Belgrade Region Research Articles

Pollen tube growth and fruit set in quince (Cydonia oblonga Mill.)

Aim of study: To determine the self-compatibility level of eight quince cultivars.Area of study: The region of Belgrade (Central Serbia).Material and methods: Pollen tube growth in vivo and fruit set in two pollination variants (self- and open-pollination) were studied in eight quince cultivars. The quantitative parameters of pollen tube growth (average number of pollen tubes in the upper and middle third of the style, base of the style and in the ovary; the dynamics of pollen tube growth through these parts of the pistil) was determined using the fluorescence microscopy.Main results: The parameters of pollen tube growth and fruit set were primarily dependent on the genotype and variants of pollination. All studied parameters were significantly higher in the open-pollination variant compared with the self-pollination in all cultivars. In the self-pollination variant, ʻLeskovackaʼ and ʻVranjskaʼ had the highest number of pollen tubes that penetrated the ovary (2.10 and 0.54 in average, respectively), as well as the largest percentage of pistils with the penetration of pollen tubes in the nucellus of ovules six days after pollination (40.09% and 14.74%). Also, they had the highest percentage of initial fruit set (17.01% and 28.52%) and final fruit set (9.32% and 9.86%). Based on this, ʻLeskovackaʼ and ʻVranjskaʼ can be classified as self-compatible cultivars, while the others are self-incompatible.Research highlights: The majority of quince cultivars were self-incompatible. When establishing new orchards with these cultivars, care should be taken about the choice of pollenisers in order to achieve high yields.

Evaluation of some German plum cultivars in the region of Belgrade (Serbia)

Evaluation of some German plum cultivars in the region of Belgrade (Serbia)

Seroprevalence of hepatitis E in pigs and wild boars in the region of the city Belgrade

Hepatitis E is considered an emerging human viral disease with many evidences of zoonotic nature of disease, and swine are the main reservoir of HEV. The aim of this study was to determine HEV seroprevalence in commercial pig farms, backyard pigs, slaughtered pigs and wild boars in the region of the city Belgrade. A total of 405 sera samples: 150 samples from 3 commercial pig farms, 70 samples from backyard pigs, 119 samples from slaughtered pigs and 66 samples from wild boars of the region of the city Belgrade, Serbia were analysed by commercial ELISA test. The overall HEV seroprevalence in 3 commercial pig farms was 55.33% (83/150). All tested farms (farm A, B and C) were positive on the presence of anti-HEV antibodies, respectively 58% (29/50), 54% (27/50) and 54% (27/50). From 70 tested backyard pigs, 75.71% (53/70) were tested seropositive. In total, 26 backyard pig holidngs were confirmed as positive to anti-HEV antibodies (81.25%). At slaughterhouse, 25% (8/32) weaned piglets and 20.69% (18/87) fattening pigs were tested positive on anti-HEV antibodies. Overall HEV seroprevalence in tested wild boar population was 52.25% (36/66). Detected very high seroprevalence of anti-HEV antibodies indicated an active circulation of HEV, being enzootic in the swine population, and wild boars, as well, in the region of the city Belgrade.

Lipid profile and health benefit of commonly consumed fresh water and sea water fish species in the population of Serbia

Background/Aim. Dietary intake of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) is important in prevention and treatment of different diseases. In general population, the average intake of n-3 LC-PUFA is often significantly lower than recommended levels. Fish lipids are rich sources of these fatty acids, of which the most important are eicosapentaenoic (20:5 n-3, EPA) and docosahexaenoic (22:6 n-3, DHA) fatty acids. This study was designed to determine and compare fat, fatty acids and lipid quality indices in 10 commercial fish species available on the Serbian market, as well as relation between their price and nutritional value. Methods. Freshwater fish originated from the Danube River in the Belgrade Region, while seawater fish were mostly from the Adriatic Sea. A gas chromatography method was used to define fatty acids in 40 fish samples after lipid extraction. Cost-minimization analysis was conducted to assess the economic utility. Results. Seawater fish had a significantly higher value of flash lipid quality compared to the freshwater fish (p < 0.05). Value of hypercholesterolaemic fatty acids (OFA) for the freshwater group was 18.70 (17.40?21.30) while the seawater group had a similar range of values 18.90 (17.55?22.75). Hypocholesterolaemic fatty acids (DFA) also showed similar ranges for both groups: 68.80 (66?70.20) for freshwater and 68.40 (64.85?73.05) for seawater group. The ratio of DHA/EPA ranged from 1.8 for sardine samples and up to 10 for tuna samples, indicating that the amount of DHA in natural samples exceeds the amount of EPA in many cases. The values of atherogenic (AI) and thrombogenic index (TI) were lower than 1 for all analysed samples. Conclusion. Sardine and mackerel had the highest content of n-3 LC-PUFA and presented the least expensive sources of EPA and DHA. The low values of AI and TI obtained from studied fish indicate its benefits from a health point of view.

