Magnetic Bernstein inequalities and spectral inequality on thick sets for the Landau operator

We prove a spectral inequality for the Landau operator. This means that for all $f$ in the spectral subspace corresponding to energies up to $E$, the $L^2$-integral over suitable $S \subset \mathbb{R}^2$ can be lower bounded by an explicit constant times the $L^2$-norm of $f$ itself. We identify the class of all measurable sets $S \subset \mathbb{R}^2$ for which such an inequality can hold, namely so-called thick or relatively dense sets, and deduce an asymptotically optimal expression for the constant in terms of the energy, the magnetic field strength and in terms of parameters determining the thick set $S$. Our proofs rely on so-called magnetic Bernstein inequalities. As a consequence, we obtain the first proof of null-controllability for the magnetic heat equation (with sharp bound on the control cost), and can relax assumptions in existing proofs of Anderson localization in the continuum alloy-type model.Comment: 26 page

The Impact of Non-profit Temping Agencies on Individual Labour Market Success in the West German State of Rhineland-Palatinate

The paper presents an econometric evaluation of the effects of subsidised non-profit temporary employment agencies - a programme of the West German active labour market policy - on individual labour market outcomes. The empirical analysis is based on individual data from files for computer-assisted job brokering in Rhineland-Palatinate. Econometric estimates based on matching methods suggest that the programme generated a statistically significant additional reintegration success of about 13 per centage points. Furthermore within the first four month after leaving the programme, the estimated effect was about half a month additional employment for the participants

Validation of an automated enzyme immunoassay for interleukin-6 for routine clinical use

Serum levels of Interleukin-6 (IL-6), a proinflammatory cytokine, are increased in early stages of inflammatory diseases such as infection and sepsis. Assay systems which permit its measurement within a few hours and as a single measurement have not been reported so far. We therefore evaluated a now commercially available automated method for IL-6 measurement on the Cobas Core(R) immunological analyzer (Roche Diagnostic Systems) which enables single IL-6 measurement within about 1 hour. The automated assay correlates well with an established, manual microtiter plate assay (Biosource GmbH) which uses the same antibodies and reagents (r=0.98). Accuracy of the automated method was established by adding known amounts of IL-6 international reference preparation. Recovery of the international standard was in the range of 92-104%. The automated assay had a precision of singletons below 6% and was linear up to 2800 pg/ml. This automated assay provides a suitable, convenient and time saving method for measurement of IL-6 serum levels in the routine clinical laboratory

Die gemeinnützige Arbeitnehmerüberlassung in Rheinland-Pfalz - eine ökonometrische Analyse des Wiedereingliederungserfolgs

Dieser Beitrag stellt ausgewählte Ergebnisse des vom Zentrum für Europäische Wirtschaftsforschung (ZEW) im Auftrag des IAB und des Ministeriums für Arbeit und Soziales Rheinland-Pfalz bearbeiteten Forschungsprojekts "Arbeitsplatzeffekte gemeinnütziger Arbeitnehmerüberlassungen in Rheinland-Pfalz" vor. Der ökonometrische Vergleich des Wiedereingliederungserfolgs zeigt Unterschiede zwischen Leiharbeitnehmern und Kontrollgruppe auf. In der kurzen Frist (bis zu 5 Monaten nach Ende des Aufenthalts in der Gesellschaft) weisen die Leiharbeitnehmer ein im Vergleich zur Kontrollgruppe um bis zu 13 Prozentpunkte besseres Wiedereingliederungsergebnis auf. Die Arbeit zeigt, daß die in der Evaluation von Programmen zur Wiedereingliederung spezifischer Arbeitsmarktgruppen noch vergleichsweise wenig verbreitete Matching- Methode in Verbindung mit der hohen Datenqualität, die durch die präzise Aufbereitung der Erwerbsgeschichte in der coArb zustande gekommen ist, eine geeignete Methode zur Abschätzung von Maßnahmeeffekten darstellt

Coherent photon coincidence spectroscopy of single quantum systems

Non-equilibrium photon correlations of coherently excited single quantum systems can reveal their internal quantum dynamics and provide spectroscopic access. Here we propose and discuss the fundamentals of a coherent photon coincidence spectroscopy based on the application of laser pulses with variable delay and the detection of an time-averaged two-photon coincidence rate. For demonstration, two simple but important cases, i.e., an exciton - biexciton in a quantum dot and two coupled quantum emitters, are investigated based on quantum dynamics simulations demonstrating that this nonlinear spectroscopy reveals information specific to the particular single quantum system

