938 research outputs found

    Media Coverage and Perceived Policy Influence of Environmental Actors: Good Strategy or Pyrrhic Victory?

    Get PDF
    In this article we analyze how media coverage for environmental actors (individual environmental activists and environmental movement organizations) is associated with their perceived policy influence in Canadian climate change policy networks. We conceptualize media coverage as the total number of media mentions an actor received in Canada’s two main national newspapers—the Globe and Mail and National Post. We conceptualize perceived policy influence as the total number of times an actor was nominated by other actors in a policy network as being perceived to be influential in domestic climate change policy making in Canada. Literature from the field of social movements, agenda setting, and policy networks suggests that environmental actors who garner more media coverage should be perceived as more influential in policy networks than actors who garner less coverage. We assess support for this main hypothesis in two ways. First, we analyze how actor attributes (such as the type of actor) are associated with the amount of media coverage an actor receives. Second, we evaluate whether being an environmental actor shapes the association between media coverage and perceived policy influence. We find a negative association between media coverage and perceived policy influence for individual activists, but not for environmental movement organizations. This case raises fundamental theoretical questions about the nature of relations between media and policy spheres, and the efficacy of media for signaling and mobilizing policy influence

    Theory of commensurable magnetic structures in holmium

    Full text link
    The tendency for the period of the helically ordered moments in holmium to lock into values which are commensurable with the lattice is studied theoretically as a function of temperature and magnetic field. The commensurable effects are derived in the mean-field approximation from numerical calculations of the free energy of various commensurable structures, and the results are compared with the extensive experimental evidence collected during the last ten years on the magnetic structures in holmium. In general the stability of the different commensurable structures is found to be in accord with the experiments, except for the tau=5/18 structure observed a few degrees below T_N in a b-axis field. The trigonal coupling recently detected in holmium is found to be the interaction required to explain the increased stability of the tau=1/5 structure around 42 K, and of the tau=1/4 structure around 96 K, when a field is applied along the c-axis.Comment: REVTEX, 31 pages, 7 postscript figure

    Adaptive response and enlargement of dynamic range

    Full text link
    Many membrane channels and receptors exhibit adaptive, or desensitized, response to a strong sustained input stimulus, often supported by protein activity-dependent inactivation. Adaptive response is thought to be related to various cellular functions such as homeostasis and enlargement of dynamic range by background compensation. Here we study the quantitative relation between adaptive response and background compensation within a modeling framework. We show that any particular type of adaptive response is neither sufficient nor necessary for adaptive enlargement of dynamic range. In particular a precise adaptive response, where system activity is maintained at a constant level at steady state, does not ensure a large dynamic range neither in input signal nor in system output. A general mechanism for input dynamic range enlargement can come about from the activity-dependent modulation of protein responsiveness by multiple biochemical modification, regardless of the type of adaptive response it induces. Therefore hierarchical biochemical processes such as methylation and phosphorylation are natural candidates to induce this property in signaling systems.Comment: Corrected typos, minor text revision

    Interplay between distribution of live cells and growth dynamics of solid tumours

    Get PDF
    Experiments show that simple diffusion of nutrients and waste molecules is not sufficient to explain the typical multilayered structure of solid tumours, where an outer rim of proliferating cells surrounds a layer of quiescent but viable cells and a central necrotic region. These experiments challenge models of tumour growth based exclusively on diffusion. Here we propose a model of tumour growth that incorporates the volume dynamics and the distribution of cells within the viable cell rim. The model is suggested by in silico experiments and is validated using in vitro data. The results correlate with in vivo data as well, and the model can be used to support experimental and clinical oncology

    Computerised cognitive behaviour therapy for depression in adolescents: Study protocol for a feasibility randomised controlled trial

