Erna V. Ivarsdottir, Valgerður Steinthórsdóttir, Maryam S. Daneshpour, Guðmar Þorleifsson, Patrick Sulem, Hilma Hólm, Snævar Sigurðsson, Ástráður B. Hreiðarsson, Gunnar Sigurðsson, Ragnar Bjarnason, Árni V. Þórsson, Rafn Benediktsson, Guðmundur I. Eyjólfsson, Ólöf Sigurðardóttir, Ísleifur Ólafsson, Sirous Zeinali, Fereidoun Azizi, Unnur Þorsteinsdóttir, Daníel F. Guðbjartsson, Kári Stéfansson,
Tópico(s): Epigenetics and DNA Methylation
2017 - Nature Portfolio | Nature Genetics
Ágúst Guðmundsson, N. Óskarsson, Karl Grönvold, Kristján Sæmundsson, Oddur Sigurðsson, Ragnar Stefánsson, Sigurður R. Gíslason, Páll Einarsson, Bryndís Brandsdóttir, Guðrún Larsen, Haukur Jóhannesson, T. Thórdarson,
Tópico(s): earthquake and tectonic studies
1992 - Springer Science+Business Media | Bulletin of Volcanology
Alexander Rashkovskii, Ragnar Sigurðsson,
We study properties of a Green function G A with singularities along a complex subspace A of a complex manifold X. It is defined as the largest negative plurisubharmonic function u satisfying locally u≤ log |ψ|+C, where ψ=(ψ 1 ,…,ψ m ), ψ 1 ,…,ψ m are local generators for the ideal sheaf ℐ A of A, and C is a constant depending on the function u and the generators. A motivation for this study is to estimate global bounded functions from the sheaf ℐ A and thus proving a "Schwarz lemma" for ℐ A .
Tópico(s): Geometric Analysis and Curvature Flows
2005 - World Scientific | International Journal of Mathematics
Finnur Lárusson, Ragnar Sigurðsson,
We establish disc formulas for the Siciak–Zahariuta extremal function of an arbitrary open subset of complex affine space. This function is also known as the pluricomplex Green function with logarithmic growth or a logarithmic pole at infinity. We e
Tópico(s): Analytic and geometric function theory
2005 - Polish Academy of Sciences | Annales Polonici Mathematici
Finnur Lárusson, Ragnar Sigurðsson,
We show that a disc functional on a complex manifold has a plurisubharmonic envelope if all its pullbacks by holomorphic submersions from domains of holomorphy in affine space do and it is locally bounded above and upper semicontinuous in a certain weak sense.For naturally defined classes of disc functionals on manifolds, this result reduces a property somewhat stronger than having a plurisubharmonic envelope to the affine case.The proof uses a recent Stein neighbourhood construction of Rosay, who ...
Tópico(s): Advanced Algebra and Geometry
2003 - De Gruyter | Journal für die reine und angewandte Mathematik (Crelles Journal)
Ragnar Sigurðsson, Finnur Lárusson,
Tópico(s): Algebraic and Geometric Analysis
1998 - De Gruyter | Journal für die reine und angewandte Mathematik (Crelles Journal)
Sigmundur Gudmundsson, Ragnar Sigurðsson,
Tópico(s): Analytic and geometric function theory
1993 - Springer Science+Business Media | Potential Analysis
Tópico(s): advanced mathematical theories
1991 - Mittag-Leffler Institute | Arkiv för matematik
Etude de la croissance des fonctions analytiques dans C x d'ordre et de type finis. Fonctions generales d'ordre ρ. Transformations de Fourier-Laplace des hyperfonctions a support compact. Transformations de Fourier-Laplace des distributions a support compact
Tópico(s): Holomorphic and Operator Theory
1986 - Aarhus University Library | MATHEMATICA SCANDINAVICA
Finnur Lárusson, Ragnar Sigurðsson,
We introduce a new type of pluricomplex Green function which has a logarithmic pole along a complex subspace A of a complex manifold X.It is the largest negative plurisubharmonic function on X whose Lelong number is at least the Lelong number of log max{|f 1 |, ..., |f m |}, where f 1 , ..., f m are local generators for the ideal sheaf of A. The pluricomplex Green function with a single logarithmic pole or a finite number of weighted poles is a very special case of our construction.We give several equivalent definitions ...
