Compensatory behaviour of visually impaired cyclists in everyday settings

This study investigated whether visually impaired cyclists, compared to cyclists without visual limitations, take other, potentially safer routes to destinations in their own living environment and whether they ride at a lower speed. In total, 19 matched pairs of a visually impaired cyclist and a normally sighted peer from the same neighbourhood recorded their everyday bicycle rides, using GPS action cameras. In addition, they completed an 'assigned ride', a ride for which only a starting and an ending point were provided by the researcher. A risk-assessment procedure showed that the route taken by visually impaired cyclists during this assigned ride was not less risky than the route taken by the normally sighted cyclists. Analysis of the everyday rides showed that, on average, cyclists with a visual impairment more frequently (i.e. for longer periods) cycled at a speed below 10 km/h compared to cyclists without visual impairment. Also, the visually impaired participants' cruising speed was 1.4 km/h lower than that of their normally sighted counterparts. In conclusion, no evidence was found that visually impaired cyclists compensate strategically by taking different, potentially safer routes than normally sighted cyclists when riding in their own environment. They may (unconsciously) compensate tactically for their visual function limitations by riding at a lower speed when necessary. Mobility trainers in vision rehabilitation as well as road designers could apply these findings to optimise the cycling mobility of visually impaired people

How visually impaired cyclists ride regular and pedal electric bicycles

The present study investigates whether visually impaired cyclists compensate for their vision limitations by maintaining a lower speed or a larger distance to the kerb than normally sighted cyclists when riding a regular bicycle or pedal electric bicycle (pedelec). A normally sighted control group (n = 10), a peripheral visual field loss group (n = 9), and a low visual acuity group (n = 12) rode a fixed route (7.5 km) in the Netherlands on a regular bicycle and on a pedelec. Speed and lateral position were measured when participants cycled a (I) one-way cycle path, (II) two-way cycle path, (III) residential area, and (IV) shared space zone. With regard to both the regular bicycle and the pedelec, no significant speed or lateral position differences were found between the three groups. In conclusion, for some people with severe and permanent visual impairments, and under certain circumstances, regular bicycle and pedelec riding may be possible without noticeable speed reduction or adapted lane position to compensate for their functional impairment. The present findings may further optimise the cycling advice provided by mobility trainers of vision rehabilitation centres and the independent mobility of visually impaired people

Car Driving Performance in Hemianopia:An On-Road Driving Study

PURPOSE. To study driving performance in people with homonymous hemianopia (HH) assessed in the official on-road test of practical fitness to drive by the Dutch driver's licensing authority (CBR).METHODS. Data were collected from a cohort (January 2010-July 2012) of all people with HH following the official relicensure trajectory at Royal Dutch Visio and the CBR in the Netherlands. Driving performance during the official on-road tests of practical fitness to drive was scored by professional experts on practical fitness to drive, using the visual impairments protocol and a standardized scoring of visual, tactical and operational aspects. Age ranged from 27 to 72 years (mean = 52, SD = 11.7) and time since onset of the visual field defect ranged from 6 to 41 months (mean = 15, SD = 7.5).RESULTS. Fourteen (54%) participants were judged as fit to drive. Besides poor visual scanning during driving, specific tactical, and operational weaknesses were observed in people with HH that were evaluated as unfit to drive. Results suggest that judgement on practical fitness to drive cannot be based on solely the visual field size. Visual scanning and operational handling of the car were found to be more impaired with longer time not driven, while such an effect was not found for tactical choices during driving.CONCLUSIONS. Training programs aimed at improving practical fitness to drive in people with HH should focus on improving both visual scanning, as well as driving aspects such as steering stability, speed adaptation, and anticipating environmental changes.</p

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

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

Оцінювання зволоженості гірських водозборів при математичному моделюванні дощових паводків

Розроблено процедуру оцінювання зволоженості водозбору, яка не потребує тривалого моделювання в оперативних умовах.Разработана процедура оценивания увлажненности водосбора, которая исключает необходимость продолжительного моделирования в оперативных условиях

The effect of chronic kidney disease on tissue formation of in situ tissue-engineered vascular grafts

Vascular in situ tissue engineering encompasses a single-step approach with a wide adaptive potential and true off-the-shelf availability for vascular grafts. However, a synchronized balance between breakdown of the scaffold material and neo-tissue formation is essential. Chronic kidney disease (CKD) may influence this balance, lowering the usability of these grafts for vascular access in end-stage CKD patients on dialysis. We aimed to investigate the effects of CKD on in vivo scaffold breakdown and tissue formation in grafts made of electrospun, modular, supramolecular polycarbonate with ureido-pyrimidinone moieties (PC-UPy). We implanted PC-UPy aortic interposition grafts (n = 40) in a rat 5/6th nephrectomy model that mimics systemic conditions in human CKD patients. We studied patency, mechanical stability, extracellular matrix (ECM) components, total cellularity, vascular tissue formation, and vascular calcification in CKD and healthy rats at 2, 4, 8, and 12 weeks post-implantation. Our study shows successful in vivo application of a slow-degrading small-diameter vascular graft that supports adequate in situ vascular tissue formation. Despite systemic inflammation associated with CKD, no influence of CKD on patency (Sham: 95% vs CKD: 100%), mechanical stability, ECM formation (Sirius red +, Sham 16.5% vs CKD 25.0%-p:0.83), tissue composition, and immune cell infiltration was found. We did find a limited increase in vascular calcification at 12 weeks (Sham 0.08% vs CKD 0.80%-p:0.02) in grafts implanted in CKD animals. However, this was not associated with increased stiffness in the explants. Our findings suggest that disease-specific graft design may not be necessary for use in CKD patients on dialysis. </p

