Thyroid hormone receptor a isoforms generated by alternative splicing differentially activate myosin HC gene transcription Seigo lzumo & Vijak Mahdavi Nature 334, 539-542 (1988). IN the typing of the derived amino-acid sequence of rTRa 1 and rTRa2 cDNAs, the sequence for amino acids 401-410 were inadvertently swapped between the two isoforms. The correct sequence reads: FLEVFEDQEV for rTRa 1 and QLLGMHVVQG for rTRa2.

Ground investigations for the A303 Stonehenge Tunnels revealed a unique and complex Chalk geology including the presence of the thickest (>20m thick), and previously unknown phosphatic chalks in England, partly filling fault controlled erosional channels. The use of natural gamma-ray borehole logs to determine the presence and thickness of the phosphatic deposits is of particular value and combined with the lithostratigraphy, macrofossil and nannofossil biostratigraphy from cores has, for the first time, accurately constrained the Coniacian to Santonian age and the lenticular geometry of such deposits. Four phosphatic chalk events between 88.5-86.5 Ma are recognised associated with synsedimentary faulting. We suggest a causal link between tectonics, subsidence and channel-formation, phosphatisation events, pulses of oceanic upwelling on a frequency of about 0.5 million years to mantle-controlled plate tectonic episodes. The implications of this geology for construction of the A303 and the archaeology of the area are discussed. Key stratigraphical control Borehole R11 nannofossil analyses and age of the phosphatic chalks Borehole R11, because it contained the most horizons of phosphatic chalks, separated by 'normal' chalks, was chosen as the standard for further detailed stratigraphical analyses using

The role of the analytical chemist in the development of the extraterrestrial impact theory for mass extinctions at the terminal Cretaceous Period is reviewed. High iridium concentrations in Cretaceous/Tertiary boundary clays have been linked to a terrestrial impact from an iridium-rich asteroid or large meteorite some 65 million years ago. Other evidence in favour of the occurrence of such an impact has been provided by the detection of shocked quartz grains originating from impact and of amorphous carbon particles similar to soot, derived presumably from wordwide wildfires at the terminal Cretaceous. Further evidence provided by the analytical chemist involves the determination of isotopic ratios such as 144Nd/143Nd, 187Os/186Os, and 87Sr/86Sr. Countervailing arguments put forward by the gradualist school (mainly palaeontological) as opposed to the catastrophists (mainly chemists and geochemists) are also presented and discussed.