Scalable Spatio-Temporal Smoothing via Hierarchical Sparse Cholesky Decomposition

We propose an approximation to the forward-filter-backward-sampler (FFBS) algorithm for large-scale spatio-temporal smoothing. FFBS is commonly used in Bayesian statistics when working with linear Gaussian state-space models, but it requires inverting covariance matrices which have the size of the latent state vector. The computational burden associated with this operation effectively prohibits its applications in high-dimensional settings. We propose a scalable spatio-temporal FFBS approach based on the hierarchical Vecchia approximation of Gaussian processes, which has been previously successfully used in spatial statistics. On simulated and real data, our approach outperformed a low-rank FFBS approximation

Ecosystem services in European protected areas: Ambiguity in the views of scientists and managers?

Protected Areas are a key component of nature conservation. They can play an important role in counterbalancing the impacts of ecosystem degradation. For an optimal protection of a Protected Area it is essential to account for the variables underlying the major Ecosystem Services an area delivers, and the threats upon them. Here we show that the perception of these important variables differs markedly between scientists and managers of Protected Areas in mountains and transitional waters. Scientists emphasise variables of abiotic and biotic nature, whereas managers highlight socio-economic, cultural and anthropogenic variables. This indicates fundamental differences in perception. To be able to better protect an area it would be advisable to bring the perception of scientists and managers closer together. Intensified and harmonised communication across disciplinary and professional boundaries will be needed to implement and improve Ecosystem Service oriented management strategies in current and future Protected Areas.This study was done in the frame of the EcoPotential project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 641762

The Seventh Data Release of the Sloan Digital Sky Survey

This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor correction

Public Sector Perspectives 2024: Empfehlungen für den öffentlichen Sektor

Nachhaltigkeit und Digitalisierung sind die zwei Megatrends des 21. Jahrhunderts. Das Institut Public Sector Transformation widmet sich diesen beiden Trends in zahlreichen Forschungsprojekten, die wir mit Praxispartnern aus Verwaltung, Wirtschaft und Zivilgesellschaft umsetzen. Der vorliegende Bericht fasst unsere Erfahrungen in komprimierter Form zusammen. Konkrete Erkenntnisse, zukünftige Entwicklungen und Empfehlungen zeigen Perspektiven auf, wohin die Reise im Jahr 2024 gehen wird und was es dabei zu beachten gilt. Diese gliedern sich in sechs zentralen Themencluster: Nachhaltigkeit & Gesellschaft, öffentliche Beschaffung, Smart Government, Daten, Public Sector IT und künstliche Intelligenz. Die «Public Sector Perspectives» sind eine Momentaufnahme, ein Innehalten in dieser herausfordernden Zeit. Wir zeigen, was uns beschäftigt, was wir wissen, was wir ahnen und wie wir uns die Zukunft des öffentlichen Sektors vorstellen. In 27 Kapiteln haben über 30 Forschende des Instituts Public Sector Transformation ihren aktuellen Wissensstand sowie ihre Handlungsempfehlungen aufgezeichnet

Mountains and climate change: A global concern

Mountains are among the regions most affected by climate change. The implications of climate change will reach far beyond mountain areas, as the contributions in the present publication prepared for the Conference of the Parties to the United Nations Framework Convention on Climate Change (COP 20) in Lima 2014 show. Themes discussed are water, glaciers and permafrost, hazards, biodiversity, food security and economy. The case studies included show that concrete adaptive action has been taken in many mountain areas of the world. The publication concludes with a series of recommendations for sustainable mountain development in the face of climate change