Models for the Calculation of Diffuse Radiation on Solar Collectors

For the design and exploitation of solar energy systems, information of both direct and diffuse component of solar radiation is necessary. However, the measurement data that are available are usually restricted to total horizontal irradiance. Therefore, many models have been developed to determine the diffuse component of the irradiance on solar collectors. This paper discusses the most well-known isotropic and anisotropic models for the calculation of the diffuse component of the solar irradiance. A modification of the isotropic clear day model for determining the diffuse component of solar radiation on a horizontal surface has been presented. The presented model has the same form as a simple clear day model, with the parameters determined using the least squares method and measurement data on horizontal irradiance in the region of Belgrade, Serbia. The applicability of isotropic clear day models was examined. The paper also discusses the applicability of the models for determining the diffuse irradiance on tilted collectors in real weather conditions during the year. The basic expressions are given and the characteristics of individual models are highlighted. Based on the measurement data on horizontal irradiance, the possibilities of applying different models for the calculation of the diffuse component of irradiance on solar collectors located in the region of Belgrade were examined.

Principal characteristics of patients acutely poisoned by ethanol in the region of Belgrade (Serbia)

Background/Aim. Acute intoxication by ethanol constitutes a significant part of the acute pathology caused by toxic chemicals, which require medical care in specialized health care institutions. The aim of the study was to determine some principal characteristics of the patients treated after acute ethanol poisoning, such as: participation in the total number of patients treated after acute poisoning by all chemical agents, age, sex, severity of poisoning and capacities for ambulatory or hospital treatment. Methods. A five-year retrospective case study was conducted on 20,891 acute poisoned patients, of which 10,731 were treated after acute ethanol poisoning during the period 2011?2015. All the subjects satisfied the diagnostic criteria of poisoning according to the World Health Organization International Classification of Diseases-10 and standardized Poison Severity Score scale. Results. Monitored parameters were analyzed in 10,731 patients acutely poisoned by ethanol, and their average number during one study year was 2146.2 ? 437.95. The average number of treated patients due to poisoning by ethanol (51.47 ? 2.86%) was statistically significantly higher than that of other causes of acute poisoning (p < 0.001). The majority of poisoned patients were men, aged 19 to 65 years, with mild to moderate symptoms of acute ethanol intoxication. The highest number of patients poisoned by ethanol had Poison Severity Score 1 (70.25 ? 5.04%, p < 0.001). Very few acute poisoned with ethanol required hospital treatment (1.05%). Anticipated number of patients acutely poisoned by ethanol had high percentage of increase for the period 2016?2020 (slightly more than 20%), which is worrying, primarily due to their high absolute number. Conclusion. Acute alcohol poisoning represents a significant part of the pathology in the total number of patients treated due to acute poisoning with various chemical substances. The results of this analysis showed that certain populations are particularly vulnerable to abuse of alcohol to the level requiring health care (male population, age 19?65 years). Only a small number of patients (1% of all patients treated for acute alcohol poisoning) required clinical treatment. The obtained data provided the basis for a more targeted preventive action in certain population groups, as well as the adequate planning of professional medical staff engagement, material, spatial and other capacities. These data, also, provided the basis for additional detailed social, economic, health and other researches in this area as well as a more detailed registration of this type of poisoning and establishing a monitoring system and database.

Flowering phenology of apricot cultivars in the Belgrade region

The phenology of flowering was studied in 50 apricot cultivars in the Belgrade region over a period of eight years (2009-2016). Within the flowering phenophase, three sub-phases were registered: the beginning of flowering, full flowering and the end of flowering. In addition, the duration and abundance of flowering were examined. The average date of the beginning of flowering for all cultivars was March 22, of full flowering - March 25, and of the end of flowering - April 1. The average duration of flowering was 9.7 days, with a range among cultivars between 7.5 days ('Gergana') and 12 days ('Ninfa ' and 'Radka'). The lowest average score (3.0) for flowering intensity was obtained in 'Hungarian Best' cultivar, and the highest score (4.6) in 'Harcot' and 'Leskora' cultivars. In years with higher temperatures during the flowering, a smaller range in flowering time among cultivars was recorded, as well as shorter duration of flowering. Based on the beginning of flowering, the tested cultivars were classified into three groups: early-flowering (14 cultivars), medium-flowering (21 cultivars) and late-flowering (15 cultivars). Meteorological factors (air temperature) had a greater influence on the course and duration of the flowering phenophase than the genetic traits of the cultivars.

