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Voronin L.V.,Yaroslavl State Pedagogical University
Inland Water Biology | Year: 2010

Data on the occurrence, abundance, and species composition of fungi in the ecotopes of small acid lakes are presented. The role of fungi in acid-lake ecosystems is discussed. © 2010 Pleiades Publishing, Ltd. Source

Sarnpitak P.,Griffith University | Tsirulnikov S.,Yaroslavl State Pedagogical University | Krasavin M.,Griffith University
Tetrahedron Letters | Year: 2012

A hitherto undescribed TMSCl-promoted reaction of thiosemicarbazones was found to give rare N 1,N 3-disubstituted formamidrazones in fair to excellent yields. The scope of this new reaction was investigated and a plausible mechanism proposed. © 2012 Elsevier Ltd. All rights reserved. Source

Voronin L.V.,Yaroslavl State Pedagogical University
Inland Water Biology | Year: 2014

The occurrence, abundance, and taxonomical composition of fungi have been analyzed for different compounds of the freshwater ecosystems of various natural zones (from tundra to desert), particularly, for plankton, benthos, on living and dead plant substrates, and on some fish species. The role of terrigenous fungi in the freshwater ecosystems is discussed. © 2014, Pleiades Publishing, Ltd. Source

Krasavin M.,Yaroslavl State Pedagogical University | Parchinsky V.,Chemical Diversity Research Institute
Tetrahedron Letters | Year: 2010

A novel approach to skeletally diverse 3-oxoisoindolines has been developed which includes preparation of Ugi adducts containing thiophene and fumaric acid residues. When treated with excess m-CPBA at room temperature, these precursors undergo a simple oxidative cycloaddition/aromatization transformation and the corresponding 3-oxoisoindoline products are isolated in fair chemical yield over two steps. The second step is thought to include S-oxidation/IMDA/S-oxidation/ SO2 extrusion/aromatization events. © 2010 Elsevier Ltd. All rights reserved. Source

Wierzbowski H.,Polish Academy of Sciences | Rogov M.A.,Russian Academy of Sciences | Matyja B.A.,University of Warsaw | Kiselev D.,Yaroslavl State Pedagogical University | Ippolitov A.,Russian Academy of Sciences
Global and Planetary Change | Year: 2013

New isotope (δ18O, δ13C) and elemental (Mg/Ca, Sr/Ca) data of well-preserved belemnite rostra, ammonite and gastropod shells from the Middle Oxfordian-Lower Kimmerdgian (Densiplicatum-Kitchini zones) of the Russian Platform are presented. This record is supplemented with published data from the Upper Callovian-Lower Kimmeridgian interval (Athleta-Kitchini zones). Significant differences in average temperatures calculated from δ18O values of particular fossil groups (5-15°C) show the thermal gradient and the presence of cold bottom waters in the Middle Russian Sea during the Late Callovian-Middle Oxfordian. An Upper Oxfordian-lowermost Kimmeridgian decrease in δ18O values and an increase in Sr/Ca ratios of cylindroteuthid belemnite rostra likely reflect a warming of the bottom waters of ca. 3.5°C. The gradual Late Oxfordian-earliest Kimmeridgian warming is followed by an abrupt temperature rise of 3-6°C that occurred at the transition of the Early Kimmeridgian Bauhini and Kitchini chrons.The occurrences of cold bottom waters and of (Sub)Mediterranean ammonites and belemnites in the Middle Russian Sea at the Middle-Late Jurassic transition are regarded as a result of the opening of seaways during a sea level highstand. The bottom waters are considered to have been formed in the cool Boreal Sea. The subsequent retreats of the cold bottom waters and of the (Sub)Mediterranean cephalopods from the Middle Russian Sea in the Late Oxfordian are explained by the restriction of water circulation during a sea-level fall. The Early Kimmeridgian rise of bottom temperatures of the sea is linked to a global climate warming. The data presented do not support a major cooling of the Arctic and a consequent glaciation in this region at the Middle-Late Jurassic transition. Since occurrences of cold water masses are diachronous in different European basins, the observed variations in sea water temperatures are interpreted as a result of changes in marine currents and water circulation.δ13C values of belemnite rostra from the Russian Platform are scattered but show the long-term Upper Callovian-Middle Oxfordian positive excursion consistent with the previously published isotope records of the Boreal Realm and terrestrial organic matter. © 2013 Elsevier B.V. Source

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