16 research outputs found

    Chrysophycean stomatocysts associated with the carnivorous plants (genus Utricularia) from Jeleniak-Mikuliny Nature Reserve

    Get PDF
    An account is given of chrysophycean stomatocysts and algae occurring together with the carnivorous plants known as bladderworts, Utricularia intermedia, U. minor and U. australis, in the peat bog of Jeleniak-Mikuliny Nature Reserve. Eleven chrysophycean stomatocyst morphotypes were found, all reported for the first time from this nature reserve. Among them, two are new records for Europe (stomatocysts 330 and 208) and another two are new for Poland (stomatocysts 112 and 387). Descriptions are provided together with SEM illustrations. General data about cyanobacteria and eukaryotic algae occurring with these stomatocysts are enumerated

    In search of governing gas flow mechanism through metal solid foams

    Get PDF
    Solid foams have been intensely studied as promising structured catalytic internals. However, mechanisms governing flow and transport phenomena within the foam structures have not been properly addressed in the literature. The aim of this study was to consider such flow mechanisms based on our experimental results on flow resistance. Two mechanisms were considered: developing laminar flow in a short capillary channel (flow-through model), and flow around an immersed solid body, either a cylinder or sphere (flow-around model). Flow resistance experiments were performed on three aluminum foams of 10, 20, and 40 PPI (pores per inch), using a 57 mm ID test column filled with the foams studied. The foam morphology was examined using microtomography and optical microscopy to derive the geometric parameters applied in the model equations. The flow-through model provided an accuracy of 25% for the experiments. The model channel diameter was the foam cell diameter, and the channel length was the strut thickness. The accuracy of the flow-around model was only slightly worse (35%). It was difficult to establish the geometry of the immersed solid body (sphere or cylinder) because experiment characteristics tended to change from sphere to cylinder with increasing PPI value

    Browsers, grazers or mix-feeders? Study of the diet of extinct Pleistocene Eurasian forest rhinoceros Stephanorhinus kirchbergensis (J¨ager, 1839) and woolly rhinoceros Coelodonta antiquitatis (Blumenbach, 1799)

    Get PDF
    The wooly rhinoceros (Coelodonta antiquitatis) and forest rhinoceros (Stephanorhinus kirchbergensis) were prominent representatives of the Middle and Late Pleistocene glacial and interglacial faunas of Eurasia. Their diet has traditionally been inferred on functional morphology of the dentition and skull. In rare cases, food remains are preserved in the fossas of the teeth or as gut content. New approaches to infer diet include the study of isotopes and mesowear. Here we apply all four methods to infer the diet of these emblematic rhinoceros’ species and compare the food actually taken with the food available, as indicated by independent botanical data from the localities where the rhinoceros’ fossils were found: Gorz´ow Wielkopolski (Eemian) and Starunia (Middle Vistulian) as well as analysis of literature data. We also made inferences on the season of death of these individuals. Our results indicate that the woolly rhino in both Europe and Asia (Siberia) was mainly a grazer, although at different times of the year and depending on the region its diet was also supplemented by leaves of shrubs and trees. According to the results of isotope studies, there were important individual variations. The data show a clear seasonal variation in the isotope composition of this rhino’s diet. In contrast, Stephanorhinus kirchbergensis was a browser, though its diet included low-growing vegetation. Its habitat consisted of various types of forests, from riparian to deciduous and mixed forests, and open areas. The diet of this species consisted of selected items of vegetation, also including plants growing near both flowing and standing waters. The food remains from the fossae of the teeth indicated flexible browsing, confirming the previous interpretations based on functional morphology and stable isotopes. Long-term data from mesowear and microwear across a wider range of S. kirchbergensis fossils indicate a more mixed diet with a browsing component. The different diets of both of rhinoceros reflect not only the different habitats, but also climate changes that occurred during the Late Pleistocene

    assemblage in a low-conductivity tropical lake in the

    No full text
    variability of new chrysophyte stomatocyst forming a single-cys

    On the occurrence of Sistotrema confluens (Stereales) in Poland

    No full text
    The new Polish rccord of Sistotrema confluens Pers.: Fr. provides the back-ground to outlining the morphology (with line drawings of microscopie characters), taxonomy and site conditions of this largely neglected polypore in Poland. The new record of the fungus is an 13. in the country but the first one documented by voucher specimens