Tópico(s): Analytic and geometric function theory
1999 - Indiana University | Indiana University Mathematics Journal
Finnur Lárusson, Ragnar Sigurðsson,
We prove two disc formulas for the Siciak–Zahariuta extremal function of an arbitrary open subset of complex affine space. We use these formulas to characterize the polynomial hull of an arbitrary compact subset of complex affine space in terms of analytic discs. Similar results in previous work of ours required the subsets to be connected.
Tópico(s): Analytic and geometric function theory
2009 - Springer Nature | Mathematische Annalen
Finnur Lárusson, Patrice Lassère, Ragnar Sigurðsson,
Let X be a convex domain in ℂⁿ and let E be a convex subset of X. The relative extremal function $u_{E,X}$ for E in X is the supremum of the class of plurisubharmonic functions v ≤ 0 on X with v ≤ -1 on E. We show that if E is either open or compact, then
Tópico(s): Meromorphic and Entire Functions
1998 - Polish Academy of Sciences | Annales Polonici Mathematici
Thorunn A. Olafsdottir, Kristbjörg Bjarnadóttir, Gudmundur L. Norddahl, Gísli H. Halldórsson, Páll Melsted, Kristbjörg Gunnarsdóttir, Erna V. Ivarsdottir, Þórhildur Ólafsdóttir, Asgeir Ö. Arnthórsson, Fannar Theódórs, Elías Eyþórsson, Daði Helgason, Hannes P. Eggertsson, Gísli Másson, Sólveig Bjarnadóttir, Saedís Saevarsdóttir, Hrafnhildur L. Runolfsdottir, Ísleifur Ólafsson, Jona Saemundsdottir, Martin I. Sigurðsson, Ragnar Freyr Ingvarsson, Runólfur Pálsson, Guðmundur Þorgeirsson, Bjarni V. Halldórsson, Hilma Hólm, Már Kristjánsson, Patrick Sulem, Unnur Þorsteinsdóttir, Ingileif Jónsdóttir, Daníel F. Guðbjartsson, Kāri Stefánsson,
Abstract Memory T-cell responses following SARS-CoV-2 infection have been extensively investigated but many studies have been small with a limited range of disease severity. Here we analyze SARS-CoV-2 reactive T-cell responses in 768 convalescent SARS-CoV-2-infected (cases) and 500 uninfected (controls) Icelanders. The T-cell responses are stable three to eight months after SARS-CoV-2 infection, irrespective of disease severity and even those with the mildest symptoms induce broad and persistent T- ...
Tópico(s): Immune responses and vaccinations
2022 - Nature Portfolio | Communications Biology
Kristján Norland, Garðar Sveinbjörnsson, Rósa B. Þórólfsdóttir, Olafur B. Davidsson, Vinicius Tragante, Sridharan Rajamani, Anna Helgadóttir, Sólveig Grétarsdóttir, Jessica van Setten, Folkert W. Asselbergs, Jon T. Sverrisson, Sigurdur S. Stephensen, Gylfi Óskarsson, Engilbert Sigurðsson, Karl Andersen, Ragnar Daníelsen, Guðmundur Þorgeirsson, Unnur Þorsteinsdóttir, Davíð O. Arnar, Patrick Sulem, Hilma Hólm, Daníel F. Guðbjartsson, Kári Stéfansson,
Abstract Features of the QRS complex of the electrocardiogram, reflecting ventricular depolarisation, associate with various physiologic functions and several pathologic conditions. We test 32.5 million variants for association with ten measures of the QRS complex in 12 leads, using 405,732 electrocardiograms from 81,192 Icelanders. We identify 190 associations at 130 loci, the majority of which have not been reported before, including associations with 21 rare or low-frequency coding variants. ...
