Notes: A partial recording system, suitable for use in caries incremental studies, was developed from first principles using data from 330 11- to 14-year-old English schoolchildren. This system was shown to be rapid, accurate and highly efficient when the results were compared with full-mouth statistics. Comparisons were also made with five published caries partial recording methods, using 2- and 3-year incremental data from a recent clinical trial. The results have been calculated both excluding and including precavitation lesions, as well as for three separate surface types (fissure, free smooth surface and approximal). Three methods of expressing “relative efficiency” are compared. The need for partial recording systems to be maximally efficient is discussed. The results confirm that many partial recording techniques are accurate, efficient and capable of considerably reducing examination time.

Notes: The effect of different adjuvants on the foliar uptake of difenzoquat methyl sulfate and sodium 2,4-D was studied in wild oat and field bean plants growing under controlled environmental conditions. The 14C-herbicides were applied to leaves as c. 0–2-μl droplets, usually containing 0.5 g 1−1 active ingredient, plus adjuvants in the range 0.05–5 g 1−1. The addition of non-ionic polyoxyethylene surfactants to solutions of both herbicides could induce considerable foliar uptake. Aliphatic C13C13 alcohol surfactants generally improved uptake more than nonylphenol surfactants when used at equivalent concentrations and ethylene oxide (EO) contents. The surfactant threshold for enhancement of difenzoquat uptake in wild oat was very low (0.05 g 1−1), whilst that in field bean was much higher (〉0.5 g 1−1). For 2,4-D, surfactants at 〉0–5 g 1−1 were needed to produce substantial increases in its uptake into both species. Although surfactants of low EO content (5–6) were less efficient at promoting difenzoquat uptake than those of higher EO content (10–20), particularly in wild oat, there was little dependence on surfactant EO content for enhancement of 2,4-D uptake. Adjuvants with humectant properties also promoted penetration of difenzoquat, but less so than alcohol or nonylphenol surfactants. For formulations of both 14C-herbicides translocation was directly related to the quantity of radiolabel that had penetrated the leaf tissue. Effets de la formulation avec différents adjuvants sur l'absorption foliaire du difenzoquat et du 2,4-D: modeles experimentaux sur la folle avoine et le haricot L'influence de differents adjuvants sur l'absorption foliaire du difenzoquat methyl sulfate et du 2,4 D sodium a eétéétudiée chez la folle avoine et le haricot, cultivés sous des conditions environnementales contrôlées. Les herbicides marquees au 14C ont ete appliquées aux feuilles sous forme de gouttelettes de 0,2 μl contenant 0,5 g 1−1 de matière active, avec en plus des adjuvants de 0,05 à 5 g −1. L'adjonction de surfactants polyoxyethylénes non ioniques aux solutions des deux herbicides pourrait induire un absorption foliaire importante. Les surfactants d'alcools aliphatiques C13/C15 ont généralement augmenté la pénétration mieux que les surfactants de type nonylphénol utilises à une concentration équivalente et que les oxydes d'éthylènes (EO). Le seuil de surfactant pour l'amélioration de l'absorption de difenzoquat sur folle avoine était très bas (0,05 g 1−1) tandis que sur haricot, il était beaucoup plus éievé (〉 0,5 g 1−1). Pour le 2,4 D, des surfactants à une dose de 〉0,5 g 1−1 sont nécessaires pour produire une amelioration de son absorption chez les deux espéces. Bien que les surfactants à faible teneur en EO (5–6) fussent moins efficace pour favoriser l'absorption du difenzoquat que ceux a forte teneur (10–20), spécialement pour la folle avoine, il y avait une petite dépendance sur la teneur en EO pour l'amélioration de l'absorption du 2,4 D. Les adjuvants avec des propriétés d'humectation ont favorisé la pénétration du difenzoquat, mais moins que les surfactants alcool ou nonylphenol. Pour les formulations des deux herbicides marqués au 14C, le transport était directement reliéà la quantité de molécule marquée ayant pénétrée dans le tissu foliaire. Wirkung verschiedener Netzmittel auf die Blattaufnahme von Difenzoquat und 2,4-D am Beispiel von Flug-Hafer und Ackerbohne Der Einfluß verschiedener Zusatzstoffe auf die Blattaufnahme von Difenzoquat und 2,4-D-Na- Salz wurde an Flug-Hafer- und Ackerbohnen-Pflanzen unter kontroUierten Bedingungen untersucht. Die 14C-Herbizide wurden auf die Blatter mit etwa 0,2 μl großen Tröpfchen einer Lösung mit 0,5 g 1−1 AS und 0,05 bis 5 g 1−1 des Zusatzstoffs ausgebracht. Durch Zugabe von nichtionischen Polyoxyethylen-Netzmittein zu den Lösungen der beiden Herbizide konnte die Blattaufnahme erheblich gesteigert werden. Aliphatische C13C15-Alkohol-Netzmittel förderten die Aufnahme mehr als Nonylphenol-Netzmittel, wenn sie mit equivalenten Konzentrationen und Ethylenoxid-(EO)Gehalten ausgebracht wurden. Die Schwelle für die Steigerung der Difenzoquat-Aufnahme durch Netzmittel lag bei Flug-Hafer sehr niedrig (0,05 g 1−1), bei der Ackerbohne vielhöher (〉0,5 g 1−1). Bei 2,4-D wurden bei beiden Arten zur deutlichen Förderung der Aufnahme Netzmittelkonzentrationen von 〉0,5 g 1−1 benötigt. Obwohl Netzmittel mit niedrigem EO-Gehalt (5–6) die Difenzoquat-Aufnahme weniger förderten als solche mit höherem Gehalt (10–20). besonders bei Flug-Hafer, ergab sich für die Förderung der 2,4-D-Aufnahme kaum eine Abhängigkeit vom EO-Gehalt des Netzmittels. Additive mit feuchtigkeitshaltenden Eigenschaften förderten auch die Aufnahme von Difenzoquat, aber weniger als alkoholische oder nonylphenolische Netzmittel. Die Translokation der Mischungen der beiden 14C-Herbizide stand in direktem Verhäitnis zur Radioaktivitätsmenge, die in das Blattgewebe aufgenommen wurde.

