952 research outputs found

    Everyday visual demands of people with low vision:A mixed methods real-life recording study

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    Research has demonstrated that low vison aids (LVAs) can have a positive impact on the functional sight of those living with sight loss. Step changes in technology are now enabling new wearable LVAs with greater potential than those available previously. For these novel devices to receive increased acceptance and therefore adoption by those with sight loss, visual task demands have to be understood more clearly in order to enable better alignment between device design and user requirements. The aim of this study was to quantify these requirements. Thirty-two participants aged 18 to 87 wore a spectacle-mounted video camera to capture and narrate all everyday situations in which they would use a "perfect" sight aid during 1 week. Captured scenes were analyzed through categorization and computational image analysis. Results showed large variation in activities and lifestyles. Participants reported no available sight aid or coping strategy for 57% of the recorded activities. Reading made up 49% of all recorded tasks, the other half comprising non-textual information. Overall, 75% of captured activities were performed ad hoc (duration of 0-5 minutes), 78% occurred indoors, 58% occurred at home, 48% were lit by natural light, 68% included the object of interest within reach, and 69% required a single focus plane only. Around half of captured objects of interest had a size of 2 degrees visual angle (2.08 logarithm of the minimum angle of resolution [logMAR]) or smaller. This study highlights the need for a sight aid that can make both textual and non-textual scenes accessible while offering flexibility to accommodate individual lifestyles

    Are wearable electronic vision enhancement systems (wEVES) beneficial for people with age-related macular degeneration? A scoping review

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    INTRODUCTION: Age-related macular degeneration (AMD) is the most common cause of irreversible visual impairment in the United Kingdom. It has a wide-ranging detrimental impact on daily living, including impairment of functional ability and quality of life. Assistive technology designed to overcome this impairment includes wearable electronic vision enhancement systems (wEVES). This scoping review assesses the usefulness of these systems for people with AMD. METHODS: Four databases (Cumulative Index to Nursing and Allied Health Literature, PubMed, Web of Science and Cochrane CENTRAL) were searched to identify papers that investigated image enhancement with a head-mounted electronic device on a sample population that included people with AMD. RESULTS: Thirty-two papers were included: 18 studied the clinical and functional benefits of wEVES, 11 investigated use and usability and 3 discussed sickness and adverse effects. CONCLUSIONS: Wearable electronic vision enhancement systems provide hands-free magnification and image enhancement producing significant improvements in acuity, contrast sensitivity and aspects of laboratory-simulated daily activity. Adverse effects were infrequent, minor and spontaneously resolved with the removal of the device. However, when symptoms arose, they sometimes persisted with continued device usage. There are multi-factorial influences and a diversity of user opinions on promotors to successful device use. These factors are not exclusively driven by visual improvement and incorporate other issues including device weight, ease of use and inconspicuous design. There is insufficient evidence of any cost-benefit analysis for wEVES. However, it has been shown that a user's decision to make a purchase evolves over time, with their estimates of cost falling below the retail price of the devices. Additional research is needed to understand the specific and distinct benefits of wEVES for people with AMD. Further patient-centred research should assess the benefits of wEVES in user-led activities when directly compared with alternative coping strategies, allowing professionals and users to make better prescribing and purchasing decisions

    The development of an automated sentence generator for the assessment of reading speed

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    Reading speed is an important outcome measure for many studies in neuroscience and psychology. Conventional reading speed tests have a limited corpus of sentences and usually require observers to read sentences aloud. Here we describe an automated sentence generator which can create over 100,000 unique sentences, scored using a true/false response. We propose that an estimate of the minimum exposure time required for observers to categorise the truth of such sentences is a good alternative to reading speed measures that guarantees comprehension of the printed material. Removing one word from the sentence reduces performance to chance, indicating minimal redundancy. Reading speed assessed using rapid serial visual presentation (RSVP) of these sentences is not statistically different from using MNREAD sentences. The automated sentence generator would be useful for measuring reading speed with button-press response (such as within MRI scanners) and for studies requiring many repeated measures of reading speed

    Predation on invasive cane toads (Rhinella marina) by native Australian rodents

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    © 2014, Springer-Verlag Berlin Heidelberg. The success of an invasive species can be reduced by biotic resistance from the native fauna. For example, an invader that is eaten by native predators is less likely to thrive than one that is invulnerable. The ability of invasive cane toads (Rhinella marina) to spread through Australia has been attributed to the toad’s potent defensive chemicals that can be fatal if ingested by native snakes, lizards, marsupials and crocodiles. However, several taxa of native insects and birds are resistant to cane toad toxins. If native rodents are also capable of eating toads (as suggested by anecdotal reports), these large, abundant and voracious predators might reduce toad numbers. Our field observations and laboratory trials confirm that native rodents (Melomys burtoni, Rattus colletti and Rattus tunneyi) readily kill and consume cane toads (especially small toads), and are not overtly affected by toad toxins. Captive rodents did not decrease their consumption of toads over successive trials, and ate toads even when alternative food types were available. In combination with anecdotal reports, our data suggest that rodents (both native and invasive) are predators of cane toads in Australia. Despite concerns about the decline of rodents following the invasion of toads, our data suggest that the species we studied are not threatened by toads as toxic prey, and no specific conservation actions are required to ensure their persistence

