Strengthening the positive links between organic farming and a sustainable development of rural areas

Organic farming can play a major role in the sustainable development of rural areas. Our assumption is that it supports the finding of a new balance between societal demands for high environmental quality, the pressures resulting from competition in a world market economy and a wide array of rural development goals and initiatives. The German 'Regional Action - Rural Areas Shaping the Future' pilot programme has been implemented in order to gain best-practice models for securing the economic, ecological and social viability of rural areas and for trial-testing a new integrated, bottom-up approach. In this contribution we present the results of an analysis of the project databank of the Regional Action pilot programme. It is concluded that the projects that are being implemented aim at a reconstitution of nature-society relations, indicating that agriculture and the potential of rural areas are no longer being evaluated in mono-functional terms

Neuartige Wege des Handelns und Denkens : Innovationsprozesse im ländlichen Raum

Innovationen sind für die Anpassung der ländlichen Wirtschaft an veränderte Rahmenbedingungen von besonderer Bedeutung. Die eigentlichen Innovationsprozesse entstehen dabei durch Kooperationen innerhalb von regionalen Netzwerken. Doch wie können solche Netzwerke zukünftig besser unterstützt werden

Structural and Electronic Properties of the Interface between the High-k oxide LaAlO3 and Si(001)

The structural and electronic properties of the LaAlO3/Si(001) interface are determined using state-of-the-art electronic structure calculations. The atomic structure differs from previous proposals, but is reminiscent of La adsorption structures on silicon. A phase diagram of the interface stability is calculated as a function of oxygen and Al chemical potentials. We find that an electronically saturated interface is obtained only if dopant atoms segregate to the interface. These findings raise serious doubts whether LaAlO3 can be used as an epitaxial gate dielectric.Comment: 4 pages, 5 figure

Wie arbeiten Schüler in den naturwissenschaftlichen Fächern ? : Lernforschung in der Schule und im Schülerlabor Biologie als Grundlage zukünftiger Schulentwicklung

Wissenschaftsmethodische Kompetenzen und ein wissenschaftstheoretisches Verständnis der Naturwissenschaften sind Teil einer naturwissenschaftlichen Bildung. Ob Schülerinnen und Schüler diese Kompetenzen bis zum Ende ihrer Schullaufbahn überhaupt entwickeln ist aber weitgehend unbekannt. Am Institut für Biologiedidaktik arbeitet seit 2001 die Arbeitsgruppe „Wissenschaftliche Arbeitsweisen im Biologieunterricht“ an dem Ziel, aus der Sicht der Fachdidaktik Biologie grundlegende Variablen des naturwissenschaftlichen Arbeitsprozesses bei Schülern zu identifizieren, modellhaft abzubilden und theoretisch zu fassen. Ein wichtiges Instrument war dabei – neben der Feldforschung – die Einrichtung eines Schüler-Labors zur Erforschung von Schülergruppen unter standardisierten Bedingungen

Improving the Efficiency of FP-LAPW Calculations

The full-potential linearized augmented-plane wave (FP-LAPW) method is well known to enable most accurate calculations of the electronic structure and magnetic properties of crystals and surfaces. The implementation of atomic forces has greatly increased it's applicability, but it is still generally believed that FP-LAPW calculations require substantial higher computational effort compared to the pseudopotential plane wave (PPW) based methods. In the present paper we analyse the FP-LAPW method from a computational point of view. Starting from an existing implementation (WIEN95 code), we identified the time consuming parts and show how some of them can be formulated more efficiently. In this context also the hardware architecture plays a crucial role. The remaining computational effort is mainly determined by the setup and diagonalization of the Hamiltonian matrix. For the latter, two different iterative schemes are compared. The speed-up gained by these optimizations is compared to the runtime of the ``original'' version of the code, and the PPW approach. We expect that the strategies described here, can also be used to speed up other computer codes, where similar tasks must be performed.Comment: 20 pages, 3 figures. Appears in Comp. Phys. Com. Other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm

Cardiovascular and metabolic protection by vitamin e: A matter of treatment strategy?

Cardiovascular diseases (CVD) cause about 1/3 of global deaths. Therefore, new strategies for the prevention and treatment of cardiovascular events are highly sought-after. Vitamin E is known for significant antioxidative and anti-inflammatory properties, and has been studied in the prevention of CVD, supported by findings that vitamin E deficiency is associated with increased risk of cardiovascular events. However, randomized controlled trials in humans reveal conflicting and ultimately disappointing results regarding the reduction of cardiovascular events with vitamin E supplementation. As we discuss in detail, this outcome is strongly affected by study design, cohort selection, co-morbidities, genetic variations, age, and gender. For effective chronic primary and secondary prevention by vitamin E, oxidative and inflammatory status might not have been sufficiently antagonized. In contrast, acute administration of vitamin E may be more translatable into positive clinical outcomes. In patients with myocardial infarction (MI), which is associated with severe oxidative and inflammatory reactions, decreased plasma levels of vitamin E have been found. The offsetting of this acute vitamin E deficiency via short-term treatment in MI has shown promising results, and, thus, acute medication, rather than chronic supplementation, with vitamin E might revitalize vitamin E therapy and even provide positive clinical outcomes