The changes in the prices of base and precious metals on the global metal market have a significant impact on credit risk factors. The link between these factors has been neglected over the years by ...traditional credit risk models. The inclusion of correlation coefficients within the set credit risk model will show the impact of these changes on other variables of credit risk over the years under review and the impact of these changes on the probability of default and the recovery rate. Changes in base metals prices on the London Metal Exchange (LME) for lead and zinc and the London Bullion Metal Association (LBMA) for gold and silver as precious metals were used in the proposed credit risk model for the period of ten years. The research was done by using the multivariate regression analysis model and based on the statistical model evaluation,the significant impact of all observed independent variables on the dependent variable of the proposed model was proved. The construction of the proposed model with proven predictability gives a scientific significance to the research that includes variables of models from different markets, which have a significant impact on the variables from the financial market.
Remodelling of collagen fibers has been described during every phase of cancer genesis and progression. Changes in morphology and organization of collagen fibers contribute to the formation of ...microenvironment that favors cancer progression and development of metastasis. However, there are only few data about remodelling of collagen fibers in healthy looking mucosa distant from the cancer. Using SHG imaging, electron microscopy and specialized softwares (CT-FIRE, CurveAlign and FiberFit), we objectively visualized and quantified changes in morphology and organization of collagen fibers and investigated possible causes of collagen remodelling (change in syntheses, degradation and collagen cross-linking) in the colon mucosa 10 cm and 20 cm away from the cancer in comparison with healthy mucosa. We showed that in the lamina propria this far from the colon cancer, there were changes in collagen architecture (width, straightness, alignment of collagen fibers and collagen molecules inside fibers), increased representation of myofibroblasts and increase expression of collagen-remodelling enzymes (LOX and MMP2). Thus, the changes in organization of collagen fibers, which were already described in the cancer microenvironment, also exist in the mucosa far from the cancer, but smaller in magnitude.
New technologies have a significant role in modern financial markets. The application of new technologies, application and software solutions has enabled financial institutions and individual and ...institutional investors to use mathematical-statistical and econometric models, which are based on analysis and evaluation of investment portfolios, financial risk assessment and extrapolation, as well as predictability related to cyclical economic trends, which are directly reflected in the investment portfolio. Due to the impact of the financial crisis, and especially due to global negative economic trends caused by the COVID-19 pandemic, alternative forms of financial assets that are directly created by the application of new technologies are becoming increasingly important in the international financial market. These alternative forms of financial assets are presented as cryptocurrencies. Bitcoin is the first cryptocurrency in the global financial market, and Ethereum is the second cryptocurrency in terms of market turnover. In this regard, arises the question: "Do these two leading cryptocurrencies have a significant impact on the modern financial market, as well as on the decision of individual and institutional investors regarding a different structure of the investment portfolio?" Restructuring the investment portfolio by including cryptocurrencies, aims to achieve portfolio diversification in order to better manage market and financial risks. This paper will analyze the impact of cryptocurrencies, their volatility, turnover volume and the possibility of using them as alternative financial assets of an optimal investment portfolio.
The application of groundwater vulnerability methods has great importance for the sanitary protection zones delineation of karstic sources. Source vulnerability assessment of karst groundwater has ...mainly relied on the European approach (European Cooperation in Science and Technology—COST action 620), which includes analysis of the K factor, which refers to water flow through the saturated zone of the karst system. In the paper, two approaches to groundwater vulnerability assessment have been applied, COP + K and TDM (Time-Dependent Model) methods, to produce the most suitable source vulnerability map that can be transformed into sanitary protection zones maps. Both methods were tested on the case example of Blederija karst spring in Eastern Serbia. This spring represents a classical karst spring with allogenic and autogenic recharge. Dual aquifer recharge points out the necessity for the inclusion of the vulnerability assessment method created especially for the assessment of karst groundwater. Obtained vulnerability maps show similar results, particularly in the spring and the ponor areas, and these zones are most important for future protection. The COP + K method brings out three vulnerability classes that can be directly transformed into three sanitary protection zones. Contrary to the previous one, the TDM method uses water travel time as a vulnerability degree. The results show that the final map can be easily used to define sanitary zones considering different national legislation.
