The springtails (Insecta: Collembola) fauna at different microhabitats of Bečići beach, Montenegro

Collembola fauna has been investigated at different microhabitats near the beach in Bečići, Montenegro. Samples were collected from four locations: Hotel 'Tara', 'Sveti Toma' Church (St. Thomas), Hotel 'Naftagas' and 'Zelena Stena' (Green Rock). Each of the location presented different microhabitat: under the palm tree, cypresses tree, larch tree and white pine tree. Samples were taken in May and September 2015 and results presented as qualitative findings. Total number of 30 Collembola species was identified, classified into six families and 17 genera. Representatives of the family Hypogastruridae and Isotomidae were recorded at all of the studied sites, while representatives of the families: Naenuridae, Onychiuridae, Entomobryidae and Sminthuridae were present on some of locations. The biggest number of species and the highest Collembola population density was found at the Green Stone site, 24 species in total, microhabitat- white pine, and the smallest number of species, 6 on site 'St. Thomas' Church, microhabitat- cypresses trees

A water quality assessment based on benthic diatoms of the timok river basin (Eastern Serbia) under multiple anthropogenic pressures

The study is focused on diatom communities as indicators of the water quality of aquatic ecosystems. The study included watercourses of the Timok River Basin in eastern Serbia. Sampling of algological material and physicochemical measurements were conducted at 30 locations in September 2016. Non-metric multidimensional scaling (NMDS) showed that conductivity had an effect on the spatial variability of the diatom communities. At locations under influence of acid mine drainage along the Borska river, its tributaries and the Timok river, the diversity of benthic diatoms decreased and the abundance of metal tolerant taxa Achnanthidium minutissimum, Nitzschia capitellata and Nitzschia palea increased. Our study revealed that the combined effect of different pollutants significantly impacted on diatom assemblages; diatoms are good bioindicators of multiple pressures; and diatom indices with different types of pollution, may show an unreliable picture of the actual state, therefore, biological and physico-chemical parameters should also be observed when interpreting the results of a solely diatom-based assessment of the ecological condition of freshwaters

Evidence of West Nile virus (WNV) circulation in wild birds and WNV RNA negativity in mosquitoes of the Danube Delta Biosphere Reserve, Romania, 2016

West Nile virus (WNV) is a zoonotic flavivirus whose transmission cycle in nature includes wild birds as amplifying hosts and ornithophilic mosquito vectors. Bridge vectors can transmit WNV to mammal species potentially causing West Nile Fever. Wild bird migration is a mode of WNV introduction into new areas. The Danube Delta Biosphere Reserve (DDBR) is a major stopover of wild birds migrating between Europe and Africa. The aim of this study was to investigate the presence of WNV in the DDBR during the 2016 transmission season in wild birds and mosquitoes. Blood from 68 wild birds (nine different species) trapped at four different locations was analyzed by competitive ELISA and Virus Neutralization Test (VNT), revealing positive results in 8/68 (11.8%) of the wild birds by ELISA of which six samples (three from juvenile birds) were confirmed seropositive by VNT. Mosquitoes (n = 6523, 5 genera) were trapped with CDC Mini Light traps at two locations and in one location resting mosquitoes were caught. The presence of WNV RNA was tested in 134 pools by reverse transcription quantitative PCR (RT-qPCR). None of the pools was positive for WNV-specific RNA. Based on the obtained results, WNV was circulating in the DDBR during 2016

Study of the increased temperature influence on the degradation of photodetectors through ideality factor

Degradation of electrical and optical characteristics of photodetectors in increased temperature conditions is one of the most important limitation factors for their application. Since most of the electrical processes in semiconductor devices depend, to some extent, on temperature, investigations carried out at temperatures higher than room temperature may reveal possible changes in the output characteristics of a device. Temperature dependence of the current-voltage characteristics could suggest a dominant current flow mechanism, and the values of the ideality factor (n) and n(T) dependence could also indicate the presence, location and type of impurities and defects. This is especially important when impurities, localized near dislocations in the material, have energy levels deep in the energy gap. Such localized energy states could act as traps or recombination centers for charge carriers, modulating output current and inducing current noise in photodetector devices. So-called extent current (fluctuations in the output current), indicates the presence of both generation-recombination and burst noise. Magnitudes of these fluctuations are directly connected to the ideality factor and temperature, so monitoring of the n(T) dependence could indicate the changes (degradation) in not only electrical but also in optical properties of the photodiodes

Extraction of parameters from I-V data for nonideal photodetectors: A comparative study

Parameters that characterize semiconductor devices are often determined with difficulty, and their values very frequently depend on the method used for measurements and analysis. The extraction of diode parameters from the obtained I-V measurements could be complicated by their dependence on the voltage and the presence of series resistance. Therefore, an interpretation of the experimental I-V data must be very carefully made. In this paper, some methods for obtaining diode parameters such as saturation current, ideality factor and series resistance are presented. An evaluation of these methods based on their application for the extraction of the relevant parameters of photodiodes is also performed. Some of the methods that produce reliable and reproducible results are evaluated based on the experimentally obtained results, and in the view of the complexity of the used methods and their limitations

