Total phosphorus (P) river inputs and lake concentrations for the Neagh system in Northern Ireland are compared from the period 1974-1997. The main routes of P transfer between the lake water and the sediment are settlement of abiotic particles and planktonic diatoms, summer sediment release and re-sedimentation in the last months of the year. The annual river loading to the lake varied between 0.7 and 1.8 g P m(-2), and sediment release can be as much as 1.4 g P m(-2). A simple model evaluated the effect of sediment-water exchanges on the phosphorus available for spring phytoplankton growth. It showed that re-sedimentation of released P and washout over the winter greatly mitigated its effect. Correlation analysis demonstrated that the very large summer releases of sediment P were not related directly to the spring inputs from diatom settlement. No long-term trends in P release were seen.
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http://dx.doi.org/10.1016/s0045-6535(00)00128-4 | DOI Listing |
This study concerns the U/U ratios in environmental samples collected in the Pamir region (Central Asia). Cryoconite (a supra-glacial sediment), soil and river water were sampled in the Muztagh Ata Glacier Basin, a secondary basin belonging to Gaizi River watershed. The aim of the research is to assess the impact of anthropic nuclear activities in such a remote area, being the U/U ratio highly sensitive to anthropogenic disturbances.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESP), Beijing, China; Key Laboratory for Emerging Organic Contaminants Control (BKLEOC), Beijing, China; Laboratory for Environmental Frontier Technologies (BLEFT), School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:
Widespread detection in soils and sediments underscores the potential threats posed by persistent, bioaccumulative and toxic perfluorooctane sulfonate (PFOS) to ecosystems and organisms. Nevertheless, the formidable energy of the C-F bond imparts stability and hampers degradation. This study investigates the potential of boron carbide (BC), a hard-ceramic material often utilized in armor and abrasion contexts, for degrading solid-phase PFOS through ball milling.
View Article and Find Full Text PDFHIV-1 assembly is initiated by the binding of Gag polyproteins to the inner leaflet of the plasma membrane, mediated by the myristylated matrix (MA) domain of Gag. Subsequent to membrane binding, Gag oligomerizes and buds as an immature, non-infectious virus particle, which, upon cleavage of the Gag precursor by the viral protease, transforms into a mature, infectious virion. During maturation, the MA lattice underlying the viral membrane undergoes a structural rearrangement and the newly released capsid (CA) protein forms a mature capsid that encloses the viral genome.
View Article and Find Full Text PDFFEMS Microbiol Ecol
January 2025
Center for Pan-third Pole Environment, Lanzhou University, Lanzhou, China.
In polar and alpine regions, global warming and landform changes are draining lakes, transforming them into permafrost with altered microbial communities and element cycling. In this study, we investigated bacterial and archaeal (prokaryotic) community changes in the newly exposed sediment of Zonag Lake (Tibetan Plateau), focusing on prokaryotic diversity, community structure, and genes involved in carbon fixation and nitrogen cycling across lateral (up to 800 m) and vertical (up to 80 cm) horizons. The results showed that prokaryotic richness decreased across the lateral horizons, coinciding with reductions in carbon concentrations.
View Article and Find Full Text PDFEnviron Res
January 2025
Jiangsu Water Conservancy Construction Engineering co.,ltd, Yangzhou, P. R. China.
Biochar is one of the ways for carbon storage, pollution control and biosolid reuse. Aquatic plant reeds are widely used in nutrient removal in wetlands and have huge biomass. Nonetheless, little is known regarding the effects of reed-based biochar on sediments.
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