Erfassung von Kleinsäugern durch Schüler:Ein Unterrichtsprojekt zum Erlernen biologischer Methoden-Kompetenzen

Mit Schülern einer 9. Klasse der Werner-von-Siemens Realschule (Gladbeck) sind in dem Landschaftsschutzgebiet „Wittringer Wald“ bei Gladbeck die dort vorkommenden Kleinsäu- gerarten erfasst worden. Die Daten sind von landesweitem Interesse und dienen der Erstel- lung eines Verbreitungsatlasses einheimischer Säugetierarten. Bei dem Natur begegnenden Projekt konnten die Schüler neben der Erweiterung ihrer Artenkenntnis methodische Kompetenzen erlangen, die für exaktes biologisches Arbeiten unerlässlich sind.<br

Polarizing optics in a spider eye

Many arthropods including insects and spiders exploit skylight polarization for navigation. One of the four eye pairs of the spider Drassodes cupreus is dedicated to detect skylight polarization. These eyes are equipped with a tapetum that strongly plane-polarizes reflected light. This effectively enhances the polarization-sensitivity of the photoreceptors, improving orientation performance. With a multidisciplinary approach, we demonstrate that D. cupreus exploits reflective elements also present in non-polarizing tapetal eyes of other species such as Agelena labyrinthica. By approximately orthogonal arrangement of two multilayer reflectors consisting of reflecting guanine platelets, the tapetum uses the mechanism of polarization by reflection for polarizing reflected light

Wicked problems and clumsy solutions: Planning as expectation management

In 1973, Horst W Rittel and Malvin A Webber introduced the term ‘wicked problem’ in planning theory. They describe spatial planning as dealing with inherent uncertainty, complexity and inevitable normativity. This contribution picks up the concept of wicked problems, reflects on it from a planning-theoretical perspective, and proposes the use of Cultural Theory’s concept of clumsy solutions as a response to wicked planning problems. In discussing public participation processes in spatial planning, it is then shown what clumsy solutions mean for spatial planning. The four rationalities of Cultural Theory are then used to explain why public participation in planning can become wicked, and how these rationalities provide a response that copes with this wickedness

The relationship between financial and tax accounting in Germany — the authoritativeness and reverse authoritativeness principle

This paper focuses on the traditionally close relationship between financial and tax accounting in Germany by looking first at the historical developments. The so-called authoritativeness principle dates back to the late 19th century. By describing the different facets of the authoritativeness and the reverse author-itativeness principle, the reader will get a good overview of the historical relationship. Furthermore, the role of the highest fiscal court and the influence of some of its decisions is presented in detail. After discussing regulations concerning deferred taxation and methods of calculating those deferred taxes, the paper concludes with an estimation of future development, where it will be shown that the close relationship between commercial and tax accounts is politically stable, but that changes might be ahead with respect to the recent developments in the international accounting harmonisation debate.