Scientific representational fluency: Defining, diagnosing and developing

Scientific Representational Fluency: Defining, Diagnosing and Developing Matthew Hilla, Manjula Sharmaa, Helen Johnstona Presenting Author: Matthew Hill ([email protected]) aSchool of Physics, The University of Sydney, Sydney NSW 2006, Australia KEYWORDS: Multiple Representations, Physics, Representational Fluency Survey, Graphs, Words, Equations, Diagrams BACKGROUND Research into the multiple representations (e.g. graphs, words, equations and diagrams) used by scientists for reasoning and communication has progressed from focussing one individual representations, to an integrated skill set we refer to as representational fluency. Representational fluency incorporates making meaning from representations (metavisualization, Gilbert, 2008)), metacognitive awareness of the purposes and affordances of different representations (metarepresentational competence (diSessa, 2004)) with a recognition of the domain specific constellation of representational use with particular characteristics (representational competence (Kohl & Finkelstein, 2006). METHODS In 2012, we developed the Representational Fluency Survey (RFS) (Hill et al., In Press). To date this has been used with over 2000 physics students at The University of Sydney to diagnose representational fluency. Initially, the results have been used to further define characteristics of representational fluency and diagnose variation of representational fluency across a cross-section of physics students at the university. More recently, the RFS has diagnosed representational fluency development of first year students across the first semester of study at the university and informed the design of a sequence of 11 weekly online learning modules encouraging more varied representational use. RESULTS Two years of cross-sectional research revealed that there was a threshold of representational fluency distinguishable at The University of Sydney, specifically amongst the first year students. First year advanced students (those who scored well in high school physics) scored significantly better than those in the first year regular cohort (those who also did physics at high school with lower final marks). Notably, the regular students did not perform significantly better than those in the first year fundamental cohort even though fundamental students did not study physics in their final two years of high school. Individual student responses were coded and analysed for the representations used and the results indicate that students with a higher representational fluency use more representations and use representational modes that are typically more symbolic and visual than students with a lower representational fluency. 2014 data will be added to 2013 data regarding the development of representational fluency across students’ first semester of university and will be presented at the conference. CONCLUSIONS The RFS is a helpful tool that allows for the defining, diagnosing and development of representational fluency to take place. This has been demonstrated over multiple years of research in novel ways, helpful to the science education community. REFERENCES diSessa, A., (2004). Metarepresentation: Native competence and targets for instruction. Cognition and Instruction, 22(3). 293-331. doi: 10.1207/s1532690xci2203_2 Gilbert, J. K. (2008). Visualization: An Emergent Field of Practice and Enquiry in Science Education. In J. K. Gilbert, R. Miriam & M. Nakhleh (Eds.), Visualization: Theory and Practice in Science Education (pp. 3-24): Springer. Hill, M Reference TBC with the imminent publication of the paper. Kohl, P., & Finkelstein, N. (2006). Student representational competence and the role of instructional environment in introductory physics. In P. Heron, L. McCullough & J. Marx (Eds.), 2005 Physics Education Research Conference (Vol. 818, pp. 93-96). doi. 10.1063/1.217703

Developing representational skills through weekly online learning modules for first-year undergraduate physics students

Investigations at The University of Sydney over the last two years have revealed a potential gap between the representational ability (the ability to use graphs, words and equations to communicate and solve problems) of some of the first year physics students (a poster detailing this was presented at ACSME 2011). For semester 1 2013, 11 sets of research-based, online modules were created to specifically target the use of multiple representations when considering questions in physics. These pre-instruction modules, completed by half of the students randomly assigned, were designed to be relevant to the upcoming material to be covered in that week’s lectures which has been shown to be an effective way of introducing material to students (Seery & Donnelly, 2012). Parallel to the online modules were another set of modules targeting the conceptual knowledge required in first-year university physics. The large-scale study (n>500) involved the measurement of learning gains for conceptual and representational diagnostic tests over the semester including a longitudinal comparison with the representational ability of first-year students in previous years

Effect of vaccine dose on the safety and immunogenicity of a candidate TB vaccine, MVA85A, in BCG vaccinated UK adults.

