Showing papers by "Brunel University London published in 2016"

Event generator tunes obtained from underlying event and multiparton scattering measurements

Abstract: New sets of parameters ("tunes") for the underlying-event (UE) modeling of the PYTHIA8, PYTHIA6 and HERWIG++ Monte Carlo event generators are constructed using different parton distribution functions. Combined fits to CMS UE data at sqrt(s) = 7 TeV and to UE data from the CDF experiment at lower sqrt(s), are used to study the UE models and constrain their parameters, providing thereby improved predictions for proton-proton collisions at 13 TeV. In addition, it is investigated whether the values of the parameters obtained from fits to UE observables are consistent with the values determined from fitting observables sensitive to double-parton scattering processes. Finally, comparisons of the UE tunes to "minimum bias" (MB) events, multijet, and Drell-Yan (q q-bar to Z / gamma* to lepton-antilepton + jets) observables at 7 and 8 TeV are presented, as well as predictions of MB and UE observables at 13 TeV.

Exploring the factors affecting MOOC retention

Abstract: Massive Open Online Courses (MOOCs) hold the potential to open up educational opportunities to a global audience. However, evidence suggests that only a small proportion of MOOC participants go on to complete their courses and relatively little is understood about the MOOC design and implementation factors that influence retention. This paper reports a survey study of 379 participants enrolled at university in Cairo who were encouraged to take a MOOC of their own choice as part of their development. 122 participants (32.2%) went onto to complete an entire course. There were no significant differences in completion rates by gender, level of study (undergraduate or postgraduate) or MOOC platform. A post-MOOC survey of students' perceptions found that MOOC Course Content was a significant predictor of MOOC retention, with the relationship mediated by the effect of content on the Perceived Effectiveness of the course. Interaction with the instructor of the MOOC was also found to be significant predictor of MOOC retention. Overall these constructs explained 79% of the variance in MOOC retention. We present a model explaining 79% of variance in MOOC learner retention.Course content affects MOOC learner retention via Perceived Effectiveness.Interaction with instructor affects MOOC learner retention directly.Those who pass the mid-point of a MOOC are likely to complete.

Evolutionary Multi-Objective Workflow Scheduling in Cloud

Abstract: Cloud computing provides promising platforms for executing large applications with enormous computational resources to offer on demand. In a Cloud model, users are charged based on their usage of resources and the required quality of service (QoS) specifications. Although there are many existing workflow scheduling algorithms in traditional distributed or heterogeneous computing environments, they have difficulties in being directly applied to the Cloud environments since Cloud differs from traditional heterogeneous environments by its service-based resource managing method and pay-per-use pricing strategies. In this paper, we highlight such difficulties, and model the workflow scheduling problem which optimizes both makespan and cost as a Multi-objective Optimization Problem (MOP) for the Cloud environments. We propose an evolutionary multi-objective optimization (EMO)-based algorithm to solve this workflow scheduling problem on an infrastructure as a service (IaaS) platform. Novel schemes for problem-specific encoding and population initialization, fitness evaluation and genetic operators are proposed in this algorithm. Extensive experiments on real world workflows and randomly generated workflows show that the schedules produced by our evolutionary algorithm present more stability on most of the workflows with the instance-based IaaS computing and pricing models. The results also show that our algorithm can achieve significantly better solutions than existing state-of-the-art QoS optimization scheduling algorithms in most cases. The conducted experiments are based on the on-demand instance types of Amazon EC2; however, the proposed algorithm are easy to be extended to the resources and pricing models of other IaaS services.

An open letter to The BMJ editors on qualitative research

Abstract: Seventy six senior academics from 11 countries invite The BMJ ’s editors to reconsider their policy of rejecting qualitative research on the grounds of low priority. They challenge the journal to develop a proactive, scholarly, and pluralist approach to research that aligns with its stated mission

