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Theoretical Aspects (theoretical + aspect)
Selected AbstractsCopper-Binding Motifs: Structural and Theoretical AspectsHELVETICA CHIMICA ACTA, Issue 5 2003Amy Kaufman, Katz In this paper, we report the results of a study involving the coordination geometries of CuI, CuII, and CuIII crystal structures in the Cambridge Structural Database, and on Cu binding sites in proteins taken from the Protein Data Bank. The motifs used to bind two bridged Cu ions are also described. In addition, we report the results of ab initio molecular-orbital calculations performed on a variety of model CuI/CuII complexes (CuI/CuII,XnYm (X, Y=NH3, SH2); n+m=4; n=0,4) to provide data on the structural and energetic changes that occur in isolated complexes when the oxidation state of the Cu ion is changed from II to I while the coordination number is conserved. The use of such simple ligands in these calculations eliminates constraints on the geometric changes that may be imposed by more-complicated ligands. [source] Theoretical aspects of the internal element connectivity parameterization approach for topology optimizationINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 6 2008Gil Ho Yoon Abstract The internal element connectivity parameterization (I-ECP) method is an alternative approach to overcome numerical instabilities associated with low-stiffness element states in non-linear problems. In I-ECP, elements are connected by zero-length links while their link stiffness values are varied. Therefore, it is important to interpolate link stiffness properly to obtain stably converging results. The main objective of this work is two-fold (1) the investigation of the relationship between the link stiffness and the stiffness of a domain-discretizing patch by using a discrete model and a homogenized model and (2) the suggestion of link stiffness interpolation functions. The effects of link stiffness penalization on solution convergence are then tested with several numerical examples. The developed homogenized I-ECP model can also be used to physically interpret an intermediate design variable state. Copyright © 2008 John Wiley & Sons, Ltd. [source] Residential Facilities in the Community for People with Intellectual Disabilities: How Neighbours' Perceptions are Affected by the Interaction of Facility and Neighbour VariablesJOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 2 2001C. Schwartz The present paper reports a study of neighbours' perceptions of community-based residential facilities for people with intellectual disabilities (IDs). Whereas earlier studies have researched the effect of single variables, the present paper breaks new ground by taking a multidimensional perspective. It analyses neighbourhood acceptance as a variable explainable by interactions between facility variables and the nature of the neighbourhood population itself. Two hundred and eight neighbours of 36 urban community facilities for people with IDs were surveyed, plus the facility managers. The individual characteristics of the neighbours which were found to relate to facility impact included: having young children at home; having a disabled family member; knowing that the neighbourhood contained a facility; and visiting the facility. Pertinent facility variables were: size, degree of supervision, and the pre- and post-entry strategies used by managers to gain local acceptance for the facility. Most importantly, the present study found that none of these variables can be considered or used in isolation. The direction of their effect can be positive or negative according to the variables which they interact with. Theoretical aspects of the findings are discussed and interventions are suggested which might improve the community integration of people with IDs. [source] Theoretical aspects of virus capsid assemblyJOURNAL OF MOLECULAR RECOGNITION, Issue 6 2005Adam Zlotnick Abstract A virus capsid is constructed from many copies of the same protein(s). Molecular recognition is central to capsid assembly. The capsid protein must polymerize in order to create a three-dimensional protein polymer. More than structure is required to understand this self-assembly reaction: one must understand how the pieces come together in solution. Copyright © 2005 John Wiley & Sons, Ltd. [source] On the numerical computation of blowing-up solutions for semilinear parabolic equationsMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 9 2001D. Fayyad Theoretical aspects related to the approximation of the semilinear parabolic equation: $u_t=\Delta u+f(u)$\nopagenumbers\end, with a finite unknown ,blow-up' time Tb have been studied in a previous work. Specifically, for , a small positive number, we have considered coupled systems of semilinear parabolic equations, with positive solutions and ,mass control' property, such that: \def\ve{^\varepsilon}$$u_t\ve=\Delta u\ve+f(u\ve)v\ve\qquad v_t\ve=\Delta v\ve-\varepsilon f(u\ve)v\ve$$\nopagenumbers\end The solution \def\ve{^\varepsilon}$$\{u\ve,v\ve\}$$\nopagenumbers\end of such systems is known to be global. It is shown that $$\|(u^\varepsilon-u)(\, .\, ,t)\|_\infty\leq C(M_T)\varepsilon$$\nopagenumbers\end, \def\lt{\char'74}$t\leq T \lt T_b$\nopagenumbers\end where $M_T=\|u(\, .