New insights into pedestrian flow through bottlenecks

Capacity estimation is an important tool for the design and dimensioning of pedestrian facilities. The literature contains different procedures and specifications which show considerable differences with respect to the estimated flow values. Moreover do new experimental data indicate a stepwise growing of the capacity with the width and thus challenge the validity of the specific flow concept. To resolve these differences we have studied experimentally the unidirectional pedestrian flow through bottlenecks under laboratory conditions. The time development of quantities like individual velocities, density and individual time gaps in bottlenecks of different width is presented. The data show a linear growth of the flow with the width. The comparison of the results with experimental data of other authors indicates that the basic assumption of the capacity estimation for bottlenecks has to be revised. In contradiction with most planning guidelines our main result is, that a jam occurs even if the incoming flow does not overstep the capacity defined by the maximum of the flow according to the fundamental diagram.Comment: Traffic flow, pedestrian traffic, crowd dynamics, capacity of bottlenecks (16 pages, 8 figures); (+ 3 new figures and minor revisions

Perinatal insults and neurodevelopmental disorders may impact Huntington's disease age of diagnosis

Introduction: The age of diagnosis of Huntington's disease (HD) varies among individuals with the same HTT CAG-repeat expansion size. We investigated whether early-life events, like perinatal insults or neurodevelopmental disorders, influence the diagnosis age. Methods: We used data from 13,856 participants from REGISTRY and Enroll-HD, two large international multicenter observational studies. Disease-free survival analyses of mutation carriers with an HTT CAG repeat expansion size above and including 36 were computed through Kaplan-Meier estimates of median time until an HD diagnosis. Comparisons between groups were computed using a Cox proportional hazard survival model adjusted for CAG-repeat expansion length. We also assessed whether the group effect depended on gender and the affected parent. Results: Insults in the perinatal period were associated with an earlier median age of diagnosis of 45.00 years (95%CI: 42.07–47.92) compared to 51.00 years (95%CI: 50.68–51.31) in the reference group, with a CAG-adjusted hazard ratio of 1.61 (95%CI: 1.26–2.06). Neurodevelopmental disorders were also associated with an earlier median age of diagnosis than the reference group of 47.00 years (95% CI: 43.38–50.62) with a CAG-adjusted hazard ratio of 1.42 (95%CI: 1.16–1.75). These associations did not change significantly with gender or affected parent. Conclusions: These results, derived from large observational datasets, show that perinatal insults and neurodevelopmental disorders are associated with earlier ages of diagnosis of magnitudes similar to the effects of known genetic modifiers of HD. Given their clear temporal separation, these early events may be causative of earlier HD onset, but further research is needed to prove causation

A randomised controlled trial testing a web-based, computer-tailored self-management intervention for people with or at risk for chronic obstructive pulmonary disease: a study protocol

Contains fulltext : 125231.pdf (publisher's version ) (Open Access)BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) is a major cause of morbidity and mortality. Effective self-management support interventions are needed to improve the health and functional status of people with COPD or at risk for COPD. Computer-tailored technology could be an effective way to provide this support. METHODS/DESIGN: This paper presents the protocol of a randomised controlled trial testing the effectiveness of a web-based, computer-tailored self-management intervention to change health behaviours of people with or at risk for COPD. An intervention group will be compared to a usual care control group, in which the intervention group will receive a web-based, computer-tailored self-management intervention. Participants will be recruited from an online panel and through general practices. Outcomes will be measured at baseline and at 6 months. The primary outcomes will be smoking behaviour, measuring the 7-day point prevalence abstinence and physical activity, measured in minutes. Secondary outcomes will include dyspnoea score, quality of life, stages of change, intention to change behaviour and alternative smoking behaviour measures, including current smoking behaviour, 24-hour point prevalence abstinence, prolonged abstinence, continued abstinence and number of quit attempts. DISCUSSION: To the best of our knowledge, this will be the first randomised controlled trial to test the effectiveness of a web-based, computer-tailored self-management intervention for people with or at risk for COPD. The results will be important to explore the possible benefits of computer-tailored interventions for the self-management of people with or at risk for COPD and potentially other chronic health conditions. DUTCH TRIAL REGISTER: NTR3421

Early neurologically-focused follow-up after cardiac arrest improves quality of life at one year: A randomised controlled trial

