Secondary instability and tertiary states in rotating plane Couette flow

Recent experimental studies have shown rich transition behaviour in rotating plane Couette flow (RPCF). In this paper we study the transition in supercritical RPCF theoretically by determination of equilibrium and periodic orbit tertiary states via Floquet analysis on secondary Taylor vortex solutions. Two new tertiary states are discovered which we name oscillatory wavy vortex flow (oWVF) and skewed vortex flow (SVF). We present the bifurcation routes and stability properties of these new tertiary states and, in addition, we describe a bifurcation procedure whereby a set of defected wavy twist vortices is approached. Further to this, transition scenarios at flow parameters relevant to experimental works are investigated by computation of the set of stable attractors which exist on a large domain. The physically observed flow states are shown to share features with states in our set of attractor

Mit Bio blüht die Vielfalt – wildtierfreundlicher Biolandbau

Die geplanten Projektaktivitäten in den Modulen 1 bis 3 konnten 2007 gestartet werden: In Teilprojekten 1 und 2 des Moduls 1 „Forschung“ wurden Grundlagen und Methoden erarbeitet: Einerseits wurden die statistischen Kennzahlen zum ökologischen Ausgleich auf Biobetrieben und ÖLN-Betrieben dargestellt und eine vergleichende Analyse auf drei Ebenen (Zonen, Kanton,Bezirk) vorgenommen. Es wurde festgestellt, dass auf Biobetrieben deutlich mehr Ökoausgleichsmassnahmen umgesetzt werden sowie die Zone (Berg-/Talgebiet) und die Region die Akzeptanz für einzelne Massnahmen wesentlich beeinflusst. Andererseits wurden gesamtbetriebliche Beurteilungssysteme (Naturpunktesystem; Naturbilanz Berggebiet)entwickelt. Das in Zusammenarbeit mit der Vogelwarte Sempach entwickelte Punktesystem beurteilt die ökologische Qualität von Landwirtschaftsbetrieben und beschränkt sich auf die Beurteilung von Zuständen und Massnahmen in Nutzflächen und naturnahen Flächen. Zurzeit wird diese favorisierte Methode noch evaluiert und später auf Betrieben getestet. In einem weiteren Teilprojekt (Modellbetriebe Schmetterlinge) wurden wesentliche Grundlagen und Massnahmen zur Förderung von Tagfaltern erarbeitet. Auf zwei Biogrünland-Betrieben im Jura nahe Saignelégier wurde im Sommer 2007 die Tagfalterfauna erfasst und anschliessend betriebsbezogene Massnahmen zum Schutz und Erhalt der Schmetterlinge abgeleitet und mit den Landwirten diskutiert. Der Ansatz wurde sehr gut von den Landwirten aufgenommen und erwies sich auf Grünlandbetrieben als sehr geeignet. Mit insgesamt 33 Arten auf den beiden Betrieben wurde eine relativ hohe Artenzahl an Schmetterlingen festgestellt, darunter vier Arten der Roten Liste. Insgesamt wurden 19 verschiedene Massnahmen im Bereich Wald und Waldrand,Hecken, Grünland entwickelt und vorgeschlagen. Im Modul 2 „Beratung“ wurden in drei weiteren Regionen Modellbetriebe zur Umsetzung wildtierfreundlicher Bewirtschaftung bearbeitet. Sie wurden gesamtbetrieblich beraten: Auf der Basis einer Ist-Analyse wurden mit den Landwirten mögliche Massnahmen diskutiert und festgelegt. Zur Auswahl und Feinsteuerung der Massnahmen wurden Ziel- und Leitarten eingesetzt. In der Region Entlebuch waren es fünf und in der Region Münsingen zwei Betriebe. Im Unterengadin wurden auf vier Betrieben zusätzlich zur gesamtbetrieblichen Beratung drei betriebswirtschaftliche Szenarien (Extensiv - Optimiert – Intensiv) kalkuliert und den Landwirten für die Entscheidungsfindung zur Verfügung gestellt. Die Untersuchung hat gezeigt, dass auf den vier untersuchten Betrieben eine Verbesserung der Ökologie unter Berücksichtigung gesamtbetrieblicher Aspekte möglich war. In vielen Fällen konnten durch ökologische Aufwertungen betriebswirtschaftliche Vorteile erzielt werden (geringerer Arbeitsaufwand, höhere Direktzahlungen verbunden mit geringerem Verkaufserlös). Im Modul 3 „Öffentlichkeitsarbeit“ war in der ersten Phase das Ziel, ein Basissortiment an Informationen für die am Projekt beteiligten Landwirte und die Beratung bereitzustellen. Dazu gehörten die allgemeine Vorstellung des Projektes, die Gestaltung des Logos, die Erstellung des Flyers und die Informationen im Internet. Speziell für die am Projekt beteiligten Landwirte und die Beratung wurden ein Infoblatt mit den Besonderheiten des Projektes sowie ein Infoordner mit Broschüren zu Einzelthemen zusammengestellt. Drei Feldrandtafeln zum Thema Artenvielfalt im Tal- und Berggebiet und Säume wurden erstellt. Sie dienen den Landwirten auf ihren Betrieben zur Information von Laien. Für den Tag der Offenen Tür am FiBL wurde ein Infostand konzipiert,der interessierte Laien angesprochen hatte

