Clonal organisms with occasional sex are important for our general understanding of the costs and benefits that maintain sexual reproduction. Cyclically parthenogenetic aphids are highly variable in their frequency of sexual reproduction. However, studies have mostly focused on free-living aphids above ground, whereas dispersal constraints and dependence on ant-tending may differentially affect...

Current approaches in schema mapping and matching focus on pair-wise comparison of schemas. This chapter gives an overview of how n-way comparison of schemas via a unified data model for large-scale multi-schema integration (ULMI) can benefit to schema matching and mapping processes. The approach integrates a set of input schemas into one comprehensive representation. Thus, a unified data model...

This report presents a survey of previous and more recent ultrastructural and cytochemical investigations of disease development in elm, caused by Ophiostoma novo-ulmi, with results of some comparative studies of other wilt diseases caused by f.spp., of Fusarium oxysporum and of Verticillium sp. For cytochemical studies, probes complexed to colloidal gold to detect cellulose, pectin, chitin, an...

Elms, especially Ulmus minor and U. americana, are carrying out a hard battle against Dutch elm disease (DED). This vascular wilt disease, caused by Ophiostoma ulmi and O. novo-ulmi, appeared in the twentieth century and killed millions of elms across North America and Europe. Elm breeding and conservation programmes have identified a reduced number of DED tolerant genotypes. In this study, thr...

Hydrophobins are components of microbial cell walls that contribute tocell surface hydrophobicity. The hydrophobic nature of the surfaces of many microbes, both prokaryotic and eukaryotic, is important to such processes as adhesion of pathogens to host structures and dispersa1 of aerial spores (Beever and Dempsey, 1978; Doyle and Rosenberg, 1990; Stringer et al., 1991). A class of peptide hydro...

Four new yeasts are described that were recognized as novel from nucleotide substitutions in domain D1/D2 of 26S rDNA, a region that is sufficiently divergent to allow resolution of most ascomycetous yeast species. The new species and their type strains are as follows: Pichia maclurae NRRL Y-5377T (= CBS 8671T); Pichia misumaiensis NRRL Y-17389T (= CBS 8062T); Candida mycetangii NRRL Y-6843T (=...