106 research outputs found

    An updated version of a gap-free monthly mean zonal mean ozone database

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    An updated and improved version of a global, vertically resolved, monthly mean zonal mean ozone database has been calculated – hereafter referred to as the BSVertOzone (Bodeker Scientific Vertical Ozone) database. Like its predecessor, it combines measurements from several satellite-based instruments and ozone profile measurements from the global ozonesonde network. Monthly mean zonal mean ozone concentrations in mixing ratio and number density are provided in 5° latitude bins, spanning 70 altitude levels (1 to 70km), or 70 pressure levels that are approximately 1km apart (878.4 to 0.046hPa). Different data sets or “tiers” are provided: Tier 0 is based only on the available measurements and therefore does not completely cover the whole globe or the full vertical range uniformly; the Tier 0.5 monthly mean zonal means are calculated as a filled version of the Tier 0 database where missing monthly mean zonal mean values are estimated from correlations against a total column ozone (TCO) database. The Tier 0.5 data set includes the full range of measurement variability and is created as an intermediate step for the calculation of the Tier 1 data where a least squares regression model is used to attribute variability to various known forcing factors for ozone. Regression model fit coefficients are expanded in Fourier series and Legendre polynomials (to account for seasonality and latitudinal structure, respectively). Four different combinations of contributions from selected regression model basis functions result in four different Tier 1 data sets that can be used for comparisons with chemistry–climate model (CCM) simulations that do not exhibit the same unforced variability as reality (unless they are nudged towards reanalyses). Compared to previous versions of the database, this update includes additional satellite data sources and ozonesonde measurements to extend the database period to 2016. Additional improvements over the previous version of the database include the following: (i) adjustments of measurements to account for biases and drifts between different data sources (using a chemistry-transport model, CTM, simulation as a transfer standard), (ii) a more objective way to determine the optimum number of Fourier and Legendre expansions for the basis function fit coefficients, and (iii) the derivation of methodological and measurement uncertainties on each database value are traced through all data modification steps. Comparisons with the ozone database from SWOOSH (Stratospheric Water and OzOne Satellite Homogenized data set) show good agreement in many regions of the globe. Minor differences are caused by different bias adjustment procedures for the two databases. However, compared to SWOOSH, BSVertOzone additionally covers the troposphere. Version 1.0 of BSVertOzone is publicly available at https://doi.org/http://doi.org/10.5281/zenodo.1217184

    Initial steps towards an evidence-based classification system for golfers with a physical impairment

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    Purpose: The present narrative review aims to make a first step towards an evidence-based classification system in handigolf following the International Paralympic Committee (IPC). It intends to create a conceptual framework of classification for handigolf and an agenda for future research. Method: Pubmed was searched on three themes: “Classification in Paralympic sports”, “Performance determining factors in golf” and “Impact of impairments on golf performance”. IPC-regulations were gathered on the IPC-website and their official publications. Results: In developing a classification system conform IPC-regulations, the main challenge is to identify the activity limitation caused by the impairment, not influenced by training, talent or motivation. Timing, accuracy and control, work per joint, range of motion, balance and flexibility are important performance determining factors in abled-bodied golf and should be considered when determining activity limitations in handigolf. Only five articles on handigolf were found, mainly addressing the asymmetric golf movement. Based on the present review, a conceptual framework for classification was developed, while a future research agenda was designated. The conceptual framework presents factors that are essential for sports performance categorized under “technology”, “interface” and “athlete characteristics”. It also includes impairment related factors essential for determining eligibility and classification. Ideally, measures to be used during classification need to be resistant against training, natural development of the athlete’s talent and motivational changes. Conclusions: The conceptual framework and a multidimensional scientific research agenda will support further development of the knowledge base required for an evidence-based classification in handigolf, including multi-level analysis of player statistics, experimental analyses of biomechanics and modeling studies.Implications for Rehabilitation The main challenge in developing an evidence-based classification system conform IPC-regulations is defining eligibility criteria and sport classes based on activity limitation caused by only the impairment and not affected by training, talent and motivation. It is expected that a transparent classification system, a lively competition and admission to the Paralympic program will further promote participation in disabled golf. Timing, accuracy and control, work per joint, range of motion, balance and flexibility are of greater importance for golf performance in able-bodied golfers and expected to be of interest to incorporate in classification for handigolf. Side and level of amputation influence activity limitation in the asymmetric golf movement, and should be incorporated in classification. The proposed conceptual framework is fundamental to the research agenda that must further generate the knowledge-base to determine activity limitations caused by different impairments in handigolf and may serve as a guideline for other Paralympic sports in the development of evidence-based classification

