A massive binary black-hole system in OJ 287 and a test of general relativity

Tests of Einstein's general theory of relativity have mostly been carried out in weak gravitational fields where the space-time curvature effects are first-order deviations from Newton's theory. Binary pulsars provide a means of probing the strong gravitational field around a neutron star, but strong-field effects may be best tested in systems containing black holes. Here we report such a test in a close binary system of two candidate black holes in the quasar OJ 287. This quasar shows quasi-periodic optical outbursts at 12-year intervals, with two outburst peaks per interval. The latest outburst occurred in September 2007, within a day of the time predicted by the binary black-hole model and general relativity. The observations confirm the binary nature of the system and also provide evidence for the loss of orbital energy in agreement (within 10 per cent) with the emission of gravitational waves from the system. In the absence of gravitational wave emission the outburst would have happened 20 days later.     

The histamine and heparin content of the rat's mesenterial mast cells regenerating after application of compound 48/80

Zusammenfassung Der Histamin- und Heparingehalt in Mastzellen, die nach totaler Zerstörung mit Histaminliberator 48/80 regenerieren, wird untersucht. Die Ergebnisse zeigen, dass während des Regenerationsprozesses die Anzahl der Mastzellen, in denen sich das Histamin mit Reineckesalzlösung anfärbt, kleiner ist, als die Anzahl der Mastzellen, die mit Toluidinblau darzustellen sind.