\, ,T)\|_\infty$\nopagenumbers\end and $C(M_T)$\nopagenumbers\end is given by (6). In this paper, we suggest a numerical procedure for approaching the value of the blow-up time Tb and the blow-up solution u. For this purpose, we construct a sequence $\{M_\eta\}$\nopagenumbers\end, with $\lim_{\eta\rightarrow 0}M_\eta=\infty$\nopagenumbers\end. Correspondingly, for $\varepsilon\leq1/2C(M_\eta+1)=\eta^\alpha$\nopagenumbers\end and \def\lt{\char'74}$0\lt\alpha\lt\,\!1$\nopagenumbers\end, we associate a specific sequence of times $\{T_\varepsilon\}$\nopagenumbers\end, defined by $\|u^\varepsilon(\, .\, ,T_\varepsilon)\|_\infty=M_\eta$\nopagenumbers\end. In particular, when $\varepsilon=\eta\leq\eta^\alpha$\nopagenumbers\end, the resulting sequence $\{T_\varepsilon\equiv T_\eta\}$\nopagenumbers\end, verifies, $\|(u-u^\eta)(\, .\, ,t)\|_\infty\leq{1\over2}(\eta)^{1-\alpha}$\nopagenumbers\end, \def\lt{\char'74}$0\leq t\leq T_\eta\lt T_{\rm b}$\nopagenumbers\end with $\lim_{\eta\rightarrow 0}T_\eta=T_{\rm b}$\nopagenumbers\end. The two special cases of a single-point blow-up where $f(u)=\lambda{\rm e}^u$\nopagenumbers\end and $f(u)=u^p$\nopagenumbers\end are then studied, yielding respectively sequences $\{M_\eta\}$\nopagenumbers\end of order $O(\ln|\ln(\eta)|)$\nopagenumbers\end and $O(\{|\ln(\eta)|\}^{1/p-1})$\nopagenumbers\end. The estimate $|T_\eta-T_{\rm b}|/T_{\rm b}=O(1/|\ln(\eta)|)$\nopagenumbers\end is proven to be valid in both cases. We conduct numerical simulations that confirm our theoretical results. Copyright © 2001 John Wiley & Sons, Ltd. [source] Partial left ventriculectomy in children and adolescentsPEDIATRICS INTERNATIONAL, Issue 2 2000Leonard M Linde Abstract Theoretical aspects, pediatric indications and initial results of a new operation, partial left ventriculectomy, are presented. [source] Historical Figuration: Poetics, Historiography, and New Genre Studies1LITERATURE COMPASS (ELECTRONIC), Issue 5 2006W. Scott Howard This essay has four interconnected goals: 1) to reflect upon some of the major theoretical and methodological developments (since about 1950) in the fields of early modern literary studies and history vis-à-vis the question of historicism; 2) to address, within the context of seventeenth-century England, inter-relationships between poetics and historiography; 3) to examine that "interdisciplinarity" specifically in terms of the seventeenth-century English poetic elegy; and 4) to trace (from Plato to Puttenham) and to argue for a specific theoretical aspect of that inter-relationship, which I will call historical figuration. My argument will hinge upon these connecting points, especially the latter two. On the one hand, I will argue that an early modern paradigm shift from theocentric to increasingly secular narrative frameworks for personal and national histories contributes to a transformation in poetic genre. English poets began to formulate a new intra-textual crisis of linguistic signification within the elegy's construction of loss and spiritual consolation as the experience of death and mourning became less theocentric and communal and more secular and individualized during the seventeenth century. This new intra-textuality to elegiac resistance emerges gradually but consistently from approximately the 1620s onward, facilitating the genre's new articulations of consolation situated within and against historical contexts rather than projected toward a transcendental horizon. On the other hand, I will also argue that this distinctive inter-relationship between poetics and historiography may be theorized as historical figuration, which may be linked directly to key contributions to the history of poetic theory from Plato to Puttenham. My two-fold thesis thus attempts to engender and engage what some may see as a trans-discursive poetics of culture. However, I would hesitate to place my argument within the new-historicist camp, but would hope instead that this essay may contribute to the emerging, interdisciplinary sub-field of new genre studies, which seeks to examine literary genres as manifestations of aesthetic forms and social discourses. [source] Facilitating process control teaching and learning in a virtual laboratory environmentCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 2 2002T. Murphy Abstract The rapid pace of technological developments and the high cost of engineering equipment, pose several challenges to traditional modes of engineering education. Innovations in education are desirable. In particular, education on practical aspects of engineering and personnel training can be enhanced through the use of virtual laboratories. Such educative experiences allow a student to better understand the theoretical aspects of the discipline in addition to its integration with practical knowledge. In this work, the development, set-up and application of a virtual twin heat exchanger plant is described. The philosophy and methodology of our approach is described, including the implementation details and our experience in using it. The effectiveness of the platform in educating students and in training industrial personnel is described. