| 1. |
- Speliotes, Elizabeth K., et al.
(författare)
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Association analyses of 249,796 individuals reveal 18 new loci associated with body mass index
- 2010
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:11, s. 937-948
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is globally prevalent and highly heritable, but its underlying genetic factors remain largely elusive. To identify genetic loci for obesity susceptibility, we examined associations between body mass index and ~2.8 million SNPs in up to 123,865 individuals with targeted follow up of 42 SNPs in up to 125,931 additional individuals. We confirmed 14 known obesity susceptibility loci and identified 18 new loci associated with body mass index (P < 5 × 10−8), one of which includes a copy number variant near GPRC5B. Some loci (at MC4R, POMC, SH2B1 and BDNF) map near key hypothalamic regulators of energy balance, and one of these loci is near GIPR, an incretin receptor. Furthermore, genes in other newly associated loci may provide new insights into human body weight regulation.
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| 2. |
- Lango Allen, Hana, et al.
(författare)
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Hundreds of variants clustered in genomic loci and biological pathways affect human height.
- 2010
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 467:7317, s. 832-8
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Tidskriftsartikel (refereegranskat)abstract
- Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P<0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.
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| 3. |
- Berndt, Sonja I., et al.
(författare)
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Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:5, s. 501-U69
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Tidskriftsartikel (refereegranskat)abstract
- Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.
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| 4. |
- Heid, Iris M, et al.
(författare)
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Meta-analysis identifies 13 new loci associated with waist-hip ratio and reveals sexual dimorphism in the genetic basis of fat distribution
- 2010
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:11, s. 949-960
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Tidskriftsartikel (refereegranskat)abstract
- Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻¹³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions.
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| 5. |
- Antoniou, Antonis C., et al.
(författare)
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Common alleles at 6q25.1 and 1p11.2 are associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers
- 2011
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 20:16, s. 3304-3321
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Tidskriftsartikel (refereegranskat)abstract
- Two single nucleotide polymorphisms (SNPs) at 6q25.1, near the ESR1 gene, have been implicated in the susceptibility to breast cancer for Asian (rs2046210) and European women (rs9397435). A genome-wide association study in Europeans identified two further breast cancer susceptibility variants: rs11249433 at 1p11.2 and rs999737 in RAD51L1 at 14q24.1. Although previously identified breast cancer susceptibility variants have been shown to be associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers, the involvement of these SNPs to breast cancer susceptibility in mutation carriers is currently unknown. To address this, we genotyped these SNPs in BRCA1 and BRCA2 mutation carriers from 42 studies from the Consortium of Investigators of Modifiers of BRCA1/2. In the analysis of 14 123 BRCA1 and 8053 BRCA2 mutation carriers of European ancestry, the 6q25.1 SNPs (r(2) = 0.14) were independently associated with the risk of breast cancer for BRCA1 mutation carriers [ hazard ratio (HR) = 1.17, 95% confidence interval (CI): 1.11-1.23, P-trend = 4.5 x 10(-9) for rs2046210; HR = 1.28, 95% CI: 1.18-1.40, P-trend = 1.3 x 10(-8) for rs9397435], but only rs9397435 was associated with the risk for BRCA2 carriers (HR = 1.14, 95% CI: 1.01-1.28, P-trend = 0.031). SNP rs11249433 (1p11.2) was associated with the risk of breast cancer for BRCA2 mutation carriers (HR = 1.09, 95% CI: 1.02-1.17, P-trend = 0.015), but was not associated with breast cancer risk for BRCA1 mutation carriers (HR = 0.97, 95% CI: 0.92-1.02, P-trend = 0.20). SNP rs999737 (RAD51L1) was not associated with breast cancer risk for either BRCA1 or BRCA2 mutation carriers (P-trend = 0.27 and 0.30, respectively). The identification of SNPs at 6q25.1 associated with breast cancer risk for BRCA1 mutation carriers will lead to a better understanding of the biology of tumour development in these women.
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| 6. |
- Elks, Cathy E, et al.
