The Garching-Bonn Deep Survey (GaBoDS) Wide-Field-Imaging Reduction Pipeline

We introduce our publicly available Wide-Field-Imaging reduction pipeline THELI. The procedures applied for the efficient pre-reduction and astrometric calibration are presented. A special emphasis is put on the methods applied to the photometric calibration. As a test case the reduction of optical data from the ESO Deep Public Survey including the WFI-GOODS data is described. The end-products of this project are now available via the ESO archive Advanced Data Products section.Comment: 6 pages, 3 figures, proceedings of ESO Calibration Workshop 200

Nurturing #TeacherVoice: Why Educators’ Online Presence Matters to Educational Equity

Educatio

Cryogenic filter method produces super-pure helium and helium isotopes

Helium is purified when cooled in a low pressure environment until it becomes superfluid. The liquid helium is then filtered through iron oxide particles. Heating, cooling and filtering processes continue until the purified liquid helium is heated to a gas

Helium refining by superfluidity Patent

Helium refining by superfluidit

Supercold technique duplicates magnetic field in second superconductor

A superconductor cylinder, charged with a high magnetic field, can be used to create a similar field in a larger cylinder. The uncharged cylinder is precooled, lowered into a helium dewar system, and fitted around the cylinder with the magnetic field. Magnetic flux lines pass through the two cylinders

Calibration update of the COMBO-17 CDFS catalogue

We present an update to the photometric calibration of the COMBO-17 catalogue on the Extended Chandra Deep Field South, which is now consistent with the GaBoDS and MUSYC catalogues. As a result, photometric redshifts become slightly more accurate, with <0.01 rms and little bias in the delta_z/(1+z) of galaxies with R<21 and of QSOs with R<24. With increasing photon noise the rms of galaxies reaches 0.02 for R<23 and 0.035 at R~23.5. Consequences for the rest-frame colours of galaxies at z<1 are discussed.Comment: A&A research note, resubmitted 02 Oct 2008, 4 pages in print forma

Too many to fail? Inter-enterprise arrears in transition economies

In advanced market economies, the use of trade credits is an important way of short-term financing and generally considered as being part of normal business practice. Some transition economies, however, have experienced a rapid accumulation of trade credits which have led to interlocking webs of arrears and collective bailouts by the government. In this paper, firm-level data is used to test whether trade credits are just part of normal business practice comparable to more advanced market-economies or whether trade credits represent a systematic phenomena supporting soft budget constraints of firms in transition. The results suggest that trade credits are not just normal business practice but that they can have negative spill-over effects on other firms by worsening their financial situation. We conclude that the problem of interlocking effects is more pronounced in countries with less developed institutions, low financial intermediation and, overall, no credible commitment to market economic reforms.inter-enterprise arrears, soft budget constraints, transition economies