Exploiting fitness distance correlation of set covering problems

The set covering problem is an NP-hard combinatorial optimization problem that arises in applications ranging from crew scheduling in airlines to driver scheduling in public mass transport. In this paper we analyze search space characteristics of a widely used set of benchmark instances through an analysis of the fitness-distance correlation. This analysis shows that there exist several classes of set covering instances that have a largely different behavior. For instances with high fitness distance correlation, we propose new ways of generating core problems and analyze the performance of algorithms exploiting these core problems.Set covering, iterated local search

Effects of upstream hydropower operation and oligotrophication on the light regime of a turbid peri-alpine lake

Abstract.: Anthropogenic activities in catchments can alter the light regimes in downstream natural waters, affecting light attenuation and the perceived optical properties of the waters. We analyzed the effects of upstream hydropower operation and oligotrophication on light attenuation and reflectance in Lake Brienz (Switzerland). For this purpose, we reconstructed its light regime for the pre-dam condition and for periods of 4-fold increased primary productivity, based on direct observations of light and beam attenuation as well as concentrations of optically active compounds, especially observed and simulated mineral particle concentrations. Based on our assessment, light attenuation before the construction of upstream dams was double the current value during summer and nearly half in winter. This result is consistent with pre-dam measurements of Secchi depths in the early 1920s. Using a simple optical model, a significant increase in reflectance since the 1970s was estimated, assuming a 4-fold decrease of optical active organic compounds within the lake. As reflectance is perceived by human eyes as turbidity, this may explain subjective reports by local residents of increasing turbidity in recent year

Bestimmung des Regulierungsbedarfs aus ökonomischer Sicht: Angemessenheit und Folgen einer funktionalen oder strukturellen Trennung von Swisscom.

The study analyzes the regulatory need of a functional or structural separation of the Swiss incumbent Swisscom.Separation, Access, Telecommunications

Isolation of an Osmium(III) Hydrido Complex

Synthesis and characterization of [OsH(PNP)(bipy)]+ (PNP=N(CHCHPtBu2)2) are reported, as the second osmium(III) hydrido complex next to [OsH(en)2(py)]2+. While the osmium(II) precursor, [OsH(PNP)(bipy)], exhibits two reversible oxidations in the cyclic voltammogram, the product from 2‐electron oxidation could not be isolated due to rapid decay. Thermochemical examinations attribute the stability of the osmium(III) hydride to both thermodynamic and kinetic reasons. In contrast, the high estimated acidity of [OsH(PNP)(bipy)]2+ presumably leads to rapid decay.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Fonds der Chemischen Industrie http://dx.doi.org/10.13039/100018992Peer Reviewe

Effects of alpine hydropower operations on primary production in a downstream lake

Abstract.: During the past century, the construction of hydropower dams in the watershed of Lake Brienz has significantly altered the dynamics of turbidity, which has important implications for lake productivity. To assess these effects, we measured in situ carbon assimilation rates and ambient light intensities over 18months. Based on experimental data, a numerical model was developed to assess gross primary production under present light conditions and those under a hypothetical case without upstream dams. Light conditions for the hypothetical ‘no-dam' situation were estimated from pre-dam Secchi depths and simulated ‘no-dam' particle concentrations. Current gross primary production is low (~66 gC m−2 yr−1), and could increase ~44% if the lake was less turbid. Disregarding nutrient retention in reservoirs, we estimate gross primary production would be ~35% lower in summer and ~23% higher in winter in the absence of reservoirs. The annual primary production (~58 gC m−2 yr−1) would decrease ~12% compared to the current primary production with dams. According to model calculations, hydropower operations have significantly altered the seasonal dynamics, but have little effect on annual primary production in Lake Brien

Combining conductive atomic force microscopy with electrically detected magnetic resonance

We present the design and implementation of a scanning probe microscope, which combines electrically detected magnetic resonance (EDMR) and (photo-)conductive atomic force microscopy ((p)cAFM). The integration of a 3-loop 2-gap X-band microwave resonator into an AFM allows the use of conductive AFM tips as a movable contact for EDMR experiments. The optical readout of the AFM cantilever is based on an infrared laser to avoid disturbances of current measurements by absorption of straylight of the detection laser. Using amorphous silicon thin film samples with varying defect densities, the capability to detect a spatial EDMR contrast is demonstrated. Resonant current changes as low as 20 fA can be detected, allowing the method to realize a spin sensitivity of 8×106spins/√Hz at room temperature

Examination of Protonation-Induced Dinitrogen Splitting by in Situ EXAFS Spectroscopy

