rss_2.0Acta Scientifica Naturalis FeedSciendo RSS Feed for Acta Scientifica Naturalis Scientifica Naturalis 's Cover Note: Veleka Beach - the place where the mountain touches the sea model of the “Chemistry training process” system when applying semiotic approaches<abstract> <title style='display:none'>Abstract</title> <p>The present development uses the modeling method described in the literature and proposed a new didactic, functional model of the “chemistry training” system in the application of semiotic approaches: semantic, pragmatic, and syntactic. The main objective of creating such a model is to demonstrate the specific activities of the subjects “teacher” and “pupil” when familiarizing themselves with chemical symbols and their study by students. The added new components in the model “Technology of chemistry training”, “Semiotic information” and the clarified links between them, lead to a complete change in the way the described system works. The developed didactic model makes it easy to guess the relationship between a new learning situation and a result, that is, to predict an unknown process or phenomenon. This model makes it possible to formulate a reasoned hypothesis of the study.</p> </abstract>ARTICLE2022-07-28T00:00:00.000+00:00New data on the presence of the Blotched snake ( Pallas, 1814) in the region of Shumen town (Bulgaria), with emphasis on the negative human attitude toward the species<abstract> <title style='display:none'>Abstract</title> <p>In the present study, we report on new localities in Northeastern Bulgaria, where Elaphe sauromates (Pallas, 1814) was recently detected. We registered five Blotched snakes in the region of Shumen town in the period 2018 - 2022. All of the snakes were adults, three were killed by tools impacts and two of them were road kills. To date, the Blotched snake was registered extremely rare and in rather long intervals (of several decades) in the region of Shumen. Our findings indicate that the species currently inhabits the suburban and urban territories near the villages of Ivanski, Radko Dimitrievo and Konyovets. Two of the locations are new for the 10 km grid-system used for standard monitoring of the biodiversity in Bulgaria.</p> </abstract>ARTICLE2022-07-28T00:00:00.000+00:00Morphotectonic affilation of the Lilyak Plateau<abstract> <title style='display:none'>Abstract</title> <p>The morphostructural features of the Lilyak Plateau and it’s spatial and morphotectonic relationships with the adjacent parts of the Eastern Pre-Balkan Mountains are examined in the light of modern mobilist ideas. The Lilyak Plateau landform is part of the South Moesian morphostructural zone. This morphostructure borders distinctly to the south with the northern border of the corresponding part of the Fore Hemus morphostructural zone. There are significant morphostructural and morphotectonic differences between these two regional morphostructural units.</p> </abstract>ARTICLE2022-07-28T00:00:00.000+00:00Experimental study on the impact of semiotic approaches on students’ knowledge of chemical symbolism in seventh and eighth grade<abstract> <title style='display:none'>Abstract</title> <p>Experimental work in its milestones is carried out according to the following algorithm:</p> <p>1. Development of a methodological system, including additional training content in Chemistry and Environmental Protection for the seventh and eighth grades /purposefully selected urological fragments, exercises and summary lessons/, in which the subject of study is chemical symbolism, with the application of semiotic approaches - semantic, pragmatic and syntactic.</p> <p>2. Conducting a pedagogical experiment to establish the effectiveness of the developed methodological system.</p> <p>3. Analysis of the results of the pedagogical experiment.</p> <p>The pedagogical experiment is included in the work as the main method of researching the influence of semiotic approaches on the knowledge and skills of students for the proper use of chemical symbols. By conducting a pedagogical experiment, it has been shown that the use of the three semiotic approaches in Chemistry and environmental training facilitates and improves the understanding of the complex meaning of chemical symbols by students. The analysis of the results of the written control works in the seventh and eighth grades shows the existence of significant qualitative differences in students’ knowledge of how to identify chemical objects and the degree of skills formed to reveal the information embedded in chemical symbols.