Sustained Delivery of Insulin-Like Growth Factor-1/Hepatocyte Growth Factor Stimulates Endogenous Cardiac Repair in the Chronic Infarcted Pig Heart

Activation of endogenous cardiac stem/progenitor cells (eCSCs) can improve cardiac repair after acute myocardial infarction. We studied whether the in situ activation of eCSCs by insulin-like growth factor 1 (IGF-1) and hepatocyte growth factor (HGF) could be increased using a newly developed hydrogel in chronic myocardial infarction (MI). One-month post-MI pigs underwent NOGA-guided intramyocardial injections of IGF-1/HGF (GF: both 0.5 μg/mL, n = 5) or IGF-1/HGF incorporated in UPy hydrogel (UPy-GF; both 0.5 μg/mL, n = 5). UPy hydrogel without added growth factors was administered to four control (CTRL) pigs. Left ventricular ejection fraction was increased in the UPy-GF and GF animals compared to CTRLs. UPy-GF delivery reduced pathological hypertrophy, led to the formation of new, small cardiomyocytes, and increased capillarization. The eCSC population was increased almost fourfold in the border zone of the UPy-GF-treated hearts compared to CTRL hearts. These results show that IGF-1/HGF therapy led to an improved cardiac function in chronic MI and that effect size could be further increased by using UPy hydrogel. Electronic supplementary material The online version of this article (doi:10.1007/s12265-013-9518-4) contains supplementary material, which is available to authorized users

Distributed learning on 20 000+ lung cancer patients - The Personal Health Train

Background and purpose Access to healthcare data is indispensable for scientific progress and innovation. Sharing healthcare data is time-consuming and notoriously difficult due to privacy and regulatory concerns. The Personal Health Train (PHT) provides a privacy-by-design infrastructure connecting FAIR (Findable, Accessible, Interoperable, Reusable) data sources and allows distributed data analysis and machine learning. Patient data never leaves a healthcare institute. Materials and methods Lung cancer patient-specific databases (tumor staging and post-treatment survival information) of oncology departments were translated according to a FAIR data model and stored locally in a graph database. Software was installed locally to enable deployment of distributed machine learning algorithms via a central server. Algorithms (MATLAB, code and documentation publicly available) are patient privacy-preserving as only summary statistics and regression coefficients are exchanged with the central server. A logistic regression model to predict post-treatment two-year survival was trained and evaluated by receiver operating characteristic curves (ROC), root mean square prediction error (RMSE) and calibration plots. Results In 4 months, we connected databases with 23 203 patient cases across 8 healthcare institutes in 5 countries (Amsterdam, Cardiff, Maastricht, Manchester, Nijmegen, Rome, Rotterdam, Shanghai) using the PHT. Summary statistics were computed across databases. A distributed logistic regression model predicting post-treatment two-year survival was trained on 14 810 patients treated between 1978 and 2011 and validated on 8 393 patients treated between 2012 and 2015. Conclusion The PHT infrastructure demonstrably overcomes patient privacy barriers to healthcare data sharing and enables fast data analyses across multiple institutes from different countries with different regulatory regimens. This infrastructure promotes global evidence-based medicine while prioritizing patient privacy

Sustained Delivery of Insulin-Like Growth Factor-1/Hepatocyte Growth Factor Stimulates Endogenous Cardiac Repair in the Chronic Infarcted Pig Heart

Activation of endogenous cardiac stem/progenitor cells (eCSCs) can improve cardiac repair after acute myocardial infarction. We studied whether the in situ activation of eCSCs by insulin-like growth factor 1 (IGF-1) and hepatocyte growth factor (HGF) could be increased using a newly developed hydrogel in chronic myocardial infarction (MI). One-month post-MI pigs underwent NOGA-gu ided intramyocardial injec- tions of IGF-1/HGF (GF: both 0.5 μ g/mL, n =5) or IGF-1/HGF incorporated in UPy hydrogel (UPy-GF; both 0.5 μ g/mL, n =5). UPy hydrogel without added growth factors was administered to four control (CTRL) pigs. Left ve ntricular ejection fraction was increased in the UPy-GF and GF animals compared to CTRLs. UPy-GF delivery reduced pathological hypertrophy, led to the formation of new, small cardiomyocytes, and increased capillarization. The eCSC popula tion was increased almost four- fold in the border zone of the UPy-GF-treated hearts compared to CTRL hearts. These results show that IGF-1/HGF therapy led to an improved cardia c function in chronic MI and that effect size could be further increased by using UPy hydrogel

A Fast pH-Switchable and Self-Healing Supramolecular Hydrogel Carrier for Guided, Local Catheter Injection in the Infarcted Myocardium

Minimally invasive intervention strategies after myocardial infarction use state-of-the-art catheter systems that are able to combine mapping of the infarcted area with precise, local injection of drugs. To this end, catheter delivery of drugs that are not immediately pumped out of the heart is still challenging, and requires a carrier matrix that in the solution state can be injected through a long catheter, and instantaneously gelates at the site of injection. To address this unmet need, a pH-switchable supramolecular hydrogel is developed. The supramolecular hydrogel is switched into a liquid at pH > 8.5, with a viscosity low enough to enable passage through a 1-m long catheter while rapidly forming a hydrogel in contact with tissue. The hydrogel has self-healing properties taking care of adjustment to the injection site. Growth factors are delivered from the hydrogel thereby clearly showing a reduction of infarct scar in a pig myocardial infarction model