann Zeta function, Acta Arith. 82 (1997) 103-118], who developed fully this approach to the multivariate case. The present paper will explore the hypergeometric series method further and establish numerous summation formulae expressing infinite series related to generalized harmonic numbers in terms of the Riemann Zeta function [zeta](m) with m=5,6,7, including several known ones as examples.
The revival of General Relativity at Princeton: Daring Conservatism
Brill, Dieter; Blum, Alexander
2018-01-01
After General Relativity was established in essentially its present form in 1915 it was celebrated as a great success of mathematical physics. But the initial hopes for this theory as a basis for all of physics began to fade in the next several decades, as General Relativity was relegated to the margins of theoretical physics. Its fate began to rise in the 1950's in a revival of interest and research that over time made gravitational physics one of the hottest research topics it is today. One center of this renaissance was Princeton, where two relative newcomers explored new and different approaches to gravitational physics. Robert Dicke showed that gravity is not as inaccessible to experiment as was thought, and John Wheeler propelled it into the mainstream by proposing highly original and imaginative consequences of Einstein's theory. We will concentrate on these ideas that, in his characteristically intriguing style, Wheeler called "Daring Conservatism" - a term well known to his associates, but one he never mentioned in print. With the aid of unpublished manuscripts and notes we will explore Daring Conservatism's origin and motivation, its successes and failures, and the legacy it left behind.
Bitopological spaces theory, relations with generalized algebraic structures and applications
Dvalishvili, Badri
2005-01-01
This monograph is the first and an initial introduction to the theory of bitopological spaces and its applications. In particular, different families of subsets of bitopological spaces are introduced and various relations between two topologies are analyzed on one and the same set; the theory of dimension of bitopological spaces and the theory of Baire bitopological spaces are constructed, and various classes of mappings of bitopological spaces are studied. The previously known results as well the results obtained in this monograph are applied in analysis, potential theory, general topology, a
General Video Game Evaluation Using Relative Algorithm Performance Profiles
DEFF Research Database (Denmark)
Nielsen, Thorbjørn; Barros, Gabriella; Togelius, Julian
2015-01-01
In order to generate complete games through evolution we need generic and reliably evaluation functions for games. It has been suggested that game quality could be characterised through playing a game with different controllers and comparing their performance. This paper explores that idea through...... investigating the relative performance of different general game-playing algorithms. Seven game-playing algorithms was used to play several hand-designed, mutated and randomly generated VGDL game descriptions. Results discussed appear to support the conjecture that well-designed games have, in average, a higher...... performance difference between better and worse game-playing algorithms....
Evolving black hole horizons in General Relativity and alternative gravity
Faraoni, Valerio
2013-01-01
From the microscopic point of view, realistic black holes are time-dependent and the teleological concept of event horizon fails. At present, the apparent or the trapping horizon seem its best replacements in various areas of black hole physics. We discuss the known phenomenology of apparent and trapping horizons for analytical solutions of General Relativity and alternative theories of gravity. These specific examples (we focus on spherically symmetric inhomogeneities in a background cosmological spacetime) may be useful as toy models for research on various aspects of black hole physics.
A superconducting gyroscope to test Einstein's general theory of relativity
Everitt, C. W. F.
1978-01-01
Schiff (1960) proposed a new test of general relativity based on measuring the precessions of the spin axes of gyroscopes in earth orbit. Since 1963 a Stanford research team has been developing an experiment to measure the two effects calculated by Schiff. The gyroscope consists of a uniform sphere of fused quartz 38 mm in diameter, coated with superconductor, electrically suspended and spinning at about 170 Hz in vacuum. The paper describes the proposed flight apparatus and the current state of development of the gyroscope, including techniques for manufacturing and measuring the gyro rotor and housing, generating ultralow magnetic fields, and mechanizing the readout.
Evolving Black Hole Horizons in General Relativity and Alternative Gravity
Directory of Open Access Journals (Sweden)
Valerio Faraoni
2013-09-01
Full Text Available From the microscopic point of view, realistic black holes are time-dependent and the teleological concept of the event horizon fails. At present, the apparent or trapping horizon seem to be its best replacements in various areas of black hole physics. We discuss the known phenomenology of apparent and trapping horizons for analytical solutions of General Relativity and alternative theories of gravity. These specific examples (we focus on spherically symmetric inhomogeneities in a background cosmological spacetime are useful as toy models for research on various aspects of black hole physics.
Criterion-related validity of screening for exposure to torture
DEFF Research Database (Denmark)
Montgomery, Edith; Foldspang, Anders
1994-01-01
Using an in-depth psychological assessment as reference, the aim of the study was to validate adult Middle Eastern refugees' own testimonies of their possible previous exposure to torture. The study group comprised 31 male and 43 female refugees, who accepted participation in a structured interview......%, respectively, without significant differences concerning the refugee's gender. It is concluded that refugees' own testimonies of torture appear fairly valid. This enables anamnestic torture prevalence estimation in refugee groups, based on pre-structured interview techniques. Rehabilitation and Research Centre...
Kerr-Taub-NUT General Frame, Energy, and Momentum in Teleparallel Equivalent of General Relativity
Directory of Open Access Journals (Sweden)
Gamal G. L. Nashed
2012-01-01
Full Text Available A new exact solution describing a general stationary and axisymmetric object of the gravitational field in the framework of teleparallel equivalent of general relativity (TEGR is derived. The solution is characterized by three parameters “the gravitational mass M, the rotation a, and the NUT L.” The vierbein field is axially symmetric, and the associated metric gives the Kerr-Taub-NUT spacetime. Calculation of the total energy using two different methods, the gravitational energy momentum and the Riemannian connection 1-form Γα̃β, is carried out. It is shown that the two methods give the same results of energy and momentum. The value of energy is shown to depend on the mass M and the NUT parameter L. If L is vanishing, then the total energy reduced to the energy of Kerr black hole.
Gyroscope precession in special and general relativity from basic principles
Jonsson, Rickard M.
2007-05-01
In special relativity a gyroscope that is suspended in a torque-free manner will precess as it is moved along a curved path relative to an inertial frame S. We explain this effect, which is known as Thomas precession, by considering a real grid that moves along with the gyroscope, and that by definition is not rotating as observed from its own momentary inertial rest frame. From the basic properties of the Lorentz transformation we deduce how the form and rotation of the grid (and hence the gyroscope) will evolve relative to S. As an intermediate step we consider how the grid would appear if it were not length contracted along the direction of motion. We show that the uncontracted grid obeys a simple law of rotation. This law simplifies the analysis of spin precession compared to more traditional approaches based on Fermi transport. We also consider gyroscope precession relative to an accelerated reference frame and show that there are extra precession effects that can be explained in a way analogous to the Thomas precession. Although fully relativistically correct, the entire analysis is carried out using three-vectors. By using the equivalence principle the formalism can also be applied to static spacetimes in general relativity. As an example, we calculate the precession of a gyroscope orbiting a static black hole.
Poisson, Eric
2010-05-01
A few years ago, in my review of Sean Carroll's book in Classical and Quantum Gravity [1], I wrote that while the 1970s was the decade of Weinberg [2] and Misner, Thorne and Wheeler [3], and while the eighties was the decade of Schutz [4] and Wald [5], the 2000s was clearly the decade of Hartle [6] and Carroll [7]. In my opinion, these books continue to stand out in the surprisingly dense crowd of introductory textbooks on general relativity. At the dawn of this new decade I look forward to see what fresh pedagogical insights will be produced next, and who will be revealed as the winners of the 2010s. It is, of course, much too early to tell, but Schutz is back, and he will set the standard just as he did back in 1985. This is the long-awaited second edition of his `First Course', a short, accessible, and very successful introduction to general relativity. The changes from the first edition are modest: Schutz wisely refrained from bloating the text with new topics, and limited himself to updating his discussion of gravitational-wave sources and detectors, neutron-star and black-hole astrophysics, and suggestions for further reading. Most importantly, he completely rewrote the chapter on cosmology, a topic that has evolved enormously since the first edition. The book begins in chapter 1 with a beautiful review of special relativity that emphasizes spacetime geometry and stays away from an algebraic approach based on the Lorentz transformation, which appears only later in the chapter. This is followed up in chapters 2 and 3 with an introduction to vector and tensor analysis in flat spacetime. The point of view is modern (tensors are defined as linear mapping of vectors and one-forms into real numbers) but the presentation is very accessible and avoids an overload of mathematical fine print. In chapter 4 the book introduces the spacetime description of fluids; it is here that the energy-momentum tensor makes its first appearance. The move to curved spacetime is
Theory of Nonlocal Point Transformations in General Relativity
Directory of Open Access Journals (Sweden)
Massimo Tessarotto
2016-01-01
Full Text Available A discussion of the functional setting customarily adopted in General Relativity (GR is proposed. This is based on the introduction of the notion of nonlocal point transformations (NLPTs. While allowing the extension of the traditional concept of GR-reference frame, NLPTs are important because they permit the explicit determination of the map between intrinsically different and generally curved space-times expressed in arbitrary coordinate systems. For this purpose in the paper the mathematical foundations of NLPT-theory are laid down and basic physical implications are considered. In particular, explicit applications of the theory are proposed, which concern (1 a solution to the so-called Einstein teleparallel problem in the framework of NLPT-theory; (2 the determination of the tensor transformation laws holding for the acceleration 4-tensor with respect to the group of NLPTs and the identification of NLPT-acceleration effects, namely, the relationship established via general NLPT between particle 4-acceleration tensors existing in different curved space-times; (3 the construction of the nonlocal transformation law connecting different diagonal metric tensors solution to the Einstein field equations; and (4 the diagonalization of nondiagonal metric tensors.
Einstein and Beyond: A Critical Perspective on General Relativity
Directory of Open Access Journals (Sweden)
Ram Gopal Vishwakarma
2016-05-01
Full Text Available An alternative approach to Einstein’s theory of General Relativity (GR is reviewed, which is motivated by a range of serious theoretical issues inflicting the theory, such as the cosmological constant problem, presence of non-Machian solutions, problems related with the energy-stress tensor T i k and unphysical solutions. The new approach emanates from a critical analysis of these problems, providing a novel insight that the matter fields, together with the ensuing gravitational field, are already present inherently in the spacetime without taking recourse to T i k . Supported by lots of evidence, the new insight revolutionizes our views on the representation of the source of gravitation and establishes the spacetime itself as the source, which becomes crucial for understanding the unresolved issues in a unified manner. This leads to a new paradigm in GR by establishing equation R i k = 0 as the field equation of gravitation plus inertia in the very presence of matter.
The problem of time quantum mechanics versus general relativity
Anderson, Edward
2017-01-01
This book is a treatise on time and on background independence in physics. It first considers how time is conceived of in each accepted paradigm of physics: Newtonian, special relativity, quantum mechanics (QM) and general relativity (GR). Substantial differences are moreover uncovered between what is meant by time in QM and in GR. These differences jointly source the Problem of Time: Nine interlinked facets which arise upon attempting concurrent treatment of the QM and GR paradigms, as is required in particular for a background independent theory of quantum gravity. A sizeable proportion of current quantum gravity programs - e.g. geometrodynamical and loop quantum gravity approaches to quantum GR, quantum cosmology, supergravity and M-theory - are background independent in this sense. This book's foundational topic is thus furthermore of practical relevance in the ongoing development of quantum gravity programs. This book shows moreover that eight of the nine facets of the Problem of Time already occur upon ...
Factors Related to the Validity of Reproduction Tonal Memory Tests.
Norris, Charles E.
2000-01-01
Explores the validity of reproduction tonal memory tests by examining the relationships among performances on an existing reproduction tonal memory test and several recognition tonal memory tests. Tested 210 fifth through twelfth grade students. Concludes that there is a moderate relationship among performances on the tests. Includes references.…
Fixing extensions to general relativity in the nonlinear regime
Cayuso, Juan; Ortiz, Néstor; Lehner, Luis
2017-10-01
The question of what gravitational theory could supersede General Relativity has been central in theoretical physics for decades. Many disparate alternatives have been proposed motivated by cosmology, quantum gravity and phenomenological angles, and have been subjected to tests derived from cosmological, solar system and pulsar observations typically restricted to linearized regimes. Gravitational waves from compact binaries provide new opportunities to probe these theories in the strongly gravitating/highly dynamical regimes. To this end however, a reliable understanding of the dynamics in such a regime is required. Unfortunately, most of these theories fail to define well posed initial value problems, which prevents at face value from meeting such challenge. In this work, we introduce a consistent program able to remedy this situation. This program is inspired in the approach to "fixing" viscous relativistic hydrodynamics introduced by Israel and Stewart in the late 70's. We illustrate how to implement this approach to control undesirable effects of higher order derivatives in gravity theories and argue how the modified system still captures the true dynamics of the putative underlying theories in 3 +1 dimensions. We sketch the implementation of this idea in a couple of effective theories of gravity, one in the context of Noncommutative Geometry, and one in the context of Chern-Simons modified General Relativity.
New Probe of Departures from General Relativity Using Minkowski Functionals.
Fang, Wenjuan; Li, Baojiu; Zhao, Gong-Bo
2017-05-05
The morphological properties of the large scale structure of the Universe can be fully described by four Minkowski functionals (MFs), which provide important complementary information to other statistical observables such as the widely used 2-point statistics in configuration and Fourier spaces. In this work, for the first time, we present the differences in the morphology of the large scale structure caused by modifications to general relativity (to address the cosmic acceleration problem), by measuring the MFs from N-body simulations of modified gravity and general relativity. We find strong statistical power when using the MFs to constrain modified theories of gravity: with a galaxy survey that has survey volume ∼0.125(h^{-1} Gpc)^{3} and galaxy number density ∼1/(h^{-1} Mpc)^{3}, the two normal-branch Dvali-Gabadadze-Porrati models and the F5 f(R) model that we simulated can be discriminated from the ΛCDM model at a significance level ≳5σ with an individual MF measurement. Therefore, the MF of the large scale structure is potentially a powerful probe of gravity, and its application to real data deserves active exploration.
Hospital Anxiety and Depression Scale (HADS: validation in a Greek general hospital sample
Directory of Open Access Journals (Sweden)
Patapis Paulos
2008-03-01
Full Text Available Abstract Background The Hospital Anxiety and Depression Scale (HADS has been used in several languages to assess anxiety and depression in general hospital patients with good results. Methods The HADS was administered to 521 participants (275 controls and 246 inpatients and outpatients of the Internal Medicine and Surgical Departments in 'Attikon' General Hospital in Athens. The Beck Depression Inventory (BDI and the State-Trait Anxiety Inventory (STAI were used as 'gold standards' for depression and anxiety respectively. Results The HADS presented high internal consistency; Cronbach's α cofficient was 0.884 (0.829 for anxiety and 0.840 for depression and stability (test-retest intraclass correlation coefficient 0.944. Factor analysis showed a two-factor structure. The HADS showed high concurrent validity; the correlations of the scale and its subscales with the BDI and the STAI were high (0.722 – 0.749. Conclusion The Greek version of HADS showed good psychometric properties and could serve as a useful tool for clinicians to assess anxiety and depression in general hospital patients.
Solar energy utilization by a greenhouse: General relations
Energy Technology Data Exchange (ETDEWEB)
Abdel-Ghany, A.M.; Al-Helal, I.M. [Department of Agricultural Engineering, College of Food and Agriculture Sciences, King Saud University, PO box 2460, Riyadh 11451 (Saudi Arabia)
2011-01-15
Most of solar radiation incident on a greenhouse is absorbed by greenhouse components (i.e., the cover, humid air, plants and soil) and the remaining portion is lost to outside the greenhouse. It is essential to know the absorbed and lost energy terms for any thermal analysis of greenhouses. Existing greenhouse thermal models use the radiative properties of the greenhouse components to directly determine the absorbed energy terms. However, these models neglect the lost energy term and neglect the effects of the multiple reflections of solar radiation between the greenhouse components. The present study describes the general relations for estimating the amounts of solar energy absorbed by the greenhouse components and lost to outside the greenhouse. The relations take into consideration the interrelations as well as the multiple reflections of solar radiation between these components. Thus, the greenhouse system was treated as a solar collector having an absorber plate (i.e., the greenhouse soil) and a cover system consisting of three semi-transparent parallel layers (i.e., the greenhouse cover, the humid air, and the plants). Superposition theory and ray tracing technique were used for the analysis. The presented relations were applied to an experimental plastic-covered greenhouse with a floor area of 34 m{sup 2}. The greenhouse, located in Riyadh, Saudi Arabia, was planted with tomatoes with a leaf area index (LAI) of 3.0 and was cooled by a wet pad and fan system. Results of the presented relations were accurate and more realistic comparing to results of other relations reported in the literatures. Absorption of solar radiation by water vapor in the greenhouse was negligible. The presented relations can estimate the absorbed and lost energy terms for a greenhouse precisely with a max possible error of +1.8% on each term if the LAI was less than 1.5. The error is significantly decreased to less than +0.7% if the LAI in the greenhouse is increased to 5. (author)
A Validation Study of the General Amber Force Field Applied to Energetic Molecular Crystals
Bergh, Magnus; Caleman, Carl
2016-01-01
Molecula dynamics is a well-established tool to computationally study molecules. However, to reach predictive capability at the level required for applied research and design, extensive validation of the available force fields is pertinent. Here we present a study of density, isothermal compressibility and coefficients of thermal expansion of four energetic materials (FOX-7, RDX, CL-20 and HMX) based on molecular dynamics simulations with the General Amber Force Field (GAFF), and compare the results to experimental measurements from the literature. Furthermore, we quantify the accuracy of the calculated properties through hydrocode simulation of a typical impact scenario. We find that molecular dynamics simulations with generic and computationally efficient force fields may be used to understand and estimate important physical properties of nitramine-like energetic materials.
Psychiatric screening in the emergency department: validation of the General Health Questionnaire.
Gold, I; Haughey, L; Baraff, L J
1985-09-01
Both a 28-item psychiatric scale, the Goldberg General Health Questionnaire (GHQ), and the National Institute of Mental Health (NIMH) Diagnostic Interview Schedule (DIS) were administered to 25 emergency department patients to determine the validity of the GHQ as a screening instrument for psychopathology in the emergency department setting. There was a significant association (P = 0.0343) between GHQ scores and DIS assessment. The sensitivity of the GHQ in this series was 55.6% and the specificity was 87.5% when compared with the DIS. This suggests that the GHQ may prove to be a valuable screening tool for patients with somatic complaints to detect unsuspected psychiatric illness in the emergency department.
Noise Resistant Generalized Parametric Validity Index of Clustering for Gene Expression Data.
Fa, Rui; Nandi, Asoke K
2014-01-01
Validity indices have been investigated for decades. However, since there is no study of noise-resistance performance of these indices in the literature, there is no guideline for determining the best clustering in noisy data sets, especially microarray data sets. In this paper, we propose a generalized parametric validity (GPV) index which employs two tunable parameters α and β to control the proportions of objects being considered to calculate the dissimilarities. The greatest advantage of the proposed GPV index is its noise-resistance ability, which results from the flexibility of tuning the parameters. Several rules are set to guide the selection of parameter values. To illustrate the noise-resistance performance of the proposed index, we evaluate the GPV index for assessing five clustering algorithms in two gene expression data simulation models with different noise levels and compare the ability of determining the number of clusters with eight existing indices. We also test the GPV in three groups of real gene expression data sets. The experimental results suggest that the proposed GPV index has superior noise-resistance ability and provides fairly accurate judgements.
Validation of the Rasch-based Depression Screening in a large scale German general population sample
Directory of Open Access Journals (Sweden)
Norra Christine
2010-09-01
Full Text Available Abstract Background The study aimed at presenting normative data for both parallel forms of the "Rasch-based Depression Screening (DESC", to examine its Rasch model conformity and convergent and divergent validity based on a representative sample of the German general population. Methods The sample was selected with the assistance of a demographic consulting company applying a face to face interview (N = 2509; mean age = 49.4, SD = 18.2; 55.8% women. Adherence to Rasch model assumptions was determined with analysis of Rasch model fit (infit and outfit, unidimensionality, local independence (principal component factor analysis of the residuals, PCFAR and differential item functioning (DIF with regard to participants' age and gender. Norm values were calculated. Convergent and divergent validity was determined through intercorrelations with the depression and anxiety subscales of the Hospital Anxiety and Depression Scale (HADS-D and HADS-A. Results Fit statistics were below critical values (rDESC-I = .61 and rDESC-II = .60, whereas correlations with HADS-A were rDESC-I = .62 and rDESC-II = .60. Conclusions This study provided further support for the psychometric quality of the DESC. Both forms of the DESC adhered to Rasch model assumptions and showed intercorrelations with HADS subscales that are in line with the literature. The presented normative data offer important advancements for the interpretation of the questionnaire scores and enhance its usefulness for clinical and research applications.
Boyer, Laurent; Richieri, Raphaëlle; Guedj, Eric; Faget-Agius, Catherine; Loundou, Anderson; Llorca, Pierre-Michel; Auquier, Pascal; Lançon, Christophe
2013-10-01
The aim of this study was to develop a functional remission threshold for the Functional Remission Of General Schizophrenia (FROGS) scale, and test its validity regarding clinical and quality of life outcomes. Cross-sectional study. Schizophrenia according to DSM-IV-TR criteria. Functioning was assessed using the FROGS and the Global Assessment of Functioning (GAF) scales; psychotic symptoms using the Positive and Negative Syndrome Scale; memory, attention, and executive functions were assessed using the California Verbal Learning Test, the D2 attention task, the Stroop color-word test, the verbal fluency test, the Trail Making Test A and B and the Wechsler Adult Intelligence Scale; and quality of life using the schizophrenia quality of life (S-QoL 18) scale. A logistic regression analysis including the different dimensions of the FROGS was used to create a composite score to classify patients into remitted and non-remitted according a gold standard (cut-off: GAF>= 61). Receiver operating characteristics analyses were then performed to determine the area under the curve (AUC). Of 137 patients enrolled, 26 were functionally remitted and 111 were not remitted according to GAF score. The AUC for the combination of the FROGS's dimensions to detect functional remission was 0.903 (p<0.001). Sensitivity and specificity for the combination of the FROGS dimensions using the Youden index were 88.5 [69.8; 97.6] and 81.1 [72.5; 87.9], respectively. Validity of this combination was satisfactory. Patients in functional remission had a lower severity of the disease, especially for PANSS negative (p<0.001) and general psychopathology (p<0.001) symptoms. Only two cognitive functions (i.e. fluency and episodic memory) were improved in remitted patients. Higher quality of life levels were globally associated with better functioning. These findings provide for first accurate FROGS thresholds to detect functional remission in schizophrenia. Copyright © 2013 Elsevier Inc. All rights
Directory of Open Access Journals (Sweden)
Riëtta Oberink
2017-11-01
Full Text Available Abstract Background The Motivational Interviewing target Scheme (MITS is an instrument to assess competency in Motivational Interviewing (MI and can be used to assess MI in long and brief consultations. In this qualitative study we examined two sources of the Unified Model of Validity, the current standard of assessment validation, in the context of General Practice. We collected evidence concerning response process validity and content validity of the MITS in general practice. Furthermore, we investigated its feasibility. Methods Assessing consultations of General Practitioners and GP-trainees (GPs, the assessors systematically noted down their considerations concerning the scoring process and the content of the MITS in a semi-structured questionnaire. Sampling of the GPs was based on maximum variation and data saturation was used as a stopping criterion. An inductive approach was used to analyse the data. In response to scoring problems the score options were adjusted and all consultations were assessed using the original and the adjusted score options. Results Twenty seven assessments were needed to reach data saturation. In most consultations, the health behaviour was not the reason for encounter but was discussed on top of discussing physical problems. The topic that was most discussed in the consultations was smoking cigarettes. The adjusted score options increased the response process validity; they were more in agreement with theoretical constructs and the observed quality of MI in the consultations. Concerning content validity, we found that the MITS represents the broad spectrum and the current understanding of MI. Furthermore, the MITS proved to be feasible to assess MI in brief consultations in general practice. Conclusions Based on the collected evidence the MITS seems a promising instrument to measure MI interviewing in brief consultations. The evidence gathered in this study lays the foundation for research into other aspects of
Criterion-related validity of challenging behaviour scales: a review of evidence in the literature.
Turton, Raistrick W
2015-03-01
Behaviour that challenges has negative impacts on physical and emotional well-being and quality of life. Challenging behaviour scales are used to identify needs and evaluate interventions and must be valid measures. Criterion-related validity is important, and the best quality assessment uses direct measures of behaviour as criteria. Previous reviews of scales affirm their validity but present little supporting evidence. The current review examines the evidence presented in studies of validity. Searches of MEDLINE and PsycINFO to identify scales that focus on challenging behaviour and find publications that assess their criterion-related validity. Searches identified twelve scales and 21 publications that assess validity. One assessment used direct measures of behaviour, and the remainder used indirect measures that themselves have limited evidence of validity, including membership of diagnostic or service groups and other scales. Little firm evidence of validity was found, but what was found is encouraging. © 2014 John Wiley & Sons Ltd.
Stability and relative validity of the Neuromuscular Disease Impact Profile (NMDIP).
Bos, Isaäc; Kuks, Jan B M; Almansa, Josué; Kremer, Hubertus P H; Wynia, Klaske
2017-05-11
The aim of this study was to examine the stability and relative validity (RV) of the Neuromuscular Disease Impact Profile (NMDIP) using criterion-related groups. In a previous study the NMDIP-scales showed good internal consistency, convergent and discriminant validity. Known-groups analysis showed that the NMDIP discriminates between categories of extent of limitations. A cross-sectional postal survey study was performed on patients diagnosed with a NMD and registered at the Department of Neurology, University Medical Center Groningen, the Netherlands. Participants were asked to complete the preliminary NMDIP, the Medical Outcome study Short Form Questionnaire (SF-36), the World Health Organization Quality Of Life-abbreviation version (WHOQOL-bref), and two generic domain specific measures: the Groningen Activity Restriction Scale (GARS) and the Impact on Participation and Autonomy Questionnaire (IPAQ). The variables 'Extent of Limitations' and 'Quality of Life' were used to create criterion-related groups. Stability over time was tested using the Wilcoxon Signed Rank Test for paired samples and the intraclass correlation coefficients for repeated measures. RV was examined by comparing the ability of NMDIP with generic multidimensional health impact measures, and domain specific measures in discriminating between criterion-related subgroups using the Kruskal-Wallis H-test. Response rate was 70% (n = 702). The NMDIP-scales showed sufficient stability over time, and satisfactory or strong RV. In general, the NMDIP scales performed as well as or better than the concurrent measurement instruments. The NMDIP proved to be a valid and reliable disease-targeted measure with a broad scope on physical, psychological and social functioning.
Einstein's general theory of relativity with modern applications in cosmology
Grøn, Øyvind
2007-01-01
Many of us have experienced the same; fallen and broken something. Yet supposedly, gravity is the weakest of the fundamental forces; it is claimed to be 10-15 times weaker than electromagnetism. Still, every one of us has more or less had a personal relationship with gravity. Einstein’s General Theory of Relativity: With Modern Applications in Cosmology by Oyvind Gron and Sigbjorn Hervik is about gravity and the concept of gravity as Albert Einstein saw it- curved spaces, four-dimensional manifolds and geodesics. The book starts with the 1st principals of relativity and an introduction to Einstein’s field equations. Next up are the three classical tests of the relativity theory and an introduction to black holes. The book contains several topics not found in other textbooks, such as Kaluza-Klein theory, anisotropic models of the universe, and new developments involving brane cosmology. Gron and Hervik have included a part in the book called "Advanced Topics." These topics range from the very edge of resea...
On the relation between barycentric and "good" geocentric coordinates in general relativity.
Soffel, M.; Xu, Chongming
The problem of "good" geocentric coordinates in the framework of general relativity is discussed. The recent work by Brumberg and Kopejkin suggests that the use of harmonic, non-rotating and comoving coordinates has several advantages over the use of generalized Fermi normal coordinates. The technique of matching the global (barycentric) with the local (geocentric) metric then not only determines the geocentric metric and the coordinate transformation between global and local coordinates but also the equations of motion.
Outer boundary as arrested history in general relativity
Lau, S
2002-01-01
We present explicit outer boundary conditions for the canonical variables of general relativity. The conditions are associated with the causal evolution of a finite Cauchy domain, a so-called quasilocal boost, and they suggest a consistent scheme for modelling such an evolution numerically. The scheme involves a continuous boost in the spacetime orthogonal complement 'orthogonal' T sub p (B) of the tangent space T sub p (B) belonging to each point p on the system boundary B. We show how the boost rate may be computed numerically via equations similar to those appearing in canonical investigations of black-hole thermodynamics (although here holding at an outer two-surface rather than the bifurcate two-surface of a Killing horizon). We demonstrate the numerical scheme on a model example, the quasilocal boost of a spherical three-ball in Minkowski spacetime. Developing our general formalism with recent hyperbolic formulations of the Einstein equations in mind, we use Anderson and York's 'Einstein-Christoffel' hy...
Motivations for anti-gravity in general relativity
Energy Technology Data Exchange (ETDEWEB)
Chardin, G. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee
1996-05-01
Arguments are presented showing that it is natural to interpret the negative mass part of the Kerr solution as representing the geometry experienced by antimatter. The C, P and T discrete transformations are considered for this geometry. The C and T properties of the proposed identification are found to be in agreement with the usual representation of antimatter. In addition, a property of perfect stigmatism through Kerr wormholes which allows general relativity to mimic anti-gravity is conjectured. Kerr wormholes would then act as `super-mirrors` reversing the C, P and T images of an object seen through it. This interpretation is subjected to several experimental tests and able to provide an explanation, without any free parameter, of the `CP`-violation observed in the neutral kaon system. (K.A.). 37 refs.
Collapse of magnetized hypermassive neutron stars in general relativity.
Duez, Matthew D; Liu, Yuk Tung; Shapiro, Stuart L; Shibata, Masaru; Stephens, Branson C
2006-01-27
Hypermassive neutron stars (HMNSs)--equilibrium configurations supported against collapse by rapid differential rotation--are possible transient remnants of binary neutron-star mergers. Using newly developed codes for magnetohydrodynamic simulations in dynamical spacetimes, we are able to track the evolution of a magnetized HMNS in full general relativity for the first time. We find that secular angular momentum transport due to magnetic braking and the magnetorotational instability results in the collapse of an HMNS to a rotating black hole, accompanied by a gravitational wave burst. The nascent black hole is surrounded by a hot, massive torus undergoing quasistationary accretion and a collimated magnetic field. This scenario suggests that HMNS collapse is a possible candidate for the central engine of short gamma-ray bursts.
Commutative deformations of general relativity: nonlocality, causality, and dark matter
Energy Technology Data Exchange (ETDEWEB)
De Vegvar, P.G.N. [SWK Research, Bellingham, WA (United States)
2017-01-15
Hopf algebra methods are applied to study Drinfeld twists of (3+1)-diffeomorphisms and deformed general relativity on commutative manifolds. A classical nonlocality length scale is produced above which microcausality emerges. Matter fields are utilized to generate self-consistent Abelian Drinfeld twists in a background independent manner and their continuous and discrete symmetries are examined. There is negligible experimental effect on the standard model of particles. While baryonic twist producing matter would begin to behave acausally for rest masses above ∝1-10 TeV, other possibilities are viable dark matter candidates or a right-handed neutrino. First order deformed Maxwell equations are derived and yield immeasurably small cosmological dispersion and produce a propagation horizon only for photons at or above Planck energies. This model incorporates dark matter without any appeal to extra dimensions, supersymmetry, strings, grand unified theories, mirror worlds, or modifications of Newtonian dynamics. (orig.)
Cosmology in time asymmetric extensions of general relativity
Leon, Genly
2015-01-01
We investigate the cosmological behavior in a universe governed by time asymmetric extensions of general relativity, which is a novel modified gravity based on the addition of new, time-asymmetric, terms on the Hamiltonian framework, in a way that the algebra of constraints and local physics remain unchanged. Nevertheless, at cosmological scales these new terms can have significant effects that can alter the universe evolution, both at early and late times, and the freedom in the choice of the involved modification function makes the scenario able to produce a huge class of cosmological behaviors. For basic ansatzes of modification, we perform a detailed dynamical analysis, extracting the stable late time solutions. Amongst others, we find that the universe can result in dark-energy dominated, accelerating solutions, even in the absence of an explicit cosmological constant, in which the dark energy can be quintessence-like, phantom-like, or behave as an effective cosmological constant. Moreover, it can result...
CPT symmetry and antimatter gravity in general relativity
Villata, M
2011-01-01
The gravitational behavior of antimatter is still unknown. While we may be confident that antimatter is self-attractive, the interaction between matter and antimatter might be either attractive or repulsive. We investigate this issue on theoretical grounds. Starting from the CPT invariance of physical laws, we transform matter into antimatter in the equations of both electrodynamics and gravitation. In the former case, the result is the well-known change of sign of the electric charge. In the latter, we find that the gravitational interaction between matter and antimatter is a mutual repulsion, i.e. antigravity appears as a prediction of general relativity when CPT is applied. This result supports cosmological models attempting to explain the Universe accelerated expansion in terms of a matter-antimatter repulsive interaction.
