117 research outputs found

    Driving slow motorised vehicles with visual impairment:An exploration of driving safety

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    Independent mobility is important for social participation and many people with visual impairment are dependent on the use of slow motorised vehicles. These vehicles are defined as motor vehicles with a maximum speed of 45 km/h (e.g., microcars or mobility scooters). Legal visual standards for the use of these vehicles do not exist. Yet, it is unclear to what extent people with visual impairment can use slow motorised vehicles safely and responsively. In her PhD research, Christina Cordes investigated the visual and cognitive factors that influence safe traffic participation in microcars and mobility scooters. Driving performance was investigated using a real mobility scooter and a mobility scooter and microcar driving simulator in both normal sighted and visually impaired participants with (very) low visual acuity and/or visual field defects. In addition, a neuropsychological test battery was administered. Most participants were able to acquire the skills necessary to drive mobility scooters safely in only a short time. Although visually impaired people were evaluated worse on the mobility scooter on-road test compared to normal sighted participants, they performed well enough to be able to participate in traffic safely. Participants with visual field defects appeared to have more difficulties in traffic than people with low visual acuity. The driving simulator tasks further revealed that small obstacles with low contrast posed the greatest risk of collision for visually impaired drivers. It can be concluded that visual impairment alone cannot determine if someone can safely participate in traffic using slow motorised vehicles. Individual advice is needed, especially for people with visual field defects. People can be trained to compensate for their visual impairments in order to use slow motorised vehicles safely and responsibly, despite their limitations

    Driving slow motorised vehicles with visual impairment:An exploration of driving safety

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    The neuropsychological rehabilitation of visual agnosia and Balint’s syndrome

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    Visual agnosia and Balint’s syndrome are complex neurological disorders of the higher visual system that can have a remarkable impact on individuals’ lives. Rehabilitation of these individuals is important to enable participation in everyday activities despite the impairment. However, the literature about the rehabilitation of these disorders is virtually silent. Therefore, the aim of this systematic review is to give an overview of available literature describing treatment approaches and their effectiveness with regard to these disorders. The search engines Psychinfo, Amed, and Medline were used, resulting in 22 articles meeting the criteria for inclusion. Only articles describing acquired disorders were considered. These articles revealed that there is some information available on the major subtypes of visual agnosia as well as on Balint’s syndrome which practising clinicians can consult for guidance. With regard to the type of rehabilitation, compensatory strategies have proven to be beneficial in most of the cases. Restorative training on the other hand has produced mixed results. Concluding, although still scarce, a scientific foundation about the rehabilitation of visual agnosia and Balint’s syndrome is evolving. The available approaches give valuable information that can be built upon in the future

    The effect of target speed on perception of visual motion direction in a patient with akinetopsia

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    Although much research has been devoted to the neural correlates of motion perception, the processing of speed of motion is still a topic of discussion. Apart from patient LM, no in-depth clinical research has been done in the past 20 years on this topic. In the present study, we investigated patient TD, who suffered from the rare disorder akinetopsia due to bilateral lesions of V5 after stroke. By means of a Random-Dot-Kinematogram (RDK) in which speed was varied systematically, it was found that TD was impaired in perceiving the direction of movement at speeds exceeding 9 deg/s. Our study suggests that V5 plays an important role in processing high-speed visual motion and further implies that V5 does not play a crucial role in processing low-speed visual motion. A remarkable finding, which has not been shown before, was that TD always reported the opposite direction of the actual movement at a speed of 24 deg/s. This suggests a form of the continuous wagon wheel illusion, which might have been caused by intact brain areas operating at different sampling rates than area V5

    Vitamin D receptor regulates intestinal proteins involved in cell proliferation, migration and stress response

