Polymer Adsorption on Curved Surfaces: Finite chain length corrections

The structural properties of polymers adsorbed onto a surface have been widely investigated using self-consistent mean-field theories. Recently, analytical mean-field theories have been applied to study polymer adsorption on curved surfaces but all in the context of the ground state dominance approximation in which the polymer chain length (N) is essentially infinite. Using an expression for the free energy by Semenov, we determine leading order (in 1/N) corrections due to the finiteness of the polymer chain length on surface tension, spontaneous curvature, and rigidity constants.Comment: 24 pages, 7 figures. Accepted for publication in Macromolecule

Using participatory approaches with children to better understand their physical activity behaviour

Aims and objectives: The importance of childhood physical activity is widely recognised. Helping children to articulate their opinions is a crucial factor in improving their health and well-being, yet the field is predominantly focused on adult-led quantitative methods and lacks deeper understanding from a child perspective. Methods: This paper draws on experiences from a Danish study in which children depicted their physical activity behaviour in go-along group interviews in schoolyards (n = 111), and a Scottish study in which children photographed or drew meaningful places and discussed physical activity in these places (n = 25). Results: The benefits and challenges associated with using participatory methods to understand how children perceive the environment in relation to their physical activity behaviour are described. Conclusion: Findings contribute to the literature by suggesting that participatory approaches are valuable in capturing children’s perceptions of physical activity behaviour in outdoor environments

Service Production and Patient Satisfaction in Primary Care

Context: The institutional setting for the study was the primary physician service in Norway, where there is a regular general practitioner scheme. Each inhabitant has a statutory right to be registered with a regular general practitioner. There are large differences between physicians in service production. Objective: We studied whether difference in services production between physicians has an effect on how satisfied patients are with the services that are provided. Methodology: Data about patient satisfaction were obtained from a survey of a representative sample of the population. We obtained data about how satisfied the respondents were with waiting time to get an appointment and with two aspects of the quality of care they actually received: the amount of time the physician spent with them, and to what extent they perceived that the physician took their medical problems seriously. The survey data were merged with data on service production for the primary physician that the respondent was registered with. Service production was measured as the number of consultations per person on the list, and as the number of laboratory tests per consultation. Results: There was a positive and relatively strong association between the level of service production of the general practitioners and patient satisfaction with waiting time for a consultation. The association was weaker for satisfaction with the quality of care the respondents actually received. Conclusion: A high level of service production can be justified, since it increases patient satisfaction, particularly satisfaction with access to services.primary physician services; patient satisfaction; service production; access

Who Has Seen What When? Pornography’s Contribution to the Social Construction of Sexuality During Childhood and Adolescence

Pornography has a ubiquitous place in contemporary Canadian Society. With or without intention, children and youth are frequently exposed to pornographic images and depictions. There is little research detailing the types of exposure that occur and the impact of said exposure on this population. Through a detailed survey administered to approximately 450 first-year college and university students in Ontario, this retrospective and exploratory study answers the query, “when and to what type of pronography are children and young adults exposed and how does this exposure relate to subsequent sexual behaviours and attitudes?” Following a deatiled escription of pornography exposure, indicating the source, medium, and the content, current pornographic consumption is documented and related to sexual practices and attitudes. Significant relationships were detected between early pornographic exposure and early engagement in sexual activities. Parental attitudes and behaviour were found to be related to both early exposure and subsequent pornography use

A kinetic model describing the processivity of Myosin-V

The precise details of how myosin-V coordinates the biochemical reactions and mechanical motions of its two head elements to engineer effective processive molecular motion along actin filaments remain unresolved. We compare a quantitative kinetic model of the myosin-V walk, consisting of five basic states augmented by two further states to allow for futile hydrolysis and detachments, with experimental results for run lengths, velocities, and dwell times and their dependence on bulk nucleotide concentrations and external loads in both directions. The model reveals how myosin-V can use the internal strain in the molecule to synchronize the motion of the head elements. Estimates for the rate constants in the reaction cycle and the internal strain energy are obtained by a computational comparison scheme involving an extensive exploration of the large parameter space. This scheme exploits the fact that we have obtained analytic results for our reaction network, e.g., for the velocity but also the run length, diffusion constant, and fraction of backward steps. The agreement with experiment is often reasonable but some open problems are highlighted, in particular the inability of such a general model to reproduce the reported dependence of run length on ADP concentration. The novel way that our approach explores parameter space means that any confirmed discrepancies should give new insights into the reaction network model