Restricting movement for the population and the impact of preventative measures due to the COVID-19 pandemic have spurred research interests in analyzing the healthy lifestyle of the student population. The aim of the study was to examine gender differences between students in physical activity, and the perceptions of physical fitness and well-being during lock-down due to COVID-19. The sample consisted of male (n=268; 25.9%; age 22.56±2.12) and female students (n=768; 74.1%; age 22.12±1.73) at the University of Sarajevo (UNSA). The questionnaire included questions and scales constructed to measure: physical activity, physical fitness, and the acute effects on well-being. χ² independence test were used to determine gender differences (p<0.05). Prior to the declaration of the COVID-19, there was a significant difference in the level of regular physical activity between male and female students at UNSA (p<.01). The data indicated that at that time 65% of male students were regularly physically active, while 45% of female students had regular physical activity. During the lock-down measures at UNSA: 46% of male and 40% of female students reported being regularly physically active and no significant differences were found in relation to gender (p>.05); 65% of male and 58% of female students reported a decline in physical fitness and significant gender differences were found (p<.05). After exercising male students reported better concentration and mood, more energy and motivation, and less nervousness in the range of 62–79%, while female students reported better concentration and mood, more energy and motivation, and less nervousness in the range of 62-81%. No significant differences were found in the physical activity acute effects on students' well-being in relation to gender (p>.05). Although gender differences in physical activity disappeared during the early phase of COVID-19 and lockdown measures, a more pronounced decrease in physical fitness was present in female students. The reported physical activity had equally positive acute effects on students' well-being.

BACKGROUND Digital video recordings are increasingly used across various medical and surgical disciplines with advances in computer hardware and software technologies. The creation of high-quality surgical video footage requires a basic understanding of key technical considerations, together with creativity and sound aesthetic judgment. Online operative videos have become a core resource within neurosurgical education. OBJECTIVE To provide a step-by-step description for making operative videos using a video from a real case as an example. METHODS We recorded an operative video of the microsurgical resection of a right lateral ventricle subependymoma performed by an anterior interhemispheric transcallosal approach. The patient consented to surgical resection of the subependymoma and to publication of this operative video. With the video, we explain the step-by-step process the authors used for developing the raw video into a publishable surgical video. RESULTS The patient depicted in our video tolerated the surgery well and made a complete recovery. The final video produced from the surgery illustrated elements that Operative Neurosurgery, Neurosurgery, and other journals require in surgical videos. CONCLUSION Although more than 1200 peer-reviewed (PubMed) neurosurgical operative videos have been published so far, there has not been a single publication that describes the step-by-step process of producing an operative video. To the best of our knowledge, this is the first published detailed description of editing of an educational operative video in neurosurgery and the first video case report of a microsurgical resection of subependymoma of the lateral ventricle in the peer-reviewed English literature.

The 87Sr/86Sr isotope ratio can, in principle, be used for provenancing of cement. However, while commercial cements consist of multiple components, no detailed investigation into their individual 87Sr/86Sr isotope ratios or their influence on the integral 87Sr/86Sr isotope ratio of the resulting cement was conducted previously. Therefore, the present study aimed at determining and comparing the conventional 87Sr/86Sr isotope ratios of a diverse set of Portland cements and their corresponding Portland clinkers, the major component of these cements. Two approaches to remove the additives from the cements, i.e. to measure the conventional 87Sr/86Sr isotopic fingerprint of the clinker only, were tested, namely, treatment with a potassium hydroxide/sucrose solution and sieving on a 11-µm sieve. Dissolution in concentrated hydrochloric acid/nitric acid and in diluted nitric acid was employed to determine the 87Sr/86Sr isotope ratios of the cements and the individual clinkers. The aim was to find the most appropriate sample preparation procedure for cement provenancing, and the selection was realised by comparing the 87Sr/86Sr isotope ratios of differently treated cements with those of the corresponding clinkers. None of the methods to separate the clinkers from the cements proved to be satisfactory. However, it was found that the 87Sr/86Sr isotope ratios of clinker and cement generally corresponded, meaning that the latter can be used as a proxy for the clinker 87Sr/86Sr isotope ratio. Finally, the concentrated hydrochloric acid/nitric acid dissolution method was found to be the most suitable sample preparation method for the cements; it is thus recommended for 87Sr/86Sr isotope analyses for cement provenancing.