Extraction of parameters from I-V data for nonideal photodetectors: A comparative study

Parameters that characterize semiconductor devices are often determined with difficulty, and their values very frequently depend on the method used for measurements and analysis. The extraction of diode parameters from the obtained I-V measurements could be complicated by their dependence on the voltage and the presence of series resistance. Therefore, an interpretation of the experimental I-V data must be very carefully made. In this paper, some methods for obtaining diode parameters such as saturation current, ideality factor and series resistance are presented. An evaluation of these methods based on their application for the extraction of the relevant parameters of photodiodes is also performed. Some of the methods that produce reliable and reproducible results are evaluated based on the experimentally obtained results, and in the view of the complexity of the used methods and their limitations

The innovative method for determining characteristics of over-voltage protection elements

This paper presents an innovative method for efficient characterization of relevant characteristics of non-linear over-voltage protection elements in low-voltage applications. Standard measuring equipment is modified to enable an efficient and repeatable experimental procedure to investigate characteristics of over-voltage diodes and varistors: volt-ampere characteristic, volt-ohm characteristic, coefficient of non-linearity, and finally, the breakdown voltage. Additionally, an innovative aging estimate algorithm was used. Furthermore, the pseudo-empiric method using the "area law" is used to determine an impulse characteristic of a gas filled surge arrester (GFSA). Suggested experimental procedure offers higher measuring accuracy and repeatability because internal temperature of non-linear elements is virtually unchanged during all experiments. All experimental results are treated statistically to prove high repeatability of suggested approach. Comparison of results obtained by suggested experimental method and "classical" approach, shows minimal discrepancies

The First Record of the Freshwater Jellyfish Craspedacusta sowerbii Lankester, 1880 (Hydrozoa) in Kosovo

We report the first record of the alien freshwater jellyfish Craspedacusta sowerbii in Gazivode Lake, northern Kosovo. Gazivode Lake is a drinking-water reservoir, with a depth of up to 107 m, located on the lbar River. The occurrence of the jellyfish was recorded in August and September 2016. The abundance of the population was estimated at 50-60 ind./m(2) of water surface. The medusae were bell-shaped, with a diameter up to 20 mm and well-defined gonads that indicated mature female specimens

The First Record of the Freshwater Jellyfish Craspedacusta sowerbii Lankester, 1880 (Hydrozoa) in Kosovo

We report the first record of the alien freshwater jellyfish Craspedacusta sowerbii in Gazivode Lake, northern Kosovo. Gazivode Lake is a drinking-water reservoir, with a depth of up to 107 m, located on the lbar River. The occurrence of the jellyfish was recorded in August and September 2016. The abundance of the population was estimated at 50-60 ind./m(2) of water surface. The medusae were bell-shaped, with a diameter up to 20 mm and well-defined gonads that indicated mature female specimens

Environmental implication indices from elemental characterisations of collocated topsoil and moss samples

Pollutants, once emitted into the atmosphere, are deposited on the Earth's surface where they further accumulate in both biota and soil. It is therefore a challenge to assess pollutant distributions in different media, and define the various scaling factors to correctly assess each pollutant's environmental implications. In this study, the concentration of potentially toxic elements and their environmental implications were estimated for moss Hypnum cupressiforme Hedw. and the collocated topsoil (0-5 cm) samples, collected from 21 sites across the Province of Kosovo and Metohija (Serbia) during June 2016. The concentrations of Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, U, V, and Zn were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Median Ba, Cd, Cr, Co, Ni, V and maximum As, Cu, Pb, and Zn concentrations in topsoil samples from the study area were higher than prescribed limits in the national and international regulations. Furthermore, we applied and discussed different metrics to assess the pollution level (enrichment factors [EFs], geo-accumulation [I-geo] and pollution load index [PLI]). Different pollution scaling indicates moderate to severe environmental implications (2 lt PLI lt 5; 1 lt I-geo lt 7, 1 lt EFs lt 275) of the potentially toxic elements in the study area. The sampling sites in the northern part of the study area, well-known for their mineral resources, are particularly affected by toxic element pollution, which is likely a consequence of both the exploitation and waste disposal taking place there. More specifically, a comparison of element EFs calculated according to the Earth's crust values with those considering the topsoil background values, points toward a strong influence of (resuspended) soil component in the element enrichment of all environmental samples (i.e., in both the moss an collocated topsoil). However, the EFs of Pb, Cu, Zn, and U in the moss samples were notably higher than those calculated for the collocated topsoil, which could be an indication of a non-local pollution. Finally, both the collocated measurements and multiscale pollution assessment, performed simultaneously, testify to the strong geochemical 'signature' of the studied area