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 10: 79,87, 2002; Published online in Wiley InterScience (www.interscience.wiley.com.); DOI 10.1002/cae.10011 [source] Hapten,protein binding: from theory to practical application in the in vitro prediction of skin sensitizationCONTACT DERMATITIS, Issue 4 2005Maja Divkovic In view of the forthcoming European Union ban on in vivo testing of cosmetic and toiletry ingredients, following the publication of the 7th amendment to the Cosmetics Directive, the search for practical, alternative, non-animal approaches is gathering pace. For the end-point of skin sensitization, the ultimate goal, i.e. the development and validation of alternative in vitro/in silico assays by 2013, may be achieved through a better understanding of the skin sensitization process on the cellular and molecular levels. One of the key molecular events in skin sensitization is protein haptenation, i.e. the chemical modification of self-skin protein(s) thus forming macromolecular immunogens. This concept is widely accepted and in theory can be used to explain the sensitizing capacity of many known skin sensitizers. Thus, the principle of protein or peptide haptenation could be used in in vitro assays to predict the sensitization potential of a new chemical entity. In this review, we consider some of the theoretical aspects of protein haptenation, how mechanisms of protein haptenation can be investigated experimentally and how we can use such knowledge in the development of novel, alternative approaches for predicting skin sensitization potential in the future. [source] Computer-assisted 2-D agarose electrophoresis of Haemophilus influenzae type B meningitis vaccines and analysis of polydisperse particle populations in the size range of viruses: A reviewELECTROPHORESIS, Issue 4 2007Dietmar Tietz Dr. Abstract When protein,polysaccharide conjugated vaccines were first developed for the immunization of small children against meningitis caused by infection with Haemophilus influenzae type b (Hib), the vaccine preparations varied in immunogenicity. Testing for immunogenicity was time-consuming and alternative analytical procedures for determining vaccine quality were unsatisfactory. For example, due to the very high molecular weight of the vaccine particles, immunogens could only be physically characterized as a fraction in the void volume of Sepharose gel filtration. In search of better analytical methods, a computer-assisted electrophoretic technique for analyzing such vaccines was developed in the period from 1983 to 1995. This new approach made it possible to analyze highly negatively charged particles as large as or larger than intact viruses. 2-D gel patterns were generated that varied depending on the conditions of the particular vaccine preparation and were therefore characteristic of each vaccine sample. Thus, vaccine particle populations with a continuous size variation over a wide range (polydisperse) could be characterized according to size and free mobility (related to particle surface net charge density). These advances are reviewed in this article, since the developed methods are still a promising tool for vaccine quality control and for predicting immunogen effectiveness in the production of vaccines. The technique is potentially beneficial for Hib immunogens and other high-molecular-mass vaccines. Additional biomedical applications for this nondenaturing electrophoretic technique are briefly discussed and detailed information about computational and mathematical procedures and theoretical aspects is provided in the Appendices. [source] Beyond English Literature A Level: The silence of the seminar?ENGLISH IN EDUCATION, Issue 3 2009A study of an undergraduate literary theory seminar Abstract This paper presents data from a doctoral study of the relationships between A Level English Literature and university English, a study which examines the experiences of one class of first year university English students. It argues that, whilst the socio-cultural emphases of literary study in the university have the potential to offer a great deal to students, full attention to the interplay between curriculum and pedagogy, and an understanding of the values and assumptions which students and lecturers bring to the literature classroom, are vital if students are to be genuinely engaged in the theoretical aspects of the discipline. [source] Discussion on ,Personality psychology as a truly behavioural science' by R. Michael FurrEUROPEAN JOURNAL OF PERSONALITY, Issue 5 2009Article first published online: 14 JUL 200 Yes We Can! A Plea for Direct Behavioural Observation in Personality Research MITJA D. BACK and BORIS EGLOFF Department of Psychology, Johannes Gutenberg University Mainz, Germany mback@uni-leipzig.de Furr's target paper (this issue) is thought to enhance the standing of personality psychology as a truly behavioural science. We wholeheartedly agree with this goal. In our comment we argue for more specific and ambitious requirements for behavioural personality research. Specifically, we show why behaviour should be observed directly. Moreover, we illustratively describe potentially interesting approaches in behavioural personality research: lens model analyses, the observation of multiple behaviours in diverse experimentally created situations and the observation of behaviour in real life. Copyright © 2009 John Wiley & Sons, Ltd. The Categories of Behaviour Should be Clearly Defined PETER BORKENAU Department of Psychology, Martin-Luther University Halle-Wittenberg, Germany p.borkenau@psych.uni-halle.de The target paper is helpful by clarifying the terminology as well as the strengths and weaknesses of several approaches to collect behavioural data. Insufficiently considered, however, is the clarity of the categories being used for the coding of behaviour. Evidence is reported showing that interjudge agreement for retrospective and even concurrent codings of behaviour does not execeed interjudge agreement for personality traits if the categories being used for the coding of behaviour are not clearly defined. By contrast, if the behaviour to be registered is unambiguously defined, interjudge agreement may be almost perfect. Copyright © 2009 John Wiley & Sons, Ltd. Behaviour Functions