433 resultados para Imaging science
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This chapter focuses on two challenges to science teachers knowledge that Fensham identifies as having recently emergedone a challenge from beyond Science and the other a challenge from within Science. Both challenges stem from common features of contemporary society, namely, its complexity and uncertainty. Both also confront science teachers with teaching situations that contrast markedly with the simplicity and certainty that have been characteristic of most school science education, and hence both present new demands for science teachers knowledge and skill. The first, the challenge from without Science, comes from the new world of work and the knowledge society. Regardless of their success in traditional school learning, many young persons in many modern economies are now seen as lacking other knowledge and skills that are essential for their personal, social and economic life. The second, the challenge from within Science, derives from changing notions of the nature of science itself. If the complexity and uncertainty of the knowledge society demand new understandings and contributions from science teachers, these are certainly matched by the demands that are posed by the role of complexity and uncertainty in science itself.
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A review of "Progressing science education: constructing the scientific research programme into the contingent nature of learning science", by Keith S. Taber, Dordrecht, Springer, 2009.
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This paper proposes a new research method, Participatory Action Design Research (PADR), for studies in the Urban Informatics domain. PADR supports Urban Informatics research in developing new technological means (e.g. using mobile and ubiquitous computing) to resolve contemporary issues or support everyday life in urban environments. The paper discusses the nature, aims and inherent methodological needs of Urban Informatics research, and proposes PADR as a method to address these needs. Situated in a socio-technical context, Urban Informatics requires a close dialogue between social and design-oriented fields of research as well as their methods. PADR combines Action Research and Design Science Research, both of which are used in Information Systems, another field with a strong socio-technical emphasis, and further adapts them to the cross-disciplinary needs and research context of Urban Informatics.
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Twin studies offer the opportunity to determine the relative contribution of genes versus environment in traits of interest. Here, we investigate the extent to which variance in brain structure is reduced in monozygous twins with identical genetic make-up. We investigate whether using twins as compared to a control population reduces variability in a number of common magnetic resonance (MR) structural measures, and we investigate the location of areas under major genetic influences. This is fundamental to understanding the benefit of using twins in studies where structure is the phenotype of interest. Twenty-three pairs of healthy MZ twins were compared to matched control pairs. Volume, T2 and diffusion MR imaging were performed as well as spectroscopy (MRS). Images were compared using (i) global measures of standard deviation and effect size, (ii) voxel-based analysis of similarity and (iii) intra-pair correlation. Global measures indicated a consistent increase in structural similarity in twins. The voxel-based and correlation analyses indicated a widespread pattern of increased similarity in twin pairs, particularly in frontal and temporal regions. The areas of increased similarity were most widespread for the diffusion trace and least widespread for T2. MRS showed consistent reduction in metabolite variation that was significant in the temporal lobe N-acetylaspartate (NAA). This study has shown the distribution and magnitude of reduced variability in brain volume, diffusion, T2 and metabolites in twins. The data suggest that evaluation of twins discordant for disease is indeed a valid way to attribute genetic or environmental influences to observed abnormalities in patients since evidence is provided for the underlying assumption of decreased variability in twins.
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OBJECTIVE: Childhood-onset type 1 diabetes is associated with neurocognitive deficits, but there is limited evidence to date regarding associated neuroanatomical brain changes and their relationship to illness variables such as age at disease onset. This report examines age-related changes in volume and T2 relaxation time (a fundamental parameter of magnetic resonance imaging that reflects tissue health) across the whole brain. RESEARCH DESIGN AND METHODS: Type 1 diabetes, N = 79 (mean age 20.32 4.24 years), and healthy control participants, N = 50 (mean age 20.53 3.60 years). There were no substantial group differences on socioeconomic status, sex ratio, or intelligence quotient. RESULTS: Regression analyses revealed a negative correlation between age and brain changes, with decreasing gray matter volume and T2 relaxation time with age in multiple brain regions in the type 1 diabetes group. In comparison, the age-related decline in the control group was small. Examination of the interaction of group and age confirmed a group difference (type 1 diabetes vs. control) in the relationship between age and brain volume/T2 relaxation time. CONCLUSIONS: We demonstrated an interaction between age and group in predicting brain volumes and T2 relaxation time such that there was a decline in these outcomes in type 1 diabetic participants that was much less evident in control subjects. Findings suggest the neurodevelopmental pathways of youth with type 1 diabetes have diverged from those of their healthy peers by late adolescence and early adulthood but the explanation for this phenomenon remains to be clarified.