</p> </abstract>ARTICLE2022-07-28T00:00:00.000+00:00Global Ecological Problems of Modern Society<abstract> <title style='display:none'>Abstract</title> <p>At the modern stage of society’s development, ecology is seen as a complex, interdisciplinary science of the relationships of organisms, society and the environment. Ecology is a science that studies the regularities of the life of organisms in their natural living environment and taking into account the changes made in this environment as a result of human activity. In recent years, the mass media has been constantly talking and writing about ecology, environmental problems related to anthropogenic activity. The person with his activity is heavily polluted and continues to negatively affect the environment at increasing rates. This reckless behavior of humans and the whole of society threatens planet Earth with imminent doom, no less than the use of nuclear weapons. Only from the positions of modern science ecology is it possible to develop issues related to the prudent use of the natural resources of the biosphere and the fight against changes brought about in nature by human activity in the age of the scientific and technical revolution. For this reason, it is necessary to seek information and a solution to the key current problems: What are the main pollutants of the atmosphere, hydrosphere and lithosphere? What is the origin of these substances? How does their impact affect life on Earth? What approaches and methods are needed to prevent environmental pollution?</p> </abstract>ARTICLE2022-07-28T00:00:00.000+00:00Involvement of young people in the citizen science of invasive alien species in Bulgaria<abstract> <title style='display:none'>Abstract</title> <p>Citizen science plays an important role in the early detection of invasive alien species (IAS). The involvement of young people in initiatives related to citizen science in Bulgaria could contribute to better monitoring of IAS because of mobility and digital skills of those people. Based on a questionnaire survey, key aspects of involvement of young people in citizen science initiatives were analysed. Two groups of respondents, including professionals (with an educational background in biology or with professional activities related to the bioresources) and non-professionals (not connected with bioresources) were asked to make judgments about their own level of knowledge about: (1) IAS issues, (2) the level of awareness of citizen science; (3) the motivation and preferable ways to participate in citizen science; and (4) the most appropriate approaches for IAS awareness raising. A total of 337 young people in the age range of 15-30 years were questioned during the period 2019-2021. The results show that there is no significant difference between the responses of the two groups of respondents to the questionnaire - professionals and non-professionals. In both groups, less than 50% of respondents are aware of issues related to IAS. Less than 40% of respondents indicated the correct definition of citizen science. The leading motivation factor to participate in citizen science initiatives is “caring for nature” followed by “to contribute to nature conservation” and “to learn more about nature”. Most of the respondents are interested in additional information related to IAS and prefer online sources for information.</p> </abstract>ARTICLE2022-07-28T00:00:00.000+00:00The Effect of Nitrogen on the Structural and Electronic Properties of Graphene Sheet using Density Functional Theory<abstract> <title style='display:none'>Abstract</title> <p>The present research focuses on a theoretical study of structural and electronic properties of pure graphene sheet and then adding different number of N<sub>2</sub> atoms. The calculations are carried out using the density functional theory (DFT) with hybrid functional B3LYP/6-31G level to investigate the proposed structures. Gauss View 5.0.8 program is used to design the structures of pure and doped graphene sheets. These structures are relaxed by employing the PM6 semi-empirical method with the hybrid functional B3LYPDFT at Gaussian 09 package. The results of the structural properties of the studied graphene sheets showed that good relaxation of the structures, the constant bonds values in the pure graphene sheets in the same ranges of the carbon rings structures. We calculate the total energy, High Occupied Molecular Orbital (HOMO) and Low Unoccupied Molecular Orbital (LUMO) energies and forbidden energy gap. The result of the total energy of that doping graphene sheets is result of the binding energy of each structure and indicates that these structures have relaxation, and the effect of adding N<sub>2</sub> atoms in pure graphene sheet on the total energy of the molecule is effective. All doping graphene sheets have small forbidden energy gap, but it vibrates depending on the length and number of each sheet and the position of N<sub>2</sub> atoms in the sheets.