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In this work we analyse yearly standardized precipitation evapotranspiration index for accumulation timescale of 6 months (SPEI‐6) for August which has been identified as a strong proxy for corn production in Serbia. By applying recently proposed method generalized weighted permutation entropy (GWPE), which provides the information about predictability of large/small fluctuations in nonstationary time series, on SPEI index calculated from high‐resolution gridded dataset for the period 1951–2022, we found that the small fluctuation sequences of consecutive 4‐year SPEI values are the most predictable (indicated by lowest entropy values). The order of large fluctuation sequences is less predictable, while the order of sequences considering all magnitudes of fluctuations are the least predictable (indicated by highest entropy values). We also analysed 4‐month SPEI‐6 sequences for May, June, July and August (during the growing season of corn) along the years under study and found that they display lower GWPE values and thus are more predictable than yearly SPEI‐6 August sequences (small fluctuations displaying lower entropy values than large fluctuations). Regarding spatial distributions, in both cases SPEI‐6 sequences show similar pattern for large fluctuations: higher predictability (lower entropy values) in northern and eastern part of Serbia and lower predictability (higher entropy values) in southern and western part. For small fluctuations spatial distribution of GWPE values indicates that yearly SPEI‐6 August series are more predictable in the western part of the country while May to August monthly SPEI‐6 sequences are more predictable in the eastern part. [ABSTRACT FROM AUTHOR]

Humans and many animals have forward-facing eyes providing different views of the environment. Precise depth estimates can be derived from the resulting binocular disparities, but determining which parts of the two retinal images correspond to one another is computationally challenging. To aid the computation, the visual system focuses the search on a small range of disparities. We asked whether the disparities encountered in the natural environment match that range. We did this by simultaneously measuring binocular eye position and three-dimensional scene geometry during natural tasks. The natural distribution of disparities is indeed matched to the smaller range of correspondence search. Furthermore, the distribution explains the perception of some ambiguous stereograms. Finally, disparity preferences of macaque cortical neurons are consistent with the natural distribution.

This paper focuses on the possible impact of the thermal soil regime on the occurrence of forest fires in the Zaječar administrative district in Eastern Serbia. The study uses data on soil temperature from the Republic Hydrometeorological Service of the Republic of Serbia and the ERA5-Land gridded reanalysis dataset for monthly temperature and volumetric soil water of the soil level 1 (0-7 cm), and soil level 2 (7-28 cm) with horizontal resolution of 0.1°C (approximately 12 km × 12 km) during the period of 2009-2021. Differences in soil temperature at depths of 2 cm, 5 cm, 10 cm, and 20 cm at the meteorological station in Zaječar for the periods 1961-1990 and 2009-2021 are observed. By analyzing the data on the registered number of forest fires for the period 2009-2021, pronounced oscillations in the dynamics of forest fires can be observed. The minimum number of forest fires (0) is registered in 2014, when the maximum of soil moisture in the soil levels 1 and 2 is observed. A high number of forest fires corresponds to high soil temperatures in 2012 and 2017. Soils drier and hotter than the average are registered in 47.0% of all months with the fire occurrences. About 50% of fires occurred in dry and hot soils during 2012 and 2017. This percentage was zero in 2014, when there were no fires. [ABSTRACT FROM AUTHOR]

We investigate multifractal properties of daily means of air temperature over the territory of Serbia, by using Multifractal detrended fluctuation analysis. Temperature anomalies in two periods 1961–1990 and 1991–2020 are calculated from the E-OBSv26.0e gridded dataset with 0.10° (~12 km) resolution, totaling 1278 daily temperature series for each period. The MFDFA parameters: position of the maximum of the spectrum α0, width of the spectrum W and asymmetry r, obtained from the total of 2556 MFDFA runs are interpolated to yield their spatial distribution across Serbia in the two periods. We found several patterns in both the spatial distribution, and changes from first to second period. All series showed multifractal properties with overall persistent long-term correlations (α0 > 0.5) and the dominance of small fluctuations (r > 0). The persistence is weaker (smaller α0 values) and multifractality is stronger (larger width W) in southern mountainous regions. In the second period the values of α0 increased indicating stronger persistence of temperature dynamics, while multifractality became stronger (larger W) in northern region and weaker (smaller W) in southern region. In both periods the contribution to multifractality was dominated by small fluctuations (r > 0) that become stronger in the second period, indicated by the increase of the values of r over most of the country's area. These changes in the values of multifractal parameters indicate the increase of complexity of temperature dynamics in the second 30 years period which could be related to climate change. [ABSTRACT FROM AUTHOR]

