Conformational Analysis of the Oligosaccharides Related to Side Chains of Holothurian Fucosylated Chondroitin Sulfates

Anionic polysaccharides fucosylated chondroitin sulfates (FCS) from holothurian species were shown to affect various biological processes, such as metastasis, angiogenesis, clot formation, thrombosis, inflammation, and some others. To understand the mechanism of FCSs action, knowledge about their spatial arrangement is required. We have started the systematic synthesis, conformational analysis, and study of biological activity of the oligosaccharides related to various fragments of these types of natural polysaccharides. In this communication, five molecules representing distinct structural fragments of chondroitin sulfate have been studied by means of molecular modeling and NMR. These are three disaccharides and two trisaccharides containing fucose and glucuronic acid residues with one sulfate group per each fucose residue or without it. Long-range C–H coupling constants were used for the verification of the theoretical models. The presence of two conformers for both linkage types was revealed. For the Fuc–GlA linkage, the dominant conformer was the same as described previously in a literature as the molecular dynamics (MD) average in a dodechasaccharide FCS fragment representing the backbone chain of the polysaccharide including GalNAc residues. This shows that the studied oligosaccharides, in addition to larger ones, may be considered as reliable models for Quantitative Structure-Activity Relationship (QSAR) studies to reveal pharmacophore fragments of FCS.     

RAPD marker evaluation of phylogenetic relationships in species of genus Beta L.

RAPD markers are used for establishing phylogenetic relationships between and within various beet species. On the basis of the electrophoretic profiles obtained, phylogenetic trees are constructed by the unweighted pair group with arithmetic mean (UPGMA) method and relationships between wild and cultivated beet accessions stored in the world collection at the Vavilov Plant Industry Research Institute (VIR)are determined.     

Natural or assisted succession as approach of forest recovery on abandoned lands with different land use history in the Andes of Southern Ecuador

Forest recovery on disturbed areas is of special significance in the Ecuadorian Andes, where deforestation is a serious problem. Natural diachronic succession was evaluated on three large plots or sites, differing in their land use and vegetation composition, one is dominated by grass species on an abandoned pasture (Pasture site), the other two are post-fire vegetation dominated by bracken (Bracken site) and various shrubs (Shrub site). Additionally, we assessed the effectiveness of manual removal of competitive herbaceous species to accelerate forest recovery. Monitoring was done in 2003, 2005 and 2007 on 48 subplots of 116 m² each recording species richness and woody-species density. Results showed that the Pasture site demonstrated a competitive effect of exotic grasses on woody species recruitment with much lower species recruitment and density, suggesting serious inhibition of natural forest regeneration and an unclear successional trajectory. The Bracken and Shrub sites became significantly similar floristically and there is evidence for a marked facilitation of woody plant recruitment correlated with light availability on the ground. Both sites showed characteristics of classic succession, with Shrub showing a higher species richness and density while late-successional species are poorly represented on the Bracken site. However, NMDS ordination using species density showed that the two trajectories may not be converging towards a common “final state”. Manual weeding was ineffective for accelerating forest recovery. These results suggest that the main limiting factor for the recruitment of woody species on the Pasture site is strong grass competition and must be addressed before seed availability, while seed availability seems to be the constraining factor for Bracken and Shrub site development, thus direct seeding or planting may be effective in accelerating forest recovery.     

The East-Mediterranean cereal leaf miner <Emphasis Type="Italic">Syringopais temperatella</Emphasis> Lederer and its larval parasitoids in Israel

Leaves of durum wheat infested with mines of the cereal leaf miner Syringopais temperatella Lederer (Lepidoptera: Scythridae) were collected from fields in Israel in spring 2016 and 2017. The parasitoids and moths reared from the leaf mines in the lab were identified and counted according to sex. The sex ratios of S. temperatella were 1:0.73 (♀ :♂) in 2016 and 1:0.41 in 2017. A cross-correlation analysis revealed that males appeared three days ahead of females (p<0.05). The following parasitoids were reared: Eulophidae (Cirrospilus vittatus Walker, Diglyphus chabrias (Walker), D. isaea (Walker), D. sensilis Yefremova, D. pusztensis (Erd?s & Novicky), Necremnus tidius (Walker), Neochrysocharis formosus (Westwood), Pnigalio gyamiensis Myartseva & Kurashev, P. pectinicornis Linnaeus), Pteromalidae (Norbanus sp.) and Braconidae (Habrobracon stabilis (Wesmail), Apanteles sp.); and Icheumonidae (Campoplex sp.). In all cases, the parasitoids emerged substantially prior to the mass appearance of the moths. The hatching dynamics of ecto- and endoparasitoids were also asynchronous. Most species of ectoparasitoids hatched three days ahead of the endoparasitoids (p<0.05). Syringopais temperatella recorded on clover revealed a similar dynamics of male appearance ahead of female, with a of female-to-male ratio of 1:0.25, and fewer parasitoid species.     

