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Two Age Groups of Adult Pikeperch (Sander lucioperca) as Bioindicators of Aquatic Pollution
Get PDFPikeperch of age classes 3+ and 4+ were collected from the Garaši reservoir (Serbia) to analyze their bioindicator potential and compare their possible differences. Concentrations of 26 elements were determined in gills, muscles, and liver by inductively-coupled plasma optical emission spectrometry (ICP-OES) and of 17 organochlorine pesticides (OCPs), and six polychlorinated biphenyls (PCBs) in muscle by gas chromatography with mass spectrometric detection (GC-MS). Histopathological changes in the liver and gills were analyzed as biomarkers of general fish health. Only the concentrations of Cd, Na, and P in the muscles differed significantly. The OCPs and PCBs concentrations were below the detection limits, so fish meat consumption does not pose a risk concerning these substances. Hg and Cd exceeded the maximum allowed concentrations in some 4+ individuals, probably due to biomagnification. Gills were the most affected by metal exposure in both age classes. Histopathological changes and indices were minor and did not differ significantly between age classes, suggesting that pollution did not affect the morphology and structure of gills and liver. There were no significant correlations between elemental accumulation and fish condition or between histopathological scores. Therefore, both age classes can be used as bioindicators of pollution
Utvrđivanje genetičke strukture populacija Acidovorax citrulli u Srbiji
No full textBakteriozna mrljavost plodova lubenice (Acidovorax citrulli) predstavlja širom sveta ozbiljnu pretnju uključujući uzgajivače i proizvođače semena i rasada gajenih vrsta biljaka iz porodice Cucurbitacae. Krajem 1980-ih, bakterija A. citrulli se nakon epidemijskih pojava na lubenici u SAD proširila na druga područja i useve (dinja, tikva, bundeva, krastavac). Do danas su opisane dve genetički različite populacije A. citrulli. U Srbiji je prvi nalaz A. citrulli zabeležen 2014. godine na lubenici u lokalitetima Bačke i Srema. Međutim, uprkos sprovedenim eradikativnim merama i naporima u upravljanju ovim patogenom, ponovo je detektovan 2018., 2021., i 2022. godine na području Mačve i Srema. U cilju boljeg razumevanja genetičke strukture populacija A. citrulli prisutnih u Srbiji, u ovom radu je korišćena analiza sekvenci više genskih lokusa (MLSA) primenom konzerviranih gena i gena virulentnosti. Tokom rada korišćena su četiri reprezentativna soja A. citrulli, pod šiframa Ac414 (Čelarevo, 2014), Ac818 (Šabac, 2018), Ac221 (Ašanja, 2021) i Ac322 (Hrtkovci, 2022), odabrana na osnovu prethodnih rezultata dobijenih umnožavanjem ponavljajućih sekvenci DNK (rep-PCR). Za MLSA je korišćeno devet gena, i to osam konzervativnih (gltA, gmc, gyrB, lepA, phaC, pilT, trpB, ugpB) i jedan gen virulentnosti (Aave_1548). PCR program se sastojao od inicijalne denaturacije (5 min na 95 °C), praćene sa 30 ciklusa denaturacije (30 s na 95 °C), hibridizacije (30 s na 60 °C za konzervativne gene i 55 °C za gen virulentnosti Aave_1548) i elongacije (30 s za konzervativne gene i 90 s za gen Aave_1548 na 72 °C); i finalne elongacije (5 min na 72 °C). Amplifikovani produkti su sekvencirani u Eurofins Genomics (Hamburg, Nemačka). Kvalitet dobijenih sekvenci je manuelno pregledan, nakon čega je za svaki od četiri testirana soja napravljena multigenska sekvenca na osnovu svih sekvenciranih gena. Multigenske sekvence testiranih i referentnih sojeva A. citrulli preuzetih iz baze podataka Nacionalnog centra za biotehnološke informacije (NCBI) korišćene su za konstruisanje „Neighbor-joining” filogenetskog stabla. Na osnovu rezultata filogenetske analize, dokazano je da sojevi A. citrulli izolovani iz prirodno zaraženih plodova lubenice u Srbiji (2014-2022) pripadaju dvema reprezentativnim genetičkim grupama opisanim u svetu (grupe I i II). Grupi I su pripadali sojevi izolovani 2021. i 2022. godine, a grupi II sojevi izolovani 2014. i 2018. godine. Rezultati dobijeni u ovom radu ukazuju na puteve introdukcije i širenja A. citrulli u Srbiji
Proučavanje prouzrokovača vlažne truleži paprike i mrkve u Vojvodini
