1,092 research outputs found

    Improving the visibility of bicycle infrastructure

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    The visual characteristics of road infrastructure play a major role in a substantial number of single-bicycle crashes. The focus of this research was on finding the most common situations that result in a poorly visible bicycle infrastructure, and investigating how to improve these conditions for vulnerable cyclist populations, specifically the visually impaired and the older cyclist. Three studies were performed, a questionnaire study amongst visually impaired cyclists, focus group discussions with older cyclists, and an experiment on a closed track where participants’ vision, in particular their contrast sensitivity, was impaired. The results from the questionnaire study and the focus group discussions revealed that bollards, kerbs, and cycle path markings/shoulders are the most critical visual elements in the road infrastructure. In addition, cycling performance and cyclists’ feelings of safety worsened in conditions where the visibility of obstacles and the road’s course were the poorest. Visibility can be enhanced by placing red-white bollards, painting kerbs white, by enhancing clearness of the road’s shoulder, or by applying high contrast road markings on the side of the cycle path/road

    Mobile phone use while cycling:Incidence and effects on behaviour and safety

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    The effects of mobile phone use on cycling behaviour were studied. In study 1, the prevalence of mobile phone use while cycling was assessed. In Groningen 2.2% of cyclists were observed talking on their phone and 0.6% were text messaging or entering a phone number. In study 2, accident-involved cyclists responded to a questionnaire. Only 0.5% stated that they were using their phone at the time of the accident. In study 3, participants used a phone while cycling. The content of the conversation was manipulated and participants also had to enter a text message. Data were compared with just cycling and cycling while listening to music. Telephoning coincided with reduced speed, reduced peripheral vision performance and increased risk and mental effort ratings. Text messaging had the largest negative impact on cycling performance. Higher mental workload and lower speed may account for the relatively low number of people calling involved in accidents. Statement of Relevance: Although perhaps mainly restricted to flat countries with a large proportion of cyclists, mobile phone use while cycling has increased and may be a threat to traffic safety, similar to phone use while driving a car. In this study, the extent of the problem was assessed by observing the proportion of cyclists using mobile phones, sending questionnaires to accident-involved cyclists and an experimental study was conducted on the effects of mobile phone use while cycling

    Iodine-131 in Household waste - a pilot study

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    Werknemers in de thuis- en verpleegzorg en vuilnisophalers komen soms zonder dat te weten in aanraking met de radioactieve stof jodium-131. Toch is het niet aannemelijk dat zij aan een te hoge stralingsdosis blootstaan. Voorwaarde is, dat ze de normale hygienische voorschriften naleven. Dit blijkt uit verkennend onderzoek van het RIVM. Aanleiding is een tiental stralingsmeldingen bij een afvalverbrandingsinstallatie voor huishoudelijk afval in Dordrecht tussen april 2008 en april 2009. De straling was afkomstig van jodium-131 in incontinentiemateriaal en ander afval van patienten die met deze radioactieve stof zijn behandeld wegens een schildklierafwijking. Voor het onderzoek zijn vijf ziekenhuizen bezocht en zijn gegevens van de VROM-Inspectie gebruikt. Op basis hiervan heeft het RIVM scenario's opgesteld waarmee dosisschattingen voor werknemers zijn gemaakt. Deze schattingen zijn gebaseerd op de veronderstelling dat de hoeveelheid jodium-131 in incontinentiemateriaal niet groter is dan tot nu toe in het huishoudelijk afval is waargenomen. Er zijn twee mogelijke verklaringen voor de aanwezigheid van jodium-131 in het incontinentiemateriaal. Incontinente patienten mogen in Nederland niet poliklinisch met jodium-131 worden behandeld, maar in de praktijk gebeurt dat toch. De eerste 24 uur na de behandeling bevat de urine van deze patienten relatief veel van deze radioactieve stof. Een tweede verklaring zou kunnen zijn dat patienten die met een hoge dosering zijn behandeld, in sommige ziekenhuizen vaker vervroegd worden ontslagen. In Duitsland is poliklinische behandeling met jodium-131 niet toegestaan. Gezien de beperkte risico's lijkt een dergelijk totaalverbod in Nederland niet te rechtvaardigen. Om de risico's voor derden laag te houden, zou men bij incontinente patienten terughoudend moeten zijn met poliklinische behandeling en vervroegd ontslag.Workers in homecare and nursing homes are occasionally exposed to the radioactive drug iodine-131. Still, it is unlikely that dose limits are exceeded, provided that sanitary procedures are followed. This is shown in a pilot study by RIVM carried out after a number of radiation alerts at the household waste incinerator in Dordrecht between April 2008 and April 2009. The radiation originated from iodine-131 in diapers and similar waste from patients that had been treated for thyroid disorders. For this pilot study, five hospitals have been visited, and data were obtained from the environmental inspectorate. Based on this, scenarios were drawn up and dose estimates were made for workers. Two explanations are given for the unexpected presence of iodine-131 in household waste. First iodine-131 therapy is not allowed for outpatients if they are incontinent, but it is still done. Second, early release of patients treated with high doses may occur more often in some hospitals. In Germany, iodine therapy of outpatients is not allowed at all. In view of the limited risks, such a total ban seems unjustifiable in the Netherlands. To keep the risks for others to a minimum, hospitals should exercise restraint on sending incontinent patients home early.VRO

