Areas Of Bulgaria Research Articles

Chemical Composition and Antioxidant Activities of Three Bulgarian Garden Thyme Essential Oils

Garden thyme (Thymus vulgaris L.) is an annual herbaceous plant of the family Lamiaceae. It can be found both in the wild and as a cultivated plant in Bulgaria. This study is aimed at assessing the garden thyme essential oil composition and antioxidant activities, which were collected from three different areas in Bulgaria. The essential oils were obtained by hydrodistillation and analyzed by gas chromatography–mass spectrometry (GC-MS). The main compounds in the garden thyme essential oils (over 2%) were as follows: thymol (42.88–53.55%), p-cymene (14.25–25.51%), γ-terpinene (6.58–15.51%), borneol (2.75–3.57%), carvacrol (2.00–3.02%), β-linalool (2.07–2.31%), cis-sabinene hydrate (4.05%), eucalyptol (1.08–3.65%), α-terpinene (1.01–3.24%), carvacrol methyl ether (1.18–3.02%), and thymol methyl ether (2.26–3.16%). The oils were mainly composed of oxygenated phenyl propanoids, and all the essential oils belonged to the chemotype thymol. Antioxidant activities were measured by DPPH (2,2-diphenyl-1-picrylhydrazyl radical) and ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] assays. All the samples exhibited antioxidant activity relative to the DPPH radical (from 143.20 mM TE/mL to 165.91 mM TE/mL) and by the ABTS method (from 121.67 mM TE/mL to 127.62 mM TE/mL). These garden thyme essential oils could be used as natural antioxidants for food and as nutraceuticals.

Clinical and Epidemiological Study of Multiple Sclerosis in Svoge and Troyan

Multiple sclerosis is a chronic inflammatory, autoimmune, demyelinating and neurodegenerative disease of the central nervous system. It is characterized by various symptoms depending on the area affected – brain, spinal cord or optic nerves. Multiple sclerosis typically presents at age 20–40 years and affects women more often than men. It is the most frequent nontraumatic disease causing neurologic deficit among young people. According to the 3rd edition of Atlas of MS, published by The Multiple Sclerosis International Federation in 2020, there are 2.8 million people living with the disease around the world. The last study on the epidemiology of multiple sclerosis in Bulgaria was published in 1999. It estimated prevalence of 44.5/100 000 and incidence 1.03/100 000. We present an epidemiological study conducted between January 2016 and December 2020 in two small areas in Bulgaria with homogenous and stable population – Svoge and Troyan. The estimated prevalence of multiple sclerosis in Troyan was 116.5/100 000 with incidence of 28.2/100 000. The prevalence and incidence of multiple sclerosis in Svoge were 117.7/100 000 and 24.5/100 000, respectively. The reason for the higher prevalence and incidence rates in our study may be explained by the better diagnosis of the disease according to well defined diagnostic criteria, the longer survival of the affected individuals and the availability of various disease modifying therapies.

A Methodological Framework for High-Resolution Surface Urban Heat Island Mapping: Integration of UAS Remote Sensing, GIS, and the Local Climate Zoning Concept

The urban heat island effect (UHI) is among the major challenges of urban climate, which is continuously intensifying its impact on urban life and functioning. Against the backdrop of increasingly prolonged heatwaves observed in recent years, practical questions about adaptation measures in cities are growing—questions that traditional meteorological monitoring can hardly answer adequately. On the other hand, UHI has long been the focus of research interest, but due to the technological complexity of providing accurate spatially referenced data at high spatial resolution and the requirement to survey at strictly defined parts of the day, information provision is becoming a major challenge. This is one of the main reasons why UHI research results are less often used directly in urban spatial planning. However, advances in geospatial technologies, including unmanned aerial systems (UASs), are providing more and more reliable tools that can be applied to achieve better and higher-quality information resources that adequately characterize the UHI phenomenon. This paper presents a developed and tested methodology for the rapid and efficient assessment and mapping of the effects of surface urban heat island (SUHI). It is entirely based on the integrated use of data from unmanned aerial systems (UAS)-based remote sensing methods, including thermal photogrammetry and GIS-based analysis methods. The study follows the understanding that correct SUHI research depends on a proper understanding of the urban geosystem, its spatial and structural heterogeneity, and its functional systems, which in turn can only be achieved by supporting the research process with accurate and reliable information resources. In this regard, the possibilities offered by the proposed methodological scheme for efficient geospatial registration of SUHI variations at the microscale, including the calculation of intra-urban SUHI intensity, are discussed in detail. The methodology builds on classical approaches for using local climate zoning (LCZ), adding capabilities for precise delineation of individual zone types and for geostatistical characterization of the urban surface heat island (SUHI). Finally, the proposed scheme is based on state-of-the-art technological tools that provide flexible and automated capabilities to investigate the phenomenon at microscales, including by enabling flexible observation of its dynamics in terms of heat wave manifestation and evolution. Results are presented from a series of sequential tests conducted on the largest residential area in Bulgaria’s capital city, Sofia, in terms of area and population, over a relatively long period from 2021 to 2024.

