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In our large-scale search for antimicrobial-producing bacteria, we isolated an actinomycete strain from rhizospheric soil of Bambusa vulgaris. The strain designated BP-8 showed noticeable antibacterial activity. BP-8 was subjected to a whole-genome analysis via a polyphasic taxonomy approach, and its antibacterial metabolite was identified by HRLS-MS. The results of the physiological and morphological analyses indicated that BP-8 is an aerobic, neutrophilic, mesophilic organism that is tolerant to 8% NaCl and can use a wide range of carbohydrates. It forms curly sporophores with a warty surface. The results of the phylogenetic and average nucleotide identity analyses and in silico DNA–DNA hybridization calculation indicated that BP-8 represents the type strain of a novel Streptomyces species. A comparative in silico analysis of the genome sequences of BP-8 and its closest related strains revealed the presence of genes encoding chemotaxonomic markers characteristic of Streptomyces. The antibacterial compound was identified as amicetin. Genomic mining also revealed more than 10 biosynthetic gene clusters that have not been described previously and may lead to the discovery of new valuable compounds. On the basis of these results, strain BP-8T (=VKM Ac-3066T = CCTCC AA 2024094T) is proposed as the type strain of the novel species Streptomyces sirii sp. nov.

IntroductionThe increase in incidence of multidrug-resistant bacteria and the inadequacy of new antimicrobial drugs have led to a widespread outbreak of bacterial antimicrobial resistance. To discover new antibiotics, biodiversity, and novelty of culturable actinobacteria dwelled in soil of the Western Qinghai-Tibet Plateau were investigated. By integrating antibacterial assay with omics tools, Amycolatopsis sp. A133, a rare actinobacterial strain and its secondary metabolites were further studied.MethodCulture-dependent method was used to obtain actinobacterial strains from two soil samples collected from Ali region in Qinghai-Tibet Plateau. The cultural extractions of representative strains were assayed against “ESKAPE” pathogens by paper-disk diffusion method and the double fluorescent protein reporter “pDualrep2” system. An Amycolatopsis strain coded as A133 was prioritized and its secondary metabolites were further analyzed and annotated by omics tools including antiSMASH and GNPS (Global Natural Social Molecular Networking). The predicted rifamycin analogs produced by Amycolatopsis sp. A133 were isolated and identified by chromatographic separation, such as Sephadex LH-20 and HPLC, and spectral analysis, such as NMR and UPLC-HRESI-MS/MS, respectively.ResultsA total of 406 actinobacteria strains affiliated to 36 genera in 17 families of 9 orders were isolated. Out of 152 representative strains, 63 isolates exhibited antagonistic activity against at least one of the tested pathogens. Among them, 7 positive strains were identified by the “pDualrep2” system as either an inhibitor of protein translation or DNA biosynthesis. The cultural broth of Amycolatopsis sp. A133 exhibited a broader antimicrobial activity and can induce expression of TurboRFP. The secondary metabolites produced by strain A133 was annotated as rifamycins and zampanolides by antiSMASH and GNPS analysis. Five members of rifamycins, including rifamycin W, protorifamycin I, rifamycin W-M1, proansamycin B, and rifamycin S, were purified and identified. Rifamycin W-M1, was found as a new member of the naturally occurring rifamycin group of antibiotics.DiscussionAssisted by omics tools, the successful and highly efficient discovery of rifamycins, a group of clinically used antibiotics from actinobacteria in Ali area encouraged us to devote more energy to explore new antibiotics from the soils on the Western Tibetan Plateau.

