Abundant and rare spiders on tree trunks in German forests (Arachnida, Araneae)

The spider fauna active on the bark of trees in forests on eight sites in different regions in Germany was investigated. Trunk eclectors at about 2-4 meters height on living trees were used in different regions of Germany (SW Bavaria, Hesse, Brandenburg) between 1990 and 2003. In Hesse eclectors were also used on dead beech trees (standing and lying). In this study data, mainly from beech (Fagus sylvatica) and spruce (Picea abies), from May to October are compared – whole year samples (including winter) are only available from Hesse. A total of 334 spider species were recorded with these bark traps, i.e. about one third of the spider species known from Germany. On average, each of the eight regions yielded 140.5 (± 26.2) species, each single tree 40.5 (± 12.2) species and 502 (±452) adult spiders per season (i.e. May to Oct.). The 20 most abundant species are listed and characterised in detail. Six of the 20 species were not known to be abundant on bark, three prefer conifers and three beech/broadleaf. Even in winter (December-March) there was a remarkably high activity on the trunks. However, only a few species occur exclusively or mainly in winter. Finally, the rarity of some bark spider species is discussed and details (all known records in Germany, phenology) of four of them are presented (Clubiona leucaspis, Gongylidiellum edentatum, Kratochviliella bicapitata, Oreonetides quadridentatus). The diversity and importance of the spider fauna on bark in Central Europe is still underestimated

Fox could have made Werrity a Special Adviser but he chose not to, thereby keeping his role informal and less constrained

On Friday, the Defence Secretary Liam Fox was forced to resign after questions were raised concerning his relationship with Adam Werritty, and his nebulous links to unspecified backers, business contacts and overseas officials. Andrew Blick looks at the historical roots of the Special Advisor role for explanations of how these situations can come about

Taxonomic note on Aculepeira lapponica (Arachnida: Araneae: Araneidae)

Caused by the similarity with the type species Aculepeira packardi and with A. ceropegia we confirm the combination Aculepeira lapponica for the arctic araneid Aranea lapponica Holm, 1945

Weltweite Kataloge und Artenzahlen der Spinnentierordnungen (Arachnida)

Volume: 41Start Page: 41End Page: 4

Spontaneous Symmetry Breaking in Two Coupled Nanomechanical Electron Shuttles

We present spontaneous symmetry breaking in a nanoscale version of a setup prolific in classical mechanics: two coupled nanomechanical pendulums. The two pendulums are electron shuttles fabricated as nanopillars and placed between two capacitor plates in a homogeneous electric field. Instead of being mechanically coupled through a spring they exchange electrons, i.e. they shuttle electrons from the source to the drain 'capacitor plate'. Nonzero DC current through this system by external AC excitation is caused via dynamical symmetry breaking. This symmetry-broken current appears at sub- and superharmonics of the fundamental mode of the coupled system

Development and Evaluation of "Where Are We?" Map-Skills Software and Curriculum

The "Where are We?" software and lessons are designed to help children in grades two through four learn to "translate" between the visually-perceived world that they sense around them, and the schematic representation of that landscape on a map. Field-based tests were developed to examine students' ability to absorb information in the real world and to transfer it onto a map and, conversely, the ability to absorb information from a map and transfer it into an action in the real world. Formative evaluation of a prototype version of "Where are We?" resulted in the following improvements in the instructional materials: more and prompter feedback for students, additional assessment tools for teachers, development of lessons to model successful map-using strategies, development of lessons to overcome common misconceptions, and replacement of text-based instructions with a voiceover demo. Educational levels: Graduate or professional

LOGUNOV, D.V. & Y.M. MARUSIK (2000): Catalogue of the jumping spiders of northern Asia (Arachnida, Araneae, Salticidae). 299 Seiten; Moskau (KMK Sci. Press). Englisch. ISBN 5-87317-081-9 [Rezension]

Der stabil gebundene Band, gedruckt auf Hochglanzpapier im A5-Format, wirkt schon auf den ersten Blick recht ansprechend. Der Katalog umfasst ein riesiges Areal: Rußland vom Ural bis zum Pazifik, die Mongolei, beide Teile Koreas, sowie den Norden von Kasachstan, China und Japan (Hokkaido) - das Gebiet ist also in erster Linie geografisch definiert. Ein Blick auf einen Atlas/Globus zeigt, dass es (bis auf das flache sumpfige Westsibirien) in weiten Teilen Mittel- und vor allem Hochgebirgsareale enthalt. Dazu kommen natürlich noch Habitate an Küsten, Fluss- und Seeufem, Sümpfe, usw