Astrometric tests of General Relativity in the Solar system
Gai, M.; Vecchiato, A.; Riva, A.; Lattanzi, M. G.; Sozzetti, A.; Crosta, M. T.; Busonero, D.
2014-03-01
Micro-arcsec astronomy is able to verify the predictions of theoretical models of gravitation at a level adequate to constraint relevant parameters and select among different formulations. In particular, this concerns the weak field limit applicable to the Sun neighborhood, where competing models can be expressed in a common framework as the Parametrised Post-Newtonian and Parametrised Post-Post-Newtonian formulations. The mission Gaia is going to provide an unprecedented determination of the γ PPN parameter at the 10-6 level. Other recently proposed concepts, as GAME, may improve the precision on γ by one or two orders of magnitude and provide constraints on other crucial phenomenological aspects. We review the key concepts of astrometric tests of General Relativity and discuss a possible development scenario.
CPT symmetry and antimatter gravity in general relativity
Villata, M.
2011-04-01
The gravitational behavior of antimatter is still unknown. While we may be confident that antimatter is self-attractive, the interaction between matter and antimatter might be either attractive or repulsive. We investigate this issue on theoretical grounds. Starting from the CPT invariance of physical laws, we transform matter into antimatter in the equations of both electrodynamics and gravitation. In the former case, the result is the well-known change of sign of the electric charge. In the latter, we find that the gravitational interaction between matter and antimatter is a mutual repulsion, i.e. antigravity appears as a prediction of general relativity when CPT is applied. This result supports cosmological models attempting to explain the Universe accelerated expansion in terms of a matter-antimatter repulsive interaction.
Gravitating vortons as ring solitons in general relativity
Kunz, Jutta; Subagyo, Bintoro
2013-01-01
Vortons can be viewed as (flat space-) field theory analogs of black rings in general relativity. They are made from loops of vortices, being sustained against collapse by the centrifugal force. In this work we discuss such configurations in the global version of Witten's U(1)xU(1) theory. We first consider solutions in a flat spacetime background and show their non-uniqueness. The inclusion of gravity leads to new features. In particular, an ergoregion can occur. Also, similar to boson stars, we show that the vortons exist only in a limited frequency range. The coupling to gravity gives rise to a spiral-like frequency dependence of the mass and charge. New solutions of the model describing 'semitopological vortons' and 'di-vortons' are also discussed.
General Relativity and Cosmology: Unsolved Questions and Future Directions
Directory of Open Access Journals (Sweden)
Ivan Debono
2016-09-01
Full Text Available For the last 100 years, General Relativity (GR has taken over the gravitational theory mantle held by Newtonian Gravity for the previous 200 years. This article reviews the status of GR in terms of its self-consistency, completeness, and the evidence provided by observations, which have allowed GR to remain the champion of gravitational theories against several other classes of competing theories. We pay particular attention to the role of GR and gravity in cosmology, one of the areas in which one gravity dominates and new phenomena and effects challenge the orthodoxy. We also review other areas where there are likely conflicts pointing to the need to replace or revise GR to represent correctly observations and consistent theoretical framework. Observations have long been key both to the theoretical liveliness and viability of GR. We conclude with a discussion of the likely developments over the next 100 years.
Probing strong-field general relativity near black holes
CERN. Geneva; Alvarez-Gaumé, Luís
2005-01-01
Nature has sprinkled black holes of various sizes throughout the universe, from stellar mass black holes in X-ray sources to supermassive black holes of billions of solar masses in quasars. Astronomers today are probing the spacetime near black holes using X-rays, and gravitational waves will open a different view in the near future. These tools give us an unprecedented opportunity to test ultra-strong-field general relativity, including the fundamental theorem of the uniqueness of the Kerr metric and Roger Penrose's cosmic censorship conjecture. Already, fascinating studies of spectral lines are showing the extreme gravitational lensing effects near black holes and allowing crude measurements of black hole spin. When the ESA-NASA gravitational wave detector LISA begins its observations in about 10 years, it will make measurements of dynamical spacetimes near black holes with an accuracy greater even than that which theoreticians can reach with their computations today. Most importantly, when gravitational wa...
Hydrodynamics in full general relativity with conservative AMR
East, William E; Stephens, Branson C
2011-01-01
There is great interest in numerical relativity simulations involving matter due to the likelihood that binary compact objects (BCOs) involving neutron stars will be detected by gravitational wave observatories in the coming years, as well as to the possibility that BCO mergers could explain short-duration gamma-ray bursts. We present a code designed for simulations of hydrodynamics coupled to the Einstein field equations targeted toward such applications. This code has recently been used to study eccentric mergers of black hole-neutron star binaries. We evolve the fluid conservatively using high-resolution shock capturing methods, while the field equations are solved in the generalized harmonic formulation with finite differences. In order to resolve the various scales that may arise, we use adaptive mesh refinement (AMR) with grid hierarchies based on truncation error estimates. A noteworthy feature of this code is the implementation of the flux correction algorithm of Berger and Colella to ensure that cons...
Cross-cultural adaptation and validation to Brazil of the Obesity-related Problems Scale.
Brasil, Andreia Mara Brolezzi; Brasil, Fábio; Maurício, Angélica Aparecida; Vilela, Regina Maria
2017-01-01
To validate a reliable version of the Obesity-related Problems Scale in Portuguese to use it in Brazil. The Obesity-related Problems Scale was translated and transculturally adapted. Later it was simultaneously self-applied with a 12-item version of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), to 50 obese patients and 50 non-obese individuals, and applied again to half of them after 14 days. The Obesity-related Problems scale was able to differentiate obese from non-obese individuals with higher accuracy than WHODAS 2.0, correlating with this scale and with body mass index. The factor analysis determined a two-dimensional structure, which was confirmed with χ2/df=1.81, SRMR=0.05, and CFI=0.97. The general a coefficient was 0.90 and the inter-item intra-class correlation, in the reapplication, ranged from 0.75 to 0.87. The scale proved to be valid and reliable for use in the Brazilian population, without the need to exclude items.
Generalized Convex Functions on Fractal Sets and Two Related Inequalities
Directory of Open Access Journals (Sweden)
Huixia Mo
2014-01-01
Full Text Available We introduce the generalized convex function on fractal sets Rα (0<α≤1 of real line numbers and study the properties of the generalized convex function. Based on these properties, we establish the generalized Jensen’s inequality and generalized Hermite-Hadamard's inequality. Furthermore, some applications are given.
Slieker-ten Hove, Marijke; Pool-Goudzwaard, Annelies; Eijkemans, René; Steegers-Theunissen, Régine; BURGER, Curt; Vierhout, M.E.
2009-01-01
markdownabstractINTRODUCTION AND HYPOTHESIS: The objective of this study is to describe pelvic floor muscle function (PFMF) in relation to age and parity in a general female population and to test whether strength/endurance measurements represent all functions of the pelvic floor musculature. METHODS: A cross-sectional study was performed on 95% of the women aged 45-85 years from a small Dutch town. Validated questionnaires were used to obtain general information, and vaginal examination to t...
Directory of Open Access Journals (Sweden)
Wendy Wing Tak Lam
Full Text Available Illness perceptions are linked to individual help-seeking and preventive behaviors. Previous illness perception studies have identified five dimensions of illness-related experience and behaviour. The Revised Illness Perception Questionnaire (IPQ-R for genetic predisposition (IPQ-R-GP was developed to measure illness perceptions in those genetically-predisposed to blood disease. We adapted the IPQ-R-GP to measure perceptions of generalized cancer predisposition. This paper describes the development and validation of the Cancer Predisposition Perception Scale (CPPS.The draft CPPS scale was first administered to 167 well Hepatitis B carriers and 123 other healthy individuals and the factor structure was examined using Exploratory Factor Analysis. Then the factor structure was confirmed in a second sample comprising 148 healthy controls, 150 smokers and 152 passive smokers using Confirmatory Factor Analysis (CFA.Six-factors comprising 26 items provided optimal fit by eigen and scree-plot methods, accounting for 58.9% of the total variance. CFA indicated good fit of the six-factor model after further excluding three items. The six factors, Emotional representation (5 items, Illness coherence (4 items, Treatment control (3 items, Consequences (5 items, Internal locus of control (2 items and External locus of control (4 items demonstrated adequate-to-good subscale internal consistency (Cronbach's α = 0.63-0.90. Divergent validity was suggested by low correlations with optimism, self-efficacy, and scales for measuring physical and psychological health symptoms.The CPPS appears to be a valid measure of perceived predisposition to generic cancer risks and can be used to examine cancer-risk-related cognitions in individuals at higher and lower cancer risk.
Origins and development of the Cauchy problem in general relativity
Ringström, Hans
2015-06-01
The seminal work of Yvonne Choquet-Bruhat published in 1952 demonstrates that it is possible to formulate Einstein's equations as an initial value problem. The purpose of this article is to describe the background to and impact of this achievement, as well as the result itself. In some respects, the idea of viewing the field equations of general relativity as a system of evolution equations goes back to Einstein himself; in an argument justifying that gravitational waves propagate at the speed of light, Einstein used a special choice of coordinates to derive a system of wave equations for the linear perturbations on a Minkowski background. Over the following decades, Hilbert, de Donder, Lanczos, Darmois and many others worked to put Einstein's ideas on a more solid footing. In fact, the issue of local uniqueness (giving a rigorous justification for the statement that the speed of propagation of the gravitational field is bounded by that of light) was already settled in the 1930s by the work of Stellmacher. However, the first person to demonstrate both local existence and uniqueness in a setting in which the notion of finite speed of propagation makes sense was Yvonne Choquet-Bruhat. In this sense, her work lays the foundation for the formulation of Einstein's equations as an initial value problem. Following a description of the results of Choquet-Bruhat, we discuss the development of three research topics that have their origin in her work. The first one is local existence. One reason for addressing it is that it is at the heart of the original paper. Moreover, it is still an active and important research field, connected to the problem of characterizing the asymptotic behaviour of solutions that blow up in finite time. As a second topic, we turn to the questions of global uniqueness and strong cosmic censorship. These questions are of fundamental importance to anyone interested in justifying that the Cauchy problem makes sense globally. They are also closely
Relativity, GPS, and the Validity of Common View Synchronization
Michelsen, Eric L
2012-01-01
We show here that Common View Synchronization is valid to synchronize distant clocks. We describe the relativistic physics, noting that a prerequisite for synchronization is the existence of a space-time with a stationary metric. The analysis shows that there are no Special Relativistic effects that need be included in the synchronization method, beyond those in a standard GPS clock. In particular, synchronizing a ground clock to the GPS satellite does not make that clock keep time in the reference frame of the satellite. Symmetries are very helpful in analyzing the behavior. We briefly describe some practical considerations in synchronizing distant earth clocks, such as antenna cabling and variations in receiver electronics, and how Common View Synchronization accommodates them.
The General Environment Fit Scale: A Factor Analysis and Test of Convergent Construct Validity
Beasley, Christopher; Jason, Leonard; Miller, Steven
2014-01-01
Person-environment fit (P-E fit) was initially espoused as an important construct in the field of community psychology; however, most of the theoretical and empirical development of the construct has been conducted by industrial/organizational (I/O) psychologists. In the current study, the GEFS—a P-E fit measure was developed from I/O and business management perspectives on fit—was administered to 246 attendees of an annual convention for residents and alumni of Oxford House (OH), a network of over 1400 mutual-help recovery homes. The authors conducted confirmatory factor and convergent construct validity analyses on the GEFS. The results suggested that the theoretical factor structure of the measure adequately fit the data, suggesting that the GEFS is a valid measure of P-E fit. OH resident fit with their recovery home was related to satisfaction, but not expected tenure. Exploratory analyses revealed that the sufficient supply of resident needs by the recovery home and similarity between residents and their housemates predicted satisfaction with the recovery home, but only similarity with housemates predicted how long residents intended to stay in the OHs. PMID:22071911
Stability and relative validity of the Neuromuscular Disease Impact Profile (NMDIP)
Bos, Isaac; Kuks, Jan B. M.; Almansa, Josue; Kremer, Hubertus P. H.; Wynia, Klaske
2017-01-01
Background: The aim of this study was to examine the stability and relative validity (RV) of the Neuromuscular Disease Impact Profile (NMDIP) using criterion-related groups. In a previous study the NMDIP-scales showed good internal consistency, convergent and discriminant validity. Known-groups
Validity of the einstein relation in disordered organic semiconductors
Wetzelaer, G.A.H.; Koster, L.J.A.; Blom, P.W.M.
2011-01-01
It is controversial whether energetic disorder in semiconductors is already sufficient to violate the classical Einstein relation, even in the case of thermal equilibrium. We demonstrate that the Einstein relation is violated only under nonequilibrium conditions due to deeply trapped carriers, as in
Validity of the Einstein Relation in Disordered Organic Semiconductors
Wetzelaer, G. A. H.; Koster, L. J. A.; Blom, P. W. M.
2011-01-01
It is controversial whether energetic disorder in semiconductors is already sufficient to violate the classical Einstein relation, even in the case of thermal equilibrium. We demonstrate that the Einstein relation is violated only under nonequilibrium conditions due to deeply trapped carriers, as in
Directory of Open Access Journals (Sweden)
Lee Lok-chun
2010-11-01
Full Text Available Abstract Background The effects of the built environment on walking in seniors have not been studied in an Asian context. To examine these effects, valid and reliable measures are needed. The aim of this study was to develop and validate a questionnaire of perceived neighborhood characteristics related to walking appropriate for Chinese seniors (Neighborhood Environment Walkability Scale for Chinese Seniors, NEWS-CS. It was based on the Neighborhood Environment Walkability Scale - Abbreviated (NEWS-A, a validated measure of perceived built environment developed in the USA for adults. A secondary study aim was to establish the generalizability of the NEWS-A to an Asian high-density urban context and a different age group. Methods A multidisciplinary panel of experts adapted the original NEWS-A to reflect the built environment of Hong Kong and needs of seniors. The translated instrument was pre-tested on a sample of 50 Chinese-speaking senior residents (65+ years. The final version of the NEWS-CS was interviewer-administered to 484 seniors residing in four selected Hong Kong districts varying in walkability and socio-economic status. Ninety-two participants completed the questionnaire on two separate occasions, 2-3 weeks apart. Test-rest reliability indices were estimated for each item and subscale of the NEWS-CS. Confirmatory factor analysis was used to develop the measurement model of the NEWS-CS and cross-validate that of the NEWS-A. Results The final version of the NEWS-CS consisted of 14 subscales and four single items (76 items. Test-retest reliability was moderate to good (ICC > 50 or % agreement > 60 except for four items measuring distance to destinations. The originally-proposed measurement models of the NEWS-A and NEWS-CS required 2-3 theoretically-justifiable modifications to fit the data well. Conclusions The NEWS-CS possesses sufficient levels of reliability and factorial validity to be used for measuring perceived neighborhood
Hirsch Index Value and Variability Related to General Surgery in a UK Deanery.
Abdelrahman, Tarig; Brown, Josephine; Wheat, Jenny; Thomas, Charlotte; Lewis, Wyn
2016-01-01
The Hirsch Index (h-index) is often used to assess research impact, and on average a social science senior lecturer will have an h-index of 2.29, yet its validity within the context of UK General Surgery (GS) is unknown. The aim of this study was to calculate the h-indices of a cohort of GS consultants in a UK Deanery to assess its relative validity. Individual h-indices and total publication (TP) counts were obtained for GS consultants via the Scopus and Web of Science (WoS) Internet search engines. Assessment of construct validity and reliability of these 2 measures of the h-index was undertaken. All hospitals in a single UK National Health Service Deanery were included (14 general hospitals). All 136 GS consultants from the Deanery were included. Median h-index (Scopus) was 5 (0-52) and TP 15 (0-369), and strong correlation was found between h-index and TP (ρ = 0.932, p Scopus and WoS h-index also significant (intraclass correlation coefficient = 0.973 [95% CI: 0.962-0.981], p Scopus 12 vs 7 vs 4 [p 2.29 in 57.4% of consultants. No subspecialty differences were apparent in median h-indices (p = 0.792) and TP (p = 0.903). h-Index is a valid GS research productivity metric with over half of consultants performing at levels equivalent to social science Senior Lecturers. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
Testing general relativity with present and future astrophysical observations
Berti, Emanuele; Barausse, Enrico; Cardoso, Vitor; Gualtieri, Leonardo; Pani, Paolo; Sperhake, Ulrich; Stein, Leo C.; Wex, Norbert; Yagi, Kent; Baker, Tessa; Burgess, C. P.; Coelho, Flávio S.; Doneva, Daniela; De Felice, Antonio; Ferreira, Pedro G.; Freire, Paulo C. C.; Healy, James; Herdeiro, Carlos; Horbatsch, Michael; Kleihaus, Burkhard; Klein, Antoine; Kokkotas, Kostas; Kunz, Jutta; Laguna, Pablo; Lang, Ryan N.; Li, Tjonnie G. F.; Littenberg, Tyson; Matas, Andrew; Mirshekari, Saeed; Okawa, Hirotada; Radu, Eugen; O'Shaughnessy, Richard; Sathyaprakash, Bangalore S.; Van Den Broeck, Chris; Winther, Hans A.; Witek, Helvi; Emad Aghili, Mir; Alsing, Justin; Bolen, Brett; Bombelli, Luca; Caudill, Sarah; Chen, Liang; Degollado, Juan Carlos; Fujita, Ryuichi; Gao, Caixia; Gerosa, Davide; Kamali, Saeed; Silva, Hector O.; Rosa, João G.; Sadeghian, Laleh; Sampaio, Marco; Sotani, Hajime; Zilhao, Miguel
2015-12-01
One century after its formulation, Einstein's general relativity (GR) has made remarkable predictions and turned out to be compatible with all experimental tests. Most of these tests probe the theory in the weak-field regime, and there are theoretical and experimental reasons to believe that GR should be modified when gravitational fields are strong and spacetime curvature is large. The best astrophysical laboratories to probe strong-field gravity are black holes and neutron stars, whether isolated or in binary systems. We review the motivations to consider extensions of GR. We present a (necessarily incomplete) catalog of modified theories of gravity for which strong-field predictions have been computed and contrasted to Einstein's theory, and we summarize our current understanding of the structure and dynamics of compact objects in these theories. We discuss current bounds on modified gravity from binary pulsar and cosmological observations, and we highlight the potential of future gravitational wave measurements to inform us on the behavior of gravity in the strong-field regime.
Preferred Spatial Directions in the Universe: a General Relativity Approach
Directory of Open Access Journals (Sweden)
Borissova L.
2006-10-01
Full Text Available Herein is constructed, using General Relativity, the space metric along the Earth’s trajectory in the Galaxy, where the Earth traces outs a complicated spiral in its orbital motion around the Sun and its concomitant motion with the solar system around the centre of the Galaxy. It is deduced herein that this space is inhomogeneous and anisotropic. The observable properties of the space, characterizing its gravitation, rotation, deformation, and curvature, are obtained. The theory predicts that the observable velocity of light is anisotropic, due to the anisotropy and inhomogeneity of space caused by the presence of gravitation and the space rotation, despite the world-invariance of the velocity of light remaining unchanged. It is calculated that two pairs of synchronised clocks should record a different speed of light for light beams travelling towards the Sun and orthogonal to this direction, of about 4×10−4 c (i. e. 120 km/sec, 0.04% of the measured velocity of light c. This effect should have oscillations with a 12-hour period (due to the daily rotation of the Earth and 6 month period (due to the motion of the Earth around the Sun. The best equipment for detecting the effect is that being used by R. T. Cahill (Flinders University, Australia in his current experiments measuring the velocity of light in an RF coaxial-cable equipped with a pair of high precision synchronized Rb atomic clocks.
Classical tests of General Relativity in thick branes
Dahia, F.; de Albuquerque Silva, Alex
2015-02-01
Classical tests of General Relativity in braneworld scenarios have been investigated recently with the purpose of posing observational constraints on the parameters of some models of infinitely thin brane. Here we consider the motion of test particles in a thick brane scenario that corresponds to a regularized version of the Garriga-Tanaka solution, which describes a black hole solution in RSII model, in the weak field regime. By adapting a mechanism previously formulated in order to describe the confinement of massive tests particles in a domain wall (which simulates classically the trapping of the Dirac field in a domain wall), we study the influence of the brane thickness on the four-dimensional (4D) path of massless particles. Although the geometry is not warped and, therefore, the bound motion in the transverse direction is not decoupled from the movement in the 4D-world, we can find an explicit solution for the light deflection and the time delay, if the motion in the fifth direction is a high frequency oscillation. We verify that, owing to the transverse motion, the light deflection and the time delay depend on the energy of the light rays. This feature may lead to the phenomenon of gravitational rainbow. We also consider the problem from a semi-classical perspective, investigating the effects of the brane thickness on the motion of the zero-mode in the 4D-world.
Hydrodynamics in full general relativity with conservative adaptive mesh refinement
East, William E.; Pretorius, Frans; Stephens, Branson C.
2012-06-01
There is great interest in numerical relativity simulations involving matter due to the likelihood that binary compact objects involving neutron stars will be detected by gravitational wave observatories in the coming years, as well as to the possibility that binary compact object mergers could explain short-duration gamma-ray bursts. We present a code designed for simulations of hydrodynamics coupled to the Einstein field equations targeted toward such applications. This code has recently been used to study eccentric mergers of black hole-neutron star binaries. We evolve the fluid conservatively using high-resolution shock-capturing methods, while the field equations are solved in the generalized-harmonic formulation with finite differences. In order to resolve the various scales that may arise, we use adaptive mesh refinement (AMR) with grid hierarchies based on truncation error estimates. A noteworthy feature of this code is the implementation of the flux correction algorithm of Berger and Colella to ensure that the conservative nature of fluid advection is respected across AMR boundaries. We present various tests to compare the performance of different limiters and flux calculation methods, as well as to demonstrate the utility of AMR flux corrections.
Relative validation of a food frequency questionnaire for national health and nutrition monitoring
Directory of Open Access Journals (Sweden)
Haftenberger Marjolein
2010-09-01
Full Text Available Abstract Background Validation of a food frequency questionnaire (FFQ is important as incorrect information may lead to biased associations. Therefore the relative validity of an FFQ developed for use in the German Health Examination Survey for Adults 2008-2011 (DEGS was examined. Methods Cross-sectional comparisons of food consumption data from the FFQ and from two 24-hour recalls were made in a sample of 161 participants (aged 18 to 80 years of an ongoing nationwide survey, the German National Nutrition Monitoring (NEMONIT. The data collection took place from November 2008 to April 2009. Results Spearman rank correlations between the FFQ and the 24-hour dietary recalls ranged from 0.15 for pizza to 0.80 for tea, with two third of the correlation coefficients exceeding 0.30. All correlation coefficients were statistically significant except those for pizza and cooked vegetables. The proportion of participants classified into the same or adjacent quartile of intake assessed by both methods varied between 68% for cooked vegetables and 94% for coffee. There were no statistically significant differences in food consumption estimates between both methods for 38% of the food groups. For the other food groups, the estimates of food consumption by the FFQ were not generally higher or lower than estimates from the 24-hour dietary recalls. Conclusions The FFQ appears to be reasonably valid in the assessment of food consumption of German adults. For some food groups, such as raw and cooked vegetables, relative risks estimates should be interpreted with caution because of the poor ranking agreement.
Lifestyle of UK commercial aircrews relative to air traffic controllers and the general population.
Pizzi, Costanza; Evans, Sally A; De Stavola, Bianca L; Evans, Anthony; Clemens, Felicity; Silva, Isabel dos Santos
2008-10-01
Commercial aircrews are exposed to potential occupational hazards and, recently, epidemiological studies have examined their morbidity and mortality relative to the general population. Aircrews are, however, likely to differ from the general population in several respects which may affect the validity of such comparisons. A cohort of 17,990 commercial aircrews was identified through the United Kingdom (UK) Civil Aviation Authority medical records and is being followed for morbidity and mortality. Demographic, lifestyle, reproductive, and medical characteristics of commercial aircrews were compared with those of: 1) UK air traffic control officers (ATCOs; N = 3386) identified in a similar way as aircrews; and 2) estimates for the UK general population. Aircrews and ATCOs had similar characteristics, except that sex-age-adjusted prevalences for current smoking, obesity, and hypertension were statistically significantly higher in the latter. Both aircrews and ATCOs differed considerably from the general population with, for instance, much lower sex-age-adjusted prevalences of current smoking, obesity, and hypertension but higher levels of regular physical exercise. Age-adjusted fertility rates among female aircrews and ATCOs were only one-third of those in the general population. These differences were slightly attenuated when comparisons with the general population were restricted to its highest socio-economic stratum. The differences between aircrews and the general population are consistent with a strong "healthy worker effect." Aircrews and ATCOs undergo a similar employment selection process and thus taking the latter as the reference population, in addition to the general population, will help to minimize the "healthy worker effect" and gain insight into its biases.
Panaretos, John; Xekalaki, Evdokia
1986-01-01
The binomial and multinomial distributions are, probably, the best known distributions because of their vast number of applications. The present paper examines some generalizations of these distributions with many practical applications. Properties of these generalizations are studied and models giving rise to them are developed. Finally, their relationship to generalized Poisson distributions is examined and limiting cases are given
The Generalized Problematic Internet Use Scale 2: Validation and test of the model to Facebook use.
Assunção, Raquel S; Matos, Paula Mena
2017-01-01
The main goals of the present study were to test the psychometric properties of a Portuguese version of the GPIUS2 (Generalized Problematic Internet Use Scale 2, Caplan, 2010), and to test whether the cognitive-behavioral model proposed by Caplan (2010) replicated in the context of Facebook use. We used a sample of 761 Portuguese adolescents (53.7% boys, 46.3% girls, mean age = 15.8). Our results showed that the data presented an adequate fit to the original model using confirmatory factor analysis. The scale presented also good internal consistency and adequate construct validity. The cognitive-behavioral model was also applicable to the Facebook context, presenting good fit. Consistently with previous findings we found that preference for online social interaction and the use of Facebook to mood regulation purposes, predicted positively and significantly the deficient self-regulation in Facebook use, which in turn was a significant predictor of the negative outcomes associated with this use. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
Optimal spline smoothing of fMRI time series by generalized cross-validation.
Carew, John D; Wahba, Grace; Xie, Xianhong; Nordheim, Erik V; Meyerand, M Elizabeth
2003-04-01
Linear parametric regression models of fMRI time series have correlated residuals. One approach to address this problem is to condition the autocorrelation structure by temporal smoothing. Smoothing splines with the degree of smoothing selected by generalized cross-validation (GCV-spline) provide a method to find an optimal smoother for an fMRI time series. The purpose of this study was to determine if GCV-spline of fMRI time series yields unbiased variance estimates of linear regression model parameters. GCV-spline was evaluated with a real fMRI data set and bias of the variance estimator was computed for simulated time series with autocorrelation structures derived from fMRI data. This study only considered fMRI experimental designs of boxcar type. The results from the real data suggest that GCV-spline determines appropriate amounts of smoothing. The simulations show that the variance estimates are, on average, unbiased. The unbiased variance estimates come at some cost to signal detection efficiency. This study demonstrates that GCV-spline is an appropriate method for smoothing fMRI time series.
Multi-site validation of a soil organic matter model based on generally available input data
Franko, Uwe; Kolbe, Hartmut; Thiel, Enrico; Ließ, Ekkehard
2010-05-01
sources of SOM reproduction. Model results for Corg and Nt have been validated against observed values. The overall result from a model application under practice related conditions shows an acceptable performance of the model. For Corg the mean difference between model and observation is MED=-0.010 and the root mean squared deviation is RMSD=0.158. In case of Nt the results are MED=-0.004 and RMSD=0.012. Basing on this results the CCB model is considered as applicable in advisory service for arable fields on a wide range of site conditions.
Race Matters: The Relation between Race and General Campus Climate.
Reid, Landon D.; Radhakrishnan, Phanikiran
2003-01-01
Examines students' perceptions of racial and academic climate as possible mediators of racial differences in the perception of the university's general campus climate. Students evaluated their perceptions of racial, academic, and general campus climates. As expected, racial minority students, particularly African Americans, perceived more negative…
Disseminating General Relativity for 21st century astronomy
Crosta, Mariateresa
2015-08-01
The talk aims to present two outreach projects - initially developed for the ESA Gaia satellite, a multidisciplinary mission launched on December 19, 2013 - available to the OAD community: NeST and "The Meaning of Light".NeST is an interactive educational tool, that displays how the theory of GR rules the Universe, it creates a performance physically "belonging" to the exhibition space and moving through it, materializing what J.A. Wheeler said "mass tells space-time how to curve, and space-time tells mass how to move"."The Meaning of Light" is a short motion comics, part of an extensive outreach program called "The History of Photons" whose main theme is the story of a beam of stellar photons that, after leaving the progenitor star, propagates through the Universe and, once intercepted come into contact with a team of scientists: here begins their adventure to be taken "back" home and in doing so the scientists, and the spectators, are driven to discover the wonders of which the light are the bearers.The description of the journey of the photons becomes, therefore, an opportunity to easily tell the fascinating topics of Astrophysics and General Relativity, i.e. the complexity and the infinite beauty of the Universe in which we live.For this movie a new theme song was produced, "Singing the Stars", whose refrain (Oh Be A Fine Girl / Guy Kiss Me Little Thing, Yeah) adds to the famous mnemonic for stellar classification (OBAFGKM) the new stellar types LTY discovered in recent years.
PLANCK, the Satellite: a New Experimental Test of General Relativity
Directory of Open Access Journals (Sweden)
Rabounski D.
2008-04-01
Full Text Available If the origin of a microwave background (EMB is the Earth, what would be its density and associated dipole anisotropy measured at different altitudes from the surface of the Earth? The mathematical methods of the General Theory of Relativity are applied herein to answer these questions. The density of the EMB is answered by means of Einstein's equations for the electromagnetic field of the Earth. The dipole anisotropy, which is due to the rapid motion of the source (the Earth in the weak intergalactic field, is analysed by using the geodesic equations for light-like particles (photons, which are mediators for electromagnetic radiation. It is shown that the EMB decreases with altitude so that the density of its energy at the altitude of the COBE orbit (900km is 0.68 times less than that at the altitude of a U2 aeroplane (25km. Furthermore, the density at the 2nd Lagrange point (1.5 million km, the position of the WMAP and PLANCK satellites should be only 10$^{-7}$ of the value detected by a U2 aeroplane or at the COBE orbit. The dipole anisotropy of the EMB doesn't depend on altitude from the surface of the Earth, it should be the same irrespective of the altitude at which measurements are taken. This result is in support to the experimental and observational analysis conducted by P.-M.Robitaille, according to which the 2.7K microwave background, first observed by Penzias and Wilson, is not of cosmic origin, but of the Earth, and is generated by the oceans. WMAP indicated the same anisotropy of the microwave background at the 2nd Lagrange point that near the Earth. Therefore when PLANCK, which is planned on July, 2008, will manifest the 2.7K monopole microwave signal deceased at the 2nd Langrange point, it will be a new experimental verification of Einstein's theory.
PLANCK, the Satellite: a New Experimental Test of General Relativity
Directory of Open Access Journals (Sweden)
Borissova L.
2008-04-01
Full Text Available If the origin of a microwave background (EMB is the Earth, what would be its density and associated dipole anisotropy measured at different altitudes from the surface of the Earth? The mathematical methods of the General Theory of Relativity are applied herein to answer these questions. The density of the EMB is answered by means of Einstein’s equations for the electromagnetic field of the Earth. The dipole anisotropy, which is due to the rapid motion of the source (the Earth in the weak intergalactic field, is analysed by using the geodesic equations for light-like particles (photons, which are mediators for electromagnetic radiation. It is shown that the EMB decreases with altitude so that the density of its energy at the altitude of the COBE orbit (900km is 0.68 times less than that at the altitude of a U2 aeroplane (25 km. Furthermore, the density at the 2nd Lagrange point (1.5 million km, the position of the WMAP and PLANCK satellites should be only 1E-7 of the value detected by a U2 aeroplane or at the COBE orbit. The dipole anisotropy of the EMB doesn’t depend on altitude from the surface of the Earth, it should be the same irrespective of the altitude at which measurements are taken. This result is in support to the experimental and observational analysis conducted by P.-M. Robitaille, according to which the 2.7 K microwave background, first observed by Penzias and Wilson, is not of cosmic origin, but of the Earth, and is generated by the oceans. WMAP indicated the same anisotropy of the microwave background at the 2nd Lagrange point that near the Earth. Therefore when PLANCK, which is planned on July, 2008, will manifest the 2.7 K monopole microwave signal deceased at the 2nd Langrange point, it will be a new experimental verification of Einstein’s theory.
