183 results on '"Spasić, Slađana"'
Search Results
2. Modeling of Orange Carbon Dots-CO2 Interaction and Its Effects on Photosynthesis and Productivity in Maize and Green Beans
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Milenković, Ivana, Zhou, Yiqun, Borišev, Milan, Serafim, Leonardo, Chen, J.I., ElMetwally, A.E., Spasić, Slađana, Algarra, Manuel, del Valle Martinez de Yusso, Maria, Prabhakar, R, Leblanc, Roger, Radotić, Ksenija, Milenković, Ivana, Zhou, Yiqun, Borišev, Milan, Serafim, Leonardo, Chen, J.I., ElMetwally, A.E., Spasić, Slađana, Algarra, Manuel, del Valle Martinez de Yusso, Maria, Prabhakar, R, Leblanc, Roger, and Radotić, Ksenija
- Abstract
Crop yield increases with a sustained increase in leaf photosynthesis. Due to many limitations, plants do not sufficiently use their photosynthetic capacity. Carbon dots (CDs) have a high light harvest capability, which may be used to improve the photosynthesis efficiency of plants. In this study, nontoxic orange CDs (o-CDs) were foliarly applied to boost the maize (Zea mays L.) and green beans (Phaseolus vulgaris L.) productivity in the field. Leaves of both plant species were sprayed three times with 1 and 5 mg/L of the o-CDs aqueous solutions in equal intervals during the vegetative growth stage until flowering. To find the best geometries for CO2 adsorption on o-CD, modeling of o-CDs-CO2 interaction was performed. Photosynthesis parameters and fruit yield were measured during plant growth. Total phenolic content and antioxidative activity were monitored as oxidative stress indicators. Computational simulations and spectroscopic measurements suggest that o-CDs, acting as a “CO2 delivery” system, can enhance photosynthetic efficiency. Photosynthesis was enhanced in both plant species, but only green beans showed an increased fruit yield. CO2 use in tested species was discussed in light of two mechanisms. Plant species show different, but no significant antioxidative responses. The chemical surface composition has shown that o-CDs were not contained in either the leaves or fruits of the treated plants. The results indicate that o-CDs may be applied as a simple and safe biostimulator on plants. That could have an environmental benefit in capturing CO2 in the atmosphere.
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- 2024
3. The effects of nembutal on the intracerebellar EEG activity revealed by spectral and fractal analysis
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Stojadinović Gordana, Martać Ljiljana, Podgorac Jelena, Spasić Slađana Z., Petković Branka, Sekulić Slobodan, and Kesić Srđan
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nembutal ,intracerebellar eeg ,spectral analysis ,fractal analysis ,Biology (General) ,QH301-705.5 - Abstract
A detailed analysis of the anesthetic-induced modulation of intracerebellar electrical activity is an important step to understand the functional brain responses to anesthesia. We examined the electrical activity recorded from different cortical layers: molecular layer (ML), Purkinje cell layer (PCL), granular layer (GL) and the white matter (WM) in the vermian part of rat cerebellar lobule V during Nembutal anesthesia using spectral and fractal analysis. Spectral analysis revealed a difference in the mean relative power of delta (0.1-4.0 Hz) and theta (4.1-8.0 Hz) frequencies through the cerebellar layers. Compared to the ML, delta activity increased significantly in the GL, while theta activity decreased in the GL and the WM. Fractal analysis revealed that the mean value of Higuchi’s fractal dimension (HFD) increased, starting from the ML to the WM. Theta activity exhibited a negative correlation with the HFD value in the ML. In contrast, the gamma activity showed a positive correlation with the HFD value in the ML and the GL. The combined use of spectral and fractal analyses revealed that Nembutal displays different effects on rat cerebellar electrical activity, which largely depends on the neurochemical and electrophysiological organization of the cerebellar layers.
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- 2020
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4. Effects of mine tailing and mixed contamination on metals, trace elements accumulation and histopathology of the chub (Squalius cephalus) tissues: Evidence from three differently contaminated sites in Serbia
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Rašković, Božidar, Poleksić, Vesna, Skorić, Stefan, Jovičić, Katarina, Spasić, Slađana, Hegediš, Aleksandar, Vasić, Nebojša, and Lenhardt, Mirjana
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- 2018
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5. Metal Accumulation in Muscle and Liver of the Common Nase (Chondrostoma nasus) and Vimba Bream (Vimbavimba) from the Danube River, Serbia: Bioindicative Aspects
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Subotić, Srđan, Višnjić-Jeftić, Željka, Đikanović, Vesna, Spasić, Slađana, Krpo-Ćetković, Jasmina, and Lenhardt, Mirjana
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- 2019
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6. Changes to fish assemblage following the selective removal of black bullhead (Ameiurus melas)
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Jaćimović, Milica Lj., primary, Smederevac‐Lalić, Marija M., additional, Nikolić, Dušan, additional, Cvijanović, Gorčin D., additional, Spasić, Slađana Z., additional, Višnjić‐Jeftić, Željka V., additional, Skorić, Stefan B., additional, and Krpo‐Ćetković, Jasmina, additional
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- 2023
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7. Tracking and forecasting of students progress using Multiple-Criteria Decision Making and kNN methods
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Spasić, Slađana, Tomašević, Violeta, Spasić, Slađana, and Tomašević, Violeta
- Abstract
The paper discusses a problem in higher education related to students' progress and performance in exams. During the semester, every student would benefit from information about whether their work on the course is sufficient to achieve the desired result on the final exam. If it was pointed out to them at the right moment that success in the subject is likely to be absent, it could encourage them to increase efforts for the rest of the semester and thus in the end achieve their goal. However, if a bad result is expected for most participants, a change in the teaching method should be considered. Therefore, in this research, two aims have been set: to determine the moment during the semester when it can be said that a certain student will not successfully complete the course and to check that the teaching methods are appropriate. In order to give advice to the student in a timely manner, at certain moments during the semester, it is necessary first to diagnose the level of their knowledge, and then make a prediction of the expected result on the exam. In the solution proposed in this paper, in five time moments (t2,...,t6) the student's knowledge is assessed using the Multiple-Criteria Decision Making (MCDM) method - PROMETHEE II, which considers four criteria (attendance, activity, homework, and test), and the teacher's preferences. Thus, a progress function for a given student is obtained, which shows how they are progressing toward the set goal. Based on the values of the progress function in milestones t2-t6, student achievement is categorized through grades. In this investigation, we have used the k-Nearest Neighbors (kNN) Algorithm for grade classification. Our findings clearly justify that MCDM and kNN models are appropriate for tracking, classifying, and forecasting student grades.
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- 2023
8. Changes to fish assemblage following the selective removal of black bullhead (Ameiurus melas)
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Jaćimović, Milica, Smederevac-Lalić, Marija, Nikolić, Dušan, Cvijanović, Gorčin, Spasić, Slađana, Višnjić Jeftić, Željka, Skorić, Stefan, Krpo-Ćetković, Jasmina, Jaćimović, Milica, Smederevac-Lalić, Marija, Nikolić, Dušan, Cvijanović, Gorčin, Spasić, Slađana, Višnjić Jeftić, Željka, Skorić, Stefan, and Krpo-Ćetković, Jasmina
- Abstract
1. Black bullhead is among the most abundant and successful non-native fish species in European freshwaters. A number of studies have indicated that its physical removal could be a potential solution to minimize possible negative impacts that it may have on native fishes; however, so far there have been no field studies to confirm this. 2. This study quantified population dynamics of both native and non-native fishes in a small slow-running lowland river within the Ponjavica Nature Park in Serbia before and after the black bullhead removal with fyke-nets, which proved to be an efficient tool for this purpose. 3. The removal of black bullhead resulted in statistically significant changes in two native species abundance – an increase of rudd (Scardinius erythrophthalmus) (by 5.3 times), and a decline of bleak (Alburnus alburnus) (by 2.3 times). 4. Significant increase was observed in three non-native fish species: the abundances of topmouth gudgeon (Pseudorasbora parva), pumpkinseed (Lepomis gibbosus), and Prussian carp (Carassius gibelio) increased 25.5, 4.9, and 4.2 times, respectively. 5. There were also substantial changes in the diversity of the fish assemblage after the black bullhead removal, illustrated by changes in diversity indices: Shannon's index doubled, while the Simpson’s dominance index decreased threefold. 6. The catch-per-unit-effort and the biomass-per-unit-effort values indicated the dominance of the black bullhead in the fish assemblage. YOY/adult ratio did not vary in relation to abundance, which confirmed that black bullhead might not compensate for fishing mortality with the increased recruitment. 7. The results suggest that black bullhead plays a significant role in structuring the fish assemblage and that its removal may have both positive and negative effects on species abundance and diversity. These findings can contribute to the conservation of native fish species and improvement of future management programs.
