307 research outputs found

    Characeen-Wiederfunde im Bereich Teutschental - Röblingen - ein Nachtrag zur Roten Liste der Algen des Landes Sachsen-Anhalt

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    Der ehemalige Salzige See, eine natĂŒrliche Binnensalzstelle deren Geologie in HOYNINGEN-HUENE (1959) ausfĂŒhrlich beschrieben ist, wies offenbar bis zu seinem Verschwinden um 1890 eine reichhaltige Characeenflora auf. Belege dafĂŒr finden sich nicht nur in den regional benachbarten Herbarien der UniversitĂ€t Halle bzw. des Herbariums Haussknecht in Jena, auch in Kopenhagen, Stockholm, Helsinki und Montpellier sind Belege von z. B. Chara erinita (Synonym von Ch. canescens) aus dem Jahr 1853 anzutreffen, beschriftet von ALEXANDER BRAUN (1805-1877) mit "Am Mansfelder Salzsee in ThĂŒringen". Vor allem der intensiven SammeltĂ€tigkeit von A. BRAUN und O. BULNHEIM (1820-1865) verdanken wir eine gute Kenntnis ĂŒber die ehemaligen Characeen-Vorkommen dieses Sees, der als bekannte Binnensalzstelle die Aufmerksamkeit vieler Botaniker auf sich zog und phykologisch als "locus elassieus" der Art Chara intermedia A. BRAUN in BRAUN, RABENHORST et STITZENBERGER 1859 auch eine bleibende internationale Bekanntheit erlangte (vgl. auch BLÜMEL 2004)

    Über die Hausdorff-Dimension der Juliamenge von Funktionen endlicher Ordnung

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    Das Hauptresultat dieser Arbeit ist der Satz,dass fĂŒr eine ganze transzendente Funktion endlicher Ordnung aus der sogenannten Eremenko/Lyubich-Klasse die Hausdorff-Dimension der Juliamenge dieser Funktion gleich zwei ist.Der Satz stellt eine Verallgemeinerung der SĂ€tze von Curt McMullen (1987),Masahiko Taniguchi (2001) und Krzysztof Baranski (2006) dar

    Aberrant haplostichous cortication of Chara tomentosa - another argument for matrix keys

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    A population of Chara tomentosa with haplostichous cortication was found in Sardinia (Italy). Correct identification by means of the characters used by commonkeys would be impossible, the specimens would have been regarded as C. canescens irrespective of the fact that C. tomentosa exhibit a unique character (two celled rows of branchlet cortex at the lowermost section). This note is a plea for keys allowing for identification by means of all characters in parallel instead of the commonly used hierarchical ones at least as an addition for the determination of untypical or non-fertile specimen

    Influence of Cutting Speed in Turning and Force in Subsequent Diamond Smoothing on Magnetic Properties of Steel 100Cr6

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    Magnetic properties are known to be crucial in the application of electrical steel and they are therefore covered by manifold studies. Other ferromagnetic materials are out of scope in this respect, even if the importance of magnetism of conventional steel is evident. Additionally, there is a contradiction regarding the major influence on magnetic properties. Machining, transport, and storage are possible influencing variables. In the experimental investigations, specimens consisting of the bearing steel 100Cr6 are machined by turning and partly by subsequent diamond smoothing. While machining using several cutting speeds and smoothing forces, the thermoelectrical voltage, current, and the components of the resultant force are recorded. The results show how the nearsurface plastic deformations evolve throughout the machining process. Additionally, it was found that the magnetic properties and other properties of the surface layer are influenced in different ways depending on turning and diamond smoothing parameters. Correlations between in situ and ex situ measured values are shown. This study aims to solve the aforementioned question by quantification of machining impacts of cutting speed in turning and force in diamond smoothing and its dependence on transport and storage

    Vertical migration of phytoplankton in coastal waters with different UVR transparency

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    Background: The vertical migration of phytoplankton was investigated in natural waters using in situ fluorescence profiling, chlorophyll a concentrations and life counts at two study sites differing in coloured dissolved organic matter (cDOM) concentrations. The data from the corresponding water depths (50-cm intervals down to 10 m) and times (hourly, before dawn to sunset, several days) were related to the highly resolved (2 nm) underwater ultraviolet radiation (UVR)/photosynthetic active radiation (PAR) transparency (290 to 700 nm). Results: Chlorophyll a maxima of mainly motile dinoflagellates were observed in situ at all days and at both study sites (open marine, brackish waters), independent on prevailing weather conditions or cDOM concentrations. Phytoplankton migration was triggered solely by irradiance in the 400- to 700-nm wavelength range (PAR) at the particular water depth, irrespective of PAR/UVR ratios and surface UVR (290 to 400 nm), after an illumination period of about 40 min. Interestingly, the PAR tolerance levels of the phytoplankton, which have been lower in cDOM-rich waters, matched their light acclimation values determined by parallel PAM measurements. Conclusions: The response of the phytoplankton to PAR is not a sufficient protection strategy versus increasing UVR levels, which might have wide ecological implications beyond the level of primary producers to impact important ecosystem functions such as the delicate trophic interactions

    Trophic ecology and seasonal occurrence of two Red List fish species in the Western Baltic Sea - two of a kind?

