| 1. |
- Datry, T., et al.
(författare)
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A global analysis of terrestrial plant litter dynamics in non-perennial waterways
- 2018
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Ingår i: Nature Geoscience. - : Nature Publishing Group. - 1752-0894 .- 1752-0908. ; 11:7, s. 497-503
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Tidskriftsartikel (refereegranskat)abstract
- Perennial rivers and streams make a disproportionate contribution to global carbon (C) cycling. However, the contribution of intermittent rivers and ephemeral streams (IRES), which sometimes cease to flow and can dry completely, is largely ignored although they represent over half the global river network. Substantial amounts of terrestrial plant litter (TPL) accumulate in dry riverbeds and, upon rewetting, this material can undergo rapid microbial processing. We present the results of a global research collaboration that collected and analysed TPL from 212 dry riverbeds across major environmental gradients and climate zones. We assessed litter decomposability by quantifying the litter carbon-to-nitrogen ratio and oxygen (O2) consumption in standardized assays and estimated the potential short-term CO2 emissions during rewetting events. Aridity, cover of riparian vegetation, channel width and dry-phase duration explained most variability in the quantity and decomposability of plant litter in IRES. Our estimates indicate that a single pulse of CO2 emission upon litter rewetting contributes up to 10% of the daily CO2 emission from perennial rivers and stream, particularly in temperate climates. This indicates that the contributions of IRES should be included in global C-cycling assessments.
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| 2. |
- von Schiller, D., et al.
(författare)
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Sediment Respiration Pulses in Intermittent Rivers and Ephemeral Streams
- 2019
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Ingår i: Global Biogeochemical Cycles. - : American Geophysical Union (AGU). - 0886-6236 .- 1944-9224. ; 33:10, s. 1251-1263
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Tidskriftsartikel (refereegranskat)abstract
- Intermittent rivers and ephemeral streams (IRES) may represent over half the global stream network, but their contribution to respiration and carbon dioxide (CO2) emissions is largely undetermined. In particular, little is known about the variability and drivers of respiration in IRES sediments upon rewetting, which could result in large pulses of CO2. We present a global study examining sediments from 200 dry IRES reaches spanning multiple biomes. Results from standardized assays show that mean respiration increased 32-fold to 66-fold upon sediment rewetting. Structural equation modeling indicates that this response was driven by sediment texture and organic matter quantity and quality, which, in turn, were influenced by climate, land use, and riparian plant cover. Our estimates suggest that respiration pulses resulting from rewetting of IRES sediments could contribute significantly to annual CO2 emissions from the global stream network, with a single respiration pulse potentially increasing emission by 0.2-0.7%. As the spatial and temporal extent of IRES increases globally, our results highlight the importance of recognizing the influence of wetting-drying cycles on respiration and CO2 emissions in stream networks.
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| 3. |
- Uy, G. L., et al.
(författare)
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Contribution of chemotherapy mobilization to disease control in multiple myeloma treated with autologous hematopoietic cell transplantation
- 2015
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Ingår i: Bone Marrow Transplantation. - : Springer Science and Business Media LLC. - 0268-3369 .- 1476-5365. ; 50:12, s. 1513-1518
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Tidskriftsartikel (refereegranskat)abstract
- In patients with multiple myeloma (MM) undergoing autologous hematopoietic cell transplantation (auto-HCT), peripheral blood progenitor cells may be collected following mobilization with growth factor alone (GF) or cytotoxic chemotherapy plus GF (CC+GF). It is uncertain whether the method of mobilization affects post-transplant outcomes. We compared these mobilization strategies in a retrospective analysis of 968 patients with MM from the Center for International Blood and Marrow Transplant Research database who received an auto-Ha in the US and Canada between 2007 and 2012. The kinetics of neutrophil engraftment (>= 0.5 x 10(9)/L) was similar between groups (13 vs 13 days, P=0.69) while platelet engraftment (>= 20 x 10(9)/L) was slightly faster with CC+GF (19 vs 18 days, P=0.006). Adjusted 3-year PFS was 43% (95% confidence interval (CI) 38-48) in GF and 40% (95% CI 35-45) in CC+GF, P=0.33. Adjusted 3-year OS was 82% (95% CI 78-86) vs 80% (95% CI 75-84), P=0.43 and adjusted 5-year OS was 62% (95% CI 54-68) vs 60% (95% CI 52-67), P=0.76, for GF and CC+GF, respectively. We conclude that MM patients undergoing auto-Ha have similar outcomes irrespective of the method of mobilization and found no evidence that the addition of chemotherapy to mobilization contributes to disease control.
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| 4. |
- Catalan, N., et al.
