South Parks Road, Oxford OX1 3QYStructural investigation of the products obtained by microbiological hydroxylation of substrates in the androstane, pregnane, and mstrane series has involved examining the l H n.m.r. spectra of 344 steroids, 243 of them being new compounds. Mild oxidation of the products gives polyketones in which the positions of the oxo-groups are characterised by the chemical and solvent shifts of the 18-H and 19-H signals. This information is supplemented by the chemical shifts of the products' 18-H and 19-H signals, and by the positions and form of their )CH-OH resonances : the latter are especially useful in establishing the configurations of the hydroxy-groups.FOR the past five years we have been studying the hydroxylation of mono-and di-oxygenated steroids with a range of micro-0rganisrns.l The intention was to vary the positions of the oxygen substituents around the steroid nucleus in a systematic manner: it was -gate, ibid., 1969, 463. hoped that the use of relatively simple substrates would facilitate interpret at ion of the microbiological behaviour. A considerable body of results has accrued from examining monoketones, keto-alcohols, and diketones derived from handrostane, 5a-pregnane, and 5a-cestrane ; a series of papers describing the work will be submitted shortly to this Journal. The preparation of substrates and related chemical studies are being recorded in a separate series2

We conduct a detailed case-study of the interstellar shell near the high-mass X-ray binary, Cygnus X-1. We present new WIYN optical spectroscopic and Chandra X-ray observations of this region, which we compare with detailed MAPPINGS III shock models, to investigate the outflow powering the shell. Our analysis places improved, physically motivated constraints on the nature of the shockwave and the interstellar medium (ISM) it is plowing through. We find that the shock is traveling at less than a few hundred km s −1 through a low-density ISM (< 5 cm −3 ). We calculate a robust, 3σ upper limit to the total, time-averaged power needed to drive the shockwave and inflate the bubble, < 2×10 38 erg s −1 . We then review possible origins of the shockwave. We find that a supernova origin to the shockwave is unlikely and that the black hole jet and/or O-star wind can both be central drivers of the shockwave. We conclude that the source of the Cygnus X-1 shockwave is far from solved.

This investigation into the compositions of Minoan and Mycenaean pottery fabrics was carried out in Oxford at the Research Laboratory for Archaeology and the History of Art by permission of the Director, Dr. E. T. Hall. Mrs. E. E. Richards, co-author of this report, was in charge of the investigation, latterly with the assistance of Mrs. A. Millett. The potential importance of the work undertaken was first suggested by Mr. M. S. F. Hood, then Director of the British School at Athens. Mr. Hood has maintained lively interest in the investigation, and has made many valuable suggestions about the course it should take, as well as providing much of the sherd material. In this connexion we are greatly indebted to Dr. J. Papadimitriou, Director-General of Antiquities in Greece, for granting the necessary export permits. We are also grateful to Mr. M. R. Popham, for scraping selected sherds in the Herakleion Museum and in the Stratigraphical Museum at Knossos, and to Dr. N. Platon, then Ephor of Antiquities in Crete, for allowing this to be done. Sherds from Thebes in the University Museum, Reading, were loaned by Mrs. A. N. Ure; the Rev. Dr. A. J. Arkell provided a set of Mycenaean sherds from Tell el Amarna from the collections in University College, London. Fragments from Rhodes were given by the Department of Greek and Roman Antiquities in the British Museum through the kindness of Mr. D. E. L. Haynes and Mr. R. A. Higgins. Other sherds were provided from the reserve collection in the Ashmolean Museum. The sherds tested in the course of the investigation are now housed in the Ashmolean, with the exception of the group from Thebes (Reading).

No abstract

Convenient preparations have been developed for a series of steroidal mono-olefins free from oxygenated substituents: this Series includes representatives of all but one of the possible endocyclic olefins. The infrared, nuclear magnetic resonance, and ultraviolet spectra of the compounds were examined with particular attention to the relative power and scope of the different techniques in structural diagnosis.