4,455 research outputs found

    Designing a programming-based approach for modelling scientific phenomena

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    We describe an iteratively designed sequence of activities involving the modelling of 1- dimensional collisions between moving objects based on programming in ToonTalk. Students aged 13-14 in two settings (London and Cyprus) investigated a number of collision situations, classified into six classes based on the relative velocities and masses of the colliding objects. We describe iterations of the system in which students engaged in a repeating cycle of activity for each collision class: prediction of object behaviour from given collision conditions, observation of a relevant video clip, building a model to represent the phenomena, testing, validating and refining their model, and publishing it – together with comments – on our web-based collaboration system, WebReports. Students were encouraged to consider the limitations of their current model, with the aim that they would eventually appreciate the benefit of constructing a general model that would work for all collision classes, rather than a different model for each class. We describe how our intention to engage students with the underlying concepts of conservation, closed systems and system states was instantiated in the activity design, and how the modelling activities afforded an alternative representational framework to traditional algebraic description

    Exploring the mathematics of motion through construction and collaboration

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    In this paper we give a detailed account of the design principles and construction of activities designed for learning about the relationships between position, velocity and acceleration, and corresponding kinematics graphs. Our approach is model-based, that is, it focuses attention on the idea that students constructed their own models – in the form of programs – to formalise and thus extend their existing knowledge. In these activities, students controlled the movement of objects in a programming environment, recording the motion data and plotting corresponding position-time and velocity-time graphs. They shared their findings on a specially-designed web-based collaboration system, and posted cross-site challenges to which others could react. We present learning episodes that provide evidence of students making discoveries about the relationships between different representations of motion. We conjecture that these discoveries arose from their activity in building models of motion and their participation in classroom and online communities

    CPD 1 - Embedding Epistemic Insight and Big Questions across a whole school curriculum

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    Professional development workshop. Explanation of Epistemic Insight pedagogical approach, tools and resources to help embed Big questions into a school-wide curriculum

    One Little Dream of Love : Song

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    https://digitalcommons.library.umaine.edu/mmb-vp/2332/thumbnail.jp

    Using Functional Near Infrared Spectroscopy (fNIRS) to study dynamic stereoscopic depth perception

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    The parietal cortex has been widely implicated in the processing of depth perception by many neuroimaging studies, yet functional near infrared spectroscopy (fNIRS) has been an under-utilised tool to examine the relationship of oxy- ([HbO]) and de-oxyhaemoglobin ([HbR]) in perception. Here we examine the haemodynamic response (HDR) to the processing of induced depth stimulation using dynamic random-dot-stereograms (RDS). We used fNIRS to measure the HDR associated with depth perception in healthy young adults (n = 13, mean age 24). Using a blocked design, absolute values of [HbO] and [HbR] were recorded across parieto-occipital and occipital cortices, in response to dynamic RDS. Control and test images were identical except for the horizontal shift in pixels in the RDS that resulted in binocular disparity and induced the percept of a 3D sine wave that 'popped out' of the test stimulus. The control stimulus had zero disparity and induced a 'flat' percept. All participants had stereoacuity within normal clinical limits and successfully perceived the depth in the dynamic RDS. Results showed a significant effect of this complex visual stimulation in the right parieto-occipital cortex (p < 0.01, η(2) = 0.54). The test stimulus elicited a significant increase in [HbO] during depth perception compared to the control image (p < 0.001, 99.99 % CI [0.008-0.294]). The similarity between the two stimuli may have resulted in the HDR of the occipital cortex showing no significant increase or decrease of cerebral oxygenation levels during depth stimulation. Cerebral oxygenation measures of [HbO] confirmed the strong association of the right parieto-occipital cortex with processing depth perception. Our study demonstrates the validity of fNIRS to investigate [HbO] and [HbR] during high-level visual processing of complex stimuli

    The Arabidopsis epitranscriptome

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    The most prevalent internal modification of plant messenger RNAs, N6-methyladenosine (m6A), was first discovered in the 1970s, then largely forgotten. However, the impact of modifications to eukaryote mRNA, collectively known as the epitranscriptome, has recently attracted renewed attention. mRNA methylation is required for normal Arabidopsis development and the first methylation maps reveal that thousands of Arabidopsis mRNAs are methylated. Arabidopsis is likely to be a model of wide utility in understanding the biological impacts of the epitranscriptome. We review recent progress and look ahead with questions awaiting answers to reveal an entire layer of gene regulation that has until recently been overlooked