Recently, biofertilizers are recommended as an alternative or supplement for mineral nutritients. Active agents in biofertilizers are microorganisms that are involved with their activity in the preparation of herbal assimilative and other biotic substances for plant needs. In this study, the influence of Bioaktiv bioproduct on the lettuce yield and rhizosphere microflora of lettuce was tested. 'Bioaktiv' contains the active substance consisting of following microorganisms: Bacillus subtilis, Azobacter sp., Penicillium oxalicum and Fusarium sp. In the tested soil samples of lettuce rhizosphere, the total number of bacteria, Azotobacter sp., ammonifiers, oligonitrophyls, actinomycetes and fungi were determined. The total number of bacteria, Azotobacter sp., ammonifiers, oligonitrophyls, actinomycetes was increased while the number of fungi in the variant with biofertilizer was slightly lower than in the control variant. The application of this bioproduct affected on earlier formation of the lettuce head and overall higher yield.

The aim of this research was to determine the effect of the application of different types of nitrogen fertilizer in five different varieties of lettuce on yield. The experiment was performed in the open field, in the spring cycle of growing during 2018 and 2019. The size of the base plot was 3 m², and the trial was set up in a random block system. The trial covered the application of various forms of nitrogen fertilizers: ammonium sulphate, ammonium nitrate and urea. The applied nitrogen dose is 100 kg/ha (May 10th 2018 and May 8th 2019). Samples for the analysis of vitamin C and nitrate content, as well as yield determination, were carried out at the stage of the technological maturity of lettuce (60-62 days after seedling). The average weight of lettuce, depending on the variety, varied in the range of 211.3 g to 258.7 g. The use of ammonium nitrate resulted in the highest average weight of lettuce head (246.7 g), followed by the use of urea (238.9 g) and the lowest by the use of ammonium sulphate (221.0 g). The nutritional value of lettuce (vitamin C content) shows that depending on the applied form of nitrogen in the fertilizer, the highest content of vitamin C was determined by urea (10.86 mg/100 g), then ammonium sulphate (9.61 mg/100 g), and the lowest by ammonium nitrate (7.38 mg/100 g). The lower content of vitamin C was found in varieties of lettuce with red leaves compared to varieties with green leaves. The accumulation of nitrate in lettuce leaves directly depends on the variety and the applied fertilizer. The highest nitrate content was with ammonium nitrate (2355.6 mg/kg). The accumulation of nitrate in lettuce varieties with red leaves was higher compared to varieties with green leaves. [ABSTRACT FROM AUTHOR]

The seasonal analysis of warm days in Belgrade and Niš is presented using climate indices Warm/Dry (WD) and Warm/Wet (WW) days, which are based on the daily mean temperatures and daily precipitation. Day is conceived as warm if the daily mean temperature is greater than the 75th percentile. Day is considered as dry (wet) if the daily precipitation are below the 25th percentile (higher than the 75th percentile). Analyses are made for the period 1950-2009 for Belgrade and Niš. It is obtained that the number of WD days, as well as WW days incresed in both cities, in Belgrade more than in Niš.

Knowledge of aridity is necessary to explain the characteristics of the geographical landscape. Increasing aridity due to global warming can be a real hazard, with the threat of desertification. The main aim of this paper is to introduce special software for aridity indices calculation (AICS), and on the basis of those data to peruse aridity as a natural hazard. These indices were calculated from data obtained from 10 meteorological stations in the Vojvodina region for the period from 1949 to 2006. In order to calculate the De Martonne aridity index, IDM, and the Pinna combinative index, IP, software was created using C# programming language. Not only that this software shows the values of indices, but also it shows to which class it belongs according to the De Martonne climate classification. Graphical presentation of both calculated indices is also enabled. Further development of AICS is planned. As additional software package here was used ArcMap 10.1 for the spatial representation and visualization of the aridity indices. [Projekat Ministarstva nauke Republike Srbije, br. 176020 i br. 176013]

