A Rawlsian algorithm for autonomous vehicles

Autonomous vehicles must be programmed with procedures for dealing with trolley-style dilemmas where actions result in harm to either pedestrians or passengers. This paper outlines a Rawlsian algorithm as an alternative to the Utilitarian solution. The algorithm will gather the vehicle’s estimation of probability of survival for each person in each action, then calculate which action a self-interested person would agree to if he or she were in an original bargaining position of fairness. I will employ Rawls’ assumption that the Maximin procedure is what self-interested agents would use from an original position, and then show how the Maximin procedure can be operationalized to produce unique outputs over probabilities of survival.     

Turning Crisis into Opportunity: Nature of Science and Scientific Inquiry as Illustrated in the Scientific Research on Severe Acute Respiratory Syndrome

Interviews with key scientists who had conducted research on Severe Acute Respiratory Syndrome (SARS), together with analysis of media reports, documentaries and other literature published during and after the SARS epidemic, revealed many interesting aspects of the nature of science (NOS) and scientific inquiry in contemporary scientific research in the rapidly growing field of molecular biology. The story of SARS illustrates vividly some NOS features advocated in the school science curriculum, including the tentative nature of scientific knowledge, theory-laden observation and interpretation, multiplicity of approaches adopted in scientific inquiry, the inter-relationship between science and technology, and the nexus of science, politics, social and cultural practices. The story also provided some insights into a number of NOS features less emphasised in the school curriculum—for example, the need to combine and coordinate expertise in a number of scientific fields, the intense competition between research groups (suspended during the SARS crisis), the significance of affective issues relating to intellectual honesty and the courage to challenge authority, the pressure of funding issues on the conduct of research and the ‘peace of mind’ of researchers, These less emphasised elements provided empirical evidence that NOS knowledge, like scientific knowledge itself, changes over time. They reflected the need for teachers and curriculum planners to revisit and reconsider whether the features of NOS currently included in the school science curriculum are fully reflective of the practice of science in the 21st century. In this paper, we also report on how we made use of extracts from the news reports and documentaries on SARS, together with episodes from the scientists’ interviews, to develop a multimedia instructional package for explicitly teaching the prominent features of NOS and scientific inquiry identified in the SARS research.

为何有超级病菌？

这是一场发生在人类与疾病之间的较量.如今的对手比以往任何时候都要顽强,人类还能取得胜利吗?     

Use of biochemical parameters for non-invasive screening of oesophageal varices in comparison to elastography-based approach in patients with compensated advanced chronic liver disease

IntroductionOesophageal varices are routinely diagnosed by esophagogastroduodenoscopy (EGD), and their bleeding has high mortality. We aimed to evaluate diagnostic performance of biochemical tests in comparison to elastography-based approaches, as non-invasive alternatives to EGD, for ruling-out high risk oesophageal varices (HRV).Material and methodsRetrospective analysis of patients (N = 861) who underwent liver stiffness measurement (LSM) by transient elastography (TE) in a single centre over 5-year period, with available results of EGD (within 3 months from LSM). Only patients with suspicion of compensated advanced chronic liver disease (cACLD) defined by LSM ≥ 10 kPa were included comprising the final cohort of 73 subjects. Original and expanded Baveno VI criteria (B6C), controlled attenuation parameter (CAP), platelet count (PLT), aspartate aminotransferase to PLT ratio index (APRI), Fibrosis-4 index (FIB4), model for end stage liver disease (MELD) score were evaluated against the results of EGD that served as the reference method.ResultsAnalysed patients had median age 62 years, 59/73 (0.81) were males, 54/73 (0.74) had alcoholic/non-alcoholic fatty liver disease, and 21/73 (0.29) had HRV. In multivariate logistic regression analysis only LSM and PLT were independently associated with HRV. The best performing tests for ruling-out HRV (% of spared EGD; % of missed HRV) were respectively: LSM < 20 kPa (53.4%; 0%), B6C (38%; 0%), Expanded B6C (47.9%; 4.8%); PLT > 214x10⁹/L (21.9%; 0%); FIB4 ≤ 1.8 (21.4%; 0%), APRI ≤ 0.34 (12.3%; 0%). CAP, MELD = 6 alone or combined with PLT > 150(x10⁹/L) did not show acceptable performance.ConclusionThe best performing biochemical tests for ruling-out HRV in our cohort of patients were PLT and FIB-4, but they were still outperformed by elastography-based approaches.Keyword: portal hypertension, cirrhosis, platelet count, esophageal varices, non-invasive tests     

A fluid collection system for dermal wounds in clinical investigations

In this work, we demonstrate the use of a thin, self adherent, and clinically durable patch device that can collect fluid from a wound site for analysis. This device is manufactured from laminated silicone layers using a novel all-silicone double-molding process. In vitro studies for flow and delivery were followed by a clinical demonstration for exudate collection efficiency from a clinically presented partial thickness burn. The demonstrated utility of this device lends itself for use as a research implement used to clinically sample wound exudate for analysis. This device can serve as a platform for future integration of wearable technology into wound monitoring and care. The demonstrated fabrication method can be used for devices requiring thin membrane construction.     

Measuring the degree of implementation of school-based assessment schemes for practical science

The study described in this paper investigated the degree of implementation of school-based assessment schemes for practical science. An assessment scheme in Hong Kong was used as the context for the research. Five dimensions of implementation were identified and a conceptual framework was built by breaking down each dimension into attributes and these into content areas. The research method used in the study incorporated some modifications on most past designs in order to determine adequately the construct validity of data and to examine any method-specific biases. Three measuring instruments (namely, a student questionnaire, a teacher questionnaire and an observation schedule) were designed. The construct validity of student data was demonstrated through confirmatory factor analysis and multitrait-multimethod analysis. Comparative analyses of students' perceptions, teacher self-reports and independent observational data resulted in convergent findings for only three out of the ten attributes of implementation.