Polyhydramnios is a condition related to an excessive accumulation of amniotic fluid in the third trimester of pregnancy and it can be acute and chronic depending on the duration. Published data suggest that during muscle development, in the stage of late histochemical differentiation decreased mechanical loading cause decreased expression of myosin heavy chain (MHC) type 1 leading to slow-to-fast transition. In the case of chronic polyhydramnios, histochemical muscle differentiation could be affected as a consequence of permanent decreased physical loading. Most affected would be muscles which are the most active i.e., spine extensor muscles and muscles of legs. Long-lasting decreased mechanical loading on muscle should cause decreased expression of MHC type 1 leading to slow-to-fast transition, decreased number of muscle fiber type I especially in extensor muscles of spine and legs. Additionally, because MHC type 1 is present in all skeletal muscles it could lead to various degrees of hypotrophy depending on constituting a percentage of MHC type 1 in affected muscles. These changes in the case of preexisting muscle disorders have the potential to deteriorate the muscle condition additionally. Given these facts, idiopathic chronic polyhydramnios is a rare opportunity to study the influence of reduced physical loading on muscle development in the human fetus. Also, it could be a medical entity to examine the influence of micro- and hypogravity conditions on the development of the fetal muscular system during the last trimester of gestation.

Aim: The aim of this study is to assess the knowledge of sexually transmitted infections (STIs), sexual habits, and behavior among students of medical and nonmedical students in Serbia. Methodology: The cross-sectional study of 1,273 university students of four undergraduate institutions in Serbia, two of medical and two of nonmedical orientation. A standardized questionnaire, prepared in line with the questionnaire of the European health research—the second wave (European Health Interview Survey—EHIS wave 2), according to defined internationally accepted indicators, was used as a survey instrument. Results: Statistically significant difference (p < 0.001) between medical and nonmedical student groups was determined for the following parameters: naming four of five STIs (29.1 vs. 13.4%), knowledge about vaccines against some STIs (26.0 vs. 17.0%), relationship between HPV infection and cervical malignancy (48.2 vs. 16.7%) engaged in the sexual relations (87.9 vs. 76.4%), never used a condom (15.2 vs. 10.4%), underwent gynecological or urological examination (66.7 vs. 44.1%), and tested to one of STIs (10.5 vs. 4.9%). Conclusion: Both student groups have limited knowledge on possible consequences that risky sexual behavior has for reproductive health. Promotion of knowledge about STIs, awareness of all complications, and consequences of these infections certainly affect the reduction of risky behavior.

This paper investigates the impact of foreign direct investment on economic growth, on a sample of three groups of countries, classified according to the criterion of economic development. The research problem that seeks to be solved is defined by the question: Do foreign direct investment affect the economic growth of targeted countries and in what way? The objectives of the research are to explain the mechanism of functioning of foreign direct investment and the implications for macroeconomic growth parameters, ceteris paribus. The results of the research show the existence of correlation and determination of the dependent variable with the variations of the independent variable. In this way, the main hypothesis of the paper was confirmed, that foreign direct investment has a stimulating effect on economic growth and the effect of investment is a priori determined by the defined economic policy and the appropriate institutional and legislative framework of the countries, ceteris paribus. The methods used in this paper are regression analysis, i.e. simple linear regression, and analysis and synthesis of previous research and theoretical findings, in order to draw conclusions by induction. The analysis of the data confirms that foreign direct investments have an impact on the economic growth of each group of countries individually, but that in certain groups this connection is present. Thus, the results of the research showed the existence of a relation between FDI and economic growth, i.e. they emphasized FDI as a significant predictor of economic growth in the targeted groups of countries ceteris paribus. The paper represents the author's contribution to economic theory and practice, and to the general public, but also to decision-makers in developing countries. Further research should be directed towards whether it is possible to influence the increase of GDP by "copying" a certain country in terms of attracting foreigners.

Artificial neural networks (ANNs) providing sophisticated, power-efficient classification are finding their way into thin-film electronics. Thin-film technologies require robust, layout-efficient devices with facile manufacturability. Here, we show how the multimodal transistor’s (MMT’s) transfer characteristic, with linear dependence in saturation, replicates the rectified linear unit (ReLU) activation function of convolutional ANNs (CNNs). Using MATLAB, we evaluate CNN performance using systematically distorted ReLU functions, then substitute measured and simulated MMT transfer characteristics as proxies for ReLU. High classification accuracy is maintained, despite large variations in geometrical and electrical parameters, as CNNs use the same activation functions for training and classification.

Attainment of reading ability is one of the most important goals of early elementary education. The goal of the present study was to compare groups of good readers and poor readers on several cognitive and linguistic skills and to determine the influence of these variables in differentiating these two groups of readers. An additional goal was to determine whether there are differences in proportion of boys and girls in groups of good and poor readers. The sample for this study comprised 60 third-grade children divided in two categories, 30 children in the category of good readers and 30 children in the category of poor readers. The results of this study revealed the largest differences between good readers and poor readers were on the phoneme deletion task and processing speed task. Another finding is that more boys than girls were in the group of good readers and more girls than boys in the group of poor readers. It is very important to know which underlying skills best differentiate good and poor readers at certain age. This in turn will lead to creating more effective reading interventions.  