(författare)
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Thirty new loci for age at menarche identified by a meta-analysis of genome-wide association studies
- 2010
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:12, s. 1077-85
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Tidskriftsartikel (refereegranskat)abstract
- To identify loci for age at menarche, we performed a meta-analysis of 32 genome-wide association studies in 87,802 women of European descent, with replication in up to 14,731 women. In addition to the known loci at LIN28B (P = 5.4 × 10⁻⁶⁰) and 9q31.2 (P = 2.2 × 10⁻³³), we identified 30 new menarche loci (all P < 5 × 10⁻⁸) and found suggestive evidence for a further 10 loci (P < 1.9 × 10⁻⁶). The new loci included four previously associated with body mass index (in or near FTO, SEC16B, TRA2B and TMEM18), three in or near other genes implicated in energy homeostasis (BSX, CRTC1 and MCHR2) and three in or near genes implicated in hormonal regulation (INHBA, PCSK2 and RXRG). Ingenuity and gene-set enrichment pathway analyses identified coenzyme A and fatty acid biosynthesis as biological processes related to menarche timing.
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| 7. |
- Estrada, Karol, et al.
(författare)
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Genome-wide meta-analysis identifies 56 bone mineral density loci and reveals 14 loci associated with risk of fracture.
- 2012
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 44:5, s. 491-501
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Tidskriftsartikel (refereegranskat)abstract
- Bone mineral density (BMD) is the most widely used predictor of fracture risk. We performed the largest meta-analysis to date on lumbar spine and femoral neck BMD, including 17 genome-wide association studies and 32,961 individuals of European and east Asian ancestry. We tested the top BMD-associated markers for replication in 50,933 independent subjects and for association with risk of low-trauma fracture in 31,016 individuals with a history of fracture (cases) and 102,444 controls. We identified 56 loci (32 new) associated with BMD at genome-wide significance (P < 5 × 10(-8)). Several of these factors cluster within the RANK-RANKL-OPG, mesenchymal stem cell differentiation, endochondral ossification and Wnt signaling pathways. However, we also discovered loci that were localized to genes not known to have a role in bone biology. Fourteen BMD-associated loci were also associated with fracture risk (P < 5 × 10(-4), Bonferroni corrected), of which six reached P < 5 × 10(-8), including at 18p11.21 (FAM210A), 7q21.3 (SLC25A13), 11q13.2 (LRP5), 4q22.1 (MEPE), 2p16.2 (SPTBN1) and 10q21.1 (DKK1). These findings shed light on the genetic architecture and pathophysiological mechanisms underlying BMD variation and fracture susceptibility.
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| 8. |
- Loth, Daan W, et al.
(författare)
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Genome-wide association analysis identifies six new loci associated with forced vital capacity
- 2014
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 46, s. 669-677
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Tidskriftsartikel (refereegranskat)abstract
- Forced vital capacity (FVC), a spirometric measure of pulmonary function, reflects lung volume and is used to diagnose and monitor lung diseases. We performed genome-wide association study meta-analysis of FVC in 52,253 individuals from 26 studies and followed up the top associations in 32,917 additional individuals of European ancestry. We found six new regions associated at genome-wide significance (P < 5 × 10(-8)) with FVC in or near EFEMP1, BMP6, MIR129-2-HSD17B12, PRDM11, WWOX and KCNJ2. Two loci previously associated with spirometric measures (GSTCD and PTCH1) were related to FVC. Newly implicated regions were followed up in samples from African-American, Korean, Chinese and Hispanic individuals. We detected transcripts for all six newly implicated genes in human lung tissue. The new loci may inform mechanisms involved in lung development and the pathogenesis of restrictive lung disease.
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| 9. |
- Durakiewicz, T., et al.
(författare)
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Quest for Band Renormalization and Self-Energy in Correlated f-Electron Systems
- 2010
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Ingår i: Acta Physica Polonica. A. - 0587-4246 .- 1898-794X. ; 117:2, s. 264-267
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Tidskriftsartikel (refereegranskat)abstract
- Coexisting low-energy scales are observed in f-electron materials. The information about some of low-energy scales is imprinted in the electron self-energy, which can be measured by angle-resolved photoemission (ARPES). Such measurements in d-electron materials over the last decade were based on high energy- and momentum-resolution ARPES techniques used to extract the self-energy information from measured spectra. Simultaneously, many-body theoretical approaches have been developed to find a link between the self-energy and many-body interactions. Here we show the transcription of such methods from d-electrons to f-electrons by presenting the first example of low energy scales in the f-electron material USb2, measured with synchrotron-based ARPES. The proposed approach will help in answering the fundamental questions about the complex nature of the heavy fermion state.