Use of organic inputs by arable farmers in six agro-ecological zones across Europe: Drivers and barriers

Soil organic matter (SOM) in agricultural soils builds up via – among others - the use of organic inputs such as straw, compost, farmyard manure or the cultivation of green manures or cover crops. SOM has benefits for long-term soil fertility and can provide ecosystem services. Farmer behaviour is however known to be motivated by a larger number of factors. Using the theory of planned behaviour, we aimed to disentangle these factors. We addressed the following research question: What are currently the main drivers and barriers for arable farmers in Europe to use organic inputs? Our study focuses on six agro-ecological zones in four European countries (Austria, Flanders [Belgium], Italy and the Netherlands) and four practices (straw incorporation, green manure or cover crops, compost and farmyard manure). In a first step, relevant factors were identified for each practice with farmers using 5 to ten semi-structured interviews per agro-ecological zone. In a second step, the relevance of these factors was quantified and they were classified as either drivers or barriers in a large scale farm survey with 1263 farmers. In the semi-structured interviews, 110 factors that influenced farmer decisions to use an organic input were identified. In the larger farm survey, 60% of the factors included were evaluated as drivers, while 40% were evaluated as barriers for the use of organic inputs. Major drivers to use organic inputs were related to the perceived effects on soil quality (such as improved soil structure or reduced erosion) and the positive influence from social referents (such as fellow farmers or agricultural advisors). Major barriers to use organic inputs were financial (increased costs or foregone income) and perceived effects on crop protection (such as increased weeds, pests and diseases, or increased pesticide use). Our study shows that motivating farmers to use organic inputs requires specific guidance on how to adapt cultivation practices to reduce weeds, pests and diseases for specific soil types, weather conditions, and crops. In addition, more research is needed on the long-term financial consequences of using organic inputs

Severity of left ventricular remodeling defines outcomes and response to therapy in heart failure Valsartan heart failure trial (Val-HeFT) echocardiographic data

AbstractObjectivesThe objective of this study was to test the hypothesis that the severity of left ventricular remodeling predicts the response to treatment and outcomes in chronic heart failure.BackgroundReversal of remodeling should produce the most favorable outcome in patients with the most severe remodeling.MethodsIn 5,010 heart failure patients on background therapy and randomized to valsartan and placebo, serial recordings of left ventricular internal diastolic diameter (LVIDd) and ejection fraction (EF) were read at sites that had to meet qualifying standards before participating. Baseline LVIDd and EF were pooled across treatments and retrospectively grouped by quartiles Q1 to Q4, representing best to worst. Kaplan-Meier survival curves were obtained by the log-rank test. Q1 was compared with Q4 for mortality and combined mortality and morbidity (M + M) from Cox regression risk ratios (RRs). Valsartan versus placebo changes from baseline in LVIDd and EF were analyzed by quartiles from analysis of covariance. Valsartan and placebo were compared by RRs for M + M.ResultsSurvival rates were greater in the better quartiles for LVIDd and EF (p < 0.00001). The RR for Q1 versus Q4 in events approached 0.5 for both LVIDd and EF (p < 0.0001). An LVIDd decrease and EF increase were quartile-dependent and greater with valsartan than placebo at virtually all time points. The RR for M + M outcomes favored valsartan in the worse quartiles.ConclusionsStratification by baseline severity of remodeling showed that patients with worse LVIDd and EF are at highest risk for an event, yet appear to gain the most anti-remodeling effect and clinical benefit with valsartan treatment

In situ visualization of large-scale turbulence simulations in Nek5000 with ParaView Catalyst

