| 1. |
|
|
| 2. |
- Fenn, Kaja, et al.
(författare)
-
Insights into the provenance of the Chinese Loess Plateau from joint zircon U-Pb and garnet geochemical analysis of last glacial loess
- 2018
-
Ingår i: Quaternary Research. - : Cambridge University Press (CUP). - 0033-5894 .- 1096-0287. ; 89:3, s. 645-659
-
Tidskriftsartikel (refereegranskat)abstract
- The Chinese Loess Plateau, the world's largest and oldest loess record, preserves evidence of Asia's long-term dust source dynamics, but there is uncertainty over the source of the deposits. Recent single-grain detrital zircon U-Pb age analysis has progressed this issue, but debates remain about source changes, and the generation and interpretation of zircon data. To address this, we analyze different groupings of new and existing datasets from the Loess Plateau and potential sources. We also present the results of a first high resolution sampling, multi-proxy provenance analysis of Beiguoyuan loess using U-Pb dating of detrital zircons and detrital garnet geochemistry. The data shows that some small source differences seem to exist between different areas on the Loess Plateau. However, sediment source appears to be unchanging between loess and palaeosols, supporting a recent material recycling hypothesis. Our zircon and garnet data demonstrates, however, that Beiguoyuan experienced a temporary, abrupt source shift during the last glacial maximum, implying that local dust sources became periodically active during the Quaternary. Our results highlight that grouping data to achieve bigger datasets could cause identification of misleading trends. Additionally, we suggest that multi-proxy single-grain approaches are required to gain further insight into Chinese Loess Plateau dust sources.
|
|
| 3. |
- Ferrero, Luca, et al.
(författare)
-
Airborne and marine microplastics from an oceanographic survey at the Baltic Sea : An emerging role of air-sea interaction?
- 2022
-
Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 824
-
Tidskriftsartikel (refereegranskat)abstract
- Microplastics (MPs) pollution is one of the most important problems of the Earth. They have been found in all the natural environments, including oceans and the atmosphere. In this study, the concentrations of both atmospheric and marine MPs were measured over the Baltic along a research cruise that started in the Gdansk harbour, till the Gotland island, and the way back. A deposition box (based on a combination of active/passive sampling) was used to collect airborne MPs while, marine MPs concentrations were investigated during the cruise using a dedicated net. Ancillary data were obtained using a combination of particle counters (OPC, LAS and CPC), Aethalometer (AE33 Magee Scientific), spectrofluorometer (sea surface samples, Varian Cary Eclipse), and meteorological sensors. Results showed airborne microplastics average concentrations higher in the Gdansk harbour (161 ± 75 m−3) compared to the open Baltic Sea and to the Gotland island (24 ± 9 and 45 ± 20 m−3). These latter values are closer to the ones measured in the sea (79 ± 18 m−3). The MPs composition was investigated using μ-Raman (for the airborne ones) and FTIR (for marine ones); similar results (e.g. polyethylene, polyethylene terephthalates, polyurethane) were found in the two environmental compartments. The concentrations and similar composition in air and sea suggested a linkage between the two compartments. For this purpose, the atmospheric MPs' equivalent aerodynamic diameter was calculated (28 ± 3 μm) first showing the capability of atmospheric MPs to remain suspended in the air. At the same time, the computed turnover times (0.3–90 h; depending on MPs size) limited the transport distance range. The estimated MPs sea emission fluxes (4–18 ∗ 106 μm3 m−2 s−1 range) finally showed the contemporary presence of atmospheric transport together with a continuous emission from the sea surface enabling a grasshopper long-range transport of microplastics across the sea.
|
|
| 4. |
- Landi, Antonio, et al.
(författare)
-
Transient vs In-Hospital Persistent AcuteKidney Injury in Patients With Acute Coronary Syndrome.