Directory of Open Access Journals (Sweden)
Michele Poletti
2010-04-01
Full Text Available This paper discusses the ecological validity of recently proposed tasks for the assessment of executive functions related to the Orbitofrontal Cortex, in children and adolescents. This topic is discussed considering two conceptually distinct approaches to ecological validity, verisimilitude and veridicality. The issue of ecological validity has been increasingly recognized in child neuropsychology, but an attention to this topic seems to lack in studies that assessed the development of Orbitofrontal cortex-related executive functions in children and adolescents with gambling tasks or delay of gratification tasks. An exception is represented by ADHD population, where specially delay aversion tasks seem to have a good veridicality-oriented ecological validity. The weakness of literature about the ecological validity of these executive measures must encourage to keep in mind ecological validity during the development of new tasks
Directory of Open Access Journals (Sweden)
Min-Woo Jo
2017-01-01
Full Text Available Objectives Few attempts have been made to develop a generic health-related quality of life (HRQoL instrument and to examine its validity and reliability in Korea. We aimed to do this in our present study. Methods After a literature review of existing generic HRQoL instruments, a focus group discussion, in-depth interviews, and expert consultations, we selected 30 tentative items for a new HRQoL measure. These items were evaluated by assessing their ceiling effects, difficulty, and redundancy in the first survey. To validate the HRQoL instrument that was developed, known-groups validity and convergent/discriminant validity were evaluated and its test-retest reliability was examined in the second survey. Results Of the 30 items originally assessed for the HRQoL instrument, four were excluded due to high ceiling effects and six were removed due to redundancy. We ultimately developed a HRQoL instrument with a reduced number of 20 items, known as the Health-related Quality of Life Instrument with 20 items (HINT-20, incorporating physical, mental, social, and positive health dimensions. The results of the HINT-20 for known-groups validity were poorer in women, the elderly, and those with a low income. For convergent/discriminant validity, the correlation coefficients of items (except vitality in the physical health dimension with the physical component summary of the Short Form 36 version 2 (SF-36v2 were generally higher than the correlations of those items with the mental component summary of the SF-36v2, and vice versa. Regarding test-retest reliability, the intraclass correlation coefficient of the total HINT-20 score was 0.813 (p<0.001. Conclusions A novel generic HRQoL instrument, the HINT-20, was developed for the Korean general population and showed acceptable validity and reliability.
Directory of Open Access Journals (Sweden)
José-Manuel de Haro
2014-05-01
Full Text Available Although the study of factors affecting career success has shown connections between biographical and other aspects related to ability, knowledge and personality, few studies have examined the relationship between emotional intelligence and professional success at the initial career stage. When these studies were carried out, the results showed significant relationships between the dimensions of emotional intelligence (emotional self-awareness, self-regulation, social awareness or social skills and the level of professional competence. In this paper, we analyze the relationship between perceived emotional intelligence, measured by the Trait Meta-Mood Scale (TMMS-24 questionnaire, general intelligence assessed by the Cattell factor "g" test, scale 3, and extrinsic indicators of career success, in a sample of 130 graduates at the beginning of their careers. Results from hierarchical regression analysis indicate that emotional intelligence makes a specific contribution to the prediction of salary, after controlling the general intelligence effect. The perceived emotional intelligence dimensions of TMMS repair, TMMS attention and sex show a higher correlation and make a greater contribution to professional success than general intelligence. The implications of these results for the development of socio-emotional skills among University graduates are discussed.
Kong, Feng; You, Xuqun; Zhao, Jingjing
2017-01-01
The Gratitude Questionnaire (GQ; McCullough et al., 2002) is one of the most widely used instruments to assess dispositional gratitude. The purpose of this study was to validate a Chinese version of the GQ by examining internal consistency, factor structure, convergent validity, and measurement invariance across sex. A total of 1151 Chinese adults were recruited to complete the GQ, Positive Affect and Negative Affect Scales, and Satisfaction with Life Scale. Confirmatory factor analysis indicated that the original unidimensional model fitted well, which is in accordance with the findings in Western populations. Furthermore, the GQ had satisfactory composite reliability and criterion-related validity with measures of life satisfaction and affective well-being. Evidence of configural, metric and scalar invariance across sex was obtained. Tests of the latent mean differences found females had higher latent mean scores than males. These findings suggest that the Chinese version of GQ is a reliable and valid tool for measuring dispositional gratitude and can generally be utilized across sex in the Chinese context.
Directory of Open Access Journals (Sweden)
Feng Kong
2017-09-01
Full Text Available The Gratitude Questionnaire (GQ; McCullough et al., 2002 is one of the most widely used instruments to assess dispositional gratitude. The purpose of this study was to validate a Chinese version of the GQ by examining internal consistency, factor structure, convergent validity, and measurement invariance across sex. A total of 1151 Chinese adults were recruited to complete the GQ, Positive Affect and Negative Affect Scales, and Satisfaction with Life Scale. Confirmatory factor analysis indicated that the original unidimensional model fitted well, which is in accordance with the findings in Western populations. Furthermore, the GQ had satisfactory composite reliability and criterion-related validity with measures of life satisfaction and affective well-being. Evidence of configural, metric and scalar invariance across sex was obtained. Tests of the latent mean differences found females had higher latent mean scores than males. These findings suggest that the Chinese version of GQ is a reliable and valid tool for measuring dispositional gratitude and can generally be utilized across sex in the Chinese context.
Construct validity of the instrument DOA: a dialogue about ability related to work.
Linddahl, Iréne; Norrby, Eva; Bellner, Anna-Lena
2003-01-01
This study examined the construct validity of the newly developed instrument A Dialogue About Ability Related To Work (DOA). DOA [18] was developed using concepts from the Model of Human Occupation [20] as theoretical framework. The instrument assumes the assessment of work ability by both the client and the occupational therapist, and is followed by a dialogue which is expected to distinguish possible goal-setting for further rehabilitation [18,19]. Twenty-one professionals and 126 clients from three clinics in Sweden participated in the study. All clients were involved as outpatients in psychiatric work rehabilitation in county councils or community services. Results of a Rasch analysis test indicated that items are well separated and generally work together in five unidimensional continuums to measure work ability. Twenty-nine of 34 items showed goodness-of-fit statistics, which means acceptable infit MnSq values from > or = 0.6 to DOA is a valid instrument in psychiatric work rehabilitation and ought to be useful in the dialogue between occupational therapists and clients about goalsetting and treatment planning.
General Safety and Waste Management Related to SAM
The General Safety and Waste Management page offers section-specific safety and waste management details for chemicals, radiochemicals, pathogens, and biotoxins included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).
Possible Simple Structures of the Universe to Include General Relativity Effects
Directory of Open Access Journals (Sweden)
Corneliu BERBENTE
2017-12-01
Full Text Available The general relativity describes the universe properties, the gravity playing a fundamental role. One uses a metric tensor in a Riemann space, g , which should be in agreement with a mass (or energy tensor in order to satisfy the Einstein equation of the general relativity [1]. This equation contains the Ricci curvature as well. In general, applications are done considering that a chosen metric is valid without region limits. In fact, the density of the energy whose distribution is however unknown is variable in universe; therefore, the metrics need to be adapted to different regions. For this reason one suggests to start with a simple, average mass-energy distribution that could represent in a first step the actual universe. This suggestion is in agreement with the symmetrical distribution of equal spheres existing in a model of the early universe given by one of the authors. Two kinds of distribution are given. The possibility of black holes formation is studied and a criterion is given.
A Test of General Relativity with MESSENGER Mission Data
Genova, A.; Mazarico, E.; Goossens, S. J.; Lemoine, F. G.; Neumann, G. A.; Nicholas, J. B.; Rowlands, D. D.; Smith, D. E.; Zuber, M. T.; Solomon, S. C.
2016-12-01
The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft initiated collection of scientific data from the innermost planet during its first flyby of Mercury in January 2008. After two additional Mercury flybys, MESSENGER was inserted into orbit around Mercury on 18 March 2011 and operated for more than four Earth years through 30 April 2015. Data acquired during the flyby and orbital phases have provided crucial information on the formation and evolution of Mercury. The Mercury Laser Altimeter (MLA) and the radio science system, for example, obtained geodetic observations of the topography, gravity field, orientation, and tides of Mercury, which helped constrain its surface and deep interior structure. X-band radio tracking data collected by the NASA Deep Space Network (DSN) allowed the determination of Mercury's gravity field to spherical harmonic degree and order 100, as well as refinement of the planet's obliquity and estimation of the tidal Love number k2. These geophysical parameters are derived from the range-rate observables that measure precisely the motion of the spacecraft in orbit around the planet. However, the DSN stations acquired two other kinds of radio tracking data, range and delta-differential one-way ranging, which also provided precise measurements of Mercury's ephemeris. The proximity of Mercury's orbit to the Sun leads to a significant perihelion precession, which was used by Einstein as confirmation of general relativity (GR) because of its inconsistency with the effects predicted from classical Newtonian theory. MESSENGER data allow the estimation of the GR parameterized post-Newtonian (PPN) coefficients γ and β. Furthermore, determination of Mercury's orbit also allows estimation of the gravitational parameter (GM) and the flattening (J2) of the Sun. We modified our orbit determination software, NASA GSFC's GEODYN II, to enable simultaneous orbit integration of both MESSENGER and the planet Mercury. The
Person fit and criterion-related validity: an extension of the Schmitt, Cortina, and Whitney study
Meijer, R.R.
1997-01-01
The effect on criterion-related validity of nonfitting response vectors (NRVs) on a predictor test was investigated. Using simulated data, it was shown that there was a substantial decrease in validity when the type of misfit was severe (i.e., guessing the correct answers to all test items), when
De Groot, Sonja; Balvers, Inge J. M.; Kouwenhoven, Sanne M.; Janssen, Thomas W. J.
2012-01-01
The purpose of this study was to investigate the reliability and validity of wheelchair basketball field tests. Nineteen wheelchair basketball players performed 10 test items twice to determine the reliability. The validity of the tests was assessed by relating the scores to the players'
de Groot, Sonja; Balvers, Inge J.M.; Kouwenhoven, Sanne M.; Janssen, Thomas W.J.
The purpose of this study was to investigate the reliability and validity of wheelchair basketball field tests. Nineteen wheelchair basketball players performed 10 test items twice to determine the reliability. The validity of the tests was assessed by relating the scores to the players'
Validity of three screening questions (3Q/TMD) in relation to the DC/TMD.
Lövgren, A; Visscher, C M; Häggman-Henrikson, B; Lobbezoo, F; Marklund, S; Wänman, A
2016-10-01
Temporomandibular disorders (TMD) are common but seem to be largely undetected within general dental care. To improve dentists' awareness of these symptoms, three screening questions (3Q/TMD) have been introduced. Our aim was to validate 3Q/TMD in relation to the diagnostic criteria for TMD (DC/TMD), while taking into account the severity level of the symptoms. The study population consisted of 7831 individuals 20-69 years old, who had their routine dental check-up at the Public Dental Health Service in Västerbotten, Sweden. All patients answered a health declaration, including the 3Q/TMD regarding frequent temporomandibular pain, pain on movement and catching/locking of the jaw. All 3Q-positives (at least one affirmative) were invited for examination in randomised order. For each 3Q-positive, a matched 3Q-negative was invited. In total, 152 3Q-positives and 148 3Q-negatives participated. At examination, participants answered 3Q/TMD a second time, before they were examined and diagnosed according to DC/TMD. To determine symptom's severity, the Graded Chronic Pain Scale and Jaw Functional Limitation Scale-20 (JFLS-20) were used. In total, 74% of 3Q-positives and 16% of 3Q-negatives met the criteria for DC/TMD pain or dysfunction (disc displacements with reduction and degenerative joint disorder were excluded). Fifty-five per cent of 3Q-positives had a TMD diagnosis and CPI score ≥3 or a JFLS-20 score ≥5, compared to 4% of 3Q-negatives. The results show that the 3Q/TMD is an applicable, cost-effective and valid tool for screening a general adult population to recognise patients in need of further TMD examination and management. © 2016 John Wiley & Sons Ltd.
Bieliński Henryk
2016-01-01
The current paper presents the experimental validation of the generalized model of the two-phase thermosyphon loop. The generalized model is based on mass, momentum, and energy balances in the evaporators, rising tube, condensers and the falling tube. The theoretical analysis and the experimental data have been obtained for a new designed variant. The variant refers to a thermosyphon loop with both minichannels and conventional tubes. The thermosyphon loop consists of an evaporator on the low...
Probing Strong-field General Relativity with Gravitational Waves
Pretorius, Frans
We are on the verge of a new era in astrophysics as a world-wide effort to observe the universe with gravitational waves takes hold---ground based laser interferometers (Hz to kHz), pulsar timing (micro to nano Hz), measurements of polarization of the cosmic microwave background (sub-nano Hz), and the planned NASA/ESA mission LISA (.1 mHz to .1 Hz). This project will study the theoretical nature of gravitational waves (GWs) emitted by two sources in the LISA band, namely supermassive-black-hole (SMBH) binary mergers, and extreme-mass-ratio-inspirals (EMRI's)---the merger of a stellar mass black hole, neutron star, or white dwarf with a SMBH. The primary goal will be to ascertain how well LISA, by observing these sources, could answer the following related questions about the fundamental nature of strong-field gravity: Does Einstein's theory of general relativity (GR) describe the geometry of black holes in the universe? What constraints can GW observations of SMBH mergers and EMRIs place on alternative theories of gravity? If there are deviations from GR, are there statistics that could give indications of a deviation if sources are detected using a search strategy based solely on GR waveforms? The primary reasons for focusing on LISA sources to answer these questions are (a) binary SMBH mergers could be detected by LISA with exquisitely high signal-to- noise, allowing enough parameters of the system to be accurately extracted to perform consistency checks of the underlying theory, (b) EMRIs will spend numerous orbits close to the central black hole, and thus will be quite sensitive to even small near-horizon deviations from GR. One approach to develop the requisite knowledge and tools to answer these questions is to study a concrete, theoretically viable alternative to GR. We will focus on the dynamical variant of Chern-Simons modified gravity (CSMG), which is interesting for several reasons, chief among which are (1) that CSMG generically arises in both string
Directory of Open Access Journals (Sweden)
Jerome I. Rotgans
2015-12-01
Conclusion and relevance: The results suggest that the IIQ is a reliable and valid instrument to measure individual interest across different disciplines and demonstrated adequate predictive validity for cognitive engagement and on-task behaviors and attitudes. The IIQ fills the gap in the literature for a generic instrument to measure individual interest.
It's All Relative: A Validation of Radiation Quality Comparison Metrics
Chappell, Lori J.; Milder, Caitlin M.; Elgart, S. Robin; Semones, Edward J.
2017-01-01
The difference between high-LET and low-LET radiation is quantified by a measure called relative biological effectiveness (RBE). RBE is defined as the ratio of the dose of a reference radiation to that of a test radiation to achieve the same effect level, and thus, is described either as an iso-effector dose-to-dose ratio. A single dose point is not sufficient to calculate an RBE value; therefore, studies with only one dose point usually calculate an effect-to-effect ratio. While not formally used in radiation protection, these iso-dose values may still be informative. Shuryak, et al 2017 investigated the use of an iso-dose metric termed "radiation effects ratio" (RER) and used both RBE and RER to estimate high-LET risks. To apply RBE or RER to risk prediction, the selected metric must be uniquely defined. That is, the calculated value must be consistent within a model given a constant set of constraints and assumptions, regardless of how effects are defined using statistical transformations from raw endpoint data. We first test the RBE and the RER to determine whether they are uniquely defined using transformations applied to raw data. Then, we test whether both metrics can predict heavy ion response data after simulated effect size scaling between human populations or when converting animal to human endpoints.
Langballe, Ellen Melbye; Falkum, Erik; Innstrand, Siw Tone; Aasland, Olaf Gjerlow
2006-01-01
The Maslach Burnout Inventory--General Survey (MBI-GS) is designed to measure the three subdimensions (exhaustion, cynicism, and professional efficacy) of burnout in a wide range of occupations. This article examines the factorial validity of the MBI-GS across eight different occupational groups in Norway: lawyers, physicians, nurses, teachers,…
Lake, Kayll
2010-12-01
, Hoenselaers C and Herlt E 2003 Exact Solutions of Einstein's Field Equations (Second Edition) (Cambridge: Cambridge University Press) [2] Pretorius F and Israel W 1998 Class. Quantum Grav.15 2289 [3] Wiltshire D, Visser M and Scott S (ed) 2008 The Kerr Spacetime: Rotating Black Holes in General Relativity (Cambridge: Cambridge University Press) [4] Coley A, Hervik S and Pelavas N 2009 Class. Quantum Grav. 26 025013 [5] Plebański J and Krasiński A 2006 An Introduction to General Relativity and Cosmology (Cambridge: Cambridge University Press)
Entropic uncertainty relation based on generalized uncertainty principle
Hsu, Li-Yi; Kawamoto, Shoichi; Wen, Wen-Yu
2017-09-01
We explore the modification of the entropic formulation of uncertainty principle in quantum mechanics which measures the incompatibility of measurements in terms of Shannon entropy. The deformation in question is the type so-called generalized uncertainty principle that is motivated by thought experiments in quantum gravity and string theory and is characterized by a parameter of Planck scale. The corrections are evaluated for small deformation parameters by use of the Gaussian wave function and numerical calculation. As the generalized uncertainty principle has proven to be useful in the study of the quantum nature of black holes, this study would be a step toward introducing an information theory viewpoint to black hole physics.
Constraining the angular momentum of the Sun with planetary orbital motions and general relativity
Iorio, Lorenzo
2011-01-01
The angular momentum of a star is an important astrophysical quantity related to its internal structure, formation and evolution. On average, helioseismology yields S = 1.92 10^41 kg m^2 s^-1 for the angular momentum of the Sun. We constrain it in a model-independent, dynamical way by using the gravitomagnetic Lense-Thirring effect predicted by general relativity for the orbit of a test particle moving around a central rotating body. The correction to the standard Einsteinian/Newtonian precession of the longitude of the perihelion $ of Mercury, recently inferred by a team of astronomers from a fit of dynamical models of the forces acting on the planets of the solar system to a long data record, amounts to 0.4 +/- 0.6 mas cty^-1. The modeled forces did not include the Lense-Thirring effect itself, which is expected to be as large as -2.0 mas cty^-1 for the perihelion of Mercury from helioseismological values of S?. By assuming the validity of general relativity, from its theoretical prediction for the gravitom...
Lee, Dongseop; Cho, Bongsoon; Seo, Jeongil; Lee, Khan-Pyo; Choi, Jang-Ho
2014-02-01
This study examined the discriminant and criterion-related validity of the Relative Deprivation Scale. The data were collected from 151 Korean employees who had recently experienced a merger and acquisition. The results of confirmatory factor analysis revealed that the two dimensions of relative deprivation (egoistic and fraternal relative deprivation) are clearly distinguishable from other conceptually related variables, such as negative affectivity, resistance to change, overall job dissatisfaction, and distributive justice. In addition, egoistic relative deprivation made a unique incremental contribution to explaining employee turnover intention beyond the contribution of conceptually related variables, while fraternal relative deprivation did not.
Gleason, Philip M; Harris, Jeffrey; Sheean, Patricia M; Boushey, Carol J; Bruemmer, Barbara
2010-03-01
This is the sixth in a series of monographs on research design and analysis. The purpose of this article is to describe and discuss several concepts related to the measurement of nutrition-related characteristics and outcomes, including validity, reliability, and diagnostic tests. The article reviews the methodologic issues related to capturing the various aspects of a given nutrition measure's reliability, including test-retest, inter-item, and interobserver or inter-rater reliability. Similarly, it covers content validity, indicators of absolute vs relative validity, and internal vs external validity. With respect to diagnostic assessment, the article summarizes the concepts of sensitivity and specificity. The hope is that dietetics practitioners will be able to both use high-quality measures of nutrition concepts in their research and recognize these measures in research completed by others. Copyright 2010 American Dietetic Association. Published by Elsevier Inc. All rights reserved.
Personality Factors Related to Career Satisfaction among General Practitioners.
Schwartz, Robert H.; Shenoy, Sunil
1994-01-01
A survey of 150 general practice dentists examined the relationship between 6 career interests (scientific, artistic, social, enterprising, conventional, technical) and career satisfaction. Results are presented and compared with findings of other studies of dental students and practitioners. Results suggest that satisfied dentists tended to like…
Cooperative Work Education in Diversified Occupations. General Related Curriculum Guide.
Brysgel, David
This guide is intended as a working document for coordinators of cooperative work education in diversified occupations. It contains materials for use in providing students with general classroom instruction concurrent with on-the-job training. The following topics are covered in the individual units in the first-year curriculum: the cooperative…
Einstein's Unification: General Relativity and the Quest for Mathematical Naturalness
van Dongen, J.A.E.F.
2002-01-01
The aim of the thesis has been to understand Einstein's development and see the historical coherence in his later attitude in physics. The lesson we learned has been straightforward: the key that unlocks the later Einstein lies in the road by which he arrived at the field equations of general
A chiral alternative to the vierbein field in general relativity
Hooft, G. 't
1991-01-01
An alternative to the usual vierbein field in a (3 + 1)-dimensional (euclidean) space-time is proposed such that the internal index takes only three values and the external is a double: ea = −ea. In flat space-time this field reduces to the self-dual generalized Levi-Civita symbol a. Like the
Fundamental optimal relation of a generalized irreversible Carnot ...
Indian Academy of Sciences (India)
The effects of heat transfer laws and various loss terms are analysed. The heating load vs. COP characteristic of a generalized irreversible Carnot heat pump is a parabolic-like curve, which is consistent with the experimental result of thermoelectric heat pump. The obtained results include those obtained in many literatures ...
Cancer-related false knowledge in relatives of cancer patients and the general public.
Turhal, N S; Dane, F; Ulus, C; Sari, S; Senturk, N; Bingol, D
2010-01-01
Although there are many myths about cancer in Turkey, there is no study evaluating Turkish public's knowledge about cancer. The goals of our research were to: 1) measure the extent of knowledge of cancer among the Turkish public; 2) determine the differences in extent of cancer-related knowledge between participants who have relatives with cancer and those who do not; and 3) determine the sources of knowledge possessed. Data were obtained from a total of 415 participants (244 female, 171 male), all of them sitting at the Marmara University Faculty of Medicine Hospital (MUFMH) outpatient clinic waiting area for non-cancer-related reasons. Each participant completed a 3-part questionnaire. Appropriate statistical tests were used for comparison. The mean age was 41 years. Of 415 participants, 65.3% stated that they had one or more cancer patient in their immediate family; 70.1% of the participants had a high-school education or greater. The questionnaire showed that, depending on the question, anywhere from 1.7% to 88.5% of the general public possesses some false information; furthermore, the difference in accuracy between relatives of cancer patients and non-relatives was marginal. Only 3 specific questions, related to the following ideas, rendered answers that were statistically significantly different between these 2 groups: breast cancer is only seen in females (p knowledge about cancer was unacceptably high in our cohort. Broader efforts should be made to inform the Turkish public about cancer.
Schembre, Susan M; Geller, Karly S
2011-12-01
This study evaluates the 16-item, four-factor Weight-Related Eating Questionnaire (WREQ), which assesses theory-based aspects of eating behavior, across diverse, nonclinical subgroups. A total of 621 men and women aged 18-81 years (34.3 ± 16.4) with a mean BMI of 25.7 ± 6.1 kg/m(2) (range 15.5-74.1 kg/m(2)) were recruited from general education classes at the University of Hawai'i, Manoa and an online survey panel of Hawai'i residents to complete a web-based survey. Participants were predominantly white (23%), Asian/Asian-mix (42%), or Native Hawaiian/Pacific Islander (18%). The WREQ's factor structure was successfully replicated by confirmatory factor analysis (CFA) for the entire sample and by weight status, gender, age, and race with strong internal consistency. Four-week test-retest reliability (n = 31) for the subscales was excellent with interclass correlations of 0.849-0.932. Tests of population invariance confirmed the generalizability of the WREQ across all subgroups having provided no evidence that the factor structure, factor loadings, or indicator intercepts varied significantly between the groups. Multivariate regression analyses showed that emotional eating was independently associated with BMI (β = 0.272, P model demonstrated very good construct validity, confirming the unbiased generalizability of the WREQ measure across sex, age, race, and BMI subgroups, and excellent criterion-related validity with respect to current BMI, weight change, and weight control status.
Hoots, F. R.; Fitzpatrick, P. M.
1979-01-01
The classical Poisson equations of rotational motion are used to study the attitude motions of an earth orbiting, rapidly spinning gyroscope perturbed by the effects of general relativity (Einstein theory). The center of mass of the gyroscope is assumed to move about a rotating oblate earth in an evolving elliptic orbit which includes all first-order oblateness effects produced by the earth. A method of averaging is used to obtain a transformation of variables, for the nonresonance case, which significantly simplifies the Poisson differential equations of motion of the gyroscope. Long-term solutions are obtained by an exact analytical integration of the simplified transformed equations. These solutions may be used to predict both the orientation of the gyroscope and the motion of its rotational angular momentum vector as viewed from its center of mass. The results are valid for all eccentricities and all inclinations not near the critical inclination.
National Research Council Canada - National Science Library
Pfeiffer, Nils; Martínez, Vania; Mearns, Jack; Catanzaro, Salvatore J; Rojas, Graciela; Backenstrass, Matthias; Kaemmerer, Annette
2012-01-01
...-S) and tests the reliability and the validity of the new questionnaire. A sample of 360 students from Chile completed the NMR-S along with instruments measuring depressive symptoms, social desirability, coping, and emotion regulation...
Directory of Open Access Journals (Sweden)
Eldesoky E. Afify
2013-05-01
Full Text Available In this article, some recurrence relations of inverse and ratio moments for generalized order statistics from doubly truncated and non-truncated generalized exponential distribution are derived. From our results, we deduce the recurrence relations for single and product moments of generalized order statistics from general class distribution obtained by Haseeb and Hassan (2004, also we deduce the recurrence relations for single and product moments of order statistics from generalized exponential distribution obtained by Saran and Pushkarna (2000.
Momentum in General Relativity: Local versus Quasilocal Conservation Laws
Epp, Richard J; Mann, Robert B
2013-01-01
We construct a general relativistic conservation law for linear and angular momentum for matter and gravitational fields in a finite volume of space that does not rely on any spacetime symmetries. This work builds on our previous construction of a general relativistic energy conservation law with the same features. Our approach uses the Brown and York quasilocal stress-energy-momentum tensor for matter and gravitational fields, plus the concept of a rigid quasilocal frame (RQF) introduced in previous work. The RQF approach allows us to construct, in a generic spacetime, frames of reference whose boundaries are rigid (their shape and size do not change with time), and that have precisely the same six arbitrary time-dependent degrees of freedom as the accelerating and tumbling rigid frames we are familiar with in Newtonian mechanics. These RQFs, in turn, give rise to a completely general conservation law for the six components of momentum (three linear and three angular) of a finite system of matter and gravita...
Pailhez, Guillem; Castaño, Juan; Rosado, Silvia; Ballester, M Del Mar; Vendrell, Cristina; Canale, Francisco; Bulbena, Antonio
2017-12-01
To develop and validate the TOPYPS scale, an instrument designed to: (i)detect with a high degree of suspicion the most frequent functional pathologies according to standard diagnostic criteria, and (ii)to assess the physical health in the general population quickly, comprehensive and reliable. Validation of a scale. Primary Care Centre, Barcelona. The scale was administered to 67 randomly selected adults. TOPYPS scale was administered to 67 adults randomly selected from a primary care setting in Barcelona, Spain. TOPYPS has six sections based on body systems, each one scored according to the degree of interference in daily activity, type of treatment received, and prognostic of the reported illnesses in each section. Test-retest reliability completions were on two separate occasions one week apart. Validity was then tested by comparing the results with the clinical examination conducted by two different specialists in general practice (gold standard). Repeatability (test-retest) and inter-rater agreement for each of the six sections and for the total score were satisfactory. Validity was acceptable both for content and construct, according to their correlation with the gold standard. TOPYPS displayed good psychometrical properties. It is a suitable tool to detect and measure functional and organic diseases in general population. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.
Directory of Open Access Journals (Sweden)
Brand Caroline A
2009-11-01
Full Text Available Abstract Background Community based prevalence for diabetes related foot disease (DRFD has been poorly quantified in Australian populations. The aim of this study was to develop and validate a survey tool to facilitate collection of community based prevalence data for individuals with DRFD via telephone interview. Methods Agreed components of DRFD were identified through an electronic literature search. Expert feedback and feedback from a population based construction sample were sought on the initial draft. Survey reliability was tested using a cohort recruited through a general practice, a hospital outpatient clinic and an outpatient podiatry clinic. Level of agreement between survey findings and either medical record or clinical assessment was evaluated. Results The Questionnaire for Diabetes Related Foot Disease (Q-DFD comprised 12 questions aimed at determining presence of peripheral sensory neuropathy (PN and peripheral vascular disease (PVD, based on self report of symptoms and/or clinical history, and self report of foot ulceration, amputation and foot deformity. Survey results for 38 from 46 participants demonstrated agreement with either clinical assessment or medical record (kappa 0.65, sensitivity 89.0%, and specificity 77.8%. Correlation for individual survey components was moderate to excellent. Inter and intrarater reliability and test re-test reliability was moderate to high for all survey domains. Conclusion The development of the Q-DFD provides an opportunity for ongoing collection of prevalence estimates for DRFD across Australia.
Maraz, Aniko; Eisinger, Andrea; Hende, Borbála; Urbán, Róbert; Paksi, Borbála; Kun, Bernadette; Kökönyei, Gyöngyi; Griffiths, Mark D; Demetrovics, Zsolt
2015-02-28
Due to the problems of measurement and the lack of nationally representative data, the extent of compulsive buying behaviour (CBB) is relatively unknown. The validity of three different instruments was tested: Edwards Compulsive Buying Scale (ECBS; Edwards, E.A., 1993. Development of a new scale for measuring compulsive buying behaviour. Financial Counseling and Planning. 4, 67-85), Questionnaire About Buying Behavior (QABB; Lejoyeux, M., Ades, J., 1994. Les achats pathologiques: une addiction comportementale. Neuro-Psy. 9, 25-32.) and Richmond Compulsive Buying Scale (RCBS; Ridgway, N.M., Kukar-Kinney, M., Monroe, K.B., 2008. An expanded conceptualization and a new measure of compulsive buying. Journal of Consumer Research. 35, 622-639.) using two independent samples. One was nationally representative of the Hungarian population (N=2710) while the other comprised shopping mall customers (N=1447). As a result, a new, four-factor solution for the ECBS was developed (Edwards Compulsive Buying Scale Revised (ECBS-R)), and confirmed the other two measures. Additionally, cut-off scores were defined for all measures. Results showed that the prevalence of CBB is 1.85% (with QABB) in the general population but significantly higher in shopping mall customers (8.7% with ECBS-R, 13.3% with QABB and 2.5% with RCBS-R). Conclusively, due to the diversity of content, each measure identifies a somewhat different CBB group. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Camilleri, Géraldine M; Méjean, Caroline; Bellisle, France; Andreeva, Valentina A; Sautron, Valérie; Hercberg, Serge; Péneau, Sandrine
2015-01-01
Intuitive eating is an adaptive dietary behavior that emphasizes eating in response to physiological hunger and satiety cues. The Intuitive Eating Scale-2 (IES-2) measures such attitudes and behaviors. The aim of the present study was to adapt the IES-2 to the French context and to test its psychometric properties in 335 women and 297 men participating in the NutriNet-Santé study. We evaluated the construct validity of the IES-2 by testing hypotheses with regard to its factor structure, relationships with scores of the revised 21-item Three Factor Eating Questionnaire and the Center for Epidemiologic Studies Depression scale, and differences between "a priori" relevant subgroups. First, the exploratory factor analysis revealed three main dimensions: Eating for Physical Rather than Emotional Reasons, Reliance on Hunger and Satiety Cues, and Unconditional Permission to Eat. Second-order confirmatory factor analysis upheld the 3-factor solution influenced by a broader intuitive eating dimension. IES-2 total score was negatively related to cognitive restraint (r = -0.31, P eating (r = -0.58, P eating (r = -0.40, P Eating for Physical Reasons, and Unconditional Permission to Eat subscales. Current or former dieters had lower scores on the IES-2 total scale and on all subscales than did those who had never dieted (all P intuitive eating behaviors in empirical and epidemiological studies in the general population. Copyright © 2014 Elsevier Ltd. All rights reserved.
Nonextensive kinetic theory and H-theorem in general relativity
Santos, A. P.; Silva, R.; Alcaniz, J. S.; Lima, J. A. S.
2017-11-01
The nonextensive kinetic theory for degenerate quantum gases is discussed in the general relativistic framework. By incorporating nonadditive modifications in the collisional term of the relativistic Boltzmann equation and entropy current, it is shown that Tsallis entropic framework satisfies a H-theorem in the presence of gravitational fields. Consistency with the 2nd law of thermodynamics is obtained only whether the entropic q-parameter lies in the interval q ∈ [ 0 , 2 ] . As occurs in the absence of gravitational fields, it is also proved that the local collisional equilibrium is described by the extended Bose-Einstein (Fermi-Dirac) q-distributions.
