125 research outputs found

    Ascospore discharge, germination and culture of fungal partners of tropical lichens, including the use of a novel culture technique

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    A total of 292 lichen samples, representing over 200 species and at least 65 genera and 26 families, were collected, mainly in Thailand; 170 of the specimens discharged ascospores in the laboratory. Generally, crustose lichens exhibited the highest discharge rates and percentage germination. In contrast, foliose lichen samples, although having a high discharge rate, had a lower percentage germination than crustose species tested. A correlation with season was indicated for a number of species. Continued development of germinated ascospores into recognizable colonies in pure culture was followed for a selection of species. The most successful medium tried was 2 % Malt-Yeast extract agar (MYA), and under static conditions using a liquid culture medium, a sponge proved to be the best of several physical carriers tested; this novel method has considerable potential for experimental work with lichen mycobionts

    Salinomycin induces calpain and cytochrome c-mediated neuronal cell death

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    Salinomycin is a polyether antibiotic with properties of an ionophore, which is commonly used as cocciodiostatic drug and has been shown to be highly effective in the elimination of cancer stem cells (CSCs) both in vitro and in vivo. One important caveat for the potential clinical application of salinomycin is its marked neural and muscular toxicity. In the present study we show that salinomycin in concentrations effective against CSCs exerts profound toxicity towards both dorsal root ganglia as well as Schwann cells. This toxic effect is mediated by elevated cytosolic Na+ concentrations, which in turn cause an increase of cytosolic Ca2+ by means of Na+/Ca2+ exchangers (NCXs) in the plasma membrane as well as the mitochondria. Elevated Ca2+ then leads to calpain activation, which triggers caspase-dependent apoptosis involving caspases 12, 9 and 3. In addition, cytochrome c released from depolarized mitochondria directly activates caspase 9. Combined inhibition of calpain and the mitochondrial NCXs resulted in significantly decreased cytotoxicity and was comparable to caspase 3 inhibition. These findings improve our understanding of mechanisms involved in the pathogenesis of peripheral neuropathy and are important to devise strategies for the prevention of neurotoxic side effects induced by salinomycin

    Diversity and Functional Traits of Lichens in Ultramafic Areas: A Literature Based Worldwide Analysis Integrated by Field Data at the Regional Scale

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    While higher plant communities found on ultramafics are known to display peculiar characteristics, the distinguishability of any peculiarity in lichen communities is still a matter of contention. Other biotic or abiotic factors, rather than substrate chemistry, may contribute to differences in species composition reported for lichens on adjacent ultramafic and non-ultramafic areas. This work examines the lichen biota of ultramafics, at global and regional scales, with reference to species-specific functional traits. An updated world list of lichens on ultramafic substrates was analyzed to verify potential relationships between diversity and functional traits of lichens in different Köppen–Geiger climate zones. Moreover, a survey of diversity and functional traits in saxicolous communities on ultramafic and non-ultramafic substrates was conducted in Valle d’Aosta (North-West Italy) to verify whether a relationship can be detected between substrate and functional traits that cannot be explained by other environmental factors related to altitude. Analyses (unweighted pair group mean average clustering, canonical correspondence analysis, similarity-difference-replacement simplex approach) of global lichen diversity on ultramafic substrates (2314 reports of 881 taxa from 43 areas) displayed a zonal species distribution in different climate zones rather than an azonal distribution driven by the shared substrate. Accordingly, variations in the frequency of functional attributes reflected reported adaptations to the climate conditions of the different geographic areas. At the regional scale, higher similarity and lower species replacement were detected at each altitude, independent from the substrate, suggesting that altitude-related climate factors prevail over putative substrate–factors in driving community assemblages. In conclusion, data do not reveal peculiarities in lichen diversity or the frequency of functional traits in ultramafic areas

    Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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    Contains fulltext : 172380.pdf (publisher's version ) (Open Access

    Nieuwe Cladonia-soorten voor Nederland

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    Six new Cladoniae for the Netherlands are mentioned and their main characteristics described. Cladonia cenotea (Ach). Schaer., C. stellaris (Opiz) Pouzar et Vezda, C. subcervicornis (Vain.) DuRietz and C. symphycarpia Fik. are recorded from a single find. The first two were already labelled correctly, but not yet published. C. gonecha (Ach.) Asah. and C. rei Schaer. have been recognized by chemical methods from several localities, humous sites then C. rei seems to prefer less acid and less C. subulata (L.) Wigg., which closely resembles it

    A Conspectus of the Lichens (Lichenized Fungi) of Singapore

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    Volume: 61Start Page: 437End Page: 48

    Provisional checklist for the lichens of Chiapas

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    A list is presented of 359 lichen taxa known so far from Chiapas (Mexico). It is based on literature records and recent collections made by Breedlove and by Wolf and collaborators. The actual lichen flora of Chiapas is estimated to be certainly much larger.Se presenta una lista preliminar de 359 taxa de líquenes del estado de Chiapas, México, basada en datos de la literatura y colectas recientes de Breedlove y de Wolf y sus colaboradores. Se estima que el número total de especies para el estado es considerablemente más grande
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