Northeastern Bulgaria Research Articles

Prevalence of Intestinal and Non-intestinal Parasitoses in Varna region for 2013-2015 year: data from outpatient parasitological testing.

Introduction and aim: The objective of this study is to determine the structure of the outpatient parasitology tests and the epidemiological significance of the resultant morbidity for intestinal and non-intestinal parasitic diseases in Varna region, Northeastern Bulgaria. Materials and methods: A total number of 30 687 patients tested for human parasites were investigated. Statistical analyses were performed regarding the proportion of the tests by indications and the consequential prevalence of parasitic diseases was estimated. Results: The main percentage of outpatient tests is performed with prophylactic purposes (91.38%), followed by clinical (7.67%) and epidemiological (0.95%) indications. Significant concern represents the discovered prevalence of parasitic diseases with person-to-person and food-borne routes of transmission in children (Enterobiosis – 1.18%, Giardiasis – 0.78%) and in the active adult population (Giardiasis – 0.75%, Enterobiosis – 0.59%). The higher extensity of the diseases with other mechanisms of transmission (Echinococcosis -26.15%, Toxoplasmosis -16.69% and Trichomonosis – 9.57%) are a result of their specific symptomology. Conclusions : Due to the asymptomatic course intestinal parasitic diseases are found predominately via prophylactic screening. In current conditions of increased migration processes this hidden morbidity in the adult population continues to represents a significant epidemiological risk.

Flint tools processing and use in northeastern Bulgaria at the end of Late Neolithic

A Late Neolithic settlement, chronologically related to the Boyan-Bolintineanu culture, with a considerate collection was found in 2003 during excavations of a Thracian fortress of IV-III BC in the archaeological reserve of Sboryanovo, northeastern Bulgaria. The total number of flint objects discovered to date is 1628. Over 90% of the raw flint is yellowish-grayish spotted flint with many inclusions, cracks and defects, apparently originating from small nodules collected on the surface and in the riverbeds. The remainder is typical Ludogorian (Balkan) honey-colored flint with excellent quality characteristics. The overall ratio of waste production: tools is typical for the Neolithic and Chalcolithic settlements in the area. The type of tools, use-wear traces, methods of treatment and the raw material used are specific for the Neolithic period. The analysis of the raw material used and the method of processing indicated trends in production, resulting in the subsequent bloom of flint industry in the Chalcolithic of the Balkan-Danubian region.

BIOLOGICAL DIVERSITY OF MYRIAPOD COMMUNITIES (DIPLOPODA, CHILOPODA) ON THE MADARA PLATEAU, NORTH-EASTERN BULGARIA

The assessment of the biodiversity of natural complexes has a significant practical application and can be used as a sample for the analysis of the role of environment in the spread and bio-geographic distribution of species, the models of faunogenesis and the establishment of the specific biota. The aim of this research is to study the α- and β-diversity of millipede and centipede communities in the various habitats along the Madara Plateau, North-eastern Bulgaria. The material for the analysis was collected through pitfall traps, arranged in lines of ten on eleven sampling plots, which have been reported on a monthly basis in the period June 2012 - February 2015. A total of 3415 myriapods have been collected – 2776 millipedes of 12 species and 639 centipedes of 16 species. The millipede communities feature higher diversity in species and a comparatively higher degree of equality compared to those of the centipede communities. The forest habitats along the Madara Plateau are characterized with high diversity of millipede communities, while the open areas are the preferred habitat of Chilopoda.

