Modelling and experimental investigation of carangiform locomotion for control

We propose a model for planar carangiform swimming based on conservative equations for the interaction of a rigid body and an incompressible fluid. We account for the generation of thrust due to vortex shedding through controlled coupling terms. We investigate the correct form of this coupling experimentally with a robotic propulsor, comparing its observed behavior to that predicted by unsteady hydrodynamics. Our analysis of thrust generation by an oscillating hydrofoil allows us to characterize and evaluate certain families of gaits. Our final swimming model takes the form of a control-affine nonlinear system

The roll-your-own cigarette market in Canada: a cross-sectional exploratory study

<p>Abstract</p> <p>Background</p> <p>Even though the use and prevalence of roll-your-own cigarettes (RYO) has been declining over the past decades, RYO remains important. Given the paucity of research examining RYO use, there is a need to better understand the current and potential future context of RYO use.</p> <p>Methods</p> <p>Data from the 2002 Canadian Tobacco Use Monitoring Survey (CTUMS) were used to examine RYO tobacco use among 23,341 Canadians aged 15 and older. Logistic regression models were conducted to examine factors which differentiate smokers who smoke RYO tobacco all of the time, most of the time or sometimes from smokers who do not smoke RYO tobacco.</p> <p>Results</p> <p>We found that 17% (n = 925,000) of current smokers in Canada reported smoking RYO. When compared to manufactured cigarette (MC) smokers, RYO users were heavier smokers, more addicted to nicotine, and less likely to consider quitting smoking. Lower income smokers were more likely to smoke RYO tobacco compared to smokers with high income. Conversely, smokers who had completed secondary school or university were less likely to smoke RYO tobacco compared to smokers who had not completed secondary school.</p> <p>Conclusion</p> <p>This study demonstrates that RYO tobacco use is not a negligible problem within Canada and provides valuable new insight for developing future tobacco control initiatives for this population of smokers.</p

Countdown to the Future

At the NASA Ames Research Center in California, the next generation of space biologists are working to understand the effects of long duration space flight on model organisms, and are developing ways to protect the health of future astronauts

The Cooperative Participatory Evaluation of Renewable Technologies on Ecosystem Services (CORPORATES)

Publisher PD

Boys and girls prefer hyper-muscular male action figures over normally-muscular action figures: Evidence that children have internalized the muscular male body ideal

We sought evidence of internalization of the muscular ideal body among boys and girls by comparing their preferences for hyper-muscular action figures versus their normally-muscular counterparts. Children observed pairings of action figures and reported their preference. Most boys and girls significantly preferred the hyper-muscular figures, and were more likely to provide a physical reason for their preference (e.g., more muscular) than children who preferred the normally-muscular figures. Sex did not affect rates of preference for preferring the hyper-muscular figures, suggesting physical reasons were the main reason why both boys and girls preferred the hyper-muscular figures. Figure preference differed significantly as a function of sex; boys were significantly more likely to report a preference for the hyper-muscular figures (90.3%) than girls (80.7%), ?2(1, N = 347) = 6.53, p = .011. The results tentatively point to internalization of the muscular ideal body among both boys and girls. Clinicians might consider exploring and dismantling internalization-related beliefs among child clients

Utilización de los resultados de una evaluación nacional del rendimiento académico

Centra su atención en la redacción de informes y en el uso de los datos obtenidos en una evaluación nacional con el objetivo final de mejorar la calidad del aprendizaje de los estudiantes. Está destinado a dos tipos principales de lectores: (a) aquellos que tienen responsabilidad en la preparación de informes de evaluación y en la comunicación y la divulgación de los resultados y (b) los usuarios de esos resultados

The bottom mixed layer depth as an indicator of subsurface Chlorophyll a distribution

Acknowledgements The authors thank Marine Scotland Science for providing the CTD data. Financial support This research has been supported by a MarCRF (Marine Collaboration Research Forum, jointly sponsored by the University of Aberdeen and Marine Scotland Science) PhD grant awarded to Arianna Zampollo.Peer reviewedPublisher PD

Diagramming social practice theory:An interdisciplinary experiment exploring practices as networks

Achieving a transition to a low-carbon energy system is now widely recognised as a key challenge facing humanity. To date, the vast majority of research addressing this challenge has been conducted within the disciplines of science, engineering and economics utilising quantitative and modelling techniques. However, there is growing awareness that meeting energy challenges requires fundamentally socio-technical solutions and that the social sciences have an important role to play. This is an interdisciplinary challenge but, to date, there remain very few explorations of, or reflections on, interdisciplinary energy research in practice. This paper seeks to change that by reporting on an interdisciplinary experiment to build new models of energy demand on the basis of cutting-edge social science understandings. The process encouraged the social scientists to communicate their ideas more simply, whilst allowing engineers to think critically about the embedded assumptions in their models in relation to society and social change. To do this, the paper uses a particular set of theoretical approaches to energy use behaviour known collectively as social practice theory (SPT) - and explores the potential of more quantitative forms of network analysis to provide a formal framework by means of which to diagram and visualize practices. The aim of this is to gain insight into the relationships between the elements of a practice, so increasing the ultimate understanding of how practices operate. Graphs of practice networks are populated based on new empirical data drawn from a survey of different types (or variants) of laundry practice. The resulting practice networks are analysed to reveal characteristics of elements and variants of practice, such as which elements could be considered core to the practice, or how elements between variants overlap, or can be shared. This promises insights into energy intensity, flexibility and the rootedness of practices (i.e. how entrenched/ established they are) and so opens up new questions and possibilities for intervention. The novelty of this approach is that it allows practice data to be represented graphically using a quantitative format without being overly reductive. Its usefulness is that it is readily applied to large datasets, provides the capacity to interpret social practices in new ways, and serves to open up potential links with energy modeling. More broadly, a significant dimension of novelty has been the interdisciplinary approach, radically different to that normally seen in energy research. This paper is relevant to a broad audience of social scientists and engineers interested in integrating social practices with energy engineering