To assess the state of the Panthera tigris altaica (hereinafter – tiger) population, its annual monitoring is being carried out on 16 sites within its range, as this subspecies is still considered threatened. These sites include state nature reserves and adjacent territories, which differ in their protection status. In this paper, a number of tiger individuals in groups and reproduction have been compared on these sites to identify factors that determine these parameters. The tiger population in the Lazovsky State Nature Reserve (area of 1210 km2) was compared with the tiger population in an unprotected area (area of 988 km2), which, similarly to the Protected Area, is located on the coast of the Sea of Japan. A description and comparison of these two sites is given. The study has been carried out in 1997–2021 in the Lazovsky State Nature Reserve, and in 1997–2012 in the unprotected site «Lazovsky District». During the winter, information was collected about tiger tracks in the study area, and data on predator tracks were collected out on stationary routes during two field counts. In the Lazovsky State Nature Reserve, the density of routes in various years was 1.0–1.5 km per 10 km2, 1.2 km per 10 km2 in the site «Lazovsky District». Tiger individuals were identified by the width of paw prints. Tracks differed by more than 2 cm were considered belonging to different individuals. Indicators of the tiger population was about twice higher in the Lazovsky State Nature Reserve than in the unprotected site «Lazovsky District». In 1997–2012, in both Lazovsky State Nature Reserve and unprotected site «Lazovsky District», the population density of both adult and subadult tigers was respectively 8.6 ± 0.7 individuals per 1000 km2 and 5.3 ± 0.5 individuals per 1000 km2, while this parameter was respectively 3.1 ± 1.0 individuals per 1000 km2 and 1.7 ± 0.04 individuals per 1000 km2 for tiger cubs younger than a year. The tiger track density in the Lazovsky State Nature Reserve was 3.03 ± 0.51 tracks per 100 km, taking into account the time passed after the snowfalls covering all tracks; on the site «Lazovsky District», this indicator was 1.33 ± 0.27 tracks per 100 km. In 1997–2012, the population density of adults and subadults was significantly (F = 59.40, p < 0.001) higher in the Lazovsky State Nature Reserve than on the site «Lazovsky District». The population density of tiger cubs (F = 6.30, p < 0.018) and the track density (F = 4.86, p < 0.036) were also significantly higher in the Protected Area than in the unprotected one. The survival rate of tiger cubs was also higher in the Lazovsky State Nature Reserve. Here, the proportion of tiger litters with one cub was 16% (n = 4), with two cubs 48% (n = 12), with three 32% (n = 8), and with four 4% (n = 1) of the total number. On the unprotected site «Lazovsky District», the proportion of litters with one cub was 53% (n = 8), with two 27% (n = 4), and with three 20% (n = 3) of the total number. A downward trend in the population density of tiger cubs was found on the site «Lazovsky District». In 2012–2021 in the Lazovsky State Nature Reserve, the average population density was 8.9 ± 1.8 individuals per 1000 km2 for adult and subadult tigers, and 4.3 ± 1.1 individuals per 1000 km2 for tiger cubs, while the average tiger track density was 2.39 ± 0.68 tracks per 100 km. During this period, the population density of tiger cubs decreased in the Protected Area, and there was also a tendency towards a decrease in the relative number of adults and subadults. The regular three-year cycle in the dynamics of the tiger track density in the Lazovsky State Nature Reserve indicates that environmental factors predominantly influence tiger groups here. No regular cycle was observed on the unprotected site «Lazovsky District». This finding and the lower number of tiger individuals in this area are associated with the negative impact of related anthropogenic factors, namely poaching, hunting, and logging. Recreational pressure also affects the tiger groups. In the last decade, the tiger group in the Lazovsky State Nature Reserve has been exposed to anthropogenic factors from the adjacent area. It is concluded that the further protection of the tiger and the increase in its number is possible if Protected Areas of various statuses are established, if extensive buffer zones are created around new and existing Protected Areas, if hunting is prohibited and logging is limited. The use of agricultural lands for other purposes around Protected Areas should be forbidden.

