Searching new targets for the control of Black Rot: following the role of host factors modulating the infection process of Phyllosticta ampelicida.

Black Rot is a grapevine disease caused by the ascomycete Phyllosticta ampelicida. Neglected so far, this is developing into a pertinent problem in organic viticulture as resistant varieties are still lacking. Here, we follow cellular details of the infection process in the susceptible vinifera variety Müller-Thurgau and screen the ancestral European wild grapevine (V. vinifera sylvestris) for resistance to Black Rot. Using a standardized infection assay, we follow fungal development using LTSEM and quantify key stages on different hosts using fluorescence microscopy. There is considerable variation in susceptibility, which is associated with more rapid leaf maturation. Hyphal growth on different carbon sources shows a preference for pectins over starch, cellulose or xylans. In the resistant sylvestris genotypes Ketsch 16 and Ketsch 18 we find that neither spore attachment nor appressorium formation, but hyphal elongation is significantly inhibited as compared to Müller-Thurgau. Moreover, defence-related oxidative burst and accumulation of phenolic compounds is stimulated in the resistant genotypes. We arrive at a model, where more rapid maturation of the cell wall in these sylvestris genotypes sequesters pectins as major food source and thus block hyphal elongation. This paves the way for introgression of genetic factors responsible for cell wall maturation into V. vinifera to develop Black Rot-resistant varieties of grapevine.

Realization of a push-me-pull-you swimmer at low Reynolds numbers.

Locomotion at low Reynolds numbers encounters stringent physical constraints due to the dominance of viscous over inertial forces. A variety of swimming microorganisms have demonstrated diverse strategies to generate self-propulsion in the absence of inertia. In particular, ameboid and euglenoid movements exploit shape deformations of the cell body for locomotion. Inspired by these biological organisms, the 'push-me-pull-you' (PMPY) swimmer (Avron J Eet al2005New J. Phys.7234) represents an elegant artificial swimmer that can escape from the constraints of the scallop theorem and generate self-propulsion in highly viscous fluid environments. In this work, we present the first experimental realization of the PMPY swimmer, which consists of a pair of expandable spheres connected by an extensible link. We designed and constructed robotic PMPY swimmers and characterized their propulsion performance in highly viscous silicone oil in dynamically similar, macroscopic experiments. The proof-of-concept demonstrates the feasibility and robustness of the PMPY mechanism as a viable locomotion strategy at low Reynolds numbers.

Young people's exposure to point-of-sale tobacco products and promotions.

OBJECTIVES: Point of sale (POS) displays are one of the most important forms of tobacco marketing still permitted in many countries. Reliable methods for measuring exposure to such displays are needed in order to assess their potential impact, particularly on smoking attitudes and uptake among young people. In this study we use a novel method for evaluating POS exposure based on young people's use of retail outlets and recall of tobacco displays and observational data on the characteristics of displays. STUDY DESIGN: Observational audit of retail outlets (n = 96) and school-based pupil survey (n = 1482) in four Scottish communities reflecting different levels of social deprivation and urbanisation, conducted in 2013 before legislation to remove POS displays was implemented in supermarkets. METHODS: Measures were taken of: visibility and placement of tobacco displays; internal and external advertising; display unit size, branding and design; visibility of pack warnings; proximity of tobacco products to products of potential interest to children and young people; pupils' self-reported frequency of visiting retail outlets; and pupils' recall of tobacco displays. Variation in POS exposure across social and demographic groups was assessed. RESULTS: Displays were highly visible within outlets and, in over half the stores, from the public footway outside. Tobacco products were displayed in close proximity to products of interest to children (e.g. confectionery, in 70% of stores). Eighty percent of pupils recalled seeing tobacco displays, with those from deprived areas more likely to recall displays in small shops. When confectioners, tobacconists and newsagents (CTNs) and grocery/convenience stores (two of the outlet types most often visited by young people) were examined separately, average tobacco display unit sizes were significantly larger in those outlets in more deprived areas. CONCLUSIONS: POS displays remain a key vector in most countries for advertising tobacco products, and it is important to develop robust measures of exposure. The data reported in this paper provide a baseline measure for evaluating the efficacy of legislation prohibiting such displays.

Does exposure to cigarette brands increase the likelihood of adolescent e-cigarette use? A cross-sectional study.