This study provides a comprehensive analysis of changes in mean and extreme temperature indices for Serbia using a high‐resolution daily gridded temperature data set during the period of 1951–2020. The annual and seasonal trends of the indices in the gridded fields were computed and tested for statistical significance using the nonparametric Mann–Kendall test and the Sen's slope estimator. The t‐test was applied to check the stability of means of temperature indices between two standard periods (1961–1990 and 1991–2020). A correlation analysis was used in order to investigate the connections of the large‐scale circulation patterns and the mean and extreme temperature indices. Results showed that a warming trend dominated for the last 70 years, with slightly more intense changes for the mean maximum temperatures (TXM) than for the mean minimum temperatures (TNM). An increase was recorded for indices based on the maximum temperature (TXM, hottest days, warm days, summer days) and minimum temperature (TNM, coldest nights, warm nights, tropical nights). The highest increase was observed for warm nights (7 days⋅decade−1) during the summer season. The negative change in cool days (−1.5 days⋅decade−1) and cool nights (−2 days⋅decade−1) was recorded in almost all seasons, being significant for the both annual and summer values. The correlation between the temperature indices and large‐scale circulation patterns revealed that the East Atlantic (EA) pattern had a highly positive correlation with warm temperature indices (hottest days, warm days, warm nights, summer days, and tropical nights) and a negative correlation with cold indices (coldest nights, cool days, cool nights, frost days, and ice days). The North Atlantic Oscillation, the most important teleconnection pattern during the winter months in Europe, had weaker influence on temperature indices in Serbia than the EA pattern, but stronger than the EA/Western Russia pattern. [ABSTRACT FROM AUTHOR]

The present work is an analysis of the daily minimum temperatures during the period 1949-2009 in Belgrade and Niš using the climate indice TN10p, i.e. a number of days per year with the minimum temperature less than the 10th percentile (cold nights). A positive trend of the absolute minimum temperatures is found in Belgrade and Niš. It is calculated that the TN10p, i.e. number of cold nights decreases. A greater decrease of number of cold nights is recorded in Belgrade than one in Niš. The greatest decrease is observed on the annual basis, while smaller decrease is observed in autumn.

An analysis of heat waves is done using the Heat Wave Duration Index (HWDI) for Belgrade and Niš. The length and severity of heat waves at two meteorological stations in Serbia were analyzed based on the daily maximum temperatures during the summer (June, July and August) and winter (December, January and February).

Climatic changes in the last two decades on global level are presenting the fact that the planet Earth is getting warmed up. Significant temperature increasing on global level has consequences in air temperature changing on even smaller proportion. The aim of this paper is to analyze trends in air temperature, as a very important meteorological element for successful grapevine growing. Trend analysis was done based on data collected throughout the Niš-South Morava region, which was by last viticulture regional division of Serbia in 1976, separated into six sub-regions. In each sub-region, data from no less than one meteorological station were analyzed. Zone, which was named "Niš-South Morava" by the authors, includes parts of south and south-east Serbia. According to the last viticulture regional division of Serbia, 50% of area in Serbia under vineyards are situated in this Niš-South Morava region. Trend of significance on 95% level of confidence, was obtained for mean annual air temperature in all six sub-regions. Trend of mean annual air temperature during the vegetation period is significant in five vinegrowing areas. Significant trends in the whole region are increasing, which was determined by linear regression equation. Obtained equations are used to create a new list of recommended grapevine cultivars in conditions of higher mean air temperature. .

Climatic changes on the global level have consequences in changes of meteorological and climatologic conditions in vinegrowing areas. The aim of this paper was to analyze trends of the meteorological elements and determine suitability of growing grapevine cultivar in a viticulture region. Trend analysis was done, based on the data for South-Banat sub-region, an important resource for the production of grapes and wines in Pannonia plain (Vršac: H=83m, φ=45 09 N, λ=21 19 E). Trend of significance for the 95% level of confidence for mean air temperature and sunshine duration was obtained for the May - June period. For those elements, trend was increasing as well as for the precipitation in September. Correction of cultivar list was recommended, considering the obtained trends of the meteorological elements. The grapevine cultivars that ripen earlier (table and wine cultivars) are recommended, as well as those created at the Faculty of Agriculture, Department for Viticulture. .

Virtual reality (VR) technologies have experienced rapid development in recent years, leading to low‐cost consumer smartphone VR systems (with 3DoF tracking). One issue with the smartphone VR systems, which rely on existing generic displays, is simulator sickness, which arises due to factors that induce sensory conflicts, especially related to visual–vestibular conflict. Display update latency with respect to head position is one of the most widely implicated factors for simulator sickness. However, studies of the effects of latency on simulator sickness have given inconsistent results. Moreover, these studies were done on systems with latencies much higher than current smartphone VR systems. Therefore, it is hard to generalize those results to today's VR systems. To address this, we present in this paper a study on the effect of latency on simulator sickness for latency levels around 20 ms. We present a systematic evaluation of simulator sickness in smartphone VR, testing for a difference between conditions with latencies of 18 and 28 ms, on a task of natural game playing in smartphone VR. We noted differences between individuals in their reported simulator sickness for the two latency conditions but no sample‐wide significant difference. [ABSTRACT FROM AUTHOR]

