BIOREpository (Faculty of Biology, University of Belgrade)
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Geraniol in vitro and geraniol-based emulsion ex vivo potential against four-species Streptococcus spp. biofilm relevant for dentistry
No full textObjective: Concerning the importance of developing novel oral hygiene adjuncts, the aim of this study was to screen antibacterial/antibiofilm potential of geraniol and to formulate its stable nanoemulsion(s), capable to combat caries-related streptococcal multispecies biofilm. Materials and methods: Antibacterial and antibiofilm activities of geraniol were estimated in microdilution and crystal-violet assays, respectively. Five geraniol-based emulsions with Tween80 were formulated and screened for particle size diameter and stability, using dynamic light scattering measurements. The selected emulsion was characterized by TEM, and ex vivo screened against four-species biofilm settled on enamel discs, by determination of CFU. Results: The antibacterial potential of geraniol was moderate (MICs 0.55–1.11 mg/mL against S. mutans, S. sanguinis, S. gordonii and S. mutans). Geraniol significantly prevented biofilm formation and disrupted pre-formed ones (inhibition ranges against all isolates were 12.00–93.66 %, and 55.54–100 %, respectively). Emulsions (Eger:tween80) E200:200, E500:500, and E800:800 were stable and nanosized (Zavg˂200 nm). TEM of E800:800 revealed black spherical spots surrounded by grey stain. Ex vivo four-species streptococcal biofilm disruption assay showed notable inhibitory potential of E800:800 (ΔLogCFU 1.77 and 3.89, solely and in combination with chlorhexidine, respectively). Conclusion: E800:800 showed ex vivo potential against streptococcal multispecies biofilm, especially in combination with chlorhexidine. Clinical Significance: Presented results encourage further research of the examined nanoemulsions as potential part of daily oral hygiene, aiming to provide prevention of caries development.M21a5.60011982722
The effect of increasing Li concentrations on physiological stress parameters in Miscanthus × giganteus plants
No full textBook of abstracts, P.0374M3
Habitat Richness and Seasonal Occurrence of Large Branchiopods (Crustacea: Branchiopoda) in the Areas of the Ramsar Site “Bardača Wetland” and the Donja Dolina in Bosnia and Herzegovina
No full textMulti-year studies were carried out in the "Bardača Wetland" and Donja Dolina areas in northern Bosnia and Herzegovina. Nine taxa of large branchiopods were found at the surveyed sites. All registered taxa show a continuous seasonal distribution with a partial overlap of temporal occurrence. Based on the environmental characteristics of the water body, the cluster analysis separated two groups of habitats: 1) the zone of flooded pastures around the Sava River and 2) small ponds of different depths, which mainly occur in the pastures outside the floodplain. Within each cluster, several groups of habitats were distinguished. The results of the Spearman correlation analysis showed no correlation between the number of species and the individual environmental parameters. A clear seasonal distribution of taxa can be observed: three taxa occur in late winter and early spring, one in mid-spring and five were reported only in late spring. Triops cancriformis was recorded for the first time in Bosnia and Herzegovina. This study suggests that an plentifulness of environmental factors and specific seasonal fluctuations favour species richness rather than single environmental parameters in individual habitats. Due to the study area's high natural and cultural-historical value, "Bardača" and Donja Dolina should be continuously monitored and protected.M230.58796Supplement 2
Parental care in Stenotaenia rhodopensis (Kaczmarek, 1970) (Chilopoda: Geophilomorpha)
No full textThe females of the geophilomorph centipede Stenotaenia rhodopensis (Kaczmarek, 1970) guard the eggs and young by wrapping their bodies around the brood so that the ventral side is exposed to the outside. This observation confirms the basal division of the Geophilomorpha into Placodesmata (comprising only the family Mecistocephalidae) and Adesmata, which corresponds to the anatomical differences between these groups, especially with regard to the absence or presence of ventral pores, the openings of the ventral glands. We have provided comparative data for some external morphological characters between young and their mothers to clarify changes in taxonomic characters during early post-embryonic development. In addition, we have explained some of the key terms used in the study of the evolution of parental care and identified ecological factors such as harsh environments and predation pressure as possible evolutionary drivers of parental care in centipedes.M230.732833433
COMPARISON OF ADARB1 AND TPH2 VARIANTS BETWEEN SLOVENIAN AND SERBIAN CASES ON THE CONTINUUM OF SUICIDAL BEHAVIOR
No full textBook of abstracts: page 122M6
Brown and red shades in the riverbed of the Nera River (Serbia)-Update on the distribution and ecology of the association Hildenbrandio rivularis-Heribaudielletum fluviatilis Fritsch 1929 corr. Täuscher 2020 in Southeastern Europe
No full textHeribaudiella fluviatilis (Areschoug) Svedelius is one of the rare representatives of freshwater brown algae, and its range is restricted to the Northern Hemisphere. Hildenbrandia rivularis (Liebmann) J. Agardh is still one of the endangered red algae species in Europe, although its indicator value and distribution have recently been questioned. The association Hildenbrandio rivularis-Heribaudielletum fluviatilis Fritsch 1929 corr. Täuscher 2020 occurs mainly in Northern and Central Europe, while its occurrence and ecology in Southern Europe are poorly researched. The lower reaches of the Nera River near the small town of Bela Crkva, Serbia, were searched for macroalgae in August 2021 and June 2022, when stones with macroalgal crusts were collected. Environmental parameters were measured in situ and water samples were collected for further analysis. A sample of the epilithic diatom community was collected to calculate diatom indices. We present the occurrence of the association Hildenbrandio rivularis-Heribaudielletum fluviatilis in the lower course of the Nera River in Serbia, relating the ecology of the species and habitat to previous findings from the Southeast European region. We discuss potential indicator values of macroalgae associations, rather than of a single species.M230.921822653
