33 research outputs found

    A multi-stakeholder approach to eHealth development: promoting sustained healthy living among cardiovascular patients

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    Background: Healthy living is key in the prevention and rehabilitation of cardiovascular disease (CVD). Yet, supporting and maintaining a healthy lifestyle is exceptionally difficult and people differ in their needs regarding optimal support for healthy lifestyle interventions.Objective: The goals of this study were threefold: to uncover stakeholders' needs and preferences, to translate these to core values, and develop eHealth technology based on these core values. Our primary research question is: What type of eHealth application to support healthy living among people with (a high risk of) CVD would provide the greatest benefit for all stakeholders? Methods: User-centered design principles from the CeHRes roadmap for eHealth development were followed to guide the uncovering of important stakeholder values. Data were synthesized from various qualitative studies (i. e., literature studies, interviews, think-aloud sessions, focus groups) and usability tests (i.e., heuristic evaluation, cognitive walkthrough, think aloud study). We also developed an innovative application evaluation tool to perform a competitor analysis on 33 eHealth applications. Finally, to make sure to take into account all end-users needs and preferences in eHealth technology development, we created personas and a customer journey.Results: We uncovered 10 universal values to which eHealth-based initiatives to support healthy living in the context of CVD prevention and rehabilitation should adhere to (e.g., providing social support, stimulating intrinsic motivation, offering continuity of care). These values were translated to 14 desired core attributes and then prototype designs. Interestingly, we found that the primary attribute of good eHealth technology was not a single intervention principle, but rather that the technology should be in the form of a digital platform disseminating various interventions, i.e., a 'one-stop-shop'.Conclusion: Various stakeholders in the field of cardiovascular prevention and rehabilitation may benefit most from utilizing one personalized eHealth platform that integrates a variety of evidence-based interventions, rather than a new tool. Instead of a one-size-fits-all approach, this digital platform should aid the matchmaking between patients and specific interventions based on personal characteristics and preferences.Cardiolog

    A multi-stakeholder approach to eHealth development: Promoting sustained healthy living among cardiovascular patients

    Get PDF
    Background: Healthy living is key in the prevention and rehabilitation of cardiovascular disease (CVD). Yet, supporting and maintaining a healthy lifestyle is exceptionally difficult and people differ in their needs regarding optimal support for healthy lifestyle interventions. Objective: The goals of this study were threefold: to uncover stakeholders’ needs and preferences, to translate these to core values, and develop eHealth technology based on these core values. Our primary research question is: What type of eHealth application to support healthy living among people with (a high risk of) CVD would provide the greatest benefit for all stakeholders? Methods: User-centered design principles from the CeHRes roadmap for eHealth development were followed to guide the uncovering of important stakeholder values. Data were synthesized from various qualitative studies (i.e., literature studies, interviews, think-aloud sessions, focus groups) and usability tests (i.e., heuristic evaluation, cognitive walkthrough, think aloud study). We also developed an innovative application evaluation tool to perform a competitor analysis on 33 eHealth applications. Finally, to make sure to take into account all end-users needs and preferences in eHealth technology development, we created personas and a customer journey. Results: We uncovered 10 universal values to which eHealth-based initiatives to support healthy living in the context of CVD prevention and rehabilitation should adhere to (e.g., providing social support, stimulating intrinsic motivation, offering continuity of care). These values were translated to 14 desired core attributes and then prototype designs. Interestingly, we found that the primary attribute of good eHealth technology was not a single intervention principle, but rather that the technology should be in the form of a digital platform disseminating various interventions, i.e., a ‘one-stop-shop’. Conclusion: Various stakeholders in the field of cardiovascular prevention and rehabilitation may benefit most from utilizing one personalized eHealth platform that integrates a variety of evidence-based interventions, rather than a new tool. Instead of a one-size-fits-all approach, this digital platform should aid the matchmaking between patients and specific interventions based on personal characteristics and preferences

    « Half dicht, half prose gheordineert » : vers et prose de moyen français en moyen néerlandais

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    In both French-speaking and Dutch-speaking literary cultures of the late Middle Ages, competition between poets produced a collective poetic expertise. To what extent, then, can such competition be identified across the two cultures, in translations of verse or prosimetrum compositions from Middle French into Middle Dutch? An examination of the Dutch translations reveals that verse is both a means to knowledge and an object of knowledge, in the target culture as well as the source culture. The diversity of translations shows that verse is not only a system that translators attempt to master, but also a formal supplement in ways that are unavailable to prose

    Alley coppice—a new system with ancient roots

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    Yield-SAFE: A parameter-sparse, process-based dynamic model for predicting resource capture, growth, and production in agroforestry systems.

