Intestinal content analyses of pumpkinseed Lepomis gibbosus (Linnaeus, 1785) in five small reservoirs – central Serbia

Lepomis gibbosus (pumpkinseed) was first recorded as a non-native fish in Serbia in the 1930s in the Tisza River. The species currently inhabits almost the entire region of the Black Sea basin in Serbia, but has no economic value. The current range of the pumpkinseed covers more than 50% of the total Serbian area and is also naturalised in Serbian waters. The pumpkinseed feeds on bottom fauna, small fish, fish roe and juvenile fish, which together with competition for habitat and spawning sites can have a negative impact on native species. The most common prey of younger specimens is zooplankton, while adult specimens feed on larger organisms such as larvae and pupae of insects, molluscs or crustaceans. The composition of the prey varies seasonally and depends on the composition of the community. The main objective of the study was to analyse the differences in the feeding habits of pumpkinseed in five reservoir. Samples were collected from five reservoirs in central Serbia (<200 asl, Markovačko, Topola, Vlaški Do, Jatagan, Kudreč) using standard electrofishing equipment. All sampled reservoirs had mud substrate, except Jatagan Reservoir, which had gravel substrate. The sampled fish were identified on site based on morphological characteristics using identification keys. The sampled fish were measured using total body length and weight. The total sample consisted of 354 pumpkinseed individuals whose body weight ranged from 3.66–9.52 g and body length from 6.01–8.41 cm. The number of individuals with intestinal content was 282, while the number of individuals with empty stomachs was 72. The following macroinvertebrate taxa were identified during the examination of the gut contents: aquatic insects (Chironomidae, Chironomidae-pupae, Diptera, Ceratopogonidae, Trichoptera, Ephemeroptera, Odonata, Heteroptera, Coleoptera), Gammaridae, Mollusca, Bivalvia, Gastropoda, Nematoda. Undetermined terrestrial insects were also recorded. Most prey were found in the Kudreč Reservoir, and the greatest diversity was in the Topola Reservoir. Jatagan Reservoir had the lowest number of prey items, which may be due to the substrate type. The high number of aquatic insect taxa could be explained by the small surface area of the reservoir and the presence of aquatic vegetation

Modulation of c-Jun N-terminal kinase signaling and specific glucocorticoid receptor phosphorylation in the treatment of major depression

Glucocorticoid resistance is a common finding in major depressive disorder. Increased glucocorticoid receptor (GR) phosphorylation at serine 226 is associated with increased glucocorticoid resistance. Previously we have demonstrated that depressed patients exhibit higher levels of GR phosphorylated at serine 226 compared to healthy controls. The enzyme that is involved in this specific GR phosphorylation is c-Jun N-terminal kinase (JNK). We propose that modulation of glucocorticoid phosphorylation at serine 226, by targeting JNK signaling pathway, could be a potential strategy for antidepressant treatment. We base this assumption on the results of previous research that examined GR phosphorylation and JNK signaling in animal models and human studies. We also discuss the potential challenges in targeting JNK signaling pathway in depression. (C) 2015 Elsevier Ltd. All rights reserved

PROCENA DIVERZITETA VRSTA RIBA I KVALITETA VODE U PET AKUMULACIJA U SRBIJI ZASNOVANA NA ŠENONOVOM INDEKSU DIVERZITETA

Značaj riba kao bioindikatora kvaliteta vode potvrđen je brojnim istraživanjima, a zasniva se na njihovoj dugovečnosti, mobilnosti, pripadnosti različitim funkcionalnim trofičkim grupama i osetljivosti na širok spektar antropogenih stresora. Cilj ovog istraživanja bilo je poređenje diverziteta vrsta riba u akumulacijama Garaši, Perućac, Zaovine, Ovčar i Međuvršje na osnovu Šenonovog indeksa diverziteta (H), kao i procena kvaliteta vode na osnovu poređenja vrednosti ovog indeksa sa rezultatima merenja fizičkih i hemijskih parametara vode. Uzorkovanje riba je vršeno mrežama (20-50 m dužine, 1.5-2 m visine i 28-100 mm promera okca) tokom leta 2017. godine. Ukupno je uzorkovano 795 jedinki riba koje pripadaju 21 vrsti. Multiparametarska sonda YSI 6600 V2-2 korišćena je za prikupljanje podataka o fizičkim, hemijskim i biološkim karakteristikama ispitivanih akumulacija. Praćene su vrednosti pH, rastvorenog kiseonika (DO) i hlorofila a. Prema vrednostima Šenonovog indeksa diverziteta za pomenute akumulacije, diverzitet naselja riba pokazao je sledeći trend: Perućac (H = 1.81) > Ovčar (H = 1.69) > Garaši (H = 1.52) > Zaovine (H = 1.45) > Međuvršje (H = 1.27). A kumulacije G araši, Perućac i O včar i male su k valitet vode koji spada u II-III klasu, dok je lošiji kvalitet (III-IV klasa) zabeležen za akumulacije Zaovine i Međuvršje. Procena kvaliteta vode na osnovu Šenonovog indeksa diverziteta poklapa se sa procenom kvaliteta vode baziranom na merenju pH vrednosti, rastvorenog kiseonika (DO) i hlorofila a, osim za akumulaciju Zaovine. Rezultati istraživanja sugerišu da kombinovanje Šenonovog indeksa diverziteta i merenja fizičkih i hemijskih parametara može pružiti pouzdanu procenu kvaliteta vode u istraživanim akumulacijama