    Mitochondrial Structure, Function and Dynamics Are Temporally Controlled by c-Myc

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    Although the c-Myc (Myc) oncoprotein controls mitochondrial biogenesis and multiple enzymes involved in oxidative phosphorylation (OXPHOS), the coordination of these events and the mechanistic underpinnings of their regulation remain largely unexplored. We show here that re-expression of Myc in myc−/− fibroblasts is accompanied by a gradual accumulation of mitochondrial biomass and by increases in membrane polarization and mitochondrial fusion. A correction of OXPHOS deficiency is also seen, although structural abnormalities in electron transport chain complexes (ETC) are not entirely normalized. Conversely, the down-regulation of Myc leads to a gradual decrease in mitochondrial mass and a more rapid loss of fusion and membrane potential. Increases in the levels of proteins specifically involved in mitochondrial fission and fusion support the idea that Myc affects mitochondrial mass by influencing both of these processes, albeit favoring the latter. The ETC defects that persist following Myc restoration may represent metabolic adaptations, as mitochondrial function is re-directed away from producing ATP to providing a source of metabolic precursors demanded by the transformed cell

    What Lies behind the Wish to Hasten Death? A Systematic Review and Meta-Ethnography from the Perspective of Patients

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    BACKGROUND: There is a need for an in-depth approach to the meaning of the wish to hasten death (WTHD). This study aims to understand the experience of patients with serious or incurable illness who express such a wish. METHODS AND FINDINGS: Systematic review and meta-ethnography of qualitative studies from the patient's perspective. Studies were identified through six databases (ISI, PubMed, PsycINFO, CINAHL, CUIDEN and the Cochrane Register of Controlled Trials), together with citation searches and consultation with experts. Finally, seven studies reporting the experiences of 155 patients were included. The seven-stage Noblit and Hare approach was applied, using reciprocal translation and line-of-argument synthesis. Six main themes emerged giving meaning to the WTHD: WTHD in response to physical/psychological/spiritual suffering, loss of self, fear of dying, the desire to live but not in this way, WTHD as a way of ending suffering, and WTHD as a kind of control over one's life ('having an ace up one's sleeve just in case'). An explanatory model was developed which showed the WTHD to be a reactive phenomenon: a response to multidimensional suffering, rather than only one aspect of the despair that may accompany this suffering. According to this model the factors that lead to the emergence of WTHD are total suffering, loss of self and fear, which together produce an overwhelming emotional distress that generates the WTHD as a way out, i.e. to cease living in this way and to put an end to suffering while maintaining some control over the situation. CONCLUSIONS: The expression of the WTHD in these patients is a response to overwhelming emotional distress and has different meanings, which do not necessarily imply a genuine wish to hasten one's death. These meanings, which have a causal relationship to the phenomenon, should be taken into account when drawing up care plans

    Senescent cells as a source of inflammatory factors for tumor progression

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    Cellular senescence, which is associated with aging, is a process by which cells enter a state of permanent cell cycle arrest, therefore constituting a potent tumor suppressive mechanism. Recent studies show that, despite the beneficial effects of cellular senescence, senescent cells can also exert harmful effects on the tissue microenvironment. The most significant of these effects is the acquisition of a senescent-associated secretory phenotype (SASP), which entails a striking increase in the secretion of pro-inflammatory cytokines. Here, we summarize our knowledge of the SASP and the impact it has on tissue microenvironments and ability to stimulate tumor progression
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