Numerical simulation of the three-dimensional structure and dynamics of the non-magnetic solar chromosphere

Three-dimensional numerical simulations with CO5BOLD, a new radiation hydrodynamics code, result in a dynamic, thermally bifurcated model of the non-magnetic chromosphere of the quiet Sun. The 3-D model includes the middle and low chromosphere, the photosphere, and the top of the convection zone, where acoustic waves are excited by convective motions. While the waves propagate upwards, they steepen into shocks, dissipate, and deposit their mechanical energy as heat in the chromosphere. Our numerical simulations show for the first time a complex 3-D structure of the chromospheric layers, formed by the interaction of shock waves. Horizontal temperature cross-sections of the model chromosphere exhibit a network of hot filaments and enclosed cool regions. The horizontal pattern evolves on short time-scales of the order of typically 20 - 25 seconds, and has spatial scales comparable to those of the underlying granulation. The resulting thermal bifurcation, i.e., the co-existence of cold and hot regions, provides temperatures high enough to produce the observed chromospheric UV emission and -- at the same time -- temperatures cold enough to allow the formation of molecules (e.g., carbon monoxide). Our 3-D model corroborates the finding by Carlsson & Stein (1994) that the chromospheric temperature rise of semi-empirical models does not necessarily imply an increase in the average gas temperature but can be explained by the presence of substantial spatial and temporal temperature inhomogeneities.Comment: 18 pages, 13 figures, accepted by Astronomy & Astrophysics (30/10/03

Rübsen (Brassica rapa var. silvestris) als Fangpflanze zur Kontrolle von Schadinsekten in Winterraps

Previous studies have shown that most of the specialized rape pests prefer turnip rape over oilseed rape. In our studies two trap crop strategies were tested under field conditions in central Germany. In the first trial a turnip rape (Brassica rapa var. silvestris) strip was sown along the edges of the oilseed rape (Brassica napus) main crop. In the second trial a seed mixture of 95% oilseed rape and 5% turnip rape was sown and was compared to oilseed rape in pure crop. In both experiments the turnip rape trap crop was more attractive to cabbage stem flea beetle (Psylliodes chrysocephala) and pollen beetle (Meligethes aeneus) than the oilseed rape. Neither the border strip nor the intercropping was able to reduce the level of infestation of the oilseed rape crop and the damage caused by these pests. Both strategies were inapplicable to increase the grain yield of oilseed rape

Solar abundances and 3D model atmospheres

We present solar photospheric abundances for 12 elements from optical and near-infrared spectroscopy. The abundance analysis was conducted employing 3D hydrodynamical (CO5BOLD) as well as standard 1D hydrostatic model atmospheres. We compare our results to others with emphasis on discrepancies and still lingering problems, in particular exemplified by the pivotal abundance of oxygen. We argue that the thermal structure of the lower solar photosphere is very well represented by our 3D model. We obtain an excellent match of the observed center-to-limb variation of the line-blanketed continuum intensity, also at wavelengths shortward of the Balmer jump.Comment: Contributed paper, to be published in the proceedings of IAU Symposium 265, eds. K. Cunha, M. Spite, and B. Barbuy, Cambridge University Press (CUP). 2 figures, 4 page

Structural Barriers In The Context Of Opiate Substitution Treatment In Germany - A Survey Among Physicians In Primary Care

Background Opiate substitution treatment (OST) is the most widely used treatment for opioid dependence in Germany with substantial long-term benefits for the patient and for society. Due to lessened restrictive admission criteria, the number of registered OST patients in Germany has increased continuously in the recent years, whereas the number of physicians providing OST has remained constant. Previous data already indicated a deteriorating situation in the availability or quality of OST delivered and that structural barriers impede physicians in actively providing OST. The present survey among a sample of primary care physicians in Germany aimed to identify and assess potential structural barriers for the provision of health care in the context of OST. Methods An anonymous written questionnaire was sent out to a sample of 2,332 physicians across Germany providing OST. Physicians contacted were identified through databases of the Federal State Chambers of Physicians and/or of the Federal Associations of Statutory Health Insurance Physicians. Data obtained were analysed descriptively. Results The response rate was 25,5% and the majority of 596 physicians sampled viewed substantial problems in terms of the regulatory framework of OST care in the German context. Furthermore, financial remuneration, insufficient qualification, as well as inadequate interdisciplinary cooperation in the treatment of comorbidities of opiate substituted patients were regarded as problematic. The number of physicians providing OST in Germany is expected to substantially decrease in the near future. Conclusion Despite less restrictive admission criteria for OST in Germany, the legal regulation framework for OST is still a limiting factor through raising concerns on the provider and consumer side to be unable to adhere to the strict rules. To avoid future shortages in the provision of OST care on the system level in Germany, revisions to the legal framework seem to be necessary. In regards to adequate care for drug use-related infectious diseases and psychiatric comorbidities commonly found in opiate substituted patients, efforts are required to improve professional qualifications of physicians providing OST as well as respective interdisciplinary collaboration