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In this paper I consider a role for risk understanding in school science education. Grounds for this are described in terms of current sociological analyses of the contemporary world as a risk society and recent public understanding of science studies where science and risk are concerns commonly linked within the wider community. These concerns connect with support amongst many science educators for the goal of science education for citizenship. From this perspective scientific literacy for decision making on contemporary socioscientific issues is central. I argue that in such decision making risk understanding has an important role to play. I examine some of the challenges its inclusion in school science presents to science teachers, review previous writing about risk in the science education literature and consider how knowledge about risk might be addressed in school science. I also outline the varying conceptions of risk and suggest some future research directions which would support the inclusion of risk in classroom discussions of socioscientific issues.
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This paper reports one aspect of a study of 28 young adults (1826 years) engaging with the uncertain (contested) science of a television news report about recent research into mobile phone health risks. The aim of the study was to examine these young peoples accounts of scientific knowledge in this context. Seven groups of friends responded to the news report, initially in focus group discussions. Later in semi-structured interviews they elaborated their understanding of the nature of science through their explanations of the scientists disagreement and described their mobile phone safety risk assessments. This paper presents their accounts in terms of their views of the nature of science and their concept understanding. Discussions were audio-recorded then analysed by coding the talk in terms of issues raised, which were grouped into themes and interpreted in terms of a moderate social constructionist theoretical framing. In this context, most participants expressed a common sense view of the nature of science, describing it as an atheoretical, technical procedure of scientists testing their personal opinions on the issue, subject to the influence of funding sponsors. The roles of theory and data interpretation were largely ignored. It is argued that the nature of science understanding is crucial to engagement with contemporary socioscientific issues, particularly the roles of argumentation, theory, data interpretation, and the distinction of science from common sense. Implications for school science relate primarily to nature of science teaching and the inclusion of socioscientific issues in school science curricula. Future research directions are considered.
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The accuracy of marker placement on palpable surface anatomical landmarks is an important consideration in biomechanics. Although marker placement reliability has been studied in some depth, it remains unclear whether or not the markers are accurately positioned over the intended landmark in order to define the static position and orientation of the segment. A novel method using commonly available X-ray imaging was developed to identify the accuracy of markers placed on the shoe surface by palpating landmarks through the shoe. An anteriorposterior and lateralmedial X-ray was taken on 24 participants with a newly developed marker set applied to both the skin and shoe. The vector magnitude of both skin- and shoe-mounted markers from the anatomical landmark was calculated, as well as the mean marker offset between skin- and shoe-mounted markers. The accuracy of placing markers on the shoe relative to the skin-mounted markers, accounting for shoe thickness, was less than 5mm for all markers studied. Further, when using the developed guidelines provided in this study, the method was deemed reliable (Intra-rater ICCs0.500.92). In conclusion, the method proposed here can reliably assess marker placement accuracy on the shoe surface relative to chosen anatomical landmarks beneath the skin.
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The surface amorphous layer of articular cartilage is of primary importance to its load-bearing and lubrication function. This lipid-filled layer is degraded/disrupted or eliminated when cartilage degenerates due to diseases. This article examines further the characteristic of this surface overlay using a combination of microscopy and imaging methods to evaluate the hypothesis that the surface of articular cartilage can be repaired by exposing degraded cartilage to aqueous synthetic lipid mixtures. The preliminary results demonstrate that it is possible to create a new surface layer of phospholipids on the surface of cartilage following artificial lipid removal, but such a layer does not possess enough mechanical strength for physiological function when created with either unsaturated palmitoyloleoyl- phosphatidylcholine or saturated dipalmitoyl-phosphatidylcholine component of joint lipid composition alone. We conclude that this may be due to low structural cohesivity, inadequate time of exposure, and the mix/content of lipid in the incubation environment.