</p> </abstract>ARTICLE2022-07-28T00:00:00.000+00:00Editorial Note: Lakes on the Northern Black Sea coast of Bulgaria medicinal plants in Bulgaria: list of species, usable parts, fields of application, toxicity and contraindications<abstract> <title style='display:none'>Abstract</title> <p>The aim of this survey is to present an up-to-date list of medicinal plants on the territory of the Republic of Bulgaria and to systematize the information on: usable parts, the number of medicinal plants used in various fields of medicine, in cosmetics, the degree of toxicity and availability of information on contraindications for all wild medicinal plants that are found in the Republic of Bulgaria. As a result, we identified a total of 845 species of wild medicinal plants. Most of them are described in a special annex to the Medicinal Plants Act of the Republic of Bulgaria. In the literature on the use of medicinal plants in Bulgaria we found information about another 115 species of wild medicinal plants. In the present survey we did review of the usable parts of medicinal plants. We made a comparative analysis of the use of medicinal plants in the official, popular and veterinary medicine. The method of application of medicinal plants in medicine is discussed: externally and internally. Attention is paid to the use of medicinal plants in aromatherapy, dentistry and cosmetics. Considered are the poisonous plants among the medicinal plants and their degree of toxicity. A review of the available data on contraindications for the use of medicinal plants has been made.</p> </abstract>ARTICLE2022-06-18T00:00:00.000+00:00An ontological model to support citizen science in the field of invasive species research<abstract> <title style='display:none'>Abstract</title> <p>Advances in information technology developments have led to improved ways and means of sharing information and good practices in various areas of social development. Providing the necessary tools enables Citizen Sciences (CS) to play an important role in raising awareness and engaging various stakeholders in the prevention of invasive alien species (IAS). In Bulgaria, up until this point, it is poorly developed, and this is largely due to the lack of information to the general public regarding the categorization of species, pathways of introduction and their negative impact. The article examines the possibilities for introduction and use of an advanced ontological model in the area of invasive alien species research, which will aid the process of involving a wide range of stakeholders in various initiatives that will contribute to preventing the introduction and spread of IAS. The researched approach using the advantages of modern information and communication technologies includes acquaintance with the basic concepts in the area of IAS, the processes related to their introduction and spread, as well as taking into account the existing interrelationships, which would provide opportunities for early detection and the rapid eradication of IAS. The developed model will also be applied to measures and policies put in place to change the attitudes of the general public to the problem of IAS.</p> </abstract>ARTICLE2022-06-18T00:00:00.000+00:00Antimicrobial drug resistance against the background of the COVID-19 pandemic in Bulgaria and Europe: A profound review of the available literature sources<abstract> <title style='display:none'>Abstract</title> <p>Improper use of antibiotics is an extremely worrying trend worldwide. This leads to the development of resistance to these drugs. As a result, antibiotics stop working and bacteria continue to grow. The highest levels of resistance, both in our country and worldwide, are to second and third-generation cephalosporins, some aminoglycosides, and others. The reason is that these antibiotics have been used most irrationally over the years. The pandemic of COVID-19 and Antimicrobial drug resistance (AMR) are parallel and interrelated serious health situations, between which there is a causal link, manifested in high mortality among the human population. This review highlights relations between growth rates of antimicrobial resistance and the Covid-19 pandemic situations in Bulgaria and Europe in this fast-growing research area.