59 research outputs found

    Breeding site traits of European newts (Triturus macedonicus, Lissotriton vulgaris, and Mesotriton alpestris: Salamandridae) in the Montenegrin karst region

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    We recorded the occurrence of three European newt species - the smooth newt (Lissotriton vulgaris), the eastern alpine crested newt (Triturus macedonicus), and the alpine newt (Mesotriton alpestris) - in the Montenegrin karst, as well as their breeding site characteristics. In terms of long-lasting breeding site numbers and occupation rate, the most common species is the smooth newt, followed by the alpine newt and the crested newt. The examined water bodies with­out newts showed no significant differences of aquatic habitat characteristics compared to water bodies with newts. The factors that explained most of the observed variation in newt breeding site traits were the habitat category and habitat origin. The alpine newt primarily inhabits natural lakes, while the crested newt inhabits artificial breeding sites such as lithotelma and ubao. The smooth newt is less choosy and occurs in different types of natural and artificial habitats. The aquatic requirements of Montenegrin newt species do not differ substantially in many respects from requirements of the core species range populations.Istraživano je prisustvo tri vrste evropskih mrmoljaka u crnogorskom karstu, malog (Lissotriton vulgaris), istočnog glavatog (Triturus macedonicus) i planinskog mrmoljka (Mesotriton alpestris), kao i karakteristike njihovih reproduktivnih staništa. U pogledu broja reproduktivnih staništa, mali mrmoljak je najčešća vrsta, zatim sledi planinski i na kraju istočni glavati mrmoljak. Istraživana vodena staništa bez mrmoljaka nisu pokazala značajne razlike u karakteristikama u poređenju sa vodenim staništima sa mrmoljcima. Faktori koji najbolje objašnjavaju uočenu varijabilnost karakteristika reproduktivnih staništa mrmoljaka su tip i poreklo staništa. Planinski mrmoljak primarno naseljava jezera prirodnog porekla, dok istočni glavati mrmoljak naseljava antropogena staništa (najčešće kamenice i ublove). Mali mrmoljak naseljava različite tipove staništa prirodnog ili antropogenog porekla. Osobine reproduktivnih staništa mrmoljaka Crne Gore ne razlikuju se umnogome od osobina reproduktivnih staništa populacija iz centra areala ovih vrsta.Projekat ministarstva br. 14305

    Differential expression of KCNQ1 K+ channel in tubular cells of frog kidney

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    The aim of this study was to evaluate KCNQ1 K+ channel expression in the frog kidney of Rana esculenta. KCNQ1 K+ channel, also known as KvLQT1, is the pore forming α-subunit of the IKs K+ channel, a delayed rectifier voltage-gated K+ channel, which has an important role in water and salt transport in the kidney and gastrointestinal tract. The expression of KCNQ1 K+ channel along tubular epithelium differs from species to species. In the present study the expression of KCNQ1 K+ channel in the frog kidney has been demonstrated by immunohistochemistry. The presence of KCNQ1 K+ channel was demonstrated in the epithelial cells of distal convoluted tubule and collecting duct. However, the pattern of expression of KCNQ1 K+ channel differs between distal convoluted tubules and collecting duct. All epithelial cells of distal convoluted tubules revealed basolateral expression of KCNQ1 K+ channel. On the contrary, only the single cells of collecting duct, probably intercalated cells, showed diffuse cell surface staining with antibodies against KCNQ1 K+ channel. These findings suggest that KCNQ1 K+ channel has cell-specific roles in renal potassium ion transport

    Top predators constrain mesopredator distributions

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    © The Author(s) 2017. Top predators can suppress mesopredators by killing them, competing for resources and instilling fear, but it is unclear how suppression of mesopredators varies with the distribution and abundance of top predators at large spatial scales and among different ecological contexts. We suggest that suppression of mesopredators will be strongest where top predators occur at high densities over large areas. These conditions are more likely to occur in the core than on the margins of top predator ranges. We propose the Enemy Constraint Hypothesis, which predicts weakened top-down effects on mesopredators towards the edge of top predators' ranges. Using bounty data from North America, Europe and Australia we show that the effects of top predators on mesopredators increase from the margin towards the core of their ranges, as predicted. Continuing global contraction of top predator ranges could promote further release of mesopredator populations, altering ecosystem structure and contributing to biodiversity loss

    A European Concern? Genetic Structure and Expansion of Golden Jackals (Canis aureus) in Europe and the Caucasus

