Search results for "Precipitation"
showing 10 items of 826 documents
Nitrous oxide fluxes from permafrost regions
2020
This dataset is a synthesis of published nitrous oxide (N2O) fluxes from permafrost-affected soils in Arctic, Antarctic, and Alpine permafrost regions. The data includes mean N2O flux rates measured under field (in situ) conditions and in intact plant-soil systems (mesocosms) under near-field conditions. The dataset further includes explanatory environmental parameters such as meteorological data, soil physical-chemical properties, as well as site and experimental information. Data has been synthesized from published studies (see 'Further details'), and in some cases the authors of published studies have been contacted for additional site-level information. The dataset includes studies publ…
The influence of climate change on the soil organic carbon content in Italy from 1961 to 2008
2011
Abstract Soils are the biggest carbon store in the world (1500 Gt, e.g. 1.5 × 10 21 g). The European Commission indicates the accounting of soil organic carbon (SOC) variations in space and time as the first step in the strategy for soil protection. It is indeed necessary in evaluating the risk of soil organic matter decline and soil biodiversity decline, and when evaluating the role played by soils in global CO 2 accounting. Previous maps of SOC variations in Italy did not consider the direct effect of climate. There is a marked inter-dependence between SOC and climate. SOC increases with the increase in precipitations and decreases with a rise in temperatures. It is also known that land …
Extraction–Pyrolytic Method for TiO2 Polymorphs Production
2021
The authors thank V. Kuzovkov, A. Lushchik and M. Lushchik for many useful discussions. The research was (partly) performed in the Institute of Solid State Physics, University of Latvia ISSP UL. ISSP UL as the Center of Excellence is supported through the Framework Program for European universities Union Horizon 2020, H2020-WIDESPREAD-01–2016–2017-TeamingPhase2 under Grant Agreement No. 739508, CAMART2 project.
Low Temperature H2S Removal with Metal-Doped Nanostructure ZnO Sorbents: Study of the Origin of Enhanced Reactivity in Cu-Containing Materials
2011
Sulfidation of pure and metal-doped ZnO nanostructure sorbents (M0.03Zn0.97O, M = Fe, Co, Ni, Cu) was studied in order to clarify the effect of metal on the transformation kinetics at 200−350 °C. The solids were prepared by coprecipitation from metal nitrate solution followed by calcination at 400 °C. Reaction with H2S was studied by thermal gravimetric analysis (TGA) using a gas mixture containing 0.2 vol % H2S in equimolar H2−N2. It was found that at 350 °C the TGA sulfidation profiles of all studied samples are similar, with the interface reaction being the main rate-determining step. After lowering the temperature to 250 °C the transformation of Cu0.03Zn0.97O continues to be controlled …
Discovery and validation of small-molecule heat-shock protein 90 inhibitors through multimodality molecular imaging in living subjects.
2012
Up-regulation of the folding machinery of the heat-shock protein 90 (Hsp90) chaperone protein is crucial for cancer progression. The two Hsp90 isoforms (α and β) play different roles in response to chemotherapy. To identify isoform-selective inhibitors of Hsp90(α/β)/cochaperone p23 interactions, we developed a dual-luciferase (Renilla and Firefly) reporter system for high-throughput screening (HTS) and monitoring the efficacy of Hsp90 inhibitors in cell culture and live mice. HTS of a 30,176 small-molecule chemical library in cell culture identified a compound, N -(5-methylisoxazol-3-yl)-2-[4-(thiophen-2-yl)-6-(trifluoromethyl)pyrimidin-2-ylthio]acetamide (CP9), that binds to Hsp90(α/β) an…
In human endothelial cells rapamycin causes mTORC2 inhibition and impairs cell viability and function.
2008
Aim Drug-eluting stents are widely used to prevent restenosis but are associated with late endothelial damage. To understand the basis for this effect, we have studied the consequences of a prolonged incubation with rapamycin on the viability and functions of endothelial cells. Methods and results Human umbilical vein or aorta endothelial cells were exposed to rapamycin in the absence or in the presence of tumour necrosis factor α (TNFα). After a 24 h-incubation, rapamycin (100 nM) caused a significant cell loss associated with the increase of both apoptosis and necrosis, as quantified by propidium iodide staining, caspase 3 activity, and lactate dehydrogenase release. Rapamycin also impair…
α-Synuclein expression levels do not significantly affect proteasome function and expression in mice and stably transfected PC12 cell lines
2004
α-Synuclein (α-syn) is a small protein of unknown function that is found aggregated in Lewy bodies, the histopathological hallmark of sporadic Parkinson disease and other synucleinopathies. Mutations in the α-syn gene and a triplication of its gene locus have been identified in early onset familial Parkinson disease. α-Syn turnover can be mediated by the proteasome pathway. A survey of published data may lead to the suggestion that overexpression of α-syn wild type, and/or their variants (A53T and A30P), may produce a decrease in proteasome activity and function, contributing to α-syn aggregation. To investigate the relationship between synuclein expression and proteasome function we have s…
Phosphorus Loss in Overfertilized Soils: The Selective P Partitioning and Redistribution Between Particle Size Separates
2007
Using 12 well-characterised European soils contrasting in their physical and chemical properties, we demonstrate significant differences in the partitioning of phosphorus (P) between various particle size separates. Samples of each soil were subjected to one of three methods of increasingly aggressive dispersion in the order water (WD), mechanical (MD) or chemical (CD). A general, although not exclusive, inverse relationship existed between the concentration of various attributes (these included organic carbon, oxalate and dithionite iron contents, total P, resin and water extractable P) and particle size. The quantity, composition and physico-chemical properties of individual size separate…
Impact of woody encroachment on soil organic carbon and nitrogen in abandoned agricultural lands along a rainfall gradient in Italy
2011
Land use changes represent one of the most important components of global environmental change andhave a strong influence on carbon cycling. As a consequence of changes in economy during the last century, areas of marginal agriculture have been abandoned leading to secondary successions. The encroachment of woody plants into grasslands, pastures and croplands is generally thought to increase the carbon stored in these ecosystems even though there are evidences for a decrease in soil carbon stocks after land use change. In this paper, we investigate the effects of woody plant invasion on soil carbon and nitrogen stocks along a precipitation gradient (200–2,500 mm) using original data from pa…
Tapered Multiblock Star Copolymers: Synthesis, Selective Hydrogenation, and Properties
2020
Two series of well-defined multiblock four-arm tapered star copolymers with “arms” of the type poly(styrene)-block-poly(isoprene-grad-styrene), (SI/S)₄, were synthesized on a multigram scale with short reaction times. Targeted molecular weight (M) values ranged from 80 to 240 kg mol–¹ with polystyrene (PS) compositions of 40 and 60 wt %. Narrowly distributed (Đ = 1.04–1.12) copolymers were obtained regardless of M and without additional purification beyond precipitation. At sufficiently high M, members of the 40 wt % PS series possessed either a cylindrical or bicontinuous morphology, whereas the 60 wt % PS series yielded lamellae. The star copolymers outperformed their corresponding linear…