Directory of Open Access Journals (Sweden)
Daniel Mayorga-Vega
2014-03-01
Full Text Available The main purpose of the present meta-analysis was to examine the scientific literature on the criterion-related validity of sit-and-reach tests for estimating hamstring and lumbar extensibility. For this purpose relevant studies were searched from seven electronic databases dated up through December 2012. Primary outcomes of criterion-related validity were Pearson´s zero-order correlation coefficients (r between sit-and-reach tests and hamstrings and/or lumbar extensibility criterion measures. Then, from the included studies, the Hunter- Schmidt´s psychometric meta-analysis approach was conducted to estimate population criterion- related validity of sit-and-reach tests. Firstly, the corrected correlation mean (rp, unaffected by statistical artefacts (i.e., sampling error and measurement error, was calculated separately for each sit-and-reach test. Subsequently, the three potential moderator variables (sex of participants, age of participants, and level of hamstring extensibility were examined by a partially hierarchical analysis. Of the 34 studies included in the present meta-analysis, 99 correlations values across eight sit-and-reach tests and 51 across seven sit-and-reach tests were retrieved for hamstring and lumbar extensibility, respectively. The overall results showed that all sit-and-reach tests had a moderate mean criterion-related validity for estimating hamstring extensibility (rp = 0.46-0.67, but they had a low mean for estimating lumbar extensibility (rp = 0. 16-0.35. Generally, females, adults and participants with high levels of hamstring extensibility tended to have greater mean values of criterion-related validity for estimating hamstring extensibility. When the use of angular tests is limited such as in a school setting or in large scale studies, scientists and practitioners could use the sit-and-reach tests as a useful alternative for hamstring extensibility estimation, but not for estimating lumbar extensibility.
Bártolo, Ana; Monteiro, Sara; Pereira, Anabela
2017-09-28
: The Generalized Anxiety Disorder 7-item (GAD-7) scale has been presented as a reliable and valid measure to assess generalized anxiety symptoms in several clinical settings and among the general population. However, some researches did not support the original one-dimensional structure of the GAD-7 tool. Our main aim was to examine the factor structure of GAD-7 comparing the one-factor model fit with a two-factor model (3 somatic nature symptoms and 4 cognitive-emotional nature symptoms) in a sample of college students. This validation study with data collected cross-sectionally included 1,031 Portuguese college students attending courses in the six schools of the Polytechnic Institute of Coimbra, Coimbra, Portugal. Measures included the GAD-7, Hospital Anxiety and Depression Scale (HADS) and the University Student Risk Behaviors Questionnaire. Confirmatory factor analysis (CFA) procedures confirmed that neither factor structure was well fitting. Thus, a modified single factor model allowing the error terms of items associated with relaxing difficulties and irritability to covary was an appropriate solution. Additionally, this factor structure revealed configural and metric invariance across gender. A good convergent validity was found by correlating global anxiety and depression. However, this measure showed a weak association with consumption behaviors. Our results are relevant to clinical practice, since the comprehensive approach to GAD-7 contributes to knowing generalized anxiety symptoms trajectory and their correlates within the university setting.
Directory of Open Access Journals (Sweden)
Ana Bártolo
2017-09-01
Full Text Available Abstract: The Generalized Anxiety Disorder 7-item (GAD-7 scale has been presented as a reliable and valid measure to assess generalized anxiety symptoms in several clinical settings and among the general population. However, some researches did not support the original one-dimensional structure of the GAD-7 tool. Our main aim was to examine the factor structure of GAD-7 comparing the one-factor model fit with a two-factor model (3 somatic nature symptoms and 4 cognitive-emotional nature symptoms in a sample of college students. This validation study with data collected cross-sectionally included 1,031 Portuguese college students attending courses in the six schools of the Polytechnic Institute of Coimbra, Coimbra, Portugal. Measures included the GAD-7, Hospital Anxiety and Depression Scale (HADS and the University Student Risk Behaviors Questionnaire. Confirmatory factor analysis (CFA procedures confirmed that neither factor structure was well fitting. Thus, a modified single factor model allowing the error terms of items associated with relaxing difficulties and irritability to covary was an appropriate solution. Additionally, this factor structure revealed configural and metric invariance across gender. A good convergent validity was found by correlating global anxiety and depression. However, this measure showed a weak association with consumption behaviors. Our results are relevant to clinical practice, since the comprehensive approach to GAD-7 contributes to knowing generalized anxiety symptoms trajectory and their correlates within the university setting.
Energy Technology Data Exchange (ETDEWEB)
Reed, B W; Morgan, D G; Okamoto, N L; Kulkarni, A; Gates, B C; Browning, N D
2008-09-16
We recently described a data analysis method for precise ({approx}0.1 {angstrom} random error in the mean for a 200 kV instrument with a 3 {angstrom} FWHM probe size) size measurements of small clusters of heavy metal atoms on supports as imaged in a scanning transmission electron microscope, including an experimental demonstration using clusters that were primarily triosmium or decaosmium. The method is intended for low signal-to-noise ratio images of radiation-sensitive samples. We now present a detailed analysis, including a generalization to address issues of particle anisotropy and biased orientation distributions. In the future, this analysis should enable extraction of shape as well as size information, up to the noise-defined limit of information present in the image. We also present results from an extensive series of simulations designed to determine the method's range of applicability and expected performance in realistic situations. The simulations reproduce the experiments quite accurately, enabling a correction of systematic errors so that only the {approx}0.1 {angstrom} random error remains. The results are very stable over a wide range of parameters. We introduce a variation on the method with improved precision and stability relative to the original version, while also showing how simple diagnostics can test whether the results are reliable in any particular instance.
MacKillop, James; Acker, John D; Bollinger, Jared; Clifton, Allan; Miller, Joshua D; Campbell, W Keith; Goodie, Adam S
2013-09-01
Alcohol misuse is substantially influenced by social factors, but systematic assessments of social network drinking are typically lengthy. The goal of the present study was to provide further validation of a brief measure of social network alcohol use, the Brief Alcohol Social Density Assessment (BASDA), in a sample of emerging adults. Specifically, the study sought to examine the BASDA's convergent, criterion, and incremental validity in relation to well-established measures of drinking motives and problematic drinking. Participants were 354 undergraduates who were assessed using the BASDA, the Alcohol Use Disorders Identification Test (AUDIT), and the Drinking Motives Questionnaire. Significant associations were observed between the BASDA index of alcohol-related social density and alcohol misuse, social motives, and conformity motives, supporting convergent validity. Criterion-related validity was supported by evidence that significantly greater alcohol involvement was present in the social networks of individuals scoring at or above an AUDIT score of 8, a validated criterion for hazardous drinking. Finally, the BASDA index was significantly associated with alcohol misuse above and beyond drinking motives in relation to AUDIT scores, supporting incremental validity. Taken together, these findings provide further support for the BASDA as an efficient measure of drinking in an individual's social network. Methodological considerations as well as recommendations for future investigations in this area are discussed.
Numerical Hydrodynamics in Strong-Field General Relativity
East, William Edward
In this thesis we develop and test methods for numerically evolving hydrodynamics coupled to the Einstein field equations, and then apply them to several problems in gravitational physics and astrophysics. The hydrodynamics scheme utilizes high-resolution shock-capturing techniques with flux corrections while the Einstein equations are evolved in the generalized harmonic formulation using finite difference methods. We construct initial data by solving the constraint equations using a multigrid algorithm with free data chosen based on superposing isolated compact objects. One application we consider is the merger of black hole-neutron star and neutron star-neutron star binaries that form through dynamical capture, as may occur in globular clusters or galactic nuclei. These systems can merge with non-negligible orbital eccentricity and display significant variability in dynamics and outcome as a function of initial impact parameter. We study the electromagnetic and gravitational-wave transients that these mergers may produce and their prospects for being detected with upcoming observations. We also introduce a numerical technique that allows solutions to the full Einstein equations to be obtained for extreme-mass-ratio systems where the spacetime is dominated by a known background solution. This technique is based on using the knowledge of a background solution to subtract off its contribution to the truncation error. We use this to study the tidal effects and gravitational radiation from a solar-type star falling into a supermassive black hole. Finally, we utilize general-relativistic hydrodynamics to study ultrarelativistic black hole formation. We study the head-on collision of fluid particles well within the kinetic energy dominated regime (Lorentz factors of 8-12). We find that black hole formation does occur at energies a factor of a few below simple hoop conjecture estimates. We also find that near the threshold for black hole formation, the collision leads to
General Theory of Relativity - The Power of Speculative Thought
Indian Academy of Sciences (India)
esting document revealing the thoughts and feelings of the great scientist about the beginning of GTR. Einstein wri tes - "Then there occurred to me .... the happiest thought of my life, in the following form. The gravita- tional field has only a relative existence in a very similar. Asit Banerjee retired from. Jadavpur University as a.
A generalized relative total variation method for image smoothing
Liu, Qiegen; Xiong, Biao; Yang, Dingcheng; Zhang, Minghui
2016-01-01
Recently, two piecewise smooth models L0smoothing and relative total variation (RTV) have been proposed for feature/structure-preserving filtering. One is very efficient for tackling image with little texture patterns and the other has appearance performance on image with abundant uniform textural
Malisova, Olga; Bountziouka, Vassiliki; Panagiotakos, Demosthenes B; Zampelas, Antonis; Kapsokefalou, Maria
2012-03-01
There is a need to develop a questionnaire as a research tool for the evaluation of water balance in the general population. The water balance questionnaire (WBQ) was designed to evaluate water intake from fluid and solid foods and drinking water, and water loss from urine, faeces and sweat at sedentary conditions and physical activity. For validation purposes, the WBQ was administrated in 40 apparently healthy participants aged 22-57 years (37.5% males). Hydration indices in urine (24 h volume, osmolality, specific gravity, pH, colour) were measured through established procedures. Furthermore, the questionnaire was administered twice to 175 subjects to evaluate its reliability. Kendall's τ-b and the Bland and Altman method were used to assess the questionnaire's validity and reliability. The proposed WBQ to assess water balance in healthy individuals was found to be valid and reliable, and it could thus be a useful tool in future projects that aim to evaluate water balance.
Ethical leadership: meta-analytic evidence of criterion-related and incremental validity.
Ng, Thomas W H; Feldman, Daniel C
2015-05-01
This study examines the criterion-related and incremental validity of ethical leadership (EL) with meta-analytic data. Across 101 samples published over the last 15 years (N = 29,620), we observed that EL demonstrated acceptable criterion-related validity with variables that tap followers' job attitudes, job performance, and evaluations of their leaders. Further, followers' trust in the leader mediated the relationships of EL with job attitudes and performance. In terms of incremental validity, we found that EL significantly, albeit weakly in some cases, predicted task performance, citizenship behavior, and counterproductive work behavior-even after controlling for the effects of such variables as transformational leadership, use of contingent rewards, management by exception, interactional fairness, and destructive leadership. The article concludes with a discussion of ways to strengthen the incremental validity of EL. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
Matzel, Louis D.; Grossman, Henya; Light, Kenneth; Townsend, David; Kolata, Stefan
2008-01-01
A defining characteristic of age-related cognitive decline is a deficit in general cognitive performance. Here we use a testing and analysis regimen that allows us to characterize the general learning abilities of young (3-5 mo old) and aged (19-21 mo old) male and female Balb/C mice. Animals' performance was assessed on a battery of seven diverse…
Relative age effects in fitness testing in a general school sample: how relative are they?
Veldhuizen, Scott; Cairney, John; Hay, John; Faught, Brent
2015-01-01
When children or adolescents are grouped by age or year of birth, older individuals tend to outperform younger ones. These phenomena are known as relative age effects (RAEs). RAEs may result directly from differences in maturation, but may also be associated with psychological, pedagogic or other factors. In this article, we attempt to quantify RAEs in a simple fitness task and to identify the mechanisms operating. Data come from a 5-year study of 2278 individuals that included repeated administrations of the 20 m shuttle run. We use mixed-effect modelling to characterise change over time and then examine residuals from these models for evidence of an effect for age relative to peers or for season of birth. Age alone appears to account for RAEs in our sample, with no effects for age relative to peers or month of birth. Age grouping produces large disparities for girls under 12, moderate ones for boys of all ages and negligible ones for girls between 12 and 15. RAEs for this task and population appear to arise from simple age differences. Similar methods may be useful in determining whether other explanations of RAEs are necessary in other contexts. Evaluation processes that take age into account have the potential to mitigate RAEs in general settings.
Special relativity in general frames from particles to astrophysics
Gourgoulhon, Éric
2013-01-01
Special relativity is the basis of many fields in modern physics: particle physics, quantum field theory, high-energy astrophysics, etc. This theory is presented here by adopting a four-dimensional point of view from the start. An outstanding feature of the book is that it doesn’t restrict itself to inertial frames but considers accelerated and rotating observers. It is thus possible to treat physical effects such as the Thomas precession or the Sagnac effect in a simple yet precise manner. In the final chapters, more advanced topics like tensorial fields in spacetime, exterior calculus and relativistic hydrodynamics are addressed. In the last, brief chapter the author gives a preview of gravity and shows where it becomes incompatible with Minkowsky spacetime. Well illustrated and enriched by many historical notes, this book also presents many applications of special relativity, ranging from particle physics (accelerators, particle collisions, quark-gluon plasma) to astrophysics (relativistic jets, active g...
General Relativity eliminates Dark Energy, Dark Matter and Universal Expansion
Bartlett, Rodney
2018-01-01
This letter was rejected by International Knowledge Press because "we are unable to conclude that these findings would warrant publication in this journal." The letter is suggesting that dark energy, dark matter and universal expansion are intimately related. However, they aren't viewed as revolutions in cosmology which are essential to a complete understanding of the modern universe. They are instead viewed as properties which need to be added to the cosmos when Einstein...
Kampa, Nele; Köller, Olaf
2016-01-01
National and international large-scale assessments (LSA) have a major impact on educational systems, which raises fundamental questions about the validity of the measures regarding their internal structure and their relations to relevant covariates. Given its importance, research on the validity of instruments specifically developed for LSA is…
General characteristics of relative dispersion in the ocean
Corrado, Raffaele; Lacorata, Guglielmo; Palatella, Luigi; Santoleri, Rosalia; Zambianchi, Enrico
2017-04-01
The multi-scale and nonlinear nature of the ocean dynamics dramatically affects the spreading of matter, like pollutants, marine litter, etc., of physical and chemical seawater properties, and the biological connectivity inside and among different basins. Based on the Finite-Scale Lyapunov Exponent analysis of the largest available near-surface Lagrangian data set from the Global Drifter Program, our results show that, despite the large variety of flow features, relative dispersion can ultimately be described by a few parameters common to all ocean sub-basins, at least in terms of order of magnitude. This provides valuable information to undertake Lagrangian dispersion studies by means of models and/or of observational data. Moreover, our results show that the relative dispersion rates measured at submesoscale are significantly higher than for large-scale dynamics. Auxiliary analysis of high resolution GPS-tracked drifter hourly data as well as of the drogued/undrogued status of the buoys is provided in support of our conclusions. A possible application of our study, concerning reverse drifter motion and error growth analysis, is proposed relatively to the case of the missing Malaysia Airlines MH370 aircraft.
Achieving external validity in home advantage research: generalizing crowd noise effects
Directory of Open Access Journals (Sweden)
Tony D Myers
2014-06-01
Full Text Available Different factors have been postulated to explain the home advantage phenomenon in sport. One plausible explanation investigated has been the influence of a partisan home crowd on sports officials’ decisions. Different types of studies have tested the crowd influence hypothesis including purposefully designed experiments. However, while experimental studies investigating crowd influences have high levels of internal validity, they suffer from a lack of external validity; decision-making in a laboratory setting bearing little resemblance to decision-making in live sports settings. This focused review initially considers threats to external validity in applied and theoretical experimental research. Discussing how such threats can be addressed using representative design by focusing on a recently published study that arguably provides the first experimental evidence of the impact of live crowd noise on officials in sport. The findings of this controlled experiment conducted in a real tournament setting offer some confirmation of the validity of laboratory experimental studies in the area. Finally directions for future research and the future conduct of crowd noise studies are discussed.
Directory of Open Access Journals (Sweden)
Mehdi Rabie
2014-05-01
Full Text Available Background: 4TThe revised version of the Screen for Child Anxiety Related Emotional Disorders (SCARED-41 is a self-report questionnaire that measures symptoms (panic disorder, generalized anxiety disorder, separation anxiety disorder, obsessive-compulsive disorder, school phobia, social phobia of DSM-IV linked anxiety disorders in children with aged 8 to 18 years. The aim of the present study was to examine the validation of the (SCARED-41 in a sample of 300 school children. Materials and Methods:4T After the translation of the original version of the mentioned Scale to Farsi and confirming it by two psychology and English language professors, the final version was administered to 300 students (150 males, 150 females of Isfahan who were selected through stratified-cluster sampling. The age range of the participants was between 19 to 35 years. To assess reliability, internal consistency and split half methods were used. Also, concurrent, validity of convergent and divergent and factorial structure were used to determine validity. Results: 4TThe range of Cronbach’s alpha and retest were from 0.52 to 0.93 for subscale. Also, the coefficients of total Cronbach’s alpha reliability and retest were 0.93, and 0.92 respectively. Moreover, results of the concurrent validity, validity of convergent and divergent and factorial structure showed that (SCARED-41 has satisfactory validity. Conclusion: 4TThe revised version of the SCARED-41 has satisfactory reliability and validity in the sample of Iranian students, and could be used for diagnostic and therapeutic purposes.
Maladaptive Core Beliefs and their Relation to Generalized Anxiety Disorder.
Koerner, Naomi; Tallon, Kathleen; Kusec, Andrea
2015-01-01
Research has demonstrated that individuals with generalized anxiety disorder (GAD) hold unhelpful beliefs about worry, uncertainty, and the problem-solving process. Extant writings (e.g., treatment manuals) also suggest that other types of maladaptive beliefs may characterize those with GAD. However, these other beliefs have received limited empirical attention and are not an explicit component of cognitive theories of GAD. The present study examined the extent to which dysfunctional attitudes, early maladaptive schemas, and broad self-focused and other-focused beliefs explain significant variance in GAD symptoms, over and above negative and positive beliefs about worry, negative beliefs about uncertainty, and negative beliefs about problems. N = 138 participants classified into Probable GAD and Non-GAD groups completed self-report measures. After controlling for trait anxiety and depressive symptoms, only beliefs about worry, negative beliefs about uncertainty, and schemas reflecting unrelenting standards (e.g., "I must meet all my responsibilities all the time"), the need to self-sacrifice (e.g., "I'm the one who takes care of others"), and less positive views of other people and their intentions (e.g., lower endorsement of views such as "other people are fair"), were unique correlates of Probable GAD versus Non-GAD or GAD severity. Theoretical and clinical implications are discussed.
Uniformly rotating, axisymmetric, and triaxial quark stars in general relativity
Zhou, Enping; Tsokaros, Antonios; Rezzolla, Luciano; Xu, Renxin; UryÅ«, KÅji
2018-01-01
Quasiequilibrium models of uniformly rotating axisymmetric and triaxial quark stars are computed in a general-relativistic gravity scenario. The Isenberg-Wilson-Mathews (IWM) formulation is employed and the Compact Object Calculator (cocal) code is extended to treat rotating stars with finite surface density and new equations of state (EOSs). Besides the MIT bag model for quark matter which is composed of deconfined quarks, we examine a new EOS proposed by Lai and Xu that is based on quark clustering and results in a stiff EOS that can support masses up to 3.3 M⊙ in the case we considered. We perform convergence tests for our new code to evaluate the effect of finite surface density in the accuracy of our solutions and construct sequences of solutions for both small and high compactness. The onset of secular instability due to viscous dissipation is identified and possible implications are discussed. An estimate of the gravitational wave amplitude and luminosity based on quadrupole formulas is presented and comparison with neutron stars is discussed.
Directory of Open Access Journals (Sweden)
Patrizia Calella
2017-04-01
Full Text Available Good knowledge of nutrition is widely thought to be an important aspect to maintaining a balanced and healthy diet. The aim of this study was to develop and validate a new reliable tool to measure the general and the sport nutrition knowledge (GeSNK in people who used to practice sports at different levels. The development of (GeSNK was carried out in six phases as follows: (1 item development and selection by a panel of experts; (2 pilot study in order to assess item difficulty and item discrimination; (3 measurement of the internal consistency; (4 reliability assessment with a 2-week test-retest analysis; (5 concurrent validity was tested by administering the questionnaire along with other two similar tools; (6 construct validity by administering the questionnaire to three groups of young adults with different general nutrition and sport nutrition knowledge. The final questionnaire, consisted of 62 items of the original 183 questions. It is a consistent, valid, and suitable instrument that can be applied over time, making it a promising tool to look at the relationship between nutrition knowledge, demographic characteristics, and dietary behavior in adolescents and young adults.
Mayorga-Vega, Daniel; Merino-Marban, Rafael; Viciana, Jesús
2014-01-01
The main purpose of the present meta-analysis was to examine the scientific literature on the criterion-related validity of sit-and-reach tests for estimating hamstring and lumbar extensibility. For this purpose relevant studies were searched from seven electronic databases dated up through December 2012. Primary outcomes of criterion-related validity were Pearson´s zero-order correlation coefficients (r) between sit-and-reach tests and hamstrings and/or lumbar extensibility criterion measures. Then, from the included studies, the Hunter- Schmidt´s psychometric meta-analysis approach was conducted to estimate population criterion- related validity of sit-and-reach tests. Firstly, the corrected correlation mean (rp), unaffected by statistical artefacts (i.e., sampling error and measurement error), was calculated separately for each sit-and-reach test. Subsequently, the three potential moderator variables (sex of participants, age of participants, and level of hamstring extensibility) were examined by a partially hierarchical analysis. Of the 34 studies included in the present meta-analysis, 99 correlations values across eight sit-and-reach tests and 51 across seven sit-and-reach tests were retrieved for hamstring and lumbar extensibility, respectively. The overall results showed that all sit-and-reach tests had a moderate mean criterion-related validity for estimating hamstring extensibility (rp = 0.46-0.67), but they had a low mean for estimating lumbar extensibility (rp = 0. 16-0.35). Generally, females, adults and participants with high levels of hamstring extensibility tended to have greater mean values of criterion-related validity for estimating hamstring extensibility. When the use of angular tests is limited such as in a school setting or in large scale studies, scientists and practitioners could use the sit-and-reach tests as a useful alternative for hamstring extensibility estimation, but not for estimating lumbar extensibility. Key PointsOverall sit
Mayorga-Vega, Daniel; Merino-Marban, Rafael; Viciana, Jesús
2014-01-01
The main purpose of the present meta-analysis was to examine the scientific literature on the criterion-related validity of sit-and-reach tests for estimating hamstring and lumbar extensibility. For this purpose relevant studies were searched from seven electronic databases dated up through December 2012. Primary outcomes of criterion-related validity were Pearson´s zero-order correlation coefficients (r) between sit-and-reach tests and hamstrings and/or lumbar extensibility criterion measures. Then, from the included studies, the Hunter- Schmidt´s psychometric meta-analysis approach was conducted to estimate population criterion- related validity of sit-and-reach tests. Firstly, the corrected correlation mean (rp), unaffected by statistical artefacts (i.e., sampling error and measurement error), was calculated separately for each sit-and-reach test. Subsequently, the three potential moderator variables (sex of participants, age of participants, and level of hamstring extensibility) were examined by a partially hierarchical analysis. Of the 34 studies included in the present meta-analysis, 99 correlations values across eight sit-and-reach tests and 51 across seven sit-and-reach tests were retrieved for hamstring and lumbar extensibility, respectively. The overall results showed that all sit-and-reach tests had a moderate mean criterion-related validity for estimating hamstring extensibility (rp = 0.46-0.67), but they had a low mean for estimating lumbar extensibility (rp = 0. 16-0.35). Generally, females, adults and participants with high levels of hamstring extensibility tended to have greater mean values of criterion-related validity for estimating hamstring extensibility. When the use of angular tests is limited such as in a school setting or in large scale studies, scientists and practitioners could use the sit-and-reach tests as a useful alternative for hamstring extensibility estimation, but not for estimating lumbar extensibility. Key Points Overall sit
easyCBM® Reading Criterion Related Validity Evidence: Grades 2-5. Technical Report #1310
Lai, Cheng-Fei; Alonzo, Julie; Tindal, Gerald
2013-01-01
In this technical report, we present the results of a study to gather criterion-related evidence for Grade 2-5 easyCBM® reading measures. We used correlations to examine the relation between the easyCBM® measures and other published measures with known reliability and validity evidence, including the Gates-MacGinitie Reading Tests and the Dynamic…
easyCBM® Reading Criterion Related Validity Evidence: Grades K-1. Technical Report #1309
Lai, Cheng-Fei; Alonzo, Julie; Tindal, Gerald
2013-01-01
In this technical report, we present the results of a study to gather criterion-related evidence for Grade K-1 easyCBM® reading measures. We used correlations to examine the relation between the easyCBM® measures and other published measures with known reliability and validity evidence, including the Dynamic Indicators of Basic Early Literacy…
Criterion-related validity op Dutch police-selection measures and differences between ethnic groups.
L.A.L. de Meijer (Lonneke); M.Ph. Born (Marise); G. Terlouw (Gert); H.T. van der Molen (Henk)
2008-01-01
textabstractThis study investigated the criterion-related validity of cognitive ability as well as non-cognitive ability measures and differences between ethnic majority (N = 2,365) and minority applicants (N = 682) in Dutch police officer selection. Findings confirmed the relatively low predictive
A criterion-related validity study of the nursing-care dependency (NCD) scale
Dijkstra, A.; Buist, G.; Dassen, Th.W.N.
The purpose of this study was to examine some aspects of the criterion-related validity of the Nursing-Care Dependency (NCD) scale. This 15-item counting scale has recently been developed for assessing the care dependency of demented or mentally handicapped in-patients. Its criterion-related
Multifractal spectrum of phase space related to generalized thermostatistics
Olemskoi, A. I.; Kharchenko, V. O.; Borisyuk, V. N.
2008-03-01
We consider a self-similar phase space with specific fractal dimension d being distributed with spectrum function f(d) . Related thermostatistics is shown to be governed by the Tsallis formalism of the non-extensive statistics, where the non-additivity parameter equals to τ ¯ (q) ≡ 1 / τ(q) > 1, and the multifractal function τ(q) = qdq - f(dq) is the specific heat determined with multifractal parameter q ∈ [ 1 , ∞ ] . At that, the equipartition law is shown to take place. Optimization of the multifractal spectrum function f(d) arrives at the relation between the statistical weight and the system complexity. It is shown that the statistical weight exponent τ(q) can be modeled by hyperbolic tangent deformed in accordance with both Tsallis and Kaniadakis exponential functions to describe arbitrary multifractal phase space explicitly. The spectrum function f(d) is proved to increase monotonically from minimum value f = - 1 at d = 0 to maximum one f = 1 at d = 1. At the same time, the number of monofractals increases with the growth of the phase-space volume at small dimensions d and falls down in the limit d → 1.
On flux integrals for generalized Melvin solution related to simple finite-dimensional Lie algebra
Ivashchuk, V. D.
2017-10-01
A generalized Melvin solution for an arbitrary simple finite-dimensional Lie algebra G is considered. The solution contains a metric, n Abelian 2-forms and n scalar fields, where n is the rank of G. It is governed by a set of n moduli functions H_s(z) obeying n ordinary differential equations with certain boundary conditions imposed. It was conjectured earlier that these functions should be polynomials—the so-called fluxbrane polynomials. These polynomials depend upon integration constants q_s, s = 1,\\dots ,n. In the case when the conjecture on the polynomial structure for the Lie algebra G is satisfied, it is proved that 2-form flux integrals Φ ^s over a proper 2 d submanifold are finite and obey the relations q_s Φ ^s = 4 π n_s h_s, where the h_s > 0 are certain constants (related to dilatonic coupling vectors) and the n_s are powers of the polynomials, which are components of a twice dual Weyl vector in the basis of simple (co-)roots, s = 1,\\dots ,n. The main relations of the paper are valid for a solution corresponding to a finite-dimensional semi-simple Lie algebra G. Examples of polynomials and fluxes for the Lie algebras A_1, A_2, A_3, C_2, G_2 and A_1 + A_1 are presented.
Relative validity of a food frequency questionnaire used in the Inter99 study
DEFF Research Database (Denmark)
Toft, U.; Kristoffersen, Lars; Ladelund, S.
2008-01-01
OBJECTIVE: To evaluate the validity of the Inter99 food frequency questionnaire (FFQ) compared with a 28-days' diet history and biomarkers. SUBJECTS: A random sample of 13 016 individuals were drawn from a general population and invited for a health screening programme. Participation rate was 52.......5%. All high-risk individuals were re-invited for assessment after 1 and 3 years and completed a 198-item FFQ at all three occasions. Participants attending for 3 years follow-up were invited to participate in the validation study, including a 28-days' diet history, a 24-h urine collection and a fasting...
Modeling of charged anisotropic compact stars in general relativity
Energy Technology Data Exchange (ETDEWEB)
Dayanandan, Baiju; Maurya, S.K.; T, Smitha T. [University of Nizwa, Department of Mathematical and Physical Sciences, College of Arts and Science, Nizwa (Oman)
2017-06-15
A charged compact star model has been determined for anisotropic fluid distribution. We have solved the Einstein-Maxwell field equations to construct the charged compact star model by using the radial pressure, the metric function e{sup λ} and the electric charge function. The generic charged anisotropic solution is verified by exploring different physical conditions like causality condition, mass-radius relation and stability of the solution (via the adiabatic index, TOV equations and the Herrera cracking concept). It is observed that the present charged anisotropic compact star model is compatible with the star PSR 1937+21. Moreover, we also presented the EOS ρ = f(p) for the present charged compact star model. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Abade, Gustavo C; Cichocki, Bogdan [Institute of Theoretical Physics, University of Warsaw, Hoza 69, 00-681 Warsaw (Poland); Ekiel-Jezewska, Maria L; Wajnryb, Eligiusz [Institute of Fundamental Technological Research, Polish Academy of Sciences, Pawinskiego 5B, 02-106 Warsaw (Poland); Naegele, Gerhard, E-mail: mekiel@ippt.gov.p [Institut fuer Festkoerperforschung, Forschungszentrum Juelich, D-52425 Juelich (Germany)
2010-08-18
We study the high-frequency limiting shear viscosity, {eta}{sub {infinity}}, of colloidal suspensions of uncharged porous particles. An individual particle is modeled as a uniformly porous sphere with the internal solvent flow described by the Debye-Bueche-Brinkman equation. A precise hydrodynamic multipole method with a full account of many-particle hydrodynamic interactions encoded in the HYDROMULTIPOLE program extended to porous particles, is used to calculate {eta}{sub {infinity}}as a function of porosity and concentration. The second-order virial expansion for {eta}{sub {infinity}}is derived, and its range of applicability assessed. The simulation results are used to test the validity of generalized Stokes-Einstein relations between {eta}{sub {infinity}}and various short-time diffusion coefficients, and to quantify the accuracy of a simplifying cell model calculation of {eta}{sub {infinity}.} An easy-to-use generalized Saito formula for {eta}{sub {infinity}}is presented which provides a good description of its porosity and concentration dependence. (fast track communication)
DEFF Research Database (Denmark)
Nielsen, Tine; Dammeyer, Jesper; Vang, Maria Louison
2017-01-01
Academic Self-Efficacy Scale (GASE) – were analyzed using Rasch measurement models, with data from 1018 Danish university students (psychology and technical), focusing on gender invariance and the sufficiency of the score. The short 4-item GASE scale was found to be essentially objective and construct...... valid and satisfactorily reliable, though differential item functioning was found relative to gender and academic discipline, and can be used to assess students’ general academic self-efficacy. Research on gender and self-efficacy needs to take gender into account and equate scores appropriately......Studies have reported gender differences in academic self-efficacy. However, how and if academic self-efficacy questionnaires are gender-biased has not been psychometrically investigated. The psychometric properties of a general version of The Physics Self-Efficacy Questionnaire – the General...
Physical activity assessment in the general population; validated self-report methods.
Ara, Ignacio; Aparicio-Ugarriza, Raquel; Morales-Barco, David; Nascimento de Souza, Wysllenny; Mata, Esmeralda; González-Gross, Marcela
2015-02-26
Self-reported questionnaires have been commonly used to assess physical activity levels in large cohort studies. As a result, strong and convincing evidences that physical activity can protect health are widely recognized. However, validation studies using objective measures of physical activity or energy expenditure (double labelled water, accelerometers, pedometers, etc.) indicate that the accuracy and precision of survey techniques are limited. Physical activity questionnaires could fail in estimating particularly non-vigorous physical activity. They have a disproportionate focus on volitional type exercise (i.e. biking, jogging, and walking), while not capturing the activities of daily living and low to moderate intensity movements. Energy expenditure estimates from these data are not recommended. On the other hand, despite objective tools should be the measurement of choice to assess PA level, self-reported questionnaires remain valid, and have many advantages. i.e. low costs. These kind of recalls are designed and validated for different age groups and provide value and important information, mainly about physical activity pattern. Future studies will require more precision and accuracy in physical activity measurement than those provided by traditional survey methods. We can conclude that probably a mixed approach that combines both the objective and subjective techniques involving novel devices and electronic capture of physical activity questionnaires will be more effective. Copyright AULA MEDICA EDICIONES 2015. Published by AULA MEDICA. All rights reserved.
Achieving external validity in home advantage research: generalizing crowd noise effects.