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- 2023
9. Trans-generational effect of cerium oxide-nanoparticles (nCeO2) on Chenopodium rubrum L. and Sinapis alba L. seeds
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Milenković, Ivana, Baruh Krstić, Maria, Spasić, Slađana, Radotić, Ksenija, Milenković, Ivana, Baruh Krstić, Maria, Spasić, Slađana, and Radotić, Ksenija
- Abstract
Cerium oxide nanoparticles (nCeO2) are interesting nanomaterials due to their redox properties. Their wide application could result in unexpected consequences to environmental safety. Unlike acute toxicity, the trans-generational effects of carbohydrate-coated nCeO2 in the environment are still unknown. The main aim of this study was to investigate the effect of treating maternal plants of Chenopodium rubrum L. (red goosefoot) and Sinapis alba L. (white mustard) with uncoated (CeO2) and glucose-, levan-, or pullulan-coated nCeO2 (G-, L-, or P-CeO2) during seed germination on morphological and physiological characteristics of produced seeds in two subsequent generations. The plant response was studied by measuring germination percentage (Ger), total protein content (TPC), total phenolic content (TPhC), total antioxidative activity (TAA), and catalase (CAT) activity. Results showed that maternal effects of the different nCeO2 treatments persist to at least the second generation in seeds. Generally, C. rubrum was more sensitive to nCeO2 treatments than S. alba. The coated nCeO2 were more effective than uncoated ones in both plant species; L- and P-CeO2 were the most effective in S. alba, while CeO2 and G-CeO2 had a dominant impact in C. rubrum. Enhanced germination in all tested generations of S. alba seeds recommends nCeO2 for seed priming.
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- 2023
10. Auxin‑ and pH‑induced guttation in Phycomyces sporangiophores: relation between guttation and diminished elongation growth
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Živanović, Branka D., Ullrich, Kristian, Spasić, Slađana, Galland, Paul, Živanović, Branka D., Ullrich, Kristian, Spasić, Slađana, and Galland, Paul
- Abstract
Guttation, the formation of exudation water, is widespread among plants and fungi, yet the underlying mechanisms remain largely unknown. We describe the conditions for inducing guttation in sporangiophores of the mucoracean fungus, Phycomyces blakesleeanus. Cultivation on peptone-enriched potato dextrose agar elicits vigorous guttation mainly below the apical growing zone, while sporangiophores raised on a glucose-mineral medium manifest only moderate guttation. Mycelia do not guttate irrespective of the employed media. The topology of guttation droplets allows identifying the non-growing part of the sporangiophore as a guttation zone, which responds to humidity and medium composition in ways that become relevant for turgor homeostasis and thus the sensor physiology of the growing zone. Apparently, the entire sporangiophore, rather than exclusively the growing zone, participates in signal reception and integration to generate a common growth output. Exogenous auxin applied to the growing zones elicits two correlated responses: (i) formation of guttation droplets in the growing and transition zones below the sporangium and (ii) a diminution of the growth rate. In sporangiophore populations, guttation-induction by exogenous control buffer occurs at low frequencies; the bias for guttation increases with increasing auxin concentration. Synthetic auxins and the transport inhibitor NPA suppress guttation completely, but leave growth rates largely unaffected. Mutants C2 carA and C148 carA madC display higher sensitivities for auxin-induced guttation compared to wild type. A working model for guttation includes aquaporins and mechanosensitive ion channels that we identified in Phycomyces by sequence domain searches.
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- 2023
11. Trans-generational effect of cerium oxide-nanoparticles (nCeO2) on Chenopodium rubrum L. and Sinapis alba L. seeds
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Milenković, Ivana, primary, Baruh Krstić, Maria, additional, Spasić, Slađana Z., additional, and Radotić, Ksenija, additional
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- 2023
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12. Heavy metal and trace element bioaccumulation in target tissues of four edible fish species from the Danube River (Serbia)
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Subotić, Srđan, Spasić, Slađana, Višnjić-Jeftić, Željka, Hegediš, Aleksandar, Krpo-Ćetković, Jasmina, Mićković, Branislav, Skorić, Stefan, and Lenhardt, Mirjana
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- 2013
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13. Using Higuchi’s fractal dimension in fine analysis of the effects of 2.7 mT and 10 mT static magnetic fields on the complex bursting activity of the snail BR neuron
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Kesić S., Nikolić Ljiljana, Janać Branka, and Spasić Slađana Z.
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Higuchi fractal dimension ,bursting activity ,Br neuron ,static magnetic field ,Biology (General) ,QH301-705.5 - Abstract
The components of complex bioelectrical activity – action potential (AP), interspike interval (ISI) and the quiet interburst interval (IBI), along with the effects of 2.7 mT and 10 mT static magnetic fields, were identified and examined in the spontaneously active Br neuron of the subesophageal ganglion complex of the garden snail Helix pomatia by fractal analysis using Higuchi’s fractal dimension (FD). The normalized mean of the empirical FD distributions of bursting activity of the Br neuron were formed under different experimental conditions: before (Control), during (MF), and after exposure to the static magnetic field (AMF). Using the fractal analysis method for the first time, a separation of the AP, ISI and IBI components was successfully achieved. Our results show that fractal analysis with deconvolution of the normalized mean of the empirical FD distributions into Gaussian functions is a useful tool for revealing the effects of magnetic fields on the complexity of neuronal bioelectric activity and its AP, ISI and IBI components. [Projekat Ministarstva nauke Republike Srbije, br. 173027 and 173045]
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- 2014
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14. Carbohydrate-coated cerium oxide nanoparticles affect the germination of Sinapis alba and Chenopodium rubrum seeds through the generations
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Milenković, Ivana, Spasić, Slađana, Radotić, Ksenija, Milenković, Ivana, Spasić, Slađana, and Radotić, Ksenija
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- 2022
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Jaćimović, Milica, Smederevac-Lalić, Marija, Nikolić, Dušan, Cvijanović, Gorčin, Spasić, Slađana, Višnjić Jeftić, Željka, Skorić, Stefan, Krpo-Ćetković, Jasmina, Jaćimović, Milica, Smederevac-Lalić, Marija, Nikolić, Dušan, Cvijanović, Gorčin, Spasić, Slađana, Višnjić Jeftić, Željka, Skorić, Stefan, and Krpo-Ćetković, Jasmina
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- 2022
16. Circadian activity of the Wels catfish (Silurus glanis) in the Danube River
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Spasić, Slađana, Smederevac-Lalić, Marija, Lenhardt, Mirjana, Hont, Stefan, Paraschiv, Marian, Iani, I. Marian, Nichersu, Iulian, Trifanov, Cristian, Nikčević, Miroslav, Klimley, Abbott Peter, Suciu, Radu, Spasić, Slađana, Smederevac-Lalić, Marija, Lenhardt, Mirjana, Hont, Stefan, Paraschiv, Marian, Iani, I. Marian, Nichersu, Iulian, Trifanov, Cristian, Nikčević, Miroslav, Klimley, Abbott Peter, and Suciu, Radu
- Abstract
In this study, the movements and behaviour of Wels catfish (Silurus glanis, Linnaeus, 1758) were monitored during the different seasons when the water level in the river changed significantly. Wels catfish was caught on the Danube River, rkm 863, and tagged with an ultrasonic transmitter. Deployed Vemco receivers recorded detections of spatial movement between years 2015 and 2017. Our telemetry data found relatively short movements within a maximum range (~12km), but as a territorial species most of the time it was recorded by the two receivers, close to the Iron Gate dam and location where it was caught. Circadian rhythm showed that in the summer period, nocturnal activity is evident while during winter Wels catfish stayed most of the time at the same depth under the water surface. Wels catfish changed depths during the autumn and spring when more activity was recorded. The last signal received was during the winter 2017, which was period with the low temperatures and ice cover on the Danube River. This research shows the value and importance of installing coded acoustic transmitters in fish and monitoring their movement using a series of autonomous receivers deployed in the Danube River. Research by telemetry can be used to better understand fish behaviour and movements and to help improve large river management measures.