Interface and bonding mechanisms of plant fibre composites: An overview

Abstract: The development of plant fibre composite is on the rise for a wide range of applications. Probably a single most important aspect with respect to the formulation of plant fibre composites with superior mechanical performance is the optimization of the interfacial bonding between the reinforcing plant fibre and polymer matrix. While the interface plays a pivotal role in determining the mechanical properties, e.g. transferring the stress and distributing the bond, it is among the least understood components of the composite. This paper presents an overview of the compatibility between the heterogeneous constituents of plant fibre composite, various modification approaches aiming at overcoming the incompatibility and refining the interfacial adhesion of the composite, interfacial bonding mechanisms, and the assessment of interface structure and bonding. It has been found that 1) the physical and chemical incompatibility between the fibre and matrix, leading to poor dispersion, weak interfacial adhesion and ultimately inferior composite quality, could be overcome through strategical modifications; 2) inter-diffusion, electrostatic adhesion, chemical reactions and mechanical interlocking are in general responsible for the interfacial bonding and adhesion of plant fibre composites; and 3) a thorough knowledge of structure-property relationship of the composite could be established by conducting a set of direct and indirect interfacial assessments. This paper finishes with some critical suggestions and future perspectives, underscoring the roles of composite material researchers and engineers for the further in-depth studies and up-scale commercialization of plant fibre composite.

Extending the utaut model to understand the customers' acceptance and use of internet banking in lebanon a structural equation modeling approach

Abstract: Purpose A number of studies have shown that internet banking (IB) implementation is not only determined by banks or government support, but also by perceptions and experience of IB users. IB studies have showed encouraging results from academics in developed countries. Yet little is known about the user adoption of IB in Lebanon. The purpose of this paper is to investigate the factors that may hinder or facilitate the acceptance and usage of IB in Lebanon. Design/methodology/approach A conceptual framework was developed through extending the unified theory of acceptance and use of technology (UTAUT) by incorporating two additional factors namely; perceived credibility (PC) and task-technology fit (TTF). A quantitative approach based on cross-sectional survey was used to collect data from 408 IB consumers. Data were analysed using structural equation modelling based on AMOS 20.0. Findings The results of the structural path revealed that performance expectancy (PE), social influence, PC and TTF to be significant predictors in influencing customers’ behavioural intention (BI) to use IB and explained 61 per cent of its variance, with PE was found the strongest antecedent of BI. Contrary to the UTAUT, the effect of effort expectancy on BI was insignificant. In addition, both BI and facilitating conditions were found to affect the actual usage behaviour and explained 64 per cent of its variance Practical implications This study would be helpful for bank managers and policy makers to explain the currently relatively low penetration rate of IB in formulating strategies to encourage the adoption and acceptance of IB by Lebanese customers, where IB is still considered an innovation. Originality/value This study is the first research that extend the UTAUT by incorporating two additional factors namely; PC and TTF to study the IB in the Lebanese context. This study contributes to the research on computer technology usage by looking at IB adoption and incorporation into the lives of customers via the BI to use and actual usage of IB in Lebanon.

The Ontology for Biomedical Investigations

Abstract: The Ontology for Biomedical Investigations (OBI) is an ontology that provides terms with precisely defined meanings to describe all aspects of how investigations in the biological and medical domains are conducted. OBI re-uses ontologies that provide a representation of biomedical knowledge from the Open Biological and Biomedical Ontologies (OBO) project and adds the ability to describe how this knowledge was derived. We here describe the state of OBI and several applications that are using it, such as adding semantic expressivity to existing databases, building data entry forms, and enabling interoperability between knowledge resources. OBI covers all phases of the investigation process, such as planning, execution and reporting. It represents information and material entities that participate in these processes, as well as roles and functions. Prior to OBI, it was not possible to use a single internally consistent resource that could be applied to multiple types of experiments for these applications. OBI has made this possible by creating terms for entities involved in biological and medical investigations and by importing parts of other biomedical ontologies such as GO, Chemical Entities of Biological Interest (ChEBI) and Phenotype Attribute and Trait Ontology (PATO) without altering their meaning. OBI is being used in a wide range of projects covering genomics, multi-omics, immunology, and catalogs of services. OBI has also spawned other ontologies (Information Artifact Ontology) and methods for importing parts of ontologies (Minimum information to reference an external ontology term (MIREOT)). The OBI project is an open cross-disciplinary collaborative effort, encompassing multiple research communities from around the globe. To date, OBI has created 2366 classes and 40 relations along with textual and formal definitions. The OBI Consortium maintains a web resource (http://obi-ontology.org) providing details on the people, policies, and issues being addressed in association with OBI. The current release of OBI is available at http://purl.obolibrary.org/obo/obi.owl.