Evaluation of hsa-mir-675-5p expression and its diagnostic and prognostic relevance in oral cancer
No full textIntroduction: Oral cancer is the most common subtype of cancer in the head and neck region, with an increasing incidence worldwide. Unfortunately, no specific biomarkers are used in everyday clinical practice. Small non-coding RNA molecules, microRNA (miRNA), are considered sensitive biomarkers for early diagnosis as well as prognosis in patients with oral cancer. Especially, microRNA derived from the H19 locus are poorly investigated for their potential role in oral cancer. Aim: The aim of this study was to evaluate expression of hsa-miR675-5p in tumor and non-tumor tissues of oral cancer patients and to associate it with pathohistological features. Material and Methods: The study group consisted of 35 patients with oral cancer. Tumor and surrounding non-tumor tissues were taken from each patient. Relative expression was measured using the quantitative reverse transcription - real time PCR method. Results: The relative expression of hsa-miR-675-5p was lower in oral cancer tumor than in non-tumor tissue suggesting its tumor suppressive role. hsa-miR-675-5p has diagnostic potential for sensitive distinction of tumor and non-tumor tissues in oral cancer patients. There was no difference in overall survival rates between patients with low and high hsa-miR-675-5pexpression, confirming that hsa-miR-675-5p cannot be used as a prognostic biomarker in patients with oral cancer. Conclusion: hsa-miR-675-5p can be considered as a potential diagnostic but not a prognostic molecular biomarker in oral cancer.M539910557
Synergistic effects of musking and autohaemorrhaging on the duration of death feigning in dice snakes (Natrix tessellata)
No full textPredation exerts a significant selection pressure on prey, shaping a multitude of traits that serve as antipredator defences. In turn, natural selection could favour combinations of antipredator defences with synergistic effects that enhance prey survival. An especially interesting antipredator defence is death feigning (DF), present in a wide variety of taxa and usually characterized by the prey lying motionless often along with defaecation, musking and autohaemorrhaging (AH). All these aspects of the DF display should work in conjunction with one another, intensifying the overall effect of the display and in turn facilitating quicker escape. To confirm this hypothesis, we tested 263 dice snakes (Natrix tessellata) directly in the field. We noted the occurrence of smearing faeces, musk and AH, and we measured the duration of DF, expecting to see a negative association between the occurrence of these behaviours and the duration of DF. Our results affirm our hypothesis: dice snakes that smeared themselves in musk and faeces prior to DF and had AH during DF spent significantly less time in DF. Our results highlight the functional integration of antipredator behaviours across different phases of predator-prey interactions, emphasizing the need for future research to prioritize studying the sequential display of behaviours.M213.42024005820
Automated identification of aquatic insects: A case study using deep learning and computer vision techniques
No full textDeep learning techniques have recently found application in biodiversity research. Mayflies (Ephemeroptera), stoneflies (Plecoptera) and caddisflies (Trichoptera), often abbreviated as EPT, are frequently used for freshwater biomonitoring due to their large numbers and sensitivity to environmental changes. However, the morphological identification of EPT species is a challenging but fundamental task. Morphological identification of these freshwater insects is therefore not only extremely time-consuming and costly, but also often leads to misjudgments or generates datasets with low taxonomic resolution. Here, we investigated the application of deep learning to increase the efficiency and taxonomic resolution of biomonitoring programs. Our database contains 90 EPT taxa (genus or species level), with the number of images per category ranging from 21 to 300 (16,650 in total). Upon completion of training, a CNN (Convolutional Neural Network) model was created, capable of automatically classifying these taxa into their appropriate taxonomic categories with an accuracy of 98.7 %. Our model achieved a perfect classification rate of 100 % for 68 of the taxa in our dataset. We achieved noteworthy classification accuracy with morphologically closely related taxa within the training data (e.g., species of the genus Baetis, Hydropsyche, Perla). Gradient-weighted Class Activation Mapping (Grad-CAM) visualized the morphological features responsible for the classification of the treated species in the CNN models. Within Ephemeroptera, the head was the most important feature, while the thorax and abdomen were equally important for the classification of Plecoptera taxa. For the order Trichoptera, the head and thorax were almost equally important. Our database is recognized as the most extensive aquatic insect database, notably distinguished by its wealth of included categories (taxa). Our approach can help solve long-standing challenges in biodiversity research and address pressing issues in monitoring programs by saving time in sample identification.M21a9.817287793