149 research outputs found
Shape Memory Alloy Reinforced Concrete Frames Vulnerable to Strong Vertical Excitations
Reinforced concrete (RC) framed buildings dissipate the seismic energy through yielding of the reinforcing bars. This yielding jeopardizes the serviceability of these buildings as it results in residual lateral deformations. Superelastic shape memory alloys (SMAs) can recover inelastic strains by stress removal. This paper extends previous research by the authors that optimized the use of SMA bars in RC frames considering the horizontal seismic excitation by addressing the effect of the vertical seismic excitation. A steel RC six-storey building designed according to current seismic standards is considered as case study. Five different earthquake records with strong vertical components are selected for the nonlinear dynamic analysis. The results were used to evaluate the effect of the vertical excitation on the optimum locations of SMA bars
Hydrologic responses of the Zwalm catchment using the REW model: incorporating uncertainty of soil properties
International audienceThe research presented in this paper focuses on an application of a newly developed physically-based watershed model approach, which is called Representative Elementary Watershed (REW) approach. The study stressed the effects of uncertainty of input parameters on the watershed responses (i.e. simulated discharges). The approach was applied to the Zwalm catchment, which is an agriculture dominated watershed with a drainage area of 114.3 km2 located in East-Flanders, Belgium. Uncertainty analysis of the model parameters is limited to the saturated hydraulic conductivity because of its high influence on the watershed hydrologic behavior. The assessment of outputs uncertainty is performed using the Monte Carlo method. The ensemble statistical watershed responses and their uncertainties are calculated and compared with the measurements. The results show that the measured discharges are falling within the 95% confidence interval of the modeled discharge
Detection of contaminant plumes released from landfills
International audienceContaminant leaks released from landfills are a significant threat to groundwater quality. The groundwater detection monitoring systems installed in the vicinity of such facilities are vital. In this study the detection probability of a contaminant plume released from a landfill has been investigated by means of both a simulation and an analytical model for both homogeneous and heterogeneous aquifer conditions. The results of the two models are compared for homogeneous aquifer conditions to illustrate the errors that might be encountered with the simulation model. For heterogeneous aquifer conditions contaminant transport is modelled by an analytical model using effective (macro) dispersivities. The results of the analysis show that the simulation model gives the concentration values correctly over most of the plume length for homogeneous aquifer conditions, and that the detection probability of a contaminant plume at given monitoring well locations match quite well. For heterogeneous aquifer conditions the approximating analytical model based on effective (macro) dispersivities yields the average concentration distribution satisfactorily. However, it is insufficient in monitoring system design since the discrepancy between the detection probabilities of contaminant plumes at given monitoring well locations computed by the two models is significant, particularly with high dispersivity and heterogeneity
COVID-19 Outbreak: Effect of an Educational Intervention Based on Health Belief Model on Nursing Students' Awareness and Health Beliefs at Najran University, Kingdom of Saudi Arabia
This study aimed to investigate the effect of an educational intervention based on the health belief model (HBM) about COVID-19 on nursing students' awareness and health beliefs. A true-experimental research design was conducted at nursing college, Najran University, KSA. A comprehensive sampling was followed to include all female students at the colleges (164 students). The sample was divided randomly into intervention (82) and control group (82). The educational intervention was designed and conducted based on the HBM through four sequential phases: assessment, planning, implementation, and evaluation. The current study results indicated no statistically significant differences between intervention and control groups concerning their demographic characteristic, awareness, and health beliefs before intervention. After intervention, significant differences (p< 0.05) were observed between intervention and control groups in their awareness and all HBM constructs regarding COVID19. There were positive, statistically significant correlations (P< 0.05) between participants' total HBM score and their total awareness score. This study concluded that HBM is effective in increasing nursing students' awareness regarding COVID-19. It also increases their perceived susceptibility, severity, and benefits. Besides, it may increase their self-efficacy to overcome perceived barriers to practice protective and preventive actions while dealing with COVID-19.
Keywords: Awareness, COVID-19, Health belief model, Nursing students, Saudi Arabia
Cette étude visait à étudier l'effet d'une intervention éducative basée sur le modèle de croyance en santé (HBM) à propos du COVID-19 sur la sensibilisation des étudiants en soins infirmiers et leurs croyances en matière de santé. Une conception de recherche véritablement expérimentale a été menée au collège d'infirmières de l'Université de Najran, en Arabie Saoudite. Un échantillonnage complet a été suivi pour inclure toutes les étudiantes des collèges (164 étudiantes). L'échantillon a été divisé au hasard en groupe d'intervention (82) et groupe témoin (82). L'intervention éducative a été conçue et menée sur la base du HBM à travers quatre phases séquentielles: évaluation, planification, mise en oeuvre et évaluation. Les résultats de l'étude actuelle n'ont indiqué aucune différence statistiquement significative entre les groupes d'intervention et de contrôle concernant leurs caractéristiques démographiques, leur sensibilisation et leurs croyances en matière de santé avant l'intervention. Aprèsl'intervention, des différences significatives (p <0,05) ont été observées entre les groupes d'intervention et de contrôle dans leur connaissance et tutes les constructions HBM concernant COVID19. Il y avait des corrélations positives et statistiquement significatives (P <0,05) entre le score HBM total des participants et leur score total de sensibilisation. Cette étude a conclu que HBM est efficace pour sensibiliser les étudiants en sciences infirmières au COVID-19. Cela augmente également leur sensibilité, leur gravité et leurs avantages perçus. En outre, cela peut augmenter leur efficacité personnelle pour surmonter les obstacles perçus à la pratique d'actions de protection et de prévention tout en traitant le COVID-19.
