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The paper examines secondary school students' perceptions of the connection between school climate and school safety among secondary school students. A positive school climate and a safe school environment are significant factors in the academic success and proper psychosocial development of students. Therefore, it is important to examine the structure and interrelationship of indicators of school climate and school safety in order to contribute to a clearer and more grounded creation of school policies. The research was conducted through a questionnaire. The School Climate Questionnaire measures three factors: teacher and school support, student engagement and interactions, and rigid discipline. The School Safety Questionnaire measures four factors: violent behavior, unsafe school environment, victimization, and violation of norms. A sample of 719 students from nine secondary schools in the territory of the Republic of Serbia completed self-report questionnaires that measured school climate and school safety. The research confirmed the connection between school climate and school safety. Specifically, teacher and school support builds significant low negative associations with all dimensions of school safety. Student engagement and interactions build a medium negative association with violation of norms, while with the other three dimensions of school safety it builds low negative associations. Rigid discipline should be seen as a separate phenomenon in relation to the concept of school climate, and it builds low positive associations with the factors violation of norms and unsafe school environment. Promoting positive interactions among all participants in the educational process through various activities to encourage and develop desirable forms of behavior (teaching about the correct ways to resolve conflicts, support in the educational process, etc.) by the school and teachers would significantly contribute to the construction of a safe school environment.

Serbian military topographic and cartographic activity has existed for almost 150 years. During that time, a relatively small country like Serbia faced difficult temptations but successfully produced topographic maps. During this period, Serbia was affected by numerous wars and other trials. First, there was a war for liberation with the Turkish Empire, then came the Balkan Wars, the First and Second World Wars and the transformation of Yugoslavia from a kingdom into a socialist state, as well as the final disintegration of Yugoslavia. During all that time, the Serbian army managed to create maps that were a necessary tool used by many civilian institutions. Serbian military topography developed solutions related to geodetic surveying, and cartography provided and developed many maps of different scales with appropriate cartographic keys. Although it often faced difficult situations, the Military Geographical Institute - MGI managed to recover, train new personnel, and continue with topographic surveying, map making, aerial photogrammetry, application of satellite images and implementation of digital technology. In this paper, we provide primary data on the development of military cartographic and topographic activity through a presentation of results and activities from establishing the Military Geographical Institute to the present day. The topographic activity, in addition to topography, includes trigonometric and levelling surveying.

The aim of this study was to develop and validate a sensitive RP-HPLC method for the determination of usnic acid, as a potential marker substance of the herbal product for oromucosal use being a complex mixture of plant extracts and an essential oil, including the extract of Usnea barbata. Analysis of usnic acid in the tested formulation was performed through an extraction with methanol, prior to injection onto the HPLC column (Zorbax Eclipse XDB-C18 600 Bar (4.6 mm×100 mm, 1.8 μm)). The employed gradient procedure of the solvents (phosphoric acid (pH 2.5) and acetonitrile), at flow rate of 0.1 mL min-1 allowed for the efficient and reproducible separation of usnic acid from the other compounds present in the investigated complex mixture. The established suitability, linearity, precision, accuracy and selectivity/specificity of this assay implied its applicability for the reliable examination in the stability study of the investigated multi-ingredient herbal preparation.

The paper looks at different approaches to the defining and operationalization of the concept of school safety, with the aim of identifying the fundamental conceptual and operational dilemmas and problems, as well as highlighting the importance of the concept and of its adequate definition, in view of the implications it has for understanding the phenomenon, for research, and for the creation of school policy. The fundamental question which is the focus of the paper is examined in terms of the conceptual definition of school safety, the problem of operationalization and the problem of research. As part of this question, we have sought to define the concept of school safety, pointing to the broader and narrower definitions of the concept itself, and its relationship with other, related concepts and the conceptual dilemmas arising from this. The problem of the operationalization of this concept is represented through three approaches in the identification of school safety dimensions: the risk management approach; the approach linked to school violence; and the approach of creating a learning-focused school environment. In the last section - the research question - the difficulties identified by researchers while conducting research into school safety are presented. The conclusion states that only a clearly defined and well-founded conceptual framework, the defining of research objectives, that is, the selection of the range of behaviors and experiences relevant to the topic, and the evaluation of the characteristics of the cultural environment and the respondents' age, can lead to the adequate selection and determination of indicators of school safety, as well as the removal of difficulties in its operationalization and measurement.

