A Monopolist in Public Transport: Undersupply or Oversupply?

A monopolist in public transport may oversupply frequency relative to the social optimum, as van Reeven (2008) demonstrates with homogeneous consumers. This result generalizes for heterogeneous consumers who know the timetable. Whether a monopolist oversupplies or undersupplies frequency depends on the degree of consumers’ heterogeneity as reflected in the distribution of consumers’ reservation prices. Oversupply is likely to occur when this distribution is peaked, and undersupply is likely to occur when this distribution is rather flat. In particular, monopoly production results in the oversupply of frequency when consumers’ reservation prices are concentrated around the entry costs of the private car, being the main alternative to public transport

VLA radio continuum observations of a new sample of high redshift radio galaxies

We present new deep multi-frequency radio-polarimetric images of a sample of high redshift radio galaxies (HzRGs), having redshift between 1.7 and 4.1. The radio data at 4.7 and 8.2 GHz were taken with the Very Large Array in the A configuration and provide a highest angular resolution of 0.2''. Maps of total intensity, radio spectral index, radio polarization and internal magnetic field are presented for each source. The morphology of most objects is that of standard FRII double radio sources, but several contain multiple hot-spots in one or both lobes. Compared to similar samples of HzRGs previously imaged, there is a higher fraction (29%) of compact steep spectrum sources (i.e. sources with a projected linear size less than 20 kpc). Radio cores are identified in about half of the sample and tend to have relatively steep spectra (alpha < -1). Polarization is detected in all but 4 sources, with typical polarization at 8.2 GHz of around 10-20%. The Faraday rotation can be measured in most of the radio galaxies: the observed rotation measure (RM) of 8 radio sources exceeds 100 rad m^{-2} in at least one of the lobes, with large gradients between the two lobes. We find no dependence of Faraday rotation with other properties of the radio sources. If the origin of the Faraday rotation is local to the sources, as we believe, then the intrinsic RM is more than a 1000 rad m^{-2}. Because low redshift radio galaxies residing at the center of clusters usually show extreme RMs, we suggest that the high-z large RM sources also lie in very dense environments. Finally, we find that the fraction of powerful radio galaxies with extreme Faraday rotation increases with redshift, as would be expected if their average environment tends to become denser with decreasing cosmic epoch.Comment: Accepted for publication in A&A Supplemen

Gaia on-board metrology: basic angle and best focus

The Gaia payload ensures maximum passive stability using a single material, SiC, for most of its elements. Dedicated metrology instruments are, however, required to carry out two functions: monitoring the basic angle and refocusing the telescope. Two interferometers fed by the same laser are used to measure the basic angle changes at the level of $\mu$as (prad, micropixel), which is the highest level ever achieved in space. Two Shack-Hartmann wavefront sensors, combined with an ad-hoc analysis of the scientific data are used to define and reach the overall best-focus. In this contribution, the systems, data analysis, procedures and performance achieved during commissioning are presentedComment: 18 pages, 14 figures. To appear in SPIE proceedings 9143-30. Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wav

Selected liver grafts from donation after circulatory death can be safely used for retransplantation – a multicenter retrospective study

Due to the growing number of liver transplantations (LTs), there is an increasing number of patients requiring retransplantation (reLT). Data on the use of grafts from extended criteria donors (ECD), especially donation after circulatory death (DCD), for reLT are lacking. We aimed to assess the outcome of patients undergoing reLT using a DCD graft in the Netherlands between 2001 and July 2018. Propensity score matching was used to match each DCD-reLT with three DBD-reLT cases. Primary outcomes were patient and graft survival. Secondary outcome was the incidence of biliary complications, especially nonanastomotic strictures (NAS). 21 DCD-reLT were compared with 63 matched DBD-reLTs. Donors in the DCD-reLT group had a significantly lower BMI (22.4 vs. 24.7 kg/m2, P-value = 0.02). Comparison of recipient demographics and ischemia times yielded no significant differences. Patient and graft survival rates were comparable between the two groups. However, the occurrence of nonanastomotic strictures after DCD-reLT was significantly higher (38.1% vs. 12.7%, P-value = 0.02). ReLT with DCD grafts does not result in inferior patient and graft survival compared with DBD grafts in selected patients. Therefore, DCD liver grafts should not routinely be declined for patients awaiting reLT

