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Evidence and characterisation of Xanthomonas arboricola pv. juglandis causing bacterial blight of walnut in Montenegro
No full textThis study represents the first evidence of the bacterial blight caused by Xanthomonas arboricola pv. juglandis
(Xaj) on walnut trees in Podgorica (Montenegro). Disease symptoms appeared on leaves in the form of dark,
angular leaf spots surrounded by yellow-green haloes and lesions spread across the whole leaf. Isolated bacteria were
preliminarily identified using PCR with pathovar-specific primer pair XajF/XajR and further characterised based on
multi-locus sequence analysis with nine housekeeping genes (fusA, gapA, gltA, gyrB1, lepA, rpoD, dnaK, fyuA, and
gyrB2). Montenegrin walnut isolates were homogeneous among themselves and the most closely related to different
X. arboricola strains originating from Juglans regia isolated elsewhere. The pathogenicity of isolates was confirmed on
walnut leaves, fruits, and branches. All inoculations resulted in the formation of necrotic lesions that initially developed
at the site of bacteria entry, with later developing chlorotic areas on leaves along the leaf veins. This finding of Xaj causing
leaf blight symptoms on walnuts in Montenegro highlights its expanding distribution across Europe and indicates
a potential threat to walnut plantations in Montenegro
End-of-Life Management Strategies for Fe–Mn Nanocomposites Used in Arsenic Removal from Water
No full textThis study investigates the regeneration, reuse, stabilization, and environmental
safety of Fe–Mn polymer nanocomposites for arsenic (As) removal and their environmen-
tal safety. The regeneration performance of Fe–Mn polymer nanocomposites (PS-FMBO)
used in this study was assessed through batch adsorption–desorption cycles using various
eluents, including NaOH, NaOH–NaCl, and NaOH–NaOCl mixtures. The results demon-
strated that 0.1 M NaOH yielded the best regeneration performance, maintaining higher
adsorption efficiency over multiple cycles. Stronger desorption agents caused a signifi-
cant decline in removal efficiency due to possible structural degradation of the PS-FMBO
nanocomposite, suggesting that aggressive desorption conditions could compromise its
long-term effectiveness. The stabilization of PS-FMBO with cement and quicklime was
evaluated for immobilizing As, iron (Fe), and manganese (Mn). Leaching tests indicated
that the composites effectively immobilized these contaminants, with minimal leaching
observed even after prolonged aging, ensuring compliance with environmental safety
regulations. Furthermore, chitosan-based foams were analyzed for their chemical stability,
with leaching tests confirming low concentrations of As, Fe, and Mn, even under aggressive
conditions, further reinforcing the material’s safety and environmental compliance. These
findings underscore the potential of PS-FMBO composites and chitosan-based foams as
sustainable materials for hazardous waste management and eco-friendly construction ap-
plications. Their ability to immobilize contaminants while maintaining structural integrity
highlights their practical significance in reducing environmental pollution and advancing
circular economy principles
In vitro biocontrol potential of indigenous Bacillus velezensis strains in suppressing black rot disease in cabbage cv. Futoški
No full textSerbian autochthonous cabbage cv. Futoški is susceptible to various pathogens, including the bacterium Xanthomonas campestris pv. campestris (Xcc), the causal agent of black rot, resulting in significant economic losses.
This study aimed to provide an environmentally friendly solution for controlling black rot in cabbage cv. Futoški by exploring the potential of indigenous Bacillus spp. strains.
Bacillus spp. strains were isolated from the phyllosphere and rhizosphere of cabbage cv. Futoški plants, with and without black rot symptoms. The potential antagonistic activity of their whole cultures and cell-free supernatants was tested in vitro, against Xcc strain XccFC231, also isolated from the cv. Futoški. Phylogenetic analysis was performed based on concatenated sequences of the 16S rRNA, rpoB, and gyrA genes to identify the most potent biocontrol candidate(s). The presence and/or absence of lipopeptide genes in candidates was checked using specific primers, targeting the synthesis of bacillomycin D, fengycin, iturin, kurstakin, and surfactin.
Of the 115 isolated Bacillus spp. strains, 52 exhibited antagonistic activity of whole cultures, while nine (BFC3, BFC55, BFC68, BFC73, BFC81, BFC88, BFC98, BFC102, and BFC114) demonstrated activity of supernatants (Ø 12–19 mm) as well. All nine biocontrol candidates were identified as Bacillus velezensis. Except for BFC98, the rest of the candidates showed potential to produce bacillomycin D, while six strains (BFC3, BFC55, BFC68, BFC88, BFC98, and BFC102) exhibited potential for iturin production.