Myers, Tony D
2014-01-01
Different factors have been postulated to explain the home advantage phenomenon in sport. One plausible explanation investigated has been the influence of a partisan home crowd on sports officials' decisions. Different types of studies have tested the crowd influence hypothesis including purposefully designed experiments. However, while experimental studies investigating crowd influences have high levels of internal validity, they suffer from a lack of external validity; decision-making in a laboratory setting bearing little resemblance to decision-making in live sports settings. This focused review initially considers threats to external validity in applied and theoretical experimental research. Discussing how such threats can be addressed using representative design by focusing on a recently published study that arguably provides the first experimental evidence of the impact of live crowd noise on officials in sport. The findings of this controlled experiment conducted in a real tournament setting offer a level of confirmation of the findings of laboratory studies in the area. Finally directions for future research and the future conduct of crowd noise studies are discussed.
29 CFR 541.201 - Directly related to management or general business operations.
2010-07-01
... 29 Labor 3 2010-07-01 2010-07-01 false Directly related to management or general business... management or general business operations. (a) To qualify for the administrative exemption, an employee's primary duty must be the performance of work directly related to the management or general business...
Generality of a congruity effect in judgements of relative order.
Liu, Yang S; Chan, Michelle; Caplan, Jeremy B
2014-10-01
The judgement of relative order (JOR) procedure is used to investigate serial-order memory. Measuring response times, the wording of the instructions (whether the earlier or the later item was designated as the target) reversed the direction of search in subspan lists (Chan, Ross, Earle, & Caplan Psychonomic Bulletin & Review, 16(5), 945-951, 2009). If a similar congruity effect applied to above-span lists and, furthermore, with error rate as the measure, this could suggest how to model order memory across scales. Participants performed JORs on lists of nouns (Experiment 1: list lengths = 4, 6, 8, 10) or consonants (Experiment 2: list lengths = 4, 8). In addition to the usual distance, primacy, and recency effects, instructions interacted with serial position of the later probe in both experiments, not only in response time, but also in error rate, suggesting that availability, not just accessibility, is affected by instructions. The congruity effect challenges current memory models. We fitted Hacker's (Journal of Experimental Psychology: Human Learning and Memory, 6(6), 651-675, 1980) self-terminating search model to our data and found that a switch in search direction could explain the congruity effect for short lists, but not longer lists. This suggests that JORs may need to be understood via direct-access models, adapted to produce a congruity effect, or a mix of mechanisms.
Generalized fluctuation relation for power-law distributions
Budini, Adrián A.
2012-07-01
Strong violations of existing fluctuation theorems may arise in nonequilibrium steady states characterized by distributions with power-law tails. The ratio of the probabilities of positive and negative fluctuations of equal magnitude behaves in an anomalous nonmonotonic way [H. Touchette and E. G. D. Cohen, Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.76.020101 76, 020101(R) (2007)]. Here, we propose an alternative definition of fluctuation relation (FR) symmetry that, in the power-law regime, is characterized by a monotonic linear behavior. The proposal is consistent with a large deviationlike principle. As an example, we study the fluctuations of the work done on a dragged particle immersed in a complex environment able to induce power-law tails. When the environment is characterized by spatiotemporal temperature fluctuations, distributions arising in nonextensive statistical mechanics define the work statistics. In that situation, we find that the FR symmetry is solely defined by the average bath temperature. The case of a dragged particle subjected to a Lévy noise is also analyzed in detail.
Solution of Supplee's submarine paradox through special and general relativity
Vieira, R S
2016-01-01
In 1989 Supplee described an apparent relativistic paradox on which a submarine seems to sink in a given frame while floating in another one. If the submarine density is adjusted to be the same as the water density (when both of them are at rest) and then it is put to move, the density of the submarine will become higher than that of the water, thanks to Lorentz contraction, and hence it sinks. However, in the submarine proper frame, is the water that becomes denser, so the submarine supposedly should float and we get a paradox situation. In this paper we analyze the submarine paradox in both a flat and a curved spacetime. In the case of a flat spacetime, we first show that any relativistic force field in special relativity can be written in the Lorentz form, so that it can always be decomposed into a static (electric-like) and a dynamic (magnetic-like) part. Taking into account the gravitomagnetic effects between the Earth and the water, a relativistic formulation of Archimedes principle can be established, ...
Directory of Open Access Journals (Sweden)
Alba Lucero López Díaz
2006-09-01
tools or the validation of theoretical constructs.: Empirical evidence about Orem’s General Theory application shows its importance for the development of nursing knowledge and its convenience for nursing research and practice.
Directory of Open Access Journals (Sweden)
Akl Elie A
2010-03-01
Full Text Available Abstract Background It is arguable that modification of diet, given its potential for positive health outcomes, should be widely advocated and adopted. However, food intake, as a basic human need, and its modification may be accompanied by sensations of both pleasure and despondency and may consequently affect to quality of life (QoL. Thus, the feasibility and success of dietary changes will depend, at least partly, on whether potential negative influences on QoL can be avoided. This is of particular importance in the context of dietary intervention studies and in the development of new food products to improve health and well being. Instruments to measure the impact of nutrition on quality of life in the general population, however, are few and far between. Therefore, the aim of this project was to develop an instrument for measuring QoL related to nutrition in the general population. Methods and results We recruited participants from the general population and followed standard methodology for quality of life instrument development (identification of population, item selection, n = 24; item reduction, n = 81; item presentation, n = 12; pretesting of questionnaire and initial validation, n = 2576; construct validation n = 128; and test-retest reliability n = 20. Of 187 initial items, 29 were selected for final presentation. Factor analysis revealed an instrument with 5 domains. The instrument demonstrated good cross-sectional divergent and convergent construct validity when correlated with scores of the 8 domains of the SF-36 (ranging from -0.078 to 0.562, 19 out of 40 tested correlations were statistically significant and 24 correlations were predicted correctly and good test-retest reliability (intra-class correlation coefficients from 0.71 for symptoms to 0.90. Conclusions We developed and validated an instrument with 29 items across 5 domains to assess quality of life related to nutrition and other aspects of food intake. The instrument
De Groot, Sonja; Balvers, Inge J M; Kouwenhoven, Sanne M; Janssen, Thomas W J
2012-05-01
The purpose of this study was to investigate the reliability and validity of wheelchair basketball field tests. Nineteen wheelchair basketball players performed 10 test items twice to determine the reliability. The validity of the tests was assessed by relating the scores to the players' classification and competition standard, and rating of coach and player. Six field tests' test-retest showed good reliability (Intraclass correlation coefficient (ICC) = 0.80-0.97), while the pass-for-accuracy, free throws, lay-up and spot shot showed weak to moderate reliability (ICC = 0.26-0.67). Most tests showed moderate to good validity (r > 0.60). The results suggest that wheelchair basketball field tests are reliable and valid with the exception of the shooting and passing items, which should be interpreted carefully.
Identifying food-related life style segments by a cross-culturally valid scaling device
DEFF Research Database (Denmark)
Brunsø, Karen; Grunert, Klaus G.
1994-01-01
We present a new view of life style, based on a cognitive perspective, which makes life style specific to certain areas of consumption. The specific area of consumption studied here is food, resulting in a concept of food-related life style. An instrument is developed that can measure food......-related life style in a cross-culturally valid way. To this end, we have col-lected a pool of 202 items, collected data in three countries, and have con-structed scales based on cross-culturally stable patterns. These scales have then been subjected to a number of tests of reliability and vali-dity. We have...
Validity and Reliability Assessment of the Persian Version of Therapy-Related Symptom Checklist.
Mansouri, Ava; Motaghedi, Rozita; Rashidian, Arash; Ashouri, Asieh; Kagrar, Mona; Hajibabaei, Moluk; Gholami, Kheirollah; Ansari, Shahla
2017-05-01
Therapy-related symptom checklist for children (TRSC-C) was developed as a symptom assessment tool in children receiving chemotherapy. The objective of the present study was to evaluate the validity and reliability of the Persian version of TRSC-C. This cross-sectional study was conducted in 2013-2014 in Tehran, Iran. TRSC-C was translated using backward-forward approach. The content validity, face validity, and comprehensiveness were investigated based on the opinion of experts. The item content validity index (I-CVI) and scale content validity index (S-CVI) were calculated by the mean approach and inter-rater agreement. The scale was revised based on the comments from a team of five experts, after which it was evaluated by an additional group of four experts. To assess the inter-rater reliability, two raters filled the scale with 29 and 30 patients in the outpatient clinic of Hazrat-e Ali Asghar Hospital. The Cronbach's alpha was calculated and factor analysis was performed. The scores of content validity were analyzed in Excel. Other statistical analyses were performed using the SPSS software version 20.0. Based on the initial assessment, the S-CVI with less conservative approach was 60% for clarity, 33% for relevancy, and 60% for simplicity. After revising the scale, the S-CVI reached 100%. The comprehensiveness and face validity of the scale were appropriate. The scale was inter-rater reliable and the Cronbach's alpha was 0.803. Eleven subscales were found in the TRSC-C. It is concluded that the Persian TRSC-C is a valid and reliable tool for measuring children symptoms. Availability of a valid and reliable checklist is a fundamental step in monitoring the symptoms of patients while receiving chemotherapy.
Validity and Reliability Assessment of the Persian Version of Therapy-Related Symptom Checklist
Directory of Open Access Journals (Sweden)
Ava Mansouri
2017-05-01
Full Text Available Therapy-related symptom checklist for children (TRSC-C was developed as a symptom assessment tool in children receiving chemotherapy. The objective of the present study was to evaluate the validity and reliability of the Persian version of TRSC-C. This cross-sectional study was conducted in 2013-2014 in Tehran, Iran. TRSC-C was translated using backward-forward approach. The content validity, face validity, and comprehensiveness were investigated based on the opinion of experts. The item content validity index (I-CVI and scale content validity index (S-CVI were calculated by the mean approach and inter-rater agreement. The scale was revised based on the comments from a team of five experts, after which it was evaluated by an additional group of four experts. To assess the inter-rater reliability, two raters filled the scale with 29 and 30 patients in the outpatient clinic of Hazrat-e Ali Asghar Hospital. The Cronbach’s alpha was calculated and factor analysis was performed. The scores of content validity were analyzed in Excel. Other statistical analyses were performed using the SPSS software version 20.0. Based on the initial assessment, the S-CVI with less conservative approach was 60% for clarity, 33% for relevancy, and 60% for simplicity. After revising the scale, the S-CVI reached 100%. The comprehensiveness and face validity of the scale were appropriate. The scale was inter-rater reliable and the Cronbach’s alpha was 0.803. Eleven subscales were found in the TRSC-C. It is concluded that the Persian TRSC-C is a valid and reliable tool for measuring children symptoms. Availability of a valid and reliable checklist is a fundamental step in monitoring the symptoms of patients while receiving chemotherapy.
The criterion-related validity of integrity tests: an updated meta-analysis.
Van Iddekinge, Chad H; Roth, Philip L; Raymark, Patrick H; Odle-Dusseau, Heather N
2012-05-01
Integrity tests have become a prominent predictor within the selection literature over the past few decades. However, some researchers have expressed concerns about the criterion-related validity evidence for such tests because of a perceived lack of methodological rigor within this literature, as well as a heavy reliance on unpublished data from test publishers. In response to these concerns, we meta-analyzed 104 studies (representing 134 independent samples), which were authored by a similar proportion of test publishers and non-publishers, whose conduct was consistent with professional standards for test validation, and whose results were relevant to the validity of integrity-specific scales for predicting individual work behavior. Overall mean observed validity estimates and validity estimates corrected for unreliability in the criterion (respectively) were .12 and .15 for job performance, .13 and .16 for training performance, .26 and .32 for counterproductive work behavior, and .07 and .09 for turnover. Although data on restriction of range were sparse, illustrative corrections for indirect range restriction did increase validities slightly (e.g., from .15 to .18 for job performance). Several variables appeared to moderate relations between integrity tests and the criteria. For example, corrected validities for job performance criteria were larger when based on studies authored by integrity test publishers (.27) than when based on studies from non-publishers (.12). In addition, corrected validities for counterproductive work behavior criteria were larger when based on self-reports (.42) than when based on other-reports (.11) or employee records (.15). (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Generalizations of Hölder’s and Some Related Integral Inequalities on Fractal Space
Directory of Open Access Journals (Sweden)
Guang-Sheng Chen
2013-01-01
Full Text Available Based on the local fractional calculus, we establish some new generalizations of Hölder’s inequality. By using it, some related results on the generalized integral inequality in fractal space are investigated in detail.
Debnath, Ujjal
2010-01-01
We have considered a cosmological model of holographic dark energy interacting with dark matter and another unknown component of dark energy of the universe. We have assumed two interaction terms $Q$ and $Q'$ in order to include the scenario in which the mutual interaction between the two principal components (i.e., holographic dark energy and dark matter) of the universe leads to some loss in other forms of cosmic constituents. Our model is valid for any sign of $Q$ and $Q'$. If $Q
A, Golkari; A, Sabokseir; D, Blane; A, Sheiham; Rg, Watt
2017-06-01
Early childhood is a crucial period of life as it affects one's future health. However, precise data on adverse events during this period is usually hard to access or collect, especially in developing countries. This paper first reviews the existing methods for retrospective data collection in health and social sciences, and then introduces a new method/tool for obtaining more accurate general and oral health related information from early childhood retrospectively. The Early Childhood Events Life-Grid (ECEL) was developed to collect information on the type and time of health-related adverse events during the early years of life, by questioning the parents. The validity of ECEL and the accuracy of information obtained by this method were assessed in a pilot study and in a main study of 30 parents of 8 to 11 year old children from Shiraz (Iran). Responses obtained from parents using the final ECEL were compared with the recorded health insurance documents. There was an almost perfect agreement between the health insurance and ECEL data sets (Kappa value=0.95 and p < 0.001). Interviewees remembered the important events more accurately (100% exact timing match in case of hospitalization). The Early Childhood Events Life-Grid method proved to be highly accurate when compared with recorded medical documents.
Dental treatment under general anaesthetic and children's oral health-related quality of life.
Martins-Junior, Paulo A
2017-10-27
Data sourcesMedline, Scopus and the Web of Science.Study selectionStudies conducted in children under 16 undergoing general anaesthesia having change in oral health-related quality of life were considered. Selection was undertaken by two reviewers independently.Data extraction and synthesisData abstraction was undertaken independently by three groups of two reviewers - discrepancies were resolved by discussion. Study quality was assessed using the Quality Assessment Tool for Studies of Diverse Design (QATSDD).ResultsTwenty studies were included; there were 18 prospective studies, one randomised trial and one secondary analysis study. Most studies used a pre-test-post-test design and all but one used proxy measures of oral health-related quality of life (OHRQoL). All of the studies reported improved OHRQoL overall. However, results suggested that some aspects of OHRQoL may worsen.ConclusionsHeterogeneity of included papers limited the conclusions which could be drawn. Treatment under GA appears to result in overall improvements in proxy-reported OHRQoL; however, there is a need for further high-quality studies employing validated, child-reported measures of OHRQoL.
Mercer, Sterett H.; Martinez, Rebecca S.; Faust, Dennis; Mitchell, Rachel R.
2012-01-01
We investigated the criterion-related validity of four indicators of curriculum-based measurement in writing (WCBM) when using expository versus narrative writing prompts as compared to the validity of passage copying speed. Specifically, we compared criterion-related validity of production-dependent (total words written, correct word sequences),…
Selinger, C P; Eaden, J; Selby, W; Jones, D B; Katelaris, P; Chapman, G; McDonald, C; McLaughlin, J; Leong, R W L; Lal, S
2012-07-01
Inflammatory bowel diseases (IBD) require complex therapeutic decisions and life choices concerning pregnancy, but little is known about patient's knowledge of IBD and its treatment before and during pregnancy. To develop a novel tool (Crohn's and Colitis Pregnancy Knowledge Score 'CCPKnow') to assess knowledge of pregnancy-related issues in IBD. The validated tool was then applied to determine knowledge in patients. Discriminate ability of 'CCPKnow' was validated in four groups with different levels of IBD knowledge. Reliability and readability were tested by Cronbach-α and Flesch-Kencaid. Construct validity was subsequently assessed against general IBD knowledge (CCKnow) in 145 women with IBD. Associations between patient factors and knowledge were studied. Median CCPKnow scores differed significantly between the validation groups (P disease duration and Crohn's disease. Crohn's and Colitis Pregnancy Knowledge Score, a novel knowledge assessment tool of pregnancy and IBD, demonstrated excellent test characteristics. We found that nearly half of the women with IBD had poor knowledge, identifying a pressing need for better education. © 2012 Blackwell Publishing Ltd.
Kalichman, Seth C; Amaral, Christina M; Cherry, Chauncey; Flanagan, Jody; Pope, Howard; Eaton, Lisa; Kalichman, Moira O; Cain, Demetria; Detorio, Mervi; Caliendo, Angela; Schinazi, Raymond F
2008-01-01
Although demonstrated valid for monitoring medication adherence, unannounced pill counts conducted in patients' homes are costly and logistically challenging. Telephone-based unannounced pill counts offer a promising adaptation that resolves most of the limitations of home-based pill counting. We tested the reliability and criterion-related validity of a telephone-based unannounced pill count assessment of antiretroviral adherence. HIV-positive men and women (N = 89) in Atlanta, Georgia, completed a telephone-based unannounced pill count and provided contemporaneous blood specimens to obtain viral loads; 68 participants also received an immediate second pill count conducted during an unannounced home visit. A high degree of concordance was observed between the number of pills counted on the telephone and in the home (intraclass correlation [ICC] = .981, p criterion-related validity. Unannounced telephone-based pill counts offer a feasible objective method for monitoring medication adherence.
DEFF Research Database (Denmark)
Lundstrøm, Sanne Lykke; Edwards, Kasper; Reventlow, Susanne
2014-01-01
In this paper we investigate the association between relational coordination among the practice team in general practice and number of consultations performed in a general practice per staff, i.e. a proxy of productivity. We measured relational coordination using the Relational Coordination Survey...
Regularization and a general linear model for event-related potential estimation.
Kristensen, Emmanuelle; Guerin-Dugué, Anne; Rivet, Bertrand
2017-12-01
The usual event-related potential (ERP) estimation is the average across epochs time-locked on stimuli of interest. These stimuli are repeated several times to improve the signal-to-noise ratio (SNR) and only one evoked potential is estimated inside the temporal window of interest. Consequently, the average estimation does not take into account other neural responses within the same epoch that are due to short inter stimuli intervals. These adjacent neural responses may overlap and distort the evoked potential of interest. This overlapping process is a significant issue for the eye fixation-related potential (EFRP) technique in which the epochs are time-locked on the ocular fixations. The inter fixation intervals are not experimentally controlled and can be shorter than the neural response's latency. To begin, the Tikhonov regularization, applied to the classical average estimation, was introduced to improve the SNR for a given number of trials. The generalized cross validation was chosen to obtain the optimal value of the ridge parameter. Then, to deal with the issue of overlapping, the general linear model (GLM), was used to extract all neural responses inside an epoch. Finally, the regularization was also applied to it. The models (the classical average and the GLM with and without regularization) were compared on both simulated data and real datasets from a visual scene exploration in co-registration with an eye-tracker, and from a P300 Speller experiment. The regularization was found to improve the estimation by average for a given number of trials. The GLM was more robust and efficient, its efficiency actually reinforced by the regularization.
Terluin, B; van Hout, HPJ; van Marwijk, HWJ; Ader, HJ; van der Meer, K; de Haan, M; van Dyck, R
2002-01-01
General practitioners (GPs) are recommended to use DSM-IV criteria to diagnose major depression in daily clinical practice. This implies the assessment of nine depressive symptoms and four additional criteria. A short structured interview has been developed to assess these symptoms and criteria, and
Criterion-related validity of field-based fitness tests in youth: a systematic review.
Castro-Piñero, J; Artero, E G; España-Romero, V; Ortega, F B; Sjöström, M; Suni, J; Ruiz, J R
2010-10-01
The objective of this systematic review was to comprehensively study the criterion-related validity of the existing field-based fitness tests used in children and adolescents. The studies were scored according to the number of subjects, description of the study population and statistical analysis. Each study was classified as high, low and very low quality. Three levels of evidence were constructed: strong evidence, when consistent findings were observed in three or more high quality studies; moderate evidence, when consistent findings were observed in two high quality studies; and limited evidence when consistency of findings and/or the number of studies did not achieve the criteria for moderate. The results of 73 studies (50 of high quality) addressing the criterion-related validity of field-based fitness tests in children and adolescents indicate the following: that there is strong evidence indicating that the 20 m shuttle run test is a valid test to estimate cardiorespiratory fitness, that the hand-grip strength test is a valid measure of musculoskeletal fitness, that skin fold thickness and body mass index are good estimates of body composition, and that waist circumference is a valid measure to estimate central body fat. Moderate evidence was found that the 1-mile run/walk test is a valid test to estimate cardiorespiratory fitness. A large number of other field-based fitness tests presented limited evidence, mainly due to a limited number of studies (one for each test). The results of the present systematic review should be interpreted with caution due to the substantial lack of consistency in reporting and designing the existing validity studies.
The Criterion-Related Validity of a Computer-Based Approach for Scoring Concept Maps
Clariana, Roy B.; Koul, Ravinder; Salehi, Roya
2006-01-01
This investigation seeks to confirm a computer-based approach that can be used to score concept maps (Poindexter & Clariana, 2004) and then describes the concurrent criterion-related validity of these scores. Participants enrolled in two graduate courses (n=24) were asked to read about and research online the structure and function of the heart…
Wendel-Vos, G.C.W.; Schuit, A.J.; Saris, W.H.M.; Kromhout, D.
2003-01-01
Objective: The purpose of this study is to determine reproducibility and relative validity of the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH). Methods: Participants (36 men and 14 women, aged 27-58) were asked to complete the SQUASH twice with an inbetween period of
Validation and verification of agent models for trust: Independent compared to relative trust
Hoogendoorn, M.; Jaffry, S.W.; Maanen, P.P. van
2011-01-01
In this paper, the results of a validation experiment for two existing computational trust models describing human trust are reported. One model uses experiences of performance in order to estimate the trust in different trustees. The second model in addition carries the notion of relative trust.
Cuesta-Vargas, Antonio I; Galan-Mercant, Alejandro; Martín-Borras, Maria Carmen; González-Sánchez, Manuel
2012-12-01
Criterion-related validity of a self-administered questionnaire listed as gold standard requires objective testing. The aim of this study was to analyze the Foot Health Status Questionnaire (FHSQ) using functional variable measures (dynamic plantar pressure and foot strength). A total of 22 elderly healthy participants (13 women and 9 men) were screened by interview and physical examination for foot or gait abnormalities. Foot strength, footprint pressure, and foot health status were measured. All the items of the FHSQ show significant correlation with functional variables, but general foot health shows the highest correlation with the 4 physical variables related to plantar pressure (R2 = 0.741), followed by foot pain (R2 = 0.652). A set of different, directly measured physical variables related to foot strength and plantar pressure significantly correlate with the FHSQ dimensions. Cross-sectional trial.
Validity and reliability of the tuberculosis-related stigma scale version for Brazilian Portuguese.
de Almeida Crispim, Juliane; da Silva, Laís Mara Caetano; Yamamura, Mellina; Popolin, Marcela Paschoal; Ramos, Antônio Carlos Vieira; Arroyo, Luiz Henrique; de Queiroz, Ana Angélica Rêgo; de Souza Belchior, Aylana; Dos Santos, Danielle Talita; Pieri, Flávia Meneguetti; Rodrigues, Ludmila Barbosa Bandeira; Protti, Simone Terezinha; Pinto, Ione Carvalho; Palha, Pedro Fredemir; Arcêncio, Ricardo Alexandre
2017-07-21
Stigma associated with tuberculosis (TB) has been an object of interest in several regions of the world. The behaviour presented by patients as a result of social discrimination has contributed to delays in diagnosis and the abandonment of treatment, leading to an increase in the cases of TB and drug resistance. The identification of populations affected by stigma and its measurement can be assessed with the use of valid and reliable instruments developed or adapted to the target culture. This aim of this study was to analyse the initial psychometric properties of the Tuberculosis-Related Stigma scale in Brazil, for TB patients. The Tuberculosis-Related Stigma scale is a specific scale for measuring stigma associated with TB, originally validated in Thailand. It presents two dimensions to be assessed, namely Community perspectives toward tuberculosis and Patient perspectives toward tuberculosis. The first has 11 items regarding the behaviour of the community in relation to TB, and the second is made up of 12 items related to feelings such as fear, guilt and sorrow in coping with the disease. A pilot test was conducted with 83 TB patients, in order to obtain the initial psychometric properties of the scale in the Brazilian Portuguese version, enabling simulation of the field study. As regards its psychometric properties, the scale presented acceptable internal consistency for its dimensions, with values ≥0.70, the absence of floor and ceiling effects, which is favourable for the property of scale responsiveness, satisfactory converging validity for both dimensions, with values over 0.30 for initial studies, and diverging validity, with adjustment values different from 100%. The results found show that the Tuberculosis-Related Stigma scale can be a valid and reliable instrument for the Brazilian context.
Relative validity of a web-based food frequency questionnaire for Danish adolescents
DEFF Research Database (Denmark)
Bjerregaard, Anne A.; Halldorsson, Thorhallur I; Kampmann, Freja B
2018-01-01
With increased focus on dietary intake among youth and risk of diseases later in life, it is of importance, prior to assessing diet-disease relationships, to examine the validity of the dietary assessment tool. This study's objective was to evaluate the relative validity of a self-administered web...... for energy and within-person variation in the 24HRs had little effect on the magnitude of the correlations for food groups and nutrients. We found overestimation by the FFQ compared with the 24HRs for fish, fruits, vegetables, oils and dressing and underestimation by the FFQ for meat/poultry and sweets...
Measuring leprosy-related stigma - a pilot study to validate a toolkit of instruments.
Rensen, Carin; Bandyopadhyay, Sudhakar; Gopal, Pala K; Van Brakel, Wim H
2011-01-01
Stigma negatively affects the quality of life of leprosy-affected people. Instruments are needed to assess levels of stigma and to monitor and evaluate stigma reduction interventions. We conducted a validation study of such instruments in Tamil Nadu and West Bengal, India. Four instruments were tested in a 'Community Based Rehabilitation' (CBR) setting, the Participation Scale, Internalised Scale of Mental Illness (ISMI) adapted for leprosy-affected persons, Explanatory Model Interview Catalogue (EMIC) for leprosy-affected and non-affected persons and the General Self-Efficacy (GSE) Scale. We evaluated the following components of validity, construct validity, internal consistency, test-retest reproducibility and reliability to distinguish between groups. Construct validity was tested by correlating instrument scores and by triangulating quantitative and qualitative findings. Reliability was evaluated by comparing levels of stigma among people affected by leprosy and community controls, and among affected people living in CBR project areas and those in non-CBR areas. For the Participation, ISMI and EMIC scores significant differences were observed between those affected by leprosy and those not affected (p = 0.0001), and between affected persons in the CBR and Control group (p < 0.05). The internal consistency of the instruments measured with Cronbach's α ranged from 0.83 to 0.96 and was very good for all instruments. Test-retest reproducibility coefficients were 0.80 for the Participation score, 0.70 for the EMIC score, 0.62 for the ISMI score and 0.50 for the GSE score. The construct validity of all instruments was confirmed. The Participation and EMIC Scales met all validity criteria, but test-retest reproducibility of the ISMI and GSE Scales needs further evaluation with a shorter test-retest interval and longer training and additional adaptations for the latter.
Radic-Sestic, Marina; Radovanovic, Vesna; Milanovic-Dobrota, Biljana; Slavkovic, Sanela; Langovic-Milicvic, Ana
2013-01-01
The general objective of this study was to establish the relation between general and special education teachers within teamwork and to define socio-demographic factors that affect teamwork. The sample encompassed 223 general and special education teacher of both genders, age 25 to 60, who are employed in regular elementary schools in Serbia. The…
Indian Academy of Sciences (India)
Page S20: NMR compound 4i. Page S22: NMR compound 4j. General: Chemicals were purchased from Fluka, Merck and Aldrich Chemical Companies. All the products were characterized by comparison of their IR, 1H NMR and 13C NMR spectroscopic data and their melting points with reported values. General procedure ...
1983-09-01
o. *, - . . - . - . 109 ierr Integer variable. SOn return ierr will contain an error code. # ierr-O - No errors occurred. #i err>O - Error(s) in...precision a(ntlimnim),b(ntlm,ntlm),eigen(1) ,work(1) integer ntlmmu,ierr # Solve generalized elgenvalue problem # a*PHI -EIG * b *PHI # to get the neig ...ival) ambda ,vnu,ntotal ,bigm,nobs ,ncons ,mbigm, qplima,qpcons,esigm,tsigza,qrtsil ,istate,istant, nactiv,ntl,ntzu,idifer, neig ,eigen,wrk(w) ,work
On flux integrals for generalized Melvin solution related to simple finite-dimensional Lie algebra
Energy Technology Data Exchange (ETDEWEB)
Ivashchuk, V.D. [VNIIMS, Center for Gravitation and Fundamental Metrology, Moscow (Russian Federation); Peoples' Friendship University of Russia (RUDN University), Institute of Gravitation and Cosmology, Moscow (Russian Federation)
2017-10-15
A generalized Melvin solution for an arbitrary simple finite-dimensional Lie algebra G is considered. The solution contains a metric, n Abelian 2-forms and n scalar fields, where n is the rank of G. It is governed by a set of n moduli functions H{sub s}(z) obeying n ordinary differential equations with certain boundary conditions imposed. It was conjectured earlier that these functions should be polynomials - the so-called fluxbrane polynomials. These polynomials depend upon integration constants q{sub s}, s = 1,.., n. In the case when the conjecture on the polynomial structure for the Lie algebra G is satisfied, it is proved that 2-form flux integrals Φ{sup s} over a proper 2d submanifold are finite and obey the relations q{sub s} Φ{sup s} = 4πn{sub s}h{sub s}, where the h{sub s} > 0 are certain constants (related to dilatonic coupling vectors) and the n{sub s} are powers of the polynomials, which are components of a twice dual Weyl vector in the basis of simple (co-)roots, s = 1,.., n. The main relations of the paper are valid for a solution corresponding to a finite-dimensional semi-simple Lie algebra G. Examples of polynomials and fluxes for the Lie algebras A{sub 1}, A{sub 2}, A{sub 3}, C{sub 2}, G{sub 2} and A{sub 1} + A{sub 1} are presented. (orig.)
Cooper, Sheri L; Pelly, Fiona E; Lowe, John B
2016-05-01
Nutrient profiling (NP) is defined as the science of ranking foods according to their nutritional composition for the purpose of preventing disease or promoting health. The application of NP is ultimately to assist consumers to make healthier food choices, and thus provide a cost effective public health strategy to reduce the incidence of diet-related chronic disease. To our knowledge, no review has assessed the evidence to confirm the validity of NP models. We conducted a systematic review to investigate the construct and criterion-related validity of NP models in ranking food according to their nutritional composition for the purpose of preventing disease and promoting health. We searched peer-reviewed research published to 30 June 2015 and used PUBMED, Global Health (CABI), and SCOPUS databases. Within study bias was assessed using an adapted version of the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies -2) tool for all diagnostic studies and the Cochrane Collaboration's Risk of Bias tool for all non-diagnostic studies. The GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) approach was used to guide our judgement of the quality of the body of evidence for each outcome measure. From a total of 83 studies, 69 confirmed the construct validity of NP models; however most of these studies contained methodological weaknesses. Six studies used objective external measures to confirm the criterion-related validity of NP models; which inherently improved quality. The overall quality of evidence on the accuracy of NP models was judged to be very low to moderate using the GRADE approach. Many carefully designed studies to establish both construct and criterion-related validity are necessary to authenticate the application of NP models and provide the evidence to support the current definition of NP. Copyright © 2016 Elsevier Ltd. All rights reserved.
