Multivariate Exploratory Analysis of the Bulgarian Soil Quality Monitoring Network.

The goal of the present study is to assess the soil quality in Bulgaria using (i) an appropriate set of soil quality indicators, namely primary nutrients (C, N, P), acidity (pH), physical clay content and potentially toxic elements (PTEs: Cu, Zn, Cd, Pb, Ni, Cr, As, Hg) and (ii) respective data mining and modeling using chemometrical and geostatistical methods. It has been shown that five latent factors are responsible for the explanation of nearly 70% of the total variance of the data set available (principal components analysis) and each factor is identified in terms of its contribution to the formation of the overall soil quality-the mountain soil factor, the geogenic factor, the ore deposit factor, the low nutrition factor, and the mercury-specific factor. The obtained soil quality patterns were additionally confirmed via hierarchical cluster analysis.

Impact of Chitosan on Water Stability and Wettability of Soils.

Chitosan has become increasingly applied in agriculture worldwide, thus entering the soil environment. We hypothesized that chitosan should affect the water stability of soil. Since this problem has not been studied to date, we examined, for the first time, the influence of chitosan on the water stability and wettability of soil aggregates.

Establishment of geochemical background and threshold values for 8 potential toxic elements in the Bulgarian soil quality monitoring network.

Establishment of geochemical background and threshold values of potentially toxic elements is essential for soil management activities. Available topsoil data collected in the Bulgarian soil quality monitoring network are explored for the concentrations of the potentially toxic elements (PTEs) of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn. The 'median + 2MAD' and TIF methods for obtaining geochemical threshold values, which differentiate sampling sites with background from those with unusually high element concentrations, are presented.

Metabotrophic potential of neurotrophins:implication in obesity and related diseases?

In addition to their stimulatory action on neuronal differentiation and survival, the neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) improve glucose and lipid metabolism and control energy balance and feeding behavior. These latter activities are referred to here as the metabotrophic potential of neurotrophins. We recently reported that circulating NGF and BDNF levels are reduced in the metabolic syndrome and in acute coronary syndromes, and that the tissue content of NGF is reduced in atherosclerotic coronary arteries.