A Jordanian empirical study of the associations among transformational leadership, transactional leadership, knowledge sharing, job performance, and firm performance: A structural equation modelling approach

Abstract: Purpose – Knowledge sharing adoption has been considered as a significant practice for organizations. However, there is a modest empirical confirmation to indicate how these organizations value the richness of their knowledge capabilities. The purpose of this paper is to investigate both transformational and transactional leadership styles that influence employees’ knowledge sharing practices, and the impact of the latter on job performance, and then on firm performance. Design/methodology/approach – Data collected from 179 employees at the higher council of youth in Jordan were empirically tested using structural equation modelling. Findings – The findings revealed that both transformational and transactional leadership styles have significant impact on job performance, and the latter on firm performance. Also, it was found that transactional leadership impacted knowledge sharing, whereas transformational leadership did not. Originality/value – This research proposes a new approach to understand knowledg...

A meta-review of stress, coping and interventions in dementia and dementia caregiving

Abstract: There has been a substantial number of systematic reviews of stress, coping and interventions for people with dementia and their caregivers. This paper provides a meta-review of this literature 1988-2014. A meta-review was carried out of systematic reviews of stress, coping and interventions for people with dementia and their caregivers, using SCOPUS, Google Scholar and CINAHL Plus databases and manual searches. The meta-review identified 45 systematic reviews, of which 15 were meta-analyses. Thirty one reviews addressed the effects of interventions and 14 addressed the results of correlational studies of factors associated with stress and coping. Of the 31 systematic reviews dealing with intervention studies, 22 focused on caregivers, 6 focused on people with dementia and 3 addressed both groups. Overall, benefits in terms of psychological measures of mental health and depression were generally found for the use of problem focused coping strategies and acceptance and social-emotional support coping strategies. Poor outcomes were associated with wishful thinking, denial, and avoidance coping strategies. The interventions addressed in the systematic reviews were extremely varied and encompassed Psychosocial, Psychoeducational, Technical, Therapy, Support Groups and Multicomponent interventions. Specific outcome measures used in the primary sources covered by the systematic reviews were also extremely varied but could be grouped into three dimensions, viz., a broad dimension of “Psychological Well-Being v. Psychological Morbidity” and two narrower dimensions of “Knowledge and Coping” and of “Institutionalisation Delay”. This meta-review supports the conclusion that being a caregiver for people with dementia is associated with psychological stress and physical ill-health. Benefits in terms of mental health and depression were generally found for caregiver coping strategies involving problem focus, acceptance and social-emotional support. Negative outcomes for caregivers were associated with wishful thinking, denial and avoidance coping strategies. Psychosocial and Psychoeducational interventions were beneficial for caregivers and for people with dementia. Support groups, Multicomponent interventions and Joint Engagements by both caregivers and people with dementia were generally found to be beneficial. It was notable that virtually all reviews addressed very general coping strategies for stress broadly considered, rather than in terms of specific remedies for specific sources of stress. Investigation of specific stressors and remedies would seem to be a useful area for future research.

Trans-ancestry meta-analyses identify rare and common variants associated with blood pressure and hypertension

Abstract: High blood pressure is a major risk factor for cardiovascular disease and premature death. However, there is limited knowledge on specific causal genes and pathways. To better understand the genetics of blood pressure, we genotyped 242,296 rare, low-frequency and common genetic variants in up to 192,763 individuals and used -1/4155,063 samples for independent replication. We identified 30 new blood pressure- or hypertension-associated genetic regions in the general population, including 3 rare missense variants in RBM47, COL21A1 and RRAS with larger effects (>1.5 mm Hg/allele) than common variants. Multiple rare nonsense and missense variant associations were found in A2ML1, and a low-frequency nonsense variant in ENPEP was identified. Our data extend the spectrum of allelic variation underlying blood pressure traits and hypertension, provide new insights into the pathophysiology of hypertension and indicate new targets for clinical intervention.

International Olympic Committee consensus statement: harassment and abuse (non-accidental violence) in sport.

