Evaluation of quality attributes in the freight transport market. Stated preference experiments in Switzerland

Globalization and European integration increase the claim for better quality in freight transport and logistics services. The paper focuses on the evaluation of different quality attributes of transport services in a significant segment in the Swiss freight market. The paper is based on conjoint analysis, generated by discrete binary choices between alternatives of hypothetical transport services, described by a combination of four attributes articulated on different levels. The estimated results confirm the high importance of punctuality and avoidance of damages. It could also show the statistically significant relation of the declining value of time with increasing distance

Towards the 3D Web with Open Simulator

Continuing advances and reduced costs in computational power, graphics processors and network bandwidth have led to 3D immersive multi-user virtual worlds becoming increasingly accessible while offering an improved and engaging Quality of Experience. At the same time the functionality of the World Wide Web continues to expand alongside the computing infrastructure it runs on and pages can now routinely accommodate many forms of interactive multimedia components as standard features - streaming video for example. Inevitably there is an emerging expectation that the Web will expand further to incorporate immersive 3D environments. This is exciting because humans are well adapted to operating in 3D environments and it is challenging because existing software and skill sets are focused around competencies in 2D Web applications. Open Simulator (OpenSim) is a freely available open source tool-kit that empowers users to create and deploy their own 3D environments in the same way that anyone can create and deploy a Web site. Its characteristics can be seen as a set of references as to how the 3D Web could be instantiated. This paper describes experiments carried out with OpenSim to better understand network and system issues, and presents experience in using OpenSim to develop and deliver applications for education and cultural heritage. Evaluation is based upon observations of these applications in use and measurements of systems both in the lab and in the wild.Postprin

Fidelity perception of 3D models on the web

Cultural heritage artefacts act as a gateway helping people learn about their social traditions and history. However, preserving these artefacts faces many difficulties, including potential destruction or damage from global warming, wars and conflicts, and degradation from day-to-day use. In addition, artefacts can only be present in one place at a time, and many of them can not be exhibited due to the limited physical space of museums. The digital domain offers opportunities to capture and represent the form and texture of these artefacts and to overcome the previously mentioned constraints by allowing people to access and interact with them on multiple platforms (mobile devices, tablets and personal computers) and network regimes. Through two experiments we study the subjective perception of the fidelity of 3D models in web browsers in order to discover perceptible resolution thresholds. This helps us create models of reasonable graphical complexity that could be fetched on the biggest range of end devices. It also enables us to design systems which efficiently optimise the user experience by adapting their behaviour based upon user perception, model characteristics and digital infrastructure.Postprin

Immersive Installation: “A Virtual St Kilda”

This paper discusses a Virtual Histories project, which developed a digital reconstruction of St Kilda. St Kilda is the most remote and western part of the United Kingdom. It was evacuated in the 1930s and lay empty for several decades. It is a world heritage site for both built and natural environment . The Virtual St Kilda acted as a focus for the collection and presentation of tangible and intangible cultural heritage. It was on show as an exhibition in the Taigh Chearsabah museum (Figure 5) located in North Uist Scotland. The exhibition is built around the OpenSimulator Open VirtualWorld server using commodity hardware. The simulation covers some 4 square km of virtual space, and models both tangible and intangible culture. It is integrated into an exhibition and articulates an interpretation of the St Kilda legacy through the prism of contemporary North Uist life.Postprin

Growing the use of Virtual Worlds in education : an OpenSim perspective

The growth in the range of disciplines that Virtual Worlds support for educational purposes is evidenced by recent applications in the fields of cultural heritage, humanitarian aid, space exploration, virtual laboratories in the physical sciences, archaeology, computer science and coastal geography. This growth is due in part to the flexibility of OpenSim, the open source virtual world platform which by adopting Second Life protocols and norms has created a de facto standard for open virtual worlds that is supported by a growing number of third party open source viewers. Yet while this diversity of use-cases is impressive and Virtual Worlds for open learning are highly popular with lecturers and learners alike immersive education remains an essentially niche activity. This paper identifies functional challenges in terms of Management, Network Infrastructure, the Immersive 3D Web and Programmability that must be addressed to enable the wider adoption of Open Virtual Worlds as a routine learning technology platform. We refer to specific use-cases based on OpenSim and abstract generic requirements which should be met to enable the growth in use of Open Virtual Worlds as a mainstream educational facility. A case study of a deployment to support a formal education curriculum and associated informal learning is used to illustrate key points.Postprin

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Erratum to: Methods for evaluating medical tests and biomarkers

[This corrects the article DOI: 10.1186/s41512-016-0001-y.]

The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.

Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707