The aim of this research is related to the influence of swimming on the development of motor abilities of students of younger school age, as well as defining the skills that are most developed under ...the influence of swimming. Differences in anthropometric characteristics and motor abilities between the two groups of students were analysed. One group consisted of students who, in addition to physical and health education classes, practice swimming (students/swimmers), and the second group consisted of students who do not engage in any additional organised physical activities (students). The sample of the respondents included 18 students, members of the Belgrade swimming club "Mornar" and 17 students of "Branko Radičević" primary school from Pančevo, all aged 10 years ± 6 months. In addition to basic anthropometry, an assessment of motor abilities was also carried out, with the help of the tests of strength, speed, endurance, flexibility, agility, balance, and coordination. By analysing the differences using the t-test for independent samples, the group of students/swimmers showed generally better results, and a statistically significant difference between the groups at the level of significance (p<.005) was found in five motor tests: Standing long jump, Stick twist, Lying-sitting for 30 sec., Seated forward bend, and Bent arm hang. The obtained research results indicate that swimming, as a basic physical activity, has a positive effect on the development of the motor abilities of the students of younger school age, especially on strength and flexibility. The authors' recommendations go in the direction of paying more attention to swimming as a physical activity that has a positive impact on the development of students' motor abilities.
The implementation of sanitary protection zones is one of the most widely used approaches for preventive groundwater protection. Current regulations are usually based on the determination of the ...horizontal groundwater travel time component, while the vertical component is commonly neglected. Karst aquifers are especially sensitive to contamination through the unsaturated zone, and consequently numerous methods for determining intrinsic vulnerability have been developed. Many of these methods take into account the effects in the unsaturated zone, but mostly by indirect means. Vulnerability assessment methods do not fully reflect the component of groundwater residence time, making groundwater delineation zoning more difficult, with possible ambiguous and subjective results. Therefore, a method that incorporates the two equally important components (horizontal and vertical) is needed to facilitate groundwater protection zoning. The time-dependent model represents a redesigned vulnerability assessment method, created for karst aquifers, to incorporate the travel time component. This model incudes horizontal and vertical groundwater flow components and also considers a surface component toward ponor zones. The baseline for groundwater travel time through the unsaturated zone was adopted from the Time–input method. The estimation of the horizontal travel time component was based on the conceptual duality of flow in karst aquifers, which has fast and slow components. For the allogenic part of the karst aquifer catchment area (subcatchments of the ponor zone) travel time components were estimated according to different influencing factors e.g. slope, soil type, vegetation, and rainfall intensity. This methodology was tested on the case example of the Crnica karst source located at the western part of the Kučaj anticline in Eastern Serbia. The methodology was shown to be more accurate and appropriate for the delineation of the groundwater protection zones than existing approaches.
Europe has a long mining history, with some mining sites dating back to prehistoric times. Mining activities have boosted industrial development in many European countries; however, on the other ...hand, they left behind large degraded areas and polluted sites. This mining heritage, from small-scale mines to large industrial mining complexes, adversely affects natural resources and the environment. Exploration and mining of mineral ores have been quite extensive in Serbia. Most exploited were as follows: coal, copper, Pb–Zn ores, accompanying gold and silver and antimony. Groundwater resources are frequently impacted by mining operations, both during mining activities and after mine closure. For proper protection and management of groundwater resources, it is necessary to identify and characterize pollution sources within groundwater bodies. Abandoned mining sites, along with associated facilities for the preparation and processing of ores, waste rock disposal sites and tailings, constitute potential hazards and can have a negative effect on groundwater quality. This paper describes a methodology developed for regional-scale screening of the groundwater pollution risk from abandoned mining sites. As a first step, intrinsic groundwater vulnerability was assessed on the basis of readily available data. As potential polluters, 59 abandoned mining sites were included in the analysis. The hazard identification process comprised physical characterization of mining sites and hydrochemical assessment of mine water originating from those sites. A simple indexing method was developed for hazard and risk quantification. To assess the spatial distribution of the groundwater pollution risk, all data were incorporated and analyzed in a GIS environment. As a result of initial screening, several abandoned, mostly metallic mines were found to have higher-risk ratings for groundwater contamination. The methodology based on examples from Serbia can also be used in other regions for developing management strategies and directing of remediation activities.