No full textVeliki ekonomski značaj u gajenju brojnih biljnih vrsta, a posebno korenasto-krtolastih, imaju bakterije iz rodova Pectobacterium i Dickeya, prvobitno opisane kao rod Erwinia. Ove bakterije prouzrokuju bolest tzv. vlažnu trulež. Štete nastaju usled propadanja zaraženih plodova, krtola i mesnatog korena. Iako ovi patogeni mogu da prouzrokuju velike štete tokom proizvodnje, ipak najveće nastaju tokom skladištenja. Primenom metode sekvenciranja DNK genoma, taksonomija rodova Pectobacterium i Dickeya je u prethodnoj deceniji značajno izmenjena,usled čega je i pripadnost pojedinih, već opisanih sojeva vrstama iz ovih rodova iznova determinisana. Takođe, ova metodologija doprinela je otkrivanju velikog broja novih vrsta bakterija ovih rodova. Tako, rod Pectobacterium do danas broji 20 vrsta, a rod Dickeya najmanje 10. S obzirom na učestale taksonomske promene, cilj ovog rada je bio da se izoluju i identifikuju prouzrokovači vlažne truleži paprike i mrkve kako bi se utvrdio genetički diverzitet novoizolovanih bakterijskih populacija. Tokom septembra 2022. godine, na lokalitetu Rimski Šančevi prikupljeni su oboleli uzorci plodova paprike sa simptomima vlažne truleži, a na lokalitetu Futog uzorci korena mrkve. Simptomi su se javljali u vidu razmekšavanja i propadanja plodova, uz prisustvo karakterističnog, neprijatnog mirisa. Izolacije su vršene sa prelaznih zona između obolelog i zdravog tkiva, na podlogu sa saharozom i peptonom. Bakterijske kolonije beličasto krem boje,
glatke, blago ispupčene su se javljale 48 h nakon izolacije i inkubacije na 26 °C. Patogenost odabranih izolata dokazana je na zrelim plodovima paprike, korenu mrkve, kao i krtolama krompira. Analiza sekvenci više genskih lokusa (MLSA) vršena je primenom šest konzerviranih gena dnaX, gapA, icdA, mdh, recA i rpoS. BLASTn analiza Nacionalnog centra za biotehnološke informacije (NCBI) je pokazala da izolati poreklom sa paprike pripadaju bakteriji Pectobacterium brasiliense, sa procentom identiteta od 98,96% (dnaX) do 100% (gapA). Izolati poreklom sa mrkve su identifikovani kao Pectobacterium carotovorum, sa
procentom identiteta od 100%, na osnovu sekvenci svih šest analiziranih gena. Ove bakterije su u Srbiji prethodno determinisane i opisane kao patogeni krompira, a P. carotovorum i kao patogen kupusa
Practising Dialectical Materialism: The Balkan House and Architecture in Socialist Yugoslavia
No full textThis article examines relationships between architecture and ideology in socialist Yugoslavia by exploring the cultural interpretation and appropriation of the Balkan house in achieving modern, specifically Yugoslav architectural expression. Through the contextualization of the period's different narratives on the Ottoman vernacular and various architectural designs related to it, the aim is to demonstrate how Yugoslav architects relied on Marxism to appropriate vernacular architecture into the modernist discourses. Dialectical materialism was used as a key for the interpretation of the opposition between what was seen as the negative and positive elements of the Balkan house, which challenged banal polarization between the traditional and modern and led to a more nuanced understanding of backwardness and progress in vernacular architecture. The idea of architectural metamorphoses of vernacular to modern forms was justified by evolution and revolution, the basic concepts of the Marxist understanding of processes in society and culture. The Yugoslav interest in the Balkan house represented a living, perceivable example of how the relationships between tradition and modernity, the past and the present, as well as men and their environment, became incorporated into new architecture of ‘socialism with a humane face’, which stood at the heart of Yugoslav social and political experiment
Exploring denitrification and anammox processes in the saturated zone of passively operated vegetated biofiltration systems
No full textVegetated biofiltration systems (VBS) are common nature-based solutions (NBS) for urban water treatment, but their performance in treating nitrogen-rich wastewater is yet to be explored. This study investigated the submerged zone (SZ) component of VBS, for its ability to treat nitrogen through traditional denitrification, as well as the anaerobic ammonium oxidation (anammox) process that was rarely studied in NBS. A two-phase column-based experiment was conducted: (1) denitrification phase, to explore the impact of different carbon sources (hardwood chips, softwood chips, walnut shells), retention time and dissolved oxygen (DO) on denitrification; and (2) anammox phase, to identify whether the anammox process could occur in passively operated VBS. The results show that the VBS was able to treat nitrogen rich wastewater (with 80–100 mg L−1 total nitrogen – TN) in both phases (average TN removal rates of 58.0 ± 16.4%). Carbon sources had significant influences on TN and NO3–N removal in the denitrification phase (p 10%), with Comamonadaceae_unclassified being the most abundant (average 8.3%) across all media types. A suspected anammox genus SM1A02 was found in the systems, but at very low abundance levels (up to 0.137%), which may indicate the presence of the anammox process in the passively operated VBS