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    BACKGROUND: Genome-wide association studies found low plasma levels of 25-hydroxyvitamin D and vitamin D receptor (VDR) polymorphisms associated with a higher prevalence of pathological changes in the intestine such as chronic inflammatory bowel diseases. METHODS: In this study, a proteomic approach was applied to understand the overall physiological importance of vitamin D in the small intestine, beyond its function in calcium and phosphate absorption. RESULTS: In total, 569 protein spots could be detected by two-dimensional-difference in-gel electrophoresis (2D-DIGE), and 82 proteins were considered as differentially regulated in the intestinal mucosa of VDR-deficient mice compared to that of wildtype (WT) mice. Fourteen clearly detectable proteins were identified by MS/MS and further analyzed by western blot and/or real-time RT-PCR. The differentially expressed proteins are functionally involved in cell proliferation, cell adhesion and cell migration, stress response and lipid transport. Mice lacking VDR revealed higher levels of intestinal proteins associated with proliferation and migration such as the 37/67 kDa laminin receptor, collagen type VI (alpha 1 chain), keratin-19, tropomyosin-3, adseverin and higher levels of proteins involved in protein trafficking and stress response than WT mice. In contrast, proteins that are involved in transport of bile and fatty acids were down-regulated in small intestine of mice lacking VDR compared to WT mice. However, plasma and liver concentrations of cholesterol and triglycerides were not different between the two groups of mice. CONCLUSION: Collectively, these data imply VDR as an important factor for controlling cell proliferation, migration and stress response in the small intestine

    Arxula adeninivorans Recombinant Guanine Deaminase and Its Application in the Production of Food with Low Purine Content

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    Purines of exogenous and endogenous sources are degraded to uric acid in human beings. Concentrations >6.8 mg uric acid/dl serum cause hyperuricemia and its symptoms. Pharmaceuticals and the reduction of the intake of purine-rich food are used to control uric acid levels. A novel approach to the latter proposition is the enzymatic reduction of the purine content of food by purine-degrading enzymes. Here we describe the production of recombinant guanine deaminase by the yeast Arxula adeninivorans LS3 and its application in food. In media supplemented with nitrogen sources hypoxanthine or adenine, guanine deaminase (AGDA) gene expression is induced and intracellular accumulation of guanine deaminase (Agdap) protein occurs. The characteristics of the guanine deaminase isolated from wild-type strain LS3 and a transgenic strain expressing the AGDA gene under control of the strong constitutive TEF1 promoter were determined and compared. Both enzymes were dimeric and had temperature optima of 55°C with high substrate specificity for guanine and localisation in both the cytoplasm and vacuole of yeast. The enzyme was demonstrated to reduce levels of guanine in food. A mixture of guanine deaminase and other purine degradation enzymes will allow the reduction of purines in purine-rich foods

    Arxula adeninivorans Recombinant Urate Oxidase and Its Application in the Production of Food with Low Uric Acid Content

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    Hyperuricemia and its symptoms are becoming increasingly common worldwide. Elevated serum uric acid levels are caused by increased uric acid synthesis from food constituents and reduced renal excretion. Treatment in most cases involves reducing alcohol intake and consumption of meat and fish or treatment with pharmaceuticals. Another approach could be to reduce uric acid level in food, either during production or consumption. This work reports the production of recombinant urate oxidase by Arxula adeninivorans and its application to reduce uric acid in a food product. The A. adeninivorans urate oxidase amino acid sequence was found to be similar to urate oxidases from other fungi (61-65% identity). In media supplemented with adenine, hypoxanthine or uric acid, induction of the urate oxidase (AUOX) gene and intracellular accumulation of urate oxidase (Auoxp) was observed. The enzyme characteristics were analyzed from isolates of the wild-type strain A. adeninivorans LS3, as well as from those of transgenic strains expressing the AUOX gene under control of the strong constitutive TEF1 promoter or the inducible AYNI1 promoter. The enzyme showed high substrate specificity for uric acid, a broad temperature and pH range, high thermostability and the ability to reduce uric acid content in food

    Vision-related fitness to drive mobility scooters:A practical driving test

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    Objective: To investigate practical fitness to drive mobility scooters, comparing visually impaired participants with healthy controls. Design: Between-subjects design. Subjects: Forty-six visually impaired (13 with very low visual acuity, 10 with low visual acuity, 11 with peripheral field defects, 12 with multiple visual impairment) and 35 normal-sighted controls. Methods: Participants completed a practical mobility scooter test-drive, which was recorded on video. Two independent occupational therapists specialized in orientation and mobility evaluated the videos systematically. Results: Approximately 90% of the visually impaired participants passed the driving test. On average, participants with visual impairments performed worse than normal-sighted controls, but were judged sufficiently safe. In particular, difficulties were observed in participants with peripheral visual field defects and those with a combination of low visual acuity and visual field defects. Conclusion: People with visual impairment are, in practice, fit to drive mobility scooters; thus visual impairment on its own should not be viewed as a determinant of safety to drive mobility scooters. However, special attention should be paid to individuals with visual field defects with or without a combined low visual acuity. The use of an individual practical fitness-to-drive test is advised

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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