Kinematics of gait:new method for angle estimation based on accelerometers

A new method for estimation of angles of leg segments and joints, which uses accelerometer arrays attached to body segments, is described. An array consists of two accelerometers mounted on a rigid rod. The absolute angle of each body segment was determined by band pass filtering of the differences between signals from parallel axes from two accelerometers mounted on the same rod. Joint angles were evaluated by subtracting absolute angles of the neighboring segments. This method eliminates the need for double integration as well as the drift typical for double integration. The efficiency of the algorithm is illustrated by experimental results involving healthy subjects who walked on a treadmill at various speeds, ranging between 0.15 m/s and 2.0 m/s. The validation was performed by comparing the estimated joint angles with the joint angles measured with flexible goniometers. The discrepancies were assessed by the differences between the two sets of data (obtained to be below 6 degrees) and by the Pearson correlation coefficient (greater than 0.97 for the knee angle and greater than 0.85 for the ankle angle)

Trichoderma spp. From pine bark and pine bark extracts: Potent biocontrol agents against botryosphaeriaceae

Pinus sylvestris bark represents a rich source of active compounds with antifungal, antibacterial, and antioxidant properties. The current study aimed to evaluate the antifungal potential of P. sylvestris bark against Botryosphaeria dothidea, Dothiorella sarmentorum, and Neofusicoccum parvum (Botryosphaeriaceae) through its chemical (water extracts) and biological (Trichoderma spp. isolated from the bark) components. The water bark extracts were prepared at two temperatures (80 and 120◦C) and pH regimes (7 and 9). The presence of bark extracts (30%) caused inhibition of mycelial growth of B. dothidea and D. sarmentorum for 39 to 44% and 53 to 60%, respectively. Moreover, we studied the antagonistic effect of three Trichoderma isolates originating from the pine bark. Trichoderma spp. reduced growth of B. dothidea by 67%–85%, D. sarmentorum by 63%–75% and N. parvum by 55%–62%. Microscopic examination confirmed typical mycoparasitism manifestations (coiling, parallel growth, hook-like structures). The isolates produced cellulase, β-glucosidase and N-acetyl-β-glucosaminidase. The volatile blend detected the emission of several volatile compounds with antimicrobial activity, including nonanoic acid, cubenene, cis-α-bergamotene, hexanedioic acid, and verticillol. The present study confirmed in vitro potential of P. sylvestris bark extracts and Trichoderma spp. against the Botryosphaeriaceae. The study is an important step towards the use of environmentally friendly methods of Botryosphaeriaceae disease control

Indicators of unsustainable fishery in the Middle Danube

Fishery in the Danube River basin has been characterised over the past century by increasing fishing levels, illegal fishing practices and poor regulations. However, there is a remarkable lack of available information on the actual status of fish stocks, as well as on the trends and sustainability of fisheries, which poses a problem for the development of adequate policy and management measures. In this study, we assessed the trends in the commercial fishery in the Middle Danube in Serbia during 1969-1989 and 2006-2010 by evaluating the temporal changes in life history-related indicators that might point out unsustainable fishing pressures. Moreover, we present the approach of using the catch-weighted mean egg-per-recruit (EPR) index as a proxy for the overall resilience of fish stocks to fishing. Results indicated a marked shift towards smaller fish that mature earlier and have a shorter lifespan. Landings also shifted towards species at lower trophic levels, with a mean trophic level decline at a rate of approximately 0.16 per decade. Results indicated likely presence of the fishing through the food web' phenomenon. At the same time, catch-weighted community mean of the 20% EPR threshold ratio (EPR20%) increased by 4.2%, indicating the increase of the overall resilience to fishing of the exploited species. Obtained results indicated the importance of using such metrics for the assessments of trends in fishery. The approach and results presented here could be of interest for the scientific community and stakeholders involved in fishery management