Interviews and adverse selection

Interviewing in professional labor markets is a costly process for firms. Moreover, poor screening can have a persistent negative impact on firms bottom lines and candidates careers. In a simple dynamic model where firms can pay a cost to interview applicants who have private information about their own ability, potentially large inefficiencies arise from information-based unemployment, where able workers are rejected by firms because of their lack of offers in previous interviews. This effect may make the market less efficient than random matching. We show that the first best can be achieved using either a mechanism with transfers or one without transfers.

Long-run selection and the work ethic

That individuals contribute in social dilemma interactions even when contributing is costly is a well-established observation in the experimental literature. Since a contributor is always strictly worse off than a non-contributor the question is raised if an intrinsic motivation to contribute can survive in an evolutionary setting. Using recent results on deterministic approximation of stochastic evolutionary dynamics we give conditions for equilibria with a positive number of contributors to be selected in the long run.

Transcription factors link mouse WAP-T mammary tumors with human breast cancer.

Mouse models are important tools to decipher the molecular mechanisms of mammary carcinogenesis and to mimic the respective human disease. Despite sharing common phenotypic and genetic features, the proper translation of murine models to human breast cancer remains a challenging task. In a previous study we showed that in the SV40 transgenic WAP-T mice an active Met-pathway and epithelial-mesenchymal characteristics distinguish low- and high-grade mammary carcinoma. To assign these murine tumors to corresponding human tumors we here incorporated the analysis of expression of transcription factor (TF) coding genes and show that thereby a more accurate interspecies translation can be achieved. We describe a novel cross-species translation procedure and demonstrate that expression of unsupervised selected TFs, such as ELF5, HOXA5 and TFCP2L1, can clearly distinguish between the human molecular breast cancer subtypes-or as, for example, expression of TFAP2B between yet unclassified subgroups. By integrating different levels of information like histology, gene set enrichment, expression of differentiation markers and TFs we conclude that tumors in WAP-T mice exhibit similarities to both, human basal-like and non-basal-like subtypes. We furthermore suggest that the low- and high-grade WAP-T tumor phenotypes might arise from distinct cells of tumor origin. Our results underscore the importance of TFs as common cross-species denominators in the regulatory networks underlying mammary carcinogenesis.

Keisarileikkaus : gynekologian ja obstetriikan historiaa Helsingin yliopiston kirjastossa

Hindrik Strandberg

Long-range transport of Saharan dust to northern Europe: The 11-16 October 2001 outbreak observed with EARLINET

The spread of mineral particles over southwestern, western, and central Europeresulting from a strong Saharan dust outbreak in October 2001 was observed at10 stations of the European Aerosol Research Lidar Network (EARLINET). For the firsttime, an optically dense desert dust plume over Europe was characterized coherentlywith high vertical resolution on a continental scale. The main layer was located abovethe boundary layer (above 1-km height above sea level (asl)) up to 3–5-km height, andtraces of dust particles reached heights of 7–8 km. The particle optical depth typicallyranged from 0.1 to 0.5 above 1-km height asl at the wavelength of 532 nm, andmaximum values close to 0.8 were found over northern Germany. The lidar observationsare in qualitative agreement with values of optical depth derived from Total OzoneMapping Spectrometer (TOMS) data. Ten-day backward trajectories clearly indicated theSahara as the source region of the particles and revealed that the dust layer observed,e.g., over Belsk, Poland, crossed the EARLINET site Aberystwyth, UK, and southernScandinavia 24–48 hours before. Lidar-derived particle depolarization ratios,backscatter- and extinction-related A ° ngstro¨m exponents, and extinction-to-backscatterratios mainly ranged from 15 to 25%, 0.5 to 0.5, and 40–80 sr, respectively, within thelofted dust plumes. A few atmospheric model calculations are presented showing the dustconcentration over Europe. The simulations were found to be consistent with thenetwork observations.

Executive Order, July 15, 1953

Otto Weber is appointed to Colonel on Staff of the Commander-in-Chief

A randomized, double blind, placebo-controlled trial of pioglitazone in combination with riluzole in amyotrophic lateral sclerosis.

BACKGROUND: Pioglitazone, an oral anti-diabetic that stimulates the PPAR-gamma transcription factor, increased survival of mice with amyotrophic lateral sclerosis (ALS). METHODS/PRINCIPAL FINDINGS: We performed a phase II, double blind, multicentre, placebo controlled trial of pioglitazone in ALS patients under riluzole. 219 patients were randomly assigned to receive 45 mg/day of pioglitazone or placebo (one: one allocation ratio). The primary endpoint was survival. Secondary endpoints included incidence of non-invasive ventilation and tracheotomy, and slopes of ALS-FRS, slow vital capacity, and quality of life as assessed using EUROQoL EQ-5D. The study was conducted under a two-stage group sequential test, allowing to stop for futility or superiority after interim analysis. Shortly after interim analysis, 30 patients under pioglitazone and 24 patients under placebo had died. The trial was stopped for futility; the hazard ratio for primary endpoint was 1.21 (95% CI: 0.71-2.07, p = 0.48). Secondary endpoints were not modified by pioglitazone treatment. Pioglitazone was well tolerated. CONCLUSION/SIGNIFICANCE: Pioglitazone has no beneficial effects on the survival of ALS patients as add-on therapy to riluzole. TRIAL REGISTRATION: Clinicaltrials.gov NCT00690118.