The Tibetan Plateau, known as the “Roof of the World” and “The Third Pole”, harbors numerous saline lakes primarily distributed in the Northern Tibetan Plateau. However, the challenging conditions of high altitude, low oxygen level, and harsh climate have limited investigations into the actinobacteria from these saline lakes. This study focuses on investigating the biodiversity and bioactive secondary metabolites of cultivable actinobacteria isolated from the sediments of four saline lakes on the Northern Tibetan Plateau. A total of 255 actinobacterial strains affiliated with 21 genera in 12 families of 7 orders were recovered by using the pure culture technique and 16S rRNA gene phylogenetic analysis. To facilitate a high-throughput bioactivity evaluation, 192 isolates underwent OSMAC cultivation in a miniaturized 24-well microbioreactor system (MATRIX cultivation). The antibacterial activity of crude extracts was then evaluated in a 96-well plate antibacterial assay. Forty-six strains demonstrated antagonistic effects against at least one tested pathogen, and their underlying antibacterial mechanisms were further investigated through a dual-fluorescent reporter assay (pDualrep2). Two Streptomyces strains (378 and 549) that produce compounds triggering DNA damage were prioritized for subsequent chemical investigations. Metabolomics profiling involving HPLC-UV/vis, UPLC-QTOF-MS/MS, and molecular networking identified three types of bioactive metabolites belonging to the aromatic polyketide family, i.e., cosmomycin, kidamycin, and hedamycin. In-depth analysis of the metabolomic data unveiled some potentially novel anthracycline compounds. A genome mining study based on the whole-genome sequences of strains 378 and 549 identified gene clusters potentially responsible for cosmomycin and kidamycin biosynthesis. This work highlights the effectiveness of combining metabolomic and genomic approaches to rapidly identify bioactive chemicals within microbial extracts. The saline lakes on the Northern Tibetan Plateau present prospective sources for discovering novel actinobacteria and biologically active compounds.

The article considers conceptual approaches to the development of the main educational program project for personnel training in the field of education, upbringing and support of students with autism spectrum disorders. It is indicated that the relevance of development of such program is determined by the existing imbalance between the request of parents, who are raising children with autism spectrum disorders, the requirements of the modern system of organized psychological and educational support of students of this category and the current situation of deficiency in providing this system with qualified, purposefully trained professionals. It is shown that the solution of the personnel issue is the key in setting priorities regulating public relations and state policy in the field of education. The discussion object and subject are actualized - conceptual approaches to the development and technology of the development of the main educational program for personnel training in the field of psychological and educational support of students with autism spectrum disorders. Basic conceptual settings of the project of the model main educational program aimed at bachelors training in the field of education and support of students with autism spectrum disorders described. Drafts of the professional competencies and the achievement indicators are designed. The program content is presented by possible disciplines modules.

Antibiotic resistance has been and remains a major problem in our society. The main solution to this problem is to search and study the mechanisms of antibiotic action. Many groups of secondary metabolites, including antimicrobial ones, are produced by the Actinomycetota phylum. The actinobacterial strains isolated from habitats that have not been well studied are of great interest. Due to high resource competition, antibiotics are now considered a 'trump card in the game of life' due to their presence in natural substrates with limited nutrients. Potentially, strains isolated from such habitats can be producers of novel or poorly studied antibiotics. In the current research, we identified the strain Streptomyces sp. AP22 from the soils of the Akhshatyrsky Gorge, which is capable of producing pentalenolactone. This study describes the phenotypic and morphological characteristics of Streptomyces sp. AP22 and its biological activity. Pentalenolactone is a known inhibitor of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), an important enzyme involved in glycolysis. We identified a previously unknown mutation in the gapA gene encoding glyceraldehyde-3-phosphate dehydrogenase that confers resistance to this antibiotic compound. This antibiotic is not used in clinical practice, so its application as a selectable marker will not lead to the creation of pathogens resistant to clinically relevant antibiotics. In this case, the selectable marker is based on a genetic construct containing the glyceraldehyde-3-phosphate dehydrogenase gene with a resistance mutation. The use of this selectable marker can be applied to various genetic and molecular techniques, such as cloning and transformation. This can help to facilitate genetic and molecular biology studies of strains resistant to standard selectable markers such as kanamycin or ampicillin. [ABSTRACT FROM AUTHOR]

