The effects of leaching from alkaline red mud on soil biota: modelling the conditions after the Hungarian red mud disaster

A soil column experiment was set up to investigate the effect of red mud from Ajka (Hungary) on a typical soil profile from the concerned area. The chemical changes caused by the leachate of the red mud and the effects of these changes on living organisms were assessed. Ecotoxicological tests with Vibrio fischeri, Sinapis alba and Folsomia candida were performed and the number of aerobic heterotrophic microorganisms was determined. The total, plant available, exchangeable and water soluble fractions of Na, Mo, Cu, and Cr increased in the soil mostly due to their leaching from the red mud layer and partly to the increase of the pH and DOC concentration. The chemical changes had significant effects on the test organisms only in the 0 – 30 cm soil layer except for F. candida that had a lower survival rate also in the 30 – 50 cm soil layer. There were no severe toxic effects detected on the test organisms. Furthermore in case of the aerobic heterotrophic cell number and S. alba germination a stimulating effect was revealed. However, the red mud itself was toxic, therefore the performed ecotoxicology tests have justified the removal of red mud from the soil surface after the disaster

Efficient direct 2,2,2-trifluoroethylation of indoles via C-H functionalization

A novel highly C3 selective metal free trifluoroethylation of indoles using 2,2,2-trifuoroethyl(mesityl)-iodonium triflate was developed. The methodology enables the introduction of a trifluoroethyl group in a fast and efficient reaction under mild conditions with high functional group tolerance. Beyond the synthetic developments, quantum chemical calculations provide a deeper understanding of the transformation. This journal i

Factor analysis of Hungarian hydrophysical data to predict soil water retention characteristics

We explore the information associated with soil water retention included in the large scale soil maps of Hungary. We employed factor analysis to investigate tire role of different commonly measured soil properties - namely -,and and clay content, organic matter content, pH and CaCO3 content - on determining soil water retention at different pF values (pF0, pF2.5, pF4.2 and pF6.2). Analyses were performed oil all the samples of the database, that contains 382 1 soil horizons of diverse soil types, as well as a selection of the horizons belonging to Chernozem soils of the database. Results show considerable differences of water retention characteristics of Chernozems, mainly at pF0. This suggests that a separate analysis for different soil types might be appropriate in order to characterize the impact of measured soil properties on water retention

Grouping of soils according to their soil water retention characteristics

Soil water retention capacity is usually estimated by pedotransfer functions which, in turn, are very problematic to apply for soil maps containing only categorical-type soil properties. Most of the soil information in Hungary is available in the format of soil maps reporting categorical-type information and often lacking data about measured hydrophysical properties. Here we are mainly concerned with the possibility of providing predictions of soil water retention categories starting from continuous- and/or categorical- type information. First we used Factor Analysis (FA) to synthesize the information contained in the soil variables. We then employed the factors extracted in the context of cluster analysis (CA) to differentiate soil groups that can be characterized by means of typical soil water retention values. Finally, we used multinomial logistic regression to address the relationship between the soil water content and the other soil properties used in FA

Inflammatory response of endothelial cells to a human endogenous retrovirus associated with multiple sclerosis is mediated by TLR4.

The MSRV (multiple sclerosis-associated retrovirus) belongs to the human endogenous retrovirus HERV-W family. The envelope protein originating from the MSRV has been found in most patients with multiple sclerosis (MS). This protein (Env-ms) has pro-inflammatory properties for several types of immune cells and could therefore play a role in MS pathogenesis by promoting the leukocyte diapedesis observed in the central nervous system of patients. Our study aims to analyze the effects of Env-ms on the blood-brain barrier (BBB) at a molecular and functional level. We demonstrate that the recombinant MSRV envelope is able to stimulate several inflammatory parameters in a human BBB in vitro model, the HCMEC/D3 brain endothelial cell line. Indeed, Env-ms induces over-expression of ICAM-1, a major mediator of leukocyte adhesion to endothelial cells, in a dose-dependent manner as well as a strong dose-dependent production of the pro-inflammatory cytokines IL-6 and IL-8. Furthermore, using a silencing approach with siRNAs, we show that Env-ms is recognized via the Toll-like receptor 4 receptor, a pattern recognition receptor of innate immunity present on endothelial cells. We also show, using functional assays, that treatment of brain endothelial cells with Env-ms significantly stimulated the adhesion and the transmigration of activated immune cells through a monolayer of endothelial cells. These findings support the hypothesis that MSRV could be involved in the pathogenesis of MS disease or at least in maintenance of inflammatory conditions, thus fueling the auto-immune disorder. MSRV could also play a role in other chronic inflammatory diseases

The 1:1 resonance in Extrasolar Systems: Migration from planetary to satellite orbits

We present families of symmetric and asymmetric periodic orbits at the 1/1 resonance, for a planetary system consisting of a star and two small bodies, in comparison to the star, moving in the same plane under their mutual gravitational attraction. The stable 1/1 resonant periodic orbits belong to a family which has a planetary branch, with the two planets moving in nearly Keplerian orbits with non zero eccentricities and a satellite branch, where the gravitational interaction between the two planets dominates the attraction from the star and the two planets form a close binary which revolves around the star. The stability regions around periodic orbits along the family are studied. Next, we study the dynamical evolution in time of a planetary system with two planets which is initially trapped in a stable 1/1 resonant periodic motion, when a drag force is included in the system. We prove that if we start with a 1/1 resonant planetary system with large eccentricities, the system migrates, due to the drag force, {\it along the family of periodic orbits} and is finally trapped in a satellite orbit. This, in principle, provides a mechanism for the generation of a satellite system: we start with a planetary system and the final stage is a system where the two small bodies form a close binary whose center of mass revolves around the star.Comment: to appear in Cel.Mech.Dyn.Ast