1,047 research outputs found
e-Tourism and Culture through Virtual Art Galleries: A pilot study of the usability of an interface
Virtual tours of museums and galleries are
becoming an increasingly common aspect of e-Tourism
marketing. This paper reports on a usability pilot study that
analyses the design of icons in a German 3-D virtual art gallery
interface. It evaluates the extent to which a sample of typical
computer users can interpret the meaning of icons from the
interface taken âout of contextâ. This was done by assessing a
sample of twenty-one icons representing the âactionâ,
âinformationâ and ânavigationâ functions. An Icon Intuitiveness
Test (IIT) was used to measure their Icon Recognition Rate
(IRR) and to classify them as âidentifiableâ, âmediocreâ or
âvagueâ according to an adapted stereotypy. The IIT results
show that the meaning of almost 30% of the icons was
misinterpreted or confused, which can seriously compromise
the usability of an interface. Based on these findings,
recommendations are made for icon redesign and replacement
and it is concluded that further research is needed into the
âlearnabilityâ of icons and usersâ understanding of icons in
context. It is contended that increased usability leading to an
improved user experience can have an economic impact on e-Tourism
Cellular eIF2B subunit localisation: implications for the integrated stress response and its control by small molecule drugs
eIF2 is a G protein critical for translation. It is tightly regulated in the integrated stress response (ISR) via phosphorylation of eIF2α and the subsequent control of eIF2B, a multisubunit guanine nucleotide exchange factor (GEF). Through studying the localisation of eIF2B subunits we identified cytoplasmic eIF2B bodies in mammalian cells. We highlight a relationship between body size and the eIF2B subunits localising to them; larger bodies contain all subunits and smaller bodies contain predominantly catalytic subunits. eIF2 localises to eIF2B bodies and shuttles within these bodies in a manner which correlates with eIF2B activity. Upon stress eIF2α-P localises predominately to larger bodies and results in a decreased shuttling of eIF2. Interestingly drugs which inhibit the ISR can rescue eIF2 shuttling in a manner correlating to levels of eIF2α-P. In contrast, smaller bodies show increased eIF2 shuttling in response to stress, which is accompanied by the localisation of eIF2BΎ to these bodies, suggesting the formation of a novel trimeric complex of eIF2B. This response is mimicked by ISR inhibiting drugs, providing insight into their potential mechanism of action. This study provides evidence that the composition and function of mammalian eIF2B bodies is regulated by the ISR and drugs which control it
Systematic review of reviews of symptoms and signs of COVID-19 in children and adolescents
OBJECTIVE: To undertake a systematic review of reviews of the prevalence of symptoms and signs of COVID-19 in those aged under 20 years. DESIGN: Narrative systematic review of reviews. PubMed, medRxiv, Europe PMC and COVID-19 Living Evidence Database were searched on 9 October 2020. SETTING: All settings, including hospitalised and community settings. PATIENTS: Children and young people (CYP) under age 20 years with laboratory-proven COVID-19. STUDY REVIEW, DATA EXTRACTION AND QUALITY: Potentially eligible articles were reviewed on title and abstract by one reviewer. Quality was assessed using the modified AMSTARS criteria and data were extracted from included studies by two reviewers. MAIN OUTCOME MEASURES: Prevalence of symptoms and signs of COVID-19. RESULTS: 1325 studies were identified and 18 reviews were included. Eight were high quality, 7 medium and 3 low quality. All reviews were dominated by studies of hospitalised children. The proportion of asymptomatic CYP ranged from 14.6% to 42%. Fever and cough were the the most common symptoms; proportions with fever ranged from 46% to 64.2% and with cough from 32% to 55.9%. All other symptoms or signs including rhinorrhoea, sore throat, headache, fatigue/myalgia and gastrointestinal symptoms including diarrhoea and vomiting were infrequent, occurring in less than 10%-20%. CONCLUSIONS: Fever and cough are the most common symptoms in CYP with COVID-19, with other symptoms infrequent. Further research on symptoms in community samples are needed to inform pragmatic identification and testing programmes for CYP
Could the Last Interglacial Constrain Projections of Future Antarctic Ice Mass Loss and SeaâLevel Rise?
