A bryozoan buildup from the Lower Carboniferous of North Wales

A carbonate buildup dominated by trepostome Bryozoa is described from Dinantian (Asbian) strata near Llandudno in North Wales. A three-phase ecological succession is recognised within the buildup: (i) a basal diverse community with fenestrate, ramose, encrusting trepostome and cystoporate bryozoans in a mud rich wackestone; (ii) a bulk facies, dominated by encrusting and foliaceous, trepostome bryozoans in a fine packstone, and (iii) a thin capping phase, dominated by unilaminar, encrusting trepostome bryozoans in a slightly coarser lithology, including skeletal debris derived from the mound top and possible flanking beds. The buildup probably had topographic relief and developed in a shallow marine environment. The internal tripartite zonation reflects the growth of the structure into a shallower, higher energy regime, with the capping beds being deposited just below wave base. The buildup developed to the north of St. George's Land, on a carbonate shelf edge bordering the deeper basinal facies of the Irish Sea Basin. Dinantian, Asbian, buildup, trepostome Bryozoa, Foraminifera, corals, calcareous algae, Carboniferous, North Wales .     

Efficacy of a training programme designed to teach cervical smear screeners to identify ocular surface squamous neoplasia using conjunctival impression cytology

Efficacy of a training programme designed to teach cervical smear screeners to identify ocular surface squamous neoplasia using conjunctival impression cytology
Ocular surface squamous neoplasia (OSSN) is a recently proposed term introduced to encompass both intraepithelial neoplasia and invasive squamous cell carcinoma of the conjunctiva and cornea. A teaching programme incorporating a manual, slide sets, and an evaluation test was developed. The aim was to teach experienced cervical smear screeners to evaluate ocular surface specimens collected by conjunctival impression cytology, with a minimum of individual tuition. The use of the manual was well accepted and half of the original six candidates were able to master the new skill adequately within 8 h. It was considered that the differences between the cytology of OSSN and the equivalent lesions of the uterine cervix are sufficient to prevent some experienced screeners acquiring these skills rapidly.     

Restriction mapping of genomic DNA from five cyanophages infecting the heterocystous cyanobacteria Nostoc and Anabaena

The positions of the cleavage sites of several restriction endonucleases were mapped in DNA isolated from the cyanophages A-1L, A-4L, AN-10, AN-13 and AN-23, which were replicated in Anabaena PCC 7120. Similarities within the maps show AN-13 and AN-23 to be closely related strains. A-1L and AN-10 also appear to be related, but show more divergence. The maps of A-1L and AN-10 are circular, apparently as the result of circular permutation of sequences. The maps of the other cyanophages are linear.     

Nonamplifying alleles at microsatellite loci: a caution for parentage and population studies

While genotyping wild red deer (Cervus elaphus) at microsatellite loci for paternity assignment, we found three loci (MAP65, BOVIRBP and CelJP23) with segregating nonamplifying alleles. Nonamplifying alleles were detected through mismatches between known mother-offspring pairs and by significant deviations from Hardy-Weinberg equilibria. In a wide range of molecular ecology applications, and especially in parentage assignment, the possible existence of undetectable alleles must be taken into account; this may be particularly important for microsatellite data.