Background: Survivors of a cardiac arrest frequently have cognitive and emotional problems and their quality of life is at risk. We developed a brief nursing intervention to detect cognitive and emotional problems, provide information and support, promote self-management, and refer them to specialised care if necessary. This study examined its effectiveness. Methods: Multicentre randomised controlled trial with measurements at two weeks, three months and twelve months after cardiac arrest. 185 adult cardiac arrest survivors and 155 caregivers participated. Primary outcome measures were societal participation and quality of life of the survivors at one year. Secondary outcomes were the patient's cognitive functioning, emotional state, extended daily activities and return to work, and the caregiver's well-being. Data were analysed using 'intention to treat' linear mixed model analyses. Results: After one year, patients in the intervention group had a significantly better quality of life on SF-36 domains Role Emotional (estimated mean differences (EMD) = 16.38, p = 0.006), Mental Health (EMD = 6.87, p = 0.003) and General Health (EMD = 8.07, p = 0.010), but there was no significant difference with regard to societal participation. On the secondary outcome measures, survivors scored significantly better on overall emotional state (HADS total, EMD = -3.25, p = 0.002) and anxiety (HADS anxiety, EMD = -1.79, p = 0.001) at one year. Furthermore, at three months more people were back at work (50% versus 21%, p = 0.006). No significant differences were found for caregiver outcomes. Conclusion: The outcomes of cardiac arrest survivors can be improved by an intervention focused on detecting and managing the cognitive and emotional consequences of a cardiac arrest. Trial registration: Current controlled trials, ISRCTN74835019. (C) 2015 Elsevier Ireland Ltd. All rights reserved

Perinatal insults and neurodevelopmental disorders may impact Huntington's disease age of diagnosis

INTRODUCTION: The age of diagnosis of Huntington's disease (HD) varies among individuals with the same HTT CAG repeat expansion size. We investigated whether early-life events, like perinatal insults or neurodevelopmental disorders, influence the diagnosis age. METHODS: We used data from 13,856 participants from REGISTRY and Enroll-HD, two large international multicenter observational studies. Disease-free survival analyses of mutation carriers with an HTT CAG repeat expansion size above and including 36 were computed through Kaplan-Meier estimates of median time until an HD diagnosis. Comparisons between groups were computed using a Cox proportional hazard survival model adjusted for CAG-repeat expansion length. We also assessed whether the group effect depended on gender and the affected parent. RESULTS: Insults in the perinatal period were associated with an earlier median age of diagnosis of 45.00 years (95%CI: 42.07–47.92) compared to 51.00 years (95%CI: 50.68–51.31) in the reference group, with a CAG-adjusted hazard ratio of 1.61 (95%CI: 1.26–2.06). Neurodevelopmental disorders were also associated with an earlier median age of diagnosis than the reference group of 47.00 years (95% CI: 43.38–50.62) with a CAG-adjusted hazard ratio of 1.42 (95%CI: 1.16–1.75). These associations did not change significantly with gender or affected parent. CONCLUSIONS: These results, derived from large observational datasets, show that perinatal insults and neurodevelopmental disorders are associated with earlier ages of diagnosis of magnitudes similar to the effects of known genetic modifiers of HD. Given their clear temporal separation, these early events may be causative of earlier HD onset, but further research is needed to prove causation

An illness-focused interactive booklet to optimise management and medication for childhood fever and infections in out-of-hours primary care: Study protocol for a cluster randomised trial

Background: Fever is the most common reason for a child to be taken to a general practitioner (GP), especially during out-of-hours care. It is mostly caused by self-limiting infections. However, antibiotic prescription rates remain high, especially during out-of-hours care. Anxiety and lack of knowledge among parents, and perceived pressure to prescribe antibiotics amongst GPs, are important determinants of excessive antibiotic prescriptions. An illness-focused interactive booklet has the potential to improve this by providing parents with information about fever self-management strategies. The aim of this study is to develop and determine the effectiveness of an interactive booklet on management of children presenting with fever at Dutch GP out-of-hours cooperatives. Methods/design: We are conducting a cluster randomised controlled trial (RCT) with 20 GP out-of-hours cooperatives randomised to 1 of 2 arms: GP access to the illness-focused interactive booklet or care as usual. GPs working at intervention sites will have access to the booklet, which was developed in a multistage process. It consists of a traffic light system for parents on how to respond to fever-related symptoms, as well as information on natural course of infections, benefits and harms of (antibiotic) medications, self-management strategies and 'safety net' instructions. Children < 12 years of age with parent-reported or physician-measured fever are eligible for inclusion. The primary outcome is antibiotic prescribing during the initial consultation. Secondary outcomes are (intention to) (re)consult, antibiotic prescriptions during re-consultations, referrals, parental satisfaction and reassurance. In 6 months, 20,000 children will be recruited to find a difference in antibiotic prescribing rates of 25% in the control group and 19% in the intervention group. Statistical analysis will be performed using descriptive statistics and by fitting two-level (GP out-of-hours cooperative and patient) random intercept logistic regression models. Discussion: This will be the first and largest cluster RCT evaluating the effectiveness of an illness-focused interactive booklet during GP out-of-hours consultations with febrile children receiving antibiotic prescriptions. It is hypothesised that use of the booklet will result in a reduced number of antibiotic prescriptions, improved parental satisfaction and reduced intention to re-consult. Trial registration: ClinicalTrials.gov identifier: NCT02594553. Registered on 26 Oct 2015, last updated 15 Sept 2016

Factors associated with smoking initiation among Saudi male adolescents: A longitudinal study