    Rekreacyjne używanie leków dostępnych w odręcznej sprzedaży: odurzanie i doping mózgu

    Get PDF
    Recreational substance use is becoming more common, especially among young people. Some anti-inflammatory or antitussive drugs exert potent psychoactive effects when they are used in large doses. Easily available over-the-counter (OTC) drugs may cause a range of effects including hallucinations or euphoria. Dextromethorphan (DXM) is particularly often used. At doses of 1.5–7.5 mg/kg body mass it induces stimulation, mood improvement, motor impairment, and used at doses higher than 7.5 mg/kg b.m., it exerts dissociative effects. Adverse reactions are especially clear when DXM was taken with alcohol or substances affecting metabolic activity of cytochrome P450 CYP2D6. Among DXM users, some cases of psychological dependence and withdrawal symptoms were observed. Long-term use of DXM may be associated with cognitive function deterioration. The abuse of Tantum Rosa (a popular gynecological anti-inflammatory drug containing benzydamine) was described mainly in Brazil, Poland and Romania. It causes hallucinations (mainly visual) and “flashbacks” (short-term hallucinations despite not being under the influence of the psychedelic compound). Pseudoephedrine, an amphetamine-like stimulant, produces mood improvement or even euphoria, hallucinations and psychosis. However, the real health threat is associated with the use of substances produced from pseudoephedrine: ephedrone and methamphetamine

    A morphotype-rich assemblage of chrysophycean stomatocysts in mountain lakes in the Cameroon Highlands, Africa

    No full text
    Based on samples collected from two mountain lakes named as Lacs Paponoun located in the Cameroon Highlands (Africa), an assemblage of chrysophycean stomatocysts was investigated using scanning electron microscopy. Twenty stomatocysts are reported and described following the guidelines of the International Statospore Working Group (ISWG). Eleven cysts are described as new morphotypes. The present study documents the largest assemblage of chrysophycean stomatocysts from the recent sediments in tropical Africa detected so far. Additionally, it provides new data on global diversity of chrysophycean stomatocysts.</p

    ff

    No full text

    Asynchronous multitrophic level regime shifts show resilience to lake browning

    No full text
    Lake browning is widespread due to increased supply of dissolved organic carbon under climate warming and nitrogen deposition. However, multitrophic level responses to lake browning are poorly understood. Our study aims to explore such responses across multitrophic levels based on sedimentary records of diatoms, chrysophyte stomatocysts and chironomids in a remote headwater lake in the Three Gorges Reservoir region, central China. Although all biotic proxies were analysed in the same core, the timing of shifts in chironomids (1886 ± 18 CE) preceded that in chrysophyte stomatocysts (∼1914 ± 10 CE) and diatoms (∼1941 ± 6 CE). Shifts in biotic communities were closely linked to rising temperature, δ15N depletion (a proxy for nitrogen deposition), δ13C enrichment (a proxy for littoral moss expansion), as well as biotic interactions, whereas the relative importance of the driving forces varied among the three biotic groups. Our results suggest that the zoobenthos grazing effect might be more important than bottom-up pathways in humic environments. Additionally, the coexistence of benthic, littoral and pelagic algae after the 1950s suggested that mixotrophic chrysophytes could reduce lake browning through heterotrophic processes and sustain the ecological equilibrium between littoral, pelagic and benthic productivity. Therefore, lake browning ecosystem regime shifts require analyses of multiple trophic levels. Our results suggest that heterotrophy may become more important in lake ecosystem carbon cycling with water brownification in Mulong Lake, as well as similar montane lakes
    corecore