Medicinal plants collected by visitors in protected areas in Bulgaria

Abstract This survey is a part of a broader ethnobotanical research conducted amongst visitors of protected areas in Bulgaria. The aim of the present study was to find out which herbs are collected by the visitors. Two types of interviews were conducted – among visitors of the Shumen Plateau Nature Park and among users of social network Facebook. Only small proportion from both groups collected medicinal plants from the visited areas. On the other hand, their answers revealed the knowledge about the most used medicinal plants in Bulgaria. Notably, most of them specify, that they comply with legal requirements and that the collected herbs are for personal use only. There are some differences between two groups – a smaller proportion of the online group collected medicinal plants from natural habitats, but demonstrated a greatest knowledge than the visitors of the Shumen Plateau Nature Park. Reported medicinal plants by the respondents are widely distributed in Bulgaria. Two endangered species have been mentioned: Aesculus hippocastanum L. and Sideritis scardica Griseb. Four medicinal plants were cited from both groups: – Hypericum perforatum L., Thymus sp. div., Tilia tomentosa Moench and Rosa canina L. Results revealed also the major disadvantages of the online surveys – skewed respondents, as only people interested in using herbs participate in the survey.

SATELLITE MONITORING OF DRAGOMAN MARSH FOR THE PERIOD 2018-2023

In this study, monitoring of the Dragoman Marsh was conducted for the period 2018-2023. The Dragoman Marsh is distinguished as the largest natural karst wetland area in Bulgaria. Monitoring of this natural formation is essential for studying its dynamic processes and ensuring its protection. The use of satellite data represents a key tool in this context. The data from the Sentinel 2 satellite being utilized for this purpose. Following appropriate processing of this data, classification of the object by years and seasons - spring and summer-autumn - was performed, using indices such as NDVI, NDWI, and TCT based index - NDGI. The obtained results contribute to a better understanding of the development of the wetland area and provide guidance for its conservation and management.

E-SMART Assessment for Rural Areas (Case Study of Veliko Tarnovo Region, Bulgaria)

Abstract The research topic is motivated by the fact that rural areas in Bulgaria are lagging behind in their economic, social and territorial development compared to urban areas, despite European Union support policies for regional development and cohesion. Regardless of the fact that more and more the specialized literature investigating the development of rural areas emphasizes multifaceted factors, including environmental, social and technological aspects, there is a lack of a complex approach to analysis and assessment of their condition. Therefore, the authors set out to develop and demonstrate the application of a comprehensive E-SMART evaluation model based on a combination of 6 groups of factors with a significant impact on the socio-economic development of rural areas. The approbation of the toolkit was carried out in the seven rural municipalities in the Veliko Tarnovo region. The analysis of the results of the groups of factors – economic, social, manufacturing, agriculture, resources and technologies, as well as the complex indicator E-SMART-score, reveals the general and specific problems, as well as the competitive advantages of the rural areas included in the analysis. E-SMART model can be used as a reliable tool to increase the administrative capacity of municipalities when making strategic decisions for the development of the region.

Detection of Leishmania infantum Antibodies in Stray Dogs from Nonendemic Areas in Bulgaria.

Background: Leishmaniasis is a zoonotic protozoan infection which is endemic in parts of Europe. Dogs are commonly affected by Leishmania infantum and are regarded as the main reservoir for humans' infection. Sporadic human cases are reported annually, mainly from the endemic south part of Bulgaria. However, no recent data on canine leishmaniasis geographical distribution in Bulgaria have been published. The aim of this study was to investigate the current seroprevalence rate of L. infantum in stray dogs from areas where this infection was not previously reported. Results: The estimated overall seroprevalence rate was 8.3% (95% confidence interval [CI]: 2.6-14.0) with no significant difference between the two examined districts [χ2 (1, N = 90) = 0.32, p = 0.69]. In Sofia, the seropositivity was 7.2% (95% CI: 0.9-13.5) and in Sofia (stolitsa) 11.0% (95% CI: 0-23.0). No association between sex and serological status [χ2 (1, N = 90) = 1.83, p = 0.27] and age and seropositivity [χ2 (2, N = 90) = 1.98, p = 0.52] was detected. High levels of antibodies (fourfold increase from the assay's cut-off) were observed in half of the positive dogs.