Stickstoff- und Schwefelversorgung von Rapsbeständen im Ökologischen Landbau

In this study results of 3 experimental years, 4 locations (2009-2011) and additionally 12 fields in northern and eastern Germany (only in 2011) are presented with regard to the nitrogen and sulphur status of oil seed rape. The nitrogen and sulphur level was often not sufficient, so that the fertilisation regimes have to be optimised

Schädlingsregulierung im ökologischen Winterrapsanbau

Die Versuche unter norddeutschen Praxisbedingungen sowie die Ergebnisse der Feldversuche belegen eine durchgehend höhere Attraktivität des Rübsens gegenüber Raps für den Rapsglanzkäfer. Damit werden die Beobachtungen aus der Praxis zunächst bestätigt. Durch den direkten Vergleich von Rapsfeldern mit und ohne Rübsen-Randstreifen sowie von Raps/Rübsen-Mischsaaten mit Rapsreinsaat in Praxis- sowie Feldversuchen war es möglich, den Erfolg dieser Maßnahme in seiner gesamten Wirkungsvielfalt zu untersuchen. Es hat sich gezeigt, dass entgegen den Erwartungen weder der Schädlingsbesatz noch der Schaden im Rapskernbestand durch den Rübsen-Fangstreifen wesentlich reduziert werden konnte. Ebenso erbrachte die flächige Mischsaat von Raps mit Rübsen keine deutliche Entlastung für die Schadensausprägung in der Hauptkomponente Raps. Die Wirkungsgrade der Fangpflanzen blieben damit deutlich hinter den Erwartungen der Praxis zurück und die Mehraufwendungen überstiegen den erwarteten Nutzen. Zusammenfassend muss festgestellt werden, dass der alleinige Fangpflanzenanbau als Randstreifen um den Rapsbestand herum oder als Mischsaat der Praxis als alleiniges Konzept für die Schädlingsregulierung nicht empfohlen werden kann und sogar das ökonomische Verlustrisiko erhöht. Diese Erkenntnis ist für die Praxis sehr wertvoll, da die Anwendung der Fangpflanzen zum Teil empfohlen wird und der Landwirt durch die stärkere Bindung der Rapsglanzkäfer an den Rübsen vermeintlich glaubt, erfolgreich den Schädlingsbefall zu regulieren und damit die Erträge zu erhöhen. Die praxisnahen Versuche haben noch einmal die Schwierigkeiten des ökologischen Rapsanbaus in seiner gesamten Breite aufgezeigt. Ausgehend von dem hohen Nährstoffbedarf reichen die Probleme bei der Unkraut- und Schädlingsregulierung bis zur Ernte, bei der zusätzlich durch ungleichmäßige Abreife und geringe Schotenfestigkeit, hohe Ernteverluste entstehen können. Die Untersuchungen zur Wirkung naturstofflicher Pflanzenschutzmittel konnten einen Hinweis darauf geben, welche Wirkstoffe eine wirksame Kontrolle der Rapsglanzkäfer ermöglichen. Dazu zählen Spinosad, ein Fermentationsprodukt aus einem Bodenmikroorganismus sowie Gesteinsmehle, die allerdings mehrfach angewendet werden müssen und deshalb nur für die Teilflächenbehandlung in Frage kommen. Während in der Schweiz Spinosad in einem Pflanzenschutzmittel im Raps zugelassen ist, fehlt eine derartige Zulassung bisher in Deutschland und darf nicht angewendet werden

Model projections on the impact of HCV treatment in the prevention of HCV transmission among people who inject drugs in Europe"