    Get PDF
    \ua9 2014, BMJ Publishing Group. All rights reserved. Introduction: The 1 year prevalence of depression in adolescents is about 2%. Treatment with antidepressant medication is not recommended for initial treatment in young people due to concerns over high side effects, poor efficacy and addictive potential. Evidence suggests that cognitive behaviour therapy (CBT) is an effective treatment for depression and is currently one of the main treatment options recommended in adolescents. Given the affinity young people have with information technology they may be treated effectively, more widely and earlier in their illness evolution using computeradministered CBT (CCBT). Currently little is known about the clinical and resource implications of implementing CCBT within the National Health Service for adolescents with low mood/depression. We aim to establish the feasibility of running a fully powered randomised controlled trial (RCT). Methods and analysis: Adolescents aged 12-18 with low mood/depression, (scoring ≥20 on the Mood and Feelings Questionnaire (MFQ)), will be approached to participate. Consenting participants will be randomised to either a CCBT programme (Stressbusters) or accessing selected websites providing information about low mood/depression. The primary outcome measure will be the Beck Depression Inventory (BDI). Participants will also complete generic health measures (EQ5D-Y, HUI2) and resource use questionnaires to examine the feasibility of cost-effectiveness analysis. Questionnaires will be completed at baseline, 4 and 12-month follow-ups. Progress and risk will be monitored via the MFQ administered at each treatment session. The acceptability of a CCBT programme to adolescents; and the willingness of clinicians to recruit participants and of participants to be randomised, recruitment rates, attrition rates and questionnaire completion rates will be collected for feasibility analysis. We will estimate \u27numbers needed\u27 to plan a fully powered RCT of clinical and cost-effectiveness. Ethics and dissemination: The current trial protocol received a favourable ethical opinion from Leeds (West) Research and Ethics Committee. (Reference: 10/H1307/137). Trial registration number: ISRCTN31219579

    Metatranscriptomics reveals diversity of symbiotic interaction and mechanisms of carbon exchange in the marine cyanolichen Lichina pygmaea

    Get PDF
    Lichens are exemplar symbioses based upon carbon exchange between photobionts and their mycobiont hosts. Historically considered a two-way relationship, some lichen symbioses have been shown to contain multiple photobiont partners; however, the way in which these photobiont communities react to environmental change is poorly understood. Lichina pygmaea is a marine cyanolichen that inhabits rocky seashores where it is submerged in seawater during every tidal cycle. Recent work has indicated that L. pygmaea has a complex photobiont community including the cyanobionts Rivularia and Pleurocapsa. We performed rRNA-based metabarcoding and mRNA metatranscriptomics of the L. pygmaea holobiont at high and low tide to investigate community response to immersion in seawater. Carbon exchange in L. pygmaea is a dynamic process, influenced by both tidal cycle and the biology of the individual symbiotic components. The mycobiont and two cyanobiont partners exhibit distinct transcriptional responses to seawater hydration. Sugar-based compatible solutes produced by Rivularia and Pleurocapsa in response to seawater are a potential source of carbon to the mycobiont. We propose that extracellular processing of photobiont-derived polysaccharides is a fundamental step in carbon acquisition by L. pygmaea and is analogous to uptake of plant-derived carbon in ectomycorrhizal symbioses

    Survey of US public attitudes toward pharmacogenetic testing

    Get PDF
    To assess public attitudes and interest in pharmacogenetic (PGx) testing, we conducted a random-digit-dial telephone survey of U.S. adults, achieving a response rate of 42% (n=1139). Most respondents expressed interest in PGx testing to predict mild or serious side effects (73% ±3.29% and 85% ±2.91%, respectively), guide dosing (91%) and assist with drug selection (92%). Younger individuals (ages 18–34) were more likely to be interested in PGx testing to predict serious side effects (vs. ages 55+), as well as Whites, those with a college degree, and who had experienced side effects from medications. However, most respondents (78% ±3.14%) were not likely to have a PGx test if there was a risk that their DNA sample or test result could be shared without their permission. Given differences in interest among some groups, providers should clearly discuss the purpose of testing, alternative testing options (if available), and policies to protect patient privacy and confidentiality
    • …
    corecore