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- 2022
17. Use of non-toxic organic nanoparticles to increase productivity of growed plants and procedure for their application (P-2021/0073)
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Radotić, Ksenija, Milenković, Ivana, Borisev, Milan, Spasić, Slađana, Radotić, Ksenija, Milenković, Ivana, Borisev, Milan, and Spasić, Slađana
- Abstract
The present invention relates to organic nanoparticles, in particular orange carbon nanoparticles for use in the productivity of cultivated plants and a process for their use in increasing the productivity of cultivated plants. In particular, the present invention relates to the use of organic carbon nanoparticles used in the form of an aqueous solution to increase the content of photosynthetic pigments -chlorophyll a, -chlorophyll b and carotenoids, increase the intensity of photosynthesis and especially the yield of cultivated plants. The present invention also relates to a process for their use in increasing the content of photosynthetic pigments -chlorophyll a, -chlorophyll b and carotenoids and especially the yield of cultivated plants.
- Published
- 2022
18. Effects of selective removal of the black bullhead (Ameiurus melas) on other non-native fish populations in the Ponjavica Nature Park (Serbia)
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Jaćimović, Milica, Smederevac-Lalić, Marija, Nikolić, Dušan, Cvijanović, Gorčin, Spasić, Slađana, Višnjić Jeftić, Željka, Skorić, Stefan, Krpo-Ćetković, Jasmina, Jaćimović, Milica, Smederevac-Lalić, Marija, Nikolić, Dušan, Cvijanović, Gorčin, Spasić, Slađana, Višnjić Jeftić, Željka, Skorić, Stefan, and Krpo-Ćetković, Jasmina
- Abstract
North American black bullhead (Ameiurus melas) is an ictalurid species that has become widespread outside of its native range, causing undesirable ecological impacts. Numerous studies have suggested that its physical removal could be a way to reduce any potential detrimental effects of this species. This study measured the effects on population dynamics of both native and non-native fish species following the removal of 20,145 black bullheads from the Ponjavica Nature Park. The most significant changes between the zero-point state and the post-removal state have been recorded among the populations of non-native fish species: the abundances of topmouth gudgeon (Pseudorasbora parva), pumpkinseed (Lepomis gibbosus), and Prussian carp (Carassius gibelio) increased 25.5, 4.9, and 4.2 times, respectively. Previous research has shown that smaller black bullhead individuals enter into competitive relationships with the topmouth gudgeon, while larger individuals use the topmouth gudgeon as prey. By removing black bullhead individuals from the ecosystem, a part of the ecological niche used by both species was freed. Also, the predatory pressure on topmouth gudgeon decreased by removing larger black bullhead individuals. All these factors led to an increase in the abundance of topmouth gudgeon. Black bullhead and pumpkinseed have overlapping diets and are therefore considered competitors for food. Moreover, research on the black bullhead's feeding ecology showed that this species feeds on the pumpkinseed. When a greater number of black bullhead individuals were removed from the ecosystem, it led to an increase in the abundance of pumpkinseed. The abundance of Prussian carp also increased after the removal of the black bullhead. The Prussian carp and the black bullhead are quite similar in terms of diet habits, habitat preferences, and reproductive characteristics. Since these two species are in direct competition, the decline in the black bullhead population contributed to an
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- 2022
19. Trans-generational effect of cerium oxide-nanoparticles (nCeO2) on Chenopodium rubrum L. and Sinapis alba L. seeds.
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Milenković, Ivana, Baruh Krstić, Maria, Spasić, Slađana Z., and Radotić, Ksenija
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CERIUM oxides ,GOOSEFOOTS ,CERIUM ,SEEDS ,GERMINATION ,ENVIRONMENTAL security - Abstract
Cerium oxide nanoparticles (nCeO
2 ) are interesting nanomaterials due to their redox properties. Their wide application could result in unexpected consequences to environmental safety. Unlike acute toxicity, the trans-generational effects of carbohydrate-coated nCeO2 in the environment are still unknown. The main aim of this study was to investigate the effect of treating maternal plants of Chenopodium rubrum L. (red goosefoot) and Sinapis alba L. (white mustard) with uncoated (CeO2 ) and glucose-, levan-, or pullulan-coated nCeO2 (G-, L-, or P-CeO2 ) during seed germination on morphological and physiological characteristics of produced seeds in two subsequent generations. The plant response was studied by measuring germination percentage (Ger), total protein content (TPC), total phenolic content (TPhC), total antioxidative activity (TAA), and catalase (CAT) activity. Results showed that maternal effects of the different nCeO2 treatments persist to at least the second generation in seeds. Generally, C. rubrum was more sensitive to nCeO2 treatments than S. alba. The coated nCeO2 were more effective than uncoated ones in both plant species; L- and P-CeO2 were the most effective in S. alba , while CeO2 and G-CeO2 had a dominant impact in C. rubrum. Enhanced germination in all tested generations of S. alba seeds recommends nCeO2 for seed priming. This is the first report on the trans-generational effects of carbohydrate-coated nCeO2 on any plant seeds. We showed that maternal effects of the different nCeO2 treatments persist to at least the second generation in seeds and that enhanced germination in all tested generations of Sinapis alba L. (white mustard) seeds recommends nCeO2 for seed priming. The investigation of trans-generational effects should be included in any risk assessment addressing the release of nCeO2 (uncoated or coated) to the environment. [ABSTRACT FROM AUTHOR]- Published
- 2023
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20. Surrogate data test for nonlinearity of the rat cerebellar electrocorticogram in the model of brain injury
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Spasić, Slađana
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- 2010
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21. Some details on the method for measuring activity changes of neuronal populations
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Kalauzi Aleksandar, Spasić Slađana Z., and Ćulić Milka
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Biology (General) ,QH301-705.5 - Abstract
Simple, complex action potentials (AP) and interspike recorded background activity (RBA) were detected and extracted from 12 rat cerebellar cortical recordings. For each recording, an averaged simple action potential (SAP) was formed. Fourier amplitude spectra of SAP and RBA were similar in all recordings. For one of the recordings, a series of RBA simulations (SBA) was generated, superimposing random SAPs, varying the superposition frequency (fsup). Average Fourier amplitude, Amp(SBA), was calculated, in order to use Amp(SBA)=f(fsup) as a calibration line for reading fsup of RBA, which is a measure of the population activity. A probability distribution for SAP intensities was derived and a family of calibration lines constructed. As all lines were linear and parallel (slope S) in log-log plots, a population activity change could be calculated as fsup2/fsup1=[Amp2(RBA)/Amp(RBA)]1/S.