Development and validation of the Treatment Related Impact Measure of Weight (TRIM-Weight
Directory of Open Access Journals (Sweden)
Lessard Suzanne
2010-02-01
Full Text Available Abstract Background The use of prescription anti-obesity medication (AOM is becoming increasingly common as treatment options grow and become more accessible. However, AOM may not be without a wide range of potentially negative impacts on patient functioning and well being. The Treatment Related Impact Measure (TRIM-Weight is an obesity treatment-specific patient reported outcomes (PRO measure designed to assess the key impacts of prescription anti-obesity medication. This paper will present the validation findings for the TRIM-Weight. Methods The online validation battery survey was administered in four countries (the U.S., U.K., Australia, and Canada. Eligible subjects were over age eighteen, currently taking a prescription AOM and were currently or had been obese during their life. Validation analyses were conducted according to an a priori statistical analysis plan. Item level psychometric and conceptual criteria were used to refine and reduce the preliminary item pool and factor analysis to identify structural domains was performed. Reliability and validity testing was then performed and the minimally importance difference (MID explored. Results Two hundred and eight subjects completed the survey. Twenty-one of the 43 items were dropped and a five-factor structure was achieved: Daily Life, Weight Management, Treatment Burden, Experience of Side Effects, and Psychological Health. A-priori criteria for internal consistency and test-retest coefficients for the total score and all five subscales were met. All pre-specified hypotheses for convergent and known group validity were also met with the exception of the domain of Daily Life (proven in an ad hoc analysis as well as the 1/2 standard deviation threshold for the MID. Conclusion The development and validation of the TRIM-Weight has been conducted according to well-defined principles for the creation of a PRO measure. Based on the evidence to date, the TRIM-Weight can be considered a brief
Yang, Jiao; Ren, Yujia; Liu, Minhui; Wang, Qingyan; Tang, Siyuan
2014-07-01
To investigate the criterion-related validity of Menopause-Specific Quality of Life Questionnaire (MENQOL)-Chinese version and to evaluate the effect of menopausal symptoms on health related quality of life. This study was a cross-sectional survey. Three communities were randomly chosen in Changsha, and then 340 menopausal women aged 45-55 years were randomly chosen from the documented data of the 3 community health service centers. They were required to fill out 4 questionnaires: demographic questionnaire, MENQOL-Chinese version, Kupperman Index (KI) and World Health Organization Quality of Life (WHQOL)-BREF. Correlation analysis was used to measure the criterion-related validity. MENQOL-Chinese version subscales (vasomotor, psycho-social, sexual and physical) and KI total score were positively correlated (r=0.800, 0.751, 0.607, 0.906 respectively); while negatively correlated with WHOQOL-BREF total score (r =-0.694, -0.851, -0.585, -0.873 respectively); MENQOL-Chinese version subscales (vasomotor, psycho-social, sexual and physical) were significantly correlated with WHOQOL-BREF subscales (physical, psychological, social relationship, environment), and the physical domain was the highest among the correlation coefficients (r=-0.915). MENQOL-Chinese version shows relatively high criterion-related validity compared with KI and WHOQOL-BREF, which can be widely used to measure the quality of life of menopause women in China.
Santos, Alda; Castanheira, Filipa; Chambel, Maria José; Amarante, Michael Vieira; Costa, Carlos
2017-07-01
This study validates the Portuguese version of the psychological effects of the relational job characteristics scale among hospital nurses in Portugal and Brazil. Increasing attention has been given to the social dimension of work, following the transition to a service economy. Nevertheless, and despite the unquestionable relational characteristics of nursing work, scarce research has been developed among nurses under a relational job design framework. Moreover, it is important to develop instruments that study the effects of relational job characteristics among nurses. We followed Messick's framework for scale validation, comprising the steps regarding the response process and internal structure, as well as relationships with other variables (work engagement and burnout). Statistical analysis included exploratory factor analysis and confirmatory factor analysis. The psychological effects of the relational job characteristics scale provided evidence of good psychometric properties with Portuguese and Brazilian hospital nurses. Also, the psychological effects of the relational job characteristics are associated with nurses' work-related well-being: positively with work engagement and negatively concerning burnout. Hospitals that foster the relational characteristics of nursing work are contributing to their nurses' work-related well-being, which may be reflected in the quality of care and patient safety. © 2017 John Wiley & Sons Ltd.
The construct validity of the work-related flow inventory in a sample of Australian workers.
Happell, Brenda; Gaskin, Cadeyrn J; Platania-Phung, Chris
2015-01-01
The purpose of this study was to examine the construct validity of the WOrk-reLated Flow inventory (WOLF; Bakker, 2008). This instrument was administered to 711 men and women who were working in Queensland, Australia. The results from the confirmatory factor analysis showed that the WOLF has moderately acceptable construct validity, with the three-factor model being a borderline fit to the data. Tests of the convergent validity of the WOLF yielded satisfactory results. However, the analysis of the discriminant validity of the WOLF showed that the instrument poorly discriminated between work enjoyment and intrinsic work motivation. Follow-up exploratory factor analysis, using recommended procedures for determining the number of factors to extract, revealed a two-factor solution, with the work enjoyment and intrinsic work motivation items loading on the same factor. Drawing on literature on psychological flow and motivation, as well as the findings of the present study, questions are raised over the adequacy of the conceptual basis of the three-factor model of work-related flow, the discriminant validity of the WOLF subscales, and the appropriateness of the wording of several of this measure's items. Using alternative methods and measures to investigate flow in work settings is recommended.
26 CFR 54.4975-1 - General rules relating to excise tax on prohibited transactions.
2010-04-01
... 26 Internal Revenue 17 2010-04-01 2010-04-01 false General rules relating to excise tax on prohibited transactions. 54.4975-1 Section 54.4975-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) PENSION EXCISE TAXES § 54.4975-1 General rules relating to excise tax on prohibite...
General relativity the most beautiful of theories : applications and trends after 100 years
2015-01-01
Generalising Newton's law of gravitation, general relativity is one of the pillars of modern physics. On the occasion of general relativity's centennial, leading scientists in the different branches of gravitational research review the history and recent advances in the main fields of applications of the theory, which was referred to by Lev Landau as “the most beautiful of the existing physical theories”.
ACADEMIC TRAINING LECTURE SERIES: Introduction to General Relativity and Black Holes
2003-01-01
10, 11, 12, 13, 14 February ACADEMIC TRAINING LECTURE SERIES from 11.00 to 12.00 hrs - Auditorium, bldg. 500 Introduction to General Relativity and Black Holes by T.DAMOUR, IHES, Bures-sur-Yvette, F - Physical motivation behind Einstein's theory. - Mathematical formalism of General Relativity. - Experimental confirmations of Einstein's theory. - Introduction to Black Holes physics.
Bignami-Van Assche, S; Chao, L-W; Anglewicz, P; Chilongozi, D; Bula, A
2007-02-01
Understanding HIV risk perception is important for designing appropriate strategies for HIV/AIDS prevention, because these interventions often rely on behaviour modification. A key component of HIV risk perception is the individual's own assessment of HIV status, and the extent to which this assessment is correct. However, this issue has received limited attention. To examine the validity of self-reported likelihood of current HIV infection among the general population in rural Malawi. As part of a panel household survey, data on behaviour and biomarkers were collected for a population-based sample of approximately 3000 respondents in rural Malawi aged > or = 15 years. Information on self-assessed likelihood of currently having HIV was collected by survey interview. Saliva was obtained from all consenting respondents to assess actual HIV status. Of 2299 survey respondents who assessed their likelihood of being infected with HIV at the time of the survey, 71% were accurate. Most incorrect assessments (88%) were due to respondents overestimating (rather than underestimating) their likelihood of being infected with HIV. Women were less likely than men to correctly assess their HIV status. The two most important predictors of false-positive responses were marital status and self-reported health. Self-reports of HIV infection were generally valid. Most invalid self-reports were due to overestimating the risk of having HIV. The implications of this finding are highlighted, as they pertain to the design of HIV prevention interventions and the expansion of HIV counselling, testing and treatment programmes in developing countries.
Davies, K; Bulsara, M; Ramelet, A S; Monteroso, L
2018-01-18
To establish criterion-related construct validity and test-retest reliability for the Endotracheal Suction Assessment Tool© (ESAT©). Endotracheal tube suction performed in children can significantly affect clinical stability. Previously identified clinical indicators for endotracheal tube suction were used as criteria when designing the ESAT©. Content validity was reported previously. The final stages of psychometric testing are presented. Observational testing was used to measure construct validity and determine whether the ESAT© could guide 'inexperienced' paediatric intensive care nurses' decision-making regarding endotracheal tube suction. Test-retest reliability of the ESAT© was performed at two time points. The researchers and paediatric intensive care nurse 'experts' developed 10 hypothetical clinical scenarios with predetermined endotracheal tube suction outcomes. 'Experienced' (n=12) and 'inexperienced' (n=14) paediatric intensive care nurses were presented with the scenarios and the ESAT© guiding decision-making about whether to perform endotracheal tube suction for each scenario. Outcomes were compared with those predetermined by the 'experts' (n=9). Test-retest reliability of the ESAT© was measured at two consecutive time points (4 weeks apart) with 'experienced' and 'inexperienced' PIC nurses using the same scenarios and tool to guide decision-making. No differences were observed between endotracheal tube suction decisions made by 'experts' (n=9), 'inexperienced' (n=14) and 'experienced' (n=12) nurses confirming the tool's construct validity. No differences were observed between groups for endotracheal tube suction decisions at T1 and T2. Criterion-related construct validity and test-retest reliability of the ESAT© were demonstrated. Further testing is recommended to confirm reliability in the clinical setting with the 'inexperienced' nurse to guide decision-making related to endotracheal tube suction. This article is protected by copyright
Barrat, Emmanuel; Aubineau, Nicolas; Maillot, Matthieu; Derbord, Elodie; Barthes, Pauline; Lescuyer, Jean-François; Boisseau, Nathalie; Peltier, Sébastien L
2012-01-01
A 50-item self-administered food frequency questionnaire (FFQ) was developed for French adults, to assess the intake of energy, 10 macronutrients, 11 vitamins, and 11 minerals, and to be used in the context of a medical consultation. To assess the repeatability and relative validity of this FFQ compared to a 7-day diet record (7-DR). A total of 54 and 100 French adults were included in the repeatability and validation studies, respectively. Repeatability was assessed using two FFQs, the second carried out 3 weeks after the first. In the validation study, subjects first completed the FFQ, then the 7-DR the following week. Energy and nutrient intakes were compared using Pearson correlation. The degree of misclassification by the FFQ, compared to the 7-DR, was calculated by a contingency table of quintiles. Bland-Altman plots assessed the correlation between FFQ and 7-DR across the intake range. Repeatability for intake, explored by Pearson correlation, was 0.62-0.90 (median: 0.81). Relative validity, as determined by Pearson correlation for the nutrient intake derived from the FFQ and 7-DR, was 0.36-0.80 (0.64). The FFQ tended to report higher fiber and micronutrient intake than 7-DR. Misclassification into opposite quintiles ranged 0-6% (1%), whereas classification into same or adjacent quintiles ranged 59-83% (74%). Bland-Altman plots showed good agreement for most nutrients across the range of intake. This new FFQ showed a high repeatability and good relative validity, and thanks to its short length, should be a useful tool for rapidly evaluating the nutrient intake of French adults.
Directory of Open Access Journals (Sweden)
Emmanuel Barrat
2012-10-01
Full Text Available Background: A 50-item self-administered food frequency questionnaire (FFQ was developed for French adults, to assess the intake of energy, 10 macronutrients, 11 vitamins, and 11 minerals, and to be used in the context of a medical consultation. Objective: To assess the repeatability and relative validity of this FFQ compared to a 7-day diet record (7-DR. Design: A total of 54 and 100 French adults were included in the repeatability and validation studies, respectively. Repeatability was assessed using two FFQs, the second carried out 3 weeks after the first. In the validation study, subjects first completed the FFQ, then the 7-DR the following week. Energy and nutrient intakes were compared using Pearson correlation. The degree of misclassification by the FFQ, compared to the 7-DR, was calculated by a contingency table of quintiles. Bland–Altman plots assessed the correlation between FFQ and 7-DR across the intake range. Results: Repeatability for intake, explored by Pearson correlation, was 0.62–0.90 (median: 0.81. Relative validity, as determined by Pearson correlation for the nutrient intake derived from the FFQ and 7-DR, was 0.36–0.80 (0.64. The FFQ tended to report higher fiber and micronutrient intake than 7-DR. Misclassification into opposite quintiles ranged 0–6% (1%, whereas classification into same or adjacent quintiles ranged 59–83% (74%. Bland–Altman plots showed good agreement for most nutrients across the range of intake. Conclusion: This new FFQ showed a high repeatability and good relative validity, and thanks to its short length, should be a useful tool for rapidly evaluating the nutrient intake of French adults.
Sereda, Yuliia; Dembitskyi, Serhii
2016-08-26
The Symptom Checklist-90-Revised (SCL-90-R) is a widely used symptomatic distress questionnaire. A translated version of the SCL-90-R has been applied in Ukrainian general population surveys several times but has not yet been validated in this country. The SCL-90-R and its short versions (BSI-53, SCL-27, BSI-18, SCL-14 and SCL-9-K) were investigated in order to comparatively assess their properties and applications in Ukraine. Secondary analysis of three nationally representative cross-sectional surveys (1997, 1999 and 2014) using SCL-90-R was applied. Two thousand sixty nine respondents participated in 2014; the sample size for the 1997 and 1999 surveys was 1810 respondents per wave. Statistical data analysis is based on calculating internal consistencies with Cronbach's Alpha, confirmatory factor analysis, nonparametric correlations and effect sizes for the equivalence of the full and short versions. The scales of SCL-90-R and its shortened versions showed equally high internal consistencies. With regard to factorial validity, 2014 data confirmed the dimensional structure of all versions. Unsatisfactory results were found in 1997 and 1999 for SCL-90-R and in 1997 for SCL-27, based on the Chi-square criterion (χ2/degrees of freedom > 5), though other indexes suggested satisfactory model fit (RMSEA 0.95). Analysis of the equivalence of shortened and full versions of the SCL-90-R has shown the presence of small effect sizes. BSI-18 and SCL-9-K are recommended for use in general population surveys as more economical versions of SCL-90-R. Both versions revealed satisfactory validity in 1997, 1999 and 2014.
José-Manuel de Haro; Juan-Luis Castejón
2014-01-01
Although the study of factors affecting career success has shown connections between biographical and other aspects related to ability, knowledge and personality, few studies have examined the relationship be-tween emotional intelligence and professional success at the initial career stage. When these studies were carried out, the results showed significant relationships between the dimensions of emotional intelligence (emotional self-awareness, self-regulation, social awareness or social ski...
Development and validation of a scale to measure disease-related symptoms of kidney cancer.
Cella, David; Yount, Susan; Brucker, Penny S; Du, Hongyan; Bukowski, Ronald; Vogelzang, Nicholas; Bro, William P
2007-01-01
Using patient and expert provider input, we previously developed a 15-item index of the most important symptoms and concerns of people being treated for advanced kidney cancer, the Functional Assessment of Cancer Therapy - Kidney Symptom Index (FKSI). These 15 concerns are a mixture of disease-related symptoms and treatment-related side effects. As a result, it may be difficult to assign an informative label to the score defined as the summation of these 15 most important concerns. Because one of the primary goals of treating advanced kidney cancer is the relief of disease-related symptoms, we set out to differentiate from the list of 15 symptoms those that are predominantly attributable to kidney cancer itself rather than its treatment, and to evaluate this abbreviated FKSI - Disease-Related Symptoms (FKSI-DRS). Survey results from 18 experienced clinical experts were summarized to separate DRS from other concerns more arguably attributable to treatment side effects. This nine-item FKSI-DRS was then validated on a sample of 141 people with kidney cancer. The FKSI-DRS is reliable (internal consistency range = 0.75-0.78; test-retest reliability intraclass correlation = 0.85), and valid, separating groups by performance status and the patient's own global rating of change. The likely minimally important difference in the FKSI-DRS is in the range of 2-3 points. The FKSI-DRS is a reliable, valid, and responsive brief index of the most important symptoms associated with advanced kidney cancer.
Directory of Open Access Journals (Sweden)
Magis Andrew T
2012-09-01
Full Text Available Abstract Background Relative expression algorithms such as the top-scoring pair (TSP and the top-scoring triplet (TST have several strengths that distinguish them from other classification methods, including resistance to overfitting, invariance to most data normalization methods, and biological interpretability. The top-scoring ‘N’ (TSN algorithm is a generalized form of other relative expression algorithms which uses generic permutations and a dynamic classifier size to control both the permutation and combination space available for classification. Results TSN was tested on nine cancer datasets, showing statistically significant differences in classification accuracy between different classifier sizes (choices of N. TSN also performed competitively against a wide variety of different classification methods, including artificial neural networks, classification trees, discriminant analysis, k-Nearest neighbor, naïve Bayes, and support vector machines, when tested on the Microarray Quality Control II datasets. Furthermore, TSN exhibits low levels of overfitting on training data compared to other methods, giving confidence that results obtained during cross validation will be more generally applicable to external validation sets. Conclusions TSN preserves the strengths of other relative expression algorithms while allowing a much larger permutation and combination space to be explored, potentially improving classification accuracies when fewer numbers of measured features are available.
Aggressive Attitudes in Middle Schools: A Factor Structure and Criterion-Related Validity Study.
Huang, Francis L; Cornell, Dewey G; Konold, Timothy R
2015-08-01
Student attitudes toward aggression have been linked to individual aggressive behavior, but the relationship between school-wide normative beliefs about aggression and aggressive behavior poses some important measurement challenges that have not been adequately examined. The current study investigated the factor structure, measurement invariance, and criterion-related validity of a six-item Aggressive Attitudes scale using a large sample of seventh- and eighth-grade students (n = 39,364) from 423 schools. Analytic procedures accounted for the frequently ignored modeling problems of clustered and ordinal data to provide more reliable and accurate model estimates and standard errors. The resulting second-order factor structure of the Aggressive Attitudes scale demonstrated measurement invariance across gender, grade, and race/ethnicity groups. Criterion-related validity was supported with eight student- and school-level indices of aggressive behavior. © The Author(s) 2014.
Walter, Fiona M; Prevost, A Toby; Vasconcelos, Joana; Hall, Per N; Burrows, Nigel P; Morris, Helen C; Kinmonth, Ann Louise; Emery, Jon D
2013-05-01
GPs need to recognise significant pigmented skin lesions, given rising UK incidence rates for malignant melanoma. The 7-point checklist (7PCL) has been recommended by NICE (2005) for routine use in UK general practice to identify clinically significant lesions which require urgent referral. To validate the Original and Weighted versions of the 7PCL in the primary care setting. Diagnostic validation study, using data from a SIAscopic diagnostic aid randomised controlled trial in eastern England. Adults presenting in general practice with a pigmented skin lesion that could not be immediately diagnosed as benign were recruited into the trial. Reference standard diagnoses were histology or dermatology expert opinion; 7PCL scores were calculated blinded to the reference diagnosis. A case was defined as a clinically significant lesion for primary care referral to secondary care (total 1436 lesions: 225 cases, 1211 controls); or melanoma (36). For diagnosing clinically significant lesions there was a difference between the performance of the Original and Weighted 7PCLs (respectively, area under curve: 0.66, 0.69, difference = 0.03, Plesions in primary care: sensitivity 73.3%, specificity 57.1%, positive predictive value 24.1%, negative predictive value 92.0%, while maintaining high sensitivity of 91.7% and moderate specificity of 53.4% for melanoma. The Original and Weighted 7PCLs both performed well in a primary care setting to identify clinically significant lesions as well as melanoma. The Weighted 7PCL, with a revised cut-off score of 4 from 3, performs slightly better and could be applied in general practice to support the recognition of clinically significant lesions and therefore the early identification of melanoma.
Directory of Open Access Journals (Sweden)
Jonas J. de Paula
2014-05-01
Full Text Available Objective: To propose and evaluate the psychometric properties of a multidimensional measure of activities of daily living (ADLs based on the Katz and Lawton indices for Alzheimer's disease (AD and mild cognitive impairment (MCI. Methods: In this study, 85 patients with MCI and 93 with AD, stratified by age (≤ 74 years, > 74 years, completed the Mini Mental State Examination (MMSE and the Geriatric Depression Scale, and their caregivers completed scales for ADLs. Construct validity (factor analysis, reliability (internal consistency, and criterion-related validity (receiver operating characteristic analysis and logistic regression were assessed. Results: Three factors of ADL (self-care, domestic activities, and complex activities were identified and used for item reorganization and for the creation of a new inventory, called the General Activities of Daily Living Scale (GADL. The components showed good internal consistency (> 0.800 and moderate (younger participants or high (older participants accuracy for the distinction between MCI and AD. An additive effect was found between the GADL complex ADLs and global ADLs with the MMSE for the correct classification of younger patients. Conclusion: The GADL showed evidence of validity and reliability for the Brazilian elderly population. It may also play an important role in the differential diagnosis of MCI and AD.
Development and psychometric validation of the Diabetes Therapy-Related QOL (DTR-QOL) questionnaire.
Ishii, Hitoshi
2012-01-01
We developed and evaluated the psychometric properties of the Diabetes Therapy-Related QOL (DTR-QOL) as a disease-specific, self-administered questionnaire to assess the influence of diabetes treatment on patient QOL, regardless of treatment method. This new questionnaire was developed and validated in a standardized manner: Item development, pilot-testing and psychometric validation. A survey was conducted using the provisional version of the questionnaire, and reliability and validity were evaluated with psychometric testing. The provisional version of the questionnaire was generated with 29 items through literature review and pilot testing. For psychometric assessment, analyses were performed on the responses of 284 adult Japanese patients with diabetes. Factor analysis by the principal factor method with promax rotation revealed 4 factors; "burden on social activities and daily activities" (13 items), "anxiety and dissatisfaction with treatment" (8 items), "hypoglycemia" (4 items), and "satisfaction with treatment" (4 items). For reliability, the intraclass correlation was 0.92, and Cronbach's alpha coefficient was 0.94, indicating adequate test-retest reliability and internal consistency. For known-group validity, there were significant differences in scores for following variables: age, diabetes type, HbA1c, treatment method, glycemic control, hypoglycemia, nocturnal hypoglycemia, concern about weight gain, health status (patient assessment), and degree of communication with physician. The DTR-QOL, with good reliability and validity, can assess the influence of diabetes treatment on patient QOL. The DTR-QOL can be used regardless of treatment method that patients receive, and this characteristic enables to detect a difference on patients QOL between treatment methods before and after a switch of treatment. Limitations of this study include representativeness of the patient sample. The relatively small number of patients with type 1 diabetes should be noted
Reliability and validity of brief psychosocial measures related to dietary behaviors
Directory of Open Access Journals (Sweden)
Calfas Karen J
2010-07-01
Full Text Available Abstract Background Measures of psychosocial constructs are required to assess dietary interventions. This study evaluated brief psychosocial scales related to 4 dietary behaviors (consumption of fat, fiber/whole grains, fruits, and vegetables. Methods Two studies were conducted. Study 1 assessed two-week reliability of the psychosocial measures with a sample of 49 college students. Study 2 assessed convergent and discriminant validity of the psychosocial measures with dietary nutrient estimates from a Food Frequency Questionnaire on 441 men and 401 women enrolled in an Internet-based weight loss intervention study. Results Study 1 test-retest reliability ICCs were strong and ranged from .63 to .79. In study 2, dietary fat cons, fiber/whole grain cons and self-efficacy, fruit and vegetable cons and self-efficacy, and healthy eating social support, environmental factors, enjoyment, and change strategies demonstrated adequate correlations with the corresponding dietary nutrient estimates. Conclusions Brief psychosocial measures related to dietary behaviors demonstrated adequate reliability and in most cases validity. The strongest and most consistent scales related to dietary behaviors were healthy eating change strategies and enjoyment. Consistent convergent validity was also found for the cons of change scales. These measures can be used in intervention studies to evaluate psychosocial mediators of dietary change in overweight and obese individuals.
Smalley, L. L.
1983-01-01
The proper framework for testing Rastall's theory and its generalizations is in the case of non-negligible (i.e. discernible) gravitational effects such as gravity gradients. These theories have conserved integral four-momentum and angular momentum. The Nordtvedt effect then provides limits on the parameters which arise as the result of the non-zero divergence of the energy-momentum tensor.
Sackett, Paul R; Shewach, Oren R; Keiser, Heidi N
2017-10-01
Separate meta-analyses of the cognitive ability and assessment center (AC) literatures report higher criterion-related validity for cognitive ability tests in predicting job performance. We instead focus on 17 samples in which both AC and ability scores are obtained for the same examinees and used to predict the same criterion. Thus, we control for differences in job type and in criteria that may have affected prior conclusions. In contrast to Schmidt and Hunter's (1998) meta-analysis, reporting mean validity of .51 for ability and .37 for ACs, we found using random-effects models mean validity of .22 for ability and .44 for ACs using comparable corrections for range restriction and measurement error in the criterion. We posit that 2 factors contribute to the differences in findings: (a) ACs being used on populations already restricted on cognitive ability and (b) the use of less cognitively loaded criteria in AC validation research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Basen-Engquist, K; Mâsse, L C; Coyle, K; Kirby, D; Parcel, G S; Banspach, S; Nodora, J
1999-02-01
We examined the content, construct and concurrent validity of scales to assess beliefs and self-efficacy related to adolescents' sexual risk behavior. We addressed content validity in the scale development process by drawing on literature and theory, and by pre-testing items with focus groups. We used confirmatory factor analysis of two models, an intercourse involvement model and a condom use model, to assess construct validity. The final intercourse involvement model included three scales: norms about sexual intercourse, attitudes about sexual intercourse and self-efficacy in refusing sex. The final condom use model included five scales: norms about condoms, attitudes about condom use, self-efficacy in communicating about condoms, self-efficacy in buying/using condoms and barriers to condom use. After two alterations to the models, the chi 2 and other indices indicated that the data fit the models well. Supporting the concurrent validity of the scales, high school students who had never had sexual intercourse had more negative attitudes toward sexual intercourse among teenagers, perceived norms toward sexual intercourse among teenagers to be more negative and expressed greater self-efficacy in refusing sex than did those who had experienced sexual intercourse. Consistent condom users had more positive attitudes and norms about condoms, had higher self-efficacy in communicating about and buying/using condoms, and perceived fewer barriers to condom purchase and use than did inconsistent condom users.
Energy Technology Data Exchange (ETDEWEB)
Istomin, V. A.; Kustova, E. V.; Mekhonoshina, M. A. [Department of Mathematics and Mechanics, Saint Petersburg State University, 198504 Universitetskiy pr., 28, Saint Petersburg (Russian Federation)
2014-12-09
In the present work we evaluate the accuracy of the Eucken formula and Stokes’ viscosity relation in high temperature non-equilibrium air species with electronic excitation. The thermal conductivity coefficient calculated using the exact kinetic theory methods is compared with that obtained applying approximate formulas in the temperature range 200–20000 K. A modification of the Eucken formula providing a good agreement with exact calculations is proposed. It is shown that the Stokes viscosity relation is not valid in electronically excited monoatomic gases at temperatures higher than 2000 K.
Morris, Roisin; Matthews, Anne; Scott, Anne P
2014-04-01
Internationally, nursing professionals are coming under increasing pressure to highlight the contribution they make to health care and patient outcomes. Despite this, difficulties exist in the provision of quality information aimed at describing nursing work in sufficient detail. The Irish Minimum Data Set for General Nursing is a new nursing data collection system aimed at highlighting the contribution of nursing to patient care. The objectives of this study were to investigate the construct validity and internal reliability of the Irish Nursing Minimum Data Set for General Nursing and to assess its usefulness in measuring the mediating effects of nursing interventions on patient well-being for a group of short stay medical and surgical patients. This was a quantitative study using a repeated measures design. Participants sampled came from both general surgery and general medicine wards in 6 hospitals throughout the Republic of Ireland. Nurses took on the role of data collectors. Nurses participating in the study were qualified, registered nurses engaged in direct patient care. Because the unit of analysis for this study was the patient day, patient numbers were considered in estimations of sample size requirements. A total of 337 usable Nursing Minimum Data Set booklets were collected. The construct validity of the tool was established using exploratory factor analysis with a Promax rotation and Maximum Likelihood extraction. Internal reliability was established using the Cronbach's Alpha coefficient. Path analysis was used to assess the mediating effects of nursing interventions on patient well-being. The results of the exploratory factor analysis and path analysis met the criteria for an appropriate model fit. All Cronbach Alpha scores were above .7. The overall findings of the study inferred that the Irish Nursing Minimum Data for General Nursing possessed construct validity and internal reliability. The study results also inferred the potential of the tool in
Energy Technology Data Exchange (ETDEWEB)
Chen Haijin [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China); Jiang-Su Provincial Key Lab of ASIC Design, Nantong University, Nantong 226019 (China)], E-mail: chen.hj@ntu.edu.cn; Lu Shengli; Shi Longxing [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China)
2009-03-15
A general-purpose application specific integrated circuit (ASIC) chip for the control of switched reluctance machines (SRMs) was designed and validated to fill the gap between the microcontroller capability and the controller requirements of high performance switched reluctance drive (SRD) systems. It can be used for the control of SRM running either in low speed or in high-speed, i.e., either in chopped current control (CCC) mode or in angular position control (APC) mode. Main functions of the chip include filtering and cycle calculation of rotor angular position signals, commutation logic according to rotor cycle and turn-on/turn-off angles ({theta}{sub on}/{theta}{sub off}), controllable pulse width modulation (PWM) waveforms generation, chopping control with adjustable delay time, and commutation control with adjustable delay time. All the control parameters of the chip are set online by the microcontroller through a serial peripheral interface (SPI). The chip has been designed with the standard cell based design methodology, and implemented in the central semiconductor manufacturing corporation (CSMC) 0.5 {mu}m complementary metal-oxide-semiconductor (CMOS) process technology. After a successful automatic test equipment (ATE) test using the Nextest's Maverick test system, the chip was further validated through an experimental three-phase 6/2-pole SRD system. Both the ATE test and experimental validation results show that the chip can meet the control requirements of high performance SRD systems, and simplify the controller construction. For a resolution of 0.36 deg. (electrical degree), the chip's maximum processable frequency of the rotor angular position signals is 10 kHz, which is 300,000 rev/min when a three-phase 6/2-pole SRM is concerned.
Energy Technology Data Exchange (ETDEWEB)
Chen, Hai-Jin [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China)]|[Jiang-Su Provincial Key Lab of ASIC Design, Nantong University, Nantong 226019 (China); Lu, Sheng-Li; Shi, Long-Xing [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China)
2009-03-15
A general-purpose application specific integrated circuit (ASIC) chip for the control of switched reluctance machines (SRMs) was designed and validated to fill the gap between the microcontroller capability and the controller requirements of high performance switched reluctance drive (SRD) systems. It can be used for the control of SRM running either in low speed or in high-speed, i.e., either in chopped current control (CCC) mode or in angular position control (APC) mode. Main functions of the chip include filtering and cycle calculation of rotor angular position signals, commutation logic according to rotor cycle and turn-on/turn-off angles ({theta}{sub on}/{theta}{sub off}), controllable pulse width modulation (PWM) waveforms generation, chopping control with adjustable delay time, and commutation control with adjustable delay time. All the control parameters of the chip are set online by the microcontroller through a serial peripheral interface (SPI). The chip has been designed with the standard cell based design methodology, and implemented in the central semiconductor manufacturing corporation (CSMC) 0.5 {mu}m complementary metal-oxide-semiconductor (CMOS) process technology. After a successful automatic test equipment (ATE) test using the Nextest's Maverick test system, the chip was further validated through an experimental three-phase 6/2-pole SRD system. Both the ATE test and experimental validation results show that the chip can meet the control requirements of high performance SRD systems, and simplify the controller construction. For a resolution of 0.36 (electrical degree), the chip's maximum processable frequency of the rotor angular position signals is 10 kHz, which is 300,000 rev/min when a three-phase 6/2-pole SRM is concerned. (author)
Directory of Open Access Journals (Sweden)
Xianghua Xu
2018-01-01
Full Text Available Objective: To translate the English work-related acceptance and action questionnaire (WAAQ, make cross-cultural adaptations, and examine its psychometric properties when used by Chinese oncology nurses. Methods: After translation, the psychometric properties of the Chinese WAAQ were analyzed among 417 nurses, and content validity was determined by six experts. Results: Item-level content validity index (CVI values were between 0.83 and 1.00; scale-level CVI/universal agreement (S-CVI/UA and S-CVI/average were 0.86 and 0.98, respectively, which implicated a good content validity. The correlation of the Chinese WAAQ with AAQ-II (rs= −0.247, P < 0.001 suggested criterion validity, and those with General Health Questionnaire-12 (−0.250, <0.001 and general self-efficacy scale (0.491, <0.001 and Utrecht work engagement scale (UWES (0.439, <0.001 suggested convergent validity. Exploratory factor analysis identified a seven-item, one-factor structure of WAAQ. The Chinese version of WAAQ had high internal consistency (Cronbach's α = 0.920, with an item-total correlation coefficient of 0.702–0.828 (P < 0.05, split-half reliability of 0.933, and test-retest reliability of 0.772. Conclusions: The Chinese WAAQ is a reliable and valid tool for assessing psychological flexibility in Chinese oncology nurses.
Burcu, Mehmet; Alexander, G Caleb; Ng, Xinyi; Harrington, Donna
2015-02-01
Millions of Americans are burdened by out-of-pocket prescription costs. Although many survey measures have been developed to assess this burden, the construct validity and the factor structure of these instruments have not been rigorously assessed. To characterize the factor structure and the construct validity of items assessing cost-related medication burden. We applied exploratory factor and confirmatory factor analyses to the 2009 Medicare Current Beneficiary Survey, focusing on 10 items assessing cost-related mediation burden among a nationally representative sample of community-dwelling Medicare beneficiaries. The fit of competing models was compared using several indices. The study population (N=8777) was predominantly aged over 65 years (83.3%), female (54.4%), and white (84.3%). Two distinct factors were present for the medication cost-reduction strategies: (1) cost-related medication nonadherence and (2) drug-shopping behaviors, not directly impacting medication compliance. The two factors were moderately correlated (r=0.55), highlighting the presence of a 2 distinct but related constructs for cost-related medication burden. An item assessing the use of mail or internet pharmacies did not load well on either factor and may not necessarily measure medication-related cost burden. An item assessing reduced spending on basic needs loaded strongly on the same factor with the cost-related medication nonadherence items, suggesting they together may represent extreme compensatory behaviors that may adversely affect health outcomes. Two distinct constructs were derived from these items examining cost-related medication burden. Although cost-related medication burden is often associated with nonadherence, drug-shopping behaviors that do not directly impact adherence are also important measure of this burden.