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| 10. |
- Oei, Ling, et al.
(författare)
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A genome-wide copy number association study of osteoporotic fractures points to the 6p25.1 locus
- 2014
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Ingår i: Journal of Medical Genetics. - : BMJ Publishing Group. - 0022-2593 .- 1468-6244. ; 51:2, s. 122-131
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Osteoporosis is a systemic skeletal disease characterised by reduced bone mineral density and increased susceptibility to fracture; these traits are highly heritable. Both common and rare copy number variants (CNVs) potentially affect the function of genes and may influence disease risk.AIM: To identify CNVs associated with osteoporotic bone fracture risk.METHOD: We performed a genome-wide CNV association study in 5178 individuals from a prospective cohort in the Netherlands, including 809 osteoporotic fracture cases, and performed in silico lookups and de novo genotyping to replicate in several independent studies.RESULTS: A rare (population prevalence 0.14%, 95% CI 0.03% to 0.24%) 210 kb deletion located on chromosome 6p25.1 was associated with the risk of fracture (OR 32.58, 95% CI 3.95 to 1488.89; p=8.69×10(-5)). We performed an in silico meta-analysis in four studies with CNV microarray data and the association with fracture risk was replicated (OR 3.11, 95% CI 1.01 to 8.22; p=0.02). The prevalence of this deletion showed geographic diversity, being absent in additional samples from Australia, Canada, Poland, Iceland, Denmark, and Sweden, but present in the Netherlands (0.34%), Spain (0.33%), USA (0.23%), England (0.15%), Scotland (0.10%), and Ireland (0.06%), with insufficient evidence for association with fracture risk.CONCLUSIONS: These results suggest that deletions in the 6p25.1 locus may predispose to higher risk of fracture in a subset of populations of European origin; larger and geographically restricted studies will be needed to confirm this regional association. This is a first step towards the evaluation of the role of rare CNVs in osteoporosis.
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| 11. |
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| 12. |
- Wang, Thomas J, et al.
(författare)
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Common genetic determinants of vitamin D insufficiency: a genome-wide association study.
- 2010
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Ingår i: Lancet. - 1474-547X. ; 376:9736, s. 180-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Vitamin D is crucial for maintenance of musculoskeletal health, and might also have a role in extraskeletal tissues. Determinants of circulating 25-hydroxyvitamin D concentrations include sun exposure and diet, but high heritability suggests that genetic factors could also play a part. We aimed to identify common genetic variants affecting vitamin D concentrations and risk of insufficiency. METHODS: We undertook a genome-wide association study of 25-hydroxyvitamin D concentrations in 33 996 individuals of European descent from 15 cohorts. Five epidemiological cohorts were designated as discovery cohorts (n=16 125), five as in-silico replication cohorts (n=9367), and five as de-novo replication cohorts (n=8504). 25-hydroxyvitamin D concentrations were measured by radioimmunoassay, chemiluminescent assay, ELISA, or mass spectrometry. Vitamin D insufficiency was defined as concentrations lower than 75 nmol/L or 50 nmol/L. We combined results of genome-wide analyses across cohorts using Z-score-weighted meta-analysis. Genotype scores were constructed for confirmed variants. FINDINGS: Variants at three loci reached genome-wide significance in discovery cohorts for association with 25-hydroxyvitamin D concentrations, and were confirmed in replication cohorts: 4p12 (overall p=1.9x10(-109) for rs2282679, in GC); 11q12 (p=2.1x10(-27) for rs12785878, near DHCR7); and 11p15 (p=3.3x10(-20) for rs10741657, near CYP2R1). Variants at an additional locus (20q13, CYP24A1) were genome-wide significant in the pooled sample (p=6.0x10(-10) for rs6013897). Participants with a genotype score (combining the three confirmed variants) in the highest quartile were at increased risk of having 25-hydroxyvitamin D concentrations lower than 75 nmol/L (OR 2.47, 95% CI 2.20-2.78, p=2.3x10(-48)) or lower than 50 nmol/L (1.92, 1.70-2.16, p=1.0x10(-26)) compared with those in the lowest quartile. INTERPRETATION: Variants near genes involved in cholesterol synthesis, hydroxylation, and vitamin D transport affect vitamin D status. Genetic variation at these loci identifies individuals who have substantially raised risk of vitamin D insufficiency. FUNDING: Full funding sources listed at end of paper (see Acknowledgments).