Fluctuating fine-scale spatial genetic structure in the common shrews (Eulipotyphla,Mammalia)

The spatial genetic structure is a topical issue in the studies of various aspects of ecology and evolution. Using the multilocus autocorrelation method with hypervariable microsatellite genetic markers, we investigated a fine-scale pattern of genetic structure in 5 local populations of the common shrew Sorex araneus separated by distances of 300–1000 m (the Moscow chromosomal race). Spatial genetic autocorrelation analysis based on 5 microsatellite loci (expected heterozygosity >0.79) with 90 alleles revealed a consistent pattern of significant positive genetic structure. By testing the autocorrelation at multiple scales from 25 to 500 m, we found that positive spatial genetic structure is detectable in distance classes of <500 m. The weaker spatial genetic structure positively correlated with a higher ratio of nonresident individuals to residents’ activity (number of captures). In contrast to nonresident animals, the residents demonstrated prominent genetic structure. Genetic difference (F_ST) between the populations was significant (0.016–0.051) and comparable with that between populations of different races analyzed previously (0.016–0.038). F_ST was not associated with geographic distance. These demographic patterns allowed us to propose a scheme of genetic-structure dynamics involving periodic appearance of more related local groups and renewal of allelic profiles from а common pool where the alleles are mixed. The scheme predicts fluctuating genetic structure and random similar differences among local populations.     

Serum markers of lipid peroxidation, antioxidant enzymatic defense, and collagen degradation in an experimental (Pond-Nuki) canine model of osteoarthritis

BACKGROUND:Chondrocyte lipid peroxidation is strongly suggested to mediate collagen degradation and thus, to be involved in the pathogenesis of cartilage degradation and osteoarthritis (OA). OBJECTIVES: The objective of this study was to evaluate early changes in serum biochemical indicators of oxidative stress during the development of OA in a canine model. METHODS: Experimental OA was induced in 7 dogs by transection of the anterior cruciate ligament (Pond-Nuki model). Venous blood samples were obtained prior to the operation and on postoperative days 30, 60, and 105. The activity of serum catalase (an antioxidant enzyme), malondialdehyde (MDA) concentration (a marker of lipid peroxidation), and serum C2C neoepitope concentration (a marker of collagen type II degradation) were measured. RESULTS: A statistically significant increase in all parameters as early as the 30th postoperative day was observed, compared with preoperative values. Serum catalase activity peaked on day 60, whereas MDA and C2C concentrations increased continuously until the end of the experimental period. A significant positive correlation was found between MDA and C2C concentrations, but not between catalase activity and MDA or C2C concentrations. CONCLUSIONS: The results support the hypothesis that oxidative stress is involved in the pathogenesis of OA in the dog based on the Pond-Nuki model. The correlation between MDA and C2C concentrations suggests a possible association between oxidative stress and cartilage degeneration.     

Integrated study of benthic foraging resources for Atlantic walrus (Odobenus rosmarus rosmarus) in the Pechora Sea,south-eastern Barents Sea