The splitting of dinitrogen into nitride complexes emerged as a key reaction for nitrogen fixation strategies at ambient conditions. However, the impact of auxiliary ligands or accessible spin states on the thermodynamics and kinetics of N-N cleavage is yet to be examined in detail. We recently reported N-N bond splitting of a {Mo(μ2:η1:η1-N2)Mo}-complex upon protonation of the diphosphinoamide auxiliary ligands. The reactivity was associated with a low-spin to high-spin transition that was induced by the protonation reaction in the coordination periphery, mainly based on computational results. Here, this proposal is evaluated by an XAS study of a series of linearly N2 bridged Mo pincer complexes. Structural characterization of the transient protonation product by EXAFS spectroscopy confirms the proposed spin transition prior to N-N bond cleavage

„Mild-behavioral-impairment“-Checkliste

Hintergrund: Das Syndrom einer leichten Verhaltensbeeinträchtigung („mild behavioral impairment syndrome“, MBI) ist definiert durch das Auftreten anhaltender neuropsychiatrischer Symptome im Alter. Die Mild-behavioral-impairment-Checkliste (MBI-C) dient der Erfassung von persistierenden neuropsychiatrischen Symptomen, welche die Präsenz des MBI definieren. Ziel: Erarbeitung einer deutschsprachigen Version der MBI-C und Beurteilung der klinischen Anwendbarkeit. Material undMethoden: ImAustausch mit dem federführenden Autor der englischen Originalversionwurde eine deutsche Version erstellt. Die Praktikabilität der Anwendung wurde im Rahmen einer Anwendbarkeitsstudie an einer Kohorte von 21 stationären alterspsychiatrischen Patienten überprüft. Dabei wurden die Compliance der Patienten, die Verständlichkeit, der Zeitaufwand, das Vorgehen bei der Auswertung und die Unterschiede zwischen den Angaben der Patienten und der Angehörigen beurteilt. Ergebnisse: Die erstellte Übersetzung der MBI-C gilt als offizielle deutsche Version und kann auf https://mbitest.org heruntergeladen werden. Alle Patienten beantworteten alle 34 Fragen vollständig, die Verständlichkeit zeigte sich als sehr gut, der durchschnittliche Zeitaufwand lag bei 16min. Es zeigten sich z. T. bedeutsame Unterschiede zwischen den Angaben der Patienten und der Angehörigen. Diskussion: Das MBI kann bei einem Teil der Personen mit neurodegenerativer demenzieller Erkrankung das ansonsten präsymptomatische Stadium markieren. Die MBI-C könnte somit bei der Früherkennung von neurodegenerativen Demenzen helfen. Diese Hypothese kann mithilfe der hier präsentierten sprachlich lokalisierten Version der MBI-C auch im deutschsprachigen Raumzukünftig überprüft werden

Scenarios for European agricultural policymaking in the era of digitalisation

CONTEXT Digitalisation affects the agri-food sector and its governance. However, what digitalisation of the sector will imply for future agricultural policymaking remains unclear. OBJECTIVE The objective of the study is to develop and evaluate explorative scenarios of digitalisation in the agri-food sector of Europe that are explicitly relevant to agricultural policy. The study aims to provide guidance for strategic development of agricultural policy to address the potentials, uncertainties and unknowns arising with digitalisation of the sector. METHODS We combine a Delphi study and a participatory scenario workshop to develop and evaluate plausible explorative scenarios of digitalisation of Europe's agri-food sector. For all scenarios we identify gaps in achieving a range of important European agricultural policy goals, drawing on the Delphi study and desk-based analysis. Subsequently we deduce strategies to address these agricultural policy gaps. RESULTS AND CONCLUSIONS Four scenarios of digitalisation of the agri-food sector were developed for Europe in 2030. They comprise of 1) digitalisation of the sector following current directions at current rates as a baseline scenario, 2) strong digitalisation of a regulatory government, 3) use of autonomous farming technology and 4) digitalised food business. These explorative scenarios entail various gaps in achieving European agricultural policy goals. Our findings suggest that the baseline scenario needs strategies to ramp up technological and institutional infrastructure for digitalisation. The other scenarios need strategies to prevent risks, e.g., of technological failures or undesired social impacts. They also need strategies to cater for special cases and diversity, e.g., of ecosystems and farming practices. Across the scenarios, it seems useful to increase digital competencies of the stakeholders. SIGNIFICANCE The study is the first that derives implications for policy strategies from explorative scenarios of future digitalisation of agricultural systems that target gaps in achieving agricultural policy goals. The combination of developing and analysing scenarios generated findings that are of significance to policymaking stakeholders and researchers alike, who all need to address the uncertainties arising with future digitalisation of the agri-food sector