Coincidence of flood waves in the Sava and Drina Rivers

U radu je prikazana teorijska osnova za definiranje koincidencije velikih voda u zoni značajnog međusobnog utjecaja glavne rijeke i pritoke. Prikazane su matematičke osnove i procedure za definiranje linija istih vjerojatnosti pojave, kao i linija vjerojatnosti prekoračenja dvije slučajne varijable. Za slučaj složenog riječnog sustava, ograničenog s dva ulazna profila (na glavnoj rijeci i pritoci) i jednog izlaznog (na glavnoj rijeci), bez značajnog utjecaja dotoka s međusliva, definirane su relevantne konstelacije (kombinacije) maksimalnih godišnjih protoka i njegovih odgovarajućih (sinkronih) vrijednosti protoka na ostalim ulazno/izlaznim profilima. Precizirani su pravci praktičnog korištenja definiranih zavisnosti koincidencija velikih voda, a to su: a) definiranje mjerodavnih protoka za ekonomsko-optimalni proračun linija nivoa vodnog lica u zoni međusobnog utjecaja glavne rijeke i pritoke; b) definiranje mjerodavnih velikih voda različitih vjerojatnosti pojave na sektoru glavne rijeke, nizvodno od ušća pritoke, ako su poznati samo protoci na dva ulazna profila (na glavnoj rijeci i pritoci); c) ocjena statističke značajnosti povijesnih i prognoziranih poplava. Rezultati primjene navedene procedure proračuna koincidencije velikih voda prikazani su za sektor rijeke Save, od vodomjerne postaje Županja do vodomjerne postaje Sremska Mitrovica, s uključivanjem donjeg toka rijeke Drine, od vodomjerne postaje Radalj do ušća u Savu. Rad je, numerički i grafički, ilustriran rezultatima proračuna pod a), b) i c), za navedeni sektor rijeka Save i Drine.The paper presents a theoretical basis for defining the coincidence of flood waves in the zone of significant interaction between the mainstem and its tributary. It shows the mathematical bases and procedures for defining the lines of same probabilities of occurrence and the lines of probabilities of exceedance for two random variables. In the case of a complex river system, limited by two inlet profiles (on the mainstem and its tributary) and one outlet profile (on the mainstem), without a significant influence of inflow from the intercatchment, the relevant constellations (combinations) of maximum annual discharges and their corresponding (synchronous) discharge values on other inlet/outlet profiles were determined. The following practical uses of the defined dependences of flood wave coincidences were determined: a) Definition of design discharges for economically optimal calculation of water table lines in the zone of interaction between the mainstem and its tributary; b) Definition of design floods of different probabilities of occurrence on the mainstem section downstream of the tributary mouth, if only the discharges on two inlet profiles (on the mainstem and its tributary) are known; c) Assessment of the statistical significance of historical and forecast floods. The application results of this procedure of the calculation of flood coincidences are presented for the section of the Sava River from the gauging station Županja to the gauging station Sremska Mitrovica, with the inclusion of the Lower Drina River from the gauging station Radalj to its confluence with the Sava River. The calculation results mentioned under points a), b) and c) for these Sava and Drina sections are used for numerical and graphic illustration of the paper

A comprehensive approach to determining the Drava River flood hydrographs for hydrotechnical design