Abstract: Despite the well-recognised benefits of sport, there are also negative influences on athlete health, well-being and integrity caused by non-accidental violence through harassment and abuse. All athletes have a right to engage in 'safe sport', defined as an athletic environment that is respectful, equitable and free from all forms of non-accidental violence to athletes. Yet, these issues represent a blind spot for many sport organisations through fear of reputational damage, ignorance, silence or collusion. This consensus statement extends the 2007 IOC Consensus Statement on Sexual Harassment and Abuse in Sport, presenting additional evidence of several other types of harassment and abuse-psychological, physical and neglect. All ages and types of athletes are susceptible to these problems but science confirms that elite, disabled, child and lesbian/gay/bisexual/trans-sexual (LGBT) athletes are at highest risk, that psychological abuse is at the core of all other forms and that athletes can also be perpetrators. Harassment and abuse arise from prejudices expressed through power differences. Perpetrators use a range of interpersonal mechanisms including contact, non-contact/verbal, cyber-based, negligence, bullying and hazing. Attention is paid to the particular risks facing child athletes, athletes with a disability and LGBT athletes. Impacts on the individual athlete and the organisation are discussed. Sport stakeholders are encouraged to consider the wider social parameters of these issues, including cultures of secrecy and deference that too often facilitate abuse, rather than focusing simply on psychopathological causes. The promotion of safe sport is an urgent task and part of the broader international imperative for good governance in sport. A systematic multiagency approach to prevention is most effective, involving athletes, entourage members, sport managers, medical and therapeutic practitioners, educators and criminal justice agencies. Structural and cultural remedies, as well as practical recommendations, are suggested for sport organisations, athletes, sports medicine and allied disciplines, sport scientists and researchers. The successful prevention and eradication of abuse and harassment against athletes rests on the effectiveness of leadership by the major international and national sport organisations.

Government-subsidized R&D and Firm Innovation: Evidence from China

Abstract: This study investigates the effects of government R&D programs on firm innovation outputs, which are measured by the number of patents, sales from new products, and exports. Particularly, we examine the effects of Innovation Fund for Small and Medium Technology-based Firms (Innofund), which is one of the largest government R&D programs that support R&D activities of small and medium-sized enterprises in China. Using a panel dataset on Chinese manufacturing firms from 1998 to 2007, we find that Innofund-backed firms generate significantly higher technological and commercialized innovation outputs compared with their non-Innofund-backed counterparts and the same firms before winning the grant. Moreover, the changes in the governance of Innofund in 2005 from a centralized to a decentralized one because of policy amendments have significant effects on the effectiveness of the program. Specifically, the magnified effects of Innofund on technological innovation outputs become significantly stronger after the governance of Innofund becomes more decentralized. Identification problems are addressed by utilizing both propensity score matching and two-stage estimation approaches.

Pareto or Non-Pareto: Bi-Criterion Evolution in Multiobjective Optimization

Abstract: It is known that Pareto dominance has its own weaknesses as the selection criterion in evolutionary multiobjective optimization. Algorithms based on Pareto criterion (PC) can suffer from problems such as slow convergence to the optimal front and inferior performance on problems with many objectives. Non-Pareto criterion (NPC), such as decomposition-based criterion and indicator-based criterion, has already shown promising results in this regard, but its high selection pressure may lead to the algorithm to prefer some specific areas of the problem’s Pareto front, especially when the front is highly irregular. In this paper, we propose a bi-criterion evolution (BCE) framework of the PC and NPC, which attempts to make use of their strengths and compensates for each other’s weaknesses. The proposed framework consists of two parts: PC evolution and NPC evolution. The two parts work collaboratively, with an abundant exchange of information to facilitate each other’s evolution. Specifically, the NPC evolution leads the PC evolution forward and the PC evolution compensates the possible diversity loss of the NPC evolution. The proposed framework keeps the freedom on the implementation of the NPC evolution part, thus making it applicable for any non-Pareto-based algorithm. In the PC evolution, two operations, population maintenance and individual exploration, are presented. The former is to maintain a set of representative nondominated individuals and the latter is to explore some promising areas that are undeveloped (or not well-developed) in the NPC evolution. Experimental results have shown the effectiveness of the proposed framework. The BCE works well on seven groups of 42 test problems with various characteristics, including those in which Pareto-based algorithms or non-Pareto-based algorithms struggle.