Notes: abstract The purpose of undertaking repeat examinations in oral epidemiology has been discussed. Since many of the published methods of demonstrating repeatability do not allow the influence of error to be quantified, the value of estimating reliability was investigated. This is based on the assumption that the coefficient of reliability is the ratio of true to total variance, where total variance is the sum of true and error variance. It was suggested that the reliability coefficient together with error variance should be used to express repeatability in oral epidemiology since reliability is closely related to the efficiency of the study and allows the relative importance of error to be assessed. Five methods for determining the reliability of dental caries data have been investigated and compared; all but one required the reexamination of subjects. The fifth method, although not requiring a reexamination, was considered unsuitable for use in caries studies. The two methods recommended for use in prevalence surveys were simple to use and provided data from which the reliability of incremental scores might be calculated.

Notes: Abstract The Manchester fluoride tablet trial was a pragmatic study to assist the Health Authority to decide whether to provide fluoride tablets daily to all primary schoolchildren in the District prior to water fluoridation being introduced. Twenty-two primary schools took part, half being allocated at random to the public health programme while the other half remained untreated. The average age at baseline was 5 yr 3 months. Costs were monitored throughout the trial and tangible and intangible benefits assessed. 263 children in the test schools and 266 in the control schools completed the trial. The cost per child was £4.39 for the 3 yr of the trial. Economies resulting from an increase in size of a substantive scheme were estimated producing a cost of £1.98/child over a 3-yr period for a tangible benefit of £3.23. In addition, the intangible benefits of less anxiety, less treatment, and fewer experiences of general anaesthesia need consideration.