    Towards machine-assisted meta-studies: the Hubble constant

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    We present an approach for automatic extraction of measured values from the astrophysical literature, using the Hubble constant for our pilot study. Our rules-based model – a classical technique in natural language processing – has successfully extracted 298 measurements of the Hubble constant, with uncertainties, from the 208 541 available arXiv astrophysics papers. We have also created an artificial neural network classifier to identify papers in arXiv which report novel measurements. From the analysis of our results we find that reporting measurements with uncertainties and the correct units is critical information when distinguishing novel measurements in free text. Our results correctly highlight the current tension for measurements of the Hubble constant and recover the 3.5σ discrepancy – demonstrating that the tool presented in this paper is useful for meta-studies of astrophysical measurements from a large number of publications

    Can children measure their own vision? A comparison of three new contrast sensitivity tests

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    PURPOSE: To investigate the feasibility of children measuring their own contrast sensitivity using a range of tablet- and paper-based tests. METHODS: Forty children aged 5-15 years with amblyopia (N = 10), bilateral vision impairment (N = 10) or good vision (N = 20) measured their own vision on a screen-based optotype test (Manifold), a gamified vision test (PopCSF) and a paper-based test (Spotchecks) in a laboratory with minimal supervision. Completion rate, test-retest repeatability, test duration and participants' preferences were recorded for each test. RESULTS: Most participants (36/40) were able to perform all three tests. All tests were correlated with clinically measured visual acuity and contrast sensitivity (p < 0.001). The 95% coefficient of repeatability was 0.30 dB for Manifold, 0.29 dB for PopCSF and 0.13 dB for Spotchecks. All tests differentiated between children with reduced contrast sensitivity and control participants. PopCSF and Spotchecks were also able to differentiate between children with amblyopia and those with good vision. Median test time was 152, 130 and 202 s for Manifold, PopCSF and Spotchecks, respectively. Twenty-two participants preferred the PopCSF test, 10 preferred Spotchecks and 6 preferred Manifold. Thirty-nine out of the 40 children (98%) said they would measure their own vision at home using at least one of these tests every month. CONCLUSIONS: Children and young people can test their own contrast sensitivity with repeatable results. Of these three tests, the most repeatable was Spotchecks, the quickest was PopCSF and participants' favourite was PopCSF. Nearly all of the participants said they would be willing to use at least one of the three tests at home

    Projection of holograms from photorefractive OASLMs

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    Liquid crystals doped with fullerenes and carbon nanotubes (CNTs) act as good optical nonlinear materials. We have used these materials to build optically-addressed spatial light modulators (OASLMs). The devices comprise a single layer of doped liquid crystal acting as an active layer. Undoped LC devices with surfaces coated with fullerenes are also studied. Such OASLMs allow recording of phase holograms, and we record by imaging pre-calculated pre-recorded holograms. Writing is performed at normal incidence and reading at 45° oblique incidence. Both transmission and reflection modes of operation are used. Experimental results as well as comparison with commercially available OASLMs are presented

    A genome-wide association study on hematopoietic stem cell transplantation reveals novel genomic loci associated with transplant outcomes

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    Copyright \ua9 2024 Rosenberger, Crossland, Dressel, Kube, Wolff, Wulf, Bickeb\uf6ller, Dickinson and Holler.Introduction: Data on genomic susceptibility for adverse outcomes after hematopoietic stem cell transplantation (HSCT) for recipients are scarce. Methods: We performed a genome wide association study (GWAS) to identify genes associated with survival/mortality, relapse, and severe graft-versus-host disease (sGvHD), fitting proportional hazard and subdistributional models to data of n=1,392 recipients of European ancestry from three centres. Results: The single nucleotide polymorphism (SNP) rs17154454, intronic to the neuronal growth guidant semaphorin 3C gene (SEMA3C), was genome-wide significantly associated with event-free survival (p=7.0x10-8) and sGvHD (p=7.5x10-8). Further associations were detected for SNPs in the Paxillin gene (PXN) with death without prior relapse or sGvHD, as well as for SNPs of the Plasmacytoma Variant Translocation 1 gene (PVT1, a long non-coding RNA gene), the Melanocortin 5 Receptor (MC5R) gene and the WW Domain Containing Oxidoreductase gene (WWOX), all associated with the occurrence of sGvHD. Functional considerations support the observed associations. Discussion: Thus, new genes were identified, potentially influencing the outcome of HSCT

    Combined heart-liver transplantation for failing Fontan circulation in a late survivor with single-ventricle physiology

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    Management of adults with failing Fontan physiology poses many challenges, especially as transplantation offers the only realistic alternative to palliative care. We present the first combined heart and liver transplant performed in Europe, for a late survivor of single ventricle palliation with the Fontan circulation. In addition to the conventional medical and surgical challenges posed, we highlight the management of the associated multi-organ failure with focus on the liver and novel strategies for assessment and optimization
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