Ramanujan sums as supercharacters

The theory of supercharacters, recently developed by Diaconis-Isaacs and Andre, can be used to derive the fundamental algebraic properties of Ramanujan sums. This machinery frequently yields one-line proofs of difficult identities and provides many novel formulas. In addition to exhibiting a new application of supercharacter theory, this article also serves as a blueprint for future work since some of the abstract results we develop are applicable in much greater generality.Comment: 32 pages. Comments welcom

Status and habitat requirements of Physaria thamnophila, an endangered species of Tamaulipan thornscrub

	Physaria (Lesquerella) thamnophila (Brassicaceae; henceforth Physaria) is an endangered herbaceous perennial plant of remnant patches of Tamaulipan thornscrub near the southern Texas border. Six years of censuses of four populations of Physaria were analyzed. Quantitative data were collected to describe the plant community in the four sites. There was no overall trend in population size, but fluctuations in observed numbers of plants among years were extremely large: a single census cannot provide a reliable assessment of a population of this species. Seedling numbers were positively related with shrub canopy cover. However, there were many more Physaria plants in the brush-cleared portion of one site than in its uncleared portion. Seedling survival may be facilitated by anything that reduces movement of the highly erodible soils of these sites

Dynamic deployment of web services on the internet or grid

PhD ThesisThis thesis focuses on the area of dynamic Web Service deployment for grid and Internet applications. It presents a new Dynamic Service Oriented Architecture (DynaSOAr) that enables the deployment of Web Services at run-time in response to consumer requests. The service-oriented approach to grid and Internet computing is centred on two parties: the service provider and the service consumer. This thesis investigates the introduction of mobility into this service-oriented approach allowing for better use of resources and improved quality of service. To this end, it examines the role of the service provider and makes the case for a clear separation of its concerns into two distinct roles: that of a Web Service Provider, whose responsibility is to receive and direct consumer requests and supply service implementations, and a Host Provider, whose role is to deploy services and process consumers' requests on available resources. This separation of concerns breaks the implicit bond between a published Web Service endpoint (network address) and the resource upon which the service is deployed. It also allows the architecture to respond dynamically to changes in service demand and the quality of service requirements. Clearly defined interfaces for each role are presented, which form the infrastructure of DynaSOAr. The approach taken is wholly based on Web Services. The dynamic deployment of service code between separate roles, potentially running in different administrative domains, raises a number of security issues which are addressed. A DynaSOAr service invocation involves three parties: the requesting Consumer, a Web Service Provider and a Host Provider; this tripartite relationship requires a security model that allows the concerns of each party to be enforced for a given invocation. This thesis, therefore, presents a Tripartite Security Model and an architecture that allows the representation, propagation and enforcement of three separate sets of constraints. A prototype implementation of DynaSOAr is used to evaluate the claims made, and the results show that a significant benefit in terms of round-trip execution time for data-intensive applications is achieved. Additional benefits in terms of parallel deployments to satisfy multiple concurrent requests are also shown

What influences chronic pain management? A best–worst scaling experiment with final year medical students and general practitioners

Background: Chronic pain education is an essential determinant for optimal chronic pain management. Given that attitudes and preferences are involved in making treatment decisions, identifying which factors are most influential to final year medical students’ and general practitioners’ (GPs) chronic pain management choices is of importance. This study investigates Swedish and Australian students’ preferences with respect to a chronic pain condition, using a best–worst scaling (BWS) experiment, which is designed to rank alternatives. Methods: BWS, a stated-preference method grounded in random utility theory, was used to explore the importance of factors influencing chronic pain management. Results: All three cohorts considered the patients’ pain description and previous treatment experience as the most important factors in making treatment decisions, whereas their demographics and voices or facial expressions while describing their pain were considered least important. Factors such as social support, patient preferences and treatment adherence were, however, disregarded by all cohorts in favour of pain assessment factors such as pain ratings, description and history. Swedish medical students and GPs show very high correlation in their choices, although the GPs consider their professional experience as more important compared to the students. Conclusion: This study suggests that the relative importance of treatment factors is cemented early and thus underline the critical importance of improving pain curricula during undergraduate medical education

Differences in Swedish and Australian medical student attitudes and beliefs about chronic pain, its management, and the way it is taught

Background and aims: Medical students receive training in the management of chronic pain, but the training is often suboptimal. Considering that the basis for physician’s knowledge is their medical education, it is important to explore the attitudes and beliefs of medical students with respect both to chronic pain management and to their views on current pain education. Therefore, the aim of this study was to compare Swedish and Australian medical student’s attitudes and beliefs about patients with chronic pain, and their perceptions regarding their chronic pain management education. Methods: An online survey was conducted with final year Australian and Swedish medical students from two different universities between December 2016 and February 2017. Attitudes and beliefs towards chronic pain patients were measured using the Health Care Providers’ Pain and Impairment Scale (HC-PAIRS). A thematic analysis was conducted on open end questions regarding their views on their education and important skills for chronic pain management. Results: A total of 57 Swedish and 26 Australian medical students completed the HC-PAIRS scale. The Swedish medical students showed statistically significantly lower total mean HC-PAIRS scores compared to Australian medical students (46 and 51, respectively). Australian students had statistically significantly higher scores than the Swedish students for two of four factors: functional expectations and need for cure, whereas no significant differences were seen for the factors social expectations or for projected cognition. From the open end questions it was evident that final year medical students are knowledgeable about key chronic pain items described in clinical guidelines. However, both cohorts described their chronic pain training as poor and in need of improvement in several areas such as more focus on the biopsychosocial model, working in multidisciplinary teams, seeing chronic pain patients and pharmacological training. Conclusions: Attitudes and beliefs are formed during medical education, and our study exploring attitudes of medical students towards chronic pain and how it is taught have provided valuable information. Our survey provided detailed and cohesive suggestions for education improvement that also are in line with current clinical guidelines. This study indicates that the Swedish final year students have a more positive attitude towards chronic pain patients compared to their Australian counterparts. The majority of students in both cohorts perceived chronic pain management education in need of improvement. Implications: This study highlights several areas of interest that warrant further investigation, for example, the impact of a changed medical curriculum in alignment with these clinical guidelines requested by students in this survey, and correspondingly if their attitudes towards chronic pain patients can be improved through education. Further, we conclude that it would be valuable to align the implementation of the HC-PAIRS instrument in order to achieve comparable results between future studies