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.

Plate boundaries, rifts and transforms in Iceland

Abstract: The Iceland hotspot has a pronounced effect on the appearance and structure of the plate boundary between the North America and Eurasia Plates that crosses the island. The thick crust produced by the excess magmatism of the hotspot leads to a wider and more complicated plate boundary deformation zone than is observed along normal oceanic plate boundaries. Furthermore, the relative movement of the boundary with re- spect to the roots of the hotspot leads to unstable boundaries and rift jumps, when crustal blocks or microplates are transferred from one major plate to the other. The plate boundary zone can be divided into segments that are physiographically relatively homogeneous and possess distinct tectonic characteristics. The segments are more or less oblique to the relative spreading direction of the two major plates. The divergent componentof the movements is taken up by diking and normal faulting and is usually concentrated in the fissure swarms of the volcanic systems. The transcurrent component of the movements is often accommodated by strike-slip faulting on faults that are transverse to the plate boundary segment, so-called bookshelf faults, witnessing to the tran- sient nature of the segments. In highly oblique segments, such as the Reykjanes Peninsula Rift and the Grimsey Oblique Rift, both types of active structures occur superimposed on each other. In the South Iceland Seismic Zone, that is almost parallel to the local spreading direction, the bookshelf faults dominate the structure, pro- ducing earthquakes as large as magnitude 7. More mature transform zones, such as the Husavik-Flatey faults, have developed strike-slip faults that are sub-parallel to the plate movements. The activity on this transform zone, however, appears to be declining because of transfer of movement over to the Grimsey zone. This is supported by the lack of Holocene volcanism along the Eyjafjarðarall Rift that connects the transform to the Kolbeinsey Ridge plate boundary off shore. A ridge-jump appears to be in progress in South Iceland, where rifting is occurring in two sub-parallel rift zones, the very active Eastern Volcanic Zone and the less active Western Volcanic Zone. The block between them is seismically and volcanically inert and may be defined as a microplate, the Hreppar Microplate. It is rotating in response to the southward propagation of the Eastern Volcanic Zone and corresponding recess of the Western Volcanic Zone. Poles of relative rotation with respect to the North America and Eurasia Plates are suggested near 65.2 ◦ N, 20.1 ◦ W, and 62.8 ◦ N, 21.3 ◦ W, respectively.

Pharmaceutical applications of cyclodextrins: effects on drug permeation through biological membranes

Abstract: Objectives Cyclodextrins are useful solubilizing excipients that have gained currency in the formulator's armamentarium based on their ability to temporarily camouflage undesirable physicochemical properties. In this context cyclodextrins can increase oral bioavailability, stabilize compounds to chemical and enzymatic degradation and can affect permeability through biological membranes under certain circumstances. This latter property is examined herein as a function of the published literature as well as work completed in our laboratories. Key findings Cyclodextrins can increase the uptake of drugs through biological barriers if the limiting barrier component is the unstirred water layer (UWL) that exists between the membrane and bulk water. This means that cyclodextrins are most useful when they interact with lipophiles in systems where such an UWL is present and contributes significantly to the barrier properties of the membrane. Furthermore, these principles are used to direct the optimal formulation of drugs in cyclodextrins. A second related critical success factor in the formulation of cyclodextrin-based drug product is an understanding of the kinetics and thermodynamics of complexation and the need to optimize the cyclodextrin amount and drug-to-cyclodextrin ratios. Drug formulations, especially those targeting compartments associated with limited dissolution (i.e. the eye, subcutaneous space, etc.), should be carefully designed such that the thermodynamic activity of the drug in the formulation is optimal meaning that there is sufficient cyclodextrin to solubilize the drug but not more than that. Increasing the cyclodextrin concentration decreases the formulation ‘push’ and may reduce the bioavailability of the system. Conclusions A mechanism-based understanding of cyclodextrin complexation is essential for the appropriate formulation of contemporary drug candidates.

Large-Scale Gene-Centric Analysis Identifies Novel Variants for Coronary Artery Disease

Abstract: Coronary artery disease (CAD) has a significant genetic contribution that is incompletely characterized. To complement genome-wide association (GWA) studies, we conducted a large and systematic candidate gene study of CAD susceptibility, including analysis of many uncommon and functional variants. We examined 49,094 genetic variants in ~2,100 genes of cardiovascular relevance, using a customised gene array in 15,596 CAD cases and 34,992 controls (11,202 cases and 30,733 controls of European descent; 4,394 cases and 4,259 controls of South Asian origin). We attempted to replicate putative novel associations in an additional 17,121 CAD cases and 40,473 controls. Potential mechanisms through which the novel variants could affect CAD risk were explored through association tests with vascular risk factors and gene expression. We confirmed associations of several previously known CAD susceptibility loci (eg, 9p21.3:p<10; LPA:p<10; 1p13.3:p<10) as well as three recently discovered loci (COL4A1/COL4A2, ZC3HC1, CYP17A1:p<5×10). However, we found essentially null results for most previously suggested CAD candidate genes. In our replication study of 24 promising common variants, we identified novel associations of variants in or near LIPA, IL5, TRIB1, and ABCG5/ABCG8, with per-allele odds ratios for CAD risk with each of the novel variants ranging from 1.06-1.09. Associations with variants at LIPA, TRIB1, and ABCG5/ABCG8 were supported by gene expression data or effects on lipid levels. Apart from the previously reported variants in LPA, none of the other ~4,500 low frequency and functional variants showed a strong effect. Associations in South Asians did not differ appreciably from those in Europeans, except for 9p21.3 (per-allele odds ratio: 1.14 versus 1.27 respectively; P for heterogeneity = 0.003). This large-scale gene-centric analysis has identified several novel genes for CAD that relate to diverse biochemical and cellular functions and clarified the literature with regard to many previously suggested genes. © 2011 Butterworth et al.

Profile and competences for the European dentist.

Abstract: This paper presents the profile and competences for the European Dentist as approved by the General Assembly of the Association for Dental Education in Europe at its annual meeting held in Cardiff in September 2004. A task-force drafted the document, which was then sent to all European Dental Schools. Reactions received were used to amend the document. European dental schools are expected to adhere to the profile and the 17 major competences but the supporting competences may vary in detail between schools. The document will be reviewed in 5 years time. This paper will be disseminated to ministries of health, national dental associations and dental specialty associations or societies in Europe and these organisations will be asked to offer their comments. This information will be used in the reviewing process to be started in 2007. It is hoped that the availability of this document will assist dental schools in Europe to further harmonize and improve the quality of their curricula.

The Strengths and Difficulties Questionnaire in the Nordic countries

Abstract: Background: The Strengths and Difficulties Questionnaire (SDQ) has been translated into the different Nordic languages between 1996 and 2003. During the past few years, SDQs have been completed for nearly 100,000 children and adolescents in population-based studies as well as in clinical samples. The largest studies have been performed in Norway and Denmark, and in these countries the diagnostic interview DAWBA has also been used in conjunction with the SDQ. Aims: In addition to a brief overview of past and ongoing SDQ work in Sweden, Finland, Norway, Denmark, and Iceland, we present scale means and standard deviations from selected community studies with comparable age groups, including parental reports for 7, 9 and 11 year-old children and self-reports of 13 and 15 year-olds. Conclusions: The descriptive statistics suggest that the distributions of SDQ scores are very similar across the Nordic countries. Further collaborative efforts in establishing norms and evaluating the validity of the SDQ as a screening instrument are encouraged.