Previous studies have interpreted Last Interglacial (LIG; âŒ129â116âka) sea-level estimates in multiple different ways to calibrate projections of future Antarctic ice-sheet (AIS) mass loss and associated sea-level rise. This study systematically explores the extent to which LIG constraints could inform future Antarctic contributions to sea-level rise. We develop a Gaussian process emulator of an ice-sheet model to produce continuous probabilistic projections of Antarctic sea-level contributions over the LIG and a future high-emissions scenario. We use a Bayesian approach conditioning emulator projections on a set of LIG constraints to find associated likelihoods of model parameterizations. LIG estimates inform both the probability of past and future ice-sheet instabilities and projections of future sea-level rise through 2150. Although best-available LIG estimates do not meaningfully constrain Antarctic mass loss projections or physical processes until 2060, they become increasingly informative over the next 130âyears. Uncertainties of up to 50âcm remain in future projections even if LIG Antarctic mass loss is precisely known (±5âcm), indicating that there is a limit to how informative the LIG could be for ice-sheet model future projections. The efficacy of LIG constraints on Antarctic mass loss also depends on assumptions about the Greenland ice sheet and LIG sea-level chronology. However, improved field measurements and understanding of LIG sea levels still have potential to improve future sea-level projections, highlighting the importance of continued observational efforts
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Could the Last Interglacial Constrain Projections of Future Antartic Ice Mass Loss and Sea-Level Rise?
Previous studies have interpreted Last Interglacial (LIG; âŒ129â116âka) seaâlevel estimates in multiple different ways to calibrate projections of future Antarctic iceâsheet (AIS) mass loss and associated seaâlevel rise. This study systematically explores the extent to which LIG constraints could inform future Antarctic contributions to seaâlevel rise. We develop a Gaussian process emulator of an iceâsheet model to produce continuous probabilistic projections of Antarctic seaâlevel contributions over the LIG and a future highâemissions scenario. We use a Bayesian approach conditioning emulator projections on a set of LIG constraints to find associated likelihoods of model parameterizations. LIG estimates inform both the probability of past and future iceâsheet instabilities and projections of future seaâlevel rise through 2150. Although bestâavailable LIG estimates do not meaningfully constrain Antarctic mass loss projections or physical processes until 2060, they become increasingly informative over the next 130âyears. Uncertainties of up to 50âcm remain in future projections even if LIG Antarctic mass loss is precisely known (±5âcm), indicating that there is a limit to how informative the LIG could be for iceâsheet model future projections. The efficacy of LIG constraints on Antarctic mass loss also depends on assumptions about the Greenland ice sheet and LIG seaâlevel chronology. However, improved field measurements and understanding of LIG sea levels still have potential to improve future seaâlevel projections, highlighting the importance of continued observational efforts
Assessing the impact of peat erosion on growing season CO2 fluxes by comparing erosional peat pans and surrounding vegetated haggs (article)
This is the author accepted manuscript. The final version is available from International Mire Conservation Group and International Peat Society via the DOI in this record.The research data supporting this publication are openly available from the University of Exeter's institutional repository at: https://doi.org/10.24378/exe.1143.Peatlands are recognised as an important but vulnerable ecological resource. Understanding the effects of existing damage, in this case erosion, enables more informed land management decisions to be made. Over the growing seasons of 2013 and 2014 photosynthesis and ecosystem respiration were measured using closed chamber techniques within vegetated haggs and erosional peat pans in Dartmoor National Park, southwest England. Below-ground total and heterotrophic respiration were measured and autotrophic respiration estimated from the vegetated haggs. The mean water table was significantly higher in the peat pans than in the vegetated haggs; because of this, and the switching from submerged to dry peat, there were differences in vegetation composition, photosynthesis and ecosystem respiration. In the peat pans photosynthetic CO2 uptake and ecosystem respiration were greater than in the vegetated haggs and strongly dependent on the depth to water table (r2>0.78, p<0.001). Whilst in the vegetated haggs, photosynthesis and ecosystem respiration had the strongest relationships with normalised difference vegetation index (NDVI) (r2=0.82, p<0.001) and soil temperature at 15 cm depth (r2=0.77, p=0.001). Autotrophic