368 research outputs found
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
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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
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
COVID-19 in a Dutch Nursing Home: A Longitudinal Retrospective Care-Home-Level Case Study on Infection Rate, Survival Rate, and Daily Functioning.
During the pandemic, nursing homes in the Netherlands were heavily affected by COVID-19. This study assesses the impact of COVID-19 on infection rate, survival rate, and daily functioning over the course of two years among residents of a nursing home in the Netherlands that was amongst the first nursing homes to be affected by the pandemic. This retrospective study followed 70 residents during a two-year period, starting in March 2020. Data were collected on baseline characteristics of participants and the onset, duration, and sequelae of COVID-19 infections. Primary outcomes were mortality and infection rate. The secondary outcome was daily functioning using the Barthel Index at intervals of six months. Within two years, 44 (62.9%) residents were diagnosed with COVID-19. During this study, 72.7% (n = 32) of the COVID-positive residents died, of which 22 deaths were related to the COVID-19 infection. Overall mortality was 60% (n = 42), while COVID-related mortality was 31.4% (n = 22). COVID-19 and multimorbidity (>3 morbidities) were independent risk factors for mortality. Barthel Index scores showed no significant difference in daily functioning. Overall, a high COVID-19 infection rate was seen and was the most common cause of death. COVID-19 did not affect functional status over time
The placebo response rate in pharmacological trials in patients with irritable bowel syndrome: a systematic review and meta-analysis
Findings Between June 16, 2014, and July 28, 2017, 122 patients were eligible for screening and a total of 95 patients were randomly assigned to the infliximab-continued group (n=48) or the infliximab-discontinued group (n=47). 92 patients (n=46 for both groups) were included in the full analysis set. 37 (80.4% [95% CI 66.1-90.6]) of 46 patients in the infliximab-continued group and 25 (54.3% [39.0-69.1]) of 46 patients in the infliximab-discontinued group were in remission at week 48. The between-group difference was 26.1% (95% CI 7.7-44.5; p=0.0076) before adjustment and 27.3% (95% CI 8.0-44.1; p=0.0059) after adjustment for stratification factors. Eight (17%) of 48 patients in the infliximab-continued group and six (13%) of 47 in the infliximab-discontinued group developed adverse events (between-group difference 3.9% [95% CI -10.3 to 18.1]; p=0.59). In the infliximab-continued group, one patient had an infusion reaction and two patients had psoriatic skin lesions. Eight (66.7%, 95% CI 34.9-90.1) of the 12 patients in the infliximab-discontinuation group who were re-treated with infliximab after relapsing were in remission within 8 weeks of re-treatment; none had infusion reactions.Background Anti-tumour necrosis factor (TNF) agents are the mainstay of long-term treatment for refractory ulcerative colitis. However, long-term use of anti-TNF therapy might lead to an increased risk of malignancy or infection. To date, no randomised controlled trial has evaluated whether anti-TNF agents can be safely discontinued in patients with ulcerative colitis in remission. We therefore aimed to compare outcomes in these patients who continued infliximab with those who discontinued infliximab.Methods We did a multicentre, open-label randomised controlled trial at 24 specialist centres in Japan. We enrolled patients with ulcerative colitis who were in remission, had been treated with intravenous infliximab (5 mg/kg) every 8 weeks, and had started infliximab at least 14 weeks before study enrolment. No restrictions regarding age and comorbidities were used to exclude participation. Patients who were confirmed to be in remission for more than 6 months, to be corticosteroid-free, and to have a Mayo Endoscopic Subscore (MES) of 0 or 1 were centrally randomised. An independent organisation randomly assigned patients (1:1) into either the infliximab-continued group or infliximab-discontinued group, using a computer-generated stratified randomisation procedure. The stratified factors were the use of immunomodulators (yes or no) and MES (0 or 1). Neither patients nor health-care providers were masked to the randomisation. The primary endpoint was the remission rate at week 48 in the full analysis set, which was based on the intention-to-treat principle and excluded participants with no efficacy data after randomisation. This study was registered with the University Hospital Medical Information Network Center Trials registry, UMIN000012092. Findings Between June 16, 2014, and July 28, 2017, 122 patients were eligible for screening and a total of 95 patients were randomly assigned to the infliximab-continued group (n=48) or the infliximab-discontinued group (n=47). 92 patients (n=46 for both groups) were included in the full analysis set. 37 (80.4% [95% CI 66.1-90.6]) of 46 patients in the infliximab-continued group and 25 (54.3% [39.0-69.1]) of 46 patients in the infliximab-discontinued group were in remission at week 48. The between-group difference was 26.1% (95% CI 7.7-44.5; p=0.0076) before adjustment and 27.3% (95% CI 8.0-44.1; p=0.0059) after adjustment for stratification factors. Eight (17%) of 48 patients in the infliximab-continued group and six (13%) of 47 in the infliximab-discontinued group developed adverse events (between-group difference 3.9% [95% CI & minus;10.3 to 18.1]; p=0.59). In the infliximab-continued group, one patient had an infusion reaction and two patients had psoriatic skin lesions. Eight (66.7%, 95% CI 34.9-90.1) of the 12 patients in the infliximab-discontinuation group who were re-treated with infliximab after relapsing were in remission within 8 weeks of re-treatment; none had infusion reactions.Interpretation Maintenance of remission was significantly more common in patients who continued infliximab than in those who discontinued. Discontinuing infliximab should therefore be discussed with caution, taking both risk of relapse and efficacy of re-treatment into account.Funding Mitsubishi Tanabe Pharma Corporation and the Intractable Disease Project of the Ministry of Health, Labour and Welfare of Japan.Copyright (c) 2021 Elsevier Ltd. All rights reserved
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
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 -80��C 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 ��g/mg wet wt). Low starch had higher glycogen concentration 24 h post (P = 0.04) than HS (9.52 vs. 7.68 ��g/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
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