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Magnetic Resonance Imaging was used to study changes in the crystalline lens and ciliary body with accommodation and aging. Monocular images were obtained in 15 young (19-29 years) and 15 older (60-70 years) emmetropes when viewing at far (6m) and at individual near points (14.5 to 20.9 cm) in the younger group. With accommodation, lens thickness increased (mean95% CI: 0.330.06mm) by a similar magnitude to the decrease in anterior chamber depth (0.310.07mm) and equatorial diameter (0.320.04mm) with a decrease in the radius of curvature of the posterior lens surface (0.580.30mm). Anterior lens surface shape could not be determined due to the overlapping region with the iris. Ciliary ring diameter decreased (0.440.17mm) with no decrease in circumlental space or forward ciliary body movement. With aging, lens thickness increased (mean95% CI: 0.970.24mm) similar in magnitude to the sum of the decrease in anterior chamber depth (0.450.21mm) and increase in anterior segment depth (0.520.23mm). Equatorial lens diameter increased (0.280.23mm) with no change in the posterior lens surface radius of curvature. Ciliary ring diameter decreased (0.570.41mm) with reduced circumlental space (0.430.15mm) and no forward ciliary body movement. Accommodative changes support the Helmholtz theory of accommodation including an increase in posterior lens surface curvature. Certain aspects of aging changes mimic accommodation.
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Most of creativity in the digital world passes unnoticed by the industry practices and policies, and it isn't taken into account in the cultural and economic strategies of the creative industries. We should find ways to catalyze this creative production, showing how the user's contribution may contribute to social learning, cultural and economic advancement. To that effect, we must know what is an open creative system and how it works. Based on this diagnosis, the author that interdisciplinarity is urgent and there is also a need for a science of culture. What is at stake is a strategy of integrated development, as regards the upcoming innovation in its complex, productive and learning aspects.
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Purpose: Investigations of foveal aberrations assume circular pupils. However, the pupil becomes increasingly elliptical with increase in visual field eccentricity. We address this and other issues concerning peripheral aberration specification. Methods: One approach uses an elliptical pupil similar to the actual pupil shape, stretched along its minor axis to become a circle so that Zernike circular aberration polynomials may be used. Another approach uses a circular pupil whose diameter matches either the larger or smaller dimension of the elliptical pupil. Pictorial presentation of aberrations, influence of wavelength on aberrations, sign differences between aberrations for fellow eyes, and referencing position to either the visual field or the retina are considered. Results: Examples show differences between the two approaches. Each has its advantages and disadvantages, but there are ways to compensate for most disadvantages. Two representations of data are pupil aberration maps at each position in the visual field and maps showing the variation in individual aberration coefficients across the field. Conclusions: Based on simplicity of use, adequacy of approximation, possible departures of off-axis pupils from ellipticity, and ease of understanding by clinicians, the circular pupil approach is preferable to the stretched elliptical approach for studies involving field angles up to 30 deg.
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The quest for the achievement of informed nature of science (NOS) views for all learners continues to inspire science educators to seek out effective instructional interventions to aid in the development of learners NOS views. Despite the extensive amount of research conducted in the field, the development of informed NOS views has been difficult to achieve, with many studies reporting difficulties in changing learners NOS views. Can engaging learners in argumentation lead to improvements in their NOS views? This review answers this question by examining studies which have explored NOS and argumentation in science education. The review also outlines a rationale for incorporating argumentation in science education, together with a brief overview of important recent studies in the field. Implications drawn from this review suggest that the incorporation of explicit NOS and argumentation instruction, together with consideration of various contextual, task-specific and personal factors which could mediate learners NOS views and engagement in argumentation, could lead to improvements in learners views of NOS.
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Curriculum developers and researchers have promoted context based programmes to arrest waning student interest and participation in the enabling sciences at high school and university. Context-based programmes aim for connections between scientific discourse and real-world contexts to elevate curricular relevance without diminishing conceptual understanding. Literature relating to context-based approaches to learning will be reviewed in this chapter. In particular, international trends in curricular development and results from evaluations of major projects (e.g. PLON, Salters Advanced Chemistry, ChemCom) will be highlighted. Research projects that explore context-based interventions focusing on such outcomes as student interest, perceived relevance and conceptual understanding also will feature in the review. The chapter culminates with a discussion of current context-based research that interprets classroom actions from a dialectical socio-cultural framework, and identifies possible new directions for research.
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Individual science teachers who have inspired colleagues to transform their classroom praxis have been labelled transformational leaders. As the notion of distributed leadership became more accepted in the educational literature, the focus on the individual teacher-leader shifted to the study of leadership praxis both by individuals (whoever they might be) and by collectives within schools and science classrooms. This review traces the trajectory of leadership research, in the context of learning and teaching science, from an individual focus to a dialectical relationship between individual and collective praxis. The implications of applying an individual-collective perspective to praxis for teachers, students and their designated leaders are discussed.