•Laser method for synthesis of bimetallic materials for enzyme-free microbiosensors.•Relationship between the structure of complexes and the properties of microbiosensors is shown.•The gap in ...knowledge about the structure of bimetal wine complexes has been filled.
The use of laser methods for synthesizing new materials for non-enzymatic electrochemical microsensors for express analysis of biological fluids is a promising scientific question.
Laser-induced chemical liquid phase deposition is the laser deposition of invisible miniature bimetallic deposits from aqueous solutions of salts and complexes of transition metals. Bimetallic complexes containing two transition metal cations in the shell of one ligand are of increased interest. There is an information gap in this area even for ligands such as tartrate. The studies carried out make it possible to obtain new information on the structure of bimetallic tartaric complexes in solutions containing simultaneously copper, nickel, silver, iron, and cobalt.
Space observations (1979–2020) have shown that, over the past 40 years, years with a decrease in the area of summer ice and their thickness prevailed. Over 10 years, negative trends of anomalies in ...the area and thickness of the ice are –13 and –15%, respectively. A rapid reduction in the area of old ice (>4-year-old) is also noted, because in 1985 it was estimated at 2.7 million km
2
, while in March 2010 it was 0.34 million km
2
. The paper analyses paleo sea ice extent during the Holocene (the last 12 000 years) based on empirical IP
25
biomarkers (a sea ice proxy with 25 carbon atoms synthesized by the specific Arctic sea ice diatoms
Haslea
spp, which have been proven to be a suitable proxy for paleo-sea ice reconstructions) obtained from deep-sea cores from the North Atlantic. The data showed that, during the warm periods of the Early and Middle Holocene, the area of summer sea ice was reduced to a minimum. This confirms the conclusion made earlier in (Kinnard et al., 2011) that the current trend of reducing the area and thickness of ice is unprecedented over the past 1500 years. There is no complete analogue of the climate in the past corresponding to the current level of the CO
2
concentration in the atmosphere. The period with CO
2
concentrations in the atmosphere similar to the current level was the warm part of the Middle Pliocene between 3 and 4 million years ago with level of the CO
2
concentration 450–500 ppm against approximately 420 ppm at present. Paleo-climate reconstructions for this period estimate the global temperature to be 3.0–3.5 ± 0.5°C higher than at the end of the 19th century. Summer air temperatures in the high latitudes of the Northern Hemisphere exceeded the current ones by 8–10°C, and the sea ice in the Arctic shelf seas was completely absent in the summer. Empirical data and model simulations have shown that presently the main driver of the reduction of the Arctic sea ice area is the increase in concentration of CO
2
in the atmosphere. At the present time, old sea ice tends to be replaced by seasonal ice, demonstrating a natural shift from the predominance of permanent ice to an ice-free Arctic. In the case of a continuous increase in CO
2
concentration in the atmosphere despite emission control measures, one of the scenarios that happened in the past may occur again.
Data on modern climate and environmental changes in Eastern Siberia are compared with the public perception of such changes through cognitive indicators. Observations reveal positive air temperature ...trends for all seasons, shortening of the cold period, decrease in wintertime daily temperature variations, deeper seasonal thawing of permafrost, and lengthening of the vegetation period. The public perception acknowledges these changes only partly, although they already affect many types of human’s activity. The gap between observational data and the cognitive indicators of climate change complicates the development and implementation of climate adaptation strategies.
Data on modern climate and environmental changes in the northwestern region of Russia are compared with the public perception of such changes. The analysis reveals that unusual weather patterns and ...single extreme events have a deeper impact on the public perception than long-term periods of climate change. The majority of population consider climate and environmental changes locally, do not associate them with global drivers, and are not prepared to adaptation. The numerical climate perception index is developed to characterize the awareness of population about the climate change and preparedness to adaptation. The index can be used for improving the awareness of policymakers for regional climate adaptation.
Rating is one of the methods of economic analysis used for comparative assessment of effectiveness of production and economic operation of the organizational structures in different branches of ...economy. Rating assessment of railways is used in JSC “RZD” since 2018 for objective assessment of economic and financial sustainability and effectiveness of management of structural divisions (branches). Methods of rating assessment adapted for structural divisions of JSC “RZD” with regard to the specificity of their operation are examined in the work.