Regionalizacija kao mera razvoja ruralnih područja Republike Srbije

Given the existence of marked differences between rural and urban areas, as well as between Belgrade and other regions of the Republic of Serbia, the subject of the paper should point out these differences, while the aim of the research will be to arrive at important factors that create these differences, as well as opportunities to overcome them through balanced regional development. For this, appropriate parametric and non‐parametric techniques were used in the study to compare groups. The Kruskal‐Wаllis test showed that employment in the primary sector dominates all regions over Belgrade, while the Mann‐Whitney test leads to the conclusion that the primary sector dominates in rural areas over urban. The one‐factor ANOVA of different groups found that agricultural income was higher in all regions than Belgrade, while the T‐test of independent samples and the Mann‐Whitney test showed that these incomes together with natural consumption were higher in rural areas than in urban. Since the Kruskal‐Wаllis test showed that the Belgrade region is the least poor and the Mann‐Whitney test showed a greater percentage of rural poverty than urban, even regional development, as well as the development of the agribusiness sector and diversification of activities in rural areas, are essential to bring about their development.

Evaluation of some diploid plum cultivars in the region of Belgrade

Evaluation of some diploid plum cultivars in the region of Belgrade

EVALUATION OF LATE PLUM CULTIVARS IN THE REGION OF BELGRADE (SERBIA)

Phenological traits, yield, and fruit characteristics of 14 plum cultivars of late maturation period were stud-ied in the region of Belgrade in the five-year period (2013–2017). The control cultivar for comparison was ‘Stanley’. The average time of flowering was in the first half of April, and of fruit maturation in the second half of August and the beginning of September. Yield per tree was lowest in the cultivar ‘Pozna Plava’ (10.2 kg) and highest in the cultivar ‘Topking’ (23.6 kg). Compared to the control, significantly lower yield was achieved in three cultivars: ‘Pozna Plava’, ‘Vengerka Pozdnyaya’, and ‘Narach’. Fruit weight ranged from 26.1 g in the cultivar ‘Elena’ to 57.0 g in the cultivar ‘Empress’. Compared to the control, it was sig-nificantly higher in three cultivars (‘Empress’, ‘Vengerka Pozdnyaya’, and ‘Tophit’). All studied cultivars had high soluble solids content, ranging from 17.1% to 21.6%. The best rated cultivar for fruit appearance was ‘Empress’, while cultivars ‘Nada’ and ‘Pozna Plava’ were best scored for taste.

Evaluation of coding ill-defined and unknown causes of death in the Republic of Serbia

One of the most frequently used indicators for the quality of mortality statistics is the use of R-codes as the cause of death (COD) in death certificates. The aim of this study was to analyse the coding of ill-defined and unknown causes of death in the Republic of Serbia (RS). The data for this descriptive study, covering a ten-year period (2006–2015), were obtained from the National Mortality Register. Since population and economic features differ widely between regions in RS, we compared the Belgrade region (BR) with other regions (Or). We estimated the frequency of certain types of death investigation methods regarding R00-99-coded deaths. The frequency of R-codes, by subcategories, and code-specific mortality rates were calculated by region for each year. The use of R-codes was significantly lower in BR than in Or (OR 0.85; 95% CI, 0.84-0.66; p < 0.001). The most frequent method of determining COD was external examination of the body, both in BR and Or (60.7% and 85.5%, respectively). The rate of forensic autopsies in BR was 38.1% while in Or it was only 3.6%. Clinical autopsies were performed in 1% of deaths in BR, compared to 0.5% in Or. Our results suggest that in BR the use of R-codes compared to other CODs has decreased over the past years while there has been an increasing trend in autopsy proportions; in Or the frequency of R-codes, as well as of autopsy proportions, has remained unchanged.

Element Contents in Muscle Tissue of Prussian Carp from Different Lakes in an Urban Area

The aim of this study was to determine the content of some elements (Pb, Cd, Hg, Fe, Cu, Zn, As) in muscle tissue of Prussian carp (Carassius auratus gibelio) from seven different lakes in the Belgrade region, Serbia. Concentrations of Pb, Hg and As in fish muscle tissues from all examined lakes were under the maximum residual levels prescribed by the European Union (EU) and the maximum allowed concentrations (MAC) for Serbia. In all investigated fish, levels of Cd exceeded maximum allowed concentrations (0.05 mg kg-1). Data on the finding of elements in fish speak concurrently about the safety of fish as food and are good indicators of environmental pollution.