Notes: Abstract 751 14- and 15-year old children completed a 3-year, double-blind, caries preventive program. The effects of daily, supervised toothbrushing with an 0.76% sodium monofluorophosphate dentifrice, rinsing with a 0.05% sodium fluoride mouthrinse, and the combined effects of the two treatments were investigated. Both the dentifrice and mouthrinse reduced the incidence of dental caries, but their combined use at die same lime had no greater effect than either used alone.

Notes: Abstract Electron-microscopic examination in conjunction with extraction procedures and chemical analysis have confirmed that a suberin-like lipid biopolymer is located within the concentric polylamellate layers found in the secondary cell walls of green cotton fibres (Gossypium hirsutum cv. green lint). A polymer of similar ultrastructure and chemical constitution also occurs mainly in the secondary seed-coat walls of the outer epidermis of both green and white varieties of G. hirsutum. The suberins composed of predominantly C22 compounds are, however, markedly different from those present in the periderms of the same plants; these comprise mainly C16 and C18 compounds. Long-chain 1-alkanols (C26−C36) and alkanoic acids (C16−C36) are the principal components of the wax from white fibres but these lipid classes comprise a much smaller proportion of that from green fibres. unidentified highmolecular-weight compounds were the major constituents of the green-fibre was extract which also contains a number of yellow-green pigments, probably flavonoid in nature. These pigments are thought to be associated with the ultrahistochemical reaction with silver proteinate that was observed only in the green-fibre cell walls. A total of 16 wild and cultivated cotton species were examined with the electron microscope for the presence of suberin. The outer seed-coat epidermis of all the examined species but only the fibres of the wild ones were found to be suberized. Among the analysed mutants of fibre colour in G. hirsutum only the gene Lg (green lint) seemed to be associated with suberin.

Notes: Summary Barley yellow dwarf (BYDV) is a group a closely related viruses which cause economic losses in a wide range of graminaceous species throughout the world. Barley plants can be protected from the effects of BYDV by the ‘Yd2’ resistance gene. Plants which contain the ‘Yd2’ gene also contain a constitutively expressed polypeptide which was not found in any plants without ‘Yd2’. Conversely, BYDV susceptible plants contain another constitutively expressed polypeptide which was not found in any of the BYDV-resistant lines examined. These two polypeptides appear to have the same molecular weight (as assessed by SDS-PAGE) and only slightly different iso-electric points. They also appear to contain an extensive range of similar antigenic determinants. Both polypeptides were found in F1 hybrids made from resistant and susceptible plants. We suggest that these two polypeptides are the products of two allelic genes. Analysis of near-isogenic lines showed that the locus which controls the ‘Yd2’ resistance gene and the locus controlling the synthesis of the two polypeptides may be within ± 9 cM of each other. We have developed a Western blot technique which allows assessment of barley lines, 4-days after seed imbibition, for the presence of the ‘Yd2’ gene.

Notes: Summary The secondary cell walls of fibres of the green lint variety of cotton are strongly autofluorescent and stain with both Sudan III and osmium tetroxide. In the electron microscope thin sections of aldehydeosmium fixed fibres show concentric, osmiophilic layers in the walls, each separated by cellulosic material. The number of these layers corresponds approximately to the number of days of secondary wall formation suggesting a periodic deposition. At higher magnifications each osmiophilic layer consists of several alternating electron opaque and electron translucent lamellae with a periodicity of about 4.2 nm. Ovules of the same variety culturedin vitro, in the dark and at constant temperature, also develop green fibres exhibiting the same ultrastructural features. Chemical analysis of the isolated fibre cell walls confirmed the presence of suberin, the dominant monomer being 22-hydroxydocosanoic acid (65% of the total monomeric mixture). These findings strongly suggest that suberin, as well as waxes, are associated with the formation of the concentric rings of lamellated lipid material which characterise the walls of green lint cotton fibres. A similar polymeric lipid also occurs in green lint epidermal cells that do not form fibres. However, in the white lint variety this polymer is restricted to the outer part of non-fibre forming epidermal cells and to the lateral walls at the base of the fibres.