Ecological status assessment of the Samokovska river: 2018 case study

The Samokovska River, as the most important watercourse of the Kopaonik National Park, has been poorly investigated from algological and water quality aspects. This river is not covered by the monitoring program of the Serbian Environmental Protection Agency routine. Our research performed in October 2018 aimed to present an algal diversity, ecological status assessment, and negative anthropogenic impacts threatening this river. For ecological status assessment purposes, the diatom indices phytobenthos and physico-chemical parameters of water were used. The typology and the problem of reliable assessing of the ecological status were also discussed on the example of the Samokovska River.

Health risk assessment of natural and artificial radionuclides in medicinal plants

In the present work, we determined activity concentrations of ten Medicinal herbs using gamma spectrometry. The radioactivity concentration of 226 Ra, 232 Th, 40 K and 137 Cs were 2.82, 0.63, 984.32, 0.28 Bq/kg, respectively. These doses are not hazardous to the general public's health. The mean values of radium equivalent activity (Raeq), absorbed dose rates (D), annual effective dose (De) and external hazard index (Hex) are 79.51 Bq/kg, 42.73 nGy-1 , 52.40 µSv and 0.21, respectively. Medicinal plants used to make tea do not contain a concentration of tested radionuclides that would cause negative consequences to one's health.

Flavonoids from aerial part of Algerian Ajuga iva (L.) schreb.: The HPLC-UV analysis and Antioxidant capacity

The study deals with the evaluation of the antioxidant capacity of extracts from the aerial part of Algerian Ajuga iva. Extraction of flavonoids was carried out by 85% of methanol, then the crude extract was successively separated with ethyl acetate, butanol, and water. The in vitro antioxidant activity was assessed by 1,1-diphenyl-2-picrylhydrazyl, reducing power, and thiobarbituric acid reacting substances assays. Extracts are subject to HPLC-UV analysis. The average total phenol contents of extracts vary between 3.87 ± 0.17 and 149.74 ± 3.94 (gallic acid equivalent per gram of dry extract). Furthermore, tested extracts exhibited a broad range of flavonoid contents varying from 1.54 ± 0.09 to 41.18 ± 1.03 (catechin equivalent per gram of dry extract). Butanol and ethyl acetate fractions displayed the highest antioxidant activity. A good correlation between the phenolic and flavonoid contents and the antioxidant activity was observed. Rutin, caffeic acid, quercetin, p-coumaric acid, luteolin, and cinnamic acid were present in the extracts. The plant could be a potential source of antioxidant agents.

Liparus (Liparus) glabrirostris Küst. and Hylobius (Callirus) abietis (L.) (Coleoptera: Curculionidae) first records for Serbia

This paper presents a survey of data on two weevil species not recorded for the fauna of Serbia till now. Despite their large size, Liparus (Liparus) glabrirostris Küster, 1849 and Hylobius (Callirus) abietis (Linnaeus, 1758) have not been recorded for Serbia in the newest Palaearctic weevil catalogue (Alonso-Zarazaga et al., 2017) or in the Fauna Europaea (Alonso-Zarazaga et al., 2013, https://fauna-eu.org/). In this paper L. glabrirostris, found in a single locality on Mt Goč, is registered as the third representative of the genus Liparus Olivier, 1807 in Serbia. Hylobius abietis is a serious, widely distributed conifer pest, but was not faunistically registered for Serbia till now. Some ecological data and distribution maps with Serbian locations are given for both species.

Affinity of class I and class III peroxidases for H2O2 in pepper leaves of different maturity

Paper deals with activities of Class III peroxidases (POX, EC 1.11.1.7) and Class I peroxidases (ascorbate peroxidase, APX, EC 1.11.1.11) as well as the Km of these enzymes for hydrogen peroxide (H2O2) in the pepper leaves of different maturity. The obtained results suggest that the youngest pepper leaves compared to more mature ones have different strategies for H2O2 removal. There was an increase in APX activity with leaf maturity, while POX activity had the opposite trend, and its lowest activity was observed in the oldest leaves. The accumulation of reducing substrates i.e., ascorbate and total phenols was in positive correlation with corresponding enzymes following leaf maturity. The comparison of POX and APX affinity for H2O2 in pepper leaves of different maturity and their relationship between these enzymes' activities were showed.

