1,721,039 research outputs found
FIGURES 8–11 in Anthracoidea obtusatae (Anthracoideaceae, Ustilaginales), a new smut fungus on Carex obtusata (Cyperaceae) from Central Asia
No full textFIGURES 8–11. Anthracoidea sp. on Carex obtusata from Canada (DAOM 28184). 8–9. Spores in LM. 10–11. Spores in SEM. Scale bars: 8–9 = 10 µm, 10–11 = 5 µm.Published as part of Denchev, Teodor T., Denchev, Cvetomir M., Begerow, Dominik & Kemler, Martin, 2023, Anthracoidea obtusatae (Anthracoideaceae, Ustilaginales), a new smut fungus on Carex obtusata (Cyperaceae) from Central Asia, pp. 139-148 in Phytotaxa 595 (2) on page 143, DOI: 10.11646/phytotaxa.595.2.2, http://zenodo.org/record/790583
Interaction between growth environment and host progeny shape fungal endophytic assemblages in transplanted Fagus sylvatica
No full textNectar sugars and bird visitation define a floral niche for basidiomycetous yeast on the Canary Islands
Full text linkStudies on the diversity of yeasts in floral nectar were first carried out in the late 19th century. A narrow group of fermenting, osmophilous ascomycetes were regarded as exclusive specialists able to populate this unique and species poor environment. More recently, it became apparent that microorganisms might play an important role in the process of plant pollination. Despite the importance of these nectar dwelling yeasts, knowledge of the factors that drive their diversity and species composition is scarce
Die Gattung Amorphophallus Blume (Araceae): phylogenetische Untersuchungen und evolutionäre Muster
No full textThe genus Amorphophallus (ca. 237 species) is one of the largest genera of the Araceae and morphologically very diverse. The high species number and the high morphological variation make the understanding of the evolutionary history of the genus challenging. Therefore, in Publ.1, a new molecular phylogenetic analysis using nuclear (ITS1) and plastid (rbcL and matK) sequences based on 157 species is conducted and the resulting phylogenetic tree is used to delimit four subgenera. Moreover, several morphological and biochemical characters, some of which are related to mimicry, are explored in the phylogenetic context, demonstrating the congruence between molecular and some morphological and biochemical traits. However, several species complexes are difficult to resolve. Subsequently, the species boundaries are explored in Publ. 2 through the creation of artificial hybrids. As for the traits related to mimicry, at least two types of mimicry are encountered in several Amorphophallus species. One is a unique type of defensive colouration, petiolar lichen mimicry, providing the fleshy petiole the look of an old woody stem. Lichen mimicry in Amorphophallus has been previously described; however, in a few species only. Therefore, in Publ. 3, defensive colouration is explored in 138 Amorphophallus species, with an emphasis on lichen-like patterns. Mimicry of specific lichen types is identified in 69% of the investigated Amorphophallus species and the results are discussed in the context of the phylogenetic analysis. Deceit flowers, more precisely oviposition-site mimicry, is the second type of mimicry. The inflorescences mimic substrates, usually decomposing organic matter, which are used by Coleoptera and Diptera for feeding or breeding. Amorphophallus species are assumed to have specialised plant-pollinator interactions, involving specific pollinators, which in turn have contributed to the species richness of the genus. However, the available information about Amorphophallus pollinators is scarce; moreover, several reports are anecdotal. Therefore, the observations on visitors and pollinators in Amorphophallus are compiled, reviewed and discussed and the specificity of the plant-pollinator interaction is explored in Publ. 4. The key element of oviposition-site mimicry are the scent compounds. In previous investigations, the scent compounds of 92 Amorphophallus species have been identified and categorised to explore the evolution of floral odours in Amorphophallus. However, only few distinct evolutionary trends could be identified. One possible cause that has not been previously discussed, is intraspecific odour polymorphism. Consequently, the emitted scent compounds in Amorphophallus and the subjective odour classifications are reviewed and screened for odour polymorphism in Publ. 5. Significant odour polymorphism is identifiable in some Amorphophallus species, underlining the necessity for more investigations assessing the intraspecific variation of emitted scent compounds. Publ. 6 addresses thermogenesis, a floral temperature increase assumed to enhance scent volatilization during anthesis. The floral temperature of 80 Amorphophallus species has been measured and the resulting temperature curves have been used to explore and discuss the impact of thermogenesis on the evolution of the genus. The temperature curves show an unprecedented variation within the genus; moreover, the functionality of thermogenesis remains contentious, calling for further investigations. Lastly, using 36 Amorphophallus species, a phylogenomic study is conducted in Publ. 7, investigating the interrelationship between the main clades and providing a timeline for the evolution of the genus. For the first time, a phylogenetic hypothesis is presented that resolves the interrelationship between the African and the Asian clades. In a final chapter, the morphological variation is discussed in regard to the molecular phylogeny and evolutionary constraints. Moreover, further aspects of defensive colouration, odour polymorphism, thermogenesis and the plant-pollinator interaction are discussed
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
Tree mycorrhizal type and tree diversity effects on the structure and functional potential of forest belowground microbial communities
Full text linkThis thesis explored the impact of tree mycorrhizal types and species diversity on forest belowground microbial communities. It revealed that tree mycorrhizal types and diversity significantly influenced soil bacteria and fungi, with increased tree diversity leading to community convergence. This convergence was further influenced by various environmental factors. Network analysis indicated that mycorrhizal types affected microbial assembly and nutrient cycling potential, with high tree diversity promoting rich functional potential. Additionally, the study found that the composition of root-associated fungal communities was closely linked to fungal phylogeny rather than taxa abundance. At high tree diversity, fungal communities across different mycorrhizal types became similar. Overall, the thesis underscored the importance of tree mycorrhizal types and diversity in the dynamics of forest microbial ecosystems, providing valuable insights for the effective forest management strategies.Diese Dissertation untersuchte den Einfluss von Baum Mykorrhiza Typen und Artenvielfalt auf mikrobielle Waldgemeinschaften im Untergrund. Mykorrhiza Typen und Diversität beeinflussen Bodenbakterien und -pilze signifikant, wobei eine erhöhte Baumdiversität zur Konvergenz der Gemeinschaften führt, beeinflusst durch Umweltfaktoren. Netzwerkanalysen zeigten, dass Mykorrhiza-Typen die mikrobielle Zusammensetzung und das Nährstoffkreislaufpotenzial beeinflussen. Hohe Baumdiversität fördert ein reichhaltiges funktionelles Potenzial. Die Studie ergab außerdem, dass die Zusammensetzung von wurzelassoziierten Pilzgemeinschaften eng mit der Pilzphylogenie zusammenhängt. Bei hoher Baumdiversität werden Pilzgemeinschaften verschiedener Mykorrhiza-Typen ähnlich. Insgesamt betont die Arbeit die Bedeutung von Baum-Mykorrhiza-Typen und Diversität in der Dynamik von Waldmikrobiomen und bietet wertvolle Einblicke für effektive Waldmanagementstrategien
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