The Djerdap National Park in Serbia is vulnerable to fires. The variability of a fire in the Djerdap National Park is studied depending on the impact of climatic conditions. The influence was investigated on a yearly, monthly, and daily basis using data recorded at the meteorological station Veliko Gradiste. Data were analyzed for two periods: 1961-1990 and 1991-2017, and for the year of 2011. Special attention is devoted to the conditions for the emergence of the largest forest fire in the Djerdap National Park in September 2011. In this study, the Angstrom index, the Nesterov index, and method of deficit and surplus of precipitation are used to predict the risk of fire. There was an increased danger of fire in the forests in the period of 1991-2017 compared to the period of 1961-1990. Indices showing fire risk are increased for the months of June, July, and August. The September 2011 is characterized by an increase of average monthly air temperature by 3.7 °C and a reduction of the total monthly rainfall of 32.3 mm compared to a long-term average value which favorable influenced to the occurrence of large forest fires. [ABSTRACT FROM AUTHOR]

In order to examine the influence of cultivars and to estimate how mulching and plant covering with agrotextile affects the content of P, Ca, K, Mg and Mn in lettuce leaves this three-year experiment has been established. In the experiment, black and white plastic foil were used for mulching prior to planting, and agrotextile for plant covering after planting. The effect of each of them as well as their combination on the content of nutrients and yield of lettuce leaves was examined. There were six treatments in the experiment: control, black foil, white foil, black foil and agrotextile, white foil and agrotextile, and agrotextile. Mulching had a significant impact on yield, as well as the content of P, Ca, K, Mg and Mn in lettuce leaves in the three-year experiment. The highest yield was registered in the cultivar Nizzi in treatment with black plastic foil, compared to all cultivars and treatments. The largest P content was registered in the cultivar Sunstar (0.71%), while the smallest content was registered in the cultivar Sunny (0.59%). The Ca content ranged from 2.59% (Sunny) to 2.84% (Nizzi). The Mg content ranged from 0.46% in treatment with black foil to 0.70% in treatment with white foil. The content of Mn in lettuce leaves ranged from 60.99 mg kg-1 in the cultivar Zeralda to 81.79 mg kg-1 in the cultivar Devonia. [ABSTRACT FROM AUTHOR]

In this study, the influence of the large-scale circulation patterns on temperature in Europe and Serbia is examined. Among the large-scale circulation patterns in the Northern Hemisphere, less attention has been paid to the impact of the East Atlantic/West Russia pattern (EA/WR). The relationship between the EA/WR pattern and geopotential height at 500 hPa is investigated using reanalysis data from National Centres for Environmental Prediction – National Centre for Atmospheric Research. Temperature anomalies have been explored in relation to strong positive and negative phases of the EA/WR pattern for all months. Analyzing the correlation between the EA/WR index (EA/WRI) and geopotential height at 500 hPa, a centre with negative correlation has been found throughout the year over Russia, north of the Caspian Sea. Positive (negative) temperature anomalies prevailed over Eastern (Western) Europe for the strong negative EA/WR phase (EA/WRI < −1). The temperature anomalies associated with the strong positive phase of the EA/WR pattern (EA/WRI > 1) reflect below-average temperatures over Eastern Europe. In addition, we explored the combined effects of positive and negative phases of the North Atlantic Oscillation (NAO) or East Atlantic (EA) pattern with the EA/WR pattern on temperature variations in Europe and Serbia. We find that the effect of the EA/WR pattern on temperature changes is dependent of the EA phase but not of the NAO phase over Serbia. When the EA/WRI is negative and EA pattern or NAO are in positive phase, the positive temperature anomalies prevailed over most of Europe, including Serbia. The highest values of temperature anomalies exist over Serbia for EA/WRI < −1 and EA index > 1. It is found that this case appears more frequently in the last 20 years, contributing to the warming in Europe and Serbia. [ABSTRACT FROM AUTHOR]

The comparative estimation was carried out with seven tomato hybrids (Lycopersicon esculentum Mill.) during the period 2011 to 2013 in greenhouse at Agricultural Institute of Republic of Srpska, Banja Luka, Bosnia and Herzegovina. The aim of this study is to examine the dry matter content, lycopene in fruits and total yield of Dutch tomato hybrids in the conditions of western Bosnia and Herzegovina. The experiment was set up by a randomized block design in three repetitions. The dry matter content ranged from 5.60% to 8.14%. Hybrid and hybrid x year interaction had significant (p<0.05) influence on lycopene content and tomato yield. The factors that had a decisive influence on the content of dry matter, lycopene content in fruit and tomato yield were year, hybrid and cultivation technology. [ABSTRACT FROM AUTHOR]