Seasonal dynamics of epilithic diatom community from the Vrla River (Southeastern Serbia)

Seasonal analysis of epilithic diatom community from the Vrla River was performed in four seasons a year (six times) at six sampling sites. Between the second (VR2) and the third sampling site (VR3) was located a trout fish farm. The highest number of diatom taxa was recorded in spring (149) and the lowest in autumn (93). The number of taxa that were found to be dominant during all four seasons was twenty-four. The relationship between 45 the best-fitted diatom taxa, which showed conspicuous seasonal dynamics, and seasons in which these taxa were recorded was illustrated using canonical correspondence analysis (CCA). The large number of taxa was identified in all four seasons or in winter period only. Few taxa were present only in spring and summer.

New records and remarks on earthworms of the Vojvodina Province (Oligochaeta: Lumbricidae, Criodrilidae)

The aim of this paper is to present the results of the recent collecting earthworms, with new localities and new habitats in Vojvodina Province. The sporadic field investigation was carried out during 2013-2020. In this paper we report new records of Criodrilus lacuum Hoffmeister, 1845 (family Criodrilidae) proved to be new species for the fauna of Vojvodina Province. Also, information on the taxonomic status of individual species was provided. Fifteen earthworm species and subspecies from family Lumbricidae have been registered. Six taxa were found to be synonymous with nominal species, so that the number decreases to 31 species, from 10 genera. Our data demonstrate clearly that the earthworm fauna of the Vojvodina Province is relatively poor, monotonous and that the impact of intensification of agricultural practices effect on loss of soil biodiversity.

Six new hoverfly species (Diptera: Syrphidae) in the fauna of Serbia

During a survey conducted from 2018 to 2021, six hoverfly species were registered on the territory of Serbia for the first time: Chalcosyrphus pannonicus (Oldenberg, 1916), Chrysogaster coemiteriorum (Linnaeus, 1758), Eristalinus taeniops (Wiedemann, 1818), Melanogaster parumplicata (Loew, 1840), Merodon testaceus Sack, 1913 and Psilota atra (Fallén, 1817). Data about new records are presented.

Endolithic phototrophs: Examples from cave-like environments

Endoliths are more frequently found in extremely harsh environments, but they can inhabit mesic climate and subterranean habitats as well. Whether they are adapted to life inside rocks or do they seek refuge in this way, remains largely unknown for caves and pits. Consequently, subterranean habitats in limestone areas, were explored: three caves in Serbia (Cerjanska, Petnička and Potpeć) and one pit in Croatia (Keranova Golubinka). Sampling of rock substratum containing endoliths was performed at various distances from the entrance, at sites characterized by a lower level of light intensity. Phototrophs were separated from the rock matrix using 10% hydrochloric acid and analyzed using light microscopy. In general, low diversity of endoliths was observed, but representatives from Cyanobacteria, Chlorophyta and Xanthophyta were found. Cyanobacteria, more precisely coccoid forms (genera Aphanocapsa, Chroococcidiopsis, Gloeocapsa, Gloeocapsopsis, Synechococcus), were dominant. The most interesting cyanobacterial taxon, Leptolyngbya-like taxon, representing a true endolith (euendolith), was found in the Petnička Cave. This taxon and its relation to the substratum, as well as chasmoendolithic community from the Keranova Golubinka Pit, were observed using Scanning electron microscopy (SEM). It was observed that chasmoendoliths inhabit already existing surface rock cracks and fissures, while a true endolith actively bores into the substratum. Non-metric multidimensional scaling (NMDS) was performed to observe the similarity between the sampling sites. Endoliths can grow inside the rocks, making them very successful biodeteriogens, which is not a desirable trait for caves and pits that are characterized by various attractive geomorphological features that need to be preserved. Thus, considering these habitats, more attention should be paid to the endolith community in the future.

The effect of magnetic field on the tunneling yield of ammonia molecules

We analyzed the influence of magnetic component of the laser field on the tunneling yield, in a strong near-relativistic field for a squared hyperbolic secant pulse distribution. The obtained results indicate that the inclusion of the magnetic component is necessary in the observed regime.