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.

Single-tissue and cross-tissue heritability of gene expression via identity-by-descent in related or unrelated individuals.

Abstract: Family studies of individual tissues have shown that gene expression traits are genetically heritable. Here, we investigate cis and trans components of heritability both within and across tissues by applying variance-components methods to 722 Icelanders from family cohorts, using identity-by-descent (IBD) estimates from long-range phased genome-wide SNP data and gene expression measurements for ∼19,000 genes in blood and adipose tissue. We estimate the proportion of gene expression heritability attributable to cis regulation as 37% in blood and 24% in adipose tissue. Our results indicate that the correlation in gene expression measurements across these tissues is primarily due to heritability at cis loci, whereas there is little sharing of trans regulation across tissues. One implication of this finding is that heritability in tissues composed of heterogeneous cell types is expected to be more dominated by cis regulation than in tissues composed of more homogeneous cell types, consistent with our blood versus adipose results as well as results of previous studies in lymphoblastoid cell lines. Finally, we obtained similar estimates of the cis components of heritability using IBD between unrelated individuals, indicating that transgenerational epigenetic inheritance does not contribute substantially to the “missing heritability” of gene expression in these tissue types.

Retinal oxygen saturation is altered in diabetic retinopathy.

Abstract: Aim Retinal oxygen metabolism is thought to be affected in diabetic retinopathy. The aim of this study was to test whether retinal vessel oxygen saturation is different in patients with diabetic retinopathy from that in healthy controls. Methods The retinal oximeter is based on a fundus camera. It estimates retinal vessel oxygen saturation from light absorbance at 586 nm and 605 nm. Retinal vessel oxygen saturation was measured in one major temporal retinal arteriole and venule in healthy volunteers and in patients with diabetic retinopathy. Results Oxygen saturation in the retinal arterioles of healthy volunteers was 93±4% and 58±6% in venules (mean±SD, n=31). The corresponding values for all diabetic patients (n=20) were 101±5% and 68±7%. The difference between healthy volunteers and diabetic patients was statistically significant (p Conclusion Retinal vessel oxygen saturation is higher in patients with diabetic retinopathy than in healthy controls. Possible explanations include shunting of blood through preferential channels, bypassing non-perfused capillaries in the capillary network. Parts of the retinal tissue may be hypoxic while blood in larger vessels has high oxygen saturation.

Coping with bullying in the workplace: the effect of gender, age and type of bullying

Abstract: A study of bullying, victimisation and the coping strategies employed to tackle it is presented in the first study of bullying in the workplace conducted in Iceland. Participants were 398 members of a union of store and office workers and members of a national organisation of bank-employees. A factor analysis of bullying items identified two factors: general bullying and work-related bullying. Males score higher on both factors, but when asked directly if they have been bullied or not, no significant gender difference appears. A measure of coping strategies when faced with bullying is presented. A factor analysis and multidimensional scaling of these strategies identified four clusters: assertive response, seek help, avoidance and do nothing. These can be arranged on a passive vs. active dimension, which may reflect the severity or duration of the bullying situation. Multiple regressions indicate that males seek help less and use avoidance less than females, and males are more likely to use assertive stra...

KLB is associated with alcohol drinking, and its gene product β-Klotho is necessary for FGF21 regulation of alcohol preference

Abstract: Excessive alcohol consumption is a major public health problem worldwide. Although drinking habits are known to be inherited, few genes have been identified that are robustly linked to alcohol drinking. We conducted a genome-wide association metaanalysis and replication study among >105,000 individuals of European ancestry and identified β-Klotho (KLB) as a locus associated with alcohol consumption (rs11940694; P = 9.2 × 10−12). β-Klotho is an obligate coreceptor for the hormone FGF21, which is secreted from the liver and implicated in macronutrient preference in humans. We show that brain-specific β-Klotho KO mice have an increased alcohol preference and that FGF21 inhibits alcohol drinking by acting on the brain. These data suggest that a liver–brain endocrine axis may play an important role in the regulation of alcohol drinking behavior and provide a unique pharmacologic target for reducing alcohol consumption.

Characterization of Eyjafjallajokull volcanic ash particles and a protocol for rapid risk assessment

Abstract: On April 14, 2010, when meltwaters from the Eyjafjallajokull glacier mixed with hot magma, an explosive eruption sent unusually fine-grained ash into the jet stream. It quickly dispersed over Europe. Previous airplane encounters with ash resulted in sandblasted windows and particles melted inside jet engines, causing them to fail. Therefore, air traffic was grounded for several days. Concerns also arose about health risks from fallout, because ash can transport acids as well as toxic compounds, such as fluoride, aluminum, and arsenic. Studies on ash are usually made on material collected far from the source, where it could have mixed with other atmospheric particles, or after exposure to water as rain or fog, which would alter surface composition. For this study, a unique set of dry ash samples was collected immediately after the explosive event and compared with fresh ash from a later, more typical eruption. Using nanotechniques, custom-designed for studying natural materials, we explored the physical and chemical nature of the ash to determine if fears about health and safety were justified and we developed a protocol that will serve for assessing risks during a future event. On single particles, we identified the composition of nanometer scale salt coatings and measured the mass of adsorbed salts with picogram resolution. The particles of explosive ash that reached Europe in the jet stream were especially sharp and abrasive over their entire size range, from submillimeter to tens of nanometers. Edges remained sharp even after a couple of weeks of abrasion in stirred water suspensions.