Measuring Organizational Performance: A Case for Subjective Measures

Abstract: We review the organisational performance (OP) measurement literature highlighting the limitations of both objective and subjective measures of performance. We argue that, with careful planning, subjective measures can be successfully employed to assess OP. This is because often consistent, reliable and comparable compatible objective data on OP measures—particularly across countries and sectors—is difficult to come by. Considering that an inflated OP measure can be cross-checked with the use of secondary data, managers have little incentive to report such figures. As a result, when quizzed over the stand-alone performance measures of their organisations or vis-a-vis their rivals, managers accurately assess and respond to questions on the performance of their organisations. An in-depth statistical exercise conducted on the subjective measures of OP as reported by managers of four sets of companies in four separate countries, show consistent results, thus lending support to this premise.

Research impact: a narrative review.

Abstract: Impact occurs when research generates benefits (health, economic, cultural) in addition to building the academic knowledge base. Its mechanisms are complex and reflect the multiple ways in which knowledge is generated and utilised. Much progress has been made in measuring both the outcomes of research and the processes and activities through which these are achieved, though the measurement of impact is not without its critics. We review the strengths and limitations of six established approaches (Payback, Research Impact Framework, Canadian Academy of Health Sciences, monetisation, societal impact assessment, UK Research Excellence Framework) plus recently developed and largely untested ones (including metrics and electronic databases). We conclude that (1) different approaches to impact assessment are appropriate in different circumstances; (2) the most robust and sophisticated approaches are labour-intensive and not always feasible or affordable; (3) whilst most metrics tend to capture direct and proximate impacts, more indirect and diffuse elements of the research-impact link can and should be measured; and (4) research on research impact is a rapidly developing field with new methodologies on the horizon.

Cardiovascular adaptations supporting human exercise-heat acclimation

Abstract: This review examines the cardiovascular adaptations along with total body water and plasma volume adjustments that occur in parallel with improved heat loss responses during exercise-heat acclimation. The cardiovascular system is well recognized as an important contributor to exercise-heat acclimation that acts to minimize physiological strain, reduce the risk of serious heat illness and better sustain exercise capacity. The upright posture adopted by humans during most physical activities and the large skin surface area contribute to the circulatory and blood pressure regulation challenge of simultaneously supporting skeletal muscle blood flow and dissipating heat via increased skin blood flow and sweat secretion during exercise-heat stress. Although it was traditionally held that cardiac output increased during exercise-heat stress to primarily support elevated skin blood flow requirements, recent evidence suggests that temperature-sensitive mechanisms may also mediate an elevation in skeletal muscle blood flow. The cardiovascular adaptations supporting this challenge include an increase in total body water, plasma volume expansion, better sustainment and/or elevation of stroke volume, reduction in heart rate, improvement in ventricular filling and myocardial efficiency, and enhanced skin blood flow and sweating responses. The magnitude of these adaptations is variable and dependent on several factors such as exercise intensity, duration of exposure, frequency and total number of exposures, as well as the environmental conditions (i.e. dry or humid heat) in which acclimation occurs.

The EQ-5D-5L health status questionnaire in COPD: validity, responsiveness and minimum important difference

Abstract: Background The EQ-5D, a generic health status questionnaire that is widely used in health economic evaluation, was recently expanded to the EQ-5D-5L to address criticisms of unresponsiveness and ceiling effect. Aims To describe the validity, responsiveness and minimum important difference of the EQ-5D-5L in COPD. Methods Study 1: The validity of the EQ-5D-5L utility index and visual analogue scale (EQ-VAS) was compared with four established disease-specific health status questionnaires and other measures of disease severity in 616 stable outpatients with COPD. Study 2: The EQ-5D-5L utility index and EQ-VAS were measured in 324 patients with COPD before and after 8 weeks of pulmonary rehabilitation. Distribution and anchor-based approaches were used to estimate the minimum important difference. Results There were moderate-to-strong correlations between utility index and EQ-VAS with disease-specific questionnaires (Pearson9s r=0.47–0.72). A ceiling effect was seen in 7% and 2.6% of utility index and EQ-VAS. Utility index decreased (worsening health status) with indices of worsening disease severity. With rehabilitation, mean (95% CI) changes in utility index and EQ-VAS were 0.065 (0.047 to 0.083) and 8.6 (6.5 to 10.7), respectively, with standardised response means of 0.39 and 0.44. The mean (range) anchor estimates of the minimum important difference for utility index and EQ-VAS were 0.051 (0.037 to 0.063) and 6.9 (6.5 to 8.0), respectively. Conclusions The EQ-5D-5L is a valid and responsive measure of health status in COPD and may provide useful additional cost-effectiveness data in clinical trials.