In situ visualization on high-performance computing systems allows us to analyze simulation results that would otherwise be impossible, given the size of the simulation data sets and offline post-processing execution time. We develop an in situ adaptor for Paraview Catalyst and Nek5000, a massively parallel Fortran and C code for computational fluid dynamics. We perform a strong scalability test up to 2048 cores on KTH’s Beskow Cray XC40 supercomputer and assess in situ visualization’s impact on the Nek5000 performance. In our study case, a high-fidelity simulation of turbulent flow, we observe that in situ operations significantly limit the strong scalability of the code, reducing the relative parallel efficiency to only ≈ 21 % on 2048 cores (the relative efficiency of Nek5000 without in situ operations is ≈ 99 %). Through profiling with Arm MAP, we identified a bottleneck in the image composition step (that uses the Radix-kr algorithm) where a majority of the time is spent on MPI communication. We also identified an imbalance of in situ processing time between rank 0 and all other ranks. In our case, better scaling and load-balancing in the parallel image composition would considerably improve the performance of Nek5000 with in situ capabilities. In general, the result of this study highlights the technical challenges posed by the integration of high-performance simulation codes and data-analysis libraries and their practical use in complex cases, even when efficient algorithms already exist for a certain application scenario

Results from the intercalibration of optical low light calibration sources 2011

Following the 38th Annual European Meeting on Atmospheric Studies by Optical Methods in Siuntio in Finland, an intercalibration workshop for optical low light calibration sources was held in Sodankylä, Finland. The main purpose of this workshop was to provide a comparable scale for absolute measurements of aurora and airglow. All sources brought to the intercalibration workshop were compared to the Fritz Peak reference source using the Lindau Calibration Photometer built by Wilhelm Barke and Hans Lauche in 1984. The results were compared to several earlier intercalibration workshops. It was found that most sources were fairly stable over time, with errors in the range of 5–25%. To further validate the results, two sources were also intercalibrated at UNIS, Longyearbyen, Svalbard. Preliminary analysis indicates agreement with the intercalibration in Sodankylä within about 15–25%

Physics at the e+ e- Linear Collider

A comprehensive review of physics at an e+e- Linear Collider in the energy range of sqrt{s}=92 GeV--3 TeV is presented in view of recent and expected LHC results, experiments from low energy as well as astroparticle physics.The report focuses in particular on Higgs boson, Top quark and electroweak precision physics, but also discusses several models of beyond the Standard Model physics such as Supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analyzed as well.Comment: 179 pages, plots and references updated, version to be published at EPJ

Shower development of particles with momenta from 15 GeV to 150 GeV in the CALICE scintillator-tungsten hadronic calorimeter

We present a study of showers initiated by electrons, pions, kaons, and protons with momenta from 15 GeV to 150 GeV in the highly granular CALICE scintillator-tungsten analogue hadronic calorimeter. The data were recorded at the CERN Super Proton Synchrotron in 2011. The analysis includes measurements of the calorimeter response to each particle type as well as measurements of the energy resolution and studies of the longitudinal and radial shower development for selected particles. The results are compared to Geant4 simulations (version 9.6.p02). In the study of the energy resolution we include previously published data with beam momenta from 1 GeV to 10 GeV recorded at the CERN Proton Synchrotron in 2010.Comment: 35 pages, 21 figures, 8 table

Scientific Committee guidance on appraising and integrating evidence from epidemiological studies for use in EFSA's scientific assessments

EFSA requested its Scientific Committee to prepare a guidance document on appraising and integrating evidence from epidemiological studies for use in EFSA's scientific assessments. The guidance document provides an introduction to epidemiological studies and illustrates the typical biases, which may be present in different epidemiological study designs. It then describes key epidemiological concepts relevant for evidence appraisal. This includes brief explanations for measures of association, exposure assessment, statistical inference, systematic error and effect modification. The guidance then describes the concept of external validity and the principles of appraising epidemiological studies. The customisation of the study appraisal process is explained including tailoring of tools for assessing the risk of bias (RoB). Several examples of appraising experimental and observational studies using a RoB tool are annexed to the document to illustrate the application of the approach. The latter part of this guidance focuses on different steps of evidence integration, first within and then across different streams of evidence. With respect to risk characterisation, the guidance considers how evidence from human epidemiological studies can be used in dose–response modelling with several different options being presented. Finally, the guidance addresses the application of uncertainty factors in risk characterisation when using evidence from human epidemiological studies