19 research outputs found

    Frameless-Finding and Refining A Sampling Frame for Surveying Recreational Fisheries: Lessons from Estimating Swedish Harvest of Western Baltic Cod

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    To achieve sustainable fisheries, advice to management should be based on reliable science and unbiased data. Attaining quality data (i.e. precise and unbiased) on recreational fishing can be challenging, particularly when prior knowledge of the sector is limited and a proper sample frame of recreational fishers or vessels does not exist. In this study, a registry of access points was constructed for the Swedish south–west coast and used as a spatial sample frame in determining both effort and catches of the private boat fishery. Sampling dates, times for sampling, and access points visited were selected using probabilistic methods, ensuring unbiased results. The final multi-stage sampling design involved multiple strata, clusters, and probability selection methods and enabled first-time estimation of Swedish recreational landings of western Baltic cod by private boats to be used in stock assessment. Concurrent data collection covering aspects such as boat counts at access points, provided additional information on e.g. activity patterns. That additional information opens possibilities to refine the design of the original survey and optimize the sampling effort towards different goals, such as other fished resources. In this paper, we reflect on the challenges that limitations in initial information poses to the design and deployment of a new recreational fisheries survey. We suggest ways, whereby indirect sampling frames can be developed from initially incomplete or limited information to access the fishers and their catch. Our experience shows that, despite initial frame and knowledge limitations, full probabilistic methods are worth considering in data limited scenarios and that the design-based point estimates and variances they provide on recreational fishing effort and catches are useful in guiding initial management and the next steps of survey improvement

    Total aerosol effect: radiative forcing or radiative flux perturbation?

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    Uncertainties in aerosol radiative forcings, especially those associated with clouds, contribute to a large extent to uncertainties in the total anthropogenic forcing. The interaction of aerosols with clouds and radiation introduces feedbacks which can affect the rate of precipitation formation. In former assessments of aerosol radiative forcings, these effects have not been quantified. Also, with global aerosol-climate models simulating interactively aerosols and cloud microphysical properties, a quantification of the aerosol forcings in the traditional way is difficult to define properly. Here we argue that fast feedbacks should be included because they act quickly compared with the time scale of global warming. We show that for different forcing agents (aerosols and greenhouse gases) the radiative forcings as traditionally defined agree rather well with estimates from a method, here referred to as radiative flux perturbations (RFP), that takes these fast feedbacks and interactions into account. Based on our results, we recommend RFP as a valid option to compare different forcing agents, and to compare the effects of particular forcing agents in different models.ISSN:1680-7375ISSN:1680-736

    Total aerosol effect: radiative forcing or radiative flux perturbation?

    Get PDF
    Uncertainties in aerosol radiative forcings, especially those associated with clouds, contribute to a large extent to uncertainties in the total anthropogenic forcing. The interaction of aerosols with clouds and radiation introduces feedbacks which can affect the rate of precipitation formation. In former assessments of aerosol radiative forcings, these effects have not been quantified. Also, with global aerosol-climate models simulating interactively aerosols and cloud microphysical properties, a quantification of the aerosol forcings in the traditional way is difficult to define properly. Here we argue that fast feedbacks should be included because they act quickly compared with the time scale of global warming. We show that for different forcing agents (aerosols and greenhouse gases) the radiative forcings as traditionally defined agree rather well with estimates from a method, here referred to as radiative flux perturbations (RFP), that takes these fast feedbacks and interactions into account. Based on our results, we recommend RFP as a valid option to compare different forcing agents, and to compare the effects of particular forcing agents in different models

    Total aerosol effect: radiative forcing or radiative flux perturbation?

    No full text
    Uncertainties in aerosol radiative forcings, especially those associated with clouds, contribute to a large extent to uncertainties in the total anthropogenic forcing. The interaction of aerosols with clouds and radiation introduces feedbacks which can affect the rate of precipitation formation. In former assessments of aerosol radiative forcings, these effects have not been quantified. Also, with global aerosol-climate models simulating interactively aerosols and cloud microphysical properties, a quantification of the aerosol forcings in the traditional way is difficult to define properly. Here we argue that fast feedbacks should be included because they act quickly compared with the time scale of global warming. We show that for different forcing agents (aerosols and greenhouse gases) the radiative forcings as traditionally defined agree rather well with estimates from a method, here referred to as radiative flux perturbations (RFP), that takes these fast feedbacks and interactions into account. Based on our results, we recommend RFP as a valid option to compare different forcing agents, and to compare the effects of particular forcing agents in different models

    Patient expectations of hip and knee joint replacement surgery and postoperative health status

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    AB Objective: To explore the relationship between preoperative patient expectations and postoperative health status in patients undergoing joint replacement surgery, with particular emphasis on the types of expectations held by patients. Methods: Respondents completed the Hospital for Special Surgery (HSS) Hip/Knee Replacement Expectations Questionnaires pre-surgery, in addition to the Western Ontario and McMaster Osteoarthritis Index (WOMAC(TM)) and the Short-Form 36-Item (SF-36) Health Survey and the Arthritis Self-Efficacy Scale. The WOMAC(TM) Index and SF-36 were also completed 3 and 6 months post-surgery. Results: A total of 106 patients (total hip replacement [THR] = 28; total knee replacement [TKR] = 78) completed questionnaires. No differences were seen in overall expectations between males and females or older or younger patients, although some differences between the age groups were seen for individual expectations on the HSS expectations questionnaires. For THR, a higher rating of the importance of expectations was correlated with a lesser improvement in pain from pre-surgery to 3 months post-surgery, whereas for TKR, a higher rating of expectations was associated with a greater improvement in function to 6 months post-surgery. Conclusions: Patients have high expectations of surgery, which are correlated with post-surgery pain and function. Identifying the broad range of expectations may be helpful in preparation for surgery and gaining greater satisfaction with outcomes
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