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    1. Silvoarable agroforestry (SAF) is the cultivation of trees and arable crops on the same parcel of land. SAF may contribute to modern diversified land use objectives in Europe, such as enhanced biodiversity and productivity, reduced leaching of nitrogen, protection against flooding and erosion, and attractiveness of the landscape. Long-term yield predictions are needed to assess long-term economic profitability of SAF. 2. A model for growth, resource sharing and productivity in agroforestry systems was developed to act as a tool in forecasts of yield, economic optimization of farming enterprises and exploration of policy options for land use in Europe. The model is called Yield- SAFE; from “YIeld Estimator for Long term Design of Silvoarable AgroForestry in Europe”. The model was developed with as few equations and parameters as possible to allow model parameterization under constrained availability of data from long-term experiments. 3. The model consists of seven state equations expressing the temporal dynamics of: (1) tree biomass; (2) tree leaf area; (3) number of shoots per tree; (4) crop biomass; (5) crop leaf area index; (6) heat sum; and (7) soil water content. The main outputs of the model are the growth dynamics and final yields of trees and crops. Daily inputs are temperature, radiation and precipitation. Planting densities, initial biomasses of tree and crop species, and soil parameters must be specified. 4. A parameterization of Yield-SAFE is generated, using published yield tables for tree growth and output from the comprehensive crop simulation model STICS. Analysis of tree and crop growth data from two poplar agroforestry stands in the United Kingdom demonstrates the validity of the modelling concept and calibration philosophy of Yield-SAFE. A sensitivity analysis is presented to elucidate which biological parameters most influence short and long-term productivity and land equivalent ratio. 5. The conceptual model, elaborated in Yield-SAFE, in combination with the outlined procedure for model calibration, offers a valid tool for exploratory land use stu

    Recruitment and attrition of associated plants under a shading crop canopy: Model selection and calibration

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    Associated plant and animal diversity provides ecosystem services within crop production systems. The importance of the maintenance or restoration of diversity is therefore increasingly acknowledged. Here we study the population dynamics of associated annual plants (`weeds¿) during the growth of a crop in a season and introduce a minimal model to characterize the recruitment and attrition of the associated plants under the influence of shading by the crop. A mechanistically based, logistic, light interception model was parameterized with light interception measurements in two single crops (barley and rye) and in mixtures of these cereals with peas. Population dynamics data were collected for the annuals Papaver rhoeas, Centaurea cyanus, Chrysanthemum segetum, and Misopates orontium. A minimal population dynamics model was identified for each annual plant species, using system identification techniques as model selection and calibration. For three of the four species, a two-parameter model consisting of light-dependent recruitment in combination with a constant death rate, explained 75¿96% of the variation in plant densities over the season. Model fit for P. rhoeas improved when a germination delay of 200 °Cd after sowing was included, resulting in a three-parameter model. The developed models have a simple yet biologically meaningful structure and the values of the parameters give a useful summary of the population dynamics of an annual plant population under the influence of the dynamic leaf cover of a shading crop. Further development of these models can contribute to systems design for maintaining plant diversity in crop systems

    Production ecology of agroforestry systems: A minimal mechanistic model and analytical derivation of the land equivalent ratio

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    In this paper, the yield and the land equivalent ratio (LER) of a silvo-arable agroforestry (SAF) system, containing one tree and one crop species, is analyzed analytically using a minimal mechanistic model describing the system dynamics. Light competition between tree and crop is considered using light extinction functions. The tree leaf area is driven by annual increase in the number of leaf-bearing shoots with a seasonal cycle of bud burst, leaf expansion and senescence. The crop leaf area dynamics is driven by the solar radiation, heat sum and the dry matter allocation to the leaves. As a consequence of this, the model consists of six state equations expressing the temporal dynamics of: (1) tree biomass; (2) tree leaf area; (3) number of shoots per tree; (4) crop biomass; (5) crop leaf area index, and (6) heat sum. The main outputs of the model are the growth dynamics and final yields of trees and crops. Daily inputs are temperature and radiation. Planting densities, initial biomass of tree and crop species and growth parameters must be specified. The main parameters are those describing light interception, conversion to dry matter and leaf area. Given the crop cover and the tree parameters, it is shown that under potential growing conditions the land equivalent ratio can be explicitly expressed in terms of these parameters

    Production ecology of agroforestry systems: A minimal mechanistic model and analytical derivation of the land equivalent ratio

    No full text
    In this paper, the yield and the land equivalent ratio (LER) of a silvo-arable agroforestry (SAF) system, containing one tree and one crop species, is analyzed analytically using a minimal mechanistic model describing the system dynamics. Light competition between tree and crop is considered using light extinction functions. The tree leaf area is driven by annual increase in the number of leaf-bearing shoots with a seasonal cycle of bud burst, leaf expansion and senescence. The crop leaf area dynamics is driven by the solar radiation, heat sum and the dry matter allocation to the leaves. As a consequence of this, the model consists of six state equations expressing the temporal dynamics of: (1) tree biomass; (2) tree leaf area; (3) number of shoots per tree; (4) crop biomass; (5) crop leaf area index, and (6) heat sum. The main outputs of the model are the growth dynamics and final yields of trees and crops. Daily inputs are temperature and radiation. Planting densities, initial biomass of tree and crop species and growth parameters must be specified. The main parameters are those describing light interception, conversion to dry matter and leaf area. Given the crop cover and the tree parameters, it is shown that under potential growing conditions the land equivalent ratio can be explicitly expressed in terms of these parameters

    Non-linear Robust Identification: Application to a Thermal Process

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    A system identification approach for developing and parameterising an agroforestry system model under constrained availability of data

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    This paper introduces a system identification approach to overcome the problem of insufficient data when developing and parameterising an agroforestry system model. Typically, for these complex systems the number of available data points from actual systems is less than the number of parameters in a (process-based) model. In this paper, we follow a constrained parameter optimization approach, in which the constraints are found from literature or are given by experts. Given the limited a priori systems knowledge and very limited data sets, after decomposition of the parameter estimation problem and after model adaptation, we were able to produce an acceptable correspondence with validation data from a real-world agroforestry experimen
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