Ovaj je rad posvećen određivanju teorijskih hidrograma velikih voda rijeke Drave u profilu hidrološke postaje Donji Miholjac. Primijenjena se procedura temelji na jednom novom sveobuhvatnom pristupu koji usporedno vodi računa o dva osnovna parametra hidrograma velikih voda – maksimalnoj ordinati hidrograma (vrhu) i zapremini poplavnog vala. Razrađena procedura u osnovi se oslanja na praktičnu primjenu, usporedno, metode „graničnog intenziteta otjecanja“ (GIO) za proračun teorijskih hidrograma velikih voda različitih vjerojatnosti pojave i teorije dvodimenzionalnog definiranja funkcija raspodjele (koincidencije) navedenih parametara hidrograma velikih voda. Važna pretpostavka je da se, u konkretnom slučaju, tretiraju osnovni parametri hidrograma velikih voda – ordinate maksimalnih godišnjih protoka i maksimalne zapremine hidrograma velikih voda u istoj kalendarskoj godini. Kalibracija parametara metode GIO vrši se u uvjetima izjednačavanja teorijskih vrijednosti maksimalnih godišnjih protoka i maksimalnih godišnjih zapremina istih vjerojatnosti pojave, koji se dobivaju primjenom metode GIO, odnosno standardne procedure prilagođavanja navedenih vremenskih serija teorijskim funkcijama raspodjele koje se najčešće koriste u hidrološkoj praksi. Za definiranje vjerojatnosti istovremene pojave navedenih parametara hidrograma velikih voda (vrha i maksimalne zapremine hidrograma velikih voda) korištena je procedura koincidencije dvije slučajne varijable, prikazana u literaturi (Prohaska et al., 1999.; Prohaska et al., 2016.). Definirane koincidencije vjerojatnosti prekoračenja dva promatrana parametra hidrograma velikih voda služe za odabir kombinacija koje će se koristiti za kalibraciju parametara metode GIO. Na kraju je prikazan praktični primjer definiranja teorijskih hidrograma velikih voda različitih vjerojatnosti pojave na rijeci Dravi u profilu hidrološke postaje Donji Miholjac.The paper deals with the determination of theoretical hydrographs of the Drava floods at the Donji Miholjac hydrological station profile. The applied procedure is based on a recent comprehensive approach which simultaneously considers two basic flood hydrograph parameters- maximum hydrograph ordinate (peak) and flood wave volume. The elaborated procedure primarily relies on the practical, simultaneous application of two methods – the method of "limit discharge intensity" (GIO method) for the calculation of theoretical flood hydrographs of different probabilities of occurrence and the theory of two-dimensional definition of the distribution function (coincidence) of the mentioned flood hydrograph parameters. In this specific case, an important assumption is that the basic parameters of the flood hydrograph (ordinate of maximum annual discharges and maximum volume of flood hydrograph) are from the same calendar year. The calibration of the GIO method parameters is carried out in the conditions of equalizing the theoretical values of maximum annual discharges and maximum annual volumes of the same probability of occurrence which are obtained by applying the GIO method, i.e. standard procedure of adjusting the mentioned temporal series to the theoretical functions of distribution which are the most frequently used in the hydrological practice. In order to define the probability of a simultaneous occurrence of the stated flood hydrograph parameters (peak and maximum volume of the flood hydrograph), the procedure of two random variable coincidence was used, as shown in literature (Prohaska et al., 1999; Prohaska et al., 2016). The defined coincidences of probability for exceeding two monitored flood hydrograph parameters serve to facilitate a selection of combinations to be used for the calibration of the GIO method parameters. Finally, the paper includes a practical example of defining theoretical flood hydrographs with different probabilities of occurrence in the Drava River at the Donji Miholjac hydrological station profile

Identification and classification of Serbia's historic floods

River flooding in Serbia is a natural phenomenon which largely exceeds the scope of water management and hydraulic engineering, and has considerable impact on the development of Serbian society. Today, the importance and value of areas threatened by floods are among the key considerations of sustainable development. As a result, flood protection techniques and procedures need to be continually refined and updated, following innovations in the fields of science and technology. Knowledge of high flows is key for sizing hydraulic structures and for gauging the cost-effectiveness and safety of the component structures of flood protection systems. However, sizing of hydraulic structures based on computed high flows does not ensure absolute safety; there is a residual flood risk and a risk of structural failure, if a flood exceeds computed levels. In hydrological practice, such floods are often referred to as historic/loads. The goal of this paper is to present a calculation procedure for the objective identification of historic floods, using long, multiple-year series of data on high flows of natural watercourses in Serbia. At its current stage of development, the calculation procedure is based on maximum annual discharges recorded at key monitoring stations of the Hydro-Meteorological Service of Serbia (HMS Serbia). When applied, the procedure results in the identification of specific historic maximum stages/floods (if any) at all gauge sites included in the analysis. The probabilistic theory is then applied to assess the statistical significance of each identified historic flood and to classify the historic flood, as appropriate. At the end of the paper, the results of the applied methodology are shown in tabular and graphic form for various Serbian rivers. All identified historic floods are ranked based on their probability of occurrence (i.e., return period)