Factors affecting nurses` intention to emigrate from the country in the context of the satisfaction with employment situation

Introduction : Healthcare professionals` high turnover in our country is an especially topical issue within modern conditions. The reasons behind this ongoing process are largely due to nurses` emigration. Thus, the main task of healthcare managers is to focus their efforts on identifying the factors affecting the attitude of nurses to emigrate abroad. Materials and methods: For the purpose of an empirical sociological study, in February - April 2014 a direct individual anonymous survey on health professionals` motivation to emigrate abroad was conducted. The opinions of 413 nurses from a university and hospitals for active treatment in Northeastern Bulgaria were included in the survey. A total of 11 types of departments and clinics, characterized by high intensity workflow, were studied. Deliverables: The results of this analysis indicate significant emigration potential among surveyed nurses. Those who are willing to leave the country are highly educated younger nurses, whose point of view is influenced by personal professional experience. The intention to practice the profession abroad is significantly motivated by various aspects of work satisfaction. Discussion: Similar to our results, a number of authors in their studies report data revealing the intention to work abroad of predominantly young professionals seeking higher payment and better perspectives for career development. Conclusion : The results demonstrate significant emigration potential among the nurses participating in the survey. Among the individual factors, those which clearly affect the intention to emigrate are professional experience, age and level of educational degree. Work satisfaction compared to experience and age has stronger influence on nurses` attitudes to seek alternative opportunities to work outside the country.

PRELIMINARY STUDIES ON THE EXPERIMENTAL RESEARCH OF THE EFFECTIVENESS OF THE USE OF GEO-INFORMATION MODELS IN THE AREA OF THE RIVER GOLIAMA KAMCHIA

Preliminary studies were necessary to ensure that the experimental research to demonstrate the effectiveness of the technology and the geo-information model were carried out in North-Eastern Bulgaria, along the river Goliama Kamchia.

Depositional environment, organic matter characterization and hydrocarbon potential of Middle Miocene sediments from northeastern Bulgaria (Varna-Balchik Depression)

AbstractThe depositional environments and hydrocarbon potential of the siliciclastic, clayey and carbonate sediments from the Middle Miocene succession in the Varna-Balchik Depression, located in the south-eastern parts of the Moesian Platform, were studied using core and outcrop samples. Based on the lithology and resistivity log the succession is subdivided from base to top into five units. Siliciclastic sedimentation prevailed in the lower parts of units I and II, whereas their upper parts are dominated by carbonate rocks. Unit III is represented by laminated clays and biodetritic limestone. Units IV and V are represented by aragonitic sediments and biomicritic limestones, correlated with the Upper Miocene Topola and Karvuna Formations, respectively. Biogenic silica in the form of diatom frustules and sponge spicules correlates subunit IIa and unit III to the lower and upper parts of the Middle Miocene Euxinograd Formation. Both (sub)units contain organic carbon contents in the order of 1 to 2 wt. % (median: 0.8 for subunit IIa; 1.3 for unit III), locally up to 4 wt. %. Based on Hydrogen Index values (HI) and alkane distribution pattern, the kerogen is mainly type II in subunit IIa (average HI= 324 mg HC/g TOC) and type III in unit III (average HI ~200 mg HC/g TOC). TOC and Rock Eval data show that subunit IIa holds a fair (to good) hydrocarbon generative potential for oil, whereas the upper 5 m of unit III holds a good (to fair) potential with the possibility to generate gas and minor oil. The rocks of both units are immature in the study area. Generally low sulphur contents are probably due to deposition in environments with reduced salinity. Normal marine conditions are suggested for unit III. Biomarker composition is typical for mixed marine and terrestrial organic matter and suggests deposition in dysoxic to anoxic environments.

Multi-proxy records of Holocene palaeoenvironmental changes in the Varna Lake area, western Black Sea coast