Seasonal prevailing surface winds are analyzed in the territory of Northern Serbia, using observational data from 12 meteorological stations over several decades. In accordance with the general definition of prevailing wind, two special definitions of this term are used. The seasonal wind roses in 16 directions at each station are analyzed. This study shows that the prevailing winds in Northern Serbia have northwestern and southeastern directions. Circulation weather types over Serbia are presented in order to determine the connections between the synoptic circulations and prevailing surface winds. Three controlling pressure centers, i.e., the Mediterranean cyclone, Siberian high, and the Azores anticyclone, appear as the most important large-scale factors that influence the creation of the prevailing winds over Northern Serbia. Beside the synoptic cause of the prevailing winds, it is noted that the orography of the eastern Balkans has a major influence on the winds from the second quadrant. It was found that the frequencies of circulation weather types are in agreement with those of the prevailing winds over Northern Serbia. [ABSTRACT FROM AUTHOR]

The article discusses the relationship between light-field imaging and display systems which is used in advance technologies such as augmented or virtual reality (VR).

Spatial and temporal variability of annual and seasonal (summer and winter) precipitation sums and mean temperatures observed at forty-six stations in Slovenia from 1961 to 2011 were analysed. Principal component analysis (PCA) and a varimax rotation with Kaiser normalization were used to determine the dominant precipitation and temperature patterns in Slovenia. Time series data from the PCA (the principal components, PCs) were used to look for the existence of linear trends and periodicity in the precipitation and temperature data using the Mann–Kendall test and spectral analysis. The relationships between the PCs and circulation patterns, such as the North Atlantic Oscillation (NAO), the East Atlantic (EA) pattern, and the East Atlantic/West Russia (EA/WR) pattern, were also examined. The first four PCs of precipitation (temperature) contributed from 78.7% in summer to 94.5% in winter (98.4% in winter to 98.5% in summer) of the total variance, and their loadings indicated that the most (least) intensive signal was observed over mountainous northwest Slovenia. A statistically significant decrease of PC1 in annual precipitation and increase in mean annual and both seasonal temperatures was found. Significant relationships existed between annual and winter precipitation in Slovenia and the NAO, and temperature and the East Atlantic pattern from 1961 to 2011. Applying the spectral analysis, periods of 2.4 years in summer precipitation and 2.8 years in winter precipitation series, and 2.1 years in annual temperature (significant at the 5% level of significance) were found in Slovenia. [ABSTRACT FROM AUTHOR]

The exponential growth in digital technology is leading us to a future in which all things and all people are connected all the time, something we refer to as The Infinite Network (TIN), which will cause profound changes in every industry. Here, we focus on the impact it will have in healthcare. TIN will change the essence of healthcare to a data-driven continuous approach as opposed to the event-driven discrete approach used today. At a micro or individual level, smart sensing will play a key role, in the form of embedded sensors, wearable sensors, and sensing from smart medical devices. At a macro or aggregate level, healthcare will be provided by Intelligent Telehealth Networks that evolve from the telehealth networks that are available today. Traditional telemedicine has delivered remote care to patients in the area where doctors are not readily available, but has not achieved at large scale. New advanced networks will deliver care at a much larger scale. The long-term future requires intelligent hybrid networks that combine artificial intelligence with human intelligence to provide continuity of care at higher quality and lower cost than is possible today. [ABSTRACT FROM AUTHOR]

Size-segregated aerosol samples were collected using six stages High Volume Cascade Impactor. Aerosol mass and water soluble ions concentrations were determined. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to study the origin of air masses arriving to Belgrade in the investigated period. The obtained results of aerosol mass and water-soluble ion concentrations have been divided into six sub-data sets based on air mass categories. The highest average mass concentration of the fine mode (Dp ≤ 0.49 μm) was found for air masses coming to Belgrade from the southeast and northwest directions, and of the coarse mode (3.0 < Dp ≤7.2 μm) for air masses arriving from the northwest direction. The highest concentrations of SO42- were found in the fine particles transported to the investigated area by air masses from southeast direction. The analysis of contribution of marine aerosol components (Na+ and Cl-), the Correlation and Cluster Analysis indicated the influence of marine aerosol on urban aerosol of the central Balkans coming from the Western Mediterranean and northern direction. NH4+ and SO42- and K+ dominated in the fine mode for all air mass categories. PCA demonstrated the dominant impact of secondary aerosol formation processes on urban aerosols. [ABSTRACT FROM AUTHOR]