Hernández Ruipérez, Tomás; Leal Costa, César; Adánez Martínez, María de Gracia; García Pérez, Bartolomé; Nova López, Daniel; Díaz Agea, José Luis
2015-10-01
To determine whether the Emergency Severity Index (ESI) is valid for triage according to evidence based on classifying real patients in a general referral hospital's emergency department. Observational, cross-sectional descriptive study carried out in the emergency department of Hospital Clínico Universitario Virgen de la Arrixaca in Murcia. Thirty-two nurses used the ESI algorithm to triage 410 patients as they arrived seeking care. The results were compared to a gold standard (a triage expert's opinion, which was later confirmed by an expert committee after discussion, if necessary, of cases for which opinions were not unanimous). We calculated sensitivity, specificity, under- and over-triage rates, as well as descriptive statistics about resource assignment, exitus, patients who left without being seen, destination on discharge, and times. ESI was highly correlated with resources (ρ = -0.717, P < .01) and moderately correlated with destination on discharge (ρ = -0.437, P < .01). Regarding time spent in the department, we found that patients assigned ESI levels 1 and 2 had significantly longer stays, and those assigned ESI levels 4 and 5 had significantly shorter stays (p < 0,001). Interobserver agreement was good or very good, indicating that this triage tool is reliable. This pilot of the ESI triage algorithm in the emergency department of a referral hospital found evidence supporting the system's validity.
Scherrer, Vsevolod; Roberts, Richard; Preckel, Franzis
2016-01-01
Meta-analyses suggest that morning-oriented students obtain better school grades than evening-oriented students. This finding has generally been found for students in high school using self-report data for the assessment of circadian preference. Two studies (N = 2718/192) investigated whether these findings generalize across samples (i.e. elementary school-aged students) and methods (i.e. parent reports). These studies also explored whether the relation between circadian preference and school achievement could be explained within an expectancy-value framework. To this end, the Lark-Owl Chronotype Indicator (LOCI) was modified to obtain parents' evaluations of their children's circadian preference, while students completed a battery of assessments designed to explore the test-criterion evidence. Structural equation modeling and correlational analyses revealed: (1) morning and evening orientation were two separable factors of children's circadian preference; (2) correlations with behavioral (e.g. sleep and eating times) and psychological (e.g. cognitive ability) data supported the test-criterion validity of both factors; (3) morning orientation was positively related to school achievement and (4) consistent with an expectancy-value framework this relation was mediated by children's academic self-concept (ASC). These findings have important research and policy implications for considering circadian preference in the schooling of elementary students.
Yu, Sheng-Tsung; Chang, Hsing-Yi; Yao, Kai-Ping; Lin, Yu-Hsuan; Hurng, Baai-Shyun
2015-10-01
The aim of this study was to examine the validity of the EuroQOL five dimensions questionnaire (EQ-5D) using a nationally representative data from the National Health Interview Survey (NHIS) through comparison with short-form 36 (SF-36). Data for this study came from the 2009 NHIS in Taiwan. The study sample was the 4007 participants aged 20-64 years who completed the survey. We used SUDAAN 10.0 (SAS-Callable) to carry out weighed estimation and statistical inference. The EQ index was estimated using norm values from a Taiwanese study as well as from Japan and the United Kingdom (UK). The SF-36 score was standardized using American norm values. In terms of concurrent validity, the EQ-5D met the five hypotheses. The results did not fulfill hypothesis that women would have lower visual analogue scale (EQ-VAS) scores. In terms of discriminant validity, the EQ-5D fulfilled two hypotheses. Our results approached but did not fulfill hypothesis that there would be a weak association between the physical and psychological dimensions of the EQ-5D and the mental component summary score of the SF-36. Results were comparable regardless of whether the Japanese or UK norm value sets were used. We were able to fulfill many, not all of our validity hypotheses regardless of whether the established Japanese or UK norm value sets or the Taiwanese norm values were used. The EQ-5D is an effective and simple instrument for assessing health-related quality of life of general population in Taiwan.
General movements in the perinatal period and its relation to echogenicity changes in the brain
Rosier-van Dunne, F.M.F.; Wezel-Meijler, G.; Bakker, M.P.; de Groot, L.; Odendaal, H.J.; de Vries, J.I.P.
2010-01-01
Background: In preterm born infants abnormal general movements (GMs) generally normalize before three months post term, but may persist when perinatal brain injury is present. Aims: To assess the continuity of GM quality from fetal to early neonatal period and its relation to brain echogenicity
Racism-Related Stress, General Life Stress, and Psychological Functioning among Black American Women
Pieterse, Alex L.; Carter, Robert T.; Ray, Kilynda V.
2013-01-01
The relationship between general life stress, perceived racism, and psychological functioning was explored in a sample of 118 Black American women. Findings indicate that racism-related stress was not a significant predictor of psychological functioning when controlling for general life stress. Perceived racism was positively associated with…
Muschalla, Beate; Glatz, Johannes; Linden, Michael
2014-01-01
Absence of an adequate reason for anxiety is a criterion for pathological anxiety. However, the presence of danger or fear-provoking stimuli may even be a risk factor for anxiety and does not exclude that there is additionally pathological anxiety too. The question is, to what degree can heart-related anxiety be explained by the severity of illness or trait anxiety? Two hundred and nine patients (37.8% women) from a cardiology inpatient unit completed the Heart-Anxiety-Questionnaire, Progression-Anxiety-Questionnaire, Job-Anxiety-Scale and the State-Trait-Anxiety-Inventory. The severity of cardiac illness was rated by the treating cardiologists using the Multidimensional Severity of Morbidity Rating. Time absent from work due to sickness was assessed as an indicator for illness-related impairment. Heart anxiety was significantly related to progression anxiety and, to a lesser extent, trait anxiety and indicators of subjective symptoms of somatic illness. No association was found with medical ratings for prognosis, multimorbidity, or reduction in life expectancy. Heart-related anxiety is a symptom of an anxiety disorder. Although partially dependent on subjective suffering, it cannot be explained by the severity of medical illness. Treatment of health-related anxieties should focus on how to cope with subjective symptoms of illness.
Validation of anti-aging drugs by treating age-related diseases.
Blagosklonny, Mikhail V
2009-03-28
Humans die from age-related diseases, which are deadly manifestations of the aging process. In order to extend life span, an anti-aging drug must delay age-related diseases. All together age-related diseases are the best biomarker of aging. Once a drug is used for treatment of any one chronic disease, its effect against other diseases (atherosclerosis, cancer, prostate enlargement, osteoporosis, insulin resistance, Alzheimer's and Parkinson's diseases, age-related macular degeneration) may be evaluated in the same group of patients. If the group is large, then the anti-aging effect could be validated in a couple of years. Startlingly, retrospective analysis of clinical and preclinical data reveals four potential anti-aging modalities.
Propagators of Generalized Schrödinger Equations Related by First-order Supersymmetry
Directory of Open Access Journals (Sweden)
A. Schulze-Halberg
2011-01-01
Full Text Available We construct an explicit relation between propagators of generalized Schrödinger equations that are linked by a first-order supersymmetric transformation. Our findings extend and complement recent results on the conventional case [1].
Gravitational redshift of galaxies in clusters as predicted by general relativity.
Wojtak, Radosław; Hansen, Steen H; Hjorth, Jens
2011-09-28
The theoretical framework of cosmology is mainly defined by gravity, of which general relativity is the current model. Recent tests of general relativity within the Lambda Cold Dark Matter (ΛCDM) model have found a concordance between predictions and the observations of the growth rate and clustering of the cosmic web. General relativity has not hitherto been tested on cosmological scales independently of the assumptions of the ΛCDM model. Here we report an observation of the gravitational redshift of light coming from galaxies in clusters at the 99 per cent confidence level, based on archival data. Our measurement agrees with the predictions of general relativity and its modification created to explain cosmic acceleration without the need for dark energy (the f(R) theory), but is inconsistent with alternative models designed to avoid the presence of dark matter. © 2011 Macmillan Publishers Limited. All rights reserved
Fisher Sand & Gravel New Mexico, Inc. General Air Quality Permit: Related Documents
Documents related to the Fisher Sand & Gravel – New Mexico, Inc., Grey Mesa Gravel Pit General Air Quality Permit for New or Modified Minor Source Stone Quarrying, Crushing, and Screening Facilities in Indian Country.
Thombs, Brett D; Ziegelstein, Roy C; Beck, Christine A; Pilote, Louise
2008-08-01
Many studies have linked symptoms of depression after an acute myocardial infarction (AMI) to negative health outcomes, including mortality. It has been suggested, however, that this link may be due to biased measurement of depressive symptoms in post-AMI patients related to confounding with somatic symptoms related to AMI. The objective of this study was to validate a factor model for the Beck Depression Inventory-II (BDI-II) that would allow for modeling of depressive symptoms after explicitly removing bias related to somatic symptom overlap. A total of 477 hospitalized post-AMI patients from 10 cardiac care units were administered the BDI-II. Confirmatory factor analysis models for ordinal data were conducted with MPLUS to test the fit of a model with a single General Depression factor (all 21 BDI-II items) and uncorrelated Somatic (5 items) and Cognitive (8 items) factors (G-S-C model) compared to standard correlated two-factor models. The G-S-C model fit as well or better than previously published correlated two-factor models. Seventy-three percent of variance in BDI-II scores is accounted for by the General Depression factor, whereas 11% and 13% respectively are accounted for by uncorrelated Somatic and Cognitive factors. The G-S-C model is a novel approach to understanding the measurement structure of the BDI-II, presents advantageous statistical and interpretive properties compared to standard correlated factor models, and provides a viable mechanism to test links between symptoms of depression, as measured by the General Depression factor, and health outcomes among patients with AMI after explicitly removing variance from somatic symptoms unrelated to the General Depression factor.
General and gay-related racism experienced by Latino gay men.
Ibañez, Gladys E; Van Oss Marin, Barbara; Flores, Stephen A; Millett, Gregorio; Diaz, Rafael M
2009-07-01
Latino gay men report experiences of racial discrimination within and outside the gay community. This study focused on correlates of racism within general and gay contexts. Racism was assessed in a probability sample of 911 Latino gay men recruited from 3 U.S. cities. Factor analysis of the 10-item scale produced 2 factors: (a) General Racism Experiences, and (b) Racism Experiences in Gay Contexts. The scale and each factor showed adequate reliability and validity. Latino gay men with darker skin, more Indian features, more time in the United States, and low self-esteem reported more racism in both general and gay contexts. The authors examine the psychometric properties of a measure that assesses interpersonal racism among Latinos, report correlates of racism within a gay context, and provide an assessment tool for understanding the role of racism in the lives of Latino gay men.
Classical tests of general relativity: Brane-world Sun from minimal geometric deformation
Casadio, R.; Ovalle, J.; da Rocha, Roldão
2015-05-01
We consider a solution of the effective four-dimensional brane-world equations, obtained from the general relativistic Schwarzschild metric via the principle of minimal geometric deformation, and investigate the corresponding signatures stemming from the possible existence of a warped extra-dimension. In particular, we derive bounds on an extra-dimensional parameter, closely related with the fundamental gravitational length, from the experimental results of the classical tests of general relativity in the Solar system.
Belo, J N; Bierma-Zeinstra, S M A; Terwee, C B; Heintjes, E M; Koes, B W
2008-12-01
The aim of the study was to determine the cross-sectional and longitudinal validity of a performance-based assessment of knee function, DynaPort KneeTest (DPKT), in first-time consulters with nontraumatic knee complaints in general practice. Patients consulting for nontraumatic knee pain in general practice aged >18 years were enrolled in the study. At baseline and 6-months follow-up knee function was assessed by questionnaires and the DPKT; a physical examination was also performed at baseline. Hypothesis testing assessed the cross-sectional and longitudinal validity of the DPKT. Eighty-seven patients were included for the DPKT, 86 were available for analysis. The studied population included 44 women (51.2%), the median age was 54 (range 18-81) years. At follow up, 77 patients (89.5%) were available for the DPKT. Only 3 out of 11 (27%) predetermined hypotheses concerning the cross-sectional and longitudinal validity were confirmed. Comparison of the general practice and secondary care population showed a major difference in baseline characteristics, DynaPort Knee Score, internal consistency, and hypotheses confirmation concerning the construct validity. The validity of the DPKT could not be demonstrated for first-time consulters with nontraumatic knee complaints in general practice. Measurement instruments developed and validated in secondary care are therefore not automatically also valid in primary care setting.
Reliability and criterion-related validity of a new repeated agility test.
Fessi, M S; Makni, E; Jemni, M; Elloumi, M; Chamari, K; Nabli, M A; Padulo, J; Moalla, W
2016-06-01
The study aimed to assess the reliability and the criterion-related validity of a new repeated sprint T-test (RSTT) that includes intense multidirectional intermittent efforts. The RSTT consisted of 7 maximal repeated executions of the agility T-test with 25 s of passive recovery rest in between. Forty-five team sports players performed two RSTTs separated by 3 days to assess the reliability of best time (BT) and total time (TT) of the RSTT. The intra-class correlation coefficient analysis revealed a high relative reliability between test and retest for BT and TT (>0.90). The standard error of measurement (related to the RSTT were 0.09 s and 0.58 s, respectively. To check the criterion-related validity of the RSTT, players performed a repeated linear sprint (RLS) and a repeated sprint with changes of direction (RSCD). Significant correlations between the BT and TT of the RLS, RSCD and RSTT were observed (pvalid measure of the intermittent repeated sprint agility performance. As this ability is required in all team sports, it is suggested that team sports coaches, fitness coaches and sports scientists consider this test in their training follow-up.
Mekhora, Keerin; Jalayondeja, Wattana; Jalayondeja, Chutima; Bhuanantanondh, Petcharatana; Dusadiisariyavong, Asadang; Upiriyasakul, Rujiret; Anuraktam, Khajornyod
2014-07-01
To develop an online, self-report questionnaire on computer work-related exposure (OSCWE) and to determine the internal consistency, face and content validity of the questionnaire. The online, self-report questionnaire was developed to determine the risk factors related to musculoskeletal disorders in computer users. It comprised five domains: personal, work-related, work environment, physical health and psychosocial factors. The questionnaire's content was validated by an occupational medical doctor and three physical therapy lecturers involved in ergonomic teaching. Twenty-five lay people examined the feasibility of computer-administered and the user-friendly language. The item correlation in each domain was analyzed by the internal consistency (Cronbach's alpha; alpha). The content of the questionnaire was considered congruent with the testing purposes. Eight hundred and thirty-five computer users at the PTT Exploration and Production Public Company Limited registered to the online self-report questionnaire. The internal consistency of the five domains was: personal (alpha = 0.58), work-related (alpha = 0.348), work environment (alpha = 0.72), physical health (alpha = 0.68) and psychosocial factor (alpha = 0.93). The findings suggested that the OSCWE had acceptable internal consistency for work environment and psychosocial factors. The OSCWE is available to use in population-based survey research among computer office workers.
Janssen, Michel
2012-08-01
In publications in 1914 and 1918, Einstein claimed that his new theory of gravity in some sense relativizes the rotation of a body with respect to the distant stars (a stripped-down version of Newton's rotating bucket experiment) and the acceleration of the traveler with respect to the stay-at-home in the twin paradox. What he showed was that phenomena seen as inertial effects in a space-time coordinate system in which the non-accelerating body is at rest can be seen as a combination of inertial and gravitational effects in a (suitably chosen) space-time coordinate system in which the accelerating body is at rest. Two different relativity principles play a role in these accounts: (a) the relativity of non-uniform motion, in the weak sense that the laws of physics are the same in the two space-time coordinate systems involved; (b) what Einstein in 1920 called the relativity of the gravitational field, the notion that there is a unified inertio-gravitational field that splits differently into inertial and gravitational components in different coordinate systems. I provide a detailed reconstruction of Einstein's rather sketchy accounts of the twins and the bucket and examine the role of these two relativity principles. I argue that we can hold on to (b) but that (a) is either false or trivial.
DEFF Research Database (Denmark)
Knudsen, Vibeke Kildegaard; Gille, Maj-Britt; Nielsen, Trine Holmgaard
2011-01-01
Objective: To determine the relative validity of the pre-coded food diary applied in the Danish National Survey of Dietary Habits and Physical Activity. Design: A cross-over study among seventy-two adults (aged 20 to 69 years) recording diet by means of a pre-coded food diary over 4 d and a 4 d...... weighed food record. Intakes of foods and drinks were estimated, and nutrient intakes were calculated. Means and medians of intake were compared, and crossclassification of individuals according to intake was performed. To assess agreement between the two methods, Pearson and Spearman’s correlation......, and intakes of fruit, coffee and tea were lower, in the weighed food record compared with the food diary. Intakes of nutrients were grossly the same in the two methods, except for protein, where a higher intake was recorded in the weighed record. In general, moderate agreement between the two methods...
Zlatarić, Dubravka Knezović; Celebić, Asja
2008-01-01
This study aimed to analyze factors related to patients' general satisfaction with removable partial dentures (RPDs), such as esthetics, retention, speech, chewing, and comfort. A total of 103 patients with Kennedy Class I RPDs (34 to 82 years old; mean age: 63; 35 men, 68 women) assessed their satisfaction with dentures. Stepwise multiple regression analysis was used to evaluate the relationship among the factors. Significant correlations were found between general satisfaction and each of the individual components (P < .05). The patients' assessment of esthetics explained almost 50% of general satisfaction in both arches (P < .05). Esthetics, chewing, and speech had significant effects on the patients' general satisfaction with dentures.
Shahidi, Saeid; Owen-Falkenberg, Alan; Gottschalksen, Bo
2017-06-01
The aim of this study was to validate a mean stump pressure (SP) of 40 mmHg as the cut off threshold for shunting during carotid endarterectomy (CEA). A prospective analysis of recently symptomatic carotid stenosis patients undergoing fast-track CEA under general anesthesia. An arbitrary cut-off threshold of 40 mmHg (mean) was defined as the indication for shunt insertion. With an SPcarotid artery (ICA) was found in our study P=0.05. Sixteen patients (14%) had SPcarotid arteries. Raising blood pressure intra-operatively by 10-20% reduced the incidence of shunt insertion to only three patients (80% reduction). Of the 120 CEAs, only 2.5% (95% CI 1-6%) of patients required shunt. There was no post-operative TIA or stroke in our study. Two patients (1.65%) suffered early TIA from ipsilateral ICA after discharge from the vascular unit. Using a mean SP of 40 mmHg as a threshold seems to be a safe, easy and cheap method for selective shunt insertion in fast track CEA under general anesthesia with a zero false-negative rate. Raising the systemic blood pressure by 10-20% during cross clamping increased SP above the threshold value 40 mmHg, thus avoiding shunt insertion in a number of patients.
Directory of Open Access Journals (Sweden)
Bieliński Henryk
2016-09-01
Full Text Available The current paper presents the experimental validation of the generalized model of the two-phase thermosyphon loop. The generalized model is based on mass, momentum, and energy balances in the evaporators, rising tube, condensers and the falling tube. The theoretical analysis and the experimental data have been obtained for a new designed variant. The variant refers to a thermosyphon loop with both minichannels and conventional tubes. The thermosyphon loop consists of an evaporator on the lower vertical section and a condenser on the upper vertical section. The one-dimensional homogeneous and separated two-phase flow models were used in calculations. The latest minichannel heat transfer correlations available in literature were applied. A numerical analysis of the volumetric flow rate in the steady-state has been done. The experiment was conducted on a specially designed test apparatus. Ultrapure water was used as a working fluid. The results show that the theoretical predictions are in good agreement with the measured volumetric flow rate at steady-state.
Bieliński, Henryk
2016-09-01
The current paper presents the experimental validation of the generalized model of the two-phase thermosyphon loop. The generalized model is based on mass, momentum, and energy balances in the evaporators, rising tube, condensers and the falling tube. The theoretical analysis and the experimental data have been obtained for a new designed variant. The variant refers to a thermosyphon loop with both minichannels and conventional tubes. The thermosyphon loop consists of an evaporator on the lower vertical section and a condenser on the upper vertical section. The one-dimensional homogeneous and separated two-phase flow models were used in calculations. The latest minichannel heat transfer correlations available in literature were applied. A numerical analysis of the volumetric flow rate in the steady-state has been done. The experiment was conducted on a specially designed test apparatus. Ultrapure water was used as a working fluid. The results show that the theoretical predictions are in good agreement with the measured volumetric flow rate at steady-state.
Heusser, Stephanie A; Howard, Rebecca J; Borghese, Cecilia M; Cullins, Madeline A; Broemstrup, Torben; Lee, Ui S; Lindahl, Erik; Carlsson, Jens; Harris, R Adron
2013-11-01
GABA(A) receptors play a crucial role in the actions of general anesthetics. The recently published crystal structure of the general anesthetic propofol bound to Gloeobacter violaceus ligand-gated ion channel (GLIC), a bacterial homolog of GABA(A) receptors, provided an opportunity to explore structure-based ligand discovery for pentameric ligand-gated ion channels (pLGICs). We used molecular docking of 153,000 commercially available compounds to identify molecules that interact with the propofol binding site in GLIC. In total, 29 compounds were selected for functional testing on recombinant GLIC, and 16 of these compounds modulated GLIC function. Active compounds were also tested on recombinant GABA(A) receptors, and point mutations around the presumed binding pocket were introduced into GLIC and GABA(A) receptors to test for binding specificity. The potency of active compounds was only weakly correlated with properties such as lipophilicity or molecular weight. One compound was found to mimic the actions of propofol on GLIC and GABA(A), and to be sensitive to mutations that reduce the action of propofol in both receptors. Mutant receptors also provided insight about the position of the binding sites and the relevance of the receptor's conformation for anesthetic actions. Overall, the findings support the feasibility of the use of virtual screening to discover allosteric modulators of pLGICs, and suggest that GLIC is a valid model system to identify novel GABA(A) receptor ligands.
Social relations and loneliness among older patients consulting their general practitioner
Due, Tina Drud; Sandholdt, Håkon; Waldorff, Frans Boch
2017-01-01
INTRODUCTION: Social relations are important for people and affect their quality of life, morbidity and mortality. This holds true especially for older persons. General practitioners (GPs) are in a unique position to address social relations and loneliness; however, no GP population-based studies have assessed older patients' social relations and loneliness. The aim of this study was to analyse the social relations and loneliness of patients aged 65 years and above consulting their GP.METHODS...
Liang, Christopher T. H.; Li,Lisa C.; Kim, Bryan S. K.
2004-01-01
The development of the 29-item Asian American Racism-Related Stress Inventory (AARRSI) is presented. In the first study, data from 161 Asian American respondents were subjected to an exploratory factor analysis, which yielded 3 subscales composed of Socio-Historical Racism (14 items), General Racism (8 items), and Perpetual Foreigner Racism (7…
Building the general relativity and gravitation community during the Cold War
Lalli, Roberto
2017-01-01
This monograph presents a new perspective on the history of general relativity. It outlines the attempts to establish an institutional framework for the promotion of the field during the Cold War. Readers will learn the difficulties that key figures experienced and overcame during this period of global conflict. The author analyzes the subtle interconnections between scientific and political factors. He shows how politics shaped the evolution of general relativity, even though it is a field with no military applications. He also details how different scientists held quite different views about what “political” meant in their efforts to pursue international cooperation. The narrative examines the specific epistemic features of general relativity that helped create the first official, international scientific society. It answers: Why did relativity bring about this unique result? Was it simply the product of specific actions of particular actors having an illuminated view of international relations in the...
Directory of Open Access Journals (Sweden)
Chia-Yi Wu
2016-06-01
Conclusion: The BSRS-5R was validated as an efficient checklist to screen for psychiatric morbidity and suicide ideation in the general public. The result is valuable in translating into general medical and community settings for early detection of suicide ideation.
Chambless, Dianne L; Sharpless, Brian A; Rodriguez, Dianeth; McCarthy, Kevin S; Milrod, Barbara L; Khalsa, Shabad-Ratan; Barber, Jacques P
2011-12-01
Aims of this study were (a) to summarize the psychometric literature on the Mobility Inventory for Agoraphobia (MIA), (b) to examine the convergent and discriminant validity of the MIA's Avoidance Alone and Avoidance Accompanied rating scales relative to clinical severity ratings of anxiety disorders from the Anxiety Disorders Interview Schedule (ADIS), and (c) to establish a cutoff score indicative of interviewers' diagnosis of agoraphobia for the Avoidance Alone scale. A meta-analytic synthesis of 10 published studies yielded positive evidence for internal consistency and convergent and discriminant validity of the scales. Participants in the present study were 129 people with a diagnosis of panic disorder. Internal consistency was excellent for this sample, α=.95 for AAC and .96 for AAL. When the MIA scales were correlated with interviewer ratings, evidence for convergent and discriminant validity for AAL was strong (convergent r with agoraphobia severity ratings=.63 vs. discriminant rs of .10-.29 for other anxiety disorders) and more modest but still positive for AAC (.54 vs. .01-.37). Receiver operating curve analysis indicated that the optimal operating point for AAL as an indicator of ADIS agoraphobia diagnosis was 1.61, which yielded sensitivity of .87 and specificity of .73. Copyright Â© 2011. Published by Elsevier Ltd.
Chambless, Dianne L.; Sharpless, Brian A.; Rodriguez, Dianeth; McCarthy, Kevin S.; Milrod, Barbara L.; Khalsa, Shabad-Ratan; Barber, Jacques P.
2012-01-01
Aims of this study were (a) to summarize the psychometric literature on the Mobility Inventory for Agoraphobia (MIA), (b) to examine the convergent and discriminant validity of the MIA’s Avoidance Alone and Avoidance Accompanied rating scales relative to clinical severity ratings of anxiety disorders from the Anxiety Disorders Interview Schedule (ADIS), and (c) to establish a cutoff score indicative of interviewers’ diagnosis of agoraphobia for the Avoidance Alone scale. A meta-analytic synthesis of 10 published studies yielded positive evidence for internal consistency and convergent and discriminant validity of the scales. Participants in the present study were 129 people with a diagnosis of panic disorder. Internal consistency was excellent for this sample, α = .95 for AAC and .96 for AAL. When the MIA scales were correlated with interviewer ratings, evidence for convergent and discriminant validity for AAL was strong (convergent r with agoraphobia severity ratings = .63 vs. discriminant rs of .10-.29 for other anxiety disorders) and more modest but still positive for AAC (.54 vs. .01-.37). Receiver operating curve analysis indicated that the optimal operating point for AAL as an indicator of ADIS agoraphobia diagnosis was 1.61, which yielded sensitivity of .87 and specificity of .73. PMID:22035997
Mangueira, Suzana de Oliveira; Lopes, Marcos Venícios de Oliveira
2016-10-01
To evaluate the clinical validity indicators for the nursing diagnosis of dysfunctional family processes related to alcohol abuse. Alcoholism is a chronic disease that negatively affects family relationships. Studies on the nursing diagnosis of dysfunctional family processes are scarce in the literature. This diagnosis is currently composed of 115 defining characteristics, hindering their use in practice and highlighting the need for clinical validation. This was a diagnostic accuracy study. A sample of 110 alcoholics admitted to a reference centre for alcohol treatment was assessed during the second half of 2013 for the presence or absence of the defining characteristics of the diagnosis. Operational definitions were created for each defining characteristic based on concept analysis and experts evaluated the content of these definitions. Diagnostic accuracy measures were calculated from latent class models with random effects. All 89 clinical indicators were found in the sample and a set of 24 clinical indicators was identified as clinically valid for a diagnostic screening for family dysfunction from the report of alcoholics. Main clinical indicators with high specificity included sexual abuse, disturbance in academic performance in children and manipulation. The main indicators that showed high sensitivity values were distress, loss, anxiety, low self-esteem, confusion, embarrassment, insecurity, anger, loneliness, deterioration in family relationships and disturbance in family dynamics. Eighteen clinical indicators showed a high capacity for diagnostic screening for alcoholics (high sensitivity) and six indicators can be used for confirmatory diagnosis (high specificity). © 2016 John Wiley & Sons Ltd.
Garcia, Patrícia Petromilli Nordi Sasso; Presoto, Cristina Dupim; Maroco, João; Campos, Juliana Alvares Duarte Bonini
2016-05-26
Dentists are exposed to occupational hazards, such as musculoskeletal disorders, in which symptoms can manifest early in clinical practice. To estimate the reliability and validity of the Portuguese version of the "Questionnaire on work-related activities that may contribute to musculoskeletal symptoms" when applied to dental students. 553 Brazilian students participated in the study. The one-factor structure originally proposed was tested through confirmatory factor analysis (CFA) using the indexes c2/df, CFI, GFI, and RMSEA. After observing an inadequate good fit (c2/df=7.140, CFI=0.791, GFI=0.778, RMSEA=0.129), the sample was subdivided into 3 groups and an exploratory factor analysis was conducted (EFA) (n=255). A CFA was then conducted using a subsample (n=113). To test the invariance of the obtained factorial solution, a multi-group analysis was performed using a third sample, independent from the others (n=185). The convergent (AVE) and discriminant (r2) validity were assessed. The composite reliability (CR), Cronbach's alpha coefficient (a), and intra-class correlation coefficient (r) were calculated. In the EFA, 3 factors were extracted: "Repetitiveness," "Working posture," and "External factors" (c2=21895.154; pinternal consistency, and reproducibility were adequate for all factors (CR=0.736-0.883; a=0.747-0.876; r=0.729-0.940). The questionnaire proved to be reliable and valid for the sample of dentistry students if the three-factor model is used.
Miguel, Susana; Caldeira, Sílvia; Vieira, Margarida
2016-11-17
This article describes the adequacy of the Q methodology as a new option for the validation of nursing diagnoses related to subjective foci. Discussion paper about the characteristics of the Q methodology. This method has been used in nursing research particularly related to subjective concepts and includes both a quantitative and qualitative dimension. The Q methodology seems to be an adequate and innovative method for the clinical validation of nursing diagnoses. The validation of nursing diagnoses related to subjective foci using the Q methodology could improve the level of evidence and provide nurses with clinical indicators for clinical reasoning and for the planning of effective interventions. Descrever a adequação da metodologia Q como uma nova opção para a validação clínica de diagnósticos de enfermagem relacionados com focos subjetivos. MÉTODOS: Artigo de discussão sobre as características da metodologia Q. Este método tem sido utilizado na pesquisa em enfermagem relacionada com conceitos subjetivos e inclui em simultâneo uma vertente qualitativa e quantitativa. CONCLUSÕES: A metodologia Q parece ser uma opção metodológica adequada para a validação clínica de diagnósticos de enfermagem. IMPLICAÇÕES PARA A PRÁTICA: A utilização da metodologia Q na validação clínica de diagnósticos de enfermagem relacionados com focos subjetivos pode melhorar o nível e evidência e facilitar o raciocínio clínico dos enfermeiros, ao providenciar indicadores clínicos também necessários ao desenvolvimento de intervenções efetivas. © 2016 NANDA International, Inc.
Differences in social relations between persons with type 2 diabetes and the general population
DEFF Research Database (Denmark)
Hempler, Nana Folmann; Ekholm, Ola; Willaing, Ingrid
2013-01-01
with type 2 diabetes. The aim of this study was to investigate whether persons with type 2 diabetes have poorer social relations than the general population. Methods: We conducted a cross-sectional survey in three settings: a specialist diabetes clinic (SDC) (n = 1084), a web panel (WP) consisting...... of persons with type 2 diabetes (n = 1491) and a sample from the 2010 Danish Health and Morbidity Survey, representative of the general population (n = 15,165). We compared social relations using multivariate logistic regression. Results: Compared to the general population, persons with type 2 diabetes more.......08-1.41). Conclusions: Our findings suggest that persons with type 2 diabetes have poorer social relations than the general population. From a public health point of view, special attention is needed with regards to strengthening existing networks and establishing alternative networks among persons with type 2 diabetes....
Garet, Martin; Boudet, Gil; Montaurier, Christophe; Vermorel, Michel; Coudert, Jean; Chamoux, Alain
2005-05-01
Measuring physical workload in occupational medicine is fundamental for risk prevention. An indirect measurement of total and relative energy expenditure (EE) from heart rate (HR) is widely used but it has never been validated. The aim of this study was to validate this HR-estimated energy expenditure (HREEE) method against whole-body indirect calorimetry. Twenty-four-hour HR and EE values were recorded continuously in a calorimetric chambers for 52 adult males and females (19-65 years). An 8-h working period was retained, comprising several exercise sessions on a cycloergometer at intensities up to 65% of the peak rate of oxygen uptake. HREEE was calculated with reference to cardiac reserve. A corrected HREEE (CHREEE) was also calculated with a modification to the lowest value of cardiac reserve. Both values were further compared to established methods: the flex-HR method, and the use of a 3rd order polynomial relationship to estimate total and relative EE. No significant difference was found in total EE when measured in a calorimetric chamber or estimated from CHREEE for the working period. A perfect linear and identity relationship was found between CHREEE and energy reserve values for intensities ranging from 15% to 65%. Relative physical workload can be accurately assessed from HR recordings when expressed in CHREEE between 15% to 65%, and EE can be accurately estimated using the CHREEE method.