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- 2003
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22. Detection of Structural Features in Biological Signals
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Jovanović, Aleksandar, Perović, Aleksandar, Klonowski, Wlodzimierz, Duch, Wlodzisław, Đorđević, Zoran, and Spasić, Slađana
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- 2010
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23. Influence of orange carbon dots on antioxidative activity in maize
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Milenković, Ivana, Zhou, Yiqun, Spasić, Slađana, Leblanc, Roger M., Radotić, Ksenija, Milenković, Ivana, Zhou, Yiqun, Spasić, Slađana, Leblanc, Roger M., and Radotić, Ksenija
- Abstract
Carbon dots (CDs) are spherical organic nanoparticles with a huge potential for application in various biomedical purposes such as sensing, bioimaging, and drug delivery, as well as in water remediation. The discovery of CDs was very popular in the 21th century because they can be used where metal nanoparticles cannot be applied, so they are considered as their green alternative. The main advantages of these nanoparticles are their ease of preparation, solubility in water, high photoluminescence, and biocompatibility. Having all these properties in mind, the main aim of this research was to investigate the effect of orange carbon dots (oCDs), synthesized from citric acid and o-phenylenediamine as precursors, on total antioxidative activity (TAA) in maize as a model plant and agricultural species. We tested antioxidative activity as an indicator of oxidative stress and metabolic disorder in plants. TAA mainly includes the contribution of different non-enzymatic components with antioxidant capacity (vitamins, phenolic acids, sugars, etc.). The maize plants were exposed to three different concentrations (1, 5, and 10 mg L-1) of oCDs nanoparticles via KNOP/2 hydroponic solution during growth under 16 h/8 h photoperiod. After the 2 week-growth, the leaves and roots of plants were separately harvested and collected. The results showed that oCDs did not induce any change in TAA in the leaves, but increased TAA in roots after the treatment of plants with 5 and 10 mg L-1 oCDs. It can be concluded that plant treatment with oCDs’ concentrations ≥ 5 mg L-1 leads to the increase of oxidative stress in roots as a plant organ more exposed to the nanoparticles. This research opens new possibilities in the uses of oCDs in agricultural applications.
- Published
- 2021
24. The long-term effect of carbohydrate-coated nCeO2 treatment on seed protein profile in two herbaceous weedy annuals
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Milenković, Ivana, Mitrović, Aleksandra Lj., Spasić, Slađana, Radotić, Ksenija, Milenković, Ivana, Mitrović, Aleksandra Lj., Spasić, Slađana, and Radotić, Ksenija
- Abstract
Cerium oxide nanoparticles (nCeO2) are attracting continuously growing attention due to their unique properties - their facile transition between Ce3+ and Ce4+ oxidation states. nCeO2 found application in the industry, cosmetics, agriculture, electronics, etc. Their final accumulation in the environment creates new environmental stress factors for living organisms. To improve their solubility, nCeO2 were coated with monosaccharide - glucose and microbial exopolysaccharides - levan and pullulan to obtain glucose-, levan-, and pullulan-coated nCeO2 (G-CeO2, L-CeO2, and P-CeO2). The potential long-term effect of nCeO2 on vegetation was studied in two herbaceous weedy annuals - Sinapis alba and Chenopodium rubrum. It was suggested earlier that the mechanism of maternal environmental effects, that persists for several generations, can act through relative seed protein composition representing an “archive“ of environmental changes experienced by mother plants during their lives. Treatment with nCeO2 of Sinapis alba and Chenopodium rubrum seeds during germination, on total protein content (TPC) and protein profile of seeds produced in two subsequent offspring generations grown in the greenhouse, were investigated. The TPC mainly showed no significant differences, both between treatments and between subsequent generations, in both species. SDS-PAGE electrophoresis showed the presence of 15 protein bands, molecular weight 10 - 140 kDa, in all seed samples of Sinapis alba or Chenopodium rubrum, respectively. We showed that nCeO2 treatment during the very early development of mother plants (germination) has a long-term effect, visible in the difference in width and intensity of seed protein bands of seeds sampled in two subsequent offspring generations.
- Published
- 2021
25. Effect of orange carbon dots on photosynthetic parameters in maize
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Milenković, Ivana, Mitrović, Aleksandra Lj., Spasić, Slađana, Radotić, Ksenija, Milenković, Ivana, Mitrović, Aleksandra Lj., Spasić, Slađana, and Radotić, Ksenija
- Abstract
Plant nanobionics studies nanoparticles application toplants, which improves certain plant functions. Due to many limitations, plants use less photosynthetic capacity thanit is theoretically possible, so an increase in leaf photosynthesis canbe important for increasing crop yield. For this purpose, carbon dots (CDs) as organic, non-toxic nanoparticles with a huge potential for application can be used. They are a green alternative to metal nanoparticles. The main advantages of these nanoparticles are their easy preparation, high water solubility, biocompatibility, and photoluminescence. The main aim of this research was to investigate the effect of orange carbon dots (o-CDs), synthesized from citric acid and o-phenylenediamine as precursors, on photosynthetic efficiency increase in maize (Zea mays L.), as a model plant and agricultural species. We applied o-CDs in three different concentrations (1, 5, and 10 mg/L) by adding to the hydroponic growth solution or foliarly. The photosynthesis parameters (photosynthetic rate, transpiration rate, water use efficiency) and content of photosynthetic pigments (chlorophyll a and b, carotenoids) were recorded. The results showed that the photosynthetic parameters’ values were higher for foliar than for solution application. Amount of 1 mg/L o-CDs applied foliarly and 5 mg/L in solution increased photosynthetic parameters in leaves. The photosynthetic pigments were enhanced after o-CDs treatments. Finding that o-CDs have photosynthesis enhancing potential without harming plants opens new opportunities in their use in agricultural applications, such as increasing plant productivity.
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- 2021
26. Trans-generational effect of carbohydrate-coated cerium oxide nanoparticles in two herbaceous weedy annuals
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Milenković, Ivana, Mitrović, Aleksandra Lj., Spasić, Slađana, Radotić, Ksenija, Milenković, Ivana, Mitrović, Aleksandra Lj., Spasić, Slađana, and Radotić, Ksenija
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Cerium oxide nanoparticles (nCeO2) are nanomaterial widely used in electronics, cosmetics, catalysis, and fuel additives production due to their transition between Ce3+ and Ce4+ oxidation states. Their increasing production (around 10,000 metric tons per year) makes them one of the most produced metal oxide nanoparticles which can lead to unexpected consequences to environmental health and safety. Coating nCeO2 with different polymers is a very popular way to increase their suspension stability, but the data on their effect on cultivated plants are scarce. Environmental effects on morphological and physiological properties of offspring which occur during the development of the mother plant are called maternal environmental effects. Their expression depends on the offspring’s environment, they are expressed throughout the life cycle of the offspring and may persist for several generations. It was suggested that components of the nonenzymatic antioxidant system might participate in the mechanism governing the maternal environmental effects. Total antioxidant activity (TAA) comprises the contribution of different non-enzymatic components with antioxidant capacity. Herbaceous weedy annuals Sinapis alba and Chenopodium rubrum were selected, as a heavy metal hyperaccumulator plant i.e. a species with strong maternal effects, respectively. The effect of uncoated (CeO2) and glucose-, levan-, and pullulan- coated nanoparticles (G-CeO2, L-CeO2, P-CeO2) treatment of Chenopodium rubrum and Sinapis alba seeds during germination, on TAA of seeds produced in two subsequent generations of plants grown in a greenhouse, were investigated. TAA was measured using the ABTS/HRP end point method. Results showed that the effect of nCeO2 treatments was more expressed in Sinapis alba seeds; mainly all nanoparticles treatments during germination of mother plants resulted in the increase in TAA of produced seeds in both monitored generations. In contrast, in Chenopodium rubrum CeO2 treatment r
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- 2021
27. Orange carbon dots change the total phenolic content in maize
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Milenković, Ivana, Zhou, Yiqun, Spasić, Slađana, Leblanc, Roger M., Borisev, Milan, Radotić, Ksenija, Milenković, Ivana, Zhou, Yiqun, Spasić, Slađana, Leblanc, Roger M., Borisev, Milan, and Radotić, Ksenija
- Abstract
INTRODUCTION: Carbon dots (CDs) are considered a green alternative to metal nanoparticles because they can be used where metal nanoparticles cannot be applied. Orange carbon dots (CDs), synthesized from citric acid and o-phenylenediamine as precursors, are organic spherical nanoparticles with a lot of applications in various biomedical purposes such as drug delivery, bioimaging, and sensing. Ease of preparation, high photoluminescence, solubility in water, and biocompatibility are their main advantages. OBJECTIVES: The main aim of this research was to investigate the effect of oCDs on total phenolic activity (TPC) in maize as an agricultural species. TPC reflects the contribution of phenolics as a group of secondary metabolites participating in the regulation of plant growth and in the defense responses. Also, it is one of the main indicators of oxidative stress which can cause a metabolic disorder in plants. METHOD / DESIGN: Three different concentrations (1, 5, and 10 mg L-1) of oCDs nanoparticles were used for the treatment of maize plants via KNOP/2 hydroponic solution during 2 week-growth under 16 h/8 h photoperiod. TPC was analyzed from phenolic extracts obtained from the roots and leaves of plants after foliar and solution treatments. Folin-Ciocalteu’s spectrophotometric procedure was used for the determination of TPC in the samples. RESULTS: The results showed that foliar applications with all concentrations of o-CDs induced decreases of TPC in maize leaves but did not affect these parameters in the roots. In solution treatment, the concentration of 1 mg/L of o-CDs increased TPC in the leaves, but decreased in roots. treatment CONCLUSIONS: The higher efficiency achieved with the lowest o-CD concentration (1 mg/L) in foliar treatment makes this way of application advantageous compared with the solution counterpart.
