A revision of the genus Potamium (Musci: Sematophyllaceae).

The neotropical genus Potamium as described by Mitten (1869) included species that had little more in common than a growth form adapted to a semi-aquatic habitat. Brotherus divided the genus in section Eu-Potamium and section Potamiopsis, based on peristome characters. This study shows that all species of section Eu-Potamium belong to Sematophyllum, including P. lonchophyllum which was designated as lectotype of Potamium by Buck (1990). In section Potamiopsis two species are recognized: P. vulpinum (Mont.) Mitt. (syn. nov.: Sematophyllum maguireorum Buck) and P. deceptivum Mitt. (syn. nov.: P. leucodontaceum (C.Müll.) Broth., Meiothecium negrense Mitt. and Maguireella vulpina (Mont.) Buck). The genus Potamium is characterized by capsules with an endostome consisting of a low basal membrane and filiform segments, which are often reduced in P. deceptivum. P. vulpinum is designated as lectotype of Potamium and the lectotypification of Buck is rejected. Descriptions, illustrations and a key are provided to the species of Potamium and allied semiaquatic taxa of Sematophyllum

A catalogue of the bryophytes of the Guianas : 2., Musci

This catalogue provides an annotated listing of the mosses (MUSCI) reported from the Guianas (Guyana, Surinam, French Guiana), based on work on the Moss Flora of Suriname, which is now nearing completion. In total 238 species in 90 genera are listed. A list of synonyms (including 10 new ones) and a systematic arrangement of the genera and families are also provided. The following new combinations are proposed: Callicostella guatemalensis (Bartr.), Sematophyllum lonchophyllum (Mont.), Sematophyllum pacimoniense (Mitt.) and Trichosteleum intricatum (Thér.)

Results of a botanical expedition to mount Roraima, Guyana. I. Bryophytes

A bryological inventory of the Upper Mazaruni District, Guyana (former British Guiana) yielded almost three hundred species, including 2 genera and 11 species new to science and 130 species new to the Guianas. The densely forested and very humid north slope of Mount Roraima (500-2300 m.) proved to be the richest area for bryophytes and most of the novelties were found there. The present paper provides an enumeration of the species collected with a brief characterization of their habitat. The following species are described as new: Haesselia acuminata Gradst., Plagiochila gymnocalyx Inoue, Radula gradsteinii Yamada, Radula guyanensis Yamada, Radula mazarunensis Yamada and Stenorrhipis grollei Gradst. Anastrophyllum subg. Vanaea Inoue & Gradst. from Mount Roraima is elevated to generic rank

SQUID developments for the gravitational wave antenna MiniGRAIL

We designed two different sensor SQUIDs for the readout of the resonant mass gravitational wave detector MiniGRAIL. Both designs have integrated input inductors in the order of 1.5 muH and are planned for operation in the mK temperature range. Cooling fins were added to the shunt resistors. The fabricated SQUIDs show a behavior that differs from standard DC-SQUIDs. We were able to operate a design with a parallel configuration of washers at reasonable sensitivities. The flux noise saturated to a value of 0.84 muPhi0/radicHz below a temperature of 200 mK. The equivalent noise referred to the current through the input coil is 155 fA/radicHz and the energy resolution yields 62 h

Evaluation of legibility of not properly reflecting signs

in conditions of dew or temperatures below 0 degrees C the reflection of reflecting material on signs can be suboptimal. Problems with respect to legibility under such conditions were studied, as well as subjective ratings of the signed information. Images of the signs were presented using an LCD projector. Independent variables in the experiment were age, amount of information, stimulus quality, and presentation time. Dependent variables were errors in reproduction of the names of the cities, towns or villages on the signs, and subjective ratings. It turned out that all factors both separately and additively affected the amount of errors. Positive subjective ratings coincided mainly with level of reflection, and to a lesser degree with the amount of information, presentation time and familiarity of information. Relevance to industry: Different types of reflecting material have been developed to reflect light from signs optimally. Disadvantage of some of the materials is the effect dew and temperatures below 0 degrees C can have on reflection and legibility. The study has practical consequences in terms of novelty and amount of information to be presented on such a sign. (c) 2005 Elsevier B.V. All rights reserved

Hypotheses, evidence and relationships: The HypER approach for representing scientific knowledge claims

Biological knowledge is increasingly represented as a collection of (entity-relationship-entity) triplets. These are queried, mined, appended to papers, and published. However, this representation ignores the argumentation contained within a paper and the relationships between hypotheses, claims and evidence put forth in the article. In this paper, we propose an alternate view of the research article as a network of 'hypotheses and evidence'. Our knowledge representation focuses on scientific discourse as a rhetorical activity, which leads to a different direction in the development of tools and processes for modeling this discourse. We propose to extract knowledge from the article to allow the construction of a system where a specific scientific claim is connected, through trails of meaningful relationships, to experimental evidence. We discuss some current efforts and future plans in this area