The nine isolated B. velezensis strains show potential for future use in managing black rot on cabbage cv. Futoški, and could potentially be used on other Brassicaceae.У књизи апстраката није наведен ISBN број
Optimizing cold sintering conditions for dense yttrium manganite ceramics
No full textHexagonal yttrium manganite (YMnO3) is a multiferroic material exhibiting both ferroelectric and antiferromagnetic properties. This coexistence allows for the possibility of magnetoelectric coupling, where magnetization can potentially be controlled by an electric field, and electric polarization can be influenced by a magnetic field. However, the application of this ceramic material is limited by the appearance of microstructural defects, such as microcracks and inter- and intragranular pores, which appear during the cooling phase following high sintering temperature.
Cold sintering is a relatively novel sintering technique that allows densification of ceramics at significantly lower temperatures (usually below 300 °C), using a transient liquid phase, typically water or another solvent, under uniaxial pressure.
The presented results show the influence of different conditions of the cold sintering method on the densification and microstructure of YMnO3 ceramics. Yttrium manganite powders were synthesized using the sol-gel, polymerization complex method from citrate precursors, and then calcinated at 900 °C for 10 h. After that, the powders were used for cold sintering under different conditions, where the rates of heating and applying pressure, duration of the process, and liquid phase amount were varied. The structural properties of YMnO3 sintered samples were examined by XRD analysis while scanning electron microscopy (SEM) was used to assess their microstructural properties
ASSESSING THE RISK OF BIRDS COLLIDING WITH HIGH VOLTAGE TRANSMISSION LINES IN PROTECTED AREAS IN SERBIA: A GIS-BASED APPROACH
No full textU ovom istraživanju je predstavljena mapa rizika za procenu opasnosti od sudara ptica sa visokonaponskim dalekovodima u zaštićenim prirodnim dobrima u Srbiji. Metodologija uključuje sistem bodovanja zaštićenih i osetljivih vrsta ptica na osnovu statusa zaštite, podložnosti sudarima i prisustva u zaštićenim područjima. Modeliranje distribucije vrsta sprovedeno je za 59 prioritetnih vrsta koristeći MAXENT algoritam, uključujući bioklimatske varijable i podatke o prisustvu vrsta na teritoriji Srbije od 2000. do 2024. godine. Dobijeni modeli su integrisani sa podacima o infrastrukturi dalekovoda i granicama zaštićenih područja u GIS-u. Mapa rizika identifikuje segmente dalekovoda visokog rizika preklapanjem modela distribucije vrsta, lokacija dalekovoda i zaštićenih područja, pružajući prostornu procenu rizika od sudara duž ~56 km visokonaponske mreže Srbije koja prolazi kroz zaštićena dobra. Ključni rezultati uključuju geografske podatke o distribuciji ciljnih vrsta, segmente dalekovoda sa povezanim prisustvom vrsta, i zaštićena područja kroz koja prolaze dalekovodi. Podaci dobijeni ovim istraživanjem predstavljaju prvu sveobuhvatnu procenu rizika od sudara ptica sa dalekovodima za elektroenergetsku mrežu Srbije. Ovakva postavka omogućava operateru mreže da proaktivno primeni mere ublažavanja poput instaliranja divertera za ptice na segmentima dalekovoda visokog rizika. Mapa takođe pokriva Srbiju i moguće je buduće planiranje trasa dalekovoda kako bi se izbegla kritična područja za zaštitu ptica. Ukupno gledano, ovaj pristup mapiranju rizika usklađuje prakse Srbije sa evropskim standardima za zaštitu ptica. Mapa pruža naučnu osnovu za donošenje odluka o merama bezbednosti ptica i doprinosi balansiranju razvoja energetske infrastrukture sa ciljevima očuvanja biodiverziteta. Metodologija se može ažurirati u svakom trenutku u zavisnosti od količine i broja dostupnih podataka.In this paper, we developed a risk map to assess the probability of bird collision hazards with high voltage power lines in protected areas in Serbia. The methodology involved scoring protected and sensitive bird species based on conservation status, collision susceptibility, and presence in protected areas. Species distribution modeling was conducted for 59 priority species using the MAXENT algorithm, incorporating bioclimatic variables and occurrence data from 2000 to 2024. The resulting models were integrated with power line infrastructure data and protected area boundaries in GIS. The risk map identifies high-risk power line segments by overlaying species distribution models, power line locations, and protected areas. It provides a spatial assessment of collision risk across Serbia’s ~56 km high-voltage network in protected areas. Key outputs include geographic data on target species distributions, power line segments with associated species presence, and protected areas intersected by power lines. This is the first comprehensive assessment of the risk of bird collisions in protected areas for the Serbian power grid. It enables the grid operator to proactively implement mitigation measures like installing bird diverters on high-risk segments. The map also supports future grid planning to avoid critical areas for bird conservation. Overall, this risk mapping approach aligns Serbia’s practices in line with European standards for bird protection. It provides a scientific basis for decision-making on bird safety measures and contributes balance energy infrastructure development with biodiversity conservation goals. The methodology can be updated as new data becomes available to refine risk assessments over time
Rare-earth-doped barium cerate as high-temperature water vapor sensors
No full textMixed oxides with perovskite structure, such as doped BaCeO3 and BaZrO3, have been widely investigated as high-temperature proton conductors. Due to their ability to conduct protons at high temperatures and in humid atmospheres, they are mostly considered materials for solid oxide fuel cells. However, little attention has been paid to their water vapor-sensing properties at higher temperatures.
