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Boreal forest fires are currently recognized as a significant factor in climate change and air quality problems. Although emissions of biomass burning products are widely measured in many regions, there is still lack of information on the composition of wildfire emissions in Siberia, a region known for its severe wildfire activity. Emission ratios (ERs) are important characteristics of wildfire emissions as they may be used to calculate the mass of species emitted into the atmosphere due to combustion of a known mass of biomass fuel. We analyze observations of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), total nonmethane hydrocarbons (NMHCs), nitrogen oxides NOx ( = NO + NO2), particulate matter (PM3), and black carbon (BC) within two forest fire plume transects made by the moving railway observatory during TRanscontinental Observations Into the Chemistry of the Atmosphere (TROICA) expeditions. Slopes in linear regressions of excess levels of the pollutants are used to obtain ERCO ∕ CO2 = 10–15 %, ERCH4 ∕ CO = 8–10 %, ERNMHC ∕ CO = 0.11–0.21 % ppmC ppmC−1, ERNOx ∕ CO = 1.5–3.0 ppb ppm−1, ERPM3 ∕ CO = 320–385 ng m−3 (µg m−3)−1, and ERBC ∕ CO = 6.1–6.3 µg m−3 ppm−1, which fall within the range of uncertainty of the previous estimates, being at the higher edge for ERCH4 ∕ CO, ERNMHC ∕ CO, and ERPM3 ∕ CO and at the lower edge for ERNOx ∕ CO. The relative uncertainties comprise 5–15 % of the estimated ERCH4 ∕ CO, ERNMHC ∕ CO, and ERPM ∕ CO and 10–20 % of ERNOx ∕ CO, ERCO ∕ CO2, and ERBC ∕ CO. The uncertainties are lower than in many other similar studies and associated mainly with natural variability of wildfire emissions.

Abstract Background The complex relationship between oocyte morphology, specific follicular fluid metabolites, gene expression in cumulus granulosa cells, and oocyte competence toward fertilization and embryo development still needs further clarification. Methods Forty-six oocytes retrieved from the largest pre-ovulatory follicle of patients undergoing intra-cytoplasmic sperm injection (ICSI) were considered assessing: (a) oocyte morphological characteristics at polarized light microscopy (PLM), (b) specific follicular fluid (FF) metabolites previously suggested to influence oocyte competence (AMH, markers of redox status and of cytotoxicity), (c) transcription of AMH and AMH type II receptor genes in cumulus cells. Data were analyzed using mono-parametric tests and multivariable logistic analysis in order to correlate morphological and biochemical data with fertilization. Results Comparing normally fertilized oocytes (n = 29, F group) with unfertilized (n = 17, nF group) we observed that: (a) the meiotic spindle area and major axis were significantly higher in nF group and in fertilized oocytes undergoing an early embryo development arrest; (b) AMH level in FF was comparable in F and nF groups; (c) the FF of nF group contained significantly higher levels of cytotoxicity (lactate dehydrogenase) and oxidative stress (Cu,Zn-superoxide dismutase, catalase, 4-hydroxynonenal-protein conjugates) markers; (d) cumulus cells of nF group showed significantly higher AMH receptor type II gene expression. Conclusions Taken together, these observations suggest that an excessive cytotoxicity level can alter AMH signal transduction within cumulus cells, in turn leading to partial inhibition of aromatase activity, altered cytoplasmic maturation and increased oxidative stress, factors able to impair oocyte fertilization competence and embryo growth.

Volatile organic compounds (VOCs) were measured by proton transfer reaction mass spectrometry (PTR-MS) on a mobile laboratory in a transcontinental TROICA-12 (21 July–4 August 2008) campaign along the Trans-Siberian Railway from Moscow to Vladivostok. Surface concentrations of benzene (C6H6) and toluene (C7H8) along with non-methane hydrocarbons (NMHCs), CO, O3, SO2, NO, NO2 and meteorology are analyzed in this study to identify the main sources of benzene and toluene along the Trans-Siberian Railway. The most measurements in the TROICA-12 campaign were conducted under low-wind/stagnant conditions in moderately ( ∼ 78 % of measurements) to weakly polluted ( ∼ 20 % of measurements) air directly affected by regional anthropogenic sources adjacent to the railway. Only 2 % of measurements were identified as characteristic of highly polluted urban atmosphere. Maximum values of benzene and toluene during the campaign reached 36.5 and 45.6 ppb, respectively, which is significantly less than their short-term exposure limits (94 and 159 ppb for benzene and toluene, respectively). About 90 % of benzene and 65 % of toluene content is attributed to motor vehicle transport and 10 and 20 %, respectively, provided by the other local- and regional-scale sources. The highest average concentrations of benzene and toluene are measured in the industrial regions of the European Russia (up to 0.3 and 0.4 ppb for benzene and toluene, respectively) and south Siberia (up to 0.2 and 0.4 ppb for benzene and toluene, respectively). Total contribution of benzene and toluene to photochemical ozone production along the Trans-Siberian Railway is about 16 % compared to the most abundant organic VOC – isoprene. This contribution, however, is found to be substantially higher (up to 60–70 %) in urbanized areas along the railway, suggesting an important role of anthropogenic pollutant sources in regional ozone photochemistry and air quality.

