Constructing Improved Overlap Fermions in QCD

We describe an explicit construction of approximate Ginsparg-Wilson fermions for QCD. We use ingredients of perfect action origin, and further elements. The spectrum of the lattice Dirac operator reveals the quality of the approximation. We focus on beta =6 for optimisation. Such fermions are intended to be inserted into the overlap formula. Hence we also test the speed of convergence under polynomial evaluation of the overlap formula.Comment: 5 pages, poster presented at Lattice 2000 (Improvement and Renormalisation

Genomewide Expression Analysis in Zebrafish mind bomb Alleles with Pancreas Defects of Different Severity Identifies Putative Notch Responsive Genes

10.1371/journal.pone.0001479PLoS ONE3

Species Delimitation in Taxonomically Difficult Fungi: The Case of Hymenogaster

False truffles are ecologically important as mycorrhizal partners of trees and evolutionarily highly interesting as the result of a shift from epigeous mushroom-like to underground fruiting bodies. Since its first description by Vittadini in 1831, inappropriate species concepts in the highly diverse false truffle genus Hymenogaster has led to continued confusion, caused by a large variety of prevailing taxonomical opinions.In this study, we reconsidered the species delimitations in Hymenogaster based on a comprehensive collection of Central European taxa comprising more than 140 fruiting bodies from 20 years of field work. The ITS rDNA sequence dataset was subjected to phylogenetic analysis as well as clustering optimization using OPTSIL software.Among distinct species concepts from the literature used to create reference partitions for clustering optimization, the broadest concept resulted in the highest agreement with the ITS data. Our results indicate a highly variable morphology of H. citrinus and H. griseus, most likely linked to environmental influences on the phenology (maturity, habitat, soil type and growing season). In particular, taxa described in the 19(th) century frequently appear as conspecific. Conversely, H. niveus appears as species complex comprising seven cryptic species with almost identical macro- and micromorphology. H. intermedius and H. huthii are described as novel species, each of which with a distinct morphology intermediate between two species complexes. A revised taxonomy for one of the most taxonomically difficult genera of Basidiomycetes is proposed, including an updated identification key. The (semi-)automated selection among species concepts used here is of importance for the revision of taxonomically problematic organism groups in general

A contribution towards a revision of the genus Tulasnella

Redescriptions of nine species of Tulasnella are given, all based on the specimens of the Bourdot herbarium in Paris

Basidiomycetes of South-Eest Asia. 1. The genus Paraphelaria (Auriculariales)

The genus Paraphelaria is divided into Paraphelaria s. str. (with pale basidiocarps) and Aphelariopsis (with dark brown basidiocarps). Paraphelaria is restricted to South-east Asia, while Aphelariopsis occurs also in South America

An unusual form of Trechispora vaga

During an excursion of the Dutch Mycological Society to the Bois de Resteigne (prov. Namur, Belgium) in 1977, a curious lignicolous clavate fungus was found growing out of a resupinate basidiocarp. Since the clavate body had the same colour as the resupinate part, a possible relationship between the two parts was supposed but seemed highly improbable since no such large structures connected with a thin resupinate basidiocarp are known up to now. The resupinate part showed a yellowish-brownish colour, stained slightly reddish in a diluted solution of KOH and was easily identified as Trechispora vaga (Fr.) Liberta, owing to its monomitic hyphal system, inflated and clamped hyphae, small four-spored basidia which often develop a lateral, basal outgrowth (pleurobasidia), and small, hyaline, inamyloid spores densely covered with warts. The clavate body was hanging out of the centre of the resupinate part and was up to 12 cm long and 9 cm wide. The point of attachement was rather narrow, ranging from a few millimeters in the small body to a few centimeters in the larger one. The surface was yellowish and showed at the marginal parts small, cup-shaped depressions caused by guttation drops. A longitudinal section reveals a yellowish context with small, darker spots (much more pronounced in dried condition) and a distinct concentrical zonation, probably demonstrating the successive growth of the fungus. The whole clavate body is sterile and shows no traces of hymenial formation or conidium production. The hyphal structure is monomitic and shows the same cylindrical, partly inflated hyphae which deviate in no way from the hyphae of the underlying perfect state. There is no doubt that the sterile, clavate structures belong to Trechispora vaga, with the resupinate basidiocarp of which they were intimately connected

On some Aphyllophorales from Australia

A collection of Aphyllophorales from Australia and Tasmania has been studied. Fifteen species have been identified and the following new taxa are described: Amaurohydnum flavidum gen. et spec. nov., Amauromyces pallidus gen. et spec. nov., Hyphoderma cinnamomeum, Lindtneria pellicularis, Resinicium luteum spp. nov. The new combination Radulodon calcareus (Cooke & Massee) is proposed