State-of-the-art research : reflections on a concerted Nordic-Baltic nuclear energy effort

Quite a few hold the view that nuclear energy will have its renaissance in the not too distant future. Technology is, however, a necessary, but not sufficient condition. The needed prerequisites represent a complex issue. With increasing energy demand and depletion of non-renewable energy resources, nuclear will have to prove its role in an increasing energy mix, globally, regionally and often also nationally. Based on its history, experience with coordinated interplay in electricity production from a variety of energy sources, and science engagements, we argue for a future Nordic/Baltic SHOW CASE: A nuclear weapons free and proliferation safe nuclear energy supplier in the region, with a concerted role in competence building and in international ventures, and with focus on operation, safety economy and societal aspects

Loss-of-Function Variants in Cytoskeletal Genes Are Associated with Early-Onset Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and it is associated with an increased risk of heart failure, stroke, dementia, and death. Recently, titin-truncating variants (TTNtv), which are predominantly associated with dilated cardiomyopathy (DCM), were associated with early-onset AF. Furthermore, genome-wide association studies (GWAS) associated AF with other structural genes. In this study, we investigated whether early-onset AF was associated with loss-of-function variants in DCM-associated genes encoding cytoskeletal proteins. Using targeted sequencing, we examined a cohort of 527 Scandinavian individuals with early-onset AF and a control group of individuals free of AF (n = 383). The patients had onset of AF before 50 years of age, normal echocardiogram, and no other cardiovascular disease at onset of AF. We identified six individuals with rare loss-of-function variants in three different genes (dystrophin (DMD), actin-associated LIM protein (PDLIM3), and fukutin (FKTN)), of which two variants were novel. Loss-of-function variants in cytoskeletal genes were significantly associated with early-onset AF when patients were compared with controls (p = 0.044). Using publicly available GWAS data, we performed genetic correlation analyses between AF and 13 other traits, e.g., showing genetic correlation between AF and non-ischemic cardiomyopathy (p = 0.0003). Our data suggest that rare loss-of-function variants in cytoskeletal genes previously associated with DCM may have a role in early-onset AF, perhaps through the development of an atrial cardiomyopathy

Multi-ethnic genome-wide association study for atrial fibrillation

Atrial fibrillation (AF) affects more than 33 million individuals worldwide and has a complex heritability. We conducted the largest meta-analysis of genome-wide association studies (GWAS) for AF to date, consisting of more than half a million individuals, including 65,446 with AF. In total, we identified 97 loci significantly associated with AF, including 67 that were novel in a combined-ancestry analysis, and 3 that were novel in a European-specific analysis. We sought to identify AF-associated genes at the GWAS loci by performing RNA-sequencing and expression quantitative trait locus analyses in 101 left atrial samples, the most relevant tissue for AF. We also performed transcriptome-wide analyses that identified 57 AF-associated genes, 42 of which overlap with GWAS loci. The identified loci implicate genes enriched within cardiac developmental, electrophysiological, contractile and structural pathways. These results extend our understanding of the biological pathways underlying AF and may facilitate the development of therapeutics for AF

A Nonlinear Differential Equation Solver With Potential Application to Pelton Turbines

The focus in this thesis is the development and implementation of a new method for solving nonlinear differential equations on a grid. The method’s novelty lies in the way it represents continuously distributed variables by discrete information stored in a grid. The grid contains information about both the values and the values of the derivatives of the unknown functions at the grid points in the computational domain. With this method the derivatives are thus explicitly defined at each grid point rather than, as in conventional numerical schemes, implicitly given by the function values at the surrounding grid points. By using piecewise polynomial interpolation, functions can be represented with an arbitrary order of continuity over the entire computational domain. A mathematical framework is defined and the details of the polynomial interpolation is discussed, leading to the definition of particular sets of basis function which have especially favorable numerical properties for use with the current method. It is shown how this method is used to formulate sets of differential equations as algebraic equations. With special focus on the Navier-Stokes equations. A solution algorithm is developed for parallel computation on graphics processor units using C++ and OpenCL. Tests are performed on low cost hardware, and the imple- mentation is developed to meet constraints in memory capacity and processing speed. The algorithm is a residual-minimizing type and is based on the finite element method. Test cases in 1D, 2D and 3D are numerically solved using the developed code. Two conference presentations are based on the method developed in this thesis, showing ap- plication to simulation of a rising bubble under gravity in three dimensions and a fluid flow in a Pelton turbine cup, also in three dimensions