This paper describes comparative analysis of the biomechanical performances conducted on the external fixation devices whose frames are made out of two different material (stainless steel and composite material). Biomechanical properties were determined with experimental and FEM (finite element method) models which are used to study the movement of the fracture crack, establish stiffness of the design solutions and monitor generated stresses on the zones of interest. Geometric modeling of two fixation devices configurations B50 and C50 is used as a basis for structural analysis under the impact of axial load. Structural analysis results are confirmed with an experimental setup. Analyzed deflection values in the load and fracture zones are used to define the exact values of the stiffness for the construction design and fracture, respectively. The carbon frame device configuration has 28% lower construction stiffness than the one with the steel frame (for B50 configuration), i.e., 9% (for C50 configuration). In addition, fracture stiffness values for the composite frame application are approximately 23% lower (B50 configuration), i.e., 13% lower (C50 configuration), compared to steel frame. The carbon frame device has about 33% lower stresses at the critical zones compared to the steel frame at the control zone MM+ and, similarly, 35% lower stresses at the control zone MM-. With an exhausting analysis of the biomechanical properties of the fixation devices, it can be concluded that steel frame fixation device is superior, meaning it has better biomechanical characteristics compared to carbon frame fixation device, regarding obtained data for stresses and stiffnesses of the frame construction and fracture. Considering stresses at the critical zones of the fixation device construction, the carbon frame device has better biomechanical performances compared to steel frame devices.

Background and objective Tobacco tax evasion undermines the goal of tobacco taxes as a tobacco control measure to make tobacco products less affordable, increases the health risks for those who smoke and decreases the government revenue. This paper analyses the tobacco tax evasion in six Western Balkan (WB) countries: Albania, Bosnia and Herzegovina, Kosovo, Montenegro, North Macedonia and Serbia. The aim of this research is to estimate the size of the illicit market and identify the main determinants of tax evasion activities in the Southeastern European region. Data and methods Data from 2019 Survey on Tobacco Consumption in Southeastern Europe (STC-SEE) are used. STC-SEE provides uniquely comparable nationally representative data on smoking behaviour for adult (18–85 years old) population for each country. Tax evasion is defined on the basis of available information on tax stamps, health warnings, price and the place of purchase, in accordance with the previous research on tax evasion. In order to estimate the determinants of illicit purchases we use binary choice model of tax evasion. Results The study finds that 20.4% of all current smokers in WB countries evade taxes on tobacco products, with evasion being much more frequent for hand-rolled (HR) tobacco (86.7%) than for the manufactured cigarettes (MC) (8.6%). While HR is predominantly illicit in all six countries, MC evasion varies significantly, with evasion being significantly higher in Montenegro and Bosnia and Herzegovina. Results further suggest that tax evasion is higher in the statistical regions where institutional capacities to tackle illicit trade are lower, in municipalities bordering countries with high MC evasion, as well as among smokers with low income, women and elderly. We also provide evidence that higher tobacco taxes and prices do not increase illicit consumption. Conclusion The findings from the research suggest that in order to decrease tax evasion, governments should put additional effort to strengthen institutional capacities to tackle illicit tobacco markets. Furthermore, improving regional coordination in development and implementation of tobacco control policies, including the prevention of illicit market, is essential in lowering evasion in all WB countries. Finally, WB countries should regulate and enforce excise tax stamp requirements on the HR tobacco market to a much higher degree.

Biometric security is a major emerging concern in the field of data security. In recent years, research initiatives in the field of biometrics have grown at an exponential rate. The multimodal biometric technique with enhanced accuracy and recognition rate for smart cities is still a challenging issue. This paper proposes an enhanced multimodal biometric technique for a smart city that is based on score-level fusion. Specifically, the proposed approach provides a solution to the existing challenges by providing a multimodal fusion technique with an optimized fuzzy genetic algorithm providing enhanced performance. Experiments with different biometric environments reveal significant improvements over existing strategies. The result analysis shows that the proposed approach provides better performance in terms of the false acceptance rate, false rejection rate, equal error rate, precision, recall, and accuracy. The proposed scheme provides a higher accuracy rate of 99.88% and a lower equal error rate of 0.18%. The vital part of this approach is the inclusion of a fuzzy strategy with soft computing techniques known as an optimized fuzzy genetic algorithm.