79 research outputs found

    Diagnosing student errors in e-Assessment questions

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    © The Author 2015. We demonstrate how the re-marker and reporter facility of the DEWIS e-Assessment system facilitates the capture, analysis and reporting of student errors using two case studies: logarithms and indices for first-year computing students at the University of the West of England, and Sturm-Liouville problems for second-year mathematics students at Leeds University. The differences in approach needed for error capture for commonly used numerical or algebraic answer inputs are discussed and shown to facilitate efficient capture and reporting of student errors. Not only does such information provide away to tailor question feedback to address these errors for use by future students, but can be made available to current students by re-marking their answers using the newly identified errors and hencemaking the improved feedback available to them too

    Vented Chill / No-Vent Fill of Cryogenic Propellant Tanks

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    Architectures for extended duration missions often include an on-orbit replenishment of the space vehicle's cryogenic liquid propellants. Such a replenishment could be accomplished via a tank-to-tank transfer from a dedicated tanker or a more permanent propellant depot storage tank. Minimizing the propellant loss associated with transfer line and receiver propellant tank thermal conditioning is essential for mass savings. A new methodology for conducting tank-to-tank transfer while minimizing such losses has been demonstrated. Charge-Hold-Vent is the traditional methodology for conducting a tank-to-tank propellant transfer. A small amount of cryogenic liquid is introduced to chill the transfer line and propellant tank. As the propellant absorbs heat and undergoes a phase change, the tank internal pressure increases. The tank is then vented to relieve pressure prior to another charge of cryogenic liquid being introduced. This cycle is repeated until the transfer lines and tank are sufficiently chilled and the replenishment of the propellant tank is complete. This method suffers inefficiencies due to multiple chill and vent cycles within the transfer lines and associated feed system components. Additionally, this system requires precise measuring of cryogenic fluid delivery for each transfer, multiple valve cycling events, and other complexities associated with cycled operations. To minimize propellant loss and greatly simplify on-orbit operations, an alternate methodology has been designed and demonstrated. The Vented Chill / No Vent Fill method is a simpler, constant flow approach in which the propellant tank and transfer lines are only chilled once. The receiver tank is continuously vented as cryogenic liquid chills the transfer lines, tank mass and ullage space. Once chilled sufficiently, the receiver tank valve is closed and the tank is completely filled. Interestingly, the vent valve can be closed prior to receiver tank components reaching liquid saturation temperature. An incomplete fill results if insufficient energy is removed from the tank's thermal mass and ullage space. The key to successfully conducting the no vent fill is to assure that sufficient energy is removed from the system prior to closing the receiver tank vent valve. This paper will provide a description of the transfer methodology and test article, and will provide a discussion of test results

    Comparing socio-economic measures as predictors of educational attainment.

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    Objectives and Approach Free School Meals (FSM) has commonly been used as a proxy for economic disadvantage or low socio-economic background within educational research in the UK, as eligibility is based upon receipt of government welfare benefits. It is also used by government in funding decisions for schools. However, in December 2021 the Welsh Government announced that the offer of FSM will be expanded to all pupils in primary schools, meaning that this measure will no longer be available as a proxy. Our objective is therefore to considers the potential of other administrative sources of socio-economic information to fill this gap. Linking administrative education data and Census 2011 data for Wales, we undertook descriptive and regression analyses to consider how Census measures of deprivation act compared to the FSM measure in predicting attainment. Results Our descriptive results show that not all pupils who are eligible for FSM are captured by the Census measures. However, our regression results indicate that socio-economic indicators from the Census – namely highest household qualification, approximated social grade and economic inactivity – all behave in a similar fashion to that of the proxy measure, FSM in association with pupil attainment. Conclusion We consider results in comparison to studies using survey data, and discuss implications for the future measurement of economic disadvantage in Wales among primary school pupils

    'Mindless markers of the nation': The routine flagging of nationhood across the visual environment

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    The visual environment has increasingly been used as a lens with which to understand wider processes of social and economic change with studies employing in-depth qualitative approaches to focus on, for example, gentrification or trans-national networks. This exploratory paper offers an alternative perspective by using a novel method, quantitative photo mapping, to examine the extent to which a particular socio-cultural marker, the nation, is ‘flagged’ across three contrasting sites in Britain. As a multi-national state with an increasingly diverse population, Britain offers a particularly fruitful case study, drawing in debates around devolution, European integration and Commonwealth migration. In contributing to wider debates around banal nationalism, the paper notes the extent to which nations are increasingly articulated through commerce, consumption and market exchange and the overall significance of everyday markers (signs, objects, infrastructure) in naturalising a national view of the world

    Targeting Extracellular Vesicles to the Arthritic Joint using a Damaged Cartilage Specific Antibody