SRAP markers for characterization of the genetic diversity and differentiation of Pinus nigra populations in protected forested areas in Bulgaria, Greece, and Cyprus

The present study aimed to evaluate the genetic diversity and differentiation of Pinus nigra Arnold, the European black pine, populations located in protected forested areas in three countries from the Balkan and Mediterranean region: Bulgaria, Greece, and Cyprus. Totally, 175 DNA samples from P. nigra plants collected from eight populations in these countries were analyzed using three SRAP primer pairs. The applied SRAP markers demonstrated high-resolution power, resulting in the identification of an average of 215 ± 67 polymorphic loci per SRAP primer pair. The analysis of molecular variance (AMOVA) showed that 82% of the observed variation was due to intra-population variation, while 18% was due to inter-population variation. The overall analysis of the population structure suggested low (Fst ≤ 0.01) intra-country differentiation for the populations from Bulgaria and Cyprus and moderate (0.15 ≤ Fst ≤ 0.17) inter-country differentiation. On the contrary, high differentiation between the populations (0.06 ≤ Fst ≤ 0.20) and complex genetic structure were characteristic of the three populations from Greece, relatively closely located in the area of the Pindos National Park. Analysis of the population structure also revealed that one of the Pindos populations belonged to the cluster of Bulgarian populations (Fst ≤ 0.01), showing moderate (Fst ≤ 0.11) to high (Fst ≤ 0.20) genetic differentiation from the other analyzed Pindos populations. The further use of SRAP markers for mapping the genetic diversity among P. nigra populations and identification of local populations diverted from the overall phylogeography-driven pattern in the studied region are discussed.

CONDITION, PROBLEMS AND PERSPECTIVES OF THE LABOR FORCE IN RURAL AREAS OF BULGARIA

The specific features in the socio-economic development of rural areas in Bulgaria are the basis of non-uniform processes and trends in the formation of local labor force contingents. Based on data from the population and housing censuses conducted in 2011 and 2021, the dynamics of the labor force in rural areas of Bulgaria, as well as its structure by age, gender and education, are analyzed in this study. The research aims to outline the regions with the most serious problems with the reproduction of the labor force through a comparative analysis of the potential of the labor force in rural areas, urban areas and the average level for the country. Emphasis is placed on the impact of changes in the age structure of the working-age population (aging) on the general level of activity, as well as the degree of demographic and economic burden on the labor force throughout the study period. The changes in the structure of the labor force in rural areas are examined in detail and the prospects for the reproduction of the labor force in the short term are outlined. Based on the conclusions, some of the problems facing the effective use of the available labor force in rural areas were analyzed and recommendations were formulated regarding the necessary and adequate changes in the demographic policy, to promote the birth rate and retain a young labor force in the local labor markets. Keywords: Labor force, aging, unemployment, demographic reproduction, rural areas JEL: J20; J21; Е24

Valuation of the Quality Level of Bulgarian Tobacco from the Market Sector of “Basmi” Variety Group

The aim of the current study was to assess the quality level of Oriental tobaccos from the market sector of the “Basmi” variety group from different production areas in Bulgaria. Tobaccos from Krumovgrad and Greek Basma ecotypes (varieties “Krumovgrad 90”, “Krumovgrad 58”, “Krumovgrad 78”, and “Basma”, respectively) were investigated, all farmer-produced (2019 crop year) in seven tobacco regions. The investigation followed a procedure validated for monitoring the quality of Bulgarian tobaccos, incorporating four evaluation steps – chemical indices of tobacco and tobacco smoke, expert and smoking assessment, and final rating by a complex quality index. Statistically significant differences were observed between the compared tobaccos (variety and region based) within the two ecotypes. For Krumovgrad ecotype, the final rating of the compared tobaccos revealed the best complex quality indicators in varieties “Krumovgrad 78” from Kardzhali (micro-region Patitza), “Krumovgrad 58” from Haskovo-Harmanli (Stambolovo) and “Krumovgrad 58” from Ivaylovgrad (Belopoltzi). With the best quality level within ecotype Basma were the tobaccos produced in Svilengrad (micro-region Raykova mogila) and Momchilgrad (Chorbadzhiysko) regions. The results from the study substantiate the annual monitoring of the quality level of Bulgarian Oriental tobaccos and provide data, which have potential importance for the national tobacco sector.