Die gemeinnützige Arbeitnehmerüberlassung in Rheinland-Pfalz : eine ökonometrische Analyse des Wiedereingliederungserfolgs (Non-profit hiring-out of labour in Rhineland-Palatinate : an econometric analysis of the reintegration success)

"This article presents selected results from the research project 'Effects on jobs of non-profit-making temporary employment businesses in Rhineland-Palatinate', which was carried out by the Centre for European Economic Research on the instructions of the IAB and the Rhineland-Palatinate Ministry for Labour and Social Affairs (IAB project 10-483 A). The primary objective of the project is to assess empirically whether unemployed individuals who have worked for a temporary employment business show a better rate of success in reintegrating into the primary labour market than unemployed individuals who have not worked for such a business. Data material from two sources forms the basis of this assessment. Firstly the eight temporary employment businesses examined were asked, both in writing and in qualitative interviews, about their characteristic features, the socio-economic background of all of their temporary wor-kers as well as about their detailed temporary employment history and subsequent destinations. Secondly the Federal Employment Services made available copies from the files on computer-assisted job placement ('coArb') which were drawn up at the employment offices concerned. On the basis of the coArb data, econometric methods (matching) are used to select a control group of unemployed individuals who have not worked for a temporary employment business. This control group is intended to be as similar as possible to the temporary worker group with regard to their socio-economic structure and labour market history. Thus it is taken into account among other things that compared with the unemployed as a whole, the temporary workers are younger, more frequently male and include a larger proportion of foreigners, resettlers of Ger-man origin and people from the former German Democratic Republic. Furthermore, in forming the control group it is taken into consideration that temporary workers have a lower than average level of education and training and show unsettled employment histories with frequent changes between spells of unemployment and employment. The econometric comparison of the reintegration success shows differences between temporary workers and the control group. In the short period (up to 5 months following the end of the time spent with the temporary employment business) the temporary workers show a reintegration result that is up to 13 percentage points better than that of the control group. For example, two months after leaving the temporary employment business 27.4 percent of the temporary workers are working in the primary labour market, whereas in the control group of people who did not take part in such a scheme the figure is only 14 percent. The result withstands statistical tests and can therefore be classified as significant. In view of the data situation, however, it is not possible to make a statement concerning the medium to long-term success. The report shows that the matching method, which is comparatively still not particularly wide-spread in the evaluation of programmes aimed at the reintegration of specific labour market groups, in association with the high quality of data, which was achieved by means of the pre-cise processing of the employment histories in the coArb, constitutes a suitable method for assessing the effects of employment and training measures." (Author's abstract, IAB-Doku) ((en))gemeinnützige Arbeitnehmerüberlassung, berufliche Reintegration, Leiharbeitnehmer, Arbeitslose, Rheinland-Pfalz, Bundesrepublik Deutschland

Die gemeinnützige Arbeitnehmerüberlassung in Rheinland-Pfalz: Eine ökonometrische Analyse des Wiedereingliederungserfolgs

Dieser Beitrag stellt ausgewahlte Ergebnisse des vom Zentrum für Europäische Wirtschaftsforschung (ZEW) im Auftrag des IAB und des Ministeriums für Arbeit und Soziales Rheinland-Pfalz bearbeiteten Forschungsprojekts "Arbeitsplatzeffekte gemeinnütziger Arbeitnehmerüberlassungen in Rheinland-Pfalz" vor. Der ökonometrische Vergleich des Wiedereingliederungserfolgs zeigt Unterschiede zwischen Leiharbeitnehmern und Kontrollgruppe auf. In der kurzen Frist (bis zu 5 Monaten nach Ende des Aufenthalts in der Gesellschaft) weisen die Leiharbeitnehmer ein im Vergleich zur Kontrollgruppe um bis zu 13 Prozentpunkte besseres Wiedereingliederungsergebnis auf. Die Arbeit zeigt, dass die in der Evaluation von Programmen zur Wiedereingliederung spezifischer Arbeitsmarktgruppen noch vergleichsweise wenig verbreitete Matching- Methode in Verbindung mit der hohen Datenqualität, die durch die präzise Aufbereitung der Erwerbsgeschichte in der coArb zustande gekommen ist, eine geeignete Methode zur Abschätzung von Maßnahmeeffekten darstellt. --Arbeitnehmerüberlassung,Ökonometrie,aktive Arbeitsmarktpolitik,Matching