Asteroseismology of binary stars and a compilation of core overshoot and rotational frequency values of OB stars

After a brief introduction into the asteroseismic modelling of stars, we provide a compilation of the current seismic estimates of the core overshooting parameter and of the rotational frequency of single and binary massive stars. These important stellar parameters have meanwhile become available for eleven OB-type stars, among which three spectroscopic pulsating binaries and one magnetic pulsator. We highlight the potential of ongoing and future analyses of eclipsing binary pulsators as essential laboraties to test stellar structure and evolution models of single and binary stars.Comment: Proceedingspaper, 8 pages, 3 figures, 1 table, to appear in "Setting a New Standard in the Analysis of Binary Stars", Eds K. Pavlovski, A. Tkachenko, and G. Torres, EAS Publications Serie

Massive Star Asteroseismology in Action

After highlighting the principle and power of asteroseismology for stellar physics, we briefly emphasize some recent progress in this research for various types of stars. We give an overview of high-precision high duty-cycle space photometry of OB-type stars. Further, we update the overview of seismic estimates of stellar parameters of OB dwarfs, with specific emphasis on convective core overshoot. We discuss connections between pulsational, rotational, and magnetic variability of massive stars and end with future prospects for asteroseismology of evolved OB stars.Comment: Invited review paper to appear in Proc. IAU307: New windows on massive stars: asteroseismology, interferometry, and spectropolarimetry, Editors: G. Meynet, C. Georgy, J.H. Groh & Ph. Stee, 9 pages, 2 figure

Optimal Use of Labor Market Policies: The Role of Job Search Assistance

This paper studies the role of job search assistance programs in optimal welfare-to-work programs. The analysis is based on a framework, that allows for endogenous choice of benefit types and levels, wage taxes or subsidies, and activation measures such as monitoring and job search assistance for each period of unemployment in a dynamic environment with negative duration dependence in the exit rates to employment and potential depreciation in reemployment wages. We show that the main role of job search assistance is to delay or prevent situations in which it is no longer optimal to incentivize the worker to provide positive search effort. It is used to restore or maintain some minimum exit rate to employment which increases with the cost-effectiveness of job search assistance. We also find that in line with existing policies, these programs should mainly be used at the beginning of unemployment and for short durations. However, contrary to existing schemes, they should be exclusively targeted at unemployed workers with low initial exit rates to employment. For all other workers, they should only be used if they fail to find a job within reasonable time despite high expected initial exit rates.job search, optimal unemployment insurance, welfare-to-work policies, recursive contracts

Why do Europeans Work so Little?

Market work per person is roughly 10 percent higher in the U.S. than in Sweden. However, if we include the work carried out in home production, the total amount of work only differs by 1 percent. I set up a model with home production, and show that differences in policy - mainly taxes – can account for the discrepancy in labor supply between Sweden and the U.S. Moreover, even though the elasticity of labor supply is rather low for individual households, labor taxes are estimated to be associated with considerable output losses. I also show that policy can account for the falling trend in market work in Sweden since 1960. The largest reduction occurs from 1960 until around 1980, both in the model and the data. After the early 1980s, the trends for both taxes and actual hours worked are basically flat. This is also true for hours worked in the model.Labor supply; Taxes; Home production

The Welfare Gains of Improving Risk Sharing in Social Security

This paper shows that improved intergenerational risk sharing in social security may imply very large welfare gains, amounting to up to 15 percent of the per-period consumption relative to the current U.S. consumption. Improved risk sharing raises welfare through a direct effect, i.e., by correcting an initially inefficient allocation of risk, and through a general equilibrium (GE) effect. The GE effect is due to the fact that the allocation of risk in the pay-as-you-go system influences the demand for capital. As a result, with an efficient risk sharing arrangement, the crowding out effect associated with an unfunded system can actually be completely eliminated. Efficient risk sharing in social security implies highly volatile and pro-cyclical benefits, i.e., that retirees' exposure to productivity risk is increased. Consequently, a policy involving completely safe benefits will unambiguously be welfare reducing.Social security; Risk sharing

Effects of team task structure on team climate for innovation and team outcomes

In this cross-sectional study we analyzed, whether team climate for innovation mediates the relationship between team task structure and innovative behavior, job satisfaction, affective organizational commitment, and work stress. 310 employees in 20 work teams of an automotive company participated in this study. 10 teams had been changed from a restrictive to a more self-regulating team model by providing task variety, autonomy, team-specific goals, and feedback in order to increase team effectiveness. Data support the supposed causal chain, although only with respect to team innovative behavior all required effects were statistically significant. Longitudinal designs and larger samples are needed to prove the assumed causal relationships, but results indicate that implementing self-regulating teams might be an effective strategy for improving innovative behavior and thus team and company effectiveness.innovation; behavior; working teams

Working with the CHILDES tools : transcription, coding and analysis

The Child Language Data Exchange System (CHILDES) consists of Codes for the Human Analysis of Transcripts (CHAT), Computerized Language Analysis (CLAN), and a database. There is also an online manual which includes the CHILDES bibliography, the database, and the CHAT conventions as well as the CLAN instructions. The first three parts of this paper concern the CHAT format of transcription, grammatical coding, and analyzing transcripts by using the CLAN programs. The fourth part shows examples of transcribed and coded data

On the seismic modelling of rotating B-type pulsators in the traditional approximation

The CoRoT and Kepler data revolutionised our view on stellar pulsation. For massive stars, the space data revealed the simultaneous presence of low-amplitude low-order modes and dominant high-order gravity modes in several B-type pulsators. The interpretation of such a rich set of detected oscillations requires new tools. We present computations of oscillations for B-type pulsators taking into account the effects of the Coriolis force in the so-called traditional approximation. We discuss the limitations of classical frequency matching to tune these stars seismically and show that the predictive power is limited in the case of high-order gravity mode pulsators, except if numerous modes of consecutive radial order can be identified.Comment: 8 pages, 4 figures. Paper submitted for publication in the Proceedings of the 61st Fujihara Seminar: Progress in solar/stellar physics with helio- and asteroseismology to appear in ASP Conference Serie