Modeling the Shadow Economy. Why Does the Bulgarian Carry out Undeclared Employment?

The shadow economy is a complex phenomenon that impacts all aspects of one country’s economic system. One theory explaining the emergence of the shadow economy holds that it results from the breach of the civil contract and serves as the individual’s response to the inefficiency of the state’s institutions. On its part the shadow economy has a negative impact on the state budget and is able to distort basic indicators such as growth, unemployment, real GDP. That’s why it is important for policy makers to know what the reasons for such behavior are. Using information from a survey of people in all areas of Bulgaria, conducted in early 2020, this article explores the primary causes of Bulgarians’ participation in shadow economic activities, specifically in undeclared labor. Via linear and afterwards probit binary regression the article ascertains each respondent’s inclination to participate in set activities based on their responses to a question asking why they believe some persons in their sector of employment opt to get some of their payment “in hand.” The findings are in favor of authorities and managers, because knowing the main drivers of the shadow economy, they can take measures aimed directly at the causes of such behavior.

First report of root rot caused by Pythium aphanidermatum on industrial hemp (Cannabis sativa L.) in Bulgaria

Worldwide, thegrowers suffer serious losses from mycoses caused by Pythium, Rhizoctonia, and Fusarium. Due to the root rot disease, the whole plant dies, regardless of the phenophase at the moment of infection. The increase in Cannabis sativa acreage in Bulgaria and the accompanying problems associated with the severity and incidence of various diseases necessitated this study. The study aimed to survey the root rot symptoms on field and greenhouse plantations and monitoring the plant`s health status of cannabis-planted areas in Bulgaria during 2021-2022. The main problem was darkening at the base of the stem, yellowing, dieback, and wilting of whole plants from the seedling stage to flowering. Following the Koch's postulates and morphological characteristics by microscopic observation, all collected samples corresponded to genus Pythium. For complete identification, a molecular diagnostic was performed with primers ITS1 and ITS4 using four isolates from different regions of the country, which confirmed Pythium aphanidermatum as the causative agent. Based on the molecular analyses, this is the first report of root rot caused by Pythium aphanidermatum on cannabis in Bulgaria. Keywords: Pythium aphanidermatum, root rot, Industrial hemp, Cannabis sativa

Benefits for visitors provided by protected areas in Bulgaria and willingness to become a conservation volunteer

Protected areas in Bulgaria (PAB) provide valuable ecosystem services. Maintaining of ecosystem health is of great importance for human wellbeing. The environmental volunteering is a valuable tool in solving local ecological problems. The main objective of the present research was to identify ecosystem services offered by PAB and attitude to participation in conservation volunteering using online survey and face-to-face interviews. Most respondents regularly use ecosystem services offered by PAB. Being well-informed about significance of maintaining ecosystem health, a lot of them declared willingness to become conservation volunteers. Online surveys could be used not only for data collection, but as also as a tool to involve people in environmental protection.

Scenarios for the Demographic Development of Rural Areas in Bulgaria – 2027

The ongoing demographic crisis in Bulgaria (permanent depopulation, constant reduction and deterioration of the age structure of the rural population, etc.) increasingly encourages policies to strengthen the social, ecological, economic, and managerial sustainability of rural areas. The aim of this study is to forecast the socio-demographic trends of rural areas in Bulgaria for 2027. Based on a developed linear scenario model, the sensitivity of selected indicators is identified under certain assumptions of changes in the independent variables. The suggested optimistic scenarios for the selected indicators have the highest rating, which means that certain favorable changes in demographic and socio-economic aspects should be expected in rural areas. One of the lowest ratings is for the pessimistic scenario of the index by place of residence, which indicates an expectation for a moderate preservation of the existing trend of population reduction. The forecast is that at the end of 2027, child mortality will decrease, due to the continuation of the tendency to decrease the average age of the mother at the birth of a child, an increase in the birth rate and fertility among women.