Association between chronic periodontitis and serum lipid levels

Background/Aim. Periodontitis is a local inflammatory process mediating destruction of periodontal tissues triggered by bacterial insult. However, this disease is also characterized by systemic inflammatory host responses that may contrbute, in part, to the recently reported increased risk for systemic diseases, including an altered lipid metabolism. On the other hand, many people in the world are affected by hyperlipidemia, which is a known risk faktor for atherosclerosis. The aim of this study was to determine the relationship between periodontal disease and blood lipid levels. Methods. A total of 50 patients with periodontitis included in this study had no documented history of recent acute coronary events. The healthy, non-periodontal subjects (comparison group) comprised 25 subjects. All the patients were periodontology examined and completed a medical history. Dental plaque index, probing depth, gingival index bleeding on probing and clinical attechment levels were recorded. Blood samples were taken on admission for measurements of serum total cholesterol, triglycerides, hight density lipoprotein cholesterol (HDL-cholesterol), and low density lipoprotein cholesterol (LDL-cholesterol). Results. The obtained results showed that mean levels of cholesterol (6.09 ± 1.61 mmol/L), triglycerdes (2.19+1.67mmol/l) and LDL cholesterol (4.09 ± 1.40 mmol/L) in individuals with periodontitis were higer, and levels od HDL (1.43 ± 0.51 mmol/L) was lower than those of individuals without periodontitis (4.86 ± 1.37; 1.14 ± 0.71; 3.18 ± 0.64; 1.53 ± 0.32 mmol/L, respectively). Conclusion. This study confirms a significant relationship between periodontal disease, regardless its intensity, and blood lipid levels in the studied population. The results imply that periodontitis may be a risk factor and may contribute to the pathogenesis of atherosclerosis and cardiovascular diseases (CVD). However, future prospective randomized studies have to determine whether periodontal disease is a risk factor for the occurrence of CVD

Phenolic Composition, Antioxidant, Anti-Enzymatic, Antimicrobial and Prebiotic Properties of Prunus spinosa L. Fruits

Blackthorn (Prunus spinosa L.) fruit is bluish-black wild fruit traditionally used in nutrition and medicine. It is recently gaining attention as a functional food and an underutilized source of bioactive compounds for application in the food and pharmaceutical industry. This study aimed to assess the health-promoting potential of blackthorn fruits from Serbia by examining their chemical composition and in vitro biological activities. Phytochemical analysis of the blackthorn fruit extracts was performed using LC-DAD-ESI-MS. The total phenolic (TPC), total flavonoid (TFC), total anthocyanin (TAC) content, antioxidant capacity, and enzyme inhibitory activities were determined spectrophotometrically. The antimicrobial and prebiotic properties were tested using the broth microdilution method. Twenty-seven phenolics belonging to the classes of hydroxybenzoic and hydroxycinnamic acids derivatives, flavonoids, and anthocyanins were identified, with caffeoylquinic acid as the most abundant compound. Blackthorn extracts were characterized by notable TPCs, TFCs, and TACs, and free radical scavenging and reducing ability. The enzyme inhibitory effects (IC50 = 0.43–2.16 mg/mL) were observed towards α-amylase, α-glucosidase, acetylcholinesterase, and tyrosinase. Blackthorn fruit extracts in a concentration-dependent manner (0.3–5 mg/mL) stimulated the growth of several probiotic microorganisms and their mixtures, especially the yeast Saccharomyces boulardii. Obtained results support further evaluation of the functional food potential of blackthorn fruit

The significance of adiponectin as a biomarker in metabolic syndrome and/or coronary artery disease