Tópico(s): Cardiac electrophysiology and arrhythmias
2019 - Nature Portfolio | Nature Communications
Garðar Sveinbjörnsson, Eva F. Olafsdottir, Rósa B. Þórólfsdóttir, Olafur B. Davidsson, Anna Helgadóttir, Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, Eyþór Björnsson, Brynjar Ö. Jensson, Gudny A. Arnadottir, Hallfríður Kristinsdóttir, Sigurdur S. Stephensen, Gylfi Óskarsson, Tómas Guðbjartsson, Engilbert Sigurðsson, Karl Andersen, Ragnar Daníelsen, Davíð O. Arnar, Ingileif Jónsdóttir, Unnur Þorsteinsdóttir, Patrick Sulem, Guðmundur Þorgeirsson, Daníel F. Guðbjartsson, Hilma Hólm, Kāri Stefánsson,
Dilated cardiomyopathy (DCM) is an important cause of heart failure. Variants in >50 genes have been reported to cause DCM, but causative variants have been found in less than half of familial cases. Variants causing DCM in Iceland have not been reported before.We performed a genome-wide association study on DCM based on whole genome sequencing. We tested the association of 32.5 million sequence variants in 424 cases and 337 689 population controls in Iceland.We identified 2 DCM variants in established ...
Tópico(s): RNA and protein synthesis mechanisms
2018 - Wolters Kluwer | Circulation Genomic and Precision Medicine
Rajesh Rupakhety, S. U. Sigurdsson, Apostolos Papageorgiou, Ragnar Sigbjörnsson,
Tópico(s): Structural Response to Dynamic Loads
2011 - Springer Science+Business Media | Bulletin of Earthquake Engineering
Aimée M. Deaton, Patrick Sulem, Paul Nioi, Stefania Benónísdóttir, Lucas D. Ward, Olafur B. Davidsson, Socheata Lao, Anna Helgadóttir, Fan Fan, Brynjar Ö. Jensson, Gudmundur L. Norddahl, Áslaug Jónasdóttir, Aðalbjörg Jónasdóttir, Ásgeir Sigurðsson, Ragnar P. Kristjansson, Ásmundur Oddsson, Gudny A. Arnadottir, Hákon Jónsson, Ísleifur Ólafsson, Guðmundur I. Eyjólfsson, Ólöf Sigurðardóttir, Einar S. Björnsson, Sigurður Ólafsson, Þóra Steingrímsdóttir, Þórunn Rafnar, Guðmundur Þorgeirsson, Gísli Másson, Guðmar Þorleifsson, Daníel F. Guðbjartsson, Hilma Hólm, Unnur Þorsteinsdóttir, Kári Stéfansson,
Searching for novel sequence variants associated with cholesterol levels is of particular interest due to the causative role of non-HDL cholesterol levels in cardiovascular disease. Through whole-genome sequencing of 15,220 Icelanders and imputation of the variants identified, we discovered a rare missense variant in NR1H4 (R436H) associating with lower levels of total cholesterol (effect = -0.47 standard deviations or -0.55 mmol L-1, p = 4.21 × 10-10, N = 150,211). Importantly, NR1H4 R436H also associates ...
Tópico(s): Metabolism and Genetic Disorders
2018 - Nature Portfolio | Communications Biology
Evgeny A. Poletsky, Ragnar Sigurðsson,
In this paper we solve the Dirichlet problems for different classes of plurisubharmonic functions on compact sets in $${\mathbb C^n}$$ including continuous, pluriharmonic and maximal functions.
Tópico(s): Holomorphic and Operator Theory
2011 - Springer Science+Business Media | Mathematische Zeitschrift
Sigurður Ragnarsson, Martin I. Sigurðsson, Ragnar Daníelsen, Þórarinn Arnórsson, Tómas Guðbjartsson,
Mitral valve replacement (MVR) is the second most common valvular replacement procedure after aortic valve replacement (AVR). Studies on the outcome of MVR in Iceland have been missing. We therefore studied short and long-term results following MVR in Iceland,A retrospective nationwide study on 64 patients (mean age 59 years, 63% males) that underwent 66 MVR procedures in Iceland between 1990-2010. Clinical data was retrieved from patient charts and overall survival estimated. The mean follow-up was ...