High-resolution spore-pollen analysis of laminated sediments of newly taken Core-3 (870 cm long) from Varna Lake (northeastern Bulgaria) is combined with multiproxy micropalaeontological analyses of dinoflagellate cysts, acritarchs, and other non-pollen palynomorphs (NPP), including fossil algal and fungal remains. The location of the core is close to several submerged praehistorical sites and the Varna Chalcolithic Necropolis, and permits more precise palaeoecological correlations of obtained results with available archaeological and geochronological data. The established Age vs. Depth Model shows that the formation of the lake started after 7870 cal. BP due to a rise of the Black Sea level, also known as the First Phase of the Vityazevyan Black Sea Transgression. After ca. 94 y, the Second Phase of the Vityazevyan Black Sea Transgression is registered by a major change in the sedimentation and formation of molluscan shell hash layer of Mytilus galloprovincialis that covers the interval 7776 to 6183 cal. BP. Mixed oak and hornbeam forests dominated the vegetation cover during the Atlantic, Subboreal and Subatlantic chronozones of the Holocene. An important change in the forest composition occurs at ca. 5518 cal. BP, when Carpinus betulus reached its maximum spread due to a climate change. The high-resolution geoarchaeological reconstruction of palaeovegetation also reveals the extent of anthropogenic influence in the Varna Lake area, with deforestation and agricultural practice. Two periods of significant presence of pollen from cultivated cereals, and secondary anthropogenic indicators (weeds and ruderals) were identified. According to the available AMS-radiocarbon data, these periods correspond to the Late Eneolithic and Early Bronze Age. The Transitional period without human activities between these two archaeological periods lasted ca. 319 y and coincides with a rise of the Black Sea level, reflected by the increase of euryhaline marine dinoflagelate cysts Lingulodinium machaerophorum and Spiniferites belerius, and acritarchs Cymatiosphaera globulosa and Micrhystridium cf. ariakense during the First Phase of the Kalamitian Black Sea Transgression. The increased values of Corylus coincidently with decrease of Quercus and Ulmus suggest clearance of forests and enlargement of arable areas during the Late Eneolithic. The NPP-record of spores of coprophyllous fungi Cercophora, Sordaria, Podospora and Chaetomium indicates the presence of domestic animals during the Early Bronze Age. The maximum of Alnus, Ulmus, Fraxinus excelsior-type and Fagus pollen at 717 cal. BP suggests an increase of humidity and cooling of climate during the Subatlantic.

Middle Devonian (Givetian) supratidal sabkha anhydrites from the Moesian Platform (Northeastern Bulgaria)

The Middle Devonian (Givetian) anhydrites from deep wells in the Moesian Platform (Northeastern Bulgaria) are commonly distinguished into nodular and contorted structures. The latter includes a great variety of non-bedded (nodular, nodular-mosaic, mosaic and mosaic to massive), bedded (bedded nodular, bedded nodular-mosaic and bedded-mosaic to massive) and distorted (distorted nodular-mosaic, distorted mosaic, distorted bedded-mosaic, and “ropy bedded”) types. Microscopically, the anhydrite types are characterized by felted, subfelted and microcrystalline (aphanitic) microfabrics. The associated carbonate lithofacies and the synsedimentary/early diagenetic anhydrite features suggest that these sediments were formed in an arid peritidal setting with well distinguished subtidal (ostracod mudstones and wackestones, paleosiphonoclad wackestones and packstones and ostracod-peloidal packstones and grainstones), intertidal (microbial mats) and supratidal (sabkha anhydrites) zones. The described nodular and contorted anhydrites are interpreted as originated by similar mechanisms as those operating in recent sabkha settings in the Arabian Gulf. Most probably, they are the result of replacement/displacement intrasediment sulphate growth within the vadose and upper phreatic zones of the supratidal sabkha. The various nodular and contorted types are regarded as formed from incipient nodular structure and represent different stages of anhydrite nodule enlargement and growth deformation due to additional sulphate accumulation in the supratidal zone.

Terrestrial gastropods of Srebarna Nature Reserve, North-Eastern Bulgaria (Gastropoda).

We give the results from the first investigation focused on the land snail fauna in Srebarna Nature Reserve in Bulgaria. A total of 23 localities were studied and 27 species of terrestrial gastropods were found, 23 of which were new observations for the Reserve.

Air temperature and precipitation variability in northeastern Bulgaria on the background of climate change

The aim of the present research work is to bring to better understanding the recent climate change at regional scale. The tendencies of many-years variability of air temperature and precipitation in Northeastern Bulgaria are determined. In order to determine future tendencies in air temperature and precipitation variability the data from regional climate models are analyzed. The occurrence of extreme monthly temperature and precipitation totals are investigated by calculation of 10 and 90 percentiles of the empirical distribution in the reference period 1961-1990. The main result of present work is that there are a positive tendency in changes of air temperature and negative in precipitation. The regional climate model data show increasing of extreme hot and dry months which is considerable for the second part of 21 century.

