SUMMARYThe original foot-and-mouth disease virus recombination map (Lake, Priston & Slade, I975), which included 35 mutagen-induced ts mutants, has been extended both in detail and size by the mapping of a further 33 ts mutants (9 mutageninduced and 24 spontaneous). The size increase from o'57 % to 3"27 % maximum recombination frequency was principally due to the use of a new standardization technique for recombination frequencies but, in addition, the original map distance was increased by approx. 30 % due to the mapping of new mutations. As in the original map, there was a marked concentration of mutations near the guanidine (gs) locus, i.e. 83 % of the mutants had mutations in the third of the map adjacent to the gs locus.

SUMMARYSixty ts mutants were isolated from the Pacheco strain of type O foot-andmouth disease virus after treatment with either 5-fluorouracil or hydroxylamine. The conditions affecting recombination and assay of the ts + recombinants were standardized. Using two ts mutants resistant to guanidine, three-factor crosses, supported by two-factor crosses, located 34 of the mutations in a linear arrangement. The recombination frequencies between certain pairs of mutations were additive. The guanidine character of the two resistant mutants mapped as a single site mutation and was located near the middle of the map.

The sunbed users interviewed in this study attached considerable significance to tanning, rationalized the risks of sunbed use and expressed their determination to continue using them. The impact of legislation to limit sunbed access may be weakened without requirements to ensure supervision of salons.

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The discourses used to express orientations towards sport, physical education and exercise were explored among 18 students, aged 16-18, at a sixth-form college in England. Results indicate that competitive team sport, and competence in that domain, occupied a privileged position in discourse which operated to polarize orientations towards sport, physical education and exercise. It is argued that an inclusive interpretation of exercise is essential for effective promotion of health-related exercise and, consequently, it is necessary to challenge the privilege afforded to particular modes of participation and to make efforts both to recognize and value alternative activities and meanings.