25 research outputs found
Features of modern genesis of the Ishim steppe watershed plain soils
The genesis main directions of the Ishim steppe watershed plain soils depending on their economic use (arable land, forest belt, abandoned land) during the 1950s – 2020s were revealed. Within the studied region, soils were diagnosed on lands of different use. It is shown that the regional morphogenetic feature of all watershed plain soils is the tonguing of the humus horizon, which is reflected in their classification status by the allocation of a dark-tonguic subtype of the soils. Differentiation of the agrodarkhumus horizon into two subhorizons under the influence of plane-cutting processing was revealed in the agrozem, prevailing by area. The manifestation of postagrogenic transformation of soils occurring under forest belts and under deposits with herbaceous vegetation is determined. Postagrogenic soils are characterized by a granular structure, higher reserves of humus and total nitrogen in a layer of 0–20 cm compared to agrozems. In the soil of the forest belt, a coarse-humus neo-horizon was formed, which is not typical of steppe soils. The soil under abandoned for a long time grassland has signs of dark humus horizon progradation to a state close to a virgin one. The additional surface moistening of micro-subsidence soils causes them to have a higher humus content and its reserves in the 0–100 cm layer, deeper leaching of carbonates, the formation of a clay-illuvial horizon in the carbonate-free zone and prevents the formation of a gypsum horizon. The groundwater level raising in the modern period, which is a consequence of the mass plowing and functioning of impenetrable protective forest belts in the study area, caused the appearance of neo-hydromorphism in watershed plain soils and the formation of quasi-clay subtypes. The results indicate the regional specificity of the genetic properties of the Ishim steppe watershed plain soils that distinguish them from their European counterparts, as well as the influence of agrogenic transformation as an anthropogenic factor on them. This influence is reflected in the morphology of soils, their humus state, the nature of the carbonate and gypsum profiles, the processes of halogenesis in them and the variety of salt profiles
Dissecting cause and effect in host-microbiome interactions using the combined worm-bug model system
High-throughput molecular studies are greatly advancing our knowledge of the human microbiome and its specific role in governing health and disease states. A myriad of ongoing studies aim at identifying links between microbial community disequilibria (dysbiosis) and human diseases. However, due to the inherent complexity and heterogeneity of the human microbiome we need robust experimental models that allow the systematic manipulation of variables to test the multitude of hypotheses arisen from large-scale ‘meta-omic’ projects. The nematode C. elegans combined with bacterial models offers an avenue to dissect cause and effect in host-microbiome interactions. This combined model allows the genetic manipulation of both host and microbial genetics and the use of a variety of tools, to identify pathways affecting host health. A number of recent high impact studies have used C. elegans to identify microbial pathways affecting ageing and longevity, demonstrating the power of the combined C. elegans-bacterial model. Here I will review the current state of the field, what we have learned from using C. elegans to study gut microbiome and host interactions, and the potential of using this model system in the future
Influence of modifying additives on formation of supported copper nanoparticles
The influence of modifying additives of Ce, Zr, La and Cs
oxides on changes of electronic state of supported copper during the
catalytic reaction of butane complete oxidation has been studied by the
methods of IR-spectroscopy of adsorbed CO, XPS, EXAFS and XRD. The modifying
additions of cerium and zirconium oxides stabilize the ionic state of
copper, while lanthanum and cesium oxides decrease the effective charge of
copper ions. The observed effects are caused by variation in metal
dispersivity in the modified samples and by electron donor-acceptor
interaction of the surface atoms and ions of copper with the modifier