Mitochondrial DNA Suggests a Western Eurasian Origin for Ancient (Proto-) Bulgarians.

Ancient (proto-) Bulgarians have long been thought of as a Turkic population. However, evidence found in the past three decades shows that this is not the case. Until now, this evidence has not included ancient mitochondrial DNA (mtDNA) analysis. To fill this void, we collected human remains from the 8th to the 10th century AD located in three necropolises in Bulgaria: Nojarevo (Silistra region) and Monastery of Mostich (Shumen region), both in northeastern Bulgaria, and Tuhovishte (Satovcha region) in southwestern Bulgaria. The phylogenetic analysis of 13 ancient DNA samples (extracted from teeth) identified 12 independent haplotypes, which we further classified into mtDNA haplogroups found in present-day European and western Eurasian populations. Our results suggest a western Eurasian matrilineal origin for proto-Bulgarians, as well as a genetic similarity between proto- and modern Bulgarians. Our future work will provide additional data that will further clarify proto-Bulgarian origins, thereby adding new clues to the current understanding of European genetic evolution.

Atmospheric Patterns During the Storms from January 2014 in Bulgaria and Romania

Abstract Synoptic conditions associated with strong winds and snowfalls on January 2014 in Bulgaria and Romania are investigated in this paper. The Romanian authorities established the orange and red codes while the Bulgarian ones the orange code. A first peak was recorded in northern and especially northeastern Bulgaria and south-eastern Romania on January 25-26 and a second one on January 29 2014. The purpose is to understand what regulates the duration and intensity of these events. For their study, NCEP-500/700/850 and SLP analyses, different model outputs and soundings as well as data from 12 weather stations have been used.

Chert raw materials and artefacts from NE Bulgaria: A combined petrographic and LA-ICP-MS study

In the present study two analytical methods are applied to characterize chert artefacts and raw materials from northeastern Bulgaria (Ludogorie region): petrographic observation and laser ablation inductively coupled plasma mass spectrometry). Archaeological samples from 12 Chalcolithic sites from Bulgaria are analyzed as well as raw material from 6 outcrops in northeastern Bulgaria are identified and documented during a survey in 2012 when many raw material samples were collected. The chert raw material mostly occurs in various Quaternary secondary deposits, originating from destruction and disintegration of the Lower Cretaceous (Aptian) limestones in the area. The paper is aimed at tracing the provenance of the artefacts based on their petrographic characteristics and geochemical composition. The archaeological evidence shows a wide distribution of the Ludogorie chert throughout the country. On the basis of micropetrographic observations, Gurova and Nachev (2008) described two main chert types (Ravno and Kriva Reka). Our petrographic study confirmed the previous results and an additional chert type was distinguished, originating from primary and secondary deposits (quarries in Koprivetz and Krasen villages) and is represented by silicified limestones (bioclastic-peloidal packstones or grainstones). It is noteworthy that the first two types of chert were largely used for prehistoric artefact manufacturing while the last one is not attested among studied assemblages at all.

24. Varna Lake (north-eastern Bulgaria): vegetation history and human impact during the last 8000 years

24. Varna Lake (north-eastern Bulgaria): vegetation history and human impact during the last 8000 years

Multiple Wormian bones and their relation with definite pathological conditions in a case of an adult cranium.