PURPOSE: A non-randomised, open-label, Phase I safety and immunogenicity dose-finding study to assess the safety and immunogenicity of the candidate TB vaccine Modified Vaccinia virus Ankara expressing Antigen 85A (MVA85A) from Mycobacterium tuberculosis (MTB) in healthy adult volunteers previously vaccinated with BCG. METHODS: Healthy BCG-vaccinated volunteers were vaccinated with either 1×10(7) or 1×10(8)PFU of MVA85A. All adverse events were documented and antigen specific T cell responses were measured using an ex vivo IFN-γ ELISPOT assay. Safety and immunogenicity were compared between the 2 dose groups and with a previous trial in which a dose of 5×10(7)PFU MVA85A had been administered. RESULTS: There were no serious adverse events recorded following administration of either 1×10(7) or 1×10(8)PFU of MVA85A. Systemic adverse events were more frequently reported following administration of 1×10(8)PFU of MVA85A when compared to either 5×10(7) or 1×10(7)PFU of MVA85A but were mild or moderate in severity and resolved completely within 7 days of immunisation. Antigen specific T cell responses as measured by the IFN-γ ELISPOT were significantly higher following immunisation in adults receiving 1×10(8)PFU compared to the 5×10(7) and 1×10(7) doses. Additionally, a broader range of Ag85A epitopes are detected following 1×10(8)PFU of MVA85A. CONCLUSION: A higher dose of 1×10(8)PFU of MVA85A is well-tolerated, increases the frequency of IFN-γ secreting T cells detected following immunisation and broadens the range of Ag85A epitopes detected

Graduate attributes: implications for higher education practice and policy: Introduction

The higher education landscape is shifting under neo-liberal forces that are increasingly aligning the goals of business, government and education. This shift is engendering debate around the world about the role of higher education institutions in producing employable graduates to feed national prosperity in the emerging knowledge economy. As this evolution continues, we need to consider how we enhance generic graduate capabilities as well as the disciplinary expertise of our undergraduate students. Our graduates should possess the knowledge, skills and values to enable them to cope with dynamic employment opportunities, but they must also understand, through the benefits and constraints of their disciplinary perspectives, who they are and how they might contribute positively to the heterogeneity they will encounter in their local, regional and global communities

Downstream effects on human low density lipoprotein of homocysteine exported from endothelial cells in an in vitro system

A model system is presented using human umbilical vein endothelial cells (HUVECs) to investigate the role of homocysteine (Hcy) in atherosclerosis. HUVECs are shown to export Hcy at a rate determined by the flux through the methionine/Hcy pathway. Additional methionine increases intracellular methionine, decreases intracellular folate, and increases Hcy export, whereas additional folate inhibits export. An inverse relationship exists between intracellular folate and Hcy export. Hcy export may be regulated by intracellular S-adenosyl methionine rather than by Hcy. Human LDLs exposed to HUVECs exporting Hcy undergo time-related lipid oxidation, a process inhibited by the thiol trap dithionitrobenzoate. This is likely to be related to the generation of hydroxyl radicals, which we show are associated with Hcy export. Although Hcy is the major oxidant, cysteine also contributes, as shown by the effect of glutamate. Finally, the LDL oxidized in this system showed a time-dependent increase in uptake by human macrophages, implying an upregulation of the scavenger receptor. These results suggest that continuous export of Hcy from endothelial cells contributes to the generation of extracellular hydroxyl radicals, with associated oxidative modification of LDL and incorporation into macrophages, a key step in atherosclerosis. Factors that regulate intracellular Hcy metabolism modulate these effects. Copyright © 2005 by the American Society for Biochemistry and Molecular Biology, Inc

Developing graduate attributes through participation in undergraduate research conferences

© 2016 Taylor & Francis. Abstract: Graduate attributes are a framework of skills, attitudes, values and knowledge that graduates should develop by the end of their degree programmes. Adopting a largely qualitative approach and using semi-structured interviews, this paper outlines students’ experiences at a national undergraduate research conference over three years and evidences the graduate attributes developed. The students demonstrated intellectual autonomy, repurposing their work for presentation to a multidisciplinary audience through conversation with and benchmarking against peers. They gained confidence in expressing their identity as researchers and moved towards self-authorship, consciously balancing the contextual nature of their disciplinary knowledge with intra-personally grounded goals and values