1. The Atlantic walrus, Odobenus rosmarus rosmarus, forms a herd of nearly 4,000 heads in the Pechora Sea (south-eastern Barents Sea). The Near Threatened status of O. rosmarus rosmarus and the relative isolation of the Pechora Sea population, as well as the potential impacts of human activities in the area, make it important to characterize key habitats, including feeding grounds, in order to protect the species.
2. The aim of the present study was to integrate multiple sources of environmental and biological data collected by satellite telemetry, remotely operated vehicle (ROV), and benthic grab sampling to examine the distribution and diversity of benthic foraging resources used by walrus in the Pechora Sea.
3. Analysis of satellite telemetry data from seven males tagged on Vaigach Island helped to identify areas of high use by walruses near haulout sites on Matveev and Vaigach islands, and in between. Field data were collected from those feeding grounds in July 2016 using ROV video recordings and bottom grab sampling. Analysis of 19 grab stations revealed a heterogeneous macrobenthic community of 133 taxa with a mean biomass of 147.11 ± 7.35 g/m². Bivalve molluscs, particularly Astarte borealis, Astarte montagui, and Ciliatocardium ciliatum, dominated the overall macrobenthic biomass, making up two-thirds of the total.
4. Analysis of 16 ROV video transects showed high occurrences of mobile benthic decapods (3.03 ± 2.74 ind./min) and provided the first direct evidence that areas actively used by walrus in the Pechora Sea overlap with the distribution of the non-native omnivorous snow crab, Chionoecetes opilio.
5. Integrating multiple data sources provides an early foundation for the kinds of ecosystem-based approaches needed to improve Pechora Sea resource management and to underpin Russia’s nascent marine spatial planning initiatives. Factors that need to be considered in marine spatial planning include impacts on benthic feeding grounds from offshore oil and gas development and the spread of the snow crab.

     

Raman-assisted crystallography reveals end-on peroxide intermediates in a nonheme iron enzyme

Iron-peroxide intermediates are central in the reaction cycle of many iron-containing biomolecules. We trapped iron(III)-(hydro)peroxo species in crystals of superoxide reductase (SOR), a nonheme mononuclear iron enzyme that scavenges superoxide radicals. X-ray diffraction data at 1.95 angstrom resolution and Raman spectra recorded in crystallo revealed iron-(hydro)peroxo intermediates with the (hydro)peroxo group bound end-on. The dynamic SOR active site promotes the formation of transient hydrogen bond networks, which presumably assist the cleavage of the iron-oxygen bond in order to release the reaction product, hydrogen peroxide.     

Weak northern and strong tropical land carbon uptake from vertical profiles of atmospheric CO2

Measurements of midday vertical atmospheric CO2 distributions reveal annual-mean vertical CO2 gradients that are inconsistent with atmospheric models that estimate a large transfer of terrestrial carbon from tropical to northern latitudes. The three models that most closely reproduce the observed annual-mean vertical CO2 gradients estimate weaker northern uptake of -1.5 petagrams of carbon per year (Pg C year(-1)) and weaker tropical emission of +0.1 Pg C year(-1) compared with previous consensus estimates of -2.4 and +1.8 Pg C year(-1), respectively. This suggests that northern terrestrial uptake of industrial CO2 emissions plays a smaller role than previously thought and that, after subtracting land-use emissions, tropical ecosystems may currently be strong sinks for CO2.     

New alternative method of benzo[a]pyrene extractionfrom soils and its approbation in soil under technogenic pressure

Purpose

The optimization of benzo[a]pyrene extraction conditions by subcritical water extraction method from soils is the purpose of the research. The optimal conditions for benzo[a]pyrene recovery are 30-min extraction by water in a special steel cartridge at 250 °C and 100 atm.

Materials and methods

Studies were conducted on the soils of monitoring plots subjected to Novocherkassk Power Station emissions. Monitoring plots were established at different distances from the Novocherkassk Power Station (NPS; 1.0–20.0 km).

Results and discussion

It was shown that the use of water in subcritical state as a solvent for benzo[a]pyrene extraction from soil allows to avoid large volumes of organic solvents and to decrease the time of sample preparation. It is shown that the maximum benzo[a]pyrene maintenance was observed in soils of the monitoring plots located most close (to 5 km) to a pollution source in the area of the prevailing direction of a wind rose. Dynamics of pollutant accumulation in soils depend on number of Novocherkassk state district power station emissions.

Conclusions

The method of benzo[a]pyrene subcritical water extraction from soil was developed and approbated during long-term monitoring researches of technogenic polluted territories. The optimum conditions for benzo[a]pyrene extraction from soil have been determined: the soil is treating by subcritical water at 250 °C and 100 atm of pressure for 30 min. Trends in the accumulation of benzo[a]pyrene in soil zones of the thermal power plant influence have been researched over a 5-year period of monitoring observations by subcritical water extraction method. Benzo[a]pyrene accumulation in soils depends on the technogenic emissions to the atmosphere from Novocherkassk power station and on the soil physical and chemical properties.