Randomized Trial of Ciclosporin with 2-h Monitoring vs. Tacrolimus with Trough Monitoring in Liver Transplantation:DELTA Study

Background and Aims: Previous trials comparing cyclosporine and tacrolimus after liver transplantation (LT) showed conflicting results. Most used trough monitoring for cyclosporine (C0), leading to less accurate dosing than with 2-h monitoring (C2). Only one larger trial compared C2 with tacrolimus based on trough level (T0) after LT, with similar treated biopsy-proven acute rejection (tBPAR) and graft loss, while a smaller trial had less tBPAR with C2 compared to T0. Therefore, it is still unclear which calcineurin inhibitor is preferred after LT. We aimed to demonstrate superior efficacy (tBPAR), tolerability, and safety of C2 or T0 after first LT. Methods: Patients after first LT were randomized to C2 or T0. tBPAR, patient-and graft survival, safety and tolerability were the main endpoints, with analysis by Fisher test, Kaplan–Meier survival analysis and log-rank test. Results: In intention-to treat analysis 84 patients on C2 and 85 on T0 were included. Cumulative incidence of tBPAR C2 vs. T0 was 17.7% vs. 8.4% at 3 months (p=0.104), and 21.9% vs. 9.7% at 6 and 12 months (p=0.049). One-year cumulative mortality C2 vs. T0 was 15.5% vs. 5.9% (p=0.049) and graft loss 23.8% vs. 9.4% (p=0.015). Serum triglyceride and LDL-cholesterol was lower with T0 than with C2. Incidence of diarrhea in T0 vs, C2 was 64% vs. 31% (p≤0.001), with no other differences in safety and tolerability. Conclusions: In the first year after LT immunosuppression with T0 leads to less tBPAR and better patient-/re-transplant-free survival as compared to C2.</p

Donor diabetes mellitus is a risk factor for diminished outcome after liver transplantation:a nationwide retrospective cohort study

BACKGROUND: With the growing incidence of diabetes mellitus (DM), an increasing number of organ donors with DM can be expected. We sought to investigate the association between donor DM with early post-transplant outcomes. METHODS: From a national cohort of adult liver transplant recipients (1996-2016), all recipients transplanted with a liver from a DM donor (n=69) were matched 1:2 with recipients of livers from non-DM donors (n=138). The primary end-point included early post-transplant outcome, such as the incidence of primary non-function (PNF), hepatic artery thrombosis (HAT), and 90-day graft survival. Cox regression analysis was used to analyze the impact of donor DM on graft failure. RESULTS: PNF was observed in 5.8% of grafts from DM donors versus 2.9% of non-DM donor grafts (p=0.31). Recipients of grafts derived from DM donors had a higher incidence of HAT (8.7% vs. 2.2%, p=0.03) and decreased 90-day graft survival (88.4% [70.9-91.1] vs. 96.4% [89.6-97.8], p=0.03) compared to recipients of grafts from non-DM donors. The adjusted hazard ratio for donor DM on graft survival was 2.21 (1.08-4.53, p=0.03). CONCLUSION: Donor DM is associated with diminished outcome early after liver transplantation. The increased incidence of HAT after transplantation of livers from DM donors requires further research

Multi-store Competition: Market Segmentation or Interlacing

This paper develops a model for multi-store competition between firms. Using the fact that different firms have different outlets and produce horizontally differentiated goods, we obtain a pure strategy equilibrium where firms choose a different location for each outlet and firms' locations are interlaced. The location decisions of multi-store firms are completely independent of each other. Firms choose locations that minimize transportation costs of consumers. Moreover, generically, the subgame perfect equilibrium is unique and when the firms have an equal number of outlets, prices are independent of the number of outlets