</p> </abstract>ARTICLE2022-06-18T00:00:00.000+00:00Geomorphology of the Beqaa Valley, Lebanon and Anti-Lebanon Mountains<abstract> <title style='display:none'>Abstract</title> <p>Geomorphology of Lebanon presents a unique pattern of contrasting landforms. These include two notable mountain ranges, the Lebanon and Anti-Lebanon Mountains, the Beqaa Valley, the elongated coastal area and a significant amount of karst relief forms. This study focuses on the investigation of the topographic and geologic setting of Lebanon by visualizing datasets covering Lebanon and Anti-Lebanon mountains and the Beqaa Valley. Data were collected using the open source repositories of the high-resolution data (GEBCO, ETOPO1, DEM embedded in R). Three 3D models of the relief of the country are presented based on the ‘grdview’ package of GMT with azimuth rotations of the view point at 205°/30° and 165°/30°. The geologic map is based on the compiled datasets of the USGS. The R based modelling allowed division of the raster grid into several geomorphological zones according to the slope steepness and aspect orientation. The extreme elevations of the study area range from -2007 m and 2973 m. The key contribution of this work is the topographic and geologic data synthesis for 2D and 3D modelling of Lebanon. Another aspect concerns technical integration of GMT and R scripting approaches with QGIS mapping into the cartographic framework for visualizing of the Lebanese topography as a multi-tool approach. For the future similar studies on Lebanon this paper can serve as a guide for completing a project on the multi-source 2D and 3D data mapping as a conceptual foundation for research on Lebanese environment.</p> </abstract>ARTICLE2022-06-18T00:00:00.000+00:00Late spring frost effect on the reproductive traits of late nectarine cultivar-rootstock combinations ( var. )<abstract> <title style='display:none'>Abstract</title> <p>The study was conducted during the period 2017 – 2018 at the Agricultural Experimental Station – Khan Krum, Shumen region. The experimental orchard was established in the spring of 2011. The following nectarine cultivars were studied: Fantasia, Golden Grand, Morsiani 51, Cassiopeia and Fairlane grafted on a seedling rootstock (Elberta) and clonal GF 677, as well as the frost – resistant dessert-type cultivar Redhaven. In the period 2017 – 2018, negative temperatures were reported, at the end of March and at the beginning of April (-3.6°C and -5.0 °C respectively)which coincided with the full blooming phenological phase; as a result of which the blossoms froze (76 – 100%). A relatively low percentage of frozen blossoms was observed in cultivars grafted on rootstock GF 677. In 2017, the blossom damage was relatively low and yields were obtained, unlike in 2018. Negative spring temperatures had a negative impact on productivity if blossom damage percentage exceeded 80%.</p> </abstract>ARTICLE2022-06-18T00:00:00.000+00:00Short peptide analogs of LfcinB synthesized by Solid Phase Peptide Synthesis as an alternative to global microbial resistance<abstract> <title style='display:none'>Abstract</title> <p>Antibiotics are the main therapy in the treatment of infections caused by pathogenic bacteria. Their frequent and prolonged use leads to the development and spread of resistant microorganisms. According to the WHO, there is a worrying increase in global resistance to conventional antimicrobial therapy. This in turn poses a serious risk to public health and requires the search for an alternative to traditional pathogen therapy. Antimicrobial peptides (AMPs) are of great interest in this regard. They are produced naturally in all living organisms and are the first line of defense against fungi, viruses and bacteria. An example ofAMP with proven antimicrobial action are lactoferricins. They are cationic amphipathic peptides and have been found in both humans (LfcinH) and other mammals (cattle (LfcinB), mice (LfcinM) and goats (LfcinC). The most powerful antibacterial effect among them shows LfcinB. Using SPPS methods, short peptide molecules were obtained, analogs of LfcinB, which show a stronger antibacterial effect compared to the native peptide. In recent years, lactoferricins have been the subject of a number of scientific studies and represent a potential alternative for the development of new therapies to combat antimicrobial drug resistance.</p> </abstract>ARTICLE2022-06-18T00:00:00.000+00:00Characterization of Cr(III) interaction with kaolinite – Effect of the presence of Cr(VI)<abstract> <title style='display:none'>Abstract</title> <p>In the present study, experiments were performed to characterize the effectiveness of kaolinite in Cr(III) removal from water in the absence and in the presence of Cr(VI). The results of batch experiments, show that the efficiency of Cr(III) removal by kaolinite increases with the increase of pH and temperature in both cases. The effect of the presence of Cr(VI) on the adsorption of Cr(III) by kaolinite depends on the solution pH and on the concentrations of the two ions. Whatever the system, the removal kinetic of Cr(III) is well described by the pseudo-second order model. Spectroscopic analyses reveal that Cr(III) interaction with kaolinite is mainly electrostatic.