Biološke i ekološke karakteristike crnke umbra krameri kao osnov za in-situ i ex-situ zaštitu

The analysis of ecological characteristics and morphological-genetic differentiation of populations of the European mudminnow (Umbra krameri Walbaum, 1792) from the localities Lugomir and Bakreni Batar in Serbia and the locality Gromiželj in Bosnia and Herzegovina provides a basis for future activities related to in situ and ex situ conservation of one of the most endangered species in the region. Physical and chemical habitat parameters, aquatic plant and fish species composition, as well as invertebrate assemblages from mud and submerged vegetation at all investigated localities are consistent with the literature data which indicates that European mudminnow lives in typical habitats within its range. Population structure was analysed with regard to measured body lengths and weights, sex ratio and the age of the sampled individuals. The results show that the mean lengths and weights of the most frequent age classes (1+ and 2+) are rather uniform at all investigated localities. Younger (0+) and older (3+ and 4+) individuals were recorded in Gromiželj; males outnumber females in samples from Lugomir and Bakreni Batar, while females outnumber males in samples from Gromiželj. Individuals from Gromiželj show the highest absolute and relative growth. The growth of this species varies and depends on several factors, such as physical and chemical environmental parameters, food availability, population density, presence of predators, etc. Qualitative and quantitative composition of European mudminnow diet was determined on the basis of its gastrointestinal contents. The obtained results indicate that the European mudminnow is a zoophagous species and an opportunistic predator. The morphological variability (body size and shape) was analyzed using the methods of geometric morphometrics, while the genetic diversity of the analyzed populations was determined by applying the molecular-genetic methods (microsatellites and mitochondrial DNA). These analyses indicate high level of compatibility between the morphological variability and the genetic diversity. Namely, the Danube River population from Lugomir differs from the Sava River populations from Bakreni Batar and Gromiželj, the latter two having a significantly higher level of similarities and relatedness. All obtained results are extremely important for implementing the adequate measures of active protection, conservation, and improvement of recent populations, most notably repopulation, reintroduction, and aquaculture of the European mudminnow in ex situ conditions and at controlled natural spawning sites within their habitats.Na osnovu analize ekoloških karakteristika i morfološko-genetičke diferencijacije populacija crnke (Umbra krameri Walbaum, 1792) sa lokaliteta Lugomir i Bakreni Batar u Srbiji kao i sa lokaliteta Gromiželj u Bosni i Hercegovini, dat je osnov za buduće aktivnosti na in-situ i ex-situ zaštiti jedne od najugroženijih vrsta riba na ovim prostorima. Analiza fizičko-hemijskih parametara vode i kvalitativnog sastava zajednice biljaka, riba, akvatičnih beskičmenjaka iz mulja i submerzne vegetacije pokazala je da su na svim istraživanim lokalitetima rezultati u skladu sa literaturnim podacima koji ukazuju na to da crnka naseljava tipična staništa u okviru svog areala. U odnosu na dužinu i težinu, pol i uzrast uzorkovanih jedinki, analizirana je struktura populacija, koja je pokazala da su na svim istraživanim lokalitetima srednje vrednosti dužinskih i težinskih parametara kod najfrekventnijih uzrasnih klasa (1+ i 2+) prilično ujednačene, da su na Gromiželju evidentirane i mlađe (0+) i starije (3+ i 4+) jedinke, kao i da mužjaci dominiraju u uzorcima iz Lugomira i Bakrenog Batara, a ženke u uzorku iz Gromiželja. Analizom dužinskog i težinskog rasta, najveći apsolutni i relativni priraštaj ustanovljen je kod jedinki sa lokaliteta Gromiželj, a konstatovano je i da rast crnke varira i zavisi od više faktora, kao što su fizičko-hemijski parametri sredine, dostupnost hrane, gustina populacija, prisutni predatori itd. Na osnovu želudačno-crevnog sadržaja utvrđen je kvalitativno-kvantitativni sastav ishrane crnke, koji ukazuje na to da crnka predstavlja zoofagnu vrstu i oportunističkog predatora. Metodama geometrijske morfometrije analizirana je varijabilnost spoljašnje morfologije, odnosno varijabilnost veličine i oblika tela istraživanih populacija, a upotrebom molekularno-genetičkih metoda (mikrosateliti i mitohondrijalna DNK), utvrđena je i genetička raznovrsnost analiziranih populacija. Uz visok stepen podudarnosti dobijenih rezultata korišćenjem navedenih metoda, utvrđeno je jasno razdvajanje dunavske populacije sa lokaliteta Lugomir u odnosu na savske populacije sa lokaliteta Bakreni Batar i Gromiželj, koje pokazuju znatno veći stepen međusobne sličnosti i srodnosti. Svi dobijeni rezultati ovih istraživanja od izuzetne su važnosti za preduzimanje odgovarajućih mera aktivne zaštite, očuvanja i unapređenja stanja recentnih populacija, od kojih su najznačajniji repopulacija, reintrodukcija i akvakultura crnke u ex situ uslovima i u kontrolisanim prirodnim plodištima na samim staništima