    Identification of critical amino acids involved in ι1-β interaction in voltage-dependent Ca2+ channels

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    AbstractIn voltage-dependent Ca2+ channels, the ι1 and β subunits interact via two cytoplasmic regions defined as the Alpha Interaction Domain (AID) and Beta Interaction Domain (BID). Several novel amino acids for that interaction have now been mapped in both domains by point mutations. It was found that three of the nine amino acids in AID and four of the eight BID amino acids tested were essential for the interaction. Whereas the important AID amino acids were clustered around five residues, the important BID residues were more widely distributed within a larger 16 amino acid sequence. The affinity of the AIDA GST fusion protein for the four interacting β1b BID mutants was not significantly altered compared with the wild-type β1b despite the close localization of mutated residues to disruptive BID amino acids. Expression of these interactive β mutants with the full-length ι1A subunit only slightly modified the stimulation efficiency when compared with the wild-type β1b subunit. Our data suggest that non-disruptive BID sequence alterations do not dramatically affect the β subunit-induced current stimulation

    Pectin limits epithelial barrier disruption by Citrobacter rodentium through anti-microbial effects

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    SCOPE: C. rodentium is the murine equivalent of Enteropathogenic Escherichia. coli (EPEC) and Enterohemorrhagic Escherichia coli (EHEC) which induce damage to the intestinal epithelial barrier that results in diarrhea and intestinal inflammation. Dietary fibre intake can be an effective approach to limit epithelial damage by these enteric pathogens. Therefore, the protective effect of dietary fibre pectin against dysfunction of epithelial barrier integrity upon C. rodentium infection was investigated. METHODS AND RESULTS: Pectins that structurally differed in the degree and distribution of methylesters were tested on barrier protective effects on epithelial cells against C. rodentium by measuring transepithelial electrical resistance and lucifer yellow fluxes. All three pectins protected the epithelial barrier from C. rodentium induced damage in a structure-independent manner. These barrier protective effects were also independent of pectin-induced TLR2 activation. Furthermore, the pectins induced anti-adhesive effects on C. rodentium by interacting with C. rodentium and not with epithelial cells. This may be explained by antimicrobial effects of pectins on C. rodentium and not on other enteric bacteria including Lactobacillus plantarum and E. coli. A competition ELISA for binding of C. rodentium to pectin supported this finding as it showed that pectin interacts strongly with C. rodentium, whereas it interacts weakly or not with L. plantarum or E. coli. CONCLUSION: These findings demonstrate that pectin protects the epithelial barrier from C. rodentium induced damage by inducing anti-microbial effects
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