Activity Coefficients of the System {yNaCl+(1–y)NaH2PO4}(aq) at T = 298.15 K
No full textZero-current cell-potential measurements were used to determine the solution activity coefficient in a ternary system {yNaCl + (1-y)NaH2PO4}(aq) at a temperature T = 298.15 K, in the total ionic strength range I = (0.1-1.0) molkg-1. The Na–ISENaCl(mNaCl), Na2HPO4 ( )AgAgCl, cell was used where m_NaCl and m_(NaH_2 PO_4 ) are the stoichiometric molalities of the NaCl and NaH2PO4 electrolytes in the mixture. The ionic strength fraction of NaCl in the total ionic strength of the mixed solution was y = (0.199;0.310; 0.4101; 0.5051; 0.6090; 0.7776; 0.9037). The standard electrode potential of the electrode pair is Eo = 23.22737 mV. The values of the mean ionic coefficients of NaCl in the mixed electrolyte solution, γ_(±NaCl) , were estimated using Nerst equation (1): (1)
where E_m is the electrode potential of the cell, γ_(〖±NaH〗_2 PO_4 ) is mean ionic activity coefficient of NaH2PO4 in the mixture and Kpot is selectivity coefficient having values less than K^pot<10^(-4) and therefore, was neglected.
The ionic strength of the solution is I =〖 m〗_NaCl+m_(NaH_2 PO_4 ) whereas the ionic strength fraction of NaCl is: y=〖 m〗_NaCl/I. To generate a set of parameters for the system {yNaCl + (1-y)NaH2PO4}(aq) that can be applied in the investigated range of mixed solution ionic strengths, Pitzer models[1] were used to fit the experimental data, represented in Figure 1. Parameter values for the pure electrolyte solutions of the second and third virial coefficients, B_NaCl 〖,B〗_(NaH_2 PO_4 ),〖 C〗_NaCl^T,〖 C〗_(NaH_2 PO_4)^T, respectively, that are mixture components, were taken from literature[2,3]. The treatment of experimental data using Pitzer’s model yielded the following values of the mixing parameters θ_(Cl,〖H_2 PO〗_4 ) = - 0.710 and Ψ_(Na,Cl,〖H_2 PO〗_4 ) = 0.1269.The experimental and calculated values of the thermodynamic properties of the studied system were in excellent agreement, with standard deviation s.d. (NaCl)= 0.004
Quantitative traits of white cabbage cultivars in association with two biofertilisers - Abstract
Get PDFCabbage is one of the most important vegetables from Brassicaceae family to which
biofertilisers is increasingly applied following the current trend in the cabbage organic
farming. The main goal of our study was to examine whether solely applicated biofertilisers
enhance head weight and other morphological parameters in cabbage. Experiment with three
Bejo Zaden cultivars ('Farao' F1, 'Tiara' F1, and 'Excalibur' F1) were conducted under the open
field conditions from April to June 2019. Two different microbiological fertilisers, Organic
balance and FitoHelp, were applied foliar, six times during the vegetation period, with a
battery sprayer. After harvest, several parameters were estimated: head weight, width and
height, number of leaves, internal core height and width. The results showed the highest
value of head weight (1264.89 g), head width (15.06 cm), head height (15.57 cm), number of
leaves (22.56), internal core height (8.01 cm) and internal core width (3.51 cm) in cultivar
'Excalibur' F1 compared to other two cultivars for fresh market. Application of both fertilisers
led to increased levels of all tested parameters compared to control. Furthermore, fertiliser
Organic balance showed the highest impact on all tested parameters, resulting in increasing
value of head weight by 78.6%. This study revealed that mixed culture fertiliser showed
greater impact in terms of head weight, number of leaves, and internal core width compared
to fertiliser containing a single strain of bacteria. Accordingly, with an exception in head and
internal core height, all examined factors showed statistically significant impact on tested
parameters, including their interaction
Influence of biofertilizers on yield and quality of lettuce grown in the open field