On the role of peripheral sensory and gut mu opioid receptors: Peripheral analgesia and tolerance

There is growing evidence on the role of peripheral \ub5-opioid receptors (MORs) in analgesia and analgesic tolerance. Opioid analgesics are the mainstay in the management of moderate to severe pain, and their efficacy in the alleviation of pain is well recognized. Unfortunately, chronic treatment with opioid analgesics induces central analgesic tolerance, thus limiting their clinical usefulness. Numerous molecular mechanisms, including receptor desensitization, G-protein decoupling, \u3b2-arrestin recruitment, and alterations in the expression of peripheral MORs and microbiota have been postulated to contribute to the development of opioid analgesic tolerance. However, these studies are largely focused on central opioid analgesia and tolerance. Accumulated literature supports that peripheral MORs mediate analgesia, but controversial results on the development of peripheral opioid receptors-mediated analgesic tolerance are reported. In this review, we offer evidence on the consequence of the activation of peripheral MORs in analgesia and analgesic tolerance, as well as approaches that enhance analgesic efficacy and decrease the development of tolerance to opioids at the peripheral sites. We have also addressed the advantages and drawbacks of the activation of peripheral MORs on the sensory neurons and gut (leading to dysbiosis) on the development of central and peripheral analgesic tolerance

Glycine Transporter 1 Inhibitors: Predictions on Their Possible Mechanisms in the Development of Opioid Analgesic Tolerance

The development of opioid tolerance in patients on long-term opioid analgesic treatment is an unsolved matter in clinical practice thus far. Dose escalation is required to restore analgesic efficacy, but at the price of side effects. Intensive research is ongoing to elucidate the underlying mechanisms of opioid analgesic tolerance in the hope of maintaining opioid analgesic efficacy. N-Methyl-D-aspartate receptor (NMDAR) antagonists have shown promising effects regarding opioid analgesic tolerance; however, their use is limited by side effects (memory dysfunction). Nevertheless, the GluN2B receptor remains a future target for the discovery of drugs to restore opioid efficacy. Mechanistically, the long-term activation of µ-opioid receptors (MORs) initiates receptor phosphorylation, which triggers β-arrestin-MAPKs and NOS-GC-PKG pathway activation, which ultimately ends with GluN2B receptor overactivation and glutamate release. The presence of glutamate and glycine as co-agonists is a prerequisite for GluN2B receptor activation. The extrasynaptic localization of the GluN2B receptor means it is influenced by the glycine level, which is regulated by astrocytic glycine transporter 1 (GlyT1). Enhanced astrocytic glycine release by reverse transporter mechanisms as a consequence of high glutamate levels or unconventional MOR activation on astrocytes could further activate the GluN2B receptor. GlyT1 inhibitors might inhibit this condition, thereby reducing opioid tolerance

Monitoring of aquatic habitats (EUNIS: C1: Surface standing waters) in wetland mosaics using UAV photogrammetry (Middle Danube)

Monitoring and mapping aquatic habitats along the huge floodplain mosaics can be challenging. One of the potential solutions is UAV imaging and photogrammetry. The aim of this study was to explore which aquatic EUNIS habitat types can be detected from RGB orthomosaics along the four Middle Danube wetlands in Serbia. Phantom 4 FC330 (12.5MP) RGB camera within the altitude range of 60-125m, at 8 lentic ecosystems in 2019 and 2020, acquired RGB UAV imagery of the water bodies. Obtained orthomosaics were processed using object-based image analysis to develop a single layer containing different aquatic habitats. In total, 43 macrophyte taxa were recorded in the study area, forming vegetation stands of free-floating duckweeds, occasionally submerged anchored ceratophyllids, and rooted aquatic vegetation. The analysis revealed that the EUNIS habitat types dominated by floating-rooted and free-floating macrophytes can be detected with high accuracy