Mots-clés: Sensibilisation, COVID-19, modèle de croyance en matière de santé, étudiants en sciences infirmières, Arabie saoudit
A decision analysis approach for optimal groundwater monitoring system design under uncertainty
International audienceGroundwater contamination is the degradation of the natural quality of groundwater as a result of human activity. Landfills are one of the most common human activities threatening the groundwater quality. The objective of the monitoring systems is to detect the contaminant plumes before reaching the regulatory compliance boundary in order to prevent the severe risk to both society and groundwater quality, and also to enable cost-effective counter measures in case of a failure. The detection monitoring problem typically has a multi-objective nature. A multi-objective decision model (called MONIDAM) which links a classic decision analysis approach with a stochastic simulation model is applied to determine the optimal groundwater monitoring system given uncertainties due to the hydrogeological conditions and contaminant source characteristics. A Monte Carlo approach is used to incorporate uncertainties. Hydraulic conductivity and the leak location are the random inputs of the simulation model. The design objectives considered in the model are: (1) maximizing the detection probability, (2) minimizing the contaminated area and, (3) minimize the total cost of the monitoring system. The results show that the monitoring systems located close to the source are optimal except for the cases with very high unit installation and sampling cost and/or very cheap unit remediation cost
Cap-Assisted Technique versus Conventional Methods for Esophageal Food Bolus Extraction: A Comparative Study
Background/Aims Food bolus impaction is the most common form of esophageal foreign body impaction observed in adults. Clinical guidelines recommend using the push technique or retrieval methods in such cases. The push technique can cause injuries in certain clinical situations. Notably, conventional retrieval methods are time and effort consuming. Cap-assisted endoscopic extraction of an impacted food bolus is an easy and effective technique; however, more data are needed for its validation. This study compared the capassisted extraction technique with conventional methods. Methods This prospective observational multicenter study compared the success and en bloc removal rates, total procedure time, and adverse events in both techniques.. Results The study included 303 patients who underwent food bolus extraction. The push technique was used in 87 patients (28.7%) and a retrieval procedure in 216 patients (71.3%). Cap-assisted extraction was performed in 106 patients and retrieval using conventional methods in 110 patients. The cap-assisted technique was associated with a higher rate of en bloc removal (80.2% vs. 15%, p<0.01), shorter procedure time (6.9±3.5 min vs. 15.7±4.1 min, p<0.001), and fewer adverse events (0/106 vs. 9/110, p<0.001). Conclusions Cap-assisted extraction showed no adverse events, higher efficacy, and a shorter procedure time compared with conventional retrieval procedures
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Biological Treatment and the Potential Risk of Adverse Postoperative Outcome in Patients With Inflammatory Bowel Disease: An Open-Source Expert Panel Review of the Current Literature and Future Perspectives
Abstract
Background
There is widespread concern that treatment with biologic agents may be associated with suboptimal postoperative outcome after surgery for inflammatory bowel diseases (IBD).
Aim
We aimed to search and analyze the literature regarding the potential association of biologic treatment on adverse postoperative outcome in patients with IBD. We used the subject as a case in point for surgical research. The aim was not to conduct a new systematic review.
Method
This is an updated narrative review written in a collaborative method by authors invited through Twitter via the following hashtags (#OpenSourceResearch and #SoMe4Surgery). The manuscript was presented as slides on Twitter to allow discussion of each section of the paper sequentially. A Google document was created, which was shared across social media, and comments and edits were verified by the primary author to ensure accuracy and consistency.
Results
Forty-one collaborators responded to the invitation, and a total of 106 studies were identified that investigated the potential association of preoperative biological treatment on postoperative outcome in patients with IBD. Most of these studies were retrospective observational cohorts: 3 were prospective, 4 experimental, and 3 population-based studies. These studies were previously analyzed in 10 systematic/narrative reviews and 14 meta-analyses. Type of biologic agents, dose, drug concentration, antidrug antibodies, interval between last dose, and types of surgery varied widely among the studies. Adjustment for confounders and bias control ranged from good to very poor. Only 10 studies reported postoperative outcome according to Clavien–Dindo classification.
Conclusion
Although a large number of studies investigated the potential effect of biological treatment on postoperative outcomes, many reported divergent results. There is a need for randomized controlled trials. Future studies should focus on the avoiding the weakness of prior studies we identified. Seeking collaborators and sharing information via Twitter was integral to widening the contributors/authors and peer review for this article and was an effective method of collaboration
- …