    The Regulation of Surface Responsive Genes in Blumeria graminis f. sp. hordei

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    Powdery mildew of barley is caused by the ascomycete pathogen Blumeria graminis f. sp. hordei (Bgh). Bgh is economically important throughout the world, causing crop losses varying between 5 to 20 % and in extreme cases as much as 60 %. Bgh is an obligate biotroph, relying on its host for growth and reproduction. This characteristic has hindered attempts to carry out biochemical and molecular biological analysis. Previous work had highlighted differential gene expression during Bgh development on surfaces other than the host. Consequently, this thesis had three aims. The first attempted to elucidate the nature of this gene expression. Work listed within includes studies of Bgh morphological development on the host barley, wheat, cellulose membrane, and glass. Additional studies included the assessment of gene expression, via RT-qPCR, on glass surfaces enhanced with 1-hexacosonal (a synthetic C26 aldehyde known to spur Bgh development), 16-hydroxyhexadecanoic acid (a cutin monomer found within the barley leaf), as well as surfaces of differing hydrophobicity. Results collected reenforce the surface-dependent nature of gene regulation, and highlight how gene expression is determined by the integration of multiple signal inputs. The second aim of this thesis was the transformation of Bgh utilising Agrobacterium tumefaciens. Efforts are discussed as are approaches for future work aimed at transforming this fungus. The final aim of the thesis aimed to lay foundations for work involving the assessment of 5‟-regulatory regions of genes showing clustered, and differential, expression on alternate surfaces. Utilising the phytopathogenic model fungus Magnaporthe oryzae (the causal agent of rice blast disease), 22 promoter regions were tested for their ability to drive GFP in this pathogen. 2 regions (for genes encoding a H4 histone and an aconitase) along with promoter regions selected for their conservation, were able to do so

    Teaching sustainability and stewardship workshop 1: Collaborative approach to developing engagement with science and religion: Exploring sustainability in an international learning community

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    Workshop 1 introduces a collaborative approach to developing engagement with science and religion, by exploring sustainability in an international learning community of teachers based in Pakistan and England. The aim of the session was to begin to explore sustainability through science and religious worldviews. Participants were invited to: 1. Explore the meaning of the term ‘sustainability’ 2. Consider the relationship between science and religion 3. Reflect on the nature and communication of knowledge 4. Explore the Learning Community Blackboar

    Science, religion and sustainability in schools: outlining a teacher learning community approach.

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    Sustainability is a large and growing field in educational research. Existing research has explored conceptually how the science/religion dialogue might inform sustainability education. This has the potential to enrich sustainability education by acknowledging difference and better engaging students across different religions and worldviews. Fostering a multidisciplinary approach to sustainability education in schools can help create connections between science, RE, geography, economics, and history, as these all contribute to critical thinking and inform compassionate action that supports social justice. Epistemically insightful approaches to teaching and learning have the potential to support this vital dialogue and push back against compartmentalization. In this presentation, we will discuss preliminary work and findings for our pilot study with ECTs, funded by the International Network for Science and Belief in Society. Our project will assess the potential of a cross-national (England and Pakistan) teacher research community model for co-creating resources and approaches that address the above issues of the conflict model, compartmentalization and lack of understanding/confidence in the delivery of sustainability education across different curriculum subjects

    The effect of ambient temperature on cold start urban traffic emissions for a real world SI car

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    The influence of ambient temperature on exhaust emissions for an instrumented Euro 1 SI car was determined. A real world test cycle was used, based on an urban drive cycle that was similar to the ECE urban drive cycle. It was based on four laps of a street circuit and an emissions sample bag was taken for each lap. The bag for the first lap was for the cold start emissions. An in-vehicle direct exhaust dual bag sampling technique was used to simultaneously collect exhaust samples upstream and downstream of the three-way catalyst (TWC). The cold start tests were conducted over a year, with ambient temperatures ranging from – 2°C to 32°C. The exhaust system was instrumented with thermocouples so that the catalyst light off temperature could be determined. The results showed that CO emissions for the cold start were reduced by a factor of 8 downstream of catalyst when ambient temperature rose from -2°C to 32°C, the corresponding hydrocarbon emissions were reduced by a factor of 4. There was no clear relationship between NOx emissions and ambient temperature. For subsequent laps of the test circuit the reduction of CO and HC emissions as a function of ambient temperature was lower. The time for catalyst light off increased by 50% as the ambient temperature was reduced. The results show that the vehicle used is unlikely to meet the new – 7oC cold start CO emission regulations
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