| 1. |
- Ziska, F., et al.
(författare)
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Global sea-to-air flux climatology for bromoform, dibromomethane and methyl iodide
- 2013
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 13:17, s. 8915-8934
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Tidskriftsartikel (refereegranskat)abstract
- Volatile halogenated organic compounds containing bromine and iodine, which are naturally produced in the ocean, are involved in ozone depletion in both the troposphere and stratosphere. Three prominent compounds transporting large amounts of marine halogens into the atmosphere are bromoform (CHBr3), dibromomethane (CH2Br2) and methyl iodide (CH3I). The input of marine halogens to the stratosphere has been estimated from observations and modelling studies using low-resolution oceanic emission scenarios derived from top-down approaches. In order to improve emission inventory estimates, we calculate data-based high resolution global sea-to-air flux estimates of these compounds from surface observations within the HalOcAt (Halocarbons in the Ocean and Atmosphere) database (https://halocat.geomar.de/). Global maps of marine and atmospheric surface concentrations are derived from the data which are divided into coastal, shelf and open ocean regions. Considering physical and biogeochemical characteristics of ocean and atmosphere, the open ocean water and atmosphere data are classified into 21 regions. The available data are interpolated onto a 1 degrees x 1 degrees grid while missing grid values are interpolated with latitudinal and longitudinal dependent regression techniques reflecting the compounds' distributions. With the generated surface concentration climatologies for the ocean and atmosphere, global sea-to-air concentration gradients and sea-to-air fluxes are calculated. Based on these calculations we estimate a total global flux of 1.5/2.5 Gmol Br yr(-1) for CHBr3, 0.78/0.98 Gmol Br yr(-1) for CH2Br2 and 1.24/1.45 Gmol Br yr(-1) for CH3I (robust fit/ordinary least squares regression techniques). Contrary to recent studies, negative fluxes occur in each sea-to-air flux climatology, mainly in the Arctic and Antarctic regions. "Hot spots" for global polybromomethane emissions are located in the equatorial region, whereas methyl iodide emissions are enhanced in the subtropical gyre regions. Inter-annual and seasonal variation is contained within our flux calculations for all three compounds. Compared to earlier studies, our global fluxes are at the lower end of estimates, especially for bromoform. An under-representation of coastal emissions and of extreme events in our estimate might explain the mismatch between our bottom-up emission estimate and top-down approaches.
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| 2. |
- Brinkmalm-Westman, Ann, 1966, et al.
(författare)
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SILAC zebrafish for quantitative analysis of protein turnover and tissue regeneration.
- 2011
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Ingår i: Journal of proteomics. - : Elsevier BV. - 1876-7737 .- 1874-3919. ; 75:2, s. 425-34
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Tidskriftsartikel (refereegranskat)abstract
- Defective tissue regeneration is thought to contribute to several human diseases, including neurodegenerative disorders, heart failure and various lung diseases. Boosting the regenerative capacity has been suggested a possible therapeutic approach. Methods to metabolically label newly synthesized proteins in vivo with stable isotopic forms of amino acids holds promise for the study of protein turnover and tissue regeneration that are fundamental to the sustained life of all organisms. Here, we used the "stable isotope labeling with amino acids in cell culture" (SILAC) approach to explore normal protein turnover and tissue regeneration in adult zebrafish. The ratio of labeled and unlabeled proteins/peptides in specific organs of zebrafish fed a SILAC diet containing (13)C(6)-labeled lysine was determined by liquid chromatography and tandem mass spectrometry. Labeling was highest in tissues with high regenerative capacity, including intestine, liver, and fin, whereas brain and heart displayed the lowest labeling. Proteins with high degree of labeling were mainly involved in catalytic or transport activity pathways. The technique also verified increased protein synthesis during regeneration of the caudal fin following amputation. This newly developed SILAC zebrafish model constitutes a novel tool to analyze tissue regeneration in an animal model amenable to genetic and pharmacologic manipulation.
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