Wormian bones, also known as intrasutural bones, are present as an anatomical variation in healthy individuals. However, a higher than the usual incidence can be an important feature of some congenital pathological conditions. In this study we describe a case of an adult cranium with multiple Wormian bones. The cranium was a single sample obtained from an archaeological excavation in Vinitsa, Northeastern Bulgaria, and probably dated in the Chalcolithic. The Chalcolithic is a period of human history connected with discovering and using of copper. Actually, it is a transitional phase between the Neolithic and the Bronze Age. In this case the Wormian bones are mostly large in size and arranged in a mosaic pattern in several cranial regions. The cranium also shows features such as dolichocrany, a moderate platybasia, a notch in the posterior margin of the foramen magnum, hypoplastic and asymmetrical frontal sinuses, underdeveloped mastoid air cells, hyperostosis cranii interna, moderate frontal bossing, a complete metopic suture, a delayed sutural closure, relatively small facial bones, an early loss of teeth, dental caries and hypoplastic enamel defects on two preserved molars. Differential diagnosis indicates that the combination of all these features shows a link with pathological conditions involving dysplasias with prominent membranous bone involvement and an increased bone density such as cleidocranial dysplasia and pyknodysostosis.

P-0170 - Epidemiology of Rectal Cancer in the Regions of Varna and Dobrich, Bulgaria

Introduction: Incidence and prevalence rates of rectal cancer continuously grow in Bulgaria in spite of the various preventive campaigns. The objective of this study was to analyze the annual dynamics of several demographic and clinical parameters of rectal cancer in two regions in North-Eastern Bulgaria served by the Specialized Oncologic Hospital of Varna. Methods: An epidemiological analysis of data from patient's registry of the Specialized Oncologic Hospital of Varna for 2004-2013 as well as from ‘Cancer Incidence in Bulgaria’, the official publication of the National Centre of Oncology of Sofia for 2004-2010 concerning the patients from the regions of Varna and Dobrich was carried out. Results: Both incidence and prevalence rates of rectal cancer in both genders and most age groups increased. Cancer incidence rate of male rectal cancer in the region of Varna increased from 26.8 in 2008 to 32.4 in 2013 while that of female one - from 14,9 to 22.3 per 100000, respectively. The corresponding figures concerning the region of Dobrich were the following: 14.8, 21.5; 9.6 and 14.7. In 2010, the region of Varna was fourth among all 30 regions in Bulgaria concerning the age-adjusted (world standard) incidence rate of female rectal cancer per 100000 and fifth concerning that of male one. There was a gradual increasing of the number and percentage of the newly-diagnosed rectal cancer cases during this period in both regions. The percentage of the early-diagnosed cases in the region of Varna increased from 41.7% in 2012 up to 49.2% in 2013 while that in the region of Dobrich did from 54.3% up to 54.5% only. All the newly-diagnosed cases were morphologically verified. In 2004-2008, males aged between 61 and 70 years and females aged between 71 and 80 years (35.65% and 30.47% of the cases, respectively) were most commonly affected. In 2009-2013, both male and female patients aged between 61 and 70 years (35.73% and 37.50% of the cases, respectively) were most affected. As a whole, this age group was most affected followed by the age group between 71 and 80 years (34.37% and 29.43% of the cases, respectively). It was an alarming fact that four patients were aged up to 30 years only and 17 ones were aged between 31 and 40 years. Male patients' mean age was similar (65.82 and 65.47 years) during these two periods while female patients' one slightly increased during the second period (from 66.91 to 67.77 years). In 2009-2013, radical surgical treatment was performed in 58.33% of the patients. The age-adjusted (world standard) mortality rate slightly decreased during the recent years for both genders in Bulgaria and in these two regions as well. Conclusion: Our results revealed a relatively unfavourable socio-epidemiological picture of this disease. Despite the continuous improvement of the diagnostic capacities, surgical opportunities and preventive programs for rectal cancer in Bulgaria, this malignancy is still widely disseminated. Its prognosis remains relatively poor.

