Model analysis of circadian rhythms in mouse epidermal basal cell proliferation

Computer simulations were made of circadian variations in six observed cell kinetic variables in the basal cell layer of hairless mouse epidermis. Different mathematical models were used and simultaneously fitted to all observed variables by an automatic method. The analysis shows that the origin of the circadian variations in cell kinetics in hairless mouse epidermis is not in the G₁ phase or at the $\text{G}{}_1\text{S}$ transition alone as concluded from other studies, but must result from circadian variations in the duration of S and G₂ phases. The results show that the data are compatible with the existence of circadian variations in the G₁- and M-phase durations, although such variations, unlike the S and G₂ variations, was not necessary to obtain a good fit of the model to the data. The results also indicate that the data are compatible with the existence of transient resting states of limited duration in S- and G₂-phases.     

The publication and typification of Sir James Edward Smith's lichens in English Botany

A total of 391 lichens were written up in Smith's English Botany , of which 57 were new. All were illustrated by James Sowerby. The copyright dates are given, which should be accepted as those of publication. They range from 1793 until 1814, and paper watermarks show that reprintings occurred until c . 1818. The locations of the type specimens are given, many of which are part of the BM Botany Library, mounted together with Sowerby's original English Botany drawings, and therefore often overlooked. Their current taxonomic position is evaluated. Only 11 of the 57 new lichens have been placed in synonymy, which indicates that Smith was an excellent lichen taxonomist. Caloplaca borreri J.R.Laundon is a new name for Lepraria ochracea Turner & Borrer ex Sm., whilst Herteliana gagei (Sm.) J.R.Laundon is a new combination with priority over H. taylorii P.James, and Trapelia glebulosa (Sm.) J.R.Laundon replaces T. involuta (Taylor) Hertel. Species requiring author corrections are Caloplaca cerina (Hedw.) Th.Fr., Enterographa elaborata (Leight.) Coppins & P.James, Lecidella pulveracea (Flörke ex Th.Fr.) P.Syd., and Parmelia borreri Turner. Lichen daedaleus Sm. pre-dates Lecidea sorediata Ach. by 4 years, but has been proposed for rejection in order to retain the established name Pyxine sorediata (Ach.) Mont. Eight names remain undetermined, chiefly fungi in Spiloma.   © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 147 , 483–499.