20 research outputs found

    An investigation into the perspectives of providers and learners on MOOC accessibility

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    An effective open eLearning environment should consider the target learner’s abilities, learning goals, where learning takes place, and which specific device(s) the learner uses. MOOC platforms struggle to take these factors into account and typically are not accessible, inhibiting access to environments that are intended to be open to all. A series of research initiatives are described that are intended to benefit MOOC providers in achieving greater accessibility and disabled learners to improve their lifelong learning and re-skilling. In this paper, we first outline the rationale, the research questions, and the methodology. The research approach includes interviews, online surveys and a MOOC accessibility audit; we also include factors such the risk management of the research programme and ethical considerations when conducting research with vulnerable learners. Preliminary results are presented from interviews with providers and experts and from analysis of surveys of learners. Finally, we outline the future research opportunities. This paper is framed within the context of the Doctoral Consortium organised at the TEEM'17 conference

    GO-GN conceptual frameworks guide

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    This collaboratively written book brings together insights from a range of researchers into their use of conceptual frameworks in studying open education. Also included is an overview of different approaches to understanding the role(s) of theories and conceptual frameworks in doctoral research. In addition to discussing the different ways that conceptual frameworks are used we provide a (selective) overview of a range of conceptual frameworks and examples of their use. The GO-GN Conceptual Frameworks Guide is intended for those working in doctoral research but accessible enough to be used by anyone interested in carrying out a research project.Librar

    Biomineralization of amorphous Fe-, Mn- and Si-rich mineral phases by cyanobacteria under oxic and alkaline conditions

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    Iron and manganese are poorly soluble elements in oxic and alkaline solutions, whereas they are much more soluble under anoxic conditions. As a result, the formation of authigenic mineral phases rich in Fe and/or Mn has traditionally been viewed as diagnostic of global or local anoxic conditions. Here we reveal that some specific cyanobacteria of very small size (&lt; 2 µm, i.e., picocyanobacteria) can biomineralize abundant, authigenic Fe(III)-, Mn(IV)- and Si-rich amorphous phases under oxic conditions in an alkaline lake in Mexico. The resulting biominerals cluster as small globules arranged as rings around the division septum of cyanobacterial cells. These rings are enveloped within an organic, likely polysaccharidic envelope and are partially preserved, at least morphologically, upon sedimentation. Based on their 16S rDNA sequence, these cyanobacteria were affiliated with the Synechococcales order. The high Fe and Mn enrichment of the biominerals questions the systematic inference of anoxic conditions based on their detection. Moreover, this process scavenges iron from the water column, an overlooked biological contribution to the Fe cycle. Finally, it reveals a new case of controlled biomineralization of Si-rich phases by bacteria.</p

    Involvement of microbial mats in early fossilization by decay delay and formation of impressions and replicas of vertebrates and invertebrates

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    Microbial mats have been hypothesized to improve the persistence and the preservation of organic remains during fossilization processes. We test this hypothesis with long-term experiments (up to 5.5 years) using invertebrate and vertebrate corpses.Once placed on mats,the microbial community coats the corpses and forms a three-dimensional sarcophagus composed of microbial cells and exopolymeric substances (EPS). This coverage provides a template for i) moulding superficial features, resulting in negative impressions, and ii) generating replicas.The impressions of fly setulae, fish scales and frog skin verrucae are shaped mainly by small cells in an EPS matrix. Microbes also replicate delicate structures such as the three successive layers that compose a fish eye.The sarcophagus protects the body integrity, allowing the persistence of inner organs such as the ovaries and digestive apparatus in flies,the swim bladder and muscles in fish, and the bone marrow in frog legs.This study brings strong experimental evidence to the idea that mats favour metazoan fossilization by moulding, replicating and delaying decay. Rapid burial has classically been invoked as a mechanism to explain exceptional preservation. However, mats may play a similar role during early fossilization as they can preserve complex features for a long timeThis work, which is part of the research projects CGL2013-42643P and the research grant supporting M. Iniesto were funded by the Spanish Ministry of Economy and Competitiveness. The SEM facility at IMPMC was supported by Region Ile de France grant SESAME 2006 I-07-593/R, INSU-CNRS, INP-CNRS, and University Pierre et Marie Curie, Paris. SEM analyses performed for this study were supported by a grant from the Foundation Simone et Cino Del Duca (PI: K. Benzerara). Some SEM observations were also conducted at SIdI UAM (Madrid). Environmental SEM observations were performed at the MNCN (Madrid

    Analysing Disability Descriptions and Student Suggestions as a Foundation to Overcome Barriers to Learning

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    Artificial intelligence can support increasingly complex conversational interactions and also has the potential to interpret meanings from free text input and make recommendations based on patterns in data. There are important opportunities to apply this to real-world problems faced in access to education. In this paper, we summarise existing research and trends linking disability support and technology, then report on a survey conducted with students with disclosed disabilities (n = 138) to explore what systems might need to do to effectively understand disabled students in their own words, and provide suggestions of technologies, strategies and resources that could be relevant to overcoming barriers to learning. Through thematic analysis, five approaches that students used to talk about their disabilities are identified (medical, functional, support, experiential and administrative), and three major types of suggestions they make around what supported them and may be useful to others are also identified (external tools, university support and practices, concerns and solutions). The survey approach and the findings of the analysis provide a potential foundation for the effective design of systems that could crowdsource a knowledge base around disabilities, hold conversations to understand disabilities and barriers and make relevant recommendations to individuals as to how they could overcome these barriers

