The Social context of motorcycle riding and the key determinants influencing rider behavior: A qualitative investigation

Objective: Given the increasing popularity of motorcycle riding and heightened risk of injury or death associated with being a rider, this study explored rider behaviour as a determinant of rider safety and, in particular, key beliefs and motivations which influence such behaviour. To enhance the effectiveness of future education and training interventions, it is important to understand riders’ own views about what influences how they ride. Specifically, this study sought to identify key determinants of riders’ behaviour in relation to the social context of riding including social and identity-related influences relating to the group (group norms and group identity) as well as the self (moral/personal norm and self-identity). ----- ----- Method: Qualitative research was undertaken via group discussions with motorcycle riders (n = 41). Results: The findings revealed that those in the group with which one rides represent an important source of social influence. Also, the motorcyclist (group) identity was associated with a range of beliefs, expectations, and behaviours considered to be normative. Exploration of the construct of personal norm revealed that riders were most cognizant of the “wrong things to do” when riding; among those issues raised was the importance of protective clothing (albeit for the protection of others and, in particular, pillion passengers). Finally, self-identity as a motorcyclist appeared to be important to a rider’s self-concept and was likely to influence their on-road behaviour. ----- ----- Conclusion: Overall, the insight provided by the current study may facilitate the development of interventions including rider training as well as public education and mass media messages. The findings suggest that these interventions should incorporate factors associated with the social nature of riding in order to best align it with some of the key beliefs and motivations underpinning riders’ on-road behaviours

Universal Prediction Distribution for Surrogate Models

International audienceThe use of surrogate models instead of computationally expensive simulation codes is very convenient in engineering. Roughly speaking, there are two kinds of surrogate models: the deterministic and the probabilistic ones. These last are generally based on Gaussian assumptions. The main advantage of probabilistic approach is that it provides a measure of uncertainty associated with the surrogate model in the whole space. This uncertainty is an efficient tool to construct strategies for various problems such as prediction enhancement, optimization or inversion.In this paper, we propose a universal method to define a measure of uncertainty suitable for any surrogate model either deterministic or probabilistic. It relies on Cross-Validation (CV) sub-models predictions. This empirical distribution may be computed in much more general frames than the Gaussian one. So that it is called the Universal Prediction distribution (UP distribution).It allows the definition of many sampling criteria. We give and study adaptive sampling techniques for global refinement and an extension of the so-called Efficient Global Optimization (EGO) algorithm. We also discuss the use of the UP distribution for inversion problems. The performances of these new algorithms are studied both on toys models and on an engineering design problem

Thoracic Epidural analgesia versus Rectus Sheath Catheters for open midline incisions in major abdominal surgery within an enhanced recovery programme (TERSC):study protocol for a randomised controlled trial

BACKGROUND: Thoracic epidural analgesia (TEA) is recommended for post-operative pain relief in patients undergoing major abdominal surgery via a midline incision. However, the effectiveness of TEA is variable with high failure rates reported post-operatively. Common side effects such as low blood pressure and motor block can reduce mobility and hinder recovery, and a number of rare but serious complications can also occur following their use.Rectus sheath catheters (RSC) may provide a novel alternative approach to somatic analgesia without the associated adverse effects of TEA. The aim of this study is to compare the efficacy of both techniques in terms of pain relief, patient experience, post-operative functional recovery, safety and cost-effectiveness. METHODS/DESIGN: This is a single-centre randomised controlled non-blinded trial, which also includes a nested qualitative study. Over a two-year period, 132 patients undergoing major abdominal surgery via a midline incision will be randomised to receive either TEA or RSC for post-operative analgesia. The primary outcome measures pain scores on moving from a supine to a sitting position at 24 hours post wound closure, and the patient experience between groups evaluated through in-depth interviews. Secondary outcomes include pain scores at rest and on movement at other time points, opiate consumption, functional recovery, morbidity and cost-effectiveness. DISCUSSION: This will be the first randomised controlled trial comparing thoracic epidurals to ultrasound-guided rectus sheath catheters in adults undergoing elective midline laparotomy. The standardised care provided by an Enhanced Recovery Programme makes this a comparison between two complex pain packages and not simply two analgesic techniques, in order to ascertain if RSC is a viable alternative to TEA. TRIAL REGISTRATION: Current Controlled Trials ISRCTN81223298 (16 January 2014)