</p> </abstract>ARTICLE2021-11-23T00:00:00.000+00:00Ethnomycological research in the field of wild mushrooms and medicinal plants<abstract> <title style='display:none'>Abstract</title> <p>During the recent years, there is an increased interest in the problems of wild mushrooms and medicinal plants in all over the world. An intensive research is currently performed in order to further clarify the peculiarities of numerous edible, toxic and cultivated wild mushrooms and medicinal plants. Both traditional and contemporary knowledge of the population is assessed by means of a variety of ethnomycological and ethnobotanical methods. The manners of usage by the population of wild edible mushroom and medicinal plants are intensively studied in many countries, too. In the present review article, the results from some recent investigations by Bulgarian and foreign authors devoted to the knowledge and use of some popular wild mushrooms and medicinal plants are summarized. The necessity for the intensification of the collaborative ethnomycological and ethnobotanical research in Europe is outlined.</p> </abstract>ARTICLE2021-11-23T00:00:00.000+00:00Phytochemical screening and hemolytique activity of some leaves extracts of L.<abstract> <title style='display:none'>Abstract</title> <p>Medicinal plants have several therapeutic properties; they have been used for a long time to treat different diseases. Lantana camara L. has been widely used by man for healing these diseases. In this study, four leaves extracts of L. camara were subjected to preliminary phytochemical screening to determine the presence and/or the absence of phytochemical constituents; In addition, they were tested for hemolytic activity on human erythrocytes. This activity is performed using the UV-Vis spectrophotometer method at 520 nm and at five different concentrations (125 µg/ml, 250 µg/ml, 500 µg/ml, 750 µg/ml, and 1000 µg/ml). The phytochemical screening showed the presence of various phytochemical groups such as phenolic compounds, saponins, sterols, tannins, flavonoids, reducing compounds and the absence of alkaloids in the four extracts. These same extracts showed average hemolytic activity sequentially: chloroformic extract, petroleum ether extract, aqueous extract and then methanolic extract. This activity is dependent on the concentration of the extract.</p> </abstract>ARTICLE2021-11-23T00:00:00.000+00:00Allergenic potential of L. species in urban environment<abstract> <title style='display:none'>Abstract</title> <p>The species of the genus Platanus L. are widely used in urban green infrastructure in Bulgaria and abroad, but are proven to be a serious source of allergen pollen emissions. The number of people, affected by pollinosis, is increasing every year and this affects the world economy and health of the population in a high level. The pollen of the plane tree is light, very small and spreads anemophilically. This is one of the genera that produce the largest amount of pollen per inflorescence. This makes Platanus a tree of a high allergy potential that has the tendence to get higher in time, because of its increasing use in urban green spaces. The aim of this study is to collect data for allergy potential of the three species of plane tree in some of the European countries, where the allergy is a significant problem, and to compare the sensitization of patients to its pollen in Bulgaria.</p> </abstract>ARTICLE2021-11-23T00:00:00.000+00:00Distribution of edible, toxic and medicinal wild mushrooms in Europe and Bulgaria<abstract> <title style='display:none'>Abstract</title> <p>The scientific interest in wild mushrooms continuously increases worldwide. In the present review article, the results from some recent investigations by Bulgarian and foreign authors devoted to the current distribution of some edible, toxic and medicinal wild mushroom species in Bulgaria and some European countries are summarized. Some newly-recognized mushrooms are indicated. The examinations of wild mushroom safety under the conditions of environmental contamination deserve special attention, too. The scientists from European countries and Bulgaria have essential contributions to the field of the mushroom identification and distribution.</p> </abstract>ARTICLE2021-11-23T00:00:00.000+00:00en-us-1