Get PDFThe production of lettuce is very profitable due to the short vegetation period and the
possibilities of its cultivation throughout the year. On average, the salad contains 94% water,
2% sugar, 0.6% crude cellulose, 0.6% mineral matter and 1.2% crude protein. It is rich in
vitamins C, B1 and B2, and many mineral elements. Great influence on the quantitative and
qualitative properties of lettuce in addition to the variety and production conditions has a
proper diet. The application of mineral fertilizers results in high yields, but their inadequate
application can cause various problems such are: decrease in dry matter content, deterioration
of salad quality, increase in soil acidity, degeneration of physical properties, increase in
erosion and instability in land aggregates. In order to reduce the use of chemicals and increase
the yield in the same time, the improvement of plant production is moving in the direction of
introducing biofertilizers. In recent years there has been a trend of decreasing the usage of
mineral nutrients, primarily nitrogen, phosphorus and potassium (Haytova, 2013), in which
bio stimulators play a significant role. Therefore, the goal was to determine the impact of
biofertilizers on the yield and quality of lettuce and to investigate the possibility of
streamlining the crop by using biostimulators in lettuce nutrition. The two-factor experiment
was set on a private plot in district Vranjes, East Sarajevo by using the randomized block in 3
replications. The highest yield of lettuce was obtained in the variant with the application of
the biofertilizer Bioplant flora (630.50 g – please state the unit), whereas the lowest was
recorded in the control variant of fertilization (468.00 g). The highest percentage of dry matter
was noted in the third variant of fertilization (Bioplant flora) in the variety Majska kraljica
(6.45%), whilst the lowest percentage was reached in the control variant of the same variety
(4.14%)
WEPASS Project - Making the Iron Gate Dams passable for migratory fish
Get PDFEuropean rivers are obstructed by more than one million barriers that have resulted in excessive loss of river continuity. On the main course of the Danube River there are 83 longitudinal continuity interruptions, out of which 65 dams are used for hydropower (ICPDR 2022a). The Iron Gate Hydropower and Navigation System is one of the largest river engineering projects undertaken in Europe, with the dams mainly built to provide hydropower and flood protection, and to facilitate navigation along the Danube. These infrastructures represent introduced barriers to fish migration. Hence, ensuring passage opportunities for fish at the Iron Gate dams is considered to be of major importance for the conservation of migratory fish populations in the Danube River basin. Restoration of river continuity at these sites would reopen an additional 900 km for migration up to the Gabčikovo dam, providing suitable habitats and spawning grounds along the Danube and its tributaries. Knowledge about fish behavior and movements in the vicinity of these river infrastructures is required to build effective up- and downstream passage facilities to allow the migration of fish species. To gain insight in the approach routes and aggregation areas a refined approach to acoustic telemetry is employed to support migration facilitation
Carbon Stocks, Sequestration Rate and Efficiency over 50 Years of Increasing Mineral N Fertilization
No full textMicrobially mediated soil organic matter is an extremely sensitive pool that indicates subtle changes in the quality parameters. The calculation of different carbon pools (organic carbon—OC, labile carbon—PMC, light carbon—LFC and microbial carbon—MBC), their sequestration rate (Csr) and efficiency (Cse), as affected by 50 yrs. of mineral fertilization, was carried out. The C sequestration rates between the fertilized plots were not significantly different except for the control plot. The sensitivity index, which indicates the response of soil organic matter to changes in different carbon fractions, demonstrated a strong correlation with the amount of light-fraction organic matter (OM). The use of mineral N over 50 years resulted in increase of soil labile C, but did not result in greater C sequestration efficiency. The results give a deeper insight into the behavior of carbon pools and can serve as a reliable basis for further studies focused on neutral carbon emissions and effective C sequestratio