Tópico(s): Cardiac Structural Anomalies and Repair
2012 - The Icelandic Medical Association | Læknablaðið
Jón Magnússon, Alexander Rashkovskii, Ragnar Sigurðsson, Pascal J. Thomas,
Let Ω be a bounded hyperconvex domain in ℂ n , 0 ∈ Ω, and S ε a family of N poles in Ω, all tending to 0 as ε tends to 0. To each S ε we associate its vanishing ideal [Formula: see text] and pluricomplex Green function [Formula: see text]. Suppose that, as ε tends to 0, [Formula: see text] converges to [Formula: see text] (local uniform convergence), and that (G ε ) ε converges to G, locally uniformly away from 0; then [Formula: see text]. If the Hilbert–Samuel multiplicity of [Formula: see text] is strictly ...
Tópico(s): Algebraic Geometry and Number Theory
2012 - World Scientific | International Journal of Mathematics
Benedikt Steinar Magnússon, Ragnar Sigurðsson,
We prove a disc formula for the weighted Siciak–Zahariuta extremal function $V_{X,q}$ for an upper semicontinuous function $q$ on an open connected subset $X$ in $\mathbb C^n$. This function is also known as the weighted Green function with log
Tópico(s): Holomorphic and Operator Theory
2007 - Polish Academy of Sciences | Annales Polonici Mathematici
Finnur Lárusson, Ragnar Sigurðsson,
We use our disc formula for the Siciak–Zahariuta extremal function to characterize the polynomial hull of a connected compact subset of complex affine space in terms of analytic discs.
Tópico(s): Meromorphic and Entire Functions
2007 - Polish Academy of Sciences | Annales Polonici Mathematici
Lars Hörmander, Ragnar Sigurðsson,
Tópico(s): Advanced Harmonic Analysis Research
1998 - Springer Science+Business Media | Journal of Geometric Analysis
Guðrún A. Jónsdóttir, Guðmundur Einarsson, Guðmar Þorleifsson, Sigurður H. Magnússon, Arni F. Gunnarsson, Michael L. Frigge, Rósa S. Gísladóttir, Unnur Unnsteinsdóttir, Bjarni Gunnarsson, G. Bragi Walters, Valgerður Steinthórsdóttir, Anna Helgadóttir, Ingileif Jónsdóttir, Þorsteinn Gíslason, Haraldur Þorsteinsson, Engilbert Sigurðsson, Magnús Haraldsson, Engilbert Sigurðsson, Ragnar Bjarnason, Ísleifur Ólafsson, Guðmundur Þorgeirsson, Patrick Sulem, Hilma Hólm, Unnur Þorsteinsdóttir, Daníel F. Guðbjartsson, Gyða Björnsdóttir, Thorgeir E. Thorgeirsson, Hreinn Stefánsson, Hreinn Stefánsson,
We generated two polygenic scores, one capturing verbal and the other spatial aspects of cognitive ability, using UK Biobank data and studied their effects on various diseases and other traits in the Icelandic population. The score tagging spatial ability associated with higher body mass index (β = 0.032, p = 3.2 × 10 −13 ), but lower risk of schizophrenia (OR = 0.82, p = 8.8 × 10 −9 ) and other mental disorders. Furthermore, it associated with less openness, a personality trait reflecting curiosity and creativity (β = − ...
