3,477 research outputs found

    Transparent materials processing system

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    A zero gravity processing furnace system was designed that will allow acquisition of photographic or other visual information while the sample is being processed. A low temperature (30 to 400 C) test model with a flat specimen heated by quartz-halide lamps was constructed. A high temperature (400 to 1000 C) test model heated by resistance heaters, utilizing a cylindrical specimen and optics, was also built. Each of the test models is discussed in detail. Recommendations are given

    The effectiveness of a social media intervention for reducing portion sizes in young adults and adolescents

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    open access journalAbstract Objective: Adolescents and young adults select larger portions of energy-dense food than recommended. The majority of young people have a social media profile, and peer influence on social media may moderate the size of portions selected. Methods: Two pilot-interventions examined whether exposure to images of peers’ portions of high-energy-dense (HED) snacks and sugar-sweetened-beverages (SSBs) on social media (Instagram) would influence reported desired portions selected on a survey. Confederate peers posted ‘their’ portions of HED snacks and SSBs on Instagram. At baseline and intervention end participants completed surveys that assessed desired portion sizes. Results: In intervention 1, Undergraduate students (N=20, Mean age=19.0y, SD=0.65y) participated in a two-week intervention in a within-subjects design. Participants reported smaller desired portions of HED snacks and SSBs following the intervention, and smaller desired portions of HED snacks for their peers. In intervention 2, adolescents (N=44, Mean age=14.4y, SD=1.06y) participated in a four-week intervention (n=23) or control condition (n=21) in a between-subjects design. Intervention 2 did not influence adolescents to reduce their desired reported portion sizes of HED snacks or SSBs relative to control. Conclusions: These preliminary studies demonstrated that social media is a feasible way to communicate with young people. However, while the intervention influenced young adults’ reported desired portions and social norms regarding their peers’ portions, no significant impact on desired reported portion sizes was found for HED snacks and SSBs in adolescents. Desired portion sizes of some foods and beverages may be resistant to change via a social media intervention in this age group

    Computational challenges of systems biology

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    Progress in the study of biological systems such as the heart, brain, and liver will require computer scientists to work closely with life scientists and mathematicians. Computer science will play a key role in shaping the new discipline of systems biology and addressing the significant computational challenges it poses

    A material-dialogic perspective on powerful knowledge and matter within a science classroom

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    “Powerful” disciplinary knowledge has the potential to enrich students’ lives by providing access to understanding beyond everyday experience (Young 2011). Learning science or any other school subject requires understanding of the core body of content within an academic discipline. However, contemporary discussion of disciplinary knowledge remains at the sociological level, offering little clarity around how such knowledge manifests in the complex and unique contexts in which people learn. The framing of powerful knowledge inherits a dualist philosophical assumption that a curriculum concept is a universal phenomenon, acquired through a myriad of activities and applied in new situations, but nevertheless something which is acquired (or not) (Hardman, 2019). The question then becomes how these universal concepts are acquired through the unique context of a specific classroom. Gericke et al. (2018) begin to address this question by highlighting the transformations made as disciplinary knowledge is taught in schools. These transformations occur at the societal, institutional and classroom levels. The term ‘transformation’ is an umbrella term reflected in both the tradition of didactics, for example, ‘didactic transposition’ (Chevallard 2007), ‘omstilling’ (Ongstad 2006) and ‘reconstruction’ (Duit 2013), as well as within the curriculum tradition in Bernstein’s (1973) notion of ‘re-contextualization’. As well as considering transformations, the term epistemic quality moves us towards conceptualizing how classroom activities have differing qualities in conveying the epistemology of disciplines (Hudson, 2018). In this chapter, we focus on the classroom, and seek to address the overarching question of: How can the transformation processes related to powerful knowledge and epistemic quality be described? Our contention is that the notions of transformation and epistemic quality hold the potential to frame the ways in which disciplinary knowledge and epistemology manifest in the classroom. However, as these notions are being developed, in this book and elsewhere, we wish to guard against any simplistic framing whereby idealised disciplinary understandings are in some way represented in classrooms. In our view, a learner does not receive a reduced, simplified form of some universal understanding. Understanding of a subject discipline, in terms of both knowledge and the epistemology of the discipline, emerge from the dynamic, messy and material contexts of classrooms. In this chapter, we consider how a material-dialogic frame (Hetherington et al. 2018; Hetherington and Wegerif, 2018) might contribute to this discussion. We first briefly lay out the material-dialogic frame and our reasons for proposing it. After that, we use a case study of a science classroom to support the usefulness of the frame in considering transformations of disciplinary knowledge in classrooms
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