In this study, BaCe0.9Y0.1O3–δ, BaCe0.9Eu0.1O3–δ, BaCe0.9Nd0.1O3–δ, and BaCe0.9Dy0.1O3–δ powders were synthesized by the self-combustion method. They were processed into porous thick porous films to investigate the water vapor sensing properties at 400–700 ºC. The response value was expressed as an impedance ratio in dry and wet argon (ZdryAr / ZwetAr). All the samples showed stable response values and could detect 0.03 vol% of water vapor at 550 ºC within the impedance range of 103 Ω at 100 Hz. The maximal response value of 3.41 reached the BaCe0.9Eu0.1O3–δ sample at 550 ºC and p(H2O) = 4.28 kPa. The average response time was several seconds and only slightly changed with the material type and experimental conditions. The recovery time depended on temperature and the ZdryAr / ZwetAr ratio. It was less than a minute (55 s) for the BaCe0.9Eu0.1O3–δ sample at a 200 cm3/min flow rate, 550 ºC, and p(H2O) = 2.14 kPa. All the samples exhibited a high degree of reproducibility of the response values after multiple exchanges of wet and dry atmospheres at different temperatures.https://www.ecers2025.org
Silicon mitigates Macrophomina phaseolina root infection in sugar beet
No full textMacrophomina phaseolina is a soil-borne, cosmopolitan fungal pathogen that causes stem and root rot,
seedling blight, or charcoal rot in various plant species. In sugar beet, M. phaseolina has been
considered a minor root pathogen, typically affecting weakened, injured, or stressed plants. However,
in recent years, likely due to climate change, its economic impact on sugar beet production has increased
worldwide. In Serbia, it has become one of the most significant sugar beet root rot pathogens. The aim
of this study was to investigate the effect of silicon (Si) supply on M. phaseolina root infection in
hydroponically grown sugar beet. Sugar beet seedlings (Beta vulgaris L., cv. Eduarda) were inoculated
with M. phaseolina and divided into two groups: –Si (grown in a standard Si-free nutrient solution) and
+Si (grown in the same solution supplied with 1.5 mM Si (OH)₄). Control (non-inoculated) seedlings
were also grown in either –Si or +Si conditions. Root infection by M. phaseolina was detected
microscopically and further confirmed using PCR. DNA sequences of isolates used in this study were
multiplied with conservative set of primers and M. phaseolina was confirmed. Identification of M.
