1,721,117 research outputs found
Tillich’s Method of Correlation:Wessel Stoker in discussion with Dirk-Martin Grube
No full textThe first round of the discussion is on Paul Tillich’s famous method of correlation. This method implies that the theological answers are connected with the philosophically-existentialist questions humans ask (rather than being unconnected as in Barthianism). Wessel Stoker worries that this method may privilege Christianity and a particular concept of God over other (quasi-)religions and other concepts in unwarranted ways. Dirk-Martin Grube considers those worries unfounded, given the function Tillich ascribes to this method. In the second round, Stoker insists that the method of correlation is ontologically more heavily loaded than Grube suggests and connects this method with the (religious) a priori. In his response, Grube suggests that Tillich’s a priori has different functions than Stoker assumes
Effects of Growth Media on the Diversity of Culturable Fungi from Lichens
Full text linkMicroscopic and molecular studies suggest that lichen symbioses contain a plethora of associated fungi. These are potential producers of novel bioactive compounds, but strains isolated on standard media usually represent only a minor subset of these fungi. By using various in vitro growth conditions we are able to modulate and extend the fraction of culturable lichen-associated fungi. We observed that the presence of iron, glucose, magnesium and potassium in growth media is essential for the successful isolation of members from different taxonomic groups. According to sequence data, most isolates besides the lichen mycobionts belong to the classes Dothideomycetes and Eurotiomycetes. With our approach we can further explore the hidden fungal diversity in lichens to assist in the search of novel compounds
Extremotolerant fungi from alpine rock lichens and their phylogenetic relationships.
Full text linkFungi other than the lichen mycobiont frequently co-occur within lichen thalli and on the same rock in harsh environments. In these situations dark-pigmented mycelial structures are commonly observed on lichen thalli, where they persist under the same stressful conditions as their hosts. Here we used a comprehensive sampling of lichen-associated fungi from an alpine habitat to assess their phylogenetic relationships with fungi previously known from other niches. The multilocus phylogenetic analyses suggest that most of the 248 isolates belong to the Chaetothyriomycetes and Dothideomycetes, while a minor fraction represents Sordariomycetes and Leotiomycetes. As many lichens also were infected by phenotypically distinct lichenicolous fungi of diverse lineages, it remains difficult to assess whether the culture isolates represent these fungi or are from additional cryptic, extremotolerant fungi within the thalli. Some of these strains represent yet undescribed lineages within Chaethothyriomycetes and Dothideomycetes, whereas other strains belong to genera of fungi, that are known as lichen colonizers, plant and human pathogens, rock-inhabiting fungi, parasites and saprotrophs. The symbiotic structures of the lichen thalli appear to be a shared habitat of phylogenetically diverse stress-tolerant fungi, which potentially benefit from the lichen niche in otherwise hostile habitats
Bacteria and non-lichenized fungi within biological soil crust.
No full textMicrobial fungi and bacteria are ubiquitous, occurring in highly enriched concentrations in biological soil crusts (biocrusts), as compared to the surrounding uncrusted soil. Nevertheless, their diversity can hardly be estimated without molecular biology methods. Only the macroscopic phenotypes of lichen-forming fungal species, which may dominate the landscape in soil crust habitats, allow a more or less secure determination to species level even in the field. Lichens in biocrusts have therefore long been studied (see Chap. 1 by Lange and Belnap) and their diversity and ecosystem services specifically addressed in Chap. 7 by Rosentreter et al. Knowledge on the diversity of non-lichenized fungi in biocrusts is still quite limited, whereas investigation of bacterial communities has received global attention in the past decade. This chapter aims to review the current state of research on bacterial and fungal community composition in biocrusts
Extremotolerant black fungi from rocks and lichens.
No full textIn contrast to the majority of fungi, which live more or less comfortably inside of hosts or substrates, some lineages have specialised to thrive on exposed surfaces. With little competition on nutrient-deprived conditions, such a stressful lifestyle also requires adaptations to fluctuations of hydration, among other challenges. Fungi in these situations also need to shield their cell content from excessive radiation using various kinds of pigments in their cell walls. The symbiotic thalli of lichen-forming fungi are one example on how to cope with conditions of exposed surfaces. Lichenforming fungi develop diverse forms of characteristically compacted mycelial morphologies to filter light to sheltered photosynthetic algae. Another large group of fungi does not depend on symbiotic partners, but it is characterised by dark pigments, and unlike lichens, these fungi may tolerate much higher levels of air pollution. These
‘black’ fungi, as they are commonly called, are the focus of this chapter. We provide an overview of the current understanding of diversity and taxonomy of black fungi and review their phenotypic traits. As we previously recognised ecological and evolutionary links of black fungi with the lichen symbiosis, we also discuss first results from co-culture experiments of black fungi with algae. Finally, we also review first insights gained from -omics approaches. The phenotypes of black fungi have evolved in different lineages of ascomycetes. Under the extremes of abiotic conditions, the typical morphology is usually restricted to vegetative mycelia with insufficient diagnostic characters for species recognition. Hence it is practically impossible to identify the species directly in the environment or with a stereomicroscope. Diagnostic phenotypic characters are often expressed under controlled laboratory conditions, even though species commonly lack sexual structures. Analyses of DNA sequence data are the only way to prove the relationship of species with similar morphology and to place these fungi in a phylogenetic framework. Molecular approaches showed both that many lineages exist which have not been named so far while described taxa turned out to be polyphyletic (e.g. Ertz et al. 2014). DNA data are still of limited use to recognise species as little is known about the genetic variation within species, but they clearly showed that black fungi are phylogenetically more diverse than previously thought and that they primarily belong to two lineages of ascomycetes, the early diverging clades of Dothideomycetes and Eurotiomycetes in Ascomycota
Reply to Henk van den Belt’s and Rick Benjamins’ articles:The resurrection and the subject philosophy
No full textIn the first part, Dirk-Martin Grube follows Paul Tillich’s leads by suggesting that revelation consists primarily in knowledge of knowledge rather than knowledge of facts. Grube holds that the evidence for the resurrection is such that its historicity can neither be confirmed (against Henk van den Belt) nor denied. Rather, it should be considered to be logically undecidable. Different from Van den Belt, Grube follows Tillich by sympathizing with the independence model for relating religion to science. In the second part, Grube takes up the issue Rick Benjamins focusses on, subject philosophy. After delving into the different positions on the way in which Tillich has adopted this philosophy, Grube evaluates subject philosophy, partly deviating from Benjamins, partly agreeing with him
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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