172 research outputs found

    Images of the Nordic welfare model : Historical layers and ambiguities

    Get PDF
    Throughout the twentieth century, the Nordic welfare model has been attributed different characteristics and connotations. The notion of a Nordic model was constructed during the gradual transformation of the five Nordic nation states into welfare states. We argue that this can be described as a ‘modelization’ process driven by national and regional interests articulated in an international context. We focus on four historical phases: the formative phase of modern social policy in the late nineteenth and early twentieth century, the interwar period, the Cold War period, and the ongoing post-Cold War era. In the concluding discussion, we explain the stickiness of the image of a Nordic model by highlighting several dualisms in the uses of the concept that allowed not only for the settling of conflicting interests but also for the continuation over a century of both continuities and discontinuities.Peer reviewe

    Existence of a stable polarized vacuum in the Bogoliubov-Dirac-Fock approximation

    Full text link
    According to Dirac's ideas, the vacuum consists of infinitely many virtual electrons which completely fill up the negative part of the spectrum of the free Dirac operator D0D^0. In the presence of an external field, these virtual particles react and the vacuum becomes polarized. In this paper, following Chaix and Iracane ({\it J. Phys. B}, 22, 3791--3814, 1989), we consider the Bogoliubov-Dirac-Fock model, which is derived from no-photon QED. The corresponding BDF-energy takes the polarization of the vacuum into account and is bounded from below. A BDF-stable vacuum is defined to be a minimizer of this energy. If it exists, such a minimizer is solution of a self-consistent equation. We show the existence of a unique minimizer of the BDF-energy in the presence of an external electrostatic field, by means of a fixed-point approach. This minimizer is interpreted as the polarized vacuum.Comment: final version, to appear in Commun. Math. Phy

    Changes in plant diversity in a water‑limited and isolated high‑mountain range (Sierra Nevada, Spain)

    Get PDF
    Open Access funding provided by University of Natural Resources and Life Sciences Vienna (BOKU). This study was funded by the Austrian Academy of Sciences (project MEDIALPS-Disentangling anthropogenic drivers of climate change impacts on alpine plant species: Alps vs. Mediterranean mountains).Supplementary Information The online version contains supplementary material available at https ://doi.org/10.1007/s0003 5-021-00246 -x.We thank Manfred Bardy-Durchhalter for managing the database, Imran Nadeem for discussing climate data preparation, and National Park and Andalusian Environmental Agency staff for their assistance in the field in 2015 and 2019, and answering our questions.Climate change impacts are of a particular concern in small mountain ranges, where cold-adapted plant species have their optimum zone in the upper bioclimatic belts. This is commonly the case in Mediterranean mountains, which often harbour high numbers of endemic species, enhancing the risk of biodiversity losses. This study deals with shifts in vascular plant diversity in the upper zones of the Sierra Nevada, Spain, in relation with climatic parameters during the past two decades. We used vegetation data from permanent plots of three surveys of two GLORIA study regions, spanning a period of 18 years (2001–2019); ERA5 temperature and precipitation data; and snow cover durations, derived from on-site soil temperature data. Relationships between diversity patterns and climate factors were analysed using GLMMs. Species richness showed a decline between 2001 and 2008, and increased thereafter. Species cover increased slightly but significantly, although not for endemic species. While endemics underwent cover losses proportional to non-endemics, more widespread shrub species increased. Precipitation tended to increase during the last decade, after a downward trend since 1960. Precipitation was positively related to species richness, colonisation events, and cover, and negatively to disappearance events. Longer snow cover duration and rising temperatures were also related to increasing species numbers, but not to cover changes. The rapid biotic responses of Mediterranean alpine plants indicate a tight synchronisation with climate fluctuations, especially with water availability. Thus, it rather confirms concerns about biodiversity losses, if projections of increasing temperature in combination with decreasing precipitation hold true.University of Natural Resources and Life Sciences Vienna (BOKU) - Austrian Academy of Science

    Global health burden of ambient PM2.5 and the contribution of anthropogenic black carbon and organic aerosols