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- 2021
28. Spatial movement of the Wels catfish (Silurus glanis) in the Danube
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Smederevac-Lalić, Marija, Lenhardt, Mirjana, Spasić, Slađana, Hont, Stefan, Paraschiv, Marian, Iani, Marian I., NICHERSU, IULIAN, Trifanov, Cristian, Nikčević, Miroslav, Klimley, Peter A., Suciu, Radu, Smederevac-Lalić, Marija, Lenhardt, Mirjana, Spasić, Slađana, Hont, Stefan, Paraschiv, Marian, Iani, Marian I., NICHERSU, IULIAN, Trifanov, Cristian, Nikčević, Miroslav, Klimley, Peter A., and Suciu, Radu
- Abstract
Wels catfish (Silurus glanis, Linnaeus, 1758) is one of the most targeted species for recreational and commercial fishing in the Danube River, even though studies of behavior and movement patterns of Wels catfish in the Danube are rare. Wels catfish was caught downstream of Iron Gate II hydropower dam and tagged with an ultrasonic transmitter (Vemco Ltd, V16TP). Nine autonomous receivers (Vemco Ltd, VR 2W) recorded detections of spatial movement downstream of Iron Gate II dam between Serbia and Romania for almost two years, between the years 2015 and 2017. Our telemetry data found that Wels catfish exhibit relatively short movements within a maximum range (≈ 12 km), but as a territorial species most of the time it was recorded by the two receivers, close to the Iron Gate dam and location where it was caught. The longest displacement from the preferable place under Iron Gate II dam was migration to Romanian ship lock and turbines located in the right arm of the Danube River. Location under the river dam is already recognized as a place of aggregation of the fish and thus preference of predatory catfish is strongly connected with food availability. Our data revealed that dam and ship lock blocked further migration of this fish. The last signal received was during the winter 2017, which was a period with extremely low temperature and ice cover on the Danube River. Considering the fact that the ice displaced whole receiver deployment downstream the dam, we might conclude that the tagged catfish disappeared because of ice movement during the winter season. Results can be used for management ensuring habitat requirements and developing of restoration and conservation strategies.
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- 2021
29. Signal transduction in Phycomyces sporangiophores: columella as a novel sensory organelle mediating auxin-modulated growth rate and membrane potential
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Živanović, Branka D., Danilović Luković, Jelena, Korac, Aleksandra, Stanić, Marina, Spasić, Slađana, Galland, Paul, Živanović, Branka D., Danilović Luković, Jelena, Korac, Aleksandra, Stanić, Marina, Spasić, Slađana, and Galland, Paul
- Abstract
The growing zone (GZ) of the unicellular coenocytic sporangiophore of Phycomyces blakesleeanus represents the site of stimulus reception (light, gravity, gas) and stimulus response, i.e., local modulations of the elongation growth, which may result, in dependence of the stimulus direction, in tropic bending. Until now, evidence for a possible participation of the columella in sensory reception is absent. We confirm with light microscopy earlier studies that show that the GZ and the columella are not separated by a membrane or cell wall, but rather form a spatial continuum that allows free exchange of cytoplasm and organelle transport. Evidence is presented that the columella is responsive to external stimuli. Columellae, from which spores and sporangial cell wall had been removed, respond to exogenous auxin with a local depolarization of the membrane potential and an increased growth rate of the GZ. In contrast, auxin applied to the GZ causes a decrease of the growth rate irrespective of the presence or absence of sporangia. The response pattern is specific and relevant for the sensory reception of Phycomyces, because the light-insensitive mutant C148carAmadC, which lacks the RAS-GAP protein MADC, displays abnormal IAA sensitivity and membrane depolarization. We argue that the traditional concept of the GZ as the only stimulus-sensitive zone should be abandoned in favor of a model in which GZ and columella operate as a single entity capable to orchestrate a multitude of stimulus inputs, including auxin, to modulate the membrane potential and elongation growth of the GZ.
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- 2021
30. Tangent algorithm for photogravitropic balance in plants and Phycomyces blakesleeanus: Roles for EHB1 and NPH3 of Arabidopsis thaliana
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Duemmer, Michaela, Spasić, Slađana, Feil, Martin, Michalski, Christian, Forreiter, Christoph, Galland, Paul, Duemmer, Michaela, Spasić, Slađana, Feil, Martin, Michalski, Christian, Forreiter, Christoph, and Galland, Paul
- Abstract
Plant organs that are exposed to continuous unilateral light reach in the steady-state a photogravitropic bending angle that results from the mutual antagonism between the photo- and gravitropic responses. To characterize the interaction between the two tropisms and their quantitative relationship we irradiated seedlings of Arabidopsis thaliana that were inclined at various angles and determined the fluence rates of unilateral blue light required to compensate the gravitropism of the inclined hypocotyls. We found the compensating fluence rates to increase with the tangent of the inclination angles (0? lt ? lt 90? or max. 120?) and decrease with the cotangent (90? lt ? lt 180? or max. 120?of the inclination angles. The tangent dependence became also evident from analysis of previous data obtained with Avena sativa and the phycomycete fungus, Phycomyces blakesleeanus. By using loss-of function mutant lines of Arabidopsis, we identified EHB1 (enhanced bending 1) as an essential element for the generation of the tangent and cotangent relationships. Because EHB1 possesses a C2-domain with two putative calcium binding sites, we propose that the ubiquitous calcium dependence of gravi- and phototropism is in part mediated by Ca2+-bound EHB1. Based on a yeast-two-hybrid analysis we found evidence that EHB1 does physically interact with the ARF-GAP protein AGD12. Both proteins were reported to affect gravi- and phototropism antagonistically. We further showed that only AGD12, but not EHB1, interacts with its corresponding ARF-protein. Evidence is provided that AGD12 is able to form homodimers as well as heterodimers with EHB1. On the basis of these data we present a model for a mechanism of early tropism events, in which Ca2+-activated EHB1 emerges as the central processor-like element that links the gravi- and phototropic transduction chains and that generates in coordination with NPH3 and AGD12 the tangent / cotangent algorithm governing photogravitropic equilibrium.