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    Improving the conservation status and the management of Red List species requires knowledge on the biology and distribution of the organisms as well as an evaluation of the appropriateness of management measures. This study provides information on the trophic ecology and seasonal abundances of two Red List fish species from the Western Baltic Sea, snake blenny Lumpenus lampretaeformis (Walbaum, 1792), classified as “critically endangered” according to the German Red List, and eelpout, Zoarces viviparus (Linnaeus, 1758), classified as “near threatened” based on the HELCOM Red List. Beam trawl surveys were conducted to document abundances of both species in summer and winter in a marine protected area (MPA), where mobile bottom-contacting fishing gears will be excluded in the near future. The MPA is located in the German EEZ (exclusive economic zone) and aims to protect sandbank and reef habitats. Stomach content and stable isotope analyses (nitrogen and carbon) were performed to examine the diet of eelpout and snake blenny. To be able to position the two fish species in the food web, stable isotopes of macrozoobenthos, POM (particulate organic matter) and sand goby (Pomatoschistus minutus) were analysed as well. Eelpout and snake blenny were present in the study area in summer and winter, but reached higher abundances in summer. Diet composition overlapped strongly reflected by a similar trophic level, indicating potential food competition of the two species. Prey items were dominated by macrozoobenthos (Mollusca, Annelida, Arthropoda). Our study provides new information on the trophic position and seasonal abundance of the two fish species within an area soon to be placed under protection from mobile bottom-contact fishing. It therefore also provides a baseline to evaluate potential positive repercussions following the exclusion of mobile bottom-contacting fishing gears and might thus help to increase the understanding of fishing impacts on benthic ecosystems contributing to more effective conservation and management measures

    Efficacy of Budesonide Orodispersible Tablets as Induction Therapy for Eosinophilic Esophagitis in a Randomized Placebo-Controlled Trial.

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    BACKGROUND & AIMS: Swallowed topical-acting corticosteroids are recommended as first-line therapy for eosinophilic esophagitis (EoE). Asthma medications not optimized for esophageal delivery are sometimes effective, although given off-label. We performed a randomized, placebo-controlled trial to assess the effectiveness and tolerability of a budesonide orodispersible tablet (BOT), which allows the drug to be delivered to the esophagus in adults with active EoE. METHODS: We performed a double-blind, parallel study of 88 adults with active EoE in Europe. Patients were randomly assigned to groups that received BOT (1 mg twice daily; n = 59) or placebo (n = 29) for 6 weeks. The primary end point was complete remission, based on clinical and histologic factors, including dysphagia and odynophagia severity ≀2 on a scale of 0-10 on each of the 7 days before the end of the double-blind phase and a peak eosinophil count <5 eosinophils/high power field. Patients who did not achieve complete remission at the end of the 6-week double-blind phase were offered 6 weeks of open-label treatment with BOT (1 mg twice daily). RESULTS: At 6 weeks, 58% of patients given BOT were in complete remission compared with no patients given placebo (P < .0001). The secondary end point of histologic remission was achieved by 93% of patients given BOT vs no patients given placebo (P < .0001). After 12 weeks, 85% of patients had achieved remission. Six-week and 12-week BOT administration were safe and well tolerated; 5% of patients who received BOT developed symptomatic, mild candida, which was easily treated with an oral antifungal agent. CONCLUSIONS: In a randomized trial of adults with active EoE, we found that budesonide oral tablets were significantly more effective than placebo in inducing clinical and histologic remission. Eudra-CT number 2014-001485-99; ClinicalTrials.gov ID NCT02434029

    A review on the distribution and habitat features of Chara canescens in the Iberian Peninsula: sexual populations revisited

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    Chara canescens, mainly distributed in Europe and the African Mediterranean coast, is the only Charophyceae species capable of reproducing parthenogenetically, the asexual populations being common; however, the sexual ones are rare. In this study we compile all the literature and herbaria data concerning the presence of C. canescens in the Iberian Peninsula and the Balearic Islands over several decades, analysing the historical and spatial distribution of the species and the limnological characteristics of its habitats. A decline in the number of records in the literature and herbarium sheets since 2010 was detected. Most of the populations are concentrated in Castilla-La Mancha, Andalucía and Castilla-León. The species lives in brackish waterbodies, both in coastal areas and endorheic shallow small lakes, and the majority of these locations do not exhibit a good conservation status. The only three locations with sexual populations previously cited in the literature (Bodón Blanco –Valladolid- and Las Eras –Segovia- lakes and Lucio Largo –Doñana-) were revisited in June 2023. Sexual populations of C. canescens in the two former lakes occurred, but the lake in the Doñana National Park was completely dry. Two new sexual populations of the species were found in La Iglesia and Caballo Alba lakes (Segovia), increasing the citation to five sexual populations. A description of population (coverage, male:female ratio) and individual (reproductive features) variables for the four C. canescens sexual populations are provided. The analysed limnological variables (water chemistry, other hydrophytes and marginal vegetation) showed that the lakes harbouring these populations exhibited signs of pollution, altered and unstructured marginal vegetation, etc. The genetic diversity of the species depends on the sexual populations, which are very rare in Europe, and are mainly concentrated in Spain. Therefore, the preservation of these inner brackish-water habitats is essential for the implementation of transnational effective conservation measures to protect this relevant and particular species

    Ecology of charophytes – permanent pioneers and ecosystem engineers

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    For almost a century, charophytes have been regarded as a group that is confined to low-nutrient-clear water conditions. In light of recent research, this generalisation of the ecological niche dimensions of charophytes has changed and now includes more facets of ecological existence. In this review, the current knowledge with respect to species-specificity as well as temporal aspects – ontogenetic and successional ones – of the ecological requirements of charophytes are presented and discussed. This review identifies new directions for ecological research on charophytes as well as knowledge gaps to be filled, not just for reasons of academic curiosity, but also for applied purposes such as lake restoration, bioremediation and bioindication of water quality and water regime
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