Factors of the Regional Dynamics of the Newly Built Residential Area in Bulgaria for the 2005 – 2021 Period

Residential construction, as part of the construction sector, has developed quite dynamically over the last twenty years. This paper examines the dynamics of new housing construction over a seventeen-year period. The panel dataset includes household-related factors of demographic, social, and economic character regarding the demand for newly built housing estate. Different specifications of econometric panel models for the dynamics of new housing construction at district level in Bulgaria are built and estimated. The results show that the dependence of housing area of newly built dwellings by regions in Bulgaria is directly proportional to natural increase, migration, average annual wage, and number of pupils, and inversely proportional to unemployment. Interestingly, the variable “net enrollment rate of children in kindergartens” did not show the expected effect on the growth of newly built housing.

Flood risk assessment in urban areas in Bulgaria

Flooding is a phenomenon that cannot be prevented. Some human activities, such as the growth of settlements and economic assets in the floodplains, as well as the declining natural capacity of the soil to retain water caused by land use and climate change, are key factors in increasing the likelihood of floods and their adverse effects. The study is based on the data published in the National Statistical Institute Annual Reports, aiming to analyse and summarise the cases of floods in the urban areas in Bulgaria. The flood risk in the country in the period 2007-2021 is assessed for the urban areas near 17 hydrometric stations (HS). The flood index K is used to determine the areas with the highest sensitivity to floods as well as to extreme floods with significant adverse effects. The results have shown that only particular areas occasionally show high sensitivity to floods. As an average, however, for the study period, there is no area (HS) with river basins that are very sensitive to floods (K≥0.3) for the investigated period (2007-2021). Seven of the nineteen HS are sensitive to floods: Glozhene (HS2), Targovishte (HS6), Varna (HS8), Sofia-Orlandovtsi (HS12), Yambol (HS15), Burgas (HS17) and Kardzhali (HS19).

The Privileges of Bulgarian Writers at Bulgarian Resorts during the Second Half of the 20th Century: Literary Interpretations and Contextualizations

The article examines the formation of the special resort as a topos in which the pro-cesses of construction and functioning of literary texts were activated in the time of social realism, when privileges and benefits were created for special category of writ-ers. The process began with the formation of the Union of Fighters Against Fascism and Capitalism and grew with the special writers' awards given out on various occa-sions. The preferential use of recreational areas in Bulgaria also creates a kind of zoning - Borovets, Sozopol, Hisarya (Villa "Petrovich"), Varna, "Golden Sands" and others are assigned to Union of the Bulgarian Writers. In this context, literary collec-tions of short stories, novels, literary legends, etc. are compiled. The main thesis of the research is that resort-themed works combine ideology and literature while seemingly maintaining their tolerance for dominant socio-ideology. At the same time, they form a layer of relative freedom and are a peculiar escape from the cruel reality of the totali-tarian state. For the purpose of the report, the normative base (laws, rules, regula-tions, etc.) for the period 1944-1965, as well as memories, letters, journalistic materi-als, archives, works of fiction, are studied.

SPATIAL DISTRIBUTION OF IRRIGATED AREAS BY PLANNING REGIONS

The main objective of the paper is to analyse the spatial structure of irrigated areas by planning regions and by categories of the utilised agricultural area in Bulgaria. Statistical data from the census of agricultural holdings were used for the empirical study, and from a methodological point of view, the correspondence analysis was applied. The results of the research can be used in the preparation of regional strategies covering the possibilities of mitigating the effects of climate change on Bulgarian agriculture through irrigated agriculture

EDUCATIONAL SYSTEM AND RESULTS IN PERIPHERAL RURAL AREAS – STATUS AND PERSPECTIVES

The EU Rural Vision 2040 assumes that skilled, educated and motivated people will be in rural areas to make them stronger, connected, resilient and prosperous. The paper aims to look deeper in the status of the school educational system and its results in the peripheral rural areas in Bulgaria and into their perspectives to respond and benefit from the EU Rural Vision policy initiative. The results urge the educational, rural and regional development policy makers to undertake specific and targeted actions to address the school educational gap in the peripheral rural areas

Drought Monitoring Using Remote Sensing Data

The paper deals with the application of the remote sensing for drought monitoring. A way of their application in practice are shown through example for monitoring of drought that is done for three different area in Bulgaria with different pattern, for the same time (July) and for eleven randomly selected years from 1994 to 2009. For the purpose, NDVI, LAI and FPAR vegetation indexes are used. According to Intergovernmental Panel on Climate Change (IPCC) drought and floods are the most severity events threatening the country so attention is paid on drought monitoring.