FROM THE RESEARCH LABORATORIES
Eye Colour inheritance in humans
Abstract. Around 8000 years ago, in Europe appeared the first people with blue eyes. For a long time, scientists thought that the gene, responsible for the eye colour, had a dominant allele for brown eyes and recessive one for light eyes. With the development of molecular biology and genetics, however, it was discovered that the eye colour inheritance pattern is not that simple. Nowadays, scientists know that eye colour is a polygenic trait – many genes are responsible for it, which explains the enormous eye colour variation in humans.
This project examines eye colour inheritance in people. It focuses on the most important genes, responsible for eye colour – HERC2 and OCA2. The mentioned genes and their manifestation were investigated within a family by construction of a genealogical pedigree and using molecular-biological methods. The results from the experiment led to confirmation of the theoretical knowledge.
The aim of this study is to present the basic principles that underlie eye colour genetics and to explore the essential methods used by scientists daily to research complex biological topics as eye colour heredity.
Keywords: eye colour; genetics; polygenic trait; HERC2; OCA2
Viktor Gilin
National High School of Mathematics and Science (Bulgaria)
The Successful Turnover of Photosystem II Core Complexes Using Laser Flash Illumination
Abstract. Kinetics of back reaction in the S states starting with S2 →S1, was studied. This involves electron transfer from QA- back to Mn cluster. The electron transfer process start when a photon of light is absorbed by P680, which becomes excited to high energy level P680*. It acts as a primary electron donor, hence donates electron to the primary acceptor molecule Pheophytin (Pheo). Pheo then transfers electron to plastoquinone QA which becomes QA- after accepting electrons. This is how primary photosynthesis happens. To verify if the electron is returned to the donor (cyclic electron transfer) or noncyclic electron transfer, the decay kinetics was examined assuming a very rapid back reaction. Only back reaction following S2 to S1 state transition was measured. For decay of the multiline (ML) intensity in flash illuminated photosystem II (PSII) core samples, a first order reaction was assumed. The time course of decay of the S2 ML state is assumed to follow the kinetics. Results shows that the amount of energy needed for the back-reaction is very high, Ea=75 KJ/mol. This is energy needed for the electron to back react from S2 to S1 state. This high activation energy means back reaction will need high input of energy. PSII proceeds forward (noncyclic electron transfer).
Keywords: kinetics; back reaction; photosystem II; electron transfer; illumination; Kok cycle.
Bernard Baituti
Botswana International University of Science and Technology (Botswana)
Using Molecular Models to Name and Illustrate Structures of Monocyclic Compounds
Abstract. This study examined the ability of 103 undergraduate chemistry students to understand how to illustrate and name monocyclic organic compounds using molecular models in a case study that employed the action research approach. The theory that underpinned the study was constructivism. The model proved to be a powerful tool that allowed participants to build cognition and develop the necessary symbolisation and representational skills to interpret IUPAC rules for the nomenclature and structures of monocyclic organic compounds through engaging activities. They also demonstrated higher order thinking and reflective skills.
Keywords: constructivism; monocyclic compounds; molecular model; symbolisation; visualisation
Claudia Quayson, Ruby Hanson
University of Educatio – Winneba (Ghana)
EDUCATION: THEORY AND PRACTICE
Van de Graaff Generator for the Physics Classroom
Abstract. Van de Graaff generator is a simple but very useful, electrostatic generator which is able to accumulate electric charge on a hollow metal sphere. It’s only made of moving belt, rollers, motor, and copper brushes. The goal is to show that the experiment could be performed by talented elementary student with help from his teacher and meant for the physics classroom in any high school around the world.
Keywords: Van de Graaff generator; electrostatics; corona discharge; capacitance; Faraday effect; Triboelectric effect
Gorazd Blazeski, 1)Vera Zoroska
1) Hristo UzunovPrimary School – Ohrid (North Macedonia)
NEW APPROACHES
Economic Geography: from Description to Forecasting and Practical Alternatives
Abstract. The main purpose of this article is to re-think description and forecasting, as key stages of economic geography research, especially during the Fourth Technological Revolution. A critical analysis of the literature is used in order to refute methodological notions about the use of description, as a research method. The investigation results demonstrate that the expected “flood of data” that will cover all aspects of the Earth's surface, will provide new opportunities and methods to integrate the subject and object of geography: the “nature-man-society” relationship and is one of the main reasons for the prioritization of the descriptive stage of research, in respect to the geographical forecasting.
The paper points that the automation of both scientific geography and socio-economic governance requires forecast information. The scientific support of the social and corporate management and of the strategic and other planning documents for socio-economic development of the geospatial units of any scale are direct dependent on the quality of the forecast modeling and serve as a criterion for the level of development of economic geography.
Keywords: economic geography forecasting
Boian Koulov
National Institute of Geophysics, Geodesy and Geography – BAS
Integration of Online Resources on Astrobiology in The Education on Astronomy in Upper Secondary Education
Absract. This paper examines some of the main challenges for teaching science and engineering in school and includes a scientific review and includes the development of an original online video educational resource on the modern interdisciplinary scientific field of astrobiology. The produced educational resources are intended for students from X to XII grade in the upper secondary education. The content of the resources is presented in English, thus enabling students to get acquainted with the basic terminology of the currently leading language in this scientific field. As part of this work to measure the efficiency of integrating similar online resources in the education of astronomy, an original survey was conducted among students on their overall knowledge and interests in the field of astrobiology and the preferred modes of education. For this purpose, an online questionnaire was prepared and was provided to students for completion before and after getting acquainted with the online video resource.
The analysis of the results gives insight into the advantages of adding video and other interactive materials to supplement the study of advanced and underrepresented disciplines, such as astrobiology. The presented results were used for the successful defense of a master's thesis in "Astronomy and popularization of astronomy" at the Faculty of Physics of Sofia University in 2018 and are published here for the first time.
Keywords: astrobiology; education; ICT; SEN; STEM; distance learning
LETTERS TO THE EDITOR
Dr. Marchel Kostov, Assoc. Prof. – Life and Work
Absract. In memory of assoc. prof. dr. Marchel Kostov, a distinguished scientist and lecturer at the University of Architecture, Civil Engineering and Geodesy in Sofia and a respected teacher in physics at the English language school „Geo Milev“. His research was in the field of crystallography, application of crystals in optics, electrogyration effect in centrosymmetrical crystals, optical activity and birefringence of the studied crystals, construction of modulators based on elecrogyration effect, construction of laboratory models of a device for transmitting information based on an electrogyration effect, etc. His works were published mainly in Physica status solidi and Crystal Research and Technology journals. As а lecturer and assoc. professor of physics he developed new experimental setups and d emonstrations, laboratory investigations, textbooks, and a dictionary of special scientific terms. All his time and effort were dedicated to the benefit of physics research with an emphasis on materials and device applications. He spared no time and effort for a quality education in physics аt all secondary school and university levels , lecturing in both English and Bulgarian.
Zdravka Kostova, Elena Georgieva
1) Department of Information and In-service Teacher Training
Sofia University