Constraint Handling in Efficient Global Optimization

This is the author accepted manuscript. The final version is available from ACM via the DOI in this record.Real-world optimization problems are often subject to several constraints which are expensive to evaluate in terms of cost or time. Although a lot of effort is devoted to make use of surrogate models for expensive optimization tasks, not many strong surrogate-assisted algorithms can address the challenging constrained problems. Efficient Global Optimization (EGO) is a Kriging-based surrogate-assisted algorithm. It was originally proposed to address unconstrained problems and later was modified to solve constrained problems. However, these type of algorithms still suffer from several issues, mainly: (1) early stagnation, (2) problems with multiple active constraints and (3) frequent crashes. In this work, we introduce a new EGO-based algorithm which tries to overcome these common issues with Kriging optimization algorithms. We apply the proposed algorithm on problems with dimension d ≤ 4 from the G-function suite [16] and on an airfoil shape example.This research was partly funded by Tekes, the Finnish Funding Agency for Innovation (the DeCoMo project), and by the Engineering and Physical Sciences Research Council [grant numbers EP/N017195/1, EP/N017846/1]

Measurement of adsorption of a single component from the liquid phase : modelling investigation and sensitivity analysis

In this work, we consider an alternative approach for the measurement of adsorption from the liquid phase. Consider a mixture consisting of a non-adsorbed component (B) and an adsorbed component (A) present at some low concentration. Initially, a feed of component B only flows through a column packed with an adsorbent. Then, the feed is switched to the mixture of A and B. As soon as the mixture enters the column, there will be a reduction in the outlet flow rate as component A leaves the liquid phase and passes into the adsorbed phase. There are three stages to this work. The first is to develop overall and component balances to show how the amount adsorbed of component A can be determined from the variation in the column outlet flow rate. The second is to determine the actual variation in the column outlet flow rate for both plug flow and axial-dispersed plug flow. The final stage is to consider the suitability of a gravity-fed system to deliver the feed to the column. An analysis of the results shows that the experimental arrangement should be able to accurately monitor adsorption from the liquid phase where the mass fraction of the solute is of the order of 1%: the limiting experimental factor is how constant the volumetric flow rate of the liquid feed can be maintained

The aminopeptidase inhibitor CHR-2863 is an orally bioavailable inhibitor of murine malaria

Malaria remains a significant risk in many areas of the world, with resistance to the current antimalarial pharmacopeia an everincreasing problem. The M1 alanine aminopeptidase (PfM1AAP) and M17 leucine aminopeptidase (PfM17LAP) are believed to play a role in the terminal stages of digestion of host hemoglobin and thereby generate a pool of free amino acids that are essential for parasite growth and development. Here, we show that an orally bioavailable aminopeptidase inhibitor, CHR-2863, is efficacious against murine malaria

Validation of Agent-Based Models in Economics and Finance

Since the survey by Windrum et al. (Journal of Artificial Societies and Social Simulation 10:8, 2007), research on empirical validation of agent-based models in economics has made substantial advances, thanks to a constant flow of high-quality contributions. This Chapter attempts to take stock of such recent literature to offer an updated critical review of the existing validation techniques. We sketch a simple theoretical framework that conceptualizes existing validation approaches, which we examine along three different dimensions: (i) comparison between artificial and real-world data; (ii) calibration and estimation of model parameters; and (iii) parameter space exploration. Finally, we discuss open issues in the field of ABM validation and estimation. In particular, we argue that more research efforts should be devoted toward advancing hypothesis testing in ABM, with specific emphasis on model stationarity and ergodicity

Effect of early Vasopressin vs Norepinephrine on kidney failure in patients with septic shock : the VANISH randomized clinical trial

