Moral wrongs, disadvantages, and disability: a critique of critical disability studies

Critical disability studies (CDS) has emerged as an approach to the study of disability over the last decade or so and has sought to present a challenge to the predominantly materialist line found in the more conventional disability studies approaches. In much the same way that the original development of the social model resulted in a necessary correction to the overly individualized accounts of disability that prevailed in much of the interpretive accounts which then dominated medical sociology, so too has CDS challenged the materialist line of disability studies. In this paper we review the ideas behind this development and analyse and critique some of its key ideas. The paper starts with a brief overview of the main theorists and approaches contained within CDS and then moves on to normative issues; namely, to the ethical and political applicability of CDS

Behaviour change techniques taxonomy v1: Feedback to inform the development of an ontology [version 2; peer review: 2 approved]

Background: To build cumulative evidence about what works in behaviour change interventions, efforts have been made to develop classification systems for specifying the content of interventions. The Behaviour Change Techniques (BCT) Taxonomy v1 (BCTTv1) is one of the most widely used classifications of behaviour change techniques across a variety of behaviours. The BCTTv1 was intentionally named version 1 to allow for further revisions to the taxonomy. This study aimed to gather data to improve the BCTTv1 and provide recommendations for developing it into a more elaborated knowledge structure, an ontology. Methods: Feedback from users of BCTTv1 about limitations and proposed improvements was collected through the BCT website, user survey, researchers and experts involved in the Human Behaviour-Change Project, and a consultation. In addition, relevant published research reports and other classification systems of BCTs were analysed. These data were synthesised to produce recommendations to inform the development of an ontology of BCTs. Results: A total of 282 comments from six sources were reviewed and synthesised into four categories of suggestions: additional BCTs, amendments to labels and definitions of specific BCTs, amendments to the groupings, and general improvements. Feedback suggested some lack of clarity regarding understanding and identifying techniques from labels, definitions, and examples; distinctions and relations between BCTs; and knowing what they would look like in practice. Three recommendations to improve the BCTTv1 resulted from this analysis: to review the label and definition of each BCT, the 16 groupings of BCTs, and the examples illustrating BCTs. Conclusions : This review of feedback about BCTTv1 identified the need to improve the precision and knowledge structure of the current taxonomy. A BCT ontology would enable the specification of relationships between BCTs, more precise definitions, and allow better interoperability with other ontologies. This ontology will be developed as part of the Human Behaviour-Change Project

Behaviour change techniques taxonomy v1: Feedback to inform the development of an ontology

Background: To build cumulative evidence about what works in behaviour change interventions, efforts have been made to develop classification systems for specifying the content of interventions. The Behaviour Change Techniques (BCT) Taxonomy v1 (BCTTv1) is one of the most widely used classifications of behaviour change techniques across a variety of behaviours. The BCTTv1 was intentionally named version 1 to allow for further revisions to the taxonomy. This study aimed to gather data to inform the development of BCTTv1 into a more elaborated knowledge structure, an ontology. Methods: Feedback from users of BCTTv1 about limitations and proposed improvements was collected through the BCT website, a user survey, researchers and experts involved in the Human Behaviour Change Project, and a consultation. In addition, relevant published research reports and other classification systems of BCTs were analysed. These data were synthesised to produce recommendations to inform the development of an ontology of BCTs. Results: A total of 282 comments from six sources were reviewed and synthesised into four categories of suggestions: additional BCTs, amendments to labels and definitions of specific BCTs, amendments to the groupings, and general improvements. Feedback suggested some lack of clarity regarding understanding and identifying techniques from labels, definitions, and examples; distinctions and relations between BCTs; and knowing what they would look like in practice. Three recommendations resulted from this analysis: to review the label and definition of each BCT, the 16 groupings of BCTs, and the examples illustrating BCTs. Conclusions: This review of feedback about BCTTv1 identified the need to improve the precision and knowledge structure of the current taxonomy. A BCT ontology would enable the specification of relationships between BCTs, more precise definitions, and allow better interoperability with other ontologies. This ontology will be developed as part of the Human Behaviour Change Project