(författare)
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Biodegradation kinetics of dissolved organic matter chromatographic fractions in an intermittent river
- 2017
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Ingår i: Journal of Geophysical Research - Biogeosciences. - : AMER GEOPHYSICAL UNION. - 2169-8953 .- 2169-8961. ; 122:1, s. 131-144
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Tidskriftsartikel (refereegranskat)abstract
- Controls on the degradation of dissolved organic matter (DOM) are complex but key to understand the role of freshwaters in the carbon cycle. Both the origin and previous degradation history have been suggested to determine DOM reactivity, but it is still a major challenge to understand the links between DOM composition and biodegradation kinetics. An appropriate context to study these links are intermittent rivers, as summer drought naturally diversifies DOM sources and sinks. Here we investigated the biodegradation kinetics of DOM in the main aquatic environments present in a temporary river. During dark incubations we traced the dynamics of bulk DOM and its main chromatographic fractions defined using LC-OCD: high molecular weight substances (HMWS), low molecular weight substances (LMWS), and humic substances and building blocks. Bulk DOM decay patterns were successfully fitted to the reactivity continuum (RC) biodegradation model. The RC parameters depicted running waters as the sites presenting a more reactive DOM, and temporary pools, enriched in leaf litter, as the ones with slowest DOM decay. The decay patterns of each DOM fraction were consistent throughout sites. LMWS and HMWS decayed in all cases and could be modeled using the RC model. Notably, the dynamics of LMWS controlled the bulk DOM kinetics. We discuss the mechanistic basis for the chromatographic fractions' kinetics during biodegradation and the implications that preconditioning and summer drought can have for DOM biodegradation in intermittent rivers.
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| 5. |
- Gu, Y, et al.
(författare)
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Quick Hot Shot & Young Surgeon Presentation
- 2015
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Ingår i: Hernia : the journal of hernias and abdominal wall surgery. - 1248-9204. ; 19 Suppl 1, s. S77-84
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Tidskriftsartikel (refereegranskat)
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| 6. |
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| 7. |
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| 8. |
- Saji, N. S., et al.
(författare)
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Hadean geodynamics inferred from time-varying 142Nd/144Nd in the early Earth rock record
- 2018
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Ingår i: Geochemical Perspectives Letters. ; 7, s. 43-48
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Tidskriftsartikel (refereegranskat)abstract
- Tracking the secular evolution of 142Nd/144Nd anomalies is important towards understanding the crust-mantle dynamics in the early Earth. Excessive scatter in the published data, however, precludes identifying the fine structure of 142Nd/144Nd evolution as the expected variability is on the order of few parts per million. We report ultra-high precision 142Nd/144Nd data for Eoarchean and Palaeoarchean rocks from the Isua Supracrustal Belt (SW Greenland) that show a well-resolved 142Nd/144Nd temporal variability suggesting progressive convective homogenisation of the Hadean Isua depleted mantle. This temporally decreasing 142Nd/144Nd signal provides a direct measure of early mantle dynamics, defining a stirring timescale of <250 Myr consistent with vigorous convective stirring in the early mantle. The 142Nd/144Nd evolution suggests protracted crustal residence times of ~1000-2000 Myr, inconsistent with modern-style plate tectonics in the Archean. In contrast, a stagnant-lid regime punctuated by episodes of mantle overturns accounts for the long life-time estimated here for the Hadean proto-crust.
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| 9. |
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| 10. |
- Zibra, Ivan, et al.
(författare)
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Tectono-magmatic evolution of the Neoarchean Yalgoo dome (Yilgarn Craton): Diapirism in a pre-orogenic setting
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Gneiss domes occur in any orogenic and anorogenic domain of the continental crust, from Precambrian cratons to present-day active orogens. They commonly contain a core of granitic rocks and/or high-grade metamorphic rocks, overlain by a mantle of lower-grade rocks. Evolutionary models of many gneiss domes are controversial. We use new structural and geochronological data to constrain the tectono-magmatic evolution of the Yalgoo dome in the Yilgarn Craton of Western Australia. The granite–migmatite core of the dome shows an overall domal foliation pattern, associated with radial and outwardsplunging lineations. A high-strain zone with top-outwards sense of shear (the Badja decollément) occurs along the granite–greenstone boundary. The greenstone sequence contains an angular unconformity that likely developed during doming. We show that doming, associated with outward flow of supracrustal material, was accompanied by the emplacement of large volumes of granitic magma at 2760–2750 Ma. The dome-scale finite strain pattern resulted from diapiric granite emplacement into the greenstone cover, with negligible background regional stress. Granitic plutons flanking the Yalgoo dome show a similar, first-order structural architecture. The dome-forming fabric is locally overprinted by a discordant, north-trending foliation caused by folding that likely developed at c. 2700 Ma, during the Neoarchean Yilgarn orogeny.
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