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    In the first continent-wide study of the golden jackal (Canis aureus), we characterised its population genetic structure and attempted to identify the origin of European populations. This provided a unique insight into genetic characteristics of a native carnivore population with rapid large-scale expansion. We analysed 15 microsatellite markers and a 406 basepair fragment of the mitochondrial control region. Bayesian-based and principal components methods were applied to evaluate whether the geographical grouping of samples corresponded with genetic groups. Our analysis revealed low levels of genetic diversity, reflecting the unique history of the golden jackal among Europe’s native carnivores. The results suggest ongoing gene flow between south-eastern Europe and the Caucasus, with both contributing to the Baltic population, which appeared only recently. The population from the Peloponnese Peninsula in southern Greece forms a common genetic cluster with samples from south-eastern Europe (ΔK approach in STRUCTURE, Principal Components Analysis [PCA]), although the results based on BAPS and the estimated likelihood in STRUCTURE indicate that Peloponnesian jackals may represent a distinct population. Moreover, analyses of population structure also suggest either genetic distinctiveness of the island population from Samos near the coast of Asia Minor (BAPS, most STRUCTURE, PCA), or possibly its connection with the Caucasus population (one analysis in STRUCTURE). We speculate from our results that ancient Mediterranean jackal populations have persisted to the present day, and have merged with jackals colonising from Asia. These data also suggest that new populations of the golden jackal may be founded by long-distance dispersal, and thus should not be treated as an invasive alien species, i.e. an organism that is “non-native to an ecosystem, and which may cause economic or environmental harm or adversely affect human health”. These insights into the genetic structure and ancestry of Baltic jackals have important implications for management and conservation of jackals in Europe. The golden jackal is listed as an Annex V species in the EU Habitats Directive and as such, considering also the results presented here, should be legally protected in all EU member states

    Genetic Structure and Expansion of Golden Jackals (Canis aureus) in Europe and the Caucasus

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    We analyzed 65 samples of golden jackals (Canis aureus) collected in south-eastern and central Europe, the Caucasus, and from Estonia (north-eastern Europe). Microsatellite markers and partial sequences of the mitochondrial control region were used to characterize the genetic structure of jackals in the sampled regions. The main aim of the study was to identify possible source populations of the golden jackals in north-eastern Europe

    Failure analysis method for enhancing circularity through systems perspective

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    Recently, a circular economy has attracted global attention as an approach for addressing material security and resource-efficiency issues. As our societies shift toward a circular economy, manufacturers need to not only produce environmentally conscious products but to also realize reliable systems that will ensure the closure of the loops of the products, components, and materials. To do so, early-stage design is crucial to effectively and efficiently detect possible failures and then take adequate countermeasures against them. Although a few methods of failure analysis have been proposed to address environmental issues, these methods have failed to consider the cause–effect relationships among failures. This will hinder manufacturers from identifying core problems that should be addressed in a given system. Therefore, this study extends failure mode and effect analysis, which is an engineering technique used to address potential failures, by addressing the entire system reliability in relation to circularity. As a result of a case study of a manufacturer aiming to increase circularity with their products on the market, we revealed that the proposed method is useful in the early stage of design to (a) identify failure modes where effects are largely given to or received from other failures, (b) develop countermeasures effectively by addressing root causes of failures, and (c) find an opportunity to collaborate with external actors

    Losartan Improved Antioxidant Defense, Renal Function and Structure of Postischemic Hypertensive Kidney

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    Ischemic acute renal failure (ARF) is a highly complex disorder involving renal vasoconstriction, filtration failure, tubular obstruction, tubular backleak and generation of reactive oxygen species. Due to this complexity, the aim of our study was to explore effects of Angiotensin II type 1 receptor (AT1R) blockade on kidney structure and function, as well as oxidative stress in spontaneously hypertensive rats (SHR) after renal ischemia reperfusion injury. Experiments were performed on anaesthetized adult male SHR in the model of ARF with 40 minutes clamping the left renal artery. The right kidney was removed and 40 minutes renal ischemia was performed. Experimental groups received AT1R antagonist (Losartan) or vehicle (saline) in the femoral vein 5 minutes before, during and 175 minutes after the period of ischemia. Biochemical parameters were measured and kidney specimens were collected 24h after reperfusion. ARF significantly decreased creatinine and urea clearance, increased LDL and lipid peroxidation in plasma. Treatment with losartan induced a significant increase of creatinine and urea clearance, as well as HDL. Lipid peroxidation in plasma was decreased and catalase enzyme activity in erythrocytes was increased after losartan treatment. Losartan reduced cortico-medullary necrosis and tubular dilatation in the kidney. High expression of pro-apoptotic Bax protein in the injured kidney was downregulated after losartan treatment. Our results reveal that angiotensin II (via AT1R) mediates the most postischemic injuries in hypertensive kidney through oxidative stress enhancement. Therefore, blockade of AT1R may have beneficial effects in hypertensive patients who have developed ARF

    Mammal responses to global changes in human activity vary by trophic group and landscape

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    Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human–wildlife interactions along gradients of human influence.Peer reviewe
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