© 2019 The Athors. Introduction: Knowing country-specific predictors of smoking behaviour for adolescents is crucial for successful smoking prevention programs. This study aims to assess demographic and socio-cognitive variables related to smoking initiation among Saudi male adolescents. Methods: Longitudinal data were collected at T1 (baseline) and at T2 (followup at 6 months) using a self-administered questionnaire. We assessed smoking behaviour and related demographic variables and socio-cognitive variables. Chisquared tests and independent-samples t-tests were used to identify differences in baseline characteristics between smokers and non-smokers at T1. Furthermore, non-smokers at T1 were included in logistic regression analyses to examine the predictors of smoking initiation between T1 and T2. Results: At T1, the non-smokers who were included in further analysis were 523 (84.9%) of whom 48 (9.2%) had initiated smoking at T2. They differed significantly from non-initiators, including having a more positive attitude towards smoking, reporting more social norms, modelling and pressure to smoke, having a lower self-efficacy to refrain from smoking and higher intention to smoke in the future (all p<0.001). The regression analysis revealed that: adolescents with disrupted-families, being of low academic achievement, with relatively high monthly-income families, having more smoking-peers, high-perceived pressure to smoke from parents (p=0.002) and teachers (p=0.001), have smoking supportivenorms of parents and having high intention to smoke in the future (p<0.001) were at higher risk of being smokers. Conclusions: Findings suggest that health-promoting programs should address strengthening of self-efficacy and enhancing refusal skills against modelling of peers, pressure and norms of parents

Optical diagnosis of colorectal polyp images using a newly developed computer-aided diagnosis system (CADx) compared with intuitive optical diagnosis

Background Optical diagnosis of colorectal polyps remains challenging. Image-enhancement techniques such as narrow-band imaging and blue-light imaging (BLI) can improve optical diagnosis. We developed and prospectively validated a computer-aided diagnosis system (CADx) using high-definition white-light (HDWL) and BLI images, and compared the system with the optical diagnosis of expert and novice endoscopists.Methods CADx characterized colorectal polyps by exploiting artificial neural networks. Six experts and 13 novices optically diagnosed 60 colorectal polyps based on intuition. After 4 weeks, the same set of images was permuted and optically diagnosed using the BLI Adenoma Serrated International Classification (BASIC).Results CADx had a diagnostic accuracy of 88.3% using HDWL images and 86.7% using BLI images. The overall diagnostic accuracy combining HDWL and BLI (multimodal imaging) was 95.0%, which was significantly higher than that of experts (81.7%, P =0.03) and novices (66.7%, P <0.001). Sensitivity was also higher for CADx (95.6% vs. 61.1% and 55.4%), whereas specificity was higher for experts compared with CADx and novices (95.6% vs. 93.3% and 93.2%). For endoscopists, diagnostic accuracy did not increase when using BASIC, either for experts (intuition 79.5% vs. BASIC 81.7%, P =0.14) or for novices (intuition 66.7% vs. BASIC 66.5%, P =0.95).Conclusion CADx had a significantly higher diagnostic accuracy than experts and novices for the optical diagnosis of colorectal polyps. Multimodal imaging, incorporating both HDWL and BLI, improved the diagnostic accuracy of CADx. BASIC did not increase the diagnostic accuracy of endoscopists compared with intuitive optical diagnosis

The Effect of Various Levels of Dietary Starch on Glycogen Replenishment in the Light Working Horse

Nine Quarter Horses (2 to 7 yr; 409 to 494 kg BW) were used in a 3 x 3 Latin square with replication study lasting 105 d to determine the effect of various levels of dietary starch on glycogen replenishment in the light working horse. Horses were fed 1 % BW/d in Coastal Bermudagrass hay with remaining calories met by a high starch (HS), medium starch (MS), or low starch (LS) concentrate. After a 7 d washout period, horses were transitioned to 1 of the 3 diets over 7 d for a 14 d treatment period where they were then worked to fatigue in a standardized exercise test (SET). Total diets provided an average of 1,206.67, 844.61, and 263.13 g of starch/d in HS, MS, and LS, respectively. Horses were lightly exercised for 30 min 3 d/wk. The SET consisted of a 30 min trot in a panel exerciser, followed by 27 min of an incremental high-intensity work on a treadmill. Skeletal muscle biopsies were taken from the biceps femoris at rest, immediately after the SET, and 24 and 48 h post exercise. Samples were submerged in liquid nitrogen and stored at -80ºC until glycogen analysis using a commercial kit. Venous blood samples were taken at rest, immediately post exercise, 10 min after recovery, and 24 h post exercise. Data was analyzed using Proc Mixed (SAS) program. High starch had higher resting muscle glycogen concentration (P = 0.009) than MS (10.25 vs. 8.28 μg/mg wet wt). Low starch had higher glycogen concentration 24 h post (P = 0.04) than HS (9.52 vs. 7.68 μg/mg wet wt). High starch utilized more glycogen than MS or LS. A slight reduction in glycogen post exercise for MS and LS indicated that fat or protein may have been used as substrate for exercise. Results indicated that feeding 1,206.67 g starch/d did not yield an advantage in recovery time over a MS or LS diet. Energy expenditure during the SET yielded similar (P = 0.98) blood lactate concentrations, resulting in the formation of a prediction equation of y = 0.002x^2 – 0.3102x + 6.6874