and total below-ground respiration in the vegetated haggs varied with soil temperature; heterotrophic respiration increased as water tables fell. An empirically derived net ecosystem model estimated that over the two growing seasons both the vegetated haggs (29 and 20 gC m 2; 95 % confidence intervals of -570 to 762 and -873 to 1105 gC m-2) and the peat pans (7 and 8 gC m 2; 95 % confidence intervals of -147 to 465 and -136 to 436 gC m 2) were most likely net CO2 sources. This study suggests that not only the visibly degraded bare peat pans but also the surrounding vegetated haggs are losing carbon to the atmosphere, particularly during warmer and drier conditions, highlighting a need for ecohydrological restoration.MomentaSouth West Water (SWW)Dartmoor National Park Authorit
Drain blocking has limited short-term effects on greenhouse gas fluxes in a Molinia caerulea dominated shallow peatland (article)
This is the final version. Available on open access from Elsevier via the DOI in this recordThe dataset associated with this article is available in ORE at https://doi.org/10.24378/exe.2723Drained peatlands dominated by purple moor grass (Molinia caerulea) are widespread in the UK and Western Europe. Although substantial carbon stores may be present in these peatlands, in this degraded state they are not currently acting as carbon sinks. Therefore, M.caerulea dominated peatlands have been identified as potential sites for ecohydrological restoration to tackle the current climate emergency. However, at present little is known about whether ditch blocking can raise water tables and promote the recovery of bog plant species, and the subsequent effects on carbon sequestration in these peatlands.
To investigate the potential for restoration, we measured changes in water table depth, vegetation composition, photosynthesis at 1000 ÎŒmol Photons mâ2 sâ1 (PG1000), ecosystem respiration (REco) and partitioned below-ground respiration in two M.caerulea dominated peatlands in which drainage ditches had been blocked located in Exmoor National Park, southwest England. Measurements were made in two headwater catchments at â
, Œ and œ of the distance between adjacent drainage ditches at four control-restored paired sites, during the growing seasons pre- (2012) and post- (2014, 2016 & 2018) restoration.
Restoration had a small but significant (p = 0.009) effect on water table depths however, this did not result in a significant change in vegetation composition (p > 0.350). Ecosystem respiration increased in both the control and restored locations following restoration however, this increase was significantly smaller (p = 0.010) at the restored locations, possibly due to a similarly reduced increase in photosynthesis, although this change was not significant (p = 0.116). Below-ground respiration showed no significant changes following restoration.
This research illustrates how degraded these shallow peatlands are, and raises concerns that ditch blocking alone may not bring about the high and stable water tables required to perturb the existing Molinia caerulea-dominated ecosystem and substantially alter the carbon balance. Additional restoration measures may be required.South West Water (SWW)University of ExeterTechnology Strategy Board CouncilNatural Environment Research Council (NERC
An Empirical Study of Icon Recognition in a Virtual Gallery Interface
This paper reports on an empirical study (an extension of a pilot study) that analyses the design of icons in a German 3-D virtual art gallery interface. It evaluates the extent to which a sample of typical computer users from a range of ages, educational attainments and employments can interpret the meaning of icons from the virtual interface taken âout of contextâ and âin contextâ. The study assessed a sample of 21 icons representing the âactionâ, âinformationâ and ânavigationâ functions of the virtual interface using a new Icon Recognition Testing method (IRT) developed by the researchers from existing usability test methods. The Icon Recognition Rate (IRR) of the icons was calculated and they were classified as âidentifiableâ, âmediocreâ or âvagueâ in a novel and useful classification system. The IRT results show that the IRR of almost a quarter of the icons was below the âidentifiableâ standard, which could seriously compromise the usability of a virtual interface. A comparison is made, using textual and thematic analysis, between the participantsâ understanding of the iconsâ meaning in and out of context and of the effect of positioning icons in relation to their virtual surroundings and of grouping them in tool bars. From the findings of the study, conclusions are drawn, and recommendations are made for economical icon redesign and replacement. It is suggested in the conclusions that further research is needed into how designersâ conceptual models can be better matched to usersâ mental models in the design of virtual interfaces by bringing user profiles into the study
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