in Personality Psychology PHILIP J. CORR Department of Psychology, Faculty of Social Sciences, University of East Anglia, Norwich, UK Philip.Corr@btopenworld.com Furr's target paper highlights the importance, yet under-representation, of behaviour in published articles in personality psychology. Whilst agreeing with most of his points, I remain unclear as to how behaviour (as specifically defined by Furr) relates to other forms of psychological data (e.g. cognitive task performance). In addition, it is not clear how the functions of behaviour are to be decided: different behaviours may serve the same function; and identical behaviours may serve different functions. To clarify these points, methodological and theoretical aspects of Furr's proposal would benefit from delineation. Copyright © 2009 John Wiley & Sons, Ltd. On the Difference Between Experience-Sampling Self-Reports and Other Self-Reports WILLIAM FLEESON Department of Psychology, Wake Forest University, Winston-Salem, NC, USA fleesonW@wfu.edu Furr's fair but evaluative consideration of the strengths and weaknesses of behavioural assessment methods is a great service to the field. As part of his consideration, Furr makes a subtle and sophisticated distinction between different self-report methods. It is easy to dismiss all self-reports as poor measures, because some are poor. In contrast, Furr points out that the immediacy of the self-reports of behaviour in experience-sampling make experience-sampling one of the three strongest methods for assessing behaviour. This comment supports his conclusion, by arguing that ESM greatly diminishes one the three major problems afflicting self-reports,lack of knowledge,and because direct observations also suffer from the other two major problems afflicting self-reports. Copyright © 2009 John Wiley & Sons, Ltd. What and Where is ,Behaviour' in Personality Psychology? LAURA A. KING and JASON TRENT Department of Psychology, University of Missouri, Columbia, USA kingla@missouri.edu Furr is to be lauded for presenting a coherent and persuasive case for the lack of behavioural data in personality psychology. While agreeing wholeheartedly that personality psychology could benefit from greater inclusion of behavioural variables, here we question two aspects of Furr's analysis, first his definition of behaviour and second, his evidence that behaviour is under-appreciated in personality psychology. Copyright © 2009 John Wiley & Sons, Ltd. Naturalistic Observation of Daily Behaviour in Personality Psychology MATTHIAS R. MEHL Department of Psychology, University of Arizona, Tucson, AZ, USA mehl@email.arizona.edu This comment highlights naturalistic observation as a specific method within Furr's (this issue) cluster direct behavioural observation and discusses the Electronically Activated Recorder (EAR) as a naturalistic observation sampling method that can be used in relatively large, nomothetic studies. Naturalistic observation with a method such as the EAR can inform researchers' understanding of personality in its relationship to daily behaviour in two important ways. It can help calibrate personality effects against act-frequencies of real-world behaviour and provide ecological, behavioural personality criteria that are independent of self-report. Copyright © 2009 John Wiley & Sons, Ltd. Measuring Behaviour D. S. MOSKOWITZ and JENNIFER J. RUSSELL Department of Psychology, McGill University, Montreal, Canada dsm@psych.mcgill.ca Furr (this issue) provides an illuminating comparison of the strengths and weaknesses of various methods for assessing behaviour. In the selection of a method for assessing behaviour, there should be a careful analysis of the definition of the behaviour and the purpose of assessment. This commentary clarifies and expands upon some points concerning the suitability of experience sampling measures, referred to as Intensive Repeated Measurements in Naturalistic Settings (IRM-NS). IRM-NS measures are particularly useful for constructing measures of differing levels of specificity or generality, for providing individual difference measures which can be associated with multiple layers of contextual variables, and for providing measures capable of reflecting variability and distributional features of behaviour. Copyright © 2009 John Wiley & Sons, Ltd. Behaviours, Non-Behaviours and Self-Reports SAMPO V. PAUNONEN Department of Psychology, University of Western Ontario, London, Canada paunonen@uwo.ca Furr's (this issue) thoughtful analysis of the contemporary body of research in personality psychology has led him to two conclusions: our science does not do enough to study real, observable behaviours; and, when it does, too often it relies on ,weak' methods based on retrospective self-reports of behaviour. In reply, I note that many researchers are interested in going beyond the study of individual behaviours to the behaviour trends embodied in personality traits; and the self-report of behaviour, using well-validated personality questionnaires, is often the best measurement option. Copyright © 2009 John Wiley & Sons, Ltd. An Ethological Perspective on How to Define and Study Behaviour LARS PENKE Department of Psychology, The University of Edinburgh, Edinburgh, UK lars.penke@ed.ac.uk While Furr (this issue) makes many important contributions to the study of behaviour, his definition of behaviour is somewhat questionable and also lacks a broader theoretical frame. I provide some historical and theoretical background on the study of behaviour in psychology and biology, from which I conclude that a