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- 2021
31. Seasonal changes in depth position and temperature of European catfish (Silurus glanis) tracked by acoustic telemetry in the Danube River
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Lenhardt, Mirjana, Smederevac-Lalić, Marija, Spasić, Slađana, Hont, Stefan, Paraschiv, Marian, Iani, Marian I., Nikčević, Miroslav, Klimley, Peter A., Suciu, Radu, Lenhardt, Mirjana, Smederevac-Lalić, Marija, Spasić, Slađana, Hont, Stefan, Paraschiv, Marian, Iani, Marian I., Nikčević, Miroslav, Klimley, Peter A., and Suciu, Radu
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The giant European catfish, Silurus glanis (total length = 200 cm; total weight approximate to 80 kg) was caught downstream of Iron Gate II hydropower dam (Danube River, 863 rkm) and tagged with an ultrasonic transmitter (V16TP; Vemco Ltd.) equipped with depth and temperature sensors. Changes in catfish diving behavior and temperature exposure were monitored over a period of roughly 2 years. Transmitter detections were recorded by nine autonomous receivers (VR2W, installed in 2015 between Serbia and Romania, as well as near Romanian shiplock and upstream Romanian turbines). The first signals were recorded on April 28, 2015 and the last on February 13, 2017. Altogether 59,355 and 59,175 detections of the catfish depth and water temperature were recorded, respectively. The greatest number of signals were recorded by the two receivers closest to the location where the catfish was caught, 72.3% and 27.1%, while only 0.6% of signals were recorded by other receivers. The mean catfish depth was 8.4 m, while minimum and maximum depths were 1.2 and 16.2 m. Results obtained showed that this catfish exhibited high site fidelity, while changes in depth at certain periods are possibly related to its search for prey and upstream migration during the spawning period. Hydropower dam and shiplock were obstacles on its migration upstream and telemetry studies could ensure habitat requirements and meet the development of restoration and conservation strategies for the fish resources in the future.
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- 2021
32. Photosynthesis Enhancement in Maize via Nontoxic Orange Carbon Dots
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Milenković, Ivana, Borisev, Milan, Zhou, Yiqun, Spasić, Slađana, Leblanc, Roger M., Radotić, Ksenija, Milenković, Ivana, Borisev, Milan, Zhou, Yiqun, Spasić, Slađana, Leblanc, Roger M., and Radotić, Ksenija
- Abstract
The sustained increase in leaf photosynthesis may increase crop yield. Due to many limitations, plants use much less photosynthetic capacity than is theoretically possible. Plant nanobionics investigates nanoparticle application in living plants, which improves certain plant functions. We synthesized and tested nontoxic orange carbon dots (o-CDs) for the photosynthetic efficiency increase in maize (Zea mays L.). We applied o-CDs foliarly or by adding to the growth solution. The photosynthetic parameters and content of photosynthetic pigments were recorded. The total phenolic content (TPC) and total antioxidant activity (TAA) were measured to monitor the plant antioxidant response to o-CDs. The photosynthetic parameters' values were higher for foliar than for solution application. The 1 mg/L o-CDs applied foliarly and 5 mg/L in solution increased photosynthetic parameters in leaves. The o-CDs raised photosynthetic pigments. The TAA and TPC results indicate reduced antioxidant activity in the plant organs more exposed to o-CDs, depending on the way of application.
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- 2021
33. Application of Different Classification Methods to Determine the Developmental Stage of Fish Erythrocytes of the Common Nase (Chondrostoma nasus) and Vimba Bream (Vimba vimba)
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Spasić, Slađana, Subotić, Srđan, Višnjić Jeftić, Željka, Lenhardt, Mirjana, Spasić, Slađana, Subotić, Srđan, Višnjić Jeftić, Željka, and Lenhardt, Mirjana
- Abstract
Fish erythrocytes released from erythropoietic sites are immature. During circulation, they increase their own surface, while the cell body and nuclei begin to become more elliptical and less spherical during maturation. The relative abundance of different developmental stages represents an erythron profile which could be a more sensitive indicator of contamination than classic hematological indices. In this study, we analyzed blood smears of the common nase (Chondrostoma nasus) and vimba bream (Vimba vimba) with the main goal to identify the determinants of the developmental stage of erythrocytes. Based on parameters developmental stages, erythrocytes are categorized into immature, intermediate or mature. In this investigation we have used four classification methods: the Two Step Cluster analysis, the K-Means Cluster analysis, and Neural Networks-Multilayer Perceptron and an Ordinal Regression model. Our findings clearly justify that Multilayers Perceptron and OLR models are appropriate to classify the developmental stage of fish erythrocytes in both species.
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- 2020
34. The effects of Nembutal on the intracerebellar EEG activity revealed by spectral and fractal analysis
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Stojadinović, Gordana, Martać, Ljiljana, Podgorac, Jelena, Spasić, Slađana, Petković, Branka, Sekulic, Slobodan, Kesic, Srdjan, Stojadinović, Gordana, Martać, Ljiljana, Podgorac, Jelena, Spasić, Slađana, Petković, Branka, Sekulic, Slobodan, and Kesic, Srdjan
- Abstract
A detailed analysis of the anesthetic-induced modulation of intracerebellar electrical activity is an important step to understand the functional brain responses to anesthesia. We examined the electrical activity recorded from different cortical layers: molecular layer (ML), Purkinje cell layer (PCL), granular layer (GL) and the white matter (WM) in the vermian part of rat cerebellar lobule V during Nembutal anesthesia using spectral and fractal analysis. Spectral analysis revealed a difference in the mean relative power of delta (0.1-4.0 Hz) and theta (4.1-8.0 Hz) frequencies through the cerebellar layers. Compared to the ML, delta activity increased significantly in the GL, while theta activity decreased in the GL and the WM. Fractal analysis revealed that the mean value of Higuchi's fractal dimension (HFD) increased, starting from the ML to the WM. Theta activity exhibited a negative correlation with the HFD value in the ML. In contrast, the gamma activity showed a positive correlation with the HFD value in the ML and the GL. The combined use of spectral and fractal analyses revealed that Nembutal displays different effects on rat cerebellar electrical activity, which largely depends on the neurochemical and electrophysiological organization of the cerebellar layers.
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- 2020
35. Interaction of Carbohydrate Coated Cerium-Oxide Nanoparticles with Wheat and Pea: Stress Induction Potential and Effect on Development
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Milenković, Ivana, primary, Mitrović, Aleksandra, additional, Algarra, Manuel, additional, Lázaro-Martínez, Juan M., additional, Rodríguez-Castellón, Enrique, additional, Maksimović, Vuk, additional, Spasić, Slađana Z., additional, Beškoski, Vladimir P., additional, and Radotić, Ksenija, additional
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- 2019
- Full Text
- View/download PDF
36. Supplementary data for the article: Milenković, I.; Mitrović, A.; Algarra, M.; Lázaro-Martínez, J. M.; Rodríguez-Castellón, E.; Maksimović, V.; Spasić, S. Z.; Beškoski, V. P.; Radotić, K. Interaction of Carbohydrate Coated Cerium-Oxide Nanoparticles with Wheat and Pea: Stress Induction Potential and Effect on Development. Plants 2019, 8 (11). https://doi.org/10.3390/plants8110478
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Milenković, Ivana, Mitrović, Aleksandra D., Algarra, Manuel, Lázaro-Martínez, Juan M., Rodríguez-Castellón, Enrique, Maksimović, Vuk, Spasić, Slađana Z., Beškoski, Vladimir, Radotić, Ksenija, Milenković, Ivana, Mitrović, Aleksandra D., Algarra, Manuel, Lázaro-Martínez, Juan M., Rodríguez-Castellón, Enrique, Maksimović, Vuk, Spasić, Slađana Z., Beškoski, Vladimir, and Radotić, Ksenija
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- 2019
37. Interaction of carbohydrate coated cerium-oxide nanoparticles with wheat and pea: Stress induction potential and effect on development
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Milenković, Ivana, Mitrović, Aleksandra D., Algarra, Manuel, Lázaro-Martínez, Juan M., Rodríguez-Castellón, Enrique, Maksimović, Vuk, Spasić, Slađana Z., Beškoski, Vladimir, Radotić, Ksenija, Milenković, Ivana, Mitrović, Aleksandra D., Algarra, Manuel, Lázaro-Martínez, Juan M., Rodríguez-Castellón, Enrique, Maksimović, Vuk, Spasić, Slađana Z., Beškoski, Vladimir, and Radotić, Ksenija
- Abstract
Reports about the influence of cerium-oxide nanoparticles (nCeO2) on plants are contradictory due to their positive and negative effects on plants. Surface modification may affect the interaction of nCeO2 with the environment, and hence its availability to plants. In this study, the uncoated and glucose-, levan-, and pullulan-coated nCeO2 were synthesized and characterized. The aim was to determine whether nontoxic carbohydrates alter the effect of nCeO2 on the seed germination, plant growth, and metabolism of wheat and pea. We applied 200 mgL-1 of nCeO2 on plants during germination (Ger treatment) or three week-growth (Gro treatment) in hydroponics. The plant response to nCeO2 was studied by measuring changes in Ce concentration, total antioxidative activity (TAA), total phenolic content (TPC), and phenolic profile. Our results generally revealed higher Ce concentration in plants after the treatment with coated nanoparticles compared to uncoated ones. Considering all obtained results, Ger treatment had a stronger impact on the later stages of plant development than Gro treatment. The Ger treatment had a stronger impact on TPC and plant elongation, whereas Gro treatment affected more TAA and phenolic profile. Among nanoparticles, levan-coated nCeO2 had the strongest and positive impact on tested plants. Wheat showed higher sensitivity to all treatments.