The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic–boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land–atmosphere–aquatic–society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context.

Сonducted comparative analysis of the coordination compounds of Co2+, Ni2+, Cu2+ with condensation products of 2-(7-bromo-2-oxo-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepin-1-yl) acetohydrazide – Hydazepam (Hydr), nicotinoyl- and isonicotinoyl hydrazones (H2N, H2I) with pyruvic acid (HPv): [Co(HydrHPv)Cl2]·2H2O (I), [Ni(HydrPv)2] (II), [Cu(HydrHPv) (H2O)Cl2] (III), [CoCl(HNPv)(H2O)2] (IV), [CoCl(HIPv)(H2O)2] (V), [NiCl(HNPv)(H2O)2] (VI), [NiCl(HIPv)(H2O)2] (VII), [CuCl(HNPv)]·H2O (VIII), [CuCl(HIPv)]·H2O (IX). Complexes characterized by elemental analysis, IR spectroscopy, electrical conductivity, and magnetic susceptibility. Thermal stability of the complexes has been characterized. Structure of the coordination node of the complexes has been determined by EXAFS-spectroscopy. Regardless of composition, structure by heterocyclic nitrogen-containing moiety of the molecules HydrHPv, H2NРv, H2IРv formation of I-IX complexes is due to binding of complexing with a hydrazide functional group ketone form of the ligands. Ni2+ complexes II, VI, VII are different by composition (Ni2+:HydrHPv в II = 1:2, Ni2+:H2NРv(H2IРv) в VI, VII = 1:1). Co2+, Cu2+ complexes with the same composition (M2+:ligand = 1:1). H2NPv, H2IPv in all complexes IV-IX – tridentate, occurs deprotonation and bonding carboxylate group НPv. HydrHPv coordinated to the Co2+, Cu2+ bidentate (I, III), without participation of the carboxylic group, and to the Ni2+ – tridentate (II).

The aim of this study was to assess the oxidative stress status in eyes affected by synchysis scintillans and to compare it to vitreoretinal disorders without synchysis scintillans. Human aqueous and vitreous humors were obtained during vitrectomy from thirty-seven otherwise healthy patients that were randomly chosen among patients that had to undergo a 25-gauge pars plana vitrectomy from the central vitreous cavity, for either synchysis scintillans (n = 16) or vitreoretinal disorders without synchysis scintillans (n = 21), such as idiopathic epimacular membrane (n = 12), macular hole (n = 5), or rhegmatogenous retinal detachment (n = 4). The redox parameters thiobarbituric acid reactive substances (TBARS), a measurement of lipid peroxidation, nitrite concentration, an estimate of nitric oxide (NO) production, 4-hydroxynonenal (4-HNE)-protein conjugates, a structural protein modification by lipid peroxidation product 4-HNE, and the antioxidative activities of Cu,Zn-superoxide dismutase (SOD), and catalase were measured in aqueous and vitreous humors and compared between synchysis scintillans affected and not-affected patients. TBARS and nitrite levels of the vitreous humor were significantly higher in patients with synchysis scintillans as compared to patients affected by vitreoretinal disorders without synchysis scintillans. Synchysis scintillans patients had significantly lower activities of SOD and catalase both in aqueous and vitreous humors than patients with vitreoretinal disorders without synchysis. The consequently higher lipoperoxide-dependent 4-HNE production in synchysis scintillans was detectable in aqueous and vitreous humors as a significant increased accumulation of 4-HNE-protein conjugates vs nonsynchysis vitreoretinal disorders. Additionally, hyaluronic acid (HA) was significantly decreased in the vitreous body of synchysis scintillans patients. The data consistently show that synchisis scintillans is accompanied by a redox imbalance with increased oxidative modifications of 4-HNE proteins and loss of HA, both of likely importance for remote damages of the retina. It remains to be proven whether a therapeutic strategy which targets oxidative stress may be effective in the treatment of synchysis patients.