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| 13. |
- Avan, Evan Y., et al.
(författare)
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Experimental and numerical investigations of oil film formation and friction in a piston ring–liner contact
- 2013
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Ingår i: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology. - : SAGE Publications. - 1350-6501 .- 2041-305X. ; 227:2, s. 126-140
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Tidskriftsartikel (refereegranskat)abstract
- The piston ring–cylinder liner contact is a major source of the total parasitic losses in an internal combustion engine. The lubrication process of this contact highly influences the amount of friction, oil consumption and wear that occurs. In this work, a reciprocating test rig combined with an ultrasonic film thickness measurement system was developed and then used for tribological investigation of the piston ring–cylinder liner contact under idealised cold conditions. A special piston ring and cylinder liner holder were designed and five sensors were glued on to the back side of the liner specimen. Ultrasonic reflections captured by the sensors, used to obtain the film thickness, and friction were continuously recorded as the piston ring section reciprocated over the liner. Several experiments were performed at different speed and load conditions. Furthermore, a numerical model has been developed to predict film thickness and friction in all lubrication regimes. The experimentally measured film thickness and friction were compared with the output from the numerical model and good correlation was found. The parameters affecting the accuracy of the ultrasound measurements and numerical simulations of film thickness and friction are then discussed.
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| 14. |
- Evangelou, Evangelos, et al.
(författare)
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A meta-analysis of genome-wide association studies identifies novel variants associated with osteoarthritis of the hip
- 2014
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 73:12, s. 2130-2136
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Osteoarthritis (OA) is the most common form of arthritis with a clear genetic component. To identify novel loci associated with hip OA we performed a meta-analysis of genome-wide association studies (GWAS) on European subjects. Methods We performed a two-stage meta-analysis on more than 78 000 participants. In stage 1, we synthesised data from eight GWAS whereas data from 10 centres were used for 'in silico' or 'de novo' replication. Besides the main analysis, a stratified by sex analysis was performed to detect possible sex-specific signals. Meta-analysis was performed using inverse-variance fixed effects models. A random effects approach was also used. Results We accumulated 11 277 cases of radiographic and symptomatic hip OA. We prioritised eight single nucleotide polymorphism (SNPs) for follow-up in the discovery stage (4349 OA cases); five from the combined analysis, two male specific and one female specific. One locus, at 20q13, represented by rs6094710 (minor allele frequency (MAF) 4%) near the NCOA3 (nuclear receptor coactivator 3) gene, reached genome-wide significance level with p=7.9x10(-9) and OR=1.28 (95% CI 1.18 to 1.39) in the combined analysis of discovery (p= 5.6x10(-8)) and follow-up studies (p=7.3x10(-4)). We showed that this gene is expressed in articular cartilage and its expression was significantly reduced in OA-affected cartilage. Moreover, two loci remained suggestive associated; rs5009270 at 7q31 (MAF 30%, p=9.9x10(-7), OR=1.10) and rs3757837 at 7p13 (MAF 6%, p=2.2x10(-6), OR=1.27 in male specific analysis). Conclusions Novel genetic loci for hip OA were found in this meta-analysis of GWAS.
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| 15. |
- Gremel, G., et al.