An Event-Triggered Approach to State Estimation for a Class of Complex Networks With Mixed Time Delays and Nonlinearities

Abstract: In this paper, the state estimation problem is investigated for a class of discrete-time complex networks subject to nonlinearities, mixed delays, and stochastic noises. A set of event-based state estimators is constructed so as to reduce unnecessary data transmissions in the communication channel. Compared with the traditional state estimator whose measurement signal is received under a periodic clock-driven rule, the event-based estimator only updates the measurement information from the sensors when the prespecified “event” is violated. Attention is focused on the analysis and design problem of the event-based estimators for the addressed discrete-time complex networks such that the estimation error is exponentially bounded in mean square. A combination of the stochastic analysis approach and Lyapunov theory is employed to obtain sufficient conditions for ensuring the existence of the desired estimators and the upper bound of the estimation error is also derived. By using the convex optimization technique, the gain parameters of the desired estimators are provided in an explicit form. Finally, a simulation example is used to demonstrate the effectiveness of the proposed estimation strategy.

Local anaesthetic sympathetic blockade for complex regional pain syndrome

Abstract: Background This review is an update of a previously published review in the Cochrane Database of Systematic Reviews, 2005, Issue 4 (and last updated in the Cochrane Database of Systematic Reviews, 2013 issue 8), on local anaesthetic blockade (LASB) of the sympathetic chain to treat people with complex regional pain syndrome (CRPS). Objectives To assess the efficacy of LASB for the treatment of pain in CRPS and to evaluate the incidence of adverse effects of the procedure. Search methods For this update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 9), MEDLINE (Ovid), EMBASE (Ovid), LILACS (Birme), conference abstracts of the World Congresses of the International Association for the Study of Pain, and various clinical trial registers up to September 2015. We also searched bibliographies from retrieved articles for additional studies. Selection criteria We considered randomised controlled trials (RCTs) that evaluated the effect of sympathetic blockade with local anaesthetics in children or adults with CRPS compared to placebo, no treatment, or alternative treatments. Data collection and analysis We used standard methodological procedures expected by Cochrane. The outcomes of interest were reduction in pain intensity, the proportion who achieved moderate or substantial pain relief, the duration of pain relief, and the presence of adverse effects in each treatment arm. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created a 'Summary of findings' table. Main results We included an additional four studies (N = 154) in this update. For this update, we excluded studies that did not follow up patients for more than 48 hours. As a result, we excluded four studies from the previous review in this update. Overall we included 12 studies (N = 461), all of which we judged to be at high or unclear risk of bias. Overall, the quality of evidence was low to very low, downgraded due to limitations, inconsistency, imprecision, indirectness, or a combination of these. Two small studies compared LASB to placebo/sham (N = 32). They did not demonstrate significant short-term benefit for LASB for pain intensity (moderate quality evidence). One small study (N = 36) at high risk of bias compared thoracic sympathetic block with corticosteroid and local anaesthetic versus injection of the same agents into the subcutaneous space, reporting statistically significant and clinically important differences in pain intensity at one-year follow-up but not at short term follow-up (very low quality evidence). Of two studies that investigated LASB as an addition to rehabilitation treatment, the only study that reported pain outcomes demonstrated no additional benefit from LASB (very low quality evidence). Eight small randomised studies compared sympathetic blockade to various other active interventions. Most studies found no difference in pain outcomes between sympathetic block versus other active treatments (low to very low quality evidence). One small study compared ultrasound-guided LASB with non-guided LASB and found no clinically important difference in pain outcomes (very low quality evidence). Six studies reported adverse events, all with minor effects reported. Authors' conclusions This update's results are similar to the previous versions of this systematic review, and the main conclusions are unchanged. There remains a scarcity of published evidence and a lack of high quality evidence to support or refute the use of local anaesthetic sympathetic blockade for CRPS. From the existing evidence, it is not possible to draw firm conclusions regarding the efficacy or safety of this intervention, but the limited data available do not suggest that LASB is effective for reducing pain in CRPS.