© 2015, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All rights reserved. Background/Aim. Adiponectin exerts profound protective actions during insulin resistence or prediabetes progression towards more severe clinical entities such as metabolic syndrome and/or cardiovascular disease. Since hypoadiponectinaemia contributes to the pathophysiology of the metabolic syndrome and coronary artery disease the level of circulating adiponectin may be an early marker of cardiovascular events. The aim of this study was to determine the relationships between serum adiponectin levels and parameters of both insulin sensitivity and obesity in patients with the metabolic syndrome and/or coronary artery disease, as well as to assess predictive value of adiponectin serum levels as a biomarker of these entitetis. Methods. The study included 100 patients with metabolic syndrome and/or coronary artery disease with different degree of insulin resistance and healthy, normoglycemic individuals. The control group comprising healthy, normoglycemic individuals was used for comparison. Serum level of adiponectin, fasting glucose, fasting insulinemia Homeostasis Model Assessment of Insulin Resistance (HOMAIR) index and anthropometric parameters were determined in all the subjects. Adiponectin was measured by using the ultrasensitive ELISA method. Insulinemia was measured by the radioimmunoassay (RIA) method. The presence of glycemic disorders was assessed on the basis of oral glucose tolerance test (OGTT). Results. Adiponectin level was inversely correlated with age (ϱ = - 0.015), parameters of both obesity (R = 0.437; p < 0.001) and insulin resistance (R = 0.374; p < 0.01). Decreasing in the level of adiponectin was strongly implicated in the development of insulin resistance. Most importantly, a statistically significant rapid decrease in adiponectin was in the prediabetic stages (p < 0.01). The predictor value of adiponectin was 1,356.32 ± 402.65 рg/mL. Conclusions. The obtained resultats suggest that adiponectin may be a useful marker in identification of individuals with risk of developing metabolic syndrome and coronary artery disease, as well as a predictor of prediabetes

Historical floods along the Danube River from 1012 to the present

U radu su kronološki prikazane sve značajnije poplave koje su se događale duž Dunava od srednjeg vijeka do danas. Prikaz započinje prvom evidentiranom poplavom iz 1012. godine i završava 2013. godinom. Imajući u vidu različite izvore podataka koji su korišteni, za opis poplava u prošlosti pri izradi ovoga prikaza obuhvaćeno je povijesno razdoblje dulje od 1100 godina podijeljeno na tri karakteristična razdoblja: razdoblje 1012.-1500. (stari vijek), kada su poplave ocijenjene na temelju materijala iz povijesne arhive korištenjem originalnih rukopisa, isječaka iz novina, pisanih kronika, formalnih pisama, karata i fotografija; razdoblje 1501.- 1820., kada su poplave procijenjene hidrauličkom rekonstrukcijom tragova (oznaka) zabilježenih maksimalnih razina vode na starim zgradama, vjerskim objektima i sl. te razdoblje od 1821. do danas, kada su poplave sagledane na temelju službenih podataka opažanja i mjerenja državnih hidrometeoroloških službi u podunavskim zemljama. Iz evidentiranog niza značajnih poplava duž Dunava izdvojene su one koje su, prema vrijednostima temeljnih parametara hidrograma velikih voda, maksimalnoj ordinati hidrograma – Qmax (m3/s) i zapremini poplavnog vala W (106 m3), iznad vjerojatnosti premašivanja: P {Qmax ≥ qmax,p) ∩ (Wmax ≥ wmax,p)} = 1.0% Ove se poplave nazivaju povijesnim poplavama. U radu su prikazana odgovarajuća povratna razdoblja T(Qmax ∩ Wmax) svih registriranih povijesnih poplava duž Dunava, od izvora do brane HE Đerdap, za razmatrano višegodišnje razdoblje, od 1012. godine do danas.The paper provides a chronological overview of all significant floods that have occurred along the Danube River from the Middle Ages to the present time. The overview begins with the first recorded flood in 1012 and ends with 2013. Considering different data sources that were used, for the description of floods in the past we used a historical period longer than 1100, divided into three characteristic periods: the 1012-1500 period (Antiquity), for which floods were assessed based on materials from the historical archives, such as original manuscripts, newspaper excerpts, written chronicles, formal letters, maps and photographs; the 1501-1820 period, for which floods were assessed based on the hydraulic reconstruction of traces (marks) of recorded maximum water levels on old buildings, religious buildings, etc.; and the period from 1821 to the present, for which floods were assessed based on official data and measurements of state hydrometeorological services in the Danube countries. From the recorded series of significant floods along the Danube, we have separated those that are, according to the values of the basic parameters of flood hydrographs – maximum hydrograph ordinate – Qmax (m3/s) and flood wave volume W (106 m3), above the exceedance probability: P {Qmax ≥ qmax,p) ∩ (Wmax ≥ wmax,p)} = 1.0% These floods are called historical floods. The paper presents the relevant return periods T (Qmax ∩ Wmax) for all recorded historical floods along the Danube, from its source to the dam of the HPP Đerdap, for which the multiannual period from 1012 to the present was considered