Hoffman, Eric W; Pinkleton, Bruce E; Weintraub Austin, Erica; Reyes-Velázquez, Wanda
2014-01-01
Alcohol marketers have increasingly moved their advertising efforts into digital and social media venues. As a result, the purpose of this study is to investigate associations between students' use of social media, their exposure to alcohol marketing messages through social media, and their alcohol-related beliefs and behaviors. Public and private university students (N = 637) participated November and December 2011 and April 2012. College students completed online surveys to measure their exposure to social and online media generally, as well as their alcohol-related digital media use and alcohol use. Use of social media related to alcohol marketing predicted alcohol consumption and engaging in risky behaviors, whereas the use of social media more generally did not. Students' use of alcohol-related social media-marketing content associates with their problem drinking. Results have implications for alcohol abuse reduction efforts targeted at college students and suggest the importance of considering social, cultural, and cognitive factors in campaign planning and design.
Beyond face validity - A comment on Nicholls, Licht, and Pearl. [gender-related personality traits
Spence, Janet T.; Helmreich, Robert L.
1983-01-01
In their discussion of the Bem Sex Role Inventory (BSRI; Bem, 1974) and the Personal Attributes Questionnaire (PAQ; Spence and Helmrich, 1978), Nicholls, et al. (1982) blur two issues. The first concerns the legitimacy of equating the clusters of gender-related personality traits tapped by these instruments with the global constructs of masculinity and feminity. The second concerns item similarity between the PAQ and BSRI M scales and measures of self-esteem and the question of whether the several instruments measure the same or separable constructs. Decisions about each of these issues involve complex considerations that do not directly involve face validity.
Raymond, Mark R; Kahraman, Nilufer; Swygert, Kimberly A; Balog, Kevin P
2011-10-01
Prior studies report large score gains for examinees who fail and later repeat standardized patient (SP) assessments. Although research indicates that score gains on SP exams cannot be attributed to memorizing previous cases, no studies have investigated the empirical validity of scores for repeat examinees. This report compares single-take and repeat examinees in terms of both internal (construct) validity and external (criterion-related) validity. Data consisted of test scores for examinees who took the United States Medical Licensing Examination Step 2 Clinical Skills (CS) exam between July 16, 2007, and September 12, 2009. The sample included 12,090 examinees who completed Step 2 CS on one occasion and another 4,030 examinees who completed the exam on two occasions. The internal measures included four separately scored performance domains of the Step 2 CS examination, whereas the external measures consisted of scores on three written assessments of medical knowledge (Step 1, Step 2 clinical knowledge, and Step 3). The authors subjected the four Step 2 CS domains to confirmatory factor analysis and evaluated correlations between Step 2 CS scores and the three written assessments for single-take and repeat examinees. The factor structure for repeat examinees on their first attempt was markedly different from the factor structure for single-take examinees, but it became more similar to that for single-take examinees by their second attempt. Scores on the second attempt correlated more highly with all three external measures. The findings support the validity of scores for repeat examinees on their second attempt.
Chia, Yook Chin; Gray, Sarah Yu Weng; Ching, Siew Mooi; Lim, Hooi Min; Chinna, Karuthan
2015-05-19
This study aims to examine the validity of the Framingham general cardiovascular disease (CVD) risk chart in a primary care setting. This is a 10-year retrospective cohort study. A primary care clinic in a teaching hospital in Malaysia. 967 patients' records were randomly selected from patients who were attending follow-up in the clinic. Baseline demographic data, history of diabetes and smoking, blood pressure (BP), and serum lipids were captured from patient records in 1998. Each patient's Framingham CVD score was computed from these parameters. All atherosclerotic CVD events occurring between 1998 and 2007 were counted. In 1998, mean age was 57 years with 33.8% men, 6.1% smokers, 43.3% diabetics and 59.7% hypertensive. Median BP was 140/80 mm Hg and total cholesterol 6.0 mmol/L (1.3). The predicted median Framingham general CVD risk score for the study population was 21.5% (IQR 1.2-30.0) while the actual CVD events that occurred in the 10 years was 13.1% (127/967). The median CVD points for men was 30.0, giving them a CVD risk of more than 30%; for women it is 18.5, a CVD risk of 21.5%. Our study found that the Framingham general CVD risk score to have moderate discrimination with an area under the receiver operating characteristic curve (AUC) of 0.63. It also discriminates well for Malay (AUC 0.65, p=0.01), Chinese (AUC 0.60, p=0.03), and Indians (AUC 0.65, p=0.001). There was good calibration with Hosmer-Lemeshow test χ(2)=3.25, p=0.78. Taking into account that this cohort of patients were already on treatment, the Framingham General CVD Risk Prediction Score predicts fairly accurately for men and overestimates somewhat for women. In the absence of local risk prediction charts, the Framingham general CVD risk prediction chart is a reasonable alternative for use in a multiethnic group in a primary care setting. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Development and validation of the alcohol-related God locus of control scale.
Murray, Thomas S; Goggin, Kathy; Malcarne, Vanessa L
2006-03-01
Control beliefs and spirituality appear to be important factors in recovery from alcoholism. However, the integration of these two constructs has received little attention, and the relationship of spiritually related control beliefs to recovery remains unclear. Currently no measures exist to specifically assess these beliefs. To address this need, the Alcohol-Related God Locus of Control scale (AGLOC) was developed. This 12-item self-report measure assesses perceptions of God/Higher Power's role in recovery from alcoholism. The AGLOC was administered to 144 recovering alcoholics attending Alcoholics Anonymous meetings. Exploratory factor analysis yielded a two-factor solution with one factor related to attributions of God control over initial cessation of drinking (Cessation) and the other factor related to attributions of God control over one's continued maintenance of sobriety (Maintenance). Both subscales and the overall scale demonstrated adequate to high internal consistency. Demonstrating convergent and discriminant validity, the total AGLOC scale and the Cessation subscale were significantly but moderately correlated with spirituality (both frequency and importance), and independent of perceptions of internal control over drinking. Maintenance subscale scores were inversely associated with internal drinking-related scores and were not associated with spiritual importance or frequency of spiritual practice. Findings support the utility of this instrument for the assessment of alcohol-related God/Higher Power locus of control beliefs in an alcoholic population and suggest the importance of further research on changes in alcohol-related God control beliefs throughout the course of recovery.
Energy Technology Data Exchange (ETDEWEB)
Ludyk, Guenter [Bremen Univ. (Germany). Physics and Electrical Engineering
2013-11-01
Derives the fundamental equations of Einstein's theory of special and general relativity using matrix calculus, without the help of tensors. Provides necessary mathematical tools in a user-friendly way, either directly in the text or in the appendices. Appendices contain an introduction to classical dynamics as a refresher of known fundamental physics. Rehearses vector and matrix calculus, differential geometry, and some special solutions of general relativity in the appendices. This book is an introduction to the theories of Special and General Relativity. The target audience are physicists, engineers and applied scientists who are looking for an understandable introduction to the topic - without too much new mathematics. The fundamental equations of Einsteins theory of Special and General Relativity are derived using matrix calculus, without the help of tensors. This feature makes the book special and a valuable tool for scientists and engineers with no experience in the field of tensor calculus. In part I the foundations of Special Relativity are developed, part II describes the structure and principle of General Relativity. Part III explains the Schwarzschild solution of spherical body gravity and examines the ''Black Hole'' phenomenon. Any necessary mathematical tools are user friendly provided, either directly in the text or in the appendices.
Platsidou, Maria; Agaliotis, Ioannis
2017-01-01
The role of empathy in the teaching profession has been vastly investigated in relation to its effect on students, but research on how teachers' empathy affects their own well-being at work is limited. This study investigated empathy and instructional assignment-related stress factors of primary school teachers serving in general or special…
General or Technical High School: Parameters Related to Greek Students' Choice
Christopoulou, Anthoula; Kounenou, Kalliope
2012-01-01
This research attempts to examine the demographic characteristics of Greek adolescents who choose either general or technical high schools as well as the parameters related to students' specific educational decision. The sample of the survey includes 198 students from both schools. Results showed that students' choice was not directly related to…
Visible Age-Related Signs and Risk of Ischemic Heart Disease in the General Population
DEFF Research Database (Denmark)
Christoffersen, Mette; Frikke-Schmidt, Ruth; Schnohr, Peter
2014-01-01
BACKGROUND: Cardiovascular disease is 1 of the most common age-related diseases, and also 1 of the most common causes of death in the general population. We tested the hypothesis that visible age-related signs associate with risk of ischemic heart disease (IHD), myocardial infarction (MI), and de...
The Problem of the Particular and its Relation to the General in Mathematics Education
Font, Vicenc; Contreras, Angel
2008-01-01
Research in the didactics of mathematics has shown the importance of the problem of the particular and its relation to the general in teaching and learning mathematics as well as the complexity of factors related to them. In particular, one of the central open questions is the nature and diversity of objects that carry out the role of particular…
7 CFR 319.40-2 - General prohibitions and restrictions; relation to other regulations.
2010-01-01
... 7 Agriculture 5 2010-01-01 2010-01-01 false General prohibitions and restrictions; relation to... (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES...; relation to other regulations. (a) Permit required. Except for regulated articles exempted from this...
Ochoa, Susana; Martínez-Zambrano, Francisco; Garcia-Franco, Mar; Vilamala, Sonia; Ribas, Maria; Arenas, Oti; Garcia-Morales, Esther; Álvarez, Irene; Escartin, Gemma; Villellas, Raul; Escandell, Maria Jose; Martínez-Raves, Mónica; López-Arias, Elisabeth; Cunyat, Christian; Haro, Josep Maria
2015-10-01
Self-stigma specifically in people with schizophrenia has been little studied. The aims of the present study were to validate a new instrument for the assessment of self-stigma (SSQ) and to assess the relationship between self-stigma and social functioning in people with schizophrenia. A sample of 76 people with schizophrenia was assessed at two moments in time with the SSQ, the PDD (stigma), two scales of social functioning (LSP, SFS), and a scale of general functioning (GAF). The results indicated that SSQ presented good psychometric properties, with Cronbach's alpha ranging between 0.75 and 0.901. The stability of the instrument was between 0.836 and 0.402. Three factors were found in the factor analysis (social discrimination, perceived capabilities, concealment of the disease), explaining 62.66% of the total variance. A relationship was found between self-stigma and social functioning in people with schizophrenia, especially in relation to social contact. In conclusion, the SSQ seems to be a valid and reliable questionnaire for the assessment of self-stigma in people with schizophrenia, and interventions should be designed to cope with self-stigma in order to improve the social functioning of people who suffer schizophrenia. Copyright © 2015 Elsevier Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Hilde A E Geraedts
Full Text Available Regular physical activity is essential for older adults to stay healthy and independent. However, daily physical activity is generally low among older adults and mainly consists of activities such as standing and shuffling around indoors. Accurate measurement of this low-energy expenditure daily physical activity is crucial for stimulation of activity. The objective of this study was to assess the validity of a necklace-worn sensor-based method for detecting time-on-legs and daily life mobility related postures in older adults. In addition user opinion about the practical use of the sensor was evaluated. Twenty frail and non-frail older adults performed a standardized and free movement protocol in their own home. Results of the sensor-based method were compared to video observation. Sensitivity, specificity and overall agreement of sensor outcomes compared to video observation were calculated. Mobility was assessed based on time-on-legs. Further assessment included the categories standing, sitting, walking and lying. Time-on-legs based sensitivity, specificity and percentage agreement were good to excellent and comparable to laboratory outcomes in other studies. Category-based sensitivity, specificity and overall agreement were moderate to excellent. The necklace-worn sensor is considered an acceptable valid instrument for assessing home-based physical activity based upon time-on-legs in frail and non-frail older adults, but category-based assessment of gait and postures could be further developed.
Relative validation of the KiGGS Food Frequency Questionnaire among adolescents in Germany
2011-01-01
Background The aim of this study was to determine the relative validity of the self-administered Food Frequency Questionnaire (FFQ) "What do you eat?", which was used in the German National Health Interview and Examination Survey for Children and Adolescents (KiGGS 2003-2006). Methods The validation was conducted in the EsKiMo Nutrition Module, a subsample of KiGGS. The study population included 1,213 adolescents aged between 12 and 17. A modified diet history interview DISHES (Dietary Interview Software for Health Examination Studies) was used as the reference method. In order to compare the food groups, the data assessed with both instruments were aggregated to 40 similar food groups. The statistical analysis included calculating and comparing Spearman's correlation coefficients, calculating the mean difference between both methods, and ranking participants (quartiles) according to food group consumption, including weighted kappa coefficients. Correlations were also evaluated for relative body weight and socioeconomic status subgroups. Results In the total study population the Spearman correlation coefficients ranged from 0.22 for pasta/rice to 0.69 for margarine; most values were 0.50 and higher. The mean difference ranged between 1.4% for milk and 100.3% for pasta/rice. The 2.5 percentiles and 97.5 percentiles indicated a wide range of differences. Classifications in the same and adjacent quartile varied between 70.1% for pasta/rice and 90.8% for coffee. For most groups, Cohen's weighted kappa showed values between 0.21 and 0.60. Only for white bread and pasta/rice were values less than 0.20. Most of the 40 food groups showed acceptable to good correlations in all investigated subgroups concerning age, sex, body weight and socio-economic status. Conclusions The KiGGS FFQ showed fair to moderate ranking validity except for pasta/rice and white bread. However, the ability to assess absolute intakes is limited. The correlation coefficients for most food items were
Determining relative importance of variables in developing and validating predictive models
Directory of Open Access Journals (Sweden)
Atenafu Eshetu G
2009-09-01
Full Text Available Abstract Background Multiple regression models are used in a wide range of scientific disciplines and automated model selection procedures are frequently used to identify independent predictors. However, determination of relative importance of potential predictors and validating the fitted models for their stability, predictive accuracy and generalizability are often overlooked or not done thoroughly. Methods Using a case study aimed at predicting children with acute lymphoblastic leukemia (ALL who are at low risk of Tumor Lysis Syndrome (TLS, we propose and compare two strategies, bootstrapping and random split of data, for ordering potential predictors according to their relative importance with respect to model stability and generalizability. We also propose an approach based on relative increase in percentage of explained variation and area under the Receiver Operating Characteristic (ROC curve for developing models where variables from our ordered list enter the model according to their importance. An additional data set aimed at identifying predictors of prostate cancer penetration is also used for illustrative purposes. Results Age is chosen to be the most important predictor of TLS. It is selected 100% of the time using the bootstrapping approach. Using the random split method, it is selected 99% of the time in the training data and is significant (at 5% level 98% of the time in the validation data set. This indicates that age is a stable predictor of TLS with good generalizability. The second most important variable is white blood cell count (WBC. Our methods also identified an important predictor of TLS that was otherwise omitted if relying on any of the automated model selection procedures alone. A group at low risk of TLS consists of children younger than 10 years of age, without T-cell immunophenotype, whose baseline WBC is 9/L and palpable spleen is Conclusion Our model selection procedures based on bootstrap re-sampling and
Weingarden, Hilary; Renshaw, Keith D; Davidson, Eliza; Wilhelm, Sabine
2017-07-01
Body Dysmorphic Disorder (BDD) is characterized by a preoccupation with a perceived flaw in appearance and repetitive avoidance behaviors. BDD involves severe psychosocial outcomes (e.g., depression, suicidality, functional impairment). Identifying correlates of BDD symptoms and outcomes can inform treatment. Shame, a painful emotion felt in response to critical self-judgment, may be one key correlate. However, research on shame in BDD is scarce and previous studies have not distinguished general shame from body shame. This study examines the relative relationships between body shame and general shame with body dysmorphic phenomenology and psychosocial outcomes. Participants (N = 184) were recruited online via BDD organizations and completed a survey. Path analysis was used to examine associations between body and general shame with 1) body dysmorphic phenomenology and 2) depression severity, suicide risk, and functional impairment. Both types of shame were differentially related to outcomes. Body shame was more strongly related to phenomenology, whereas general shame was more strongly related to psychosocial outcomes. Thus, it may be important for BDD treatment to focus on reducing both general and body shame. Further research should evaluate whether current treatments adequately address and reduce general and body shame, and whether addressing shame promotes better treatment outcomes.
Relative validation of Block Kids Food Screener for dietary assessment in children and adolescents.
Hunsberger, Monica; O'Malley, Jean; Block, Torin; Norris, Jean C
2015-04-01
Food frequency questionnaires (FFQs) are less time consuming and inexpensive instruments for collecting dietary intake when compared with 24-h dietary recalls or double-labelled water; however, the validation of FFQ is important as incorrect information may lead to biased conclusions about associations. Therefore, the relative validity of the Block Kids Food Screener (BKFS) developed for use with children was examined in a convenience sample of 99 youth recruited from the Portland, OR metropolitan area. Three 24-h dietary recalls served as the reference. The relative validity was analysed after natural log transformation of all variables except glycaemic index prior to correlation analysis. Daily cup equivalent totals from the BKFS and 'servings' from 24-h recalls were used to compute average daily intake of fruits, vegetables, potatoes, whole grains, legumes, meat/fish/poultry and dairy. Protein grams (g), total kcalories, glycaemic index (glucose reference), glycaemic load (glucose reference), total saturated fat (g) and added sugar (g) were also calculated by each instrument. The correlation between data obtained from the two instruments was corrected for the within-subject variation in food intake reported by the 24-h recalls using standard nutritional assessment methodology. The de-attenuated correlations in nutritional intake between the two dietary assessment instruments ranged from 0.526 for vegetables, to 0.878 for potatoes. The 24-h recall estimated higher levels of saturated fat and added sugar consumption, higher glycaemic loads and glycaemic indices; the de-attenuatted correlations of these measures ranged from 0.478 to 0.768. Assessment of Bland-Altman plots indicated no systematic difference between the two instruments for vegetable, dairy and meat/fish/poultry fat consumption. BKFS is a useful dietary assessment instrument for the nutrients and food groups it was designed to assess in children age 10-17 years. © 2012 Blackwell Publishing Ltd.
Neidert, Marian C; Lawton, Michael T; Kim, Louis J; Nerva, John D; Kurisu, Kaoru; Ikawa, Fusao; Konczalla, Juergen; Dinc, Nazife; Seifert, Volker; Habdank-Kolaczkowski, Julian; Hatano, Taketo; Hayase, Makoto; Podlesek, Dino; Schackert, Gabriele; Wanet, Thomas; Gläsker, Sven; Griessenauer, Christoph J; Ogilvy, Christopher S; Kneist, Andreas; Sure, Ulrich; Seifert, Burkhardt; Regli, Luca; Bozinov, Oliver; Burkhardt, Jan-Karl
2017-10-06
The recently published arteriovenous malformation-related intracerebral haemorrhage (AVICH) score showed better outcome prediction for patients with arteriovenous malformation (AVM)-related intracerebral haemorrhage (ICH) than other AVM or ICH scores. Here we present the results of a multicentre, external validation of the AVICH score. All participating centres (n=11) provided anonymous data on 325 patients to form the Spetzler-Martin (SM) grade, the supplemented SM (sSM) grade, the ICH score and the AVICH score. Modified Rankin score (mRS) at last follow-up (mean 25.6 months) was dichotomized into favourable (mRS 0-2, n=210) and unfavourable (mRS 3-6;n=115). Univariate and AUROC analyses were performed to validate the AVICH score. Except nidus structure and AVM size, all single parameters forming the SM, sSM, ICH and AVICH score and the scores itself were significantly different between both outcome groups in the univariate analysis. The AVICH score was confirmed to be the highest predictive outcome score with an AUROC of 0.765 compared with 0.705 for the ICH score and 0.682 for the sSM grade. The multicentre-validated AVICH score predicts clinical outcome superior to pre-existing scores. We suggest the routine use of this score for future clinical outcome prediction and in clinical research. NCT02920645. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Neuro-QoL health-related quality of life measurement system: Validation in Parkinson's disease.
Nowinski, Cindy J; Siderowf, Andrew; Simuni, Tanya; Wortman, Catherine; Moy, Claudia; Cella, David
2016-05-01
Neuro-QoL is a multidimensional patient-reported outcome measurement system assessing aspects of physical, mental, and social health identified by neurology patients and caregivers as important. One of the first neurology-specific patient-reported outcome measure systems created using modern test development methods, Neuro-Qol enables brief, yet precise, assessment and the ability to conduct both PD-specific and cross-disease comparisons. We present results of Neuro-QoL clinical validation using a sample of PD patients. A total of 120 PD patients recruited from academic medical centers were assessed at baseline, 1 week, and 6 months. Assessments included Neuro-QoL and general and PD-specific validity measures. Participants were 62% male and 95% white (average age = 66); H & Y stages were 1 (16%), 2 (61%), 3 (18%), and 4 (5%). Internal consistency and test-retest reliability of Neuro-QoL ranged from Cronbach's alphas = 0.81 to 0.94 with intraclass correlation coefficients = 0.66 to 0.80. Pearson's correlations between Neuro-QoL and legacy measures were generally moderate and in expected directions. UPDRS Part 2 was moderately correlated with Neuro-QoL Upper Extremity and Mobility, respectively (r's = -0.44; -0.59). Parkinson's Disease Questionnaire-39 and Neuro-QoL measures of similar constructs showed strong-to-moderate correlations (r's = 0.70-0.44). Neuro-QoL measures of fatigue, mobility, positive emotion, and emotional/behavioral control showed responsiveness to self-reported change. Neuro-QoL is valid for use in PD clinical research. Reliability for all but two measures is sufficient for group comparisons, with some evidence supporting responsiveness to change. Neuro-QoL possesses characteristics, such as brevity, flexibility in administration, and suitability, for cross-disease comparisons that may be advantageous to users in a variety of settings. © 2016 Movement Disorder Society. © 2016 International Parkinson and Movement Disorder
Van Iddekinge, Chad H; Morgeson, Frederick P; Schleicher, Deidra J; Campion, Michael A
2011-09-01
Despite recent interest in the practice of allowing job applicants to retest, surprisingly little is known about how retesting affects 2 of the most critical factors on which staffing procedures are evaluated: subgroup differences and criterion-related validity. We examined these important issues in a sample of internal candidates who completed a job-knowledge test for a within-job promotion. This was a useful context for these questions because we had job-performance data on all candidates (N = 403), regardless of whether they passed or failed the promotion test (i.e., there was no direct range restriction). We found that retest effects varied by subgroup, such that females and younger candidates improved more upon retesting than did males and older candidates. There also was some evidence that Black candidates did not improve as much as did candidates from other racial groups. In addition, among candidates who retested, their retest scores were somewhat better predictors of subsequent job performance than were their initial test scores (rs = .38 vs. .27). The overall results suggest that retesting does not negatively affect criterion-related validity and may even enhance it. Furthermore, retesting may reduce the likelihood of adverse impact against some subgroups (e.g., female candidates) but increase the likelihood of adverse impact against other subgroups (e.g., older candidates). PsycINFO Database Record (c) 2011 APA, all rights reserved
Stein, Michelle B; Slavin-Mulford, Jenelle; Sinclair, S Justin; Siefert, Caleb J; Blais, Mark A
2012-01-01
The Social Cognition and Object Relations Scale-Global rating method (SCORS-G; Stein, Hilsenroth, Slavin-Mulford, & Pinsker, 2011; Westen, 1995) measures the quality of object relations in narrative material. This study employed a multimethod approach to explore the structure and construct validity of the SCORS-G. The Thematic Apperception Test (TAT; Murray, 1943) was administered to 59 patients referred for psychological assessment at a large Northeastern U.S. hospital. The resulting 301 TAT narratives were rated using the SCORS-G method. The 8 SCORS variables were found to have high interrater reliability and good internal consistency. Principal components analysis revealed a 3-component solution with components tapping emotions/affect regulation in relationships, self-image, and aspects of cognition. Next, the construct validity of the SCORS-G components was explored using measures of intellectual and executive functioning, psychopathology, and normal personality. The 3 SCORS-G components showed unique and theoretically meaningful relationships across these broad and diverse psychological measures. This study demonstrates the value of using a standardized scoring method, like the SCORS-G, to reveal the rich and complex nature of narrative material.
Ruehlman, Linda S; Karoly, Paul; Newton, Craig; Aiken, Leona S
2005-01-01
From a biopsychosocial perspective, assessing chronic pain's psychological impact should involve at minimum the measurement of pain severity, functional interference, and pain-related emotional burden. This article details the development of a brief instrument, the 15-item Profile of Chronic Pain: Screen (PCP:S), designed to address these three key elements in a national (US) sample of over 2400 individuals recruited via random digit dialing. Retest reliability, internal consistency, and preliminary validity were excellent. The scales also demonstrated minimal social desirability response bias. A series of confirmatory factor analyses on several distinct samples revealed a stable, 3-factor solution reflecting pain severity, interference, and emotional burden. Finally, national norms were developed by gender and three age groups. In view of its strong psychometric properties, the PCP:S has the potential to serve as a brief, cost-effective assessment tool for identifying individuals whose chronic pain merits more detailed psychosocial evaluation.
Age-Related Differences in OMNI-RPE Scale Validity in Youth: A Longitudinal Analysis.
Gammon, Catherine; Pfeiffer, Karin A; Pivarnik, James M; Moore, Rebecca W; Rice, Kelly R; Trost, Stewart G
2016-08-01
RPE scales are used in exercise science research to assess perceptions of physical effort. RPE scale validity has been evaluated by assessing correlations between RPE and physiological indicators. Cross-sectional studies indicate that RPE scale validity improves with age; however, this has not been studied longitudinally. This study aimed to examine age-related trends in OMNI-RPE scale validity, using a longitudinal study design, and HR and oxygen uptake (V˙O2) as criterion measures. Participants performed eleven 5-min activity trials at baseline, 12-, 24-, and 36-month follow-up (V˙O2 data: N = 160; HR data: N = 138). HR and V˙O2 between minutes 2.5 and 4.5 of each activity were recorded. At the end of each activity, participants reported RPE. Children were stratified into the following age-groups: 6-8, 9-10, 11-12, and ≥13 yr. Within-subject correlations between OMNI-RPE and HR/V˙O2 were calculated at each time point. Differences between correlations for consecutive time points were evaluated using 95% confidence intervals. Among children age 6-8 yr at baseline, correlations progressed from 0.67 to 0.78 (V˙O2) and from 0.70 to 0.79 (HR) for 36 months. Among children age 9-10 yr at baseline, the mean within-subject correlation was 0.78 at baseline and 0.81 at 36-month follow-up. Among children age 11-12 and ≥13 yr at baseline, OMNI-RPE ratings demonstrated strong validity (r ≥ 0.82) at each time point. For the 36-month follow-up, OMNI-RPE scale validity improved among children age 6-8 yr at baseline and remained strong among children age 9-10, 11-12, and ≥13 yr at baseline. Moderate correlations for the youngest participants suggest that caution should be used when interpreting OMNI-RPE reports from children younger than 8 yr.
Directory of Open Access Journals (Sweden)
Nir Kshetri
2013-02-01
Full Text Available With an increasing pervasiveness, prevalence and severity of cybercrimes, various metrics, measures and statistics have been developed and used to measure various aspects of this phenomenon. Cybercrime-related data, metrics, and information, however, pose important and difficult dilemmas regarding the issues of reliability, validity, comparability and practical utility. While many of the issues of the cybercrime economy are similar to other underground and underworld industries, this economy also has various unique aspects. For one thing, this industry also suffers from a problem partly rooted in the incredibly broad definition of the term “cybercrime”. This article seeks to provide insights and analysis into this phenomenon, which is expected to advance our understanding into cybercrime-related information.
Deformations of the vacuum solutions of general relativity subjected to linear constraints
Molina, C.
2013-12-01
The problem of deforming geometries is particularly important in the context of constructing new exact solutions of Einstein’s equation. This issue often appears when extensions of the general relativity are treated, for instance in brane world scenarios. In this paper we investigate spacetimes in which the energy-momentum tensor obeys a linear constraint. Extensions of the usual vacuum and electrovacuum solutions of general relativity are derived and an exact solution is presented. The classes of geometries obtained include a wide variety of compact objects, among them black holes and wormholes. The general metric derived in this work generalizes several solutions already published in the literature. Perturbations around the exact solution are also considered.
Swanson, Jennifer R.; Bradley-Johnson, Sharon; Johnson, C. Merle; O'Dell, Anna Rubenaker
2009-01-01
Three studies examine the validity of the Preschool Form of the Cognitive Abilities Scale--Second Edition (CAS-2). Significant high concurrent criterion-related validity correlations, corrected for restricted range, are found between the CAS-2 and the Detroit Test of Learning Ability--Primary: Third Edition for 26 three-year-olds (r[subscript c] =…
Huang, Chiungjung
2012-01-01
This study examined the discriminant and criterion-related validity of achievement goals in predicting academic achievement. Analysis of 151 studies yielded 172 independent samples (N = 52,986) with correlations among achievement goals and between achievement goals and academic achievement. The discriminant validity of achievement goals in the 2-,…
Brouwers, L.A.; Engels, J.A.; Heerkens, Y.F.; van der Beek, A.J.
2015-01-01
Background: Most validated sustainable employability questionnaires are extensive and difficult to obtain. Our objective was to develop a usable and valid tool, a Vitality Scan, to determine possible signs of stagnation in one's functioning related to sustainable employability and to establish the
Livingstone, Holly A.; Day, Arla L.
2005-01-01
Despite the popularity of the concept of emotional intelligence(EI), there is much controversy around its definition, measurement, and validity. Therefore, the authors examined the construct and criterion-related validity of an ability-based EI measure (Mayer Salovey Caruso Emotional Intelligence Test [MSCEIT]) and a mixed-model EI measure…
A Broader View of Relativity General Implications of Lorentz and Poincaré Invariance
Hsu, Jong-Ping
2006-01-01
A Broader View of Relativity shows that there is still new life in old physics. The book examines the historical context and theoretical underpinnings of Einstein's theory of special relativity and describes Broad Relativity, a generalized theory of coordinate transformations between inertial reference frames that includes Einstein's special relativity as a special case. It shows how the principle of relativity is compatible with multiple concepts of physical time and how these different procedures for clock synchronization can be useful for thinking about different physical problems, includin
General tradeoff relations of quantum nonlocality in the Clauser–Horne–Shimony–Holt scenario
Energy Technology Data Exchange (ETDEWEB)
Su, Hong-Yi, E-mail: hongyisu@chonnam.ac.kr [Department of Physics Education, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Chen, Jing-Ling [Theoretical Physics Division, Chern Institute of Mathematics, Nankai University, Tianjin 300071 (China); Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore); Hwang, Won-Young, E-mail: wyhwang@jnu.ac.kr [Department of Physics Education, Chonnam National University, Gwangju 500-757 (Korea, Republic of)
2017-02-15
General tradeoff relations present in nonlocal correlations of bipartite systems are studied, regardless of any specific quantum states and measuring directions. Extensions to multipartite scenarios are possible and very promising. Tsirelson’s bound can be derived out in particular. The close connection with uncertainty relations is also presented and discussed. - Highlights: • Quantum violation of CHSH inequalities is found to satisfy tradeoff relations. • Tsirelson’s bound for quantum mechanics can be directly implied from these tradeoffs. • Tradeoff relations shed new light on uncertainty relations in summation forms.
Kurihara, Yoshimasa
2012-01-01
General characterizations of physical measurements are discussed within the framework of the classical information theory. The uncertainty relation for simultaneous measurements of two physical observables is defined in this framework for generalized dynamic systems governed by a Sturm--Liouville type of equation of motion. In the first step, the reduction of Kennard--Robertson type uncertainties due to boundary conditions with a mean-square error is discussed quantitatively with reference to...
Determinants of general practitioner's cancer-related gut feelings?a prospective cohort study
Donker, G? A; Wiersma, Eva; van der Hoek, Lucas; Heins, Marianne
2016-01-01
Background: General practitioners (GPs) use gut feelings to diagnose cancer in an early stage, but little is known about its impact. Method: Prospective cohort study of patients in 44 general practices throughout the Netherlands, from January 2010 until December 2013. GPs completed a questionnaire regarding gut feelings, patient and GP characteristics, if they noticed a cancer-related gut feeling during patient consultation. Follow-up questionnaires were sent 3 months later requesting informa...
H-theorem for nonlinear Fokker-Planck equations related to generalized thermostatistics
Frank, T. D.; Daffertshofer, A.
2001-06-01
In correspondence to conventional thermostatistics we formulate an H-theorem showing that transients solutions of nonlinear Fokker-Planck equations related to generalized thermostatistics converge to stationary probability densities. The H-theorem is applied to relaxation processes of classical bosons and fermions as proposed by Kaniadakis and Quarati, diffusion processes consistent with the generalized thermostatistics proposed by Tsallis, and stochastic processes with statistical feedback.