of dihydropyrazines (DHPs) such as 2,3-dihydro-5,6-dimethylpyrazine (Me-DHP), which causes DNA strand breakage in the plasmid pBR322. We showed that DHPs inhibit growth and cause mutagenesis in Escherichia coli and that Me-DHP is cytotoxic and genotoxic in E. coli due to the production of radical species in the presence of Cu . Phenyl substituted dihydropyrazines (Ph-DHPs) have much higher DNA ...

A GOOD DEAL is now known about the incidence of plague in this country during the early modern period, but attempts to probe the wider impact of these epidemics on the general history of the era have been rare. This is curious, for plague occupies a prominent position in tlhe historiography of the later middle ages; but while the disease remained a major factor in the lives of Englishmen for ne...

[3] D. J. Bryden. A didactic introduction to arithmetic, sir charles cotterell's 'instrument for arithmeticke' of 1667. " Note, this book contains a flawed conclusion as to the priority of the invention of the sliderule. See [9]. [9] Florian Cajori. On the history of gunter's scale and the slide rule during the seventeenth century.

An ongoing search for Zeeman splitting in the 1667 MHz OH megamaser emission from luminous star-forming galaxies has yielded numerous detections. These results, in addition to being the first extragalactic measurement of the Zeeman effect in an emission line, suggest that OH megamasers are excellent extragalactic magnetometers. We review the progress of our survey and discuss future observations.

REFERENCES Wallis G. B., One-Dimensional Two-Phase Flow. McGraw-Hill, New York 1969. Foscolo P. U. and Gibilaro L. G., Chem. Engng Sci. 1984 39 1667. Gibilaro L. G., Di Felice R., Waldram S. P. and Foscolo P. Il., Chem. Engng Sci. 1985 4

OH megamasers (OHMs) emit primarily in the main lines at 1667 and 1665 MHz, and differ from their Galactic counterparts due to their immense luminosities, large linewidths and 1667/1665 MHz flux ratios, which are always greater than one. We find that these maser properties result from strong 53 μm radiative pumping combined with line overlap effects caused by turbulent linewidths ∼ 20 km s; pum...