617 research outputs found

    Systems Thinking to Understand National Well-Being from a Human Capital Perspective

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    Well-being has become an important policy goal to replace gross domestic product (GDP) as an indicator of national progress. Several multidimensional metrics and indicators of well-being have been developed mostly based on the four-capital model that includes natural, economic, human and social capital. These multidimensional measures of well-being, however, are highly categorical and lack a systems perspective that focuses on underlying mechanisms of the metrics and the interconnections between them. This study aims at bringing a systems thinking approach to understanding and measuring national well-being, particularly from a human capital perspective. For this purpose, we employ a qualitative systems mapping approach and identify the direct or indirect relationships between the well-being indicators related to human capital. The results show that the human capital system is governed by several reinforcing feedback loops through economic progress, health and life expectancy, which gives a central role to human capital to enhance well-being. There are balancing loops, however, that may have adverse effects on human capital formation and well-being, for instance through migration and ageing. Future studies can focus on the other three subsystems in the four-capital model, and on quantifying the relationships between different dimensions of well-being

    Acceptability, reliability, validity and responsiveness of the Turkish version of WOMAC osteoarthritis index

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    SummaryObjectiveTo evaluate the acceptability, reliability, validity and responsiveness of the Turkish version of Western Ontario and McMaster Universities (WOMAC) osteoarthritis (OA) index in physiotherapy outpatient practice in Turkey.MethodData were obtained from 72 patients with OA of the knee. They were asked to answer two disease-specific questionnaires (WOMAC LK 3.1 and Lequesne-Algofunctional Index of Severity for the knee) and one generic instrument (Medical Outcomes study SF-36 Survey-SF-36). Acceptability was assessed in terms of refusal rate, rates of missing responses, and administration time. Reliability was assessed using Cronbach's alpha. Content validity was assessed by examining the floor and ceiling effects, and skew of the distributions. Convergent and divergent validity was assessed by examining the Pearson's correlation coefficients. Responsiveness was determined by examining effect size (ES), standardized response means (SRM) and P values generated using Wilcoxon's test.ResultsThe overall response rate was 100%. Alpha values for all WOMAC subscales exceeded the value of 0.70 at both baseline and follow-up assessments. Frequency distributions of scores were symmetrical. Subscales had negligible floor and ceiling effects. Both pain and physical function subscales were fairly correlated with the subscales measuring similar constructs of SF-36, whereas they were weakly correlated with other dimensions of SF-36. A good correlation was obtained between WOMAC total and Lequesne index. The pain and physical function subscales of WOMAC index were the most responsive subscales.ConclusionThe Turkish WOMAC OA index is acceptable, valid, reliable and responsive for use in Turkish patients with knee OA

    Diversifying models for analysing global change scenarios and sustainability pathways

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    Non-technical summary Models are increasingly used to inform the transformation of human–Earth systems towards a sustainable future, aligned with the sustainable development goals (SDGs). We argue that a greater diversity of models ought to be used for sustainability analysis to better address complexity and uncertainty. We articulate the steps to model global change socioeconomic and climatic scenarios with new models. Through these steps, we generate new scenario projections using a human–Earth system dynamics model. Our modelling brings new insights about the sensitivity of sustainability trends to future uncertainty and their alignment with or divergence from previous model-based scenario projections. Technical summary The future uncertainty and complexity of alternative socioeconomic and climatic scenarios challenge the model-based analysis of sustainable development. Obtaining robust insights requires a systematic processing of uncertainty and complexity not only in input assumptions, but also in the diversity of model structures that simulates the multisectoral dynamics of human and Earth system interactions. Here, we implement the global change scenarios, that is, the shared socioeconomic pathways and the representative concentration pathways, in a feedback-rich, integrated assessment model (IAM) of human–Earth system dynamics, called FeliX, to serve two aims: (1) to provide modellers with well-defined steps for the adoption of established scenarios in new IAMs and (2) to explore the impacts of model uncertainty and its structural complexity on the projection of these scenarios for sustainable development. Our modelling shows internally consistent scenario storylines across sectors, yet with quantitatively different realisations of these scenarios compared to other IAMs due to the new model's structural complexity. The results highlight the importance of enumerating global change scenarios and their uncertainty exploration with a diversity of models of different input assumptions and structures to capture a wider variety of future possibilities and sustainability indicators. Social media summary New study highlights the importance of global change scenario analysis with new, SDG-focused IAMs