Background: The primary goal of this study was to investigate the relationship between body composition and motor coordination performance, and the secondary goal was to determine sex differences in ...body composition and motor coordination of preschool children. Methods: Forty-eight children (23 boys and 25 girls) underwent assessments for body composition and motor coordination using the Köperkoordinationstest für Kinder (KTK). Results: Linear regression analysis revealed significant associations between body composition and motor coordination in boys (p < 0.05) but not in girls. In boys, Body height (p = 0.01), Total muscle mass (p = 0.03), Total fat (p = 0.03), and Total water (p = 0.02) show statistically significant influence on single-leg jumps. Similar results were obtained for lateral jumps where there was a statistically significant influence of Body height (p = 0.01), Total muscle mass (p = 0.03), and Total water (p = 0.02). Interestingly, predictive variables showed no statistically significant influence on KTK overall score in boys (p = 0.42) nor in girls (p = 0.90). Conclusions: The predictive system of morphological variables demonstrated significance only among boys in this age group and sample. Girls outperformed boys due to early maturation, resulting in better average KTK scores.
Many groundwater sources face a reduction in the exploitation capacity due to well aging. The well changes its performance over time, whether in operation or out of work. The well aging is influenced ...by many factors. Consequently, economic, business and social problems arise. Well regeneration has shown the best effects in practice to address these issues. In the area of Kladovski Ključ on the banks of the Danube, a drainage system of wells is used to defend against high water levels. During the inspection of the wells, the products that affect the aging of the well were determined, and the regeneration of the wells was conducted using the chemical-hydraulic method. The paper presents the procedures of well regeneration and the obtained positive effects of the applied method seen through the achieved results.
Purpose Investigation of the influence of different conditioning contraction protocols on the eccentric variables in terms depth of descent of body centre of mass at countermovement jump as well as ...capacity of muscle force, power, and velocity at countermovement jump, and depth jump, i.e., velocity at time of rebound both mentioned jumps. Methods In a sample of 29-students (age: 19.6 ± 0.8), 1 repetition maximum was determined by estimating 10 repetition maximum, to be stratified in a six-week workout. Static group practiced hold back squat at 120° for 12 seconds, dynamic group practiced back squat at 120° (x8) for 12 seconds, and combined group practiced 2 back squat at 120° and 2 seconds endurance (x2) for 12 seconds. Control group had a 6 to 8 hours of activity per week. After the pre-contractions, they continuously performed shock-plyometrics (50 cm box), triple jump and 5-meter sprint. Training load was 80% of 1 repetition maximum. Results A statistically significant increase (13.3, and 9.3%) was found in spontaneous descent of body centre of mass at static and dynamic group, unlike in combined and control group (4.4, and 5.5%). In variables force, power, and velocity eccentric phases of countermovement jumps, significant performance ranges of experimental groups from 5.9 to 13.3% were found, unlike in depth jump variables for which there was no significance. Concentric variable in terms velocity time of rebound countermovement jump exhibits significance for dynamic and combined groups in values (3.4, and 4.3%), i.e., same variable of depth jump for static, dynamic, and combined groups in values (2.0, 2.9, 4.1%, respectively; p<0.05). Conclusion The most indicated increases in variable, velocity at time of rebound at both jumps, were observed after the dynamic loads, referring to sublimated eccentric and concentric manifestations of muscular effects.
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