| 1. |
- Acciari, V. A., et al.
(författare)
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Radio Imaging of the Very-High-Energy gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 325:5939, s. 444-448
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Tidskriftsartikel (refereegranskat)abstract
- The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.
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| 2. |
- Elsik, Christine G., et al.
(författare)
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The Genome Sequence of Taurine Cattle : A Window to Ruminant Biology and Evolution
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 324:5926, s. 522-528
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Tidskriftsartikel (refereegranskat)abstract
- To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
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| 3. |
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| 4. |
- Adewumi, Oluseun, et al.
(författare)
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Characterization of human embryonic stem cell lines by the International Stem Cell Initiative
- 2007
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Ingår i: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1087-0156 .- 1546-1696. ; 25:7, s. 803-816
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Tidskriftsartikel (refereegranskat)abstract
- The International Stem Cell Initiative characterized 59 human embryonic stem cell lines from 17 laboratories worldwide. Despite diverse genotypes and different techniques used for derivation and maintenance, all lines exhibited similar expression patterns for several markers of human embryonic stem cells. They expressed the glycolipid antigens SSEA3 and SSEA4, the keratan sulfate antigens TRA-1-60, TRA-1-81, GCTM2 and GCT343, and the protein antigens CD9, Thy1 (also known as CD90), tissue- nonspecific alkaline phosphatase and class 1 HLA, as well as the strongly developmentally regulated genes NANOG, POU5F1 (formerly known as OCT4), TDGF1, DNMT3B, GABRB3 and GDF3. Nevertheless, the lines were not identical: differences in expression of several lineage markers were evident, and several imprinted genes showed generally similar allele-specific expression patterns, but some gene-dependent variation was observed. Also, some female lines expressed readily detectable levels of XIST whereas others did not. No significant contamination of the lines with mycoplasma, bacteria or cytopathic viruses was detected.
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| 5. |
- Beck, R., et al.
(författare)
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GPSDTN : Predictive velocity-enabled delay-tolerant networks for arctic research and sustainability
- 2007
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Ingår i: Second International Conference on Internet Monitoring and Protection (ICIMP 2007). - Los Alamitos, Calif : IEEE Computer Society Press. - 9780769529110
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Konferensbidrag (refereegranskat)abstract
- A Delay-Tolerant Network (DTN) is a necessity for communication nodes that may need to wait for long periods to form networks. The IETF Delay Tolerant Network Research Group is developing protocols to enable such networks for a broad variety of Earth and interplanetary applications. The Arctic would benefit from a predictive velocity-enabled version of DTN that would facilitate communications between sparse, ephemeral, often mobile and extremely power-limited nodes. We propose to augment DTN with power-aware, buffer-aware location- and time-based predictive routing for ad-hoc meshes to create networks that are inherently location and time (velocity) aware at the network level to support climate research, emergency services and rural education in the Arctic. On Earth, the primary source of location and universal time information for networks is the Global Positioning System (GPS). We refer to this Arctic velocity-enabled Delay-Tolerant Network protocol as "GPSDTN" accordingly. This paper describes our requirements analysis and general implementation strategy for GPSDTN to support Arctic research and sustainability efforts
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| 6. |
- Gateva, Vesela, et al.
(författare)
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A large-scale replication study identifies TNIP1, PRDM1, JAZF1, UHRF1BP1 and IL10 as risk loci for systemic lupus erythematosus
- 2009
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 41:11, s. 1228-1233
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies have recently identified at least 15 susceptibility loci for systemic lupus erythematosus (SLE). To confirm additional risk loci, we selected SNPs from 2,466 regions that showed nominal evidence of association to SLE (P < 0.05) in a genome-wide study and genotyped them in an independent sample of 1,963 cases and 4,329 controls. This replication effort identified five new SLE susceptibility loci (P < 5 x 10(-8)): TNIP1 (odds ratio (OR) = 1.27), PRDM1 (OR = 1.20), JAZF1 (OR = 1.20), UHRF1BP1 (OR = 1.17) and IL10 (OR = 1.19). We identified 21 additional candidate loci with P< or = 1 x 10(-5). A candidate screen of alleles previously associated with other autoimmune diseases suggested five loci (P < 1 x 10(-3)) that may contribute to SLE: IFIH1, CFB, CLEC16A, IL12B and SH2B3. These results expand the number of confirmed and candidate SLE susceptibility loci and implicate several key immunologic pathways in SLE pathogenesis.
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| 7. |
- Chung, Sharon A, et al.
(författare)
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European population substructure is associated with mucocutaneous manifestations and autoantibody production in systemic lupus erythematosus
- 2009
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 60:8, s. 2448-2456
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine whether genetic substructure in European-derived populations is associated with specific manifestations of systemic lupus erythematosus (SLE), including mucocutaneous phenotypes, autoantibody production, and renal disease. METHODS: SLE patients of European descent (n=1,754) from 8 case collections were genotyped for >1,400 ancestry informative markers that define a north-south gradient of European substructure. Using the Structure program, each SLE patient was characterized in terms of percent Northern (versus percent Southern) European ancestry based on these genetic markers. Nonparametric methods, including tests for trend, were used to identify associations between Northern European ancestry and specific SLE manifestations. RESULTS: In multivariate analyses, increasing levels of Northern European ancestry were significantly associated with photosensitivity (Ptrend=0.0021, odds ratio for highest quartile of Northern European ancestry versus lowest quartile [ORhigh-low] 1.64, 95% confidence interval [95% CI] 1.13-2.35) and discoid rash (Ptrend=0.014, ORhigh-low 1.93, 95% CI 0.98-3.83). In contrast, increasing levels of Northern European ancestry had a protective effect against the production of anticardiolipin autoantibodies (Ptrend=1.6x10(-4), ORhigh-low 0.46, 95% CI 0.30-0.69) and anti-double-stranded DNA autoantibodies (Ptrend=0.017, ORhigh-low 0.67, 95% CI 0.46-0.96). CONCLUSION: This study demonstrates that specific SLE manifestations vary according to Northern versus Southern European ancestry. Thus, genetic ancestry may contribute to the clinical heterogeneity and variation in disease outcomes among SLE patients of European descent. Moreover, these results suggest that genetic studies of SLE subphenotypes will need to carefully address issues of population substructure based on genetic ancestry.
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