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    The targeted delivery of therapies to diseased tissues offers a safe opportunity to achieve optimal efficacy whilst limiting systemic exposure. These considerations apply to many disease indications, but are especially relevant for rheumatoid arthritis (RA), as RA is a systemic autoimmune disease which affects multiple joints. We have identified an antibody that is specific to damaged arthritic cartilage (anti-ROS-CII) that can be used to deliver treatments specifically to arthritic joints, yielding augmented efficacy in experimental arthritis. In the current study, we demonstrate that scaffold enriched with bioactive payloads can be delivered precisely to an inflamed joint and achieve superior efficacy outcomes consistent with the pharmacological properties of these payloads. As a scaffold, we have used extracellular vesicles (EV) prepared from human neutrophils (PMN), which possess intrinsic anti-inflammatory properties and the ability to penetrate inflamed arthritic cartilage. EV fortified with anti-ROS-CII (EV/anti-ROS-CII) retained anti-ROS-CII specificity and bound exclusively to the damaged cartilage. Following systemic administration EV/anti-ROS-CII: a) exhibited the ability to localise specifically in the arthritic joint in vivo and b) was able to specifically target single (viral IL-10 or anti-TNF) or combined (viral IL-10 and anti-TNF) anti-inflammatory treatments to the arthritic joint, which accelerated attenuation of clinical and synovial inflammation. Overall, this study demonstrates the attainability of targeting a pro-resolving biological scaffold to the arthritic joint. The potential of targeting scaffolds such as EV, nanoparticles or combination thereof alongside combined therapeutics is paramount for designing systemically administered broad-spectrum of anti-inflammatory treatments

    A HIF-LIMD1 negative feedback mechanism mitigates the pro-tumorigenic effects of hypoxia

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    The adaptive cellular response to low oxygen tensions is mediated by the hypoxia inducible factors (HIFs), a family of heterodimeric transcription factors composed of HIF-α and β subunits. Prolonged HIF expression is a key contributor to cellular transformation, tumourigenesis and metastasis. As such, HIF degradation under hypoxic conditions is an essential homeostatic and tumour suppressive mechanism. LIMD1 complexes with PHD2 and VHL in physiological oxygen levels (normoxia) to facilitate proteasomal degradation of the HIF-α subunit. Here, we identify LIMD1 as a HIF-1 target gene, which mediates a previously uncharacterised, negative regulatory feedback mechanism for hypoxic HIF-α degradation by modulating PHD2-LIMD1- VHL complex formation. Hypoxic induction of LIMD1 expression results in increased HIF-α protein degradation, inhibiting HIF-1 target-gene expression, tumour growth and vascularisation. Furthermore, we report that copy number variation at the LIMD1 locus occurs in 47.1% of lung adenocarcinoma patients, correlates with enhanced expression of a HIF target gene signature and is a negative prognostic indicator. Taken together, our data open a new field of research into the aetiology, diagnosis and prognosis of LIMD1-negative lung cancers

    Cellular heterogeneity of pluripotent stem cell-derived cardiomyocyte grafts is mechanistically linked to treatable arrhythmias

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    Preclinical data have confirmed that human pluripotent stem cell-derived cardiomyocytes (PSC-CMs) can remuscularize the injured or diseased heart, with several clinical trials now in planning or recruitment stages. However, because ventricular arrhythmias represent a complication following engraftment of intramyocardially injected PSC-CMs, it is necessary to provide treatment strategies to control or prevent engraftment arrhythmias (EAs). Here, we show in a porcine model of myocardial infarction and PSC-CM transplantation that EAs are mechanistically linked to cellular heterogeneity in the input PSC-CM and resultant graft. Specifically, we identify atrial and pacemaker-like cardiomyocytes as culprit arrhythmogenic subpopulations. Two unique surface marker signatures, signal regulatory protein α (SIRPA)+CD90−CD200+ and SIRPA+CD90−CD200−, identify arrhythmogenic and non-arrhythmogenic cardiomyocytes, respectively. Our data suggest that modifications to current PSC-CM-production and/or PSC-CM-selection protocols could potentially prevent EAs. We further show that pharmacologic and interventional anti-arrhythmic strategies can control and potentially abolish these arrhythmias

    Higher Education Outreach : Examining Key Challenges for Academics

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    How should academic staff engage in outreach with communities outside of the university? The need of academics to answer this question has intensified in the UK given the changing priorities of academic job roles, shaped by increasing institutional concern for widening participation, graduate employability and research impact in an era of austerity and high tuition fees. While university outreach professionals, such as those in widening participation, have access to a range of networks, resources and support mechanisms for outreach activity, academics often face a series of profession-specific pressures that make engagement in outreach complex and contingent. This article draws upon the experience of 25 academics from 18 different subject areas and 18 institutions to examine and provide responses to key challenges faced by academics involved in outreach in the UK. We examine such issues as: the conceptualisation of outreach; funding; recognition and management of workload; nurturing relationships with internal and external partners; capacity-building; commercial interests, payment and responsibility; pedagogical style and content; integration of outreach into curricula, and evaluation of programmes. The examination offered is not all encompassing, but acts as a series of reference points to consider the challenges faced by UK academics in an evolving outreach sector
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