OBJECTIVE: To examine the relationship between tobacco cigarette brand recognition, and e-cigarette use in adolescents. DESIGN: Cross-sectional observational study. SETTING: High schools in Scotland. PARTICIPANTS: Questionnaires were administered to pupils in Secondary 2 (S2 mean age: 14.0 years) and Secondary 4 (S4 mean age: 15.9 years) across 4 communities in Scotland. An 86% response rate with a total sample of 1404 pupils was achieved. MAIN OUTCOME MEASURES: Self-reported previous use of e-cigarettes and self-reported intention to try e-cigarettes in the next 6 months. RESULTS: 75% (1029/1377) of respondents had heard of e-cigarettes (69.5% S2, 81.1% S4), and of these, 17.3% (10.6% S2, 24.3% S4 n=1020) had ever tried an e-cigarette. 6.8% (3.7% S2, 10.0% S4 n=1019) reported that they intended to try an e-cigarette in the next 6 months. Recognition of more cigarette brands was associated with greater probability of previous e-cigarette use (OR 1.20, 99% CI 1.05 to 1.38) as was having a best friend who smoked (OR 3.17, 99% CI 1.42 to 7.09). Intention to try e-cigarettes was related to higher cigarette brand recognition (OR 1.41, 99% CI 1.07 to 1.87), hanging around in the street or park more than once a week (OR 3.78, 99% CI 1.93 to 7.39) and living in areas of high tobacco retail density (OR 1.20, 99% CI 1.08 to 1.34). Never having smoked was a protective factor for both future intention to try, and past e-cigarette use (OR 0.07, 99% CI 0.02 to 0.25; and OR 0.10, 99% CI 0.07 to 0.16, respectively). CONCLUSIONS: Higher cigarette brand recognition was associated with increased probability of previous use and of intention to use e-cigarettes. The impact of tobacco control measures such as restricting point-of-sale displays on the uptake of e-cigarettes in young people should be evaluated.

The density of tobacco retailers in home and school environments and relationship with adolescent smoking behaviours in Scotland.

BACKGROUND: Neighbourhood retailing of tobacco products has been implicated in affecting smoking prevalence rates. Long-term smoking usually begins in adolescence and tobacco control strategies have often focused on regulating 'child spaces', such as areas in proximity to schools. This cross-sectional study examines the association between adolescent smoking behaviour and tobacco retail outlet density around home and school environments in Scotland. METHODS: Data detailing the geographic location of every outlet registered to sell tobacco products in Scotland were acquired from the Scottish Tobacco Retailers Register and used to create a retail outlet density measure for every postcode. This measure was joined to individual responses of the Scottish Schools Adolescent Lifestyle and Substance Use Survey (n=20 446). Using logistic regression models, we explored the association between the density of retailers, around both home and school address, and smoking behaviours. RESULTS: Those living in the areas of highest density of retailers around the home environment had 53% higher odds of reporting having ever smoked (95% CI 1.27 to 1.85, p<0.001) and 47% higher odds of reporting current smoking (95% CI 1.13 to 1.91 p<0.01). Conversely, those attending schools in areas of highest retail density had lower odds of having ever smoked (OR 0.66, 95% CI 0.50 to 0.86 p<0.01) and lower odds of current smoking (OR 0.75, 95% CI 0.59 to 0.95, p<0.05). CONCLUSIONS: The density of tobacco retail outlets in residential neighbourhoods is associated with increased odds of both ever smoked and current smoking among adolescents in Scotland. Policymakers may be advised to focus on reducing the overall density of tobacco outlets, rather than concentrating on 'child spaces'.

E-cigarette marketing in UK stores: an observational audit and retailers' views.

OBJECTIVES: To explore how e-cigarettes are being promoted at point of sale in the UK and how retailers perceive market trends. SETTING: Fixed retail outlets subject to a ban on the display of tobacco products. PARTICIPANTS: Observational audit of all stores selling tobacco products (n=96) in 4 Scottish communities, conducted over 2 waves 12 months apart (2013-2014), and qualitative interviews with small retailers (n=25) in 4 matched communities. PRIMARY AND SECONDARY OUTCOME MEASURES: The audit measured e-cigarette display characteristics, advertising materials and proximity to other products, and differences by area-level disadvantage. Interviews explored retailers' perceptions of e-cigarette market opportunities and risks, and customer responses. RESULTS: The number of e-cigarette point-of-sale display units and number of brands displayed increased between waves. E-cigarettes were displayed close to products of interest to children in 36% of stores. Stores in more affluent areas were less likely to have external e-cigarette advertising than those in deprived areas. Although e-cigarettes delivered high profit margins, retailers were confused by the diversity of brands and products, and uncertain of the sector's viability. Some customers were perceived to purchase e-cigarettes as cessation aids, and others, particularly low-income smokers, as a cheaper adjunct to conventional tobacco. CONCLUSIONS: E-cigarette point-of-sale displays and number of brands displayed increased over 12 months, a potential cause for concern given their lack of regulation. Further scrutiny is needed of the content and effects of such advertising, and the potentially normalising effects of placing e-cigarettes next to products of interest to children.