Comparison of digital image analysis methods for morphometric characterization of soil aggregates in thin sections

The purpose of this study was to investigate the applicability of semiautomatic segmentation methods for obtaining and evaluating morphometric parameters of soil aggregates in artificially prepared loose samples in soil thin sections. The object of the research is typical arable Chernozem. The aggregates were separated by wet sieving method from loose sample of upper 10 cm of the plowing horizon after erosion by a model shallow water flow on a large erosion tray. The aggregates, loosely scattered on the glass and fixed with polyester resin, were used to produce the thin sections. Images of the thin sections were taken under a polarizing microscope and then were processed using two methods compared: Adobe Photoshop + CTan and Thixomet Pro. Data on morphometric parameters of aggregates were obtained: the shape factor, the degree of roundness and the coefficient of aggregate surface roughness. The convergence of the results obtained using Photoshop + CTan by three researchers was evaluated by comparing samples using the Student's test and the Mann-Whitney test. The convergence of the averaged results obtained using Photoshop + CTan and the results obtained using Thixomet Pro was evaluated using the Mann - Whitney test. No significant differences were found between the parameters of the same aggregates obtained using a combination of Adobe Photoshop and CTan programs by different researchers. No significant differences were found between the parameters of the same aggregates obtained by the compared methods. So, one can conclude that the reliability of determining the morphometric parameters of soil aggregates using Thixomet Pro is comparable to the reliability of results when working with images of sectionsin CTan after binarization in Adobe Photoshop. The method of obtaining data on morphometric parameters of soil aggregates using Thixomet Pro completely eliminates the possibility of subjective error, shows a high degree of automation, reproducibility and reliability of the results obtained, and is faster

Международный опыт восстановления объектов окружающей среды и его применение при производстве судебно-экологических экспертиз

The paper examines the issues of developing relevant and adequate methods to address the practical challenges of supporting the justice system with objective scientific evidence. Special emphasis is placed on the problem of ambiguity of the concept of «original» state of the environment prior to the investigated event and the choice of practical approaches to rehabilitation of damaged ecosystems.Рассмотрены вопросы разработки актуальных и адекватных методов, направленных на решение практических задач обеспечения судебной системы объективными результатами экспертных исследований. Особое внимание уделено проблеме неопределенности понятия «исходное» состояние объектов окружающей среды до расследуемого события и выбору путей восстановления объектов окружающей среды

Impact of Treadmill Running and Sex on Hippocampal Neurogenesis in the Mouse Model of Amyotrophic Lateral Sclerosis

Hippocampal neurogenesis in the subgranular zone (SGZ) of dentate gyrus (DG) occurs throughout life and is regulated by pathological and physiological processes. The role of oxidative stress in hippocampal neurogenesis and its response to exercise or neurodegenerative diseases remains controversial. The present study was designed to investigate the impact of oxidative stress, treadmill exercise and sex on hippocampal neurogenesis in a murine model of heightened oxidative stress (G93A mice). G93A and wild type (WT) mice were randomized to a treadmill running (EX) or a sedentary (SED) group for 1 or 4 wk. Immunohistochemistry was used to detect bromodeoxyuridine (BrdU) labeled proliferating cells, surviving cells, and their phenotype, as well as for determination of oxidative stress (3-NT; 8-OHdG). BDNF and IGF1 mRNA expression was assessed by in situ hybridization. Results showed that: (1) G93A-SED mice had greater hippocampal neurogenesis, BDNF mRNA, and 3-NT, as compared to WT-SED mice. (2) Treadmill running promoted hippocampal neurogenesis and BDNF mRNA content and lowered DNA oxidative damage (8-OHdG) in WT mice. (3) Male G93A mice showed significantly higher cell proliferation but a lower level of survival vs. female G93A mice. We conclude that G93A mice show higher hippocampal neurogenesis, in association with higher BDNF expression, yet running did not further enhance these phenomena in G93A mice, probably due to a ‘ceiling effect’ of an already heightened basal levels of hippocampal neurogenesis and BDNF expression

Purinergic modulation of microglial cell activation

Microglial cells are resident macrophages in the brain and their activation is an important part of the brain immune response and the pathology of the major CNS diseases. Microglial activation is triggered by pathological signals and is characterized by morphological changes, proliferation, phagocytosis and the secretion of various cytokines and inflammatory mediators, which could be both destructive and protective for the nervous tissue. Purines are one of the most important mediators which regulate different aspects of microglial function. They could be released to the extracellular space from neurons, astrocytes and from the microglia itself, upon physiological neuronal activity and in response to pathological stimuli and cellular damage. Microglial activation is regulated by various subtypes of nucleotide (P2X, P2Y) and adenosine (A1, A2A and A3) receptors, which control ionic conductances, membrane potential, gene transcription, the production of inflammatory mediators and cell survival. Among them, the role of P2X7 receptors is especially well delineated, but P2X4, various P2Y, A1, A2A and A3 receptors also powerfully participate in the microglial response. The pathological role of microglial purine receptors has also been demonstrated in disease models; e.g., in ischemia, sclerosis multiplex and neuropathic pain. Due to their upregulation and selective activation under pathological conditions, they provide new avenues in the treatment of neurodegenerative and neuroinflammatory illnesses

Micromorphological evaluation of features of dry-land farming soils whithin kastanozems (chestnut) - solonetz soil complex in the Stavropol region

The polygenetic nature and polymorphism of the soils of kastanozems-solonetz complexes determine the difficulty of their field diagnostics and further genetic interpretations. In the current study, micromorphological features are used as additional diagnostic characteristics, specifying genetic interpretations for the soils of the kastanozems (chesynut)-solonetz complex (chestnut solonetz, chestnut solonetzic soil, chestnut soil, chestnut-like meadow soil) used in agriculture (dryland farming) within the Apanasenkovsky District of Stavropol region. An attempt has been made to correlate the results of micromorphological research, which was performed to evaluate the role of micromorphologycal investigation in clarification of macromorphological description, with data obtained through physical and chemical analyses. First, this study reveals that the Kastanozem (Chestnut) soil have the best correlation between macromorphological description and data of micromorphological investigation. In meadow-chestnut, solonetzic-type and solonetz soils micromorphological investigation helps to realize a set of pedofeatures such as complex multilayered coatings with layers of different genesis, Red-Ox features, etc. Finally, micromorphological investigation allows better interpretation and understanding of physico-chemical data