    Optimization of double pulse pumping for Ni-like Sm x-ray lasers

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    We report a systematic study of double pulse pumping of the Ni-like Sm x-ray laser at 73 Angstrom, currently the shortest wavelength saturated x-ray laser. It is found that the Sm x-ray laser output can change by orders of magnitude when the intensity ratio of the pumping pulses and their relative delay are varied. Optimum pumping conditions are found and interpreted in terms of a simple model. (C) 1999 American Institute of Physics. [S0021-8979(99)07102-9]

    Investigating global diet change dynamics by linking models of human behavior to IAMs

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    Sign.: a\p4\s, B\p4\s, C\p2\s, A-Z\p4\s, 2A-2X\p4\sApostillas marginalesPort. con orla calc.: "J.X.º in. y g."Cabecera calc. en A\s1\p: "Ximeno f."Contiene: Doña Urraca, hija de don Alonso Sexto ; y Don Alonso Séptimo, emperador de las España

    Limits of ultra-high-precision optical astrometry: Stellar surface structures

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    We investigate the astrometric effects of stellar surface structures as a practical limitation to ultra-high-precision astrometry, e.g. in the context of exoplanet searches, and to quantify the expected effects in different regions of the HR-diagram. Stellar surface structures are likely to produce fluctuations in the integrated flux and radial velocity of the star, as well as a variation of the observed photocentre, i.e. astrometric jitter, and closure phase. We use theoretical considerations supported by Monte Carlo simulations to derive statistical relations between the corresponding astrometric, photometric, and radial-velocity effects. For most stellar types the astrometric jitter due to stellar surface structures is expected to be of order 10 micro-AU or greater. This is more than the astrometric displacement typically caused by an Earth-size exoplanet in the habitable zone, which is about 1-4 micro-AU for long-lived main-sequence stars. Only for stars with extremely low photometric variability (<0.5 mmag) and low magnetic activity, comparable to that of the Sun, will the astrometric jitter be of order 1 micro-AU, suffcient to allow the astrometric detection of an Earth-sized planet in the habitable zone. While stellar surface structure may thus seriously impair the astrometric detection of small exoplanets, it has in general negligible impact on the detection of large (Jupiter-size) planets and on the determination of stellar parallax and proper motion. From the starspot model we also conclude that the commonly used spot filling factor is not the most relevant parameter for quantifying the spottiness in terms of the resulting astrometric, photometric and radial-velocity variations.Comment: 12 pages, 4 figures, submitted to A&

    Aperiodic optical variability of intermediate polars - cataclysmic variables with truncated accretion disks

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    We study the power spectra of the variability of seven intermediate polars containing magnetized asynchronous accreting white dwarfs, XSS J00564+4548,IGR J00234+6141, DO Dra, V1223 Sgr, IGR J15094-6649, IGR J16500-3307 and IGR J17195-4100, in the optical band and demonstrate that their variability can be well described by a model based on fluctuations propagating in a truncated accretion disk. The power spectra have breaks at Fourier frequencies, which we associate with the Keplerian frequency of the disk at the boundary of the white dwarfs' magnetospheres. We propose that the properties of the optical power spectra can be used to deduce the geometry of the inner parts of the accretion disk, in particular: 1) truncation radii of the magnetically disrupted accretion disks in intermediate polars, 2) the truncation radii of the accretion disk in quiescent states of dwarf novaeComment: Accepted for publication in A&

    Feedbacks and social tipping: A dynamic systems approach to rapid decarbonization

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    Social tipping points are promising levers for accelerating progress towards net-zero greenhouse gas emission targets. They describe how social, political, economic or technological systems can move rapidly into a new state if cascading positive feedback mechanisms are triggered. Analysing the potential for social tipping requires considering the inherent complexity of social systems and their feedbacks. Here, drawing on insights from an expert elicitation workshop, we outline a dynamic systems approach that entails i) a systems outlook involving interconnected feedback mechanisms alongside cross-system and cross-scale interactions, ii) directed data collection efforts to provide empirical evidence and monitoring of social tipping dynamics, and iii) global, integrated, descriptive modelling to project future dynamics and provide ex-ante evidence for interventions aiming to trigger positive feedback mechanisms. We argue how and why this approach will strengthen the climate policy relevance of research on social tipping
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