Time since deglaciation and geomorphological disturbances determine the patterns of geochemical, mineralogical and microbial successions in an Icelandic foreland
GEODERMA
Authors: Wojcik, Robin; Donhauser, Johanna; Frey, Beat; Benning, Liane G.
Abstract
Glacier forelands are an ideal natural laboratory to study the initial stages of pedogenesis. Here, we document a build-up in organic carbon (C), nitrogen (N) and phosphorous (P), an increase in bacterial communities as well as a progression of physical and chemical weathering along a similar to 2 km long and 122 yr old chronosequence in the glacier foreland of Flaajokull in south-eastern Iceland. We complemented this chronosequence dataset with an assessment of the variability in soils that were affected by geomorphological disturbances along a 175-m long toposequence transect. While soils at the crest of the toposequence moraines were anomalously under-developed due to frequent erosion, the soils at the footslopes were characterized by a more advanced successional stage in that they benefited from an ample supply of nutrients, fine and more weathered materials as well as higher moisture. The large variability in soil properties across the toposequence demonstrates that, even across short distances, disturbances driven by hillslope and glacio-fluvial processes can lead to substantial heterogeneities in soil development in glacier forelands. We emphasize that the geochemical and biological features of soil development and patterns of succession in glacier forelands should be interpreted as the result of both changes in time since deglaciation and geomorphological disturbances.
Flavonoid-rich fraction attenuates permethrin-induced toxicity by modulating ROS-mediated hepatic oxidative stress and mitochondrial dysfunction ex vivo and in vivo in rat
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
Authors: Aoiadni, Nissaf; Ayadi, Houda; Jdidi, Hajer; Naifar, Manel; Maalej, Sami; Makni, Fatma Ayadi; El Feki, Abdelfattah; Fetoui, Hamadi; Koubaa, Fatma Ghorbel
Abstract
The present study explores the antioxidant, anti-microbial, and hepatoprotective potentials of flavonoid-rich fractions from Fumaria officinalis against permethrin-induced liver damage ex vivo/in vivo in rat. However, HPLC-DAD analysis revealed the richness of 6 components in ethyl acetate fraction (EAF) where ferulic acid, rosmarinic acid, and myricetin are the most abundant. The in vitro assays showed that EAFs have impressive antioxidant and anti-microbial properties. Ex vivo, permethrin (PER) (100 mu M) induced a decrease of hepatic AST and ALT activities and 25-OH vitamin D and vitamin C levels and an increase of ALP and LDH activities, TBARS, and gamma-GT levels with a disturbance of oxidative status. The hepatoprotective effect of EAF (1 mg/mL) against PER was confirmed by the amelioration of oxidative stress profile. In vivo, permethrin was found to increase absolute and relative liver weights, plasma transaminase activities, lactate-to-pyruvate ratio, hepatic and mitochondrial lipid peroxidation, and protein oxidation levels. This pesticide triggered a decrease of Ca2+ and Mg2+-ATPases and mitochondrial enzyme activities. The co-treatment with EAF reestablished the hepatic and mitochondrial function, which could be attributed to its richness in phenolic compounds.