(författare)
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Functional and prognostic relevance of the homeobox protein MSX2 in malignant melanoma
- 2011
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 105:4, s. 565-574
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The homeobox containing transcription factor MSX2 is a key regulator of embryonic development and has been implicated to have a role in breast and pancreatic cancer. METHODS: Using a selection of two-and three-dimensional in vitro assays and tissue microarrays (TMAs), the clinical and functional relevance of MSX2 in malignant melanoma was explored. A doxycyline-inducible over-expression system was applied to study the relevance of MSX2 in vitro. For TMA construction, tumour material from 218 melanoma patients was used. RESULTS: Ectopic expression of MSX2 resulted in the induction of apoptosis and reduced the invasive capacity of melanoma cells in three-dimensional culture. MSX2 over-expression was shown to affect several signalling pathways associated with cell invasion and survival. Downregulation of N-Cadherin, induction of p21 and inhibition of both BCL2 and Survivin were observed. Cytoplasmic MSX2 expression was found to correlate significantly with increased recurrence-free survival (P = 0.008). Nuclear expression of MSX2 did not result in significant survival correlations, suggesting that the beneficial effect of MSX2 may be independent of its DNA binding activity. CONCLUSIONS: MSX2 may be an important regulator of melanoma cell invasion and survival. Cytoplasmic expression of the protein was identified as biomarker for good prognosis in malignant melanoma patients.
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| 16. |
- Hunter, K. E., et al.
(författare)
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Heparanase promotes lymphangiogenesis and tumor invasion in pancreatic neuroendocrine tumors
- 2014
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 33:14, s. 1799-1808
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Tidskriftsartikel (refereegranskat)abstract
- Heparan sulfate proteoglycans are an important and abundant component of the extracellular matrix, which undergo substantial remodeling throughout tumorigenesis via the enzymatic activity of heparanase. Heparanase has been shown to be upregulated in many human cancers; however, its specific functions in human pancreatic neuroendocrine tumors (PanNETs) and spontaneous mouse models of cancer have not been evaluated. Here, we investigated the role of heparanase in PanNETs using patient samples and the RIP1-Tag2 (RT2) PanNET-transgenic mouse model. High heparanase expression significantly correlated with more advanced tumor stage, higher tumor grade and the presence of distant metastasis in PanNET patients. We genetically manipulated heparanase levels in the RT2 model using heparanase-transgenic mice, which constitutively overexpress heparanase, and heparanase-knockout mice. Heparanase was found to have a critical role in promoting tumor invasion, through both macrophage and cancer cell sources in the tumor microenvironment. In addition, elevated heparanase levels significantly increased peritumoral lymphangiogenesis in vivo and promoted the trans-differentiation of macrophages into lymphatic endothelial cell-like structures in culture. Conversely, we found that heparanase deletion led to increased angiogenesis and pericyte coverage. Together, these data identify important roles for heparanase in regulating several critical aspects of tumorigenesis, demonstrating that heparanase represents a potential therapeutic target for PanNET patients.
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| 17. |
- Lewis, R., et al.
(författare)
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Mapping railway wheel material wear mechanisms and transitions
- 2010
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Ingår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - 0954-4097 .- 2041-3017. ; 224:F3, s. 125-137
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Tidskriftsartikel (refereegranskat)abstract
- In order to develop more durable wheel materials to cope with the new specifications being imposed on wheel wear, a greater understanding of the wear mechanisms and transitions occurring in wheel steels is needed, particularly at higher load and slip conditions. The aim of this work was to draw together current understanding of the wear mechanisms, regimes, and transitions (particularly with R8T wheel material) and new tests on R7T wheel material; to identify gaps in the knowledge; and to develop new tools for assessing wear of wheel materials, such as wear maps, that can be used to improve wear prediction. Wear assessment of wheel materials, as well as wear rates, regimes, and transitions, is discussed. Twin disc wear testing, used extensively for studying wear of wheel and rail materials, has indicated that three wear regimes exist for wheel materials: mild, severe, and catastrophic. These have been classified in terms of wear rate and features. Wear rates are seen to increase steadily initially and then level off, before increasing rapidly as the severity of the contact conditions is increased. Analysis of the contact conditions in terms of friction and slip has indicated that the levelling off of the wear rate observed at the first wear transition is caused by the change from partial slip to full slip conditions at the disc interface. Temperature calculations for the contact showed that the large increase in wear rates seen at the second wear transition may result from a thermally induced reduction in yield strength and other material properties. Comparisons made between discs and actual wheels have provided some support for the theories relating to the transitions observed. Wear maps have been produced using the test results to study how individual contact parameters such as load and sliding speed influence wear rates and transitions. The maps are also correlated to expected wheel-rail contact conditions. This improved understanding of wheel wear mechanisms and transitions will help in the aim of eventually attaining a wear modelling methodology reliant on material properties rather than on wear constants derived from testing.