Chilling and heat requirements for flowering in apricot cultivars

Chilling requirements for breaking dormancy and heat requirements for flowering were studied in 10 apricot cultivars in the region of Belgrade during a 2‑year period. Chilling requirements were determined using the Utah chill unit (CU) model. To determine the date of dormancy breaking, 1-year-old shoots were collected weekly from December to February and kept under controlled conditions. Heat requirements were calculated as growing degree hours (GDH) accumulated from the breaking of dormancy to the beginning of flowering using a base temperature of 4°C. The cultivars studied showed a range of chilling requirements, from 834 CU in ‘Ninfa’ and ‘Goldrich’ to 1442 CU in ‘Re Umberto’. The heat requirements for flowering ranged between 2624 GDH in ‘Magyar kajszi’ and 3469 GDH in ‘Tomcot’. The latest flowering cultivar (‘Re Umberto’) finished dormancy 42 days after the earliest flowering cultivar (‘Ninfa’). The results indicate that flowering time of apricot in the studied region is influenced more by chilling requirements than by heat requirements. Identification and selection of cultivars with higher chilling requirements and later flowering is important for apricot production, especially in regions with the frequent occurrence of late spring frosts.

New radiolarian data from the Jurassic ophiolitic mélange of Avala Mountain (Serbia, Belgrade Region)

An ophiolitic melange of Avala Mountain located south of Belgrade was studied to obtain age data from blocks of radiolarian cherts and to enable better understanding of age and nature of this melange. The studied area is located south of Avala Mt. and its geotectonic position is rather obscure. The obtained data allow us to determine radiolarians from five samples; one is of Late Anisian to Early Ladinian, and four of them are of Middle Jurassic (Late Bathonian–Early Callovian) age. The finding of Triassic as well as Jurassic age radiolarians in one and the same melange suggests that this melange formed during obduction of the Western Vardar ophiolites.

Phenological characteristics, yield and fruit quality of medium-late ripening plum cultivars in the region of Belgrade

Phenological characteristics, yield and fruit quality of 14 medium-late ripening plum cultivars, were studied in the region of Belgrade during the five-year period (2013-2017). The control cultivar for comparison was ?Cacanska rodna?. Flowering of tested cultivars occurred in the first half of April, and fruit maturation was in the first half of August. The average yield per tree was the lowest in the ?Nevena? cultivar (1.6 kg), and the highest in the ?Mildora? cultivar (22.5 kg). Compared to the control cultivar, significantly lower yield was achieved in seven cultivars. The lowest vigor was determined in the standard cultivar (?Cacanska rodna?), and the highest in the ?Milka? cultivar. The average fruit weight ranged from 19.5 g in the ?Nevena? cultivar to 50.5 g in the ?Valor? cultivar. Compared to the control, fruit weight was statistically significantly higher in five cultivars. In all studied cultivars, the high soluble solids content (over 17%) was found, while in cultivars ?Mildora? and ?Valor? it was significantly higher than in the control. On the basis of the obtained results, as regards cultivation in the region of Belgrade, it is possible to recommend the following cultivars: ?Valor? and ?Cacanska najbolja? as predominantly table cultivars (for fresh consumption), ?Jojo? and ?Vengerka krupna slatka? as cultivars of combined characteristics and ?Mildora? as a cultivar for processing.

Prevalence and risk factor analysis for feline haemoplasmas in cats from Northern Serbia, with molecular subtyping of feline immunodeficiency virus

ObjectivesThe objectives of this study were to estimate the prevalence of feline haemoplasma infections in Northern Serbia, identify potential risk factors and perform molecular subtyping of feline immunodeficiency virus (FIV).MethodsPCR analysis for feline haemoplasmas was performed on surplus EDTA blood samples from 373 cats from the Belgrade region, Serbia. An ELISA was used to determine the prevalence of feline leukaemia virus (FeLV) and FIV; PCR was performed on a subpopulation of these cats. FIV subtyping was performed using PCR.ResultsWithin this population, 64/373 cats (17.2%) were infected with one or more haemoplasma species. Mycoplasma haemofelis was detected in 20/373 cats (5.4%), ‘Candidatus Mycoplasma haemominutum’ in 47/373 cats (12.6%) and ‘Candidatus Mycoplasma turicensis’ in 23/373 cats (6.2%). Coinfections were observed in 21/373 cats (5.6%). Based on ELISA serological retroviral testing, 4/310 cats (1.3%) were infected with FeLV, whereas 78/331 (23.6%) were infected with FIV. Multivariable analysis identified significant associations between haemoplasma infection and anaemia (anaemic/non-anaemic, odds ratio [OR] 2.7, 95% confidence interval [CI] 1.04–7.1; P = 0.041]), male gender (male/female, OR 4.5, 95% CI 2.22–9.03; P <0.0005), outdoor access (yes/no, OR 5.2, 95% CI 2.28–11.92; P <0.0005), non-pedigree breed (non-pedigree/pedigree, OR 5.5, 95% CI 1.24–24.84; P = 0.025) and FIV seropositive status (positive/negative, OR 2.4, 95% CI 1.21–4.83; P = 0.012). PCR analysis of the FIV ELISA-positive samples revealed clade D as being the most prevalent.Conclusions and relevanceAll three known species of feline haemoplasma were detected, confirming their presence in Serbia; ‘Candidatus Mycoplasma haemominutum’ was the most prevalent. We found a high prevalence of FIV-infected cats and FIV clade D was most prevalent.