In our large-scale search for antimicrobial-producing bacteria, we isolated an actinomycete strain from rhizospheric soil of Bambusa vulgaris. The strain designated BP-8 showed noticeable antibacterial activity. BP-8 was subjected to a whole-genome analysis via a polyphasic taxonomy approach, and its antibacterial metabolite was identified by HRLS-MS. The results of the physiological and morphological analyses indicated that BP-8 is an aerobic, neutrophilic, mesophilic organism that is tolerant to 8% NaCl and can use a wide range of carbohydrates. It forms curly sporophores with a warty surface. The results of the phylogenetic and average nucleotide identity analyses and in silico DNA–DNA hybridization calculation indicated that BP-8 represents the type strain of a novel Streptomyces species. A comparative in silico analysis of the genome sequences of BP-8 and its closest related strains revealed the presence of genes encoding chemotaxonomic markers characteristic of Streptomyces. The antibacterial compound was identified as amicetin. Genomic mining also revealed more than 10 biosynthetic gene clusters that have not been described previously and may lead to the discovery of new valuable compounds. On the basis of these results, strain BP-8T (=VKM Ac-3066T = CCTCC AA 2024094T) is proposed as the type strain of the novel species Streptomyces sirii sp. nov. [ABSTRACT FROM AUTHOR]

Since the discovery of streptomycin, actinomycetes have been a useful source for new antibiotics, but there have been diminishing rates of new finds since the 1960s. The decreasing probability of identifying new active agents led to reduced interest in soil bacteria as a source for new antibiotics. At the same time, actinomycetes remain a promising reservoir for new active molecules. In this work, we present several reporter plasmids encoding visible fluorescent protein genes. These plasmids provide primary information about the action mechanism of antimicrobial agents at an early stage of screening. The reporters and the pipeline described have been optimized and designed to employ citizen scientists without specialized skills or equipment with the aim of essentially crowdsourcing the search for new antibiotic producers in the vast natural reservoir of soil bacteria. The combination of mechanism-based approaches and citizen science has proved its effectiveness in practice, revealing a significant increase in the screening rate. As a proof of concept, two new strains, Streptomyces sp. KB-1 and BV113, were found to produce the antibiotics pikromycin and chartreusin, respectively, demonstrating the efficiency of the pipeline.

The specifics of the market relations cause the emergence of enterprise risks which, this way or the other, influence the economic security of economic entities. The economic nature of the category “economic security of an economic entity” represents a combination of the economic and legal conditions which provide steady functioning of enterprise structures in the long run. The essence of economic security comprises the elimination of risks such as the threat of decrease in business efficiency, legal matters, and the expediency of use of labor, financial, production and land resources with the help of lawful and effective methods. Analysis and diagnostics of financial and economic activity of economic entities are one of the main conditions that ensure economic security. The reliability of the results of the analysis and diagnostics of the condition of an enterprise depends generally on the reliability of the information used as the analytical base. It, in turn, is defined by the reliability of accounting system of the organization.

The fixed assets are among the most frequent types of assets of any enterprise, regardless of its industry sector, form of ownership, management and organizational-legal forms. The emergence of Provisions in the accounting of some objects raises a number of questions regarding their application, since regarding accounting as such, is not mentioned there at all, so this is becoming the reason of misunderstanding of their implementation in the domestic practice. Similar problems the accountants faced after the introduction of Chapter 25 of the Tax code of the Russian Federation, “Tax on profit of the organizations”. The Chapter established the rules of accounting for the purposes of calculating the tax base for tax on profit (tax accounting). The discrepancies which occurred as a result, as shown in the article, have no economic justification. Starting from 2011, many businesses ceased to create reserves for capital repair of their fixed assets, due to the fact that this year their establishment was abolished for accounting purposes, in accordance with the rules adopted by the PBU8/2010 “Estimated liabilities, contingent liabilities and contingent assets”, but for tax accounting purposes the formation of such reserves is still maintained. The situation was explained neither by accounting experts nor by tax experts.