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| 18. |
- Liu, Ching-Ti, et al.
(författare)
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Assessment of gene-by-sex interaction effect on bone mineral density
- 2012
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 1523-4681 .- 0884-0431. ; 27:10, s. 2051-2064
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Tidskriftsartikel (refereegranskat)abstract
- Sexual dimorphism in various bone phenotypes, including bone mineral density (BMD), is widely observed; however, the extent to which genes explain these sex differences is unclear. To identify variants with different effects by sex, we examined gene-by-sex autosomal interactions genome-wide, and performed expression quantitative trait loci (eQTL) analysis and bioinformatics network analysis. We conducted an autosomal genome-wide meta-analysis of gene-by-sex interaction on lumbar spine (LS) and femoral neck (FN) BMD in 25,353 individuals from 8 cohorts. In a second stage, we followed up the 12 top single-nucleotide polymorphisms (SNPs; p?
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| 19. |
- Lopes, Renato D., et al.
(författare)
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Highlights from the III International Symposium of Thrombosis and Anticoagulation (ISTA), October 14-16, 2010, Sao Paulo, Brazil
- 2011
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Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 32:2, s. 242-266
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Tidskriftsartikel (refereegranskat)abstract
- To discuss and share knowledge around advances in the care of patients with thrombotic disorders, the Third International Symposium of Thrombosis and Anticoagulation was held in So Paulo, Brazil, from October 14-16, 2010. This scientific program was developed by clinicians for clinicians, and was promoted by four major clinical research institutes: the Brazilian Clinical Research Institute, the Duke Clinical Research Institute of the Duke University School of Medicine, the Canadian VIGOUR Centre, and the Uppsala Clinical Research Center. Comprising 3 days of academic presentations and open discussion, the symposium had as its primary goal to educate, motivate, and inspire internists, cardiologists, hematologists, and other physicians by convening national and international visionaries, thought-leaders, and dedicated clinician-scientists. This paper summarizes the symposium proceedings.
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| 20. |
- Meng, Jian-Qiao, et al.
(författare)
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Imaging the Three-Dimensional Fermi-Surface Pairing near the Hidden-Order Transition in URu2Si2 Using Angle-Resolved Photoemission Spectroscopy
- 2013
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 111:12, s. 127002-
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Tidskriftsartikel (refereegranskat)abstract
- We report angle-resolved photoemission spectroscopy experiments probing deep into the hidden-order state of URu2Si2, utilizing tunable photon energies with sufficient energy and momentum resolution to detect the near Fermi-surface (FS) behavior. Our results reveal (i) the full itinerancy of the 5f electrons, (ii) the crucial three-dimensional k-space nature of the FS and its critical nesting vectors, in good comparison with density-functional theory calculations, and (iii) the existence of hot-spot lines and pairing of states at the FS, leading to FS gapping in the hidden-order phase.
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| 21. |
- Pinto, Rita, et al.
(författare)
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Identification of new cancer biomarkers based on aberrant mucin glycoforms by in situ proximity ligation
- 2012
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Ingår i: Journal of Cellular and Molecular Medicine (Print). - : Wiley. - 1582-1838 .- 1582-4934. ; 16:7, s. 1474-1484
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Tidskriftsartikel (refereegranskat)abstract
- Mucin glycoproteins are major secreted or membrane-bound molecules that, in cancer, show modifications in both the mucin proteins expression and in the O-glycosylation profile, generating some of the most relevant tumour markers in clinical use for decades. Thus far, the identification of these biomarkers has been based on the detection of either the protein or the O-glycan modifications. We therefore aimed to identify the combined mucin and O-glycan features, i.e. specific glycoforms, in an attempt to increase specificity of these cancer biomarkers. Using in situ proximity ligation assays (PLA) based on existing monoclonal antibodies directed to MUC1, MUC2, MUC5AC and MUC6 mucins and to cancer-associated carbohydrate antigens Tn, Sialyl-Tn (STn), T, Sialyl-Lea (SLea) and Sialyl-Lex (SLex) we screened a series of 28 mucinous adenocarcinomas from different locations (stomach, ampulla of Vater, colon, lung, breast and ovary) to detect specific mucin glycoforms. We detected Tn/STn/SLea/SLex-MUC1 and STn/SLea/SLex-MUC2 glycoforms in ≥50% of the cases, with a variable distribution among organs. Some new glycoforms – T/SLea-MUC2, STn/T/SLea/SLex-MUC5AC and STn/T/SLea/SLex-MUC6 – were identified for the first time in the present study in a variable percentage of cases from different organs. In conclusion, application of the PLA technique allowed sensitive detection of specific aberrant mucin glycoforms in cancer, increasing specificity to the use of antibodies either to the mucin protein backbone or the O-glycan haptens alone.