Background/Aim. Cyclamen hederifolium (C. hederifolium) Ait. belongs to the family Primulaceae, which includes 23 species of cyclamen, naturally distributed in the Central and Southern Europe, Western Asia and some parts of North Africa. This plant is considered highly poisonous and not suitable for human use. However, tuber extracts have been used in traditional medicine and homeopathy. The aim of this study was to investigate C. hederifolium growing naturally in Serbia for its metal content and biological activities (anti-oxidant, antibacterial, antifungal and cytotoxic activity). Methods. Content of metals was determined by atomic absorption spectrophotometric method. We used several different assays for assessment of antioxidant activity of both aqueous and ethanol extracts of C. hederifolium: 2.2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,20-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assay, ferric-reducing antioxidant power (FRAP) assay, total reducing power assay (TRP) and cupric reducing antioxidant capacity (CUPRAC) assay. The disk diffusion assay was used to investigate sensitivity of laboratory bacterial and fungal control strains against investigated extracts. Aqueous and ethanol extracts of C. hederifolium were examined on 4 different tumoral cell lines by in vitro MTT bioassay. Results. The presence of Mn, Ca, Mg, Fe, Zn, K, Cu was confirmed in aqueous and ethanol extract, as well as in whole tubers and soil, while Cr, Ni, Pb and Cd were not detected. Both aqueous and ethanol extract of C. hederifolium tubers showed antioxidant activity, that positively correlated to content of phenols and flavonoids in it. Aqueous extract was slightly superior in these terms than ethanol one. None of the tested extracts showed antimicrobial activity. Both investigated extracts showed cytotoxicity against four cancer cell lines 4T1, HCT116, CT26, LLC1, in the concentration range 15,625–2,000 μg/mL. Ethanol extract showed stronger cytotoxicity than aqueous ex-tract. Conclusion. Seven metals were identified in the C. hederifolium tubers, extracts and soil. Both extracts exhibited antioxidant and cytotoxic activity.

The aim of the research was to determine the extent to which citizens perceive the connection between climate change and infectious diseases, i.e. whether they recognize them as a risk factor that contributes to the emergence and distribution of infectious diseases, and to what extent they see epidemics as a serious (security) threat. At the same time, the respondents' familiarity with key concepts was examined. The research was conducted on a convenient sample of 140 respondents, with a Questionnaire constructed for that purpose. Descriptive statistics were used in data processing. By analyzing the obtained results, it was determined that the largest percentage of respondents are familiar with the meaning of the term "infectious diseases", then "climate change", as well as the term "epidemic of greater epidemiological significance". Furthermore, a high level of perception of the connection between climate change and infectious diseases, i.e. recognizing the effects they may have on the occurrence and spread of infectious diseases. According to the obtained results, it was determined that the respondents see the infectious epidemic as a threat to the political stability of the state, health, economic and corporate security, as well as the importance of public education for prevention and response in case of epidemic, but also the lack of adequate capacities and resources for response.

Supercritical CO2 extraction was applied on fenugreek (Trigonella foenum-graecum L., Fabaceae) seeds with the aim to define optimal process conditions to obtain the maximal extract yields content of steroidal sapogenins. Central composite rotatable design (CCRD) combined with response surface methodology (RSM) was applied to determine optimal process conditions defined by the influence and interaction of pressure, temperature and time of extraction through consumption of SC CO2. Optimization experiments revealed that the pressure of 24.73 MPa, the temperature of 38.°C and the consumption of SC CO2 of 19.24 g/gDM were the best process conditions enabling the maximal yield of extract and gain of the highest content of sapogenins. The optimal values of pressure and temperature defined SC CO2 density of 885.47 kg/m3, which provided the maximal yield of the extract with the highest content of steroidal sapogenins. The achieved yield of extract at these conditions was 0.073g/gDM, with 0.774 mg/gDM diosgenin, 0.477 mg/gDM protodioscin, 0.713 mg/gDM sarsapogenin and 0.205 mg/gDM oleanolic and ursolic acid with a significant quantity of 2.475 mg/gDM in the obtained extract. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III45017]