Volatile organic compounds (VOCs), ozone (O3), nitrogen oxides (NOx), carbon monoxide (CO), meteorological parameters, and total non-methane hydrocarbons (NMHC) were analyzed from simultaneous measurements at the MSU-IAP (Moscow State University—Institute of Atmospheric Physics) observational site in Moscow from 2011–2013. Seasonal and diurnal variability of the compounds was studied. The highest O3 concentration in Moscow was observed in the summer daytime periods in anticyclonic meteorological conditions under poor ventilation of the atmospheric boundary layer and high temperatures (up to 105 ppbv or 210 μg/m3). In contrast, NOx, CO, and benzene decreased from 8 a.m. to 5–6 p.m. local time (LT). The high positive correlation of daytime O3 with secondary VOCs affirmed an important role of photochemical O3 production in Moscow during the summers of 2011–2013. The summertime average concentrations of the biogenic VOCs isoprene and monoterpenes were observed to be 0.73 ppbv and 0.53 ppbv, respectively. The principal source of anthropogenic VOCs in Moscow was established to be local vehicle emissions. Yet, only about 5% of the observed isoprene was safely attributed to anthropogenic sources, suggesting significant contribution of biogenic sources into the total levels of ozone precursors. The non-linear O3–NOx dependence shows a decrease in ground-level O3 with an increase in NOx during the summers of 2011–2013, which is typical for the VOC-sensitive photochemical regime of O3 formation. Nevertheless, during the elevated ozone episodes in July 2011, the photochemical regime of ozone production was either transitional or NOx-sensitive. Contribution of various anthropogenic and biogenic VOCs into the measured ozone values was evaluated. The ozone-forming potential (OFP) of total VOCs was 31–67 μg/m3 on average and exceeded 100 μg/m3 in the top 10% of high ozone events, reaching 136 μg/m3. Acetaldehyde, 1.3-butadiene, and isoprene have the highest ozone production potential in Moscow compared to that of other measured VOCs.

Renewable energy production is gaining importance in the context of global climate changes. However, in some countries other aspects increasing the role of renewable energy production are also present. Such a country is Ukraine, which is not self-sufficient in energy supply and whose dependency on poorly diversified import of energy carriers regularly leads to political tensions and has socio-economic implications. Production of agricultural biogas seems to be a way to both slow down climatic changes and increase energy self-sufficiency by replacing or complementing conventional sources of energy. One of the most substantial barriers to agricultural biogas production is the low level of agricultural concentration and significant economies of scale in constructing biogas plants. The aim of the paper was thus to assess the potential of agricultural biogas production in Ukraine, including its impact on energy self-sufficiency, mitigation of greenhouse gas (GHG) emissions and the economic performance of biogas plants. The results show that due to the prevailing fragmentation of farms, most manure cannot be processed in an economically viable way. However, in some regions utilization of technically available manure for agricultural biogas production could cover up to 11% of natural gas or up to 19% of electricity demand. While the theoretical potential for reducing greenhouse gas emissions could reach 5% to 6.14%, the achievable technical potential varies between 2.3% and 2.8% of total emissions. The economic performance of agricultural biogas plants correlates closely with their size and bioenergy generation potential.

Results of the analysis of interannual, seasonal, and diurnal variations in the ratios of the mixture of CH4, CO2, CO, benzene, and δ13C–CH4 in the surface air of Moscow based on the measurements at the station of the Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS), in 2018–2020 are presented. The annual maximum concentration of CH4, CO2, and CO (>2.2, 430, and 0.20 ppm, respectively) occurs in the winter months due to the seasonal increase in the anthropogenic load from the main sources of urban pollution: motor transport and thermal power plants and a decrease in the role of vertical air mixing. The greatest contribution of local and remote microbial sources to the CH4 concentration is noted in the summer months against the background of low δ13C–CH4 values (–50 to –60‰). In all seasons, CH4, CO2, and CO ground level peaks lasting up to several hours are due to the transport from industrial sites in the E–SE sector. The calculated mean emission ratios in urban air were CH4/benzene = 0.52–0.54 ppm/ppb, CH4/СО = 0.56–0.75 ppm/ppm, CO2/benzene = 77–93 ppm/ppb, CO2/СО = 81–131 ppm/ppm, and CO/benzene = 0.65–1.11 ppm/ppb. These ratios characterize the predominant contribution of emissions from motor transport and the heat and power equipment and can be used to refine the absolute values of emissions, including those on the basis of existing inventories of sources of anthropogenic air pollution. [ABSTRACT FROM AUTHOR]