general definition of behaviour might be out of reach. However, psychological research can gain from adding a functional perspective on behaviour in the tradition of Tinbergens's four questions, which takes long-term outcomes and fitness consequences of behaviours into account. Copyright © 2009 John Wiley & Sons, Ltd. What is a Behaviour? MARCO PERUGINI Faculty of Psychology, University of Milan,Bicocca, Milan, Italy marco.perugini@unimib.it The target paper proposes an interesting framework to classify behaviour as well as a convincing plea to use it more often in personality research. However, besides some potential issues in the definition of what is a behaviour, the application of the proposed definition to specific cases is at times inconsistent. I argue that this is because Furr attempts to provide a theory-free definition yet he implicitly uses theoretical considerations when applying the definition to specific cases. Copyright © 2009 John Wiley & Sons, Ltd. Is Personality Really the Study of Behaviour? MICHAEL D. ROBINSON Department of Psychology, North Dakota State University, Fargo, ND, USA Michael.D.Robinson@ndsu.edu Furr (this issue) contends that behavioural studies of personality are particularly important, have been under-appreciated, and should be privileged in the future. The present commentary instead suggests that personality psychology has more value as an integrative science rather than one that narrowly pursues a behavioural agenda. Cognition, emotion, motivation, the self-concept and the structure of personality are important topics regardless of their possible links to behaviour. Indeed, the ultimate goal of personality psychology is to understanding individual difference functioning broadly considered rather than behaviour narrowly considered. Copyright © 2009 John Wiley & Sons, Ltd. Linking Personality and Behaviour Based on Theory MANFRED SCHMITT Department of Psychology, University of Koblenz-Landau, Landau, Germany schmittm@uni-landau.de My comments on Furr's (this issue) target paper ,Personality as a Truly Behavioural Science' are meant to complement his behavioural taxonomy and sharpen some of the presumptions and conclusions of his analysis. First, I argue that the relevance of behaviour for our field depends on how we define personality. Second, I propose that every taxonomy of behaviour should be grounded in theory. The quality of behavioural data does not only depend on the validity of the measures we use. It also depends on how well behavioural data reflect theoretical assumptions on the causal factors and mechanisms that shape behaviour. Third, I suggest that the quality of personality theories, personality research and behavioural data will profit from ideas about the psychological processes and mechanisms that link personality and behaviour. Copyright © 2009 John Wiley & Sons, Ltd. The Apparent Objectivity of Behaviour is Illusory RYNE A. SHERMAN, CHRISTOPHER S. NAVE and DAVID C. FUNDER Department of Psychology, University of California, Riverside, CA, USA funder@ucr.edu It is often presumed that objective measures of behaviour (e.g. counts of the number of smiles) are more scientific than more subjective measures of behaviour (e.g. ratings of the degree to which a person behaved in a cheerful manner). We contend that the apparent objectivity of any behavioural measure is illusory. First, the reliability of more subjective measures of behaviour is often strikingly similar to the reliabilities of so-called objective measures. Further, a growing body of literature suggests that subjective measures of behaviour provide more valid measures of psychological constructs of interest. Copyright © 2009 John Wiley & Sons, Ltd. Personality and Behaviour: A Neglected Opportunity? LIAD UZIEL and ROY F. BAUMEISTER Department of Psychology, Florida State University, Tallahassee, FL, USA Baumeister@psy.fsu.edu Personality psychology has neglected the study of behaviour. Furr's efforts to provide a stricter definition of behaviour will not solve the problem, although they may be helpful in other ways. His articulation of various research strategies for studying behaviour will be more helpful for enabling personality psychology to contribute important insights and principles about behaviour. The neglect of behaviour may have roots in how personality psychologists define the mission of their field, but expanding that mission to encompass behaviour would be a positive step. Copyright © 2009 John Wiley & Sons, Ltd. [source] Some remarks concerning the measurement of the ferromagnetic losses under non-sinusoidal conditionsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 2 2002Andrei, ugulea The present standards concerning the measurement of the losses in ferromagnetic media, namely the IEC publications 404-2 (1978), 404-;3 (1982) and 404,10 (1988), refer only to the magnetic flux densities between 1 T and 1.85 T, if the magnetic sheets are grain oriented, and 1 T and 1.5 T if the magnetic sheets are nonoriented. The time variation of the magnetic fluxes must be almost sinusoidal at industrial frequencies of 50 Hz or 60 Hz and medium frequencies between 400 Hz and 10,000 Hz. In the above-mentioned standards there are no references concerning the measurement of losses under non-sinusoidal conditions. The paper deals with some theoretical aspects concerning the power-flows under non-sinusoidal time variation of the electromagnetic fields. The theoretical conclusions are applied to the study of the losses in ferromagnetic media. It is shown that new norms or standards are