| 1. |
- Cohen, J., et al.
(författare)
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Divergent consensuses on Arctic amplification influence on midlatitude severe winter weather
- 2020
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Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 10, s. 20-29
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Forskningsöversikt (refereegranskat)abstract
- The Arctic has warmed more than twice as fast as the global average since the late twentieth century, a phenomenon known as Arctic amplification (AA). Recently, there have been considerable advances in understanding the physical contributions to AA, and progress has been made in understanding the mechanisms that link it to midlatitude weather variability. Observational studies overwhelmingly support that AA is contributing to winter continental cooling. Although some model experiments support the observational evidence, most modelling results show little connection between AA and severe midlatitude weather or suggest the export of excess heating from the Arctic to lower latitudes. Divergent conclusions between model and observational studies, and even intramodel studies, continue to obfuscate a clear understanding of how AA is influencing midlatitude weather.
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| 2. |
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| 3. |
- Crotty Alexander, Laura E., et al.
(författare)
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Myeloid cell HIF-1 alpha regulates asthma airway resistance and eosinophil function
- 2013
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Ingår i: Journal of Molecular Medicine. - : Springer Verlag (Germany). - 0946-2716 .- 1432-1440. ; 91:5, s. 637-644
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Tidskriftsartikel (refereegranskat)abstract
- Hypoxia-inducible factor (HIF)-1 alpha is a master regulator of inflammatory activities of myeloid cells, including neutrophils and macrophages. These studies examine the role of myeloid cell HIF-1 alpha in regulating asthma induction and pathogenesis, and for the first time, evaluate the roles of HIF-1 alpha and HIF-2 alpha in the chemotactic properties of eosinophils, the myeloid cells most associated with asthma. Wild-type (WT) and myeloid cell-specific HIF-1 alpha knockout (KO) C57BL/6 mice were studied in an ovalbumin (OVA) model of asthma. Administration of the pharmacological HIF-1 alpha antagonist YC-1 was used to corroborate findings from the genetic model. WT, HIF-1 alpha, and HIF-2 alpha KO eosinophils underwent in vitro chemotaxis assays. We found that deletion of HIF-1 alpha in myeloid cells and systemic treatment with YC-1 during asthma induction decreased airway hyperresponsiveness (AHR). Deletion of HIF-1 alpha in myeloid cells in OVA-induced asthma also reduced eosinophil infiltration, goblet cell hyperplasia, and levels of cytokines IL-4, IL-5, and IL-13 in the lung. HIF-1 alpha inhibition with YC-1 during asthma induction decreased eosinophilia in bronchoalveolar lavage, lung parenchyma, and blood, as well as decreased total lung inflammation, IL-5, and serum OVA-specific IgE levels. Deletion of HIF-1 alpha in eosinophils decreased their chemotaxis, while deletion of the isoform HIF-2 alpha led to increased chemotaxis. This work demonstrates that HIF-1 alpha in myeloid cells plays a role in asthma pathogenesis, particularly in AHR development. Additionally, treatment with HIF-1 alpha inhibitors during asthma induction decreases AHR and eosinophilia. Finally, we show that HIF-1 alpha and HIF-2 alpha regulate eosinophil migration in opposing ways.
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| 4. |
- ELPHINSTONE, RD, et al.
(författare)
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OBSERVATIONS IN THE VICINITY OF SUBSTORM ONSET - IMPLICATIONS FOR THE SUBSTORM PROCESS
- 1995
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Ingår i: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS. - : AMER GEOPHYSICAL UNION. - 0148-0227. ; 100:A5, s. 7937-7969
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Multi-instrument data sets from the ground and satellites at both low and high altitude have provided new results concerning substorm onset and its source region in the magnetosphere. Twenty-six out of 37 substorm onset events showed evidence of azimuthal
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