Saxaul (Haloxylon ammodendron) is the most widespread plant community in the Gobi Desert in Mongolia, which plays important roles in wind control, sand fixation and water conservation. Investigations of soil-derived actinobacteria inhabiting in the saxaul forest in Gobi Desert in Mongolia have been scarce. In this study, biodiversity of culturable actinobacteria isolated from soil of the saxaul forest in Southern Gobi Aimak (Southern Gobi Province) of Mongolia was characterized and their potential to produce compounds with antibacterial activities was assessed. A total of 172 actinobacterial strains were recovered by culture-based approaches and were phylogenetically affiliated into 22 genera in 13 families of seven orders. Forty-nine actinobacterial isolates were selected to evaluate the antibacterial activities and their underlying mechanism of action was screened by means of a dual-fluorescent reporter assay (pDualrep2). Twenty-three isolates exhibited antagonistic activity against at least one of the tested pathogens, of which two Streptomyces strains can attenuate protein translation by ribosome stalling. Combinational strategies based on modern metabolomics, including bioassay-guided thin-layer chromatography (TLC), UPLC-QTOF-MS/MS based structural annotation and enhanced molecular networking successfully annotated chloramphenicol, althiomycin and granaticin and their derivatives as the antibacterial compounds from extracts in three Streptomyces strains, respectively. This work demonstrates that UPLC-MS/MS-based structural identification and enhanced molecular networking are effective strategies to rapidly illuminate the bioactive chemicals in the microbial extracts. Meanwhile, our results show that the saxaul forest in Mongolia Gobi Desert is a prospective source for discovering novel actinobacteria and biologically active compounds.

Understanding the distribution of aerosol layers is important for determining long-range transport and aerosol radiative forcing. In this study we combine airborne in situ measurements of aerosol with data obtained by a ground-based high spectral resolution lidar (HSRL) and radiosonde profiles to investigate the temporal and vertical variability of aerosol properties in the lower troposphere. The HSRL was deployed in Hyytiälä, southern Finland, from January to September 2014 as a part of the U.S. DOE ARM (Atmospheric Radiation Measurement) mobile facility during the BAECC (Biogenic Aerosols – Effects on Cloud and Climate) Campaign. Two flight campaigns took place in April and August 2014 with instruments measuring the aerosol size distribution from 10 nm to 5 µm at altitudes up to 3800 m. Two case studies with several aerosol layers present were selected from the flight campaigns for further investigation: one clear-sky and one partly cloudy case. During the clear-sky case, turbulent mixing ensured small temporal and spatial variability in the measured aerosol size distribution in the boundary layer, whereas mixing was not as homogeneous in the boundary layer during the partly cloudy case. The elevated layers exhibited larger temporal and spatial variability in aerosol size distribution, indicating a lack of mixing. New particle formation was observed in the boundary layer during the clear-sky case, and nucleation mode particles were also seen in the elevated layers that were not mixing with the boundary layer. Interpreting local measurements of elevated layers in terms of long-range transport can be achieved using back trajectories from Lagrangian models, but care should be taken in selecting appropriate arrival heights, since the modelled and observed layer heights did not always coincide. We conclude that higher confidence in attributing elevated aerosol layers to their air mass origin is attained when back trajectories are combined with lidar and radiosonde profiles.

