6 research outputs found
Multi‐proxy reconstruction of the Holocene vegetation and land use dynamics in the Julian Alps, north‐west Slovenia
International audienceSmall mountain lakes are natural archives for understanding long-term natural and anthropogenic impact on the environment. This study focused on long-term (last ca. 13 000 years) vegetation changes and sedimentary processes in the catchment area of Lake Planina pri jezeru (1430 m a.s.l.) by using mineralogical, geochemical and palynological methods. Palynological results suggest that regional vegetation between 12 900 and 11 700 cal a BP was a herbaceous-forest tundra (Pinus, Artemisia, Poaceae). Climate warming at the beginning of the Holocene (ca. 11 700 cal a BP) caused the transition from a wetland (Cyperaceae) to an eutrophic lake with alternating anoxic (pyrite) and oxic conditions (gypsum). In addition, the surrounding area became forested (Picea, Larix, Ulmus). Fagus expanded at 10 200 cal a BP and Abies at 8200 cal a BP. Between 7500 and 4300 cal a BP, human impact on the environment was barely noticeable and mostly limited to grazing. During 4300-430 cal a BP human impact became more evident and gradually increased. The greatest influence was observed from 430 cal a BP onwards, when excessive exploitation of the surrounding area (logging and grazing) severely eutrophicated the lake
Contaminant uptake in wastewater irrigated tomatoes
As population growth and climate change add to the problem of water scarcity in many regions, the argument for using treated wastewater for irrigation is becoming increasingly compelling, which makes understanding the risks associated with the uptake of harmful chemicals by crops crucial. In this study, the uptake of 14 chemicals of emerging concern (CECs) and 27 potentially toxic elements (PTEs) was studied in tomatoes grown in soil-less (hydroponically) and soil (lysimeters) media irrigated with potable and treated wastewater using LC-MS/MS and ICP-MS. Bisphenol S, 2,4 bisphenol F, and naproxen were detected in fruits irrigated with spiked potable water and wastewater under both conditions, with BPS having the highest concentration (0.034–0.134 µg kg f. w.). The levels of all three compounds were statistically more significant in tomatoes grown hydroponically (<LOQ - 0.137 µg kg f. w.) than in soil (<LOQ - 0.083 µg kg f. w.). Their elemental composition shows differences between tomatoes grown hydroponically or in soil and tomatoes irrigated with wastewater and potable water. Contaminants at determined levels showed low dietary chronic exposure. When the health-based guidance values for the studied CECs are determined, results from this study will be helpful for risk assessors
Size-dependent effects of gold nanoparticles uptake on maturation and antitumor functions of human dendritic cells in vitro
Gold nanoparticles (GNPs) are claimed as outstanding biomedical tools for cancer diagnostics and photo-thermal therapy, but without enough evidence on their potentially adverse immunological effects. Using a model of human dendritic cells (DCs), we showed that 10 nm- and 50 nm-sized GNPs (GNP10 and GNP50, respectively) were internalized predominantly via dynamin-dependent mechanisms, and they both impaired LPS-induced maturation and allostimulatory capacity of DCs, although the effect of GNP10 was more prominent. However, GNP10 inhibited LPS-induced production of IL-12p70 by DCs, and potentiated their Th2 polarization capacity, while GNP50 promoted Th17 polarization. Such effects of GNP10 correlated with a stronger inhibition of LPS-induced changes in Ca2+ oscillations, their higher number per DC, and more frequent extraendosomal localization, as judged by live-cell imaging, proton, and electron microscopy, respectively. Even when released from heat-killed necrotic HEp-2 cells, GNP10 inhibited the necrotic tumor cell-induced maturation and functions of DCs, potentiated their Th2/Th17 polarization capacity, and thus, impaired the DCs% capacity to induce T cell-mediated anti-tumor cytotoxicity in vitro. Therefore, GNP10 could potentially induce more adverse DC-mediated immunological effects, compared to GNP50