    Get PDF
    Chronic exposure to fine particulate matter (PM2.5) poses a major global health risk, commonly assessed by assuming equivalent toxicity for different PM2.5 constituents. We used a data-informed global atmospheric model and recent exposure-response functions to calculate the health burden of ambient PM2.5 from ten source categories. We estimate 4.23 (95% confidence interval 3.0-6.14) million excess deaths annually from the exposure to ambient PM2.5. We distinguished contributions and major sources of black carbon (BC), primary organic aerosols (POA) and anthropogenic secondary organic aerosols (aSOA). These components make up to similar to 20% of the total PM2.5 in South and East Asia and East Africa. We find that domestic energy use by the burning of solid biofuels is the largest contributor to ambient BC, POA and aSOA globally. Epidemiological and toxicological studies indicate that these compounds may be relatively more hazardous than other PM2.5 compounds such as soluble salts, related to their high potential to inflict oxidative stress. We performed sensitivity analyses by considering these species to be more harmful compared to other compounds in PM2.5, as suggested by their oxidative potential using a range of potential relative risks. These analyses show that domestic energy use emerges as the leading cause of excess mortality attributable to ambient PM2.5, notably in Asia and Africa. We acknowledge the uncertainties inherent in our assumed enhanced toxicity of the anthropogenic organic and BC aerosol components, which suggest the need to better understand the mechanisms and magnitude of the associated health risks and the consequences for regulatory policies. However our assessment of the importance of emissions from domestic energy use as a cause of premature mortality is robust to a range of assumptions about the magnitude of the excess risk.Peer reviewe

    Clinical correlates of anti-SARS-CoV-2 antibody profiles in Spanish COVID-19 patients from a high incidence region

    Get PDF
    Laboratory testing for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) consists of two pillars: the detection of viral RNA via rt-PCR as the diagnostic gold standard in acute cases, and the detection of antibodies against SARS-CoV-2. However, concerning the latter, questions remain about their diagnostic and prognostic value and it is not clear whether all patients develop detectable antibodies. We examined sera from 347 Spanish COVID-19 patients, collected during the peak of the epidemic outbreak in Spain, for the presence of IgA and IgG antibodies against SARS-CoV-2 and evaluated possible associations with age, sex and disease severity (as measured by duration of hospitalization, kind of respiratory support, treatment in ICU and death). The presence and to some degree the levels of anti-SARS-CoV-2 antibodies depended mainly on the amount of time between onset of symptoms and the collection of serum. A subgroup of patients did not develop antibodies at the time of sample collection. Compared to the patients that did, no differences were found. The presence and level of antibodies was not associated with age, sex, duration of hospitalization, treatment in the ICU or death. The case-fatality rate increased exponentially with older age. Neither the presence, nor the levels of anti-SARS-CoV-2 antibodies served as prognostic markers in our cohort. This is discussed as a possible consequence of the timing of the sample collection. Age is the most important risk factor for an adverse outcome in our cohort. Some patients appear not to develop antibodies within a reasonable time frame. It is unclear, however, why that is, as these patients differ in no respect examined by us from those who developed antibodies

    Ground State and Charge Renormalization in a Nonlinear Model of Relativistic Atoms

    Full text link
    We study the reduced Bogoliubov-Dirac-Fock (BDF) energy which allows to describe relativistic electrons interacting with the Dirac sea, in an external electrostatic potential. The model can be seen as a mean-field approximation of Quantum Electrodynamics (QED) where photons and the so-called exchange term are neglected. A state of the system is described by its one-body density matrix, an infinite rank self-adjoint operator which is a compact perturbation of the negative spectral projector of the free Dirac operator (the Dirac sea). We study the minimization of the reduced BDF energy under a charge constraint. We prove the existence of minimizers for a large range of values of the charge, and any positive value of the coupling constant α\alpha. Our result covers neutral and positively charged molecules, provided that the positive charge is not large enough to create electron-positron pairs. We also prove that the density of any minimizer is an L1L^1 function and compute the effective charge of the system, recovering the usual renormalization of charge: the physical coupling constant is related to α\alpha by the formula αphysα(1+2α/(3π)logΛ)1\alpha_{\rm phys}\simeq \alpha(1+2\alpha/(3\pi)\log\Lambda)^{-1}, where Λ\Lambda is the ultraviolet cut-off. We eventually prove an estimate on the highest number of electrons which can be bound by a nucleus of charge ZZ. In the nonrelativistic limit, we obtain that this number is 2Z\leq 2Z, recovering a result of Lieb. This work is based on a series of papers by Hainzl, Lewin, Sere and Solovej on the mean-field approximation of no-photon QED.Comment: 37 pages, 1 figur

    Insektenvielfalt in der Schweiz: Bedeutung, Trends, Handlungsoptionen

    Get PDF
    Die Situation der Insekten in der Schweiz sei besorgniserregend, schreiben Forschende im ersten umfassenden Zustandsbericht «Insektenvielfalt in der Schweiz», publiziert vom Forum Biodiversität der Akademie der Naturwissenschaften Schweiz. Sie haben die verfügbaren Daten der Roten Listen, von Monitoringprogrammen und Studien analysiert. Demnach gingen Vielfalt und Grösse der Insektenbestände vor allem im Mittelland stark zurück, mittlerweile aber auch im Jura und in den Alpen. Um die teils dramatischen Entwicklungen zu stoppen, schlagen die Autorinnen und Autoren das wissenschaftlich basierte «12-Punkte-Programm Insekten» vor
    corecore