The upper-level taxonomic structure of current ontologies is often quite complicated and hard to understand. In this paper I analyze the ontological nature of upper-level categories, considering the necessity of splitting them according to more subtle distinctions or the opportunity of excluding them because of their limited organizational role.

A new species, Ishikawatrechus bidilatatus sp. nov., is described from the northwestern part of the Ishizuchi Range, Shikoku, Japan. The structure of the everted internal sac of the aedeagus in a fully inflated condition is observed and the taxonomic significance is discussed by comparing with a related species, I. ishiharai Uéno, 1994.

Phytochemical investigation of Laureliopsis philippiana resulted in isolation of a new bisbenzylisoquinoline alkaloid (1) named laureliopsine A. The structure was established by spectroscopic methods, including 2D homo- and heteronuclear NMR experiments. This finding of a bisbenzylisoquinoline alkaloid in Laureliopsis supports its close relationship to Atherosperma and its taxonomic segregation...

Here we describe a quantitative PCR-based approach to estimating the relative abundances of major taxonomic groups of bacteria and fungi in soil. Primers were thoroughly tested for specificity, and the method was applied to three distinct soils. The technique provides a rapid and robust index of microbial community structure.

The Antwerp database on large subunit ribosomal RNA now contains 607 complete or nearly complete aligned sequences. The alignment incorporates secondary structure information for each sequence. Other information about the sequences, such as literature references, accession numbers and taxonomic information is also available. Information from the database can be downloaded or searched on the rRN...

The normal and lateral line cycloid scales of a cyprinid fish Rutilus frisii kutum Kamenskii, 1901 have been subjected to scanning electron microscopy technique to study their detailed structure. The scales have the general morphological characteristics of the cycloid scales. In the normal scale located below the dorsal fin, the focus lies on the anterior region with few mucous pores. There is ...

Metagenomics holds the promise of greatly advancing the study of diversity in natural communities, but novel theoretical and methodological approaches must first be developed and adjusted for these data sets. We evaluated widely used macroecological metrics of taxonomic diversity on a simulated set of metagenomic samples, using phylogenetically meaningful protein-coding genes as ecological prox...

Microbial communities in engineered terrestrial haloalkaline environments have been poorly characterized relative to their natural counterparts and are geologically recent in formation, offering opportunities to explore microbial diversity and assembly in dynamic, geochemically comparable contexts. In this study, the microbial community structure and geochemical characteristics of three geograp...

Many accounts of categorization equate goodness-of-example with central tendency for common taxonomic categories; the best examples of a category are average members--those that are most similar to most other category members. In the present study, we asked 24 tree experts and 20 novices to rate goodness-of-example for a sample of 48 trees and found (1) that the internal structure of the catego...

Bacterial carbohydrate structure database (BCSDB) is an open-access project that collects primary publication data on carbohydrate structures originating from bacteria, their biological properties, bibliographic and taxonomic annotations, NMR spectra, etc. Almost complete coverage and outstanding data consistency are achieved. BCSDB version 3 and the principles lying behind it, including glycan...