University of Iceland

About: University of Iceland is a education organization based out in Reykjavik, Suðurnes, Iceland. It is known for research contribution in the topics: Population & Genome-wide association study. The organization has 5423 authors who have published 16199 publications receiving 694762 citations. The organization is also known as: Háskóli Íslands.

Genome-wide association studies of cerebral white matter lesion burden: the CHARGE consortium.

Abstract: textObjective: White matter hyperintensities (WMHs) detectable by magnetic resonance imaging are part of the spectrum of vascular injury associated with aging of the brain and are thought to reflect ischemic damage to the small deep cerebral vessels. WMHs are associated with an increased risk of cognitive and motor dysfunction, dementia, depression, and stroke. Despite a significant heritability, few genetic loci influencing WMH burden have been identified. Methods: We performed a meta-analysis of genome-wide association studies (GWASs) for WMH burden in 9,361 stroke-free individuals of European descent from 7 community-based cohorts. Significant findings were tested for replication in 3,024 individuals from 2 additional cohorts. Results: We identified 6 novel risk-associated single nucleotide polymorphisms (SNPs) in 1 locus on chromosome 17q25 encompassing 6 known genes including WBP2, TRIM65, TRIM47, MRPL38, FBF1, and ACOX1. The most significant association was for rs3744028 (pdiscovery= 4.0 × 10-9; preplication= 1.3 × 10-7; pcombined= 4.0 × 10-15). Other SNPs in this region also reaching genome-wide significance were rs9894383 (p = 5.3 × 10-9), rs11869977 (p = 5.7 × 10-9), rs936393 (p = 6.8 × 10-9), rs3744017 (p = 7.3 × 10-9), and rs1055129 (p = 4.1 × 10-8). Variant alleles at these loci conferred a small increase in WMH burden (4-8% of the overall mean WMH burden in the sample). Interpretation: This large GWAS of WMH burden in community-based cohorts of individuals of European descent identifies a novel locus on chromosome 17. Further characterization of this locus may provide novel insights into the pathogenesis of cerebral WMH.

Understanding the Archaeological Record

Abstract: This book explores the diverse understandings of the archaeological record in both historical and contemporary perspective, while also serving as a guide to reassessing current views. Gavin Lucas argues that archaeological theory has become both too fragmented and disconnected from the particular nature of archaeological evidence. The book examines three ways of understanding the archaeological record - as historical sources, through formation theory and as material culture - then reveals ways to connect these three domains through a reconsideration of archaeological entities and archaeological practice. Ultimately, Lucas calls for a rethinking of the nature of the archaeological record and the kind of history and narratives written from it.

Abdominal Aortic Aneurysm Is Associated with a Variant in Low-Density Lipoprotein Receptor-Related Protein 1

Abstract: Abdominal aortic aneurysm (AAA) is a common cause of morbidity and mortality and has a significant heritability. We carried out a genome-wide association discovery study of 1866 patients with AAA and 5435 controls and replication of promising signals (lead SNP with a p value < 1 × 10(-5)) in 2871 additional cases and 32,687 controls and performed further follow-up in 1491 AAA and 11,060 controls. In the discovery study, nine loci demonstrated association with AAA (p < 1 × 10(-5)). In the replication sample, the lead SNP at one of these loci, rs1466535, located within intron 1 of low-density-lipoprotein receptor-related protein 1 (LRP1) demonstrated significant association (p = 0.0042). We confirmed the association of rs1466535 and AAA in our follow-up study (p = 0.035). In a combined analysis (6228 AAA and 49182 controls), rs1466535 had a consistent effect size and direction in all sample sets (combined p = 4.52 × 10(-10), odds ratio 1.15 [1.10-1.21]). No associations were seen for either rs1466535 or the 12q13.3 locus in independent association studies of coronary artery disease, blood pressure, diabetes, or hyperlipidaemia, suggesting that this locus is specific to AAA. Gene-expression studies demonstrated a trend toward increased LRP1 expression for the rs1466535 CC genotype in arterial tissues; there was a significant (p = 0.029) 1.19-fold (1.04-1.36) increase in LRP1 expression in CC homozygotes compared to TT homozygotes in aortic adventitia. Functional studies demonstrated that rs1466535 might alter a SREBP-1 binding site and influence enhancer activity at the locus. In conclusion, this study has identified a biologically plausible genetic variant associated specifically with AAA, and we suggest that this variant has a possible functional role in LRP1 expression.

Oceanic evidence for coherent fluctuations in Fennoscandian and Laurentide ice sheets on millennium timescales

Abstract: PROXY temperature records from Greenland ice cores1,2 and North Atlantic sediment cores3 have provided evidence for a high degree of climate instability during the last glacial period. Much of this variability seems to be linked with the dynamics of the Laurentide ice sheet that covered North America at this time3, which dis-charged iceberg flotillas into the North Atlantic that are now recorded in sediment cores as Heinrich events4. How (if at all) this variability was manifested on the other side of the Atlantic— in the Nordic seas and the ice sheets of northwest Europe and Scandinavia—has been unclear. Here we present sediment, micro-fossil and oxygen isotope data from a sediment core in the Norweg-ian sea, which reveal cooling events and iceberg discharges analogous to Heinrich events. We show that these climate fluctua-tions in the Norwegian Sea were in phase, or were phase-locked, with air temperatures over Greenland, suggesting that the rapid changes in heat fluxes in the North Atlantic recorded in previous records3 were felt in this high-latitude region. The iceberg dis-charges in our record seem to have come from the Fennoscandian ice sheet, implying that this and the Laurentide ice sheets fluctu-ated coherently on timescales shorter than those of Milankovitch orbital cycles.