Importance Norepinephrine is currently recommended as the first-line vasopressor in septic shock; however, early vasopressin use has been proposed as an alternative. Objective To compare the effect of early vasopressin vs norepinephrine on kidney failure in patients with septic shock. Design, Setting, and Participants A factorial (2×2), double-blind, randomized clinical trial conducted in 18 general adult intensive care units in the United Kingdom between February 2013 and May 2015, enrolling adult patients who had septic shock requiring vasopressors despite fluid resuscitation within a maximum of 6 hours after the onset of shock. Interventions Patients were randomly allocated to vasopressin (titrated up to 0.06 U/min) and hydrocortisone (n = 101), vasopressin and placebo (n = 104), norepinephrine and hydrocortisone (n = 101), or norepinephrine and placebo (n = 103). Main Outcomes and Measures The primary outcome was kidney failure–free days during the 28-day period after randomization, measured as (1) the proportion of patients who never developed kidney failure and (2) median number of days alive and free of kidney failure for patients who did not survive, who experienced kidney failure, or both. Rates of renal replacement therapy, mortality, and serious adverse events were secondary outcomes. Results A total of 409 patients (median age, 66 years; men, 58.2%) were included in the study, with a median time to study drug administration of 3.5 hours after diagnosis of shock. The number of survivors who never developed kidney failure was 94 of 165 patients (57.0%) in the vasopressin group and 93 of 157 patients (59.2%) in the norepinephrine group (difference, −2.3% [95% CI, −13.0% to 8.5%]). The median number of kidney failure–free days for patients who did not survive, who experienced kidney failure, or both was 9 days (interquartile range [IQR], 1 to –24) in the vasopressin group and 13 days (IQR, 1 to –25) in the norepinephrine group (difference, −4 days [95% CI, −11 to 5]). There was less use of renal replacement therapy in the vasopressin group than in the norepinephrine group (25.4% for vasopressin vs 35.3% for norepinephrine; difference, −9.9% [95% CI, −19.3% to −0.6%]). There was no significant difference in mortality rates between groups. In total, 22 of 205 patients (10.7%) had a serious adverse event in the vasopressin group vs 17 of 204 patients (8.3%) in the norepinephrine group (difference, 2.5% [95% CI, −3.3% to 8.2%]). Conclusions and Relevance Among adults with septic shock, the early use of vasopressin compared with norepinephrine did not improve the number of kidney failure–free days. Although these findings do not support the use of vasopressin to replace norepinephrine as initial treatment in this situation, the confidence interval included a potential clinically important benefit for vasopressin, and larger trials may be warranted to assess this further

Factors influencing in-hospital mortality for salvage percutaneous transjugular intrahepatic portosystemic shunting in cirrhotic patients with recalcitrant variceal bleeding after failed endoscopic intervention

Background. Endoscopic therapy is the first-line treatment of choice for control of acute variceal bleeding (AVB). In high-risk patients with persistent AVB despite pharmacological treatment and endoscopic intervention, percutaneous transjugular intrahepatic portosystemic shunting (TIPS) provides a minimally invasive salvage method to reduce portal pressure and control bleeding. Objectives. To evaluate factors influencing in-hospital mortality after salvage TIPS (sTIPS) in patients with exsanguinating variceal bleeding despite medical treatment and endoscopic intervention. Methods. Clinical and laboratory data were analysed in all patients treated with sTIPS following failed endoscopic therapy for AVB between August 1991 and November 2020. Factors associated with and predictors of death were determined using bivariate analysis and univariate logistic regression analysis. Results. Thirty-four patients (29 men, 5 women), mean age 52 years (range 31 - 80), received sTIPS for uncontrolled (n=11) or refractory (n=23) AVB. The causes of portal hypertension were alcohol-related (n=24) and non-alcohol-related cirrhosis. Salvage TIPS controlled bleeding in 32 patients, with recurrence in 1. Ten patients died in hospital (mean 4.8 days, range 1 - 10) of liver failure (n=4), multiorgan failure (n=3), alcoholic cardiomyopathy (n=2) and uncontrolled gastric variceal bleeding (n=1). On bivariate analysis, factors associated with death were Child-Pugh (C-P) score ≥10 (p=0.006), sodium Model for End-stage Liver Disease (MELD-Na) score ≥22 (p<0.001), ≥8 units of blood transfused (p<0.001), Sengstaken-Blakemore balloon tube placement (p<0.001), endotracheal intubation (p<0.001), inotropic support (p<0.001) and endoscopically uncontrolled bleeding (p<0.001). Univariate logistic regression analysis showed that the most significant predictors of mortality were inotrope dependency (odds ratio (OR) 134; p<0.001), endotracheal intubation (OR 99; p<0.001), endoscopically uncontrolled bleeding (OR 28; p=0.001), grade 3 ascites (OR 20.9; p=0.012) and C-P grade C (OR 8.8; p=0.011). Conclusion. Salvage TIPS controlled variceal bleeding in 94% of patients after failed endoscopic therapy with 29% in-hospital mortality. The most significant predictors of mortality were C-P grade C, grade 3 ascites, inotrope requirement, endotracheal intubation and endoscopically uncontrolled bleeding