The purpose of the article is to develop proposals for improving the efficiency of the forward-looking training system for the Russian Aviation Industry, located in the Volga Federal District. This territory is a concentration of enterprises of the machine-building complex, a significant part of which is represented by enterprises of the aviation industry. It is proposed to consider the aviation industry of the Volga Federal District as an interregional research and manufacturing cluster. The author presentation of the element composition of this cluster includes a production base, infrastructure, a system of state control, as well as consumers. As the core of this cluster, it is proposed to consider research and academic organizations, and industrial enterprises of the participant regions. Tatarstan is central to the Volga Federal District. This makes it a fairly convenient region in terms of logistics and interregional management of aviation industry enterprises. As the central headquarters of the interregional research and manufacturing cluster of the aviation industry, there is a scientific and educational institution in which scientific activity in the field of design and production of aviation equipment is set at a high level, as well as an extremely important function is implemented, namely the training of highly qualified personnel for the industry. The cases of KNRTU–KAI in the field of career guidance, teaching talented students, as well as the implementation of master’s degree programs are considered. Many universities have got number of other similar unique practices for organizing staffing for the future development of enterprises in the aviation industry. In the authors’ view, the significant potential for the development of the training system for the aviation industry lies in the efficient interaction between university communities within the Volga Federal District, as well as universities and employers. This will ensure consistency and continuity in training.

An original plasma chemical process initiated by microwave discharge in a mixture of metal and dielectric powders was applied to prepare specific materials, which consisted of microsized spherical particles of aluminum oxide covered with silver nanoparticles. The prepared materials are highly uniform in shape, size distribution, and composition. Their cytotoxicity was investigated using the human cell lines MCF7, HEK293T, A549, and VA-13 and the bacterial strains E. coli JW5503 (ΔtolC) and E. coli K12. Their cytotoxicity was found not to exceed the cytotoxicity of the starting materials. Thus, the prepared materials can be considered highly promising for catalysis and biotechnology applications. [ABSTRACT FROM AUTHOR]

We present tropospheric water vapor profiles measured with a Raman lidar during three field campaigns held in Finland. Co-located radio soundings are available throughout the period for the calibration of the lidar signals. We investigate the possibility of calibrating the lidar water vapor profiles in the absence of co-existing on-site soundings using water vapor profiles from the combined Advanced InfraRed Sounder (AIRS) and the Advanced Microwave Sounding Unit (AMSU) satellite product; the Aire Limitée Adaptation dynamique Développement INternational and High Resolution Limited Area Model (ALADIN/HIRLAM) numerical weather prediction (NWP) system, and the nearest radio sounding station located 100 km away from the lidar site (only for the permanent location of the lidar). The uncertainties of the calibration factor derived from the soundings, the satellite and the model data are −1); during summer it is wet (5.54±1.02 g kg−1); and at other times, the air is in an intermediate state. These are averaged values over the lowest 2 km in the atmosphere. Above that height a quick decrease in water vapor mixing ratios is observed, except during summer months where favorable atmospheric conditions enable higher mixing ratio values at higher altitudes. Lastly, the seasonal change in disagreement between the lidar and the model has been studied. The analysis showed that, on average, the model underestimates water vapor mixing ratios at high altitudes during spring and summer.

The subject of the study are manifestations of carbonatites in the quartz deposit “Vein № 175” - the largest deposit of granular quartz of Ufalei block in the Southern Urals. In the vein № 175 new outcrops of carbonatites are described; thin sections, plates and polished sections from 58 selected samples are made. Mineralogical and petrographic analysis of carbonatites and host rocks was carried out using Axiolab ZS and Olimpus BX 51 polarization microscopes with digital prefixes. The total mineral composition was determined by X-ray diffraction analysis. Fluid inclusions were studied in a Linkam THMSG-600 microcooler using the Olimpus BX 51-52 microscope and the LinkSistem 32 DVNS software. It was established that the deposition of vein quartz preceded to the formation of carbonatites. The quartz vein inherited a tectonic structure which controlled the deposition of carbonate material. The fragments of carbonatite bodies are observed throughout the quartz veins, where they have been preserved. It is established that the carbonatites of the “Vein 175” differ from the carbonatites of the Vishnevogorsk alkaline complex by a low content of rare metal minerals characteristic of carbonatites: pyrochlore, zircon, columbite, eshenite and monazite. It is obvious that the source of rare-metal minerals in the carbonatites of the Vishnevye Mountains, as well as in the magmatic carbonatites of zonal massifs with ultrabasic alkaline complexes, is the substance from which the alkaline rocks were formed. Carbonate rocks of these complexes concentrate rare-metal minerals and have the mantle spectrum of rare and rare-earth elements in their composition. The source of the carbonate material of “Veins № 175” can be sedimentary carbonates lying at the base of the crystalline basement. The absence of rare-metal minerals in the carbonatites confirm this thesis.