Tópico(s): Epigenetics and DNA Methylation
2021 - Elsevier BV | Intelligence
Þorsteinn Björnsson, Rósa B. Þórólfsdóttir, Garðar Sveinbjörnsson, Patrick Sulem, Gudmundur L. Norddahl, Anna Helgadóttir, Sólveig Grétarsdóttir, Audur Magnusdottir, Ragnar Daníelsen, Engilbert Sigurðsson, Berglind Aðalsteinsdóttir, Sverrir I. Gunnarsson, Ingileif Jónsdóttir, Davíð O. Arnar, Hróðmar Helgason, Tómas Guðbjartsson, Daníel F. Guðbjartsson, Unnur Þorsteinsdóttir, Hilma Hólm, Kāri Stefánsson,
Coarctation of the aorta (CoA) accounts for 4-8% of congenital heart defects (CHDs) and confers substantial morbidity despite treatment. It is increasingly recognized as a highly heritable condition. The aim of the study was to search for sequence variants that affect the risk of CoA.We performed a genome-wide association study of CoA among Icelanders (120 cases and 355 166 controls) based on imputed variants identified through whole-genome sequencing. We found association with a rare (frequency = 0.34%) ...
Tópico(s): Cardiac Valve Diseases and Treatments
2018 - Oxford University Press | European Heart Journal
Eyþór Björnsson, Guðmundur Þorgeirsson, Anna Helgadóttir, Guðmar Þorleifsson, Garðar Sveinbjörnsson, Snædís Kristmundsdóttir, Hákon Jónsson, Aðalbjörg Jónasdóttir, Áslaug Jónasdóttir, Ásgeir Sigurðsson, Þórarinn Guðnason, Ísleifur Ólafsson, Engilbert Sigurðsson, Ólöf Sigurðardóttir, Brynjar Viðarsson, Magnús Baldvinsson, Ragnar Bjarnason, Ragnar Daníelsen, Stefán E. Matthíasson, Bjorn Thorarinsson, Sólveig Grétarsdóttir, Valgerður Steinthórsdóttir, Bjarni V. Halldórsson, Karl Andersen, Davíð O. Arnar, Ingileif Jónsdóttir, Daníel F. Guðbjartsson, Hilma Hólm, Unnur Þorsteinsdóttir, Patrick Sulem, Kāri Stefánsson,
Objective: Familial hypercholesterolemia (FH) is traditionally defined as a monogenic disease characterized by severely elevated LDL-C (low-density lipoprotein cholesterol) levels. In practice, FH is commonly a clinical diagnosis without confirmation of a causative mutation. In this study, we sought to characterize and compare monogenic and clinically defined FH in a large sample of Icelanders. Approach and Results: We whole-genome sequenced 49 962 Icelanders and imputed the identified variants into ...
Tópico(s): Cancer, Lipids, and Metabolism
2021 - Lippincott Williams & Wilkins | Arteriosclerosis Thrombosis and Vascular Biology
Elías Eyþórsson, Hrafnhildur L. Runolfsdottir, Ragnar Freyr Ingvarsson, Martin I. Sigurðsson, Runólfur Pálsson,
Tópico(s): COVID-19 Pandemic Impacts
2022 - American Medical Association | JAMA Network Open
Hákon Guðbjartsson, G. Georgsson, Sigurjón A. Guðjónsson, Ragnar þór Valdimarsson, Jóhann H. Sigurðsson, Sigmar K. Stefánsson, Gísli Másson, Gísli Magnússon, Vilmundur Pálmason, Kári Stéfansson,
Our aim was to create a general-purpose relational data format and analysis tools to provide an efficient and coherent framework for working with large volumes of DNA sequence data.For this purpose we developed the GORpipe software system. It is based on a genomic ordered architecture and uses a declarative query language that combines features from SQL and shell pipe syntax in a novel manner. The system can for instance be used to annotate sequence variants, find genomic spatial overlap between ...
Tópico(s): Bioinformatics and Genomic Networks
2016 - Oxford University Press | Bioinformatics
S. U. Sigurdsson, Rajesh Rupakhety, Ragnar Sigbjörnsson,
Tópico(s): Structural Health Monitoring Techniques
2011 - Elsevier BV | Soil Dynamics and Earthquake Engineering
Mats R. Andersson, Jan Boman, Christer O. Kiselman, Pavel Kurasov, Ragnar Sigurðsson,
This book is dedicated to the memory of Mikael Passare, an outstanding Swedish mathematician who devoted his life to developing the theory of analytic functions in several complex variables and explor
2017 - Springer Nature | Trends in mathematics