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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.

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.

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.

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.

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.