The relevance of this work lies in the fact that it attempts to disclose the key theoretical and practical issues of economic security solutions, taking into account the problems of global transformations taking place in the global economy. As part of the article we have been studied various aspects that characterize global economic, environmental trends that will shape the future of modern civilization. The article also addresses the problem of exit from the raw model of the economy, the formation of economic mechanisms that take into account environmental costs, proposed internalization of environmental externalities.The purpose/goal. The purpose of this article and its main task is to systematize the areas of environmentally oriented development of economic entities, as well as the determination of the list of key provisions of environmental policies, which will ensure the further socio-economic development of Russia in line with the green economy.Methods. In this article, based on content analysis of theoretical and empirical basic conceptual provisions of economic security were formulated in the context of eco-oriented production, the transition to which world civilization is currently implementing. It was concluded that the economic, energy, environmental and social issues of sustainable development of modern civilization is directly linked, so the transition to ecooriented production is possible, firstly, it provided aggressive reduction of production and wasteful use of traditional hydrocarbon resources, and, secondly, on the condition of rational replacement of traditional energy sources with renewable energy.Results. This article outlines the basic solutions that can be used to provide environmentally responsible operation and development of Russian business and corporate structures. Also offered in the basic decisions that are to be included in the national environmental policy as a major incentive for the further transition to a sustainable and green economy.Conclusions / relevance. The above article further aspects of environmentally responsible operation and development of Russian business and corporate structures can complement scientific and practical base solutions that provide active creation, implementation and use of green technologies to provide environmentally responsible sustainable socio-economic development.

Proxies for estimating nucleation mode number concentrations and further simplification for their use with satellite data have been presented in Kulmala et al. (2011). In this paper we discuss the underlying assumptions for these simplifications and evaluate the resulting proxies over an area in South Africa based on a comparison with a suite of ground-based measurements available from four different stations. The proxies are formulated in terms of sources (concentrations of precursor gases (NO2 and SO2) and UVB radiation intensity near the surface) and a sink term related to removal of the precursor gases due to condensation on pre-existing aerosols. A-Train satellite data are used as input to compute proxies. Both the input data and the resulting proxies are compared with those obtained from ground-based measurements. In particular, a detailed study is presented on the substitution of the local condensation sink (CS) with satellite aerosol optical depth (AOD), which is a column-integrated parameter. One of the main factors affecting the disagreement between CS and AOD is the presence of elevated aerosol layers. Overall, the correlation between proxies calculated from the in situ data and observed nucleation mode particle number concentrations (Nnuc) remained low. At the time of the satellite overpass (13:00–14:00 LT) the highest correlation is observed for SO2/CS (R2 = 0.2). However, when the proxies are calculated using satellite data, only NO2/AOD showed some correlation with Nnuc (R2 = 0.2). This can be explained by the relatively high uncertainties related especially to the satellite SO2 columns and by the positive correlation that is observed between the ground-based SO2 and NO2 concentrations. In fact, results show that the satellite NO2 columns compare better with in situ SO2 concentration than the satellite SO2 column. Despite the high uncertainties related to the proxies calculated using satellite data, the proxies calculated from the in situ data did not better predict Nnuc. Hence, overall improvements in the formulation of the proxies are needed.