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| 22. |
- Roulland, Sandrine, et al.
(författare)
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t(14;18) Translocation: A Predictive Blood Biomarker for Follicular Lymphoma
- 2014
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Ingår i: Journal of Clinical Oncology. - 1527-7755 .- 0732-183X. ; 32:13, s. 1347-1347
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Tidskriftsartikel (refereegranskat)abstract
- Purpose The (14;18) translocation constitutes both a genetic hallmark and critical early event in the natural history of follicular lymphoma (FL). However, t(14;18) is also detectable in the blood of otherwise healthy persons, and its relationship with progression to disease remains unclear. Here we sought to determine whether t(14;18)-positive cells in healthy individuals represent tumor precursors and whether their detection could be used as an early predictor for FL. Participants and Methods Among 520,000 healthy participants enrolled onto the EPIC (European Prospective Investigation Into Cancer and Nutrition) cohort, we identified 100 who developed FL 2 to 161 months after enrollment. Prediagnostic blood from these and 218 controls were screened for t(14;18) using sensitive polymerase chain reaction-based assays. Results were subsequently validated in an independent cohort (65 case participants; 128 controls). Clonal relationships between t(14;18) cells and FL were also assessed by molecular backtracking of paired prediagnostic blood and tumor samples. Results Clonal analysis of t(14;18) junctions in paired prediagnostic blood versus tumor samples demonstrated that progression to FL occurred from t(14;18)-positive committed precursors. Furthermore, healthy participants at enrollment who developed FL up to 15 years later showed a markedly higher t(14;18) prevalence and frequency than controls (P < .001). Altogether, we estimated a 23-fold higher risk of subsequent FL in blood samples associated with a frequency > 10(-4) (odds ratio, 23.17; 95% CI, 9.98 to 67.31; P < .001). Remarkably, risk estimates remained high and significant up to 15 years before diagnosis. Conclusion High t(14;18) frequency in blood from healthy individuals defines the first predictive biomarker for FL, effective years before diagnosis.
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| 23. |
- Skinningsrud, Beate, et al.
(författare)
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Multiple Loci in the HLA Complex Are Associated with Addison's Disease.
- 2011
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 96, s. 1703-1708
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Tidskriftsartikel (refereegranskat)abstract
- Context: A strong association between autoimmune Addison's disease (AAD) and major histocompatibility complex class II-encoded HLA-DRB1-DQA1-DQB1 haplotypes is well known. Recent evidence from other autoimmune diseases has suggested that class I-encoded HLA-A and HLA-B gene variants confer HLA-DRB1-DQA1-DQB1-independent effects on disease. Objective: We aimed to explore AAD predisposing effects of HLA-A and -B and further investigate the role of MICA and HLA-DRB1-DQA1-DQB1 in a much larger material than has previously been studied. Design: HLA-A, -B, -DRB1, and -DQB1 and a microsatellite in MICA were genotyped in 414 AAD patients and 684 controls of Norwegian origin. Results: The strongest association was observed for the DRB1 locus, in which the DRB1*03:01 and DRB1*04:04 conferred increased risk of AAD, particularly in a heterozygous combination [odds ratio 22.13; 95% confidence interval (11.39-43.98); P = 6 × 10(-20)]. After conditioning on DRB1, association with AAD was still present for HLA-B and MICA, suggesting the presence of additional risk factors. Conclusions: The major histocompatibility complex harbors multiple risk loci for AAD, in which DRB1 appears to represent the main risk factor.
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| 24. |
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| 25. |
- Spencer, Andrew, et al.