- 2023
-
Ingår i: JACC. Cardiovascular interventions. - : Elsevier BV. - 1876-7605 .- 1936-8798. ; 16:2, s. 193-205
-
Tidskriftsartikel (refereegranskat)abstract
- The occurrence of acute kidney injury (AKI) among patients with acute coronary syndrome (ACS) undergoing invasive management is associated with worse outcomes. However, the prognostic implications of transient or in-hospital persistent AKI may differ.The aim of this study was to evaluate the prognostic implications of transient or in-hospital persistent AKI in patients with ACS.In the MATRIX (Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of Angiox) trial, 203 subjects were excluded because of incomplete information or end-stage renal disease, with a study population of 8,201 patients. Transient and persistent AKI were defined as renal dysfunction no longer or still fulfilling the AKI criteria (>0.5mg/dL or a relative >25% increase in creatinine) at discharge, respectively. Thirty-day coprimary outcomes were the out-of-hospital composite of death, myocardial infarction, or stroke (major adverse cardiovascular events [MACE]) and net adverse cardiovascular events (NACE), defined as the composite of MACE or Bleeding Academic Research Consortium type 3 or 5 bleeding.Persistent and transient AKI occurred in 750 (9.1%) and 587 (7.2%) subjects, respectively. After multivariable adjustment, compared with patients without AKI, the risk for 30-day coprimary outcomes was higher in patients with persistent AKI (MACE: adjusted HR: 2.32; 95%CI: 1.48-3.64; P< 0.001; NACE: adjusted HR: 2.29; 95%CI: 1.48-3.52; P< 0.001), driven mainly by all-cause mortality (adjusted HR: 3.43; 95%CI: 2.03-5.82; P< 0.001), whereas transient AKI was not associated with higher rates of MACE or NACE. Results remained consistent when implementing the KDIGO (Kidney Disease Improving Global Outcomes) criteria.Among patients with ACS undergoing invasive management, in-hospital persistent but not transient AKI was associated with higher risk for 30-day MACE and NACE. (Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of Angiox [MATRIX]; NCT01433627).
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Nie, Junsheng, et al.
(författare)
-
Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment
- 2015
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river/'s upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records.
|
|
| 8. |
- Rittner, Martin, et al.
(författare)
-
The provenance of Taklamakan desert sand
- 2016
-
Ingår i: Earth and Planetary Science Letters. - : Elsevier BV. - 0012-821X .- 1385-013X. ; 437, s. 127-137
-
Tidskriftsartikel (refereegranskat)abstract
- Sand migration in the vast Taklamakan desert within the Tarim Basin (Xinjiang Uyghur Autonomous region, PR China) is governed by two competing transport agents: wind and water, which work in diametrically opposed directions. Net aeolian transport is from northeast to south, while fluvial transport occurs from the south to the north and then west to east at the northern rim, due to a gradual northward slope of the underlying topography. We here present the first comprehensive provenance study of Taklamakan desert sand with the aim to characterise the interplay of these two transport mechanisms and their roles in the formation of the sand sea, and to consider the potential of the Tarim Basin as a contributing source to the Chinese Loess Plateau (CLP). Our dataset comprises 39 aeolian and fluvial samples, which were characterised by detrital-zircon U-Pb geochronology, heavy-mineral, and bulk-petrography analyses. Although the inter-sample differences of all three datasets are subtle, a multivariate statistical analysis using multidimensional scaling (MDS) clearly shows that Tarim desert sand is most similar in composition to rivers draining the Kunlun Shan (south) and the Pamirs (west), and is distinctly different from sediment sources in the Tian Shan (north). A small set of samples from the Junggar Basin (north of the Tian Shan) yields different detrital compositions and age spectra than anywhere in the Tarim Basin, indicating that aeolian sediment exchange between the two basins is minimal. Although river transport dominates delivery of sand into the Tarim Basin, wind remobilises and reworks the sediment in the central sand sea. Characteristic signatures of main rivers can be traced from entrance into the basin to the terminus of the Tarim River, and those crossing the desert from the south to north can seasonally bypass sediment through the sand sea. Smaller ephemeral rivers from the Kunlun Shan end in the desert and discharge their sediment there. Both river run-off and wind intensity are strongly seasonal, their respective transport strength and opposing directions maintain the Taklamakan in its position and topography.
|
|
| 9. |
- Yang, Jin, et al.
(författare)
-
Climatic Forcing of Plio-Pleistocene Formation of the Modern Limpopo River, South Africa
- 2021
-
Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 48:14
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the evolution of river systems in southern Africa is fundamental to constrain the evolution of landscape and sediment dispersal patterns. It is widely considered that the upper Zambezi River was connected with the Limpopo River during the Cretaceous, forming what was then the largest river in Africa. Crustal flexure during the Paleogene severed the upper Zambezi drainage from the Limpopo, setting the framework of the modern Zambezi and Limpopo River systems. We present first evidence-based on heavy-mineral assemblages from cores drilled offshore of the Limpopo River mouth and samples collected in different reaches of the modern Limpopo River, integrated with magnetic susceptibility, detrital-zircon geochronology, and geomorphological analysis-suggesting that the current Limpopo River formed recently in the Plio-Quaternary. Plio-Quaternary climate change is envisaged to have controlled the recent dynamics of river drainage and consequent distribution of sediment loads, as observed in many other transcontinental rivers worldwide.
|
|
