University of Exeter

About: University of Exeter is a education organization based out in Exeter, United Kingdom. It is known for research contribution in the topics: Population & Climate change. The organization has 15820 authors who have published 50650 publications receiving 1793046 citations. The organization is also known as: Exeter University & University of the South West of England.

Multiobjective Genetic Algorithms for Design of Water Distribution Networks

Abstract: This paper presents a multiobjective genetic algorithm approach to the design of a water distribution network. The objectives considered are minimization of the network cost and maximization of a reliability measure. In this study, a new reliability measure, called network resilience, is introduced. This measure mimics a designer's desire of providing excess head above the minimum allowable head at the nodes and of designing reliable loops with practicable pipe diameters. The proposed method produces a set of Pareto-optimal solutions in the search space of cost and network resilience. Genetic algorithms are observed to be poor in handling constraints. To handle constraints in a better way, a constraint handling technique that does not require a penalty coefficient and is applicable to water distribution systems is presented. The present model is applied to two example problems, which are widely reported. Comparison of the present method with other methods revealed that the network resilience based approach gave better results.

Surface plasmon–polariton length scales: a route to sub-wavelength optics

Abstract: We look at four length scales associated with the surface plasmon–polariton (SPP) modes in the visible and near-infrared. We examine some of the consequences of these length scales for exploiting surface plasmon–polariton modes as a means to provide sub-wavelength optics. The four length scales discussed are the SPP wavelength, the SPP propagation distance, and the penetration depths of the field associated with the SPP into the dielectric and metal media that bound the interface that supports the SPP. Length scales spanning seven orders of magnitude, from nanometres to centimetres, are of relevance to SPPs. This paper concludes by identifying some of the challenges that lie ahead.

Teaching anatomy without cadavers.

Abstract: Background Anatomy learning is generally seen as essential to medicine, and exposure to cadavers is generally seen as essential to anatomy learning around the world. Few voices dissenting from these propositions can be identified. Aims This paper aims to consider arguments relating to the use of cadavers in anatomy teaching, and to describe the rationale behind the decision of a new UK medical school not to use cadaveric material. Discussion First, the background to use of cadavers in anatomy learning is explored, and some general educational principles are explored. Next, arguments for the use of human cadaveric material are summarised. Then, possible arguments against use of cadavers, including educational principles as well as costs, hazards and practicality, are considered. These are much less well explored in the existing literature. Next, the rationale behind the decision of a new UK medical school not to use cadaveric material is indicated, and the programme of anatomy teaching to be employed in the absence of the use of human remains is described. Curriculum design and development, and evaluation procedures, are briefly described. Issues surrounding pathology training by autopsy, and postgraduate training in surgical anatomy, are not addressed in this paper. Future directions Evidence relating to the effect on medical learning by students not exposed to cadavers is scant, and plainly opportunities will now arise through our programme to gather such evidence. We anticipate that this discussion paper will contribute to an ongoing debate, in which virtually all previous papers on this topic have concluded that use of cadavers is essential to medical learning.

Experimentally induced innovations lead to persistent culture via conformity in wild birds

Abstract: In human societies, cultural norms arise when behaviours are transmitted through social networks via high-fidelity social learning. However, a paucity of experimental studies has meant that there is no comparable understanding of the process by which socially transmitted behaviours might spread and persist in animal populations. Here we show experimental evidence of the establishment of foraging traditions in a wild bird population. We introduced alternative novel foraging techniques into replicated wild sub-populations of great tits (Parus major) and used automated tracking to map the diffusion, establishment and long-term persistence of the seeded innovations. Furthermore, we used social network analysis to examine the social factors that influenced diffusion dynamics. From only two trained birds in each sub-population, the information spread rapidly through social network ties, to reach an average of 75% of individuals, with a total of 414 knowledgeable individuals performing 57,909 solutions over all replicates. The sub-populations were heavily biased towards using the technique that was originally introduced, resulting in established local traditions that were stable over two generations, despite a high population turnover. Finally, we demonstrate a strong effect of social conformity, with individuals disproportionately adopting the most frequent local variant when first acquiring an innovation, and continuing to favour social information over personal information. Cultural conformity is thought to be a key factor in the evolution of complex culture in humans. In providing the first experimental demonstration of conformity in a wild non-primate, and of cultural norms in foraging techniques in any wild animal, our results suggest a much broader taxonomic occurrence of such an apparently complex cultural behaviour.

Gorilla in our Midst: An online behavioral experiment builder

Abstract: Behavioral researchers are increasingly conducting their studies online, to gain access to large and diverse samples that would be difficult to get in a laboratory environment. However, there are technical access barriers to building experiments online, and web browsers can present problems for consistent timing-an important issue with reaction-time-sensitive measures. For example, to ensure accuracy and test-retest reliability in presentation and response recording, experimenters need a working knowledge of programming languages such as JavaScript. We review some of the previous and current tools for online behavioral research, as well as how well they address the issues of usability and timing. We then present the Gorilla Experiment Builder (gorilla.sc), a fully tooled experiment authoring and deployment platform, designed to resolve many timing issues and make reliable online experimentation open and accessible to a wider range of technical abilities. To demonstrate the platform's aptitude for accessible, reliable, and scalable research, we administered a task with a range of participant groups (primary school children and adults), settings (without supervision, at home, and under supervision, in both schools and public engagement events), equipment (participant's own computer, computer supplied by the researcher), and connection types (personal internet connection, mobile phone 3G/4G). We used a simplified flanker task taken from the attentional network task (Rueda, Posner, & Rothbart, 2004). We replicated the "conflict network" effect in all these populations, demonstrating the platform's capability to run reaction-time-sensitive experiments. Unresolved limitations of running experiments online are then discussed, along with potential solutions and some future features of the platform.