Origin of the high piezoelectric response in PbZr(1-x)TixO3

High resolution x-ray powder diffraction measurements on poled PbZr(1-x)TixO3 (PZT) ceramic samples close to the rhombohedral-tetragonal phase boundary (the so-called morphotropic phase boundary, MPB) have shown that for both rhombohedral and tetragonal compositions, the piezoelectric elongation of the unit cell does not occur along the polar directions but along those directions associated with the monoclinic distortion. This work provides the first direct evidence for the origin of the very high piezoelectricity in PZT.Comment: 4 pages, 4 EPS figures embedded. More specific title and abstract. To appear in Phys. Rev. Let

A Raman Study of Morphotropic Phase Boundary in PbZr1-xTixO3 at low temperatures

Raman spectra of PbZr1-xTixO3 ceramics with titanium concentration varying between 0.40 and 0.60 were measured at 7 K. By observing the concentration-frequency dependence of vibrational modes, we identified the boundaries among rhombohedral, monoclinic, and tetragonal ferroelectric phases. The analysis of the spectra was made in the view of theory group analysis making possible the assignment of some modes for the monoclinic phase.Comment: 5 pages, 4 figure

Phase diagram of the ferroelectric-relaxor (1-x)PbMg(1/3)Nb(2/3)O3-xPbTiO3

Synchrotron x-ray powder diffraction measurements have been performed on unpoled ceramic samples of (1-x)PbMg(1/3)Nb(2/3)O3-xPbTiO3 (PMN-xPT) with 30%<= x<= 39% as a function of temperature around the morphotropic phase boundary (MPB), which is the line separating the rhombohedral and tetragonal phases in the phase diagram. The experiments have revealed very interesting features previously unknown in this or related systems. The sharp and well-defined diffraction profiles observed at high and intermediate temperatures in the cubic and tetragonal phases, respectively, are in contrast to the broad features encountered at low temperatures. These peculiar characteristics, which are associated with the monoclinic phase of MC-type previously reported by Kiat et al and Singh et al., can only be interpreted as multiple coexisting structures with MC as the major component. An analysis of the diffraction profiles has allowed us to properly characterize the PMN-xPT phase diagram and to determine the stability region of the monoclinic phase, which extends from x= 31% to x= 37% at 20 K. The complex lansdcape of observed phases points to an energy balance between the different PMN-xPT phases which is intrinsically much more delicate than that of related systems such as PbZr(1-x)TixO3 or (1-x)PbZn(1/3)Nb(1/3)O3-xPbTiO3. These observations are in good accord with an optical study of x= 33% by Xu et al., who observed monoclinic domains with several different polar directions coexisting with rhombohedral domains, in the same single crystal.Comment: REVTeX4, 11 pages, 10 figures embedde

A tetragonal-to-monoclinic phase transition in a ferroelectric perovskite: the structure of PbZr(0.52)Ti(0.48)O3

The perovskite-like ferroelectric system PbZr(1-x)Ti(x)O3 (PZT) has a nearly vertical morphotropic phase boundary (MPB) around x=0.45-0.50. Recent synchrotron x-ray powder diffraction measurements by Noheda et al. [Appl. Phys. Lett. 74, 2059 (1999)] have revealed a new monoclinic phase between the previously-established tetragonal and rhombohedral regions. In the present work we describe a Rietveld analysis of the detailed structure of the tetragonal and monoclinic PZT phases on a sample with x= 0.48 for which the lattice parameters are respectively: at= 4.044 A, ct= 4.138 A, at 325 K, and am= 5.721 A, bm= 5.708 A, cm= 4.138 A, beta= 90.496 deg., at 20K. In the tetragonal phase the shifts of the atoms along the polar [001] direction are similar to those in PbTiO3 but the refinement indicates that there are, in addition, local disordered shifts of the Pb atoms of ~0.2 A perpendicular to the polar axis.. The monoclinic structure can be viewed as a condensation along one of the directions of the local displacements present in the tetragonal phase. It equally well corresponds to a freezing-out of the local displacements along one of the directions recently reported by Corker et al.[J. Phys. Condens. Matter 10, 6251 (1998)] for rhombohedral PZT. The monoclinic structure therefore provides a microscopic picture of the MPB region in which one of the "locally" monoclinic phases in the "average" rhombohedral or tetragonal structures freezes out, and thus represents a bridge between these two phases.Comment: REVTeX, 7 figures. Modifications after referee's suggestion: new figure (figure 5), comments in 2nd para. (Sect.III) and in 2nd & 3rd para. (Sect. IV-a), in the abstract: "...of ~0.2 A perpendicular to the polar axis.