Main objectives of establishing the rating assessment system of financial and economic operation of the JSC “RZD” branches are examined, detailed rating classification is presented.
Basic principles are developed for establishing the rating assessment system of operation effectiveness of the deputies of the JSC “RZD” branches heads in terms of financial and economic operation, as well as classification of indicators of financial and economic operation of the JSC “RZD” branches by types of operation with definition of their vector orientation.
The following conclusions are made:
1. Presented rating assessment is an indicator of the quality of financial and economic operation management of the JSC “RZD” branches.
2. Use of rating assessment for results analysis is relevant for motivation of the management in charge for economic operations.
3. Further development of the rating assessment system consists in establishing the events classifier and optimization of the current expenses.
Abstract
Although metabarcoding is a well-established tool for describing diversity of pelagic communities, its quantitative value is still controversial, with poor correlations previously reported ...between organism abundance/biomass and sequence reads. In this study, we explored an enhanced quantitative approach by metabarcoding whole zooplankton communities using a highly degenerate primer set for the mitochondrial marker cytochrome oxidase I and compared the results to biomass estimates obtained using the traditional morphological approach of processing zooplankton samples. As expected, detected species richness using the metabarcoding approach was 3–4 times higher compared to morphological processing, with the highest differences found in the meroplankton fraction. About 75% of the species identified using microscopy were also recovered in the metabarcoding run. Within the taxa detected using both approaches, the relative numbers of sequence counts showed a strong quantitative relationship to their relative biomass, estimated from length-weight regressions, for a wide range of metazoan taxa. The highest correlations were found for crustaceans and the lowest for meroplanktonic larvae. Our results show that the reported approach of using a metabarcoding marker with improved taxonomic resolution, universal coverage for metazoans, reduced primer bias, and availability of a comprehensive reference database, allow for rapid and relatively inexpensive processing of hundreds of samples at a higher taxonomic resolution than traditional zooplankton sorting. The described approach can therefore be widely applied for monitoring or ecological studies.
Glendonites and seep-related carbonate bodies from the Jurassic/Cretaceous boundary interval of West Spitsbergen were studied using mineralogical, isotopic, and geochemical methods. The stratigraphic ...distribution of seep-related carbonate bodies and glendonites (pseudomorphs after ikaite, Ca(CO
3
)·6H
2
O) reveals that although they can be occasionally found close to each other, their formation differs through time. Seep carbonates are found in the Oxfordian, Kimmeridgian, Volgian, and Ryazanian deposits, while glendonites appear in the Valanginian–Hauterivian and Middle Aptian–Lower Albian deposits of West Spitsbergen. Furthermore, numerous appearances of seep carbonates correlate with warming and shelf dysoxic–anoxic events in the Arctic, while glendonite occurrences correlate with cooling events. The δ
13
C values obtained for seep-related carbonates and glendonite samples reflect mixed sources including thermogenic and biogenic methane, oil fractions, decomposing organic matter, and dissolved inorganic carbon. We assume the precipitation of seep carbonates was caused by methanogenesis and anaerobic oxidation of organic matter promoting dense communities of benthic organisms and carbonate precipitation in warm climatic condition. At the end of the Ryazanian, shallowing of the basin coupled with climate cooling led to decrease in methanogenesis and anaerobic decomposition of methane and organic matter. Locally, in areas of anaerobic organic matter oxidation under low bottom temperatures, ikaite crystallized.
Graphical abstract
This database of Phanerozoic occurrences and isotopic
characteristics of metastable cold-water calcium carbonate hexahydrate
(ikaite; CaCO3⚫6H2O) and their associated carbonate
pseudomorphs ...(glendonites) has been compiled from academic publications,
explanatory notes, and reports. Our database including more than 700
occurrences reveals that glendonites characterize cold-water environments,
although their distribution is highly irregular in space and time. A
significant body of evidence suggests that glendonite occurrences are
restricted mainly to cold-water settings; however they do not occur during
every glaciation or cooling event of the Phanerozoic. While Quaternary
glendonites and ikaites have been described from all major ocean basins,
older occurrences have a patchy distribution, which may suggest poor
preservation potential of both carbonate concretions and older sediments. The data file described in this paper is available on Zenodo at
https://doi.org/10.5281/zenodo.4386335 (Rogov et al., 2020).
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