336 research outputs found

    Developing a transnational electricity infrastructure offshore: interdependence between technical and regulatory solutions

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    This paper aims at identifying the options for designing an offshore electricity grid and the legal instruments to create such a grid. It will make a first attempt at presenting the technical and legal considerations which coastal states, EU and national legislators and policy makers should take into account in the coming years when planning and weighing their grid design options. By contrast to the onshore system where the current grid is the result of many decades of local, regional, national and international developments, the situation offshore is different in the sense that currently there is more or less no grid. Moreover, the legal basis for developing such a grid is different offshore than onshore. Therefore designing a system which looks beyond national interests and concepts represents a major challenge. We will discuss whether such a new development as the construction of an offshore electricity grid should be a matter of national policy or should a multilateral or international approach be preferred

    Descent of Equivalences and Character Bijections

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    Categorical equivalences between block algebras of finite groups—such as Morita and derived equivalences—are well known to induce character bijections which commute with the Galois groups of field extensions. This is the motivation for attempting to realise known Morita and derived equivalences over non-splitting fields. This article presents various results on the theme of descent to appropriate subfields and subrings. We start with the observation that perfect isometries induced by a virtual Morita equivalence induce isomorphisms of centres in non-split situations and explain connections with Navarro’s generalisation of the Alperin–McKay conjecture. We show that Rouquier’s splendid Rickard complex for blocks with cyclic defect groups descends to the non-split case. We also prove a descent theorem for Morita equivalences with endopermutation source

    The geometry of the limit of N=2 minimal models

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    We consider the limit of two-dimensional N=(2,2) superconformal minimal models when the central charge approaches c=3. Starting from a geometric description as non-linear sigma models, we show that one can obtain two different limit theories. One is the free theory of two bosons and two fermions, the other one is a continuous orbifold thereof. We substantiate this claim by detailed conformal field theory computations.Comment: 35 pages, 3 figures; v2 minor corrections, version to be published in J. Phys.

    Selenium Status in Paediatric Patients with Neurodevelopmental Diseases

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    Neurodevelopmental diseases are often associated with other comorbidities, especially inflammatory processes. The disease may affect the trace element (TE) status, which in turn may affect disease severity and progression. Selenium (Se) is an essential TE required for the biosynthesis of selenoproteins including the transporter selenoprotein P (SELENOP) and extracellular glutathione peroxidase (GPX3). SELENOP deficiency in transgenic mice resulted in a Se status-dependent phenotype characterized by impaired growth and disturbed neuronal development, with epileptic seizures on a Se-deficient diet. Therefore, we hypothesized that Se and SELENOP deficiencies may be prevalent in paediatric patients with a neurodevelopmental disease. In an exploratory cross-sectional study, serum samples from children with neurodevelopmental diseases (n = 147) were analysed for total serum Se, copper (Cu), and zinc (Zn) concentrations as well as for the TE biomarkers SELENOP, ceruloplasmin (CP), and GPX3 activity. Children with epilepsy displayed elevated Cu and Zn concentrations but no dysregulation of serum Se status. Significantly reduced SELENOP concentrations were found in association with intellectual disability (mean +/- SD (standard deviation); 3.9 +/- 0.9 mg/L vs. 4.4 +/- 1.2 mg/L, p = 0.015). A particularly low GPX3 activity (mean +/- SD; 172.4 +/- 36.5 vs. 192.6 +/- 46.8 U/L, p = 0.012) was observed in phacomatoses. Autoantibodies to SELENOP, known to impair Se transport, were not detected in any of the children. In conclusion, there was no general association between Se deficiency and epilepsy in this observational analysis, which does not exclude its relevance to individual cases. Sufficiently high SELENOP concentrations seem to be of relevance to the support of normal mental development. Decreased GPX3 activity in phacomatoses may be relevant to the characteristic skin lesions and merits further analysis. Longitudinal studies are needed to determine whether the observed differences are relevant to disease progression and whether correcting a diagnosed TE deficiency may confer health benefits to affected children
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