Pokrivenost proizvodnje zrnastih proizvoda skladišnim kapacitetima u Srbiji

The subject of this paper is the annual production of important grain crops in Serbia (corn, wheat and soybean), as well as the available grain storage capacities (silos, floor storages and baskets). The aim of this research is to determine the utilization rate of grain crop storage capacities in Serbia as a whole and in four Serbian regions separately according to the average and extreme (maximum) production of the crops examined. On the basis of the analysis conducted, it was noted that the storage capacity in Šumadija, Western Serbia, the Belgrade region and Vojvodina was underutilized, whereas the production in Southern and Eastern Serbia exceeded the available storage capacities. Moreover, considering the data referring to floor storages and silos, it can be concluded that in Southern and Eastern Serbia, the average production exceeded the total available storage capacities by 7.3 %, whereas the maximum annual production was 13.7 % higher than the storage capacities. .

Simulation Based Productivity Forecast of 1 MW PV Power Plant in the Weather Conditions Typical for Belgrade Region

Simulation Based Productivity Forecast of 1 MW PV Power Plant in the Weather Conditions Typical for Belgrade Region

Summer weather characteristics and periodicity observed over the period 1888–2013 in the region of Belgrade, Serbia

With the goal of finding summer climate patterns in the region of Belgrade (Serbia) over the period 1888–2013, different techniques of multivariate statistical analysis were used in order to analyze the simultaneous changes of a number of climatologic parameters. An increasing trend of the mean daily minimum temperature was detected. In the recent decades (1960–2013), this increase was much more pronounced. The number of days with the daily minimum temperature greater or equal to 20 °C also increased significantly. Precipitation had no statistically significant trend. Spectral analysis showed a repetitive nature of the climatologic parameters which had periods that roughly can be classified into three groups, with the durations of the following: (1) 6 to 7 years, (2) 10 to 18 years, and (3) 21, 31, and 41 years. The temperature variables mainly had one period of repetitiveness of 5 to 7 years. Among other variables, the correlations of regional fluctuations of the temperature and precipitation and atmospheric circulation indices were analyzed. The North Atlantic oscillation index had the same periodicity as that of the precipitation, and it was not correlated to the temperature variables. Atlantic multidecadal oscillation index correlated well to the summer mean daily minimum and summer mean temperatures. The underlying structure of the data was analyzed by principal component analysis, which detected the following four easily interpreted dimensions: More sunshine-Higher temperature, Precipitation, Extreme heats, and Changeable summer.

Urban-rural fog differences in Belgrade area, Serbia

Urban/rural fog appearance during the last 27 years in the Belgrade region is analysed using hourly meteorological records from two meteorological stations: an urban station at Belgrade-Vracar (BV) and a rural station at Belgrade-Airport (BA). The effects of urban development on fog formation are discussed through analysis of fog frequency trends and comparison with a number of meteorological parameters. The mean annual and the mean annual minimum temperatures were greater at the urban BV station than at the rural BA station. The mean monthly relative humidity and the mean monthly water vapour pressure were greater at the rural than urban station. During the period of research (1988–2014), BA experiences 425 more days with fog than BV, which means that BV experiences fog for 62.68% of foggy days at BA. Trends in the number of days with fog were statistically non-significant. We analysed the fog occurrence during different types of weather. Fog in urban BV occurred more frequently during cyclonal circulation (in 52.75% of cases). In rural BA, the trend was the opposite and fog appeared more frequently during anticyclonic circulation (in 53.58% of cases). Fog at BV occurred most frequently in stable anticyclonic weather with light wind, when a temperature inversion existed (21.86% of cases). Most frequently, fog at BA occurred in the morning and only lasted a short time, followed by clearer skies during the anticyclonic warm and dry weather (22.55% of cases).