Chemical composition and prebiotic effect of the fruit of Prunus spinosa L., Rosaceae

The blackthorn is widespread across temperate Europe and also occurs in the Near East and Africa. The fruit is traditionally used in the treatment of digestive, respiratory and kidney disorders. The aim of the study was to investigate composition and the antibacterial activity of methanol extract of blackthorn fruit, and potential prebiotic effect on selected probiotic microorganisms. The blackthorn fruit is a rich source of vitamin C (5.3 mg/100 g, determinated by titration) as well as Ca, Mg and P (106.7; 42.0 and 43.2 mg/100 g, respectively, determinated by ICP-OES). The total phenolic content was 1,235 mg gallic acid/100 g (FC method). Hydroxycinnamic acid derivatives (caffeoylquinic and feruloylquinic acids), flavonoids (glycosides of quercetin, methylquercetin and kaempferol) and anthocyanins (glycosides of cyanidin and peonidin) were tentatively identified by LC-DAD-ESI-MS. The antimicrobial activity on eight laboratory control strains of bacteria was not pronounced (MIC 1.25->5 mg/ml). On the other hand the extract (0.3-5.0 mg/ml) exhibited significant prebiotic effect on investigated probiotic strains of Lactobacillus spp., Saccharomyces boulardii and their mixtures. The stimulation of growth was in the range 4.0-52.8% in concentration dependent manner. In conclusion, significant prebiotic activity of blackthorn fruit confers new insight in blackthorn health benefits.14th Symposium on the Flora of Southeastern Serbia and Neighboring Regions, Kladovo, 26th to 29th June 202

Phenolic profile and in vitro biological activities of blackthorn fruit (Prunus spinosa L.)

The blackthorn, Prunus spinosa L. (Rosaceae) is a continental shrub widespread in Europe. The fruit is used in traditional medicine in the treatment of respiratory disorders, as well as diuretic, spasmolytic and anti-inflammatory agent. The aim of this study was to investigate the phenolic profile and in vitro biological activities: antioxidant, anti-diabetic, anti-tyrosinase, and anti-acetylcholinesterase. Furthermore the effect of blackthorn fruit extract on probiotic microorganisms was also studied. The blackthorn fruits were collected from two localities in Serbia and extracted with water, methanol and ethanol (50% V/V) at room temperature. The total phenolic contents was analysed by the Folin-Ciocalteu assay and was the highest in methanol extracts (321.36±9.13 and 217.04±17.99 mg GAE/100 g). On the contrary ethanol extracts contained the highest total flavonoids content (67.88±1.05 and 39.70±3.19 mg CE/100 g). Hydroxycinnamic acid derivatives (caffeoylquinic acid, caffeoyl hexoside) and quercetin glycosides (rutin, quercetin pentosyl-hexoside, isoquercitrin, quercetin pentoside) were detected in methanol extracts of both samples by LC-MS. Blackthorn ethanol extracts showed pronounced ferric reducing activity in FRAP test (2.80±0.07 and 1.89±0.01 mmol Trolox /100 g) and highest ability to neutralise ABTS radical (41.02±0.77 and 45.84±1.01 mmol Trolox /100 g). On the other hand methanol extract of both samples exerted significant DPPH radical scavenging activity (3.38±0.1 and 2.61±0.17 mmol Trolox/100 g) and highest activity in β-carotene/linoleic acid bleaching test (20.89±2.28 and 21.16±2.43%). Methanol extract of both samples inhibited the enzimes: α-amylase (IC50 2.05±0.05 and 1.26±0.04 mg/ml) α-glucosidase (IC50 0.63±0.02 and 0.43±0.06 mg/ml), tyrosinase (IC50 1.0±0.07 and 0.57±0.02 mg/ml), and acetylcholinesterase (IC50 0.56±0.28 and 2.16±0.56 mg/ml). In addition the methanol extracts of both samples markedly stimulated the growth of investigated probiotic microorganisms. The blackthorn fruit represents a rich source of biologically active compounds and although it is almost forgotten it should be used again in human nutrition to maintain health.UNIFood2021 Conference, 24th-25th September 2021 University of Belgrade, 2nd International UNIfood Conferenc