33 research outputs found

    The Origin, Early Evolution and Predictability of Solar Eruptions

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    Coronal mass ejections (CMEs) were discovered in the early 1970s when space-borne coronagraphs revealed that eruptions of plasma are ejected from the Sun. Today, it is known that the Sun produces eruptive flares, filament eruptions, coronal mass ejections and failed eruptions; all thought to be due to a release of energy stored in the coronal magnetic field during its drastic reconfiguration. This review discusses the observations and physical mechanisms behind this eruptive activity, with a view to making an assessment of the current capability of forecasting these events for space weather risk and impact mitigation. Whilst a wealth of observations exist, and detailed models have been developed, there still exists a need to draw these approaches together. In particular more realistic models are encouraged in order to asses the full range of complexity of the solar atmosphere and the criteria for which an eruption is formed. From the observational side, a more detailed understanding of the role of photospheric flows and reconnection is needed in order to identify the evolutionary path that ultimately means a magnetic structure will erupt

    Fine-Scale Mapping of the 4q24 Locus Identifies Two Independent Loci Associated with Breast Cancer Risk

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    Background: A recent association study identified a common variant (rs9790517) at 4q24 to be associated with breast cancer risk. Independent association signals and potential functional variants in this locus have not been explored. Methods: We conducted a fine-mapping analysis in 55,540 breast cancer cases and 51,168 controls from the Breast Cancer Association Consortium. Results: Conditional analyses identified two independent association signals among women of European ancestry, represented by rs9790517 [conditional P = 2.51 × 10−4; OR, 1.04; 95% confidence interval (CI), 1.02–1.07] and rs77928427 (P = 1.86 × 10−4; OR, 1.04; 95% CI, 1.02–1.07). Functional annotation using data from the Encyclopedia of DNA Elements (ENCODE) project revealed two putative functional variants, rs62331150 and rs73838678 in linkage disequilibrium (LD) with rs9790517 (r2 ≥ 0.90) residing in the active promoter or enhancer, respectively, of the nearest gene, TET2. Both variants are located in DNase I hypersensitivity and transcription factor–binding sites. Using data from both The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), we showed that rs62331150 was associated with level of expression of TET2 in breast normal and tumor tissue. Conclusion: Our study identified two independent association signals at 4q24 in relation to breast cancer risk and suggested that observed association in this locus may be mediated through the regulation of TET2. Impact: Fine-mapping study with large sample size warranted for identification of independent loci for breast cancer risk

    Desert Frontier: Ecological and Economic Change Along the Western Sahel 1600- 1850

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    Association of a functional variant downstream of TNFAIP3 with systemic lupus erythematosus

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    Systemic lupus erythematosus (SLE, MIM152700) is an autoimmune disease characterized by self-reactive antibodies resulting in systemic inflammation and organ failure. TNFAIP3, encoding the ubiquitin-modifying enzyme A20, is an established susceptibility locus for SLE. By fine mapping and genomic re-sequencing in ethnically diverse populations, we fully characterized the TNFAIP3 risk haplotype and identified a TT and gt;A polymorphic dinucleotide (deletion T followed by a T to A transversion) associated with SLE in subjects of European (P = 1.58 × 10-8, odds ratio = 1.70) and Korean (P = 8.33 × 10-10, odds ratio = 2.54) ancestry. This variant, located in a region of high conservation and regulatory potential, bound a nuclear protein complex composed of NF-?B subunits with reduced avidity. Further, compared with the non-risk haplotype, the haplotype carrying this variant resulted in reduced TNFAIP3 mRNA and A20 protein expression. These results establish this TT and gt;A variant as the most likely functional polymorphism responsible for the association between TNFAIP3 and SLE. © 2011 Nature America, Inc. All rights reserved

    Association of a functional variant downstream of TNFAIP3 with systemic lupus erythematosus

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    Systemic lupus erythematosus (SLE, MIM152700) is an autoimmune disease characterized by self-reactive antibodies resulting in systemic inflammation and organ failure. TNFAIP3, encoding the ubiquitin-modifying enzyme A20, is an established susceptibility locus for SLE. By fine mapping and genomic re-sequencing in ethnically diverse populations, we fully characterized the TNFAIP3 risk haplotype and identified a TT and gt;A polymorphic dinucleotide (deletion T followed by a T to A transversion) associated with SLE in subjects of European (P = 1.58 × 10-8, odds ratio = 1.70) and Korean (P = 8.33 × 10-10, odds ratio = 2.54) ancestry. This variant, located in a region of high conservation and regulatory potential, bound a nuclear protein complex composed of NF-?B subunits with reduced avidity. Further, compared with the non-risk haplotype, the haplotype carrying this variant resulted in reduced TNFAIP3 mRNA and A20 protein expression. These results establish this TT and gt;A variant as the most likely functional polymorphism responsible for the association between TNFAIP3 and SLE. © 2011 Nature America, Inc. All rights reserved

    Crônica de uma praga anunciada epidemias agrícolas e história ambiental do café nas Américas Chronicle of a plague foretold crop epidemics and the environmental history of coffee in the Americas

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    As epidemias agrícolas fornecem um ponto de vista privilegiado para a história ambiental global e transnacional de commodities. A epidemia da ferrugem, causada pelo fungo Hemileia nastatrix, é uma das mais sérias doenças que têm atingido a indústria global de café. No século XIX, ela devastou as plantações de café no Velho Mundo. Também reduziu agudamente a produção de café do tipo arábica na África, Ásia e no Pacífico. Esse foi um dos fatores que permitiu aos países da Américas dominarem a produção global no século XX. Essa epidemia foi detectada nas Américas pela primeira vez na década de 1970. A sua história nas Américas, e as tentativas de seu controle lançam luzes sobre dois paradigmas maiores que moldaram a história ambiental do café no final do século XX. São eles: o paradigma tecnicista, dominante entre meados do século XX até o início dos anos 1990; e o paradigma da sustentabilidade, cujo domínio emergiu em meados dos anos 1980 e se mantém até o presente.<br>Crop epidemics provide a portal into the global and transnational environmental history of commodities. The coffee rust epidemic, caused by the fungus Hemileia vastatrix, is one of the most serious diseases to have afflicted the global coffee industry. In the nineteenth century, it devastated the coffee plantations in the Old World. It sharply curtailed arabica coffee production in Africa, Asia, and the Pacific. This was one of the factors that allowed the Americas do dominate global coffee production in the twentieth century. The coffee rust epidemic was first detected in the Americas in the 1970s. The history of the rust epidemic in the Americas, and attempts to control it, shed light on two major paradigms that shaped the environmental history of coffee in the late twentieth century. The paradigm of technification, which dominated from the mid-20th century to the early 1990s; and the paradigm of sustainability, which dominated emerged in the mid-1980s and continues to the present
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