necessary. Some practical suggestions are given at the end. [source] Multiaxial fatigue of rubber: Part I: equivalence criteria and theoretical aspectsFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 6 2005W. V. MARS ABSTRACT This paper investigates commonly used approaches for fatigue crack nucleation analysis in rubber, including maximum principal strain (or stretch), strain energy density and octahedral shear strain criteria. The ability of these traditional equivalence criteria, as well as a recent equivalence criterion (the cracking energy density) to predict multiaxial fatigue behaviour is explored. Theoretical considerations are also introduced relating to the applicability of various fatigue life analysis approaches. These include the scalar nature of traditional equivalence criteria, robustness of the criteria investigated for a wide range of multiaxial loadings, effects of crack closure and applications to non-proportional multiaxial loadings. It is shown that the notion of a stress or strain amplitude tensor used for the analysis of multiaxial loading in metals is not appropriate in the analysis of rubber due to nonlinearity associated with finite strains and near incompressibility. Taken together, these considerations illustrate that traditional criteria are not sufficiently consistent or complete to permit confident analysis of arbitrary multiaxial loading histories, and that an analysis approach specific to the failure plane is needed. Of the three traditional criteria, maximum principal strain is shown to match most closely to the cracking energy density criterion, in terms of a failure locus in principal stretch space. [source] Future Directions for the Teaching and Learning of Statistics at the Tertiary LevelINTERNATIONAL STATISTICAL REVIEW, Issue 1 2001Des F. Nicholl Summary Significant advances in, and the resultant impact of, Information Technology (IT) during the last fifteen years has resulted in a much more data based society, a trend that can be expected to continue into the foreseeable future. This phenomenon has had a real impact on the Statistics discipline and will continue to result in changes in both content and course delivery. Major research directions have also evolved during the last ten years directly as a result of advances in IT. The impact of these advances has started to flow into course content, at least for advanced courses. One question which arises relates to what impact will this have on the future training of statisticians, both with respect to course content and mode of delivery. At the tertiary level the last 40 years has seen significant advances in theoretical aspects of the Statistics discipline. Universities have been outstanding at producing scholars with a strong theoretical background but questions have been asked as to whether this has, to some degree, been at the expense of appropriate training of the users of statistics (the ,tradespersons'). Future directions in the teaching and learning of Statistics must take into account the impact of IT together with the competing need to produce scholars as well as competent users of statistics to meet the future needs of the market place. For Statistics to survive as a recognizable discipline the need to be able to train statisticians with an ability to communicate is also seen as an areà of crucial importance. Satisfying the needs of society as well as meeting the needs of the profession are considered as the basic determinants which will derive the future teaching and training of statisticians at the tertiary level and will form the basis of this presentation. [source] Brain, mind, and dyadic change processesJOURNAL OF CLINICAL PSYCHOLOGY, Issue 5 2006Robert J. Neborsky For many individuals attachment trauma is at the core of psychoneurosis and personality disorder. Combining theoretical aspects of psychodynamic therapy, developmental neuroscience, and attachment styles provides a useful framework for intensifying emotion and accelerating the course of treatment. A bihemispheric model is considered. The model addresses the challenge in treating the implicit trauma, which resides in the right hemisphere. This is achieved without resorting to interpretation, which is largely a left hemispheric process. The article presents a patient who benefits from a brief emotionally based psychotherapy that was completed after a course of a 20-year psychoanalysis. © 2006 Wiley Periodicals, Inc. J Clin Psychol: In Session 62: 523,538, 2006. [source] Satellite species in lampreys: a worldwide trend for ecological speciation in sympatry?JOURNAL OF FISH BIOLOGY, Issue 2 2003V. Salewski Amongst several theories of speciation, sympatric speciation has been the most controversial but it is now widely accepted that populations can become reproductively isolated without being separated geographically. One problem with the acceptance of the theory of sympatric speciation, however, has been the lack of supporting empirical data and it is still believed that geographical isolation is responsible for the majority of speciation events. Here the example of species pairs in lampreys suggests that sympatric speciation in a whole taxonomic group could occur throughout its worldwide range. Lampreys occur in two ecologically distinct forms: parasitic mostly anadromous species that forage on tissue and body fluids of host fishes, and non-parasitic forms that, apart from a short adult life when they cease feeding, spend their entire life as filter feeders in the substratum of stream beds. Both forms occur in sympatric species pairs