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- 2019
38. Alpha asymmetry index of prefrontal and temporal regions predicts treatment response to repetitive transcranial magnetic stimulation
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Stojadinović, Gordana, Yadollahpour, Ali, Kesić, Srđan Ž., Spasić, Slađana, Stojadinović, Gordana, Yadollahpour, Ali, Kesić, Srđan Ž., and Spasić, Slađana
- Abstract
Aims: Electroencephalography (EEG) measures could be a potential markers for prediction of repetitive transcranial magnetic stimulation (rTMS) outcomes in depression. The aim of this study was to investigate the value of alpha asymmetric index (AAI) in predicting treatment response in two different protocols of rTMS in patients with intractable major depression. Methods: Patients with intractable major depression (n=34) were divided into two treatment groups underwent two different rTMS protocols. The first group received ten sessions 20 Hz rTMS The second group received 10 Hz rTMS . The EEGs were recorded in all subjects pre- and post-intervention using a 19-channel, 10-20 electrodes placement protocol. Hamilton depression rating scale-17 items (HDRS-17) was used to divide the patients into responders and non-responder. The AAI in prefrontal (Fp1-Fp2), frontal (F3-F4 and F7-F8), and temporal (T3-T4) regions were calculated and compared between pre- and post-intervention in each group and between the responder and non-responder groups. Results: In the 20 Hz rTMS group responders, 6 patients responded to the treatment, whereas 10 Hz rTMS showed 8 responders. In the responders of 20 Hz rTMS, the AAI at Fp1-Fp2, F3-F4, and T3-T4significantly decreased after the intervention (P=0.011, P=0.042, and P=0.035). The responders of 10 Hz rTMS showed significant reduction in the AAI at Fp1-Fp2 and T3-T4 regions after intervention (P= 0.023 and P=0.044). Conclusions: It seems AAI at prefrontal and temporal region scould be used for prediction of treatment response, regardless of rTMS protocol.
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- 2019
39. Efekat dejstva elektromagnetnog zračenja bežičnih mreža i mobilnih telefona na zdravlje ljudi
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Spasić, Emilija, Spasić, Slađana, Tomašević, Violeta, Spasić, Emilija, Spasić, Slađana, and Tomašević, Violeta
- Abstract
U radu su predstavljena najnovija istraživanja uticaja elektromagnetnih zra- čenja, prouzrokovanih masovnom primenom bežičnih digitalnih elektronskih uređaja, na zdravlje ljudi i životnu sredinu. Ukazano je na potencijalan uticaj 5G mreža, mobilnih telefona, baznih stanica i poboljšanih bežičnih telefona na učestalost pojave malignih i nemalignih tumora na mozgu, kognitivnih i drugih poremećaja kod ljudi. Ukazano je i na aktivnosti raznih međunarod- nih tela koja pokušavaju da uspostave zakonsku regulativu u ovoj oblasti. S obzirom da se na osnovu do sada dobijenih rezultata ne može sa pouzdanošću dokazati da li nove tehnologije donose više koristi ili štete ljudima i životnoj sredini, došlo je do polarizacije stručne javnosti u svetu po ovim pitanjima. Danas su sa jedne strane industrijski konzorcijumi koji ulažu velika sredstva u razvoj novih tehnologija, a sa druge strane oni koji osporavaju opravdanost ulaganja koja potencijalno ugrožavaju zdravlje ljudi.
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- 2019
40. Effect of static magnetic field on fractal complexity on spontaneous neuronal activity in snail
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Spasić, Slađana, Nikolić, Ljiljana, Mutavdžić, Dragosav, Kartelija, Gordana, Todorović, Dajana, Spasić, Slađana, Nikolić, Ljiljana, Mutavdžić, Dragosav, Kartelija, Gordana, and Todorović, Dajana
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- 2019
41. Single session neurofeedback treatment alters theta/beta-1 and theta/alpha ratios but not sufficient to induce clinical enhancement in attention
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Kesić, Srđan Ž., Yadollahpour, Ali, Riahi, F., Naraghi, M., Stojadinović, Gordana, Spasić, Slađana, Kesić, Srđan Ž., Yadollahpour, Ali, Riahi, F., Naraghi, M., Stojadinović, Gordana, and Spasić, Slađana
- Abstract
Background and Aims: Neurofeedback treatment (NFT) may enhance attention performance in healthy individuals. This study investigated the effects of single session NFT on attention in healthy individuals performing a visual attention task. Methods: This was an open-label single-blinded trial conducted on 14 healthy university students (n=14; mean=23.35±0.58 years) of a major medical university in Iran. The subjects underwent a single session NFT while performing attentional network task (ANT). The NFT protocol was theta suppression/beta-1enhancement applied at Cz for 20 min. Before and immediately after NFT, EEG signals were recorded in subjects while performing ANT. EEGs were recorded using a 19 channel device and 10-20 placement protocol. Results: The single session NFT increased the theta/beta-1 ratio in most of the electrode sites and the increase was statistically significant compared to the pre-intervention in the T6 site (p=0.011). The ratio decreased in just three sites of C3, Fz, and Cz, of them Fz showed a significant reduction (p=0.026). Contrary, the theta/alpha ratio decreased in most of the electrodes where the reductions were statistically significant in P3, P4, Cz, Pz (p<0.05), and C3 (p<0.01). The F7, F8, T3, and T4 showed no significant increased theta/alpha ratio. The central, temporal and occipital regions were involved in the NFT induced changes. Single NFT did not significantly change alerting, executive, or orienting networks of ANT. Conclusions: Theta/beta-1 and theta/alpha ratios can be reliably used to assess NFT induced attention enhancement. However, single NFT did not induce clinical outcomes and repeated sessions seem necessary to modulate alerting, executive, or orienting networks of ANT.
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- 2019
42. Nonlinearity in Living Systems: Theoretical and Practical Perspectives on Metrics of Physiological Signal Complexity
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Spasić, Slađana, Kesić, Srđan Ž., Spasić, Slađana, and Kesić, Srđan Ž.
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- 2019
43. Determination of the development stage of erythrocytes in the common nase (Chondrostoma nasus) using different classification methods.
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Spasić, Slađana, Subotić, Srđan, Višnjić Jeftić, Željka, Lenhardt, Mirjana, Spasić, Slađana, Subotić, Srđan, Višnjić Jeftić, Željka, and Lenhardt, Mirjana
- Abstract
Fish erythrocytes released from erythropoietic sites are immature. During circulation they increase their own surface while the cell body and nuclei begin to become more elliptical and less spherical during maturaration. The relative abundance of different developmental stages represents an erythron profile which could be a more sensitive indicator of contamination than classic hematological indices. In this study, we analyzed blood smears of the Common Nase (Chodrostoma nasus) with the main goal to identify the determinants of the developmental stage of erythrocytes. Based on parameters developmental stages, erythrocytes are categorized into immature, intermediate or mature. In this investigation we have used four classification methods: the Two Step Cluster analysis, the K-Means Cluster analysis and Neural Neworks - Multilayer Perceptron and an Ordinal Regression Model. Our findings clearly justify that Multilayers Perceptron and ORL models are appropriate to classify the developmental stage of fish erythrocytes.