    Detection of almond allergen coding sequences in processed foods by real time PCR

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    The aim of this work was to develop and analytically validate a quantitative RT-PCR method, using novel primer sets designed on Pru du 1, Pru du 3, Pru du 4, and Pru du 6 allergen-coding sequences, and contrast the sensitivity and specificity of these probes. The temperature and/or pressure processing influence on the ability to detect these almond allergen targets was also analyzed. All primers allowed a specific and accurate amplification of these sequences. The specificity was assessed by amplifying DNA from almond, different Prunus species and other common plant food ingredients. The detection limit was 1 ppm in unprocessed almond kernels. The method's robustness and sensitivity were confirmed using spiked samples. Thermal treatment under pressure (autoclave) reduced yield and amplificability of almond DNA; however, high-hydrostatic pressure treatments did not produced such effects. Compared with ELISA assay outcomes, this RT-PCR showed higher sensitivity to detect almond traces in commercial foodstuffs

    Real Time PCR to detect hazelnut allergen coding sequences in processed foods

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    A quantitative RT-PCR method, employing novel primer sets designed on Cor a 9, Cor a 11 and Cor a 13 allergen-coding sequences has been setup and validated. Its specificity, sensitivity and applicability have been compared. The effect of processing on detectability of these hazelnut targets in complex food matrices was also studied. The DNA extraction method based on CTAB-phenol-chloroform was the best for hazelnut. RT-PCR using primers for Cor a 9, 11 and 13 allowed a specific and accurate amplification of these sequences. The limit of detection was 1 ppm of raw hazelnut. The method sensitivity and robustness were confirmed with spiked samples. Thermal treatments (roasting and autoclaving) reduced yield and amplificability of hazelnut DNA, however, high-hydrostatic pressure did not affect. Compared with an ELISA assay, this RT-PCR showed higher sensitivity to detected hazelnut traces in commercial foodstuffs. The RT-PCR method described is the most sensitive of those reported for the detection of hazelnut traces in processed foods. © 2012 Elsevier Ltd. All rights reserved

    The hidden role of dissolved organic carbon in the biogeochemical cycle of carbon in modern redox-stratified lakes

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    The dissolved organic carbon (DOC) reservoir holds a critical role in the C cycle of marine and fresh water environments because of its large size and involvement in many biogeochemical reactions. Despite poor constraints, its importance in ancient Earth’s C cycles is also commonly invoked. However, DOC remains rarely quantified and characterized in modern stratified analogs. Here, we investigated the DOC reservoirs of four redox-stratified alkaline crater lakes from Mexico. To achieve this, we analyzed the concentrations and isotopic compositions of DOC throughout the four water columns and compared them with existing data on dissolved inorganic and particulate organic C reservoirs (DIC and POC). The four lakes have high DOC concentrations with important variability between and within the lakes (averaging 2 ± 4 mM; 1SD, n=28; representing from ~ 15 to 160 times the amount of POC). δ13CDOC signatures also span a broad range of values from -29.3 to -8.7 ‰ (with as much as 12.5 ‰ variation within a single lake). The prominent DOC peaks (up to 21 mM), together with their associated isotopic variability, are interpreted to reflect oxygenic and/or anoxygenic primary productivity through the release of excess fixed-carbon in three of the lakes (Atexcac, La Preciosa and La Alberca de los Espinos). By contrast, the variability of [DOC] and δ13CDOC in Lake Alchichica was mainly explained by partial degradation of organic matter and accumulation of DOC in anoxic waters. Overall, DOC records detailed metabolic functioning such as active DIC-uptake and DIC-concentrating mechanism that cannot be inferred from DIC and POC analyses alone but that are critical to understand carbon fluxes from the environment to the biomass. Extrapolating our results to the geological record, we suggest that anaerobic oxidation of DOC may have caused the very negative C isotope excursions in the Neoproterozoic, but it is unlikely that a large oceanic DOC reservoir overweight the associated DIC reservoir. Overall, this study shows how the analysis of DOC in modern lakes deepens our understanding of the C cycle in stratified environments and how it can help to size boundary conditions to the Earth’s past oceans

    Detection by real time PCR of walnut allergen coding sequences in processed foods

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    A quantitative real-time PCR (RT-PCR) method, employing novel primer sets designed on Jug r 1, Jug r 3, and Jug r 4 allergen-coding sequences, was set up and validated. Its specificity, sensitivity, and applicability were evaluated. The DNA extraction method based on CTAB-phenol-chloroform was best for walnut. RT-PCR allowed a specific and accurate amplification of allergen sequence, and the limit of detection was 2.5 pg of walnut DNA. The method sensitivity and robustness were confirmed with spiked samples, and Jug r 3 primers detected up to 100 mg/kg of raw walnut (LOD 0.01%, LOQ 0.05%). Thermal treatment combined with pressure (autoclaving) reduced yield and amplification (integrity and quality) of walnut DNA. High hydrostatic pressure (HHP) did not produce any effect on the walnut DNA amplification. This RT-PCR method showed greater sensitivity and reliability in the detection of walnut traces in commercial foodstuffs compared with ELISA assays. © 2016 Elsevier Ltd. All rights reserved
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