JoSchKa: Jobverteilung in heterogenen und unzuverlässigen Umgebungen

In der Arbeit wird ein System zur Verteilung rechenintensiver Jobs beschrieben, das mit wenig Einarbeitungszeit genutzt werden kann und es ermöglicht, Standard-PCs mit geringem administrativem Aufwand in einen Rechenverbund zu integrieren. Ein wesentlicher Aspekt beschäftigte sich mit der Entwicklung neuartiger Verfahren, um den auf diese Weise entstehenden heterogenen Rechnerverbund mit seinen unterschiedlichsten Leistungs- und Zuverlässigkeitscharakteristika optimal mit Arbeit zu versorgen

One-stop publishing and archiving: Forschungsdaten für Promotionsvorhaben über Repositorien publizieren und archivieren: Eine landesweite Initiative im Rahmen des Projekts bwDataDiss am Beispiel des Karlsruher Instituts für Technologie (KIT)

Nowadays research relies more and more on data to achieve progress in various scientific domains. To understand and to be able to reproduce results, it is essential that the underlying research data is available to scientists - even after a relatively long time. bwDataDiss is an effort to provide infrastructure and services for a very specific group of researchers – namely PhD students – to enable them to store and archive their research data and also to make it available to other researchers

National Ecosystem Assessments in Europe: A Review

National ecosystem assessments form an essential knowledge base for safeguarding biodiversity and ecosystem services. We analyze eight European (sub-)national ecosystem assessments (Portugal, United Kingdom, Spain, Norway, Flanders, Netherlands, Finland, and Germany) and compare their objectives, political context, methods, and operationalization. We observed remarkable differences in breadth of the assessment, methods employed, variety of services considered, policy mandates, and funding mechanisms. Biodiversity and ecosystem services are mainly assessed independently, with biodiversity conceptualized as underpinning services, as a source of conflict with services, or as a service in itself. Recommendations derived from our analysis for future ecosystem assessments include the needs to improve the common evidence base, to advance the mapping of services, to consider international flows of services, and to connect more strongly to policy questions. Although the context specificity of national ecosystem assessments is acknowledged as important, a greater harmonization across assessments could help to better inform common European policies and future pan-regional assessments

Scattering by impurity-induced order parameter ``holes'' in d-wave superconductors

Nonmagnetic impurities in d-wave superconductors cause strong local suppressions of the order parameter. We investigate the observable effects of the scatterigng off such suppressions in bulk samples by treating the order parameter "hole" as a pointlike off-diagonal scatterer treated within a self-consistent t-matrix approximation. Strong scattering potentials lead to a finite-energy spectral feature in the d-wave "impurity band", the observable effects of which include enhanced low-temperature microwave power absorption and a stronger sensitivity of the London penetration depth to disorder than found previously in simpler ``dirty'' d-wave models.Comment: 5 pp. Revtex including 4 postscript figures, submitted to Phys. Rev.

Transport of free surface liquid films and drops by external ratchets and self-ratcheting mechanisms

We discuss the usage of ratchet mechanisms to transport a continuous phase in several micro-fluidic settings. In particular, we study the transport of a dielectric liquid in a heterogeneous ratchet capacitor that is periodically switched on and off. The second system consists of drops on a solid substrate that are transported by different types of harmonic substrate vibrations. We argue that the latter can be seen as a self-ratcheting process and discuss analogies between the employed class of thin film equations and Fokker-Planck equations for transport of discrete objects in a 'particle ratchet'.Comment: 10 pages, 13 figure

Integrating ecosystem services and disservices: insights from plant invasions

There is growing interest in ecosystem disservices, i.e. the negative effects of ecosystems on humans. The focus on disservices has been controversial because of the lack of clarity on how to disentangle ecosystem services and disservices related to human wellbeing. A perspective that considers both services and disservices is needed to inform objective decision-making. We propose a comprehensive typology of ecosystem disservices, and present a framework for integrating ecosystem services and disservices for human wellbeing linked to ecosystem functioning. Our treatment is underpinned by three key assumptions: (1) ecosystem attributes and functions are value-free; (2) the perception of benefits or nuisances are however dependent on societal context, and preferences and actions by societal actors may trigger, enhance or alleviate benefits or nuisances derived from ecosystems; and (3) the notion of disservices must account for the role of human management in assessments of ecosystem values, i.e. the social and technological measures that identify, protect, promote or restore desirable levels of services, and concurrently minimise, mitigate or adapt to disservices. We illustrate our ideas with examples from plant invasions as a complex social-ecological phenomenon

Stripe order and quasiparticle Nernst effect in cuprate superconductors

After a brief review of current ideas on stripe order in cuprate high-temperature superconductors, we discuss the quasiparticle Nernst effect in the cuprates, with focus on its evolution in non-superconducting stripe and related nematic states. In general, we find the Nernst signal to be strongly enhanced by nearby van-Hove singularities and Lifshitz transitions in the band structure, implying that phases with translation symmetry breaking often lead to a large quasiparticle Nernst effect due to the presence of multiple small Fermi pockets. Open orbits may contribute to the Nernst signal as well, but do so in a strongly anisotropic fashion. We discuss our results in the light of recent proposals for a specific Lifshitz transition in underdoped YBCO and make predictions for the doping dependence of the Nernst signal.Comment: 10 pages, 4 figs, article prepared for a special issue of New J Phy