phaseolina was also confirmed by morphological characteristics. In non-inoculated plants, Si supply
promoted root growth and development, evidenced by increased dry biomass, root volume, and lateral
root formation, compared to –Si control. M. phaseolina-inoculated roots showed clear signs of damage,
including a two-fold increase in root leakage (measured as electrical conductivity of the root solution)
and reduced root volume and biomass. Addition of Si significantly mitigated these effects, enhancing
root growth and reducing leakage to the levels comparable with non-inoculated plants. Additionally,
supply of Si lowered calcium (Ca) to Si ratio in both non-inoculated and inoculated roots, while also
decreasing Ca concentration by half, which likely indicates restructuring of root cell walls. This study
provides the first evidence that Si supplementation can effectively reduce M. phaseolina root infection
in sugar beet. Moreover, it confirms the beneficial effects of Si on overall plant performance, especially
root development, even under non-stressed conditions
Антиоксидативни одговор кукуруза гајеног у пољу након фолијарног третмана са наранџастим угљеничним тачкама
No full textНаночестице могу играти важну улогу у побољшању продуктивности биљака и агроиндустрији. Наранџасте угљеничне тачке (енгл. оrange-carbon dots, o-CDs) могу повећати фотосинтетске параметре и последично принос усева. Због мале величине (~ 2 nm) и амфифилних својстава, o-CDs лако пролазе кроз поре ћелијског зида. Стога је нужно истраживање потенцијалног оксидативног стреса индукованог применом o-CDs у биљкама. Ово истраживање извештава о ефекту фолијарно примењених o-CDs (1 and 5 mg/L) на параметре секундарног метаболизма у листовима кукуруза, укупну антиоксидативну активност (енгл. total antioxidative activity, TAA) и укупан садржај фенола (енгл. total phenolic content, TPC). Биљке су гајене у пољу током целог животног циклуса, а узорци листова су сакупљани након три примењена циклуса третмана. Оба испитана параметра су индикатори оксидативног поремећаја у биљкама. TAA одражава комбиновани допринос антиоксиданата мале молекулске тежине, укључујући фенолне киселине, витамине, шећере, итд. TPC представља нивое фенолних секундарних метаболита, који су круцијални за регулацију одбрамбеног система биљке. Оба параметра су одређивана спектрофотометријски. Резултати су показали да је TPC био повећан након третмана са 1 mg/L o-CDs, док се TAA није разликовао од контроле. Повећање TPC у листовима кукуруза третираних са 1 mg/L o-CDs може указати на већи одбрамбени капацитет у листовима. Добијени резултати потврђују нетоксичност и безбену примену о-CDs за третман биљака у пољопривреди у сврху повећања фотосинтетске ефикасности и приноса усева
Yttrium-Induced Transformation of Schiff Bases: From Coordination Attempts to Crystallographic Analysis of Reaction Products
No full textSchiff bases and their coordination compounds are widely known for their diverse biological and catalytic applications.[1] Yttrium(III) salts, especially in the form of Lewis acids such as Y(OTf) , have been used in various organic transformations, including ring closures, additions and rearrangements.[2] In this study, two novel Schiff base ligands, N¹,N²-bis(anthracene-9-methylene)-4-methylbenzene-1,2-diamine and N¹,N²-bis(anthracene-9-methylene)-4-chlorobenzene-1,2-diamine, were synthesised in high yields by condensation reactions and fully characterised by IR, ¹H and ¹³C NMR and mass spectrometry. Subsequent reactivity studies with yttrium(III) salts revealed an unexpected transformation pathway. Instead of forming coordination complexes, the reaction proceeded through yttrium-catalyzed intramolecular rearrangement, yielding structurally modified products with imidazole-like five-membered heterocycles, with simultaneous claveage of an anthracene moiety. These results indicate that the pronounced steric bulk of the ligands probably inhibited metal coordination and redirected the reaction toward skeletal reorganization. This behavior is consistent with the known catalytic profiles of yttrium(III) species in organic media. These results indicate that yttrium can catalytically induce structural reorganization in sterically demanding Schiff bases. The resulting compounds were isolated in moderate yield and subjected to comprehensive structural elucidation by single-crystal X-ray diffraction (SC-XRD), which revealed well-defined molecular architectures, including solvent co-crystallization (methanol) in one case. Complementary spectroscopic methods (IR, NMR, MS) supported the proposed structural changes. These results emphasize the potential of yttrium(III) as a catalytic agent capable of inducing non-traditional transformation pathways in sterically loaded Schiff bases. Further studies are underway to investigate the influence of stoichiometry, temperature, and reaction time on the observed catalytic behavior
Predicting student performance using the Multilayer Perceptron method including traditional evaluating technique
No full textThe research paper examines student performance in higher education, proposing the application of the Multilayer Perceptron (MLP) method for grade classification and performance prediction. Our objectives include monitoring student knowledge levels and predicting outcomes based on various predictor factors. This approach can help identify students at risk, evaluate teaching methods, and encourage engagement during the course. The results highlight the effectiveness of MLP in monitoring and predicting student progress, improving the objectivity of assessment