Identification of antigens presented by MHC for vaccines against tuberculosis

Mycobacterium tuberculosis (M.tb) is responsible for more deaths globally than any other pathogen. The only available vaccine, bacillus Calmette-Guérin (BCG), has variable efficacy throughout the world. A more effective vaccine is urgently needed. The immune response against tuberculosis relies, at least in part, on CD4+ T cells. Protective vaccines require the induction of antigen-specific CD4+ T cells via mycobacterial peptides presented by MHC class-II in infected macrophages. In order to identify mycobacterial antigens bound to MHC, we have immunoprecipitated MHC class-I and class-II complexes from THP-1 macrophages infected with BCG, purified MHC class-I and MHC class-II peptides and analysed them by liquid chromatography tandem mass spectrometry. We have successfully identified 94 mycobacterial peptides presented by MHC-II and 43 presented by MHC-I, from 76 and 41 antigens, respectively. These antigens were found to be highly expressed in infected macrophages. Gene ontology analysis suggests most of these antigens are associated to membranes and involved in lipid biosynthesis and transport. The sequences of selected peptides were confirmed by spectral match validation and immunogenicity evaluated by IFN-gamma ELISpot against peripheral blood mononuclear cell from volunteers vaccinated with BCG, M.tb latently infected subjects or patients with tuberculosis disease. Three antigens were expressed in viral vectors, and evaluated as vaccine candidates alone or in combination in a murine aerosol M.tb challenge model. When delivered in combination, the three candidate vaccines conferred significant protection in the lungs and spleen compared with BCG alone, demonstrating proof-of-concept for this unbiased approach to identifying new candidate antigens

Sleeping trees and sleep-related behaviours of the siamang (Symphalangus syndactylus) in a tropical lowland rainforest, Sumatra, Indonesia

Sleeping tree selection and related behaviours of a family group and a solitary female siamang (Symphalangus syndactylus) were investigated over a 5-month period in northern Sumatra, Indonesia. We performed all day follows, sleeping tree surveys and forest plot enumerations in the field. We tested whether: (1) physical characteristics of sleeping trees and the surrounding trees, together with siamang behaviours, supported selection based on predation risk and access requirements; (2) the preferences of a solitary siamang were similar to those of a family group; and (3) sleeping site locations within home ranges were indicative of home range defence, scramble competition with other groups or other species, or food requirements. Our data showed that (1) sleeping trees were tall, emergent trees with some, albeit low, connectivity to the neighbouring canopy, and that they were surrounded by other tall trees. Siamangs showed early entry into and departure from sleeping trees, and slept at the ends of branches. These results indicate that the siamangs’ choice of sleeping trees and related behaviours were strongly driven by predator avoidance. The observed regular reuse of sleeping sites, however, did not support anti-predation theory. (2) The solitary female displayed selection criteria for sleeping trees that were similar to those of the family group, but she slept more frequently in smaller trees than the latter. (3) Siamangs selected sleeping trees to avoid neighbouring groups, monopolise resources (competition), and to be near their last feeding tree. Our findings indicate selectivity in the siamangs’ use of sleeping trees, with only a few trees in the study site being used for this purpose. Any reduction in the availability of such trees might make otherwise suitable habitat unsuitable for these highly arboreal small apes

Bench-to-bedside review : targeting antioxidants to mitochondria in sepsis

Peer reviewedPublisher PD

Angiosperm symbioses with non-mycorrhizal fungal partners enhance N acquisition from ancient organic matter in a warming maritime Antarctic

In contrast to the situation in plants inhabiting most of the world’s ecosystems, mycorrhizal fungi are usually absent from roots of the only two native vascular plant species of maritime Antarctica, Deschampsia antarctica and Colobanthus quitensis. Instead, a range of ascomycete fungi, termed dark septate endophytes (DSEs), frequently colonise the roots of these plant species. We demonstrate that colonisation of Antarctic vascular plants by DSEs facilitates not only the acquisition of organic nitrogen as early protein breakdown products, but also as non-proteinaceous D-amino acids and their short peptides, accumulated in slowly-decomposing organic matter, such as moss peat. Our findings suggest that, in a warming maritime Antarctic, this symbiosis has a key role in accelerating the replacement of formerly dominant moss communities by vascular plants, and in increasing the rate at which ancient carbon stores laid down as moss peat over centuries or millennia are returned to the atmosphere as CO2.Additional co-authors: Richard D Bardgett, David W Hopkins and Davey L Jone