Prevention of hepatitis C virus (HCV) transmission among people who inject drugs (PWID) is critical for eliminating HCV in Europe. We estimated the impact of current and scaled-up HCV treatment with and without scaling up opioid substitution therapy (OST) and needle and syringe programmes (NSPs) across Europe over the next 10 years. We collected data on PWID HCV treatment rates, PWID prevalence, HCV prevalence, OST, and NSP coverage from 11 European settings. We parameterised an HCV transmission model to setting-specific data that project chronic HCV prevalence and incidence among PWID. At baseline, chronic HCV prevalence varied from <25% (Slovenia/Czech Republic) to >55% (Finland/Sweden), and <2% (Amsterdam/Hamburg/Norway/Denmark/Sweden) to 5% (Slovenia/Czech Republic) of chronically infected PWID were treated annually. The current treatment rates using new direct-acting antivirals (DAAs) may achieve observable reductions in chronic prevalence (38-63%) in 10 years in Czech Republic, Slovenia, and Amsterdam. Doubling the HCV treatment rates will reduce prevalence in other sites (12-24%; Belgium/Denmark/Hamburg/Norway/Scotland), but is unlikely to reduce prevalence in Sweden and Finland. Scaling-up OST and NSP to 80% coverage with current treatment rates using DAAs could achieve observable reductions in HCV prevalence (18-79%) in all sites. Using DAAs, Slovenia and Amsterdam are projected to reduce incidence to 2 per 100 person years or less in 10 years. Moderate to substantial increases in the current treatment rates are required to achieve the same impact elsewhere, from 1.4 to 3 times (Czech Republic and France), 5-17 times (France, Scotland, Hamburg, Norway, Denmark, Belgium, and Sweden), to 200 times (Finland). Scaling-up OST and NSP coverage to 80% in all sites reduces treatment scale-up needed by 20-80%. The scale-up of HCV treatment and other interventions is needed in most settings to minimise HCV transmission among PWID in Europe. Measuring the amount of HCV in the population of PWID is uncertain. To reduce HCV infection to minimal levels in Europe will require scale-up of both HCV treatment and other interventions that reduce injecting risk (especially OST and provision of sterile injecting equipment

Measuring self-regulation in everyday life: reliability and validity of smartphone-based experiments in alcohol use disorder

Self-regulation, the ability to guide behavior according to one’s goals, plays an integral role in understanding loss of control over unwanted behaviors, for example in alcohol use disorder (AUD). Yet, experimental tasks that measure processes underlying self-regulation are not easy to deploy in contexts where such behaviors usually occur, namely outside the laboratory, and in clinical populations such as people with AUD. Moreover, lab-based tasks have been criticized for poor test–retest reliability and lack of construct validity. Smartphones can be used to deploy tasks in the field, but often require shorter versions of tasks, which may further decrease reliability. Here, we show that combining smartphone-based tasks with joint hierarchical modeling of longitudinal data can overcome at least some of these shortcomings. We test four short smartphone-based tasks outside the laboratory in a large sample (N = 488) of participants with AUD. Although task measures indeed have low reliability when data are analyzed traditionally by modeling each session separately, joint modeling of longitudinal data increases reliability to good and oftentimes excellent levels. We next test the measures’ construct validity and show that extracted latent factors are indeed in line with theoretical accounts of cognitive control and decision-making. Finally, we demonstrate that a resulting cognitive control factor relates to a real-life measure of drinking behavior and yields stronger correlations than single measures based on traditional analyses. Our findings demonstrate how short, smartphone-based task measures, when analyzed with joint hierarchical modeling and latent factor analysis, can overcome frequently reported shortcomings of experimental tasks

Measuring self-regulation in everyday life: Reliability and validity of smartphone-based experiments in alcohol use disorder

Self-regulation, the ability to guide behavior according to one's goals, plays an integral role in understanding loss of control over unwanted behaviors, for example in alcohol use disorder (AUD). Yet, experimental tasks that measure processes underlying self-regulation are not easy to deploy in contexts where such behaviors usually occur, namely outside the laboratory, and in clinical populations such as people with AUD. Moreover, lab-based tasks have been criticized for poor test-retest reliability and lack of construct validity. Smartphones can be used to deploy tasks in the field, but often require shorter versions of tasks, which may further decrease reliability. Here, we show that combining smartphone-based tasks with joint hierarchical modeling of longitudinal data can overcome at least some of these shortcomings. We test four short smartphone-based tasks outside the laboratory in a large sample (N = 488) of participants with AUD. Although task measures indeed have low reliability when data are analyzed traditionally by modeling each session separately, joint modeling of longitudinal data increases reliability to good and oftentimes excellent levels. We next test the measures' construct validity and show that extracted latent factors are indeed in line with theoretical accounts of cognitive control and decision-making. Finally, we demonstrate that a resulting cognitive control factor relates to a real-life measure of drinking behavior and yields stronger correlations than single measures based on traditional analyses. Our findings demonstrate how short, smartphone-based task measures, when analyzed with joint hierarchical modeling and latent factor analysis, can overcome frequently reported shortcomings of experimental tasks