Holocene palaeoecology and human–environmental interactions at the coastal Black Sea Lake Durankulak, northeastern Bulgaria

The environmental changes (vegetation history, human impact and land use, influence of the Black Sea) in the area of Lake Durankulak, northeastern Bulgaria, were reconstructed and synthesized for the last ca. 8000 years. The palaeoecological information derived from various proxies (pollen, plant macrofossils, molluscs, sediments) was compared on a regional scale with the evidence from the nearby coastal lakes Shabla–Ezeretz and Bolata. The Early Holocene xerothermic steppe vegetation, dominated by Chenopodiaceae, Artemisia and Poaceae species, and accompanied by stands of trees in moister habitats, was transformed after 6000 cal. BP into a forest-steppe, comprising oak woods with Carpinus betulus, Ulmus, Tilia, Acer. This vegetation pattern has been periodically modified, depleted and replaced by arable land or xerothermic herbaceous communities enriched with anthropophytes and ruderals, particularly after the intensification of human activities since 3300 cal. BP. The archaeobotanical evidence from the region has provided valuable information about the occupation phases and subsistence strategy of the local people since the Late Neolithic (5300 cal. BC/7250 cal. BP). Periods with cultivation of cereals (Triticum, Hordeum) and/or stock-breeding activity were interrupted by abandonment of the settlements and the arable land due to unfavourable environmental changes. The periodical connection/isolation of Lake Durankulak with the Black Sea and the periods of marine influence were recorded by changes in the composition of the fossil molluscan fauna and the lithology of the sediments, and chronologically confirmed by radiocarbon dates. The development of the coastal lakes throughout the largest part of the Holocene has been also considerably influenced by the fluctuations of the Black Sea level.

Some Paleopathological Cases from a Medieval Necropolis of Drustar (Silistra), Bulgaria (Investigation of the Postcranial Skeletons)

Drustar was a medieval town in Northeastern Bulgaria. It was the most important fortress in the Lower Danube. The bone material was excavated from a necropolis situated near to the north wall of the fortress. The burials were dated in 9th – 15th century AD. The study included postcranial skeletons of 147 individuals (42 children and 105 adults). There were observed traces of pathological changes in the different bones of the postcranial skeleton, such as fractures, osteoarthritis, spina bifida, etc. The degenerative disorders of the joints were most often occurred. The results obtained suggest that living conditions were not very favourable for the medieval population of Drustar. DOI: 10.5901/mjss.2013.v4n11p603

Paleopathological Findings in Cranial Series from a Necropolis of a Medieval Town of Drustar (Silistra), Bulgaria

The comprehensive study of the various paleopahological findings on bone material is of great importance for the biological reconstruction. It is also a valuable source of information about the way of life of the past populations. In this study we described some paleopathological findings on cranial series obtained from archaeological excavation of a necropolis of the medieval town of Drustar (9th-15th century), Northeastern Bulgaria. Drustar was the most important Bulgarian fortress of the lower Danube. This town was connected with the earlier history of Bulgaria since it was one of the first places in which the Slavic people and the Bulgars were settled after they passed over Danube. The town was also an inheritor of the Roman town Durostorum, called Dorostol from the Byzantines. From the Ottoman period in Bulgaria till today the town bears the name Silistra.The investigated cranial series includes a total of 196 crania (70 male, 50 female, 59 infant, and 17 unidentified). There are two cases of traumas inflicted as a probable result of battle injuries in adult male individuals. In a few individuals is observed cribra orbitalia as an evidence of anemia. Concerning the jaw and tooth pathology the most common findings were the dental caries with related complications. There are also some cases of alveolar atrophy in adult individuals and cases of temporomandibular joint arthritis as well. DOI: 10.5901/mjss.2013.v4n11p640

The impact of the drought on the main crops cultivated in Northeastern Bulgaria

Drought is one of the consequences of a reduction of rainfall over a long period of time. Often a number of meteorological elements as high temperatures, strong winds and low relative humidity occurs in conjunction with the drought. These facts make drought very strongly expressed. The present paper aims to analyze the intensity and the seasonal differences of meteorological drought in Northeastern Bulgaria and to characterize the drought impact on the main crops cultivated in the study area. The tendencies of the seasonal and the annual air temperatures and precipitation are investigated. Drought periods are revealed on the base of precipitation anomalies and the drought indices as Standartized Precipitation Index (SPI) and De Martonne Index. The driest years for the period 1961 – 2011 have been established. The production of the main crops in the study area is analyzed on the background of climate change. The information from climate models is used in order to describe future climate and to make the recommendations for crop cultivation in relation to climate impact.