(författare)
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An experimental and numerical investigation of frictional losses and film thickness for four cylinder liner variants for a heavy duty diesel engine
- 2013
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Ingår i: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology. - : SAGE Publications. - 1350-6501 .- 2041-305X. ; 227:12, s. 1319-1333
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Tidskriftsartikel (refereegranskat)abstract
- The piston ring pack is the single greatest contributor to mechanical losses in a heavy duty diesel engine, accounting for 1.1–6.8% of the total losses. Therefore, the piston ring-cylinder liner contact is potentially the most rewarding area to study when attempting to reduce mechanical losses in a heavy duty diesel engine. In this work, four different heavy duty diesel engine cylinder liner variants have been tested to evaluate the lubricating conditions that occur when a section of top compression ring is reciprocated against them in a lubricated environment. Two of the cylinder liners were traditional grey cast iron and plateau honed with different honing angles, one had ANS Triboconditioning® applied and the last was plasma sprayed with a stainless steel and ceramic coating, then honed. An experimental test rig was used where friction and film thickness was recorded, by means of an ultrasonic technique. A numerical model was also developed to calculate the friction and film thickness. Comparisons are made between the simulation and experiment, and the four cylinder liner variants are also evaluated. It was found that both simulation and experiment could differentiate between all surfaces and the results from the model and experiment also correlated well with each other. A lower plateau average surface roughness, as exhibited by the ANS Triboconditioning® and plasma liners, led to a significant reduction in friction.
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| 26. |
- Styrkarsdottir, Unnur, et al.
(författare)
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Severe osteoarthritis of the hand associates with common variants within the ALDH1A2 gene and with rare variants at 1p31.
- 2014
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 46:5, s. 498-502
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Tidskriftsartikel (refereegranskat)abstract
- Osteoarthritis is the most common form of arthritis and is a major cause of pain and disability in the elderly. To search for sequence variants that confer risk of osteoarthritis of the hand, we carried out a genome-wide association study (GWAS) in subjects with severe hand osteoarthritis, using variants identified through the whole-genome sequencing of 2,230 Icelanders. We found two significantly associated loci in the Icelandic discovery set: at 15q22 (frequency of 50.7%, odds ratio (OR) = 1.51, P = 3.99 × 10(-10)) in the ALDH1A2 gene and at 1p31 (frequency of 0.02%, OR = 50.6, P = 9.8 × 10(-10)). Among the carriers of the variant at 1p31 is a family with several members in whom the risk allele segregates with osteoarthritis. The variants within the ALDH1A2 gene were confirmed in replication sets from The Netherlands and the UK, yielding an overall association of OR = 1.46 and P = 1.1 × 10(-11) (rs3204689).
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| 27. |
- Sui, Xin, et al.
(författare)
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Parallel clustered low-rank approximation of graphs and its application to link prediction
- 2012
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Ingår i: Proceedings of the International Workshop on Languages and Compilers for Parallel Computing. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783642376573 - 9783642376580 ; , s. 76-95
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Social network analysis has become a major research area that has impact in diverse applications ranging from search engines to product recommendation systems. A major problem in implementing social network analysis algorithms is the sheer size of many social networks, for example, the Facebook graph has more than 900 million vertices and even small networks may have tens of millions of vertices. One solution to dealing with these large graphs is dimensionality reduction using spectral or SVD analysis of the adjacency matrix of the network, but these global techniques do not necessarily take into account local structures or clusters of the network that are critical in network analysis. A more promising approach is clustered low-rank approximation: instead of computing a global low-rank approximation, the adjacency matrix is first clustered, and then a low-rank approximation of each cluster (i.e., diagonal block) is computed. The resulting algorithm is challenging to parallelize not only because of the large size of the data sets in social network analysis, but also because it requires computing with very diverse data structures ranging from extremely sparse matrices to dense matrices. In this paper, we describe the first parallel implementation of a clustered low-rank approximation algorithm for large social network graphs, and use it to perform link prediction in parallel. Experimental results show that this implementation scales well on large distributed-memory machines; for example, on a Twitter graph with roughly 11 million vertices and 63 million edges, our implementation scales by a factor of 86 on 128 processes and takes less than 2300 seconds, while on a much larger Twitter graph with 41 million vertices and 1.2 billion edges, our implementation scales by a factor of 203 on 256 processes with a running time about 4800 seconds.
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