throughout the range of lampreys that occur in Eurasia, North America and Australia and it is widely acknowledged that non-parasitic forms derive from parasitic forms. The larvae of both forms can be distinguished by their potential fecundity and therefore, it is argued that the mode of life is not a consequence of different ecological conditions. Furthermore, as lampreys prefer to choose mates of similar sizes and fertilization success decreases with increasing difference in body size, there is a strong disruptive selection between the two forms and they are therefore reproductively isolated. Besides theoretical aspects, the similarity of the species pairs, together with their occurrence in sympatry, the occurrence of forms with intermediate characteristics, and examples where speciation might be in progress, hints at the possibility that speciation also occurred in sympatry. The difference between lampreys and other examples of sympatric speciation is that there seems to be a trend towards sympatric speciation events throughout the worldwide range of lampreys which is neither restricted to relatively small localities nor caused by human disturbance. Species pairs in lampreys therefore offer a unique possibility of studying the process of sympatric speciation on a large scale. [source] Hyperbranched cyclic and multicyclic polymers by "a2+b4" polycondensationsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2009Hans R. Kricheldorf Abstract At first, theoretical aspects of "a2+b4" polycondensations (meaning polycondensations of difunctional and tetrafunctional monomers) are discussed and compared with what is known about "a2+b3" polycondensations. The following review of experimental results is subdivided into three sections. First, syntheses of hyperbranched polyethers and polyesters by polycondensations based on equimolar feed ratios will be reported. Second, kinetically controlled (i.e., irreversible) syntheses of multicyclic polymers using equifunctional feed ratios (i.e., a2/b4 ratios of 2:1) will be described. In the third section, syntheses of multicyclic polymers via thermodynamically controlled (reversible) "a2+b4" polycondensations will be discussed. Characteristic for these polycondensations are again equifunctional feed ratios and metal alkoxides as "a2" or "b4" monomers, which catalyze rapid equilibration reactions. Finally, potential applications of the new polymers will shortly be mentioned. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1971,1987, 2009 [source] Comprehensive two-dimensional gas chromatography-mass spectrometry: A reviewMASS SPECTROMETRY REVIEWS, Issue 2 2008Luigi Mondello Abstract Although comprehensive two-dimensional gas chromatography (GC,×,GC) has been on the scene for more than 15 years, it is still generally considered a relatively novel technique and is yet far from being fully established. The revolutionary aspect of GC,×,GC, with respect to classical multidimensional chromatography, is that the entire sample is subjected to two distinct analytical separations. The resulting enhanced separating capacity makes this approach a prime choice when GC analysts are challenged with highly complex mixtures. The combination of a third mass spectrometric dimension to a GC,×,GC system generates the most powerful analytical tool today for volatile and semi-volatile analytes. The present review is focused on the rather brief, but not scant, history of comprehensive two-dimensional GC-MS: the first experiments were carried out at the end of the 1990s and, since then, the methodology has been increasingly studied and applied. Almost all GC,×,GC-MS applications have been carried out by using either a time-of-flight or quadrupole mass analyzer; significant experiments relative to a variety of research fields, as well as advantages and disadvantages of the MS systems employed, are discussed. The principles, practical and theoretical aspects, and the most significant developments of GC,×,GC are also described. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 27:101,124, 2008 [source] Convergence analysis of the streamline diffusion and discontinuous Galerkin methods for the Vlasov-Fokker-Planck systemNUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS, Issue 3 2005M. Asadzadeh Abstract We prove stability estimates and derive optimal convergence rates for the streamline diffusion and discontinuous Galerkin finite element methods for discretization of the multi-dimensional Vlasov-Fokker-Planck system. The focus is on the theoretical aspects, where we deal with construction and convergence analysis of the discretization schemes. Some related special cases are implemented in M. Asadzadeh [Appl Comput Meth 1(2) (2002), 158,175] and M. Asadzadeh and A. Sopasakis [Comput Meth Appl Mech Eng 191(41,42) (2002), 4641,4661]. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2005 [source] On the solution of an initial-boundary value problem that combines Neumann and integral condition for the wave equation,NUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS, Issue 1 2005Mehdi Dehghan Abstract Numerical solution of hyperbolic partial differential equation with an integral condition continues to be a major research area with widespread applications in modern physics and technology. Many physical phenomena are modeled by nonclassical hyperbolic boundary value problems with nonlocal boundary conditions. In place of the classical specification of boundary data, we impose a nonlocal boundary condition. Partial differential equations with nonlocal boundary specifications have received much attention in last 20 years. However, most of the articles were directed to the second-order parabolic equation, particularly to heat conduction equation. We will deal here with new type of nonlocal boundary value problem that is the solution of hyperbolic partial differential equations with nonlocal boundary specifications. These nonlocal conditions arise mainly when the data on the boundary can not be measured directly. Several finite difference methods have been proposed for the numerical solution of this one-dimensional nonclassic boundary value problem. These computational techniques are compared using the largest error terms in the resulting modified equivalent partial differential equation. Numerical results supporting theoretical expectations are given. Restrictions on using higher order computational techniques for the studied problem are discussed. Suitable references on various physical applications and the theoretical aspects of solutions are introduced at the end of this article. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2005 [source] Analysis of the vacuum infusion molding processPOLYMER COMPOSITES, Issue 1 2000A. Hammami The vacuum infusion molding process is becoming increasingly popular for the production of large composite parts. A comprehensive model of the process has not been proposed yet, making its optimization difficult. The flexible nature of the vacuum bag coupled to the varying pressure inside the mold cavity results in a variation of the cavity thickness during the impregnation. A complete simulation model must incorporate this phenomenon. In this paper, a complete analysis of the vacuum infusion molding process is presented. The analysis is not restricted to the theoretical aspects but also reviews the effect of the main processing parameters. The parameters investigated in this paper are thought to be those of most interest for the process, i.e. the compaction of the reinforcement, the permeability, the infusion strategy and the presence of flow enhancement layers. Following the characterization experiments, a 1-D model for the vacuum infusion molding process is presented. This model is derived assuming that an elastic equlibrium holds in the mold cavity during mold filling. Even though good agreement was found between simulation results and experiments, it is concluded that additional work is needed on the numerical model to integrate interesting findings from the experimental part. [source] Carrying out an optimal experimentACTA CRYSTALLOGRAPHICA SECTION D, Issue 4 2010Zbigniew Dauter Diffraction data collection is the last experimental stage in structural crystallography. It has several technical and theoretical aspects and a compromise usually has to be found between various parameters in order to achieve optimal data quality. The influence and importance of various experimental parameters and their consequences are discussed in the context of different data applications, such as molecular replacement, anomalous phasing, high-resolution refinement or searching for ligands. [source] Closed-form approximations to the error and complementary error functions and their applications in atmospheric scienceATMOSPHERIC SCIENCE LETTERS, Issue 3 2007C. Ren Abstract The error function, as well as related functions, occurs in theoretical aspects of many parts of atmospheric science. This note presents a closed-form approximation for the error, complementary error, and scaled complementary error functions, with maximum relative errors within 0.8%. Unlike other approximate solutions, this single equation gives answers within the stated accuracy for real variable x , [0,). The approximation is very useful in solving atmospheric science problems by providing analytical solutions. Examples of the utility of the approximation are: the computation of cirrus cloud physics inside a general circulation model, the cumulative distribution functions of normal and log-normal distributions, and the recurrence period for risk assessment. Copyright © 2007 Royal Meteorological Society [source] Short wavelength automated perimetryACTA OPHTHALMOLOGICA, Issue 6 2001John M. Wild ABSTRACT. Short Wavelength Automated Perimetry (SWAP) utilizes a blue stimulus to preferentially stimulate the blue cones and a high luminance yellow background to adapt the green and red cones and to saturate, simultaneously, the activity of the rods. This review describes the theoretical aspects of SWAP, highlights current limitations associated with the technique and discusses potential clinical applications. Compared to white-on-white (W-W) perimetry, SWAP is limited clinically by: greater variability associated with the estimation of threshold, ocular media absorption, increased examination duration and an additional learning effect. Comparative studies of SWAP and W-W perimetry have generally been undertaken on small cohorts of patients. The conclusions are frequently unconvincing due to limitations for SWAP in the delineation of abnormality and of progressive field loss. SWAP is almost certainly able to identify glaucomatous visual field loss in advance of that by W-W perimetry although the incidence of progressive field loss is similar between the two techniques. Increasing evidence suggests that functional abnormality with SWAP is preceded by structural abnormality of the optic nerve head and/or the retinal nerve fibre layer. SWAP appears to be beneficial in the detection of diabetic macular oedema and possibly in some neuro-ophthalmic disorders. [source] | |||||||||||||||||||||||||||||||