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- 2019
44. Editorial: Nonlinearity in Living Systems: Theoretical and Practical Perspectives on Metrics of Physiological Signal Complexity
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Spasić, Slađana, Kesic, Srdjan, Spasić, Slađana, and Kesic, Srdjan
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- 2019
45. Efekat dejstva elektromagnetnog zračenja bežičnih mreža i mobilnih telefona na zdravlje ljudi
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Spasić, Emilija, primary, Spasić, Slađana Z., additional, and Tomašević, Violeta, additional
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- 2019
- Full Text
- View/download PDF
46. Higučijeva fraktalna dimenzija u analizi fizioloških signala: od matematičke teorije do biološke prakse
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Kesić, Srđan Ž., Spasić, Slađana, Kesić, Srđan Ž., and Spasić, Slađana
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- 2018
47. Phenolic profile of two crop species treated with polysaccharide coated CeO2 nanoparticles
- Author
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Milenković, Ivana, Algarra, Manuel, Spasić, Slađana, Maksimović, Vuk, Mitrović, Aleksandra Lj., Beškoski, Vladimir, Radotić, Ksenija, Milenković, Ivana, Algarra, Manuel, Spasić, Slađana, Maksimović, Vuk, Mitrović, Aleksandra Lj., Beškoski, Vladimir, and Radotić, Ksenija
- Abstract
Cerium oxide nanoparticles (nCeO2) are interesting due to redox property - transition between Ce3+ and Ce4+ ions. Increased usage of nCeO2 may raise its content in the environment, i.e. accumulation in water, air and soil. In many studies nCeO2 was coated with different polymers, but data on the effects of coated nCeO2 on crop species are scarce. In this study, wheat and pea seeds were exposed to 5 day treatment with 200 mg/L uncoated and glucose-, levan- and pullulan-coated nCeO2 during germination. After three weeks of seedlings growth in hydroponics, phenolic profile in shoots was examined. HPLC profiles showed unchanged qualitative composition (type and number of phenolics) in both tested plants. Among 5 identified phenolics, changes in peak areas were observed only in the most dominant phenolic-vicenin 1 in wheat, and in 3 phenolic compounds in pea. Results indicate minor changes of plants’ phenolic metabolism.
- Published
- 2018
48. Effect of polysaccharide coated CeO2 nanoparticles on total phenolic content of two crop species
- Author
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Milenković, Ivana, Spasić, Slađana, Mitrović, Aleksandra Lj., Beškoski, Vladimir, Radotić, Ksenija, Milenković, Ivana, Spasić, Slađana, Mitrović, Aleksandra Lj., Beškoski, Vladimir, and Radotić, Ksenija
- Abstract
Cerium oxide nanoparticles (nCeO2) have been widely investigated because of their unique property - transition between Ce3+ and Ce4+ oxidation states which allows them multiple applications, such as a catalyst, an electrolyte material in fuel cells, for drug delivery, in agriculture (fertilizer, pesticides) etc. Despite these facts, the main restriction of nCeO2 application is their tendency for agglomeration, which led many researchers to coat them with different polymers. But literature data about the impact of coated nanoparticles on plant metabolism are scarce. Also, enhanced nCeO2 application has become the risk for the environment due to their accumulation in soil, air and water. Metal toxicity may lead to overproduction of reactive oxygen species (ROS) causing the abiotic stress and damage of important biological molecules in crop species. In current research, we performed a three week treatment of wheat and pea seedlings in hydroponics with 200 mgL-1 uncoated and glucose-, levan- and pullulan coated nCeO2 (G-CeO2, L-CeO2 and P-CeO2). Our goal was to study the impact of nanoparticles coating on Ce uptake, and on changes in total phenolic content (TPC), as indicator of oxidative stress, in monocotyledonous and dicotyledonous crop species. ICP-OES was used for determination of Ce concentration in shoots of treated crop species. The uptake of Ce was different among treated crop species. Ce uptake was increased after coating in pea, but decreased in wheat. High Ce content detected in wheat, caused the increase in shoot elongation without the effect on TPC. On the other hand, low Ce content measured in pea, had no influence on shoot elongation as well as TPC. Presented results suggest the difference in nCeO2 uptake and their effect on morphological parameters of plant without the impact on phenolic metabolism. Despite these results, further research is necessary.
- Published
- 2018
49. Higuchi’s fractal dimension in plant histology
- Author
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Mitrović, Aleksandra Lj., Janošević, Dušica, Budimir, Snežana, Radotić, Ksenija, Donaldson, Lloyd, Spasić, Slađana, Mitrović, Aleksandra Lj., Janošević, Dušica, Budimir, Snežana, Radotić, Ksenija, Donaldson, Lloyd, and Spasić, Slađana
- Abstract
Fractals are self-similar patterns, from exactly the same to nearly the same, and hence they are common in Nature. Fractal analysis of digital images or signals already has the application in the assessment of properties of tumors, viral infections, blood vessels, neurons, EEG signals, heart rate variability, etc. In different fields of science, especially in botany, application of different fractal methods is necessary to obtain a complete picture of structures or processes. We suggest a new method for 2D Higuchi’s fractal dimension estimation for use in plant analytical microscopy. To present its performance, we used two different sets of digital microscopic images: light microscopy micrographs collected during Tacitus bellus direct shoot organogenesis from leaf explants in vitro, and confocal laser scanning microscopy images of stem cross sections of juvenile Picea omorika trees exposed to static bending stress. Estimated Higuchi’s fractal dimension of presented sets of micrographs enables quantification, separation and alignment of subsequent morphogenic stages of shoot organogenesis on the time scale, i.e. quantitative gradation of structural changes of wood cell properties on a compression severity scale, respectively. Suggested fractal analysis method, combined with statistical analysis, could be used for quantification of structure complexity that characterizes cells and tissues during different growth and developmental processes or stress related structural changes in plants, as well as for the evaluation of the synchronization of those processes. It allows fast computational analysis of micrographs and is independent of the type of microscopy used.
- Published
- 2018
50. Total antioxidant activity in wheat and pea seedlings treated with uncoated and polysaccharide coated CeO2 nanoparticles
- Author
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Milenković, Ivana, Algarra, Manuel, Spasić, Slađana, Mitrović, Aleksandra Lj., Beškoski, Vladimir, Radotić, Ksenija, Milenković, Ivana, Algarra, Manuel, Spasić, Slađana, Mitrović, Aleksandra Lj., Beškoski, Vladimir, and Radotić, Ksenija
- Abstract
CeO2 nanoparticles (nCeO2) are popular because of unique redox property-transition between oxidation states (Ce3+ and Ce4+). Their tendency for agglomeration has led many researchers to coat nCeO2 with different polymers, but little is known about the impact of coated nanoparticles on plant metabolism. Increased nCeO2 application enhance risk for the environment due to their accumulation in soil, air and water. Metal toxicity cause abiotic stress and lead to overproduction of reactive oxygen species (ROS), damaging important biological molecules in plants. In this research, we performed a three week treatment of seedlings of two agricultural plants in hydroponics with 200 mg/L uncoated and glucose-, levan- and pullulan coated nCeO2 (G-CeO2, L-CeO2 and P-CeO2). Our aim was to study the effect of nanoparticles coating on Ce uptake, and on changes in total antioxidant activity (TAA), the indicator of oxidative stress, in monocotyledonous and dicotyledonous crop species. Concentration of Ce in shoots of treated seedlings was determined using ICP-OES. The uptake of Ce differed in the treated plant species. Coating of nCeO2 increased Ce uptake in pea, but decreased in wheat. However, Ce content was 20 fold higher in weat compared to pea plants, regardless of nanoparticles coating. Extremly high Ce content measured in wheat, coincided with the decrease in TAA. On the other hand, low Ce content measured in pea, coinceded with no changes in TAA. Presented results sugest the difference in nCeO2 uptake and its physiological effects between monocotyledonous and dicotyledonous plant species, but further research is necessary.
- Published
- 2018
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