Timothy A Hogg

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Molecular electronics are difficult to fabricate with precise positioning of large numbers of devices and their connections. Self-assembly techniques can create such circuits but with some random variation in their connection locations and characteristics. Using simulations, we show how to produce reliable circuits in spite of this variation by adding(More)
The aim of this work was to investigate the effect of phenolic acids on cell membrane permeability of lactic acid bacteria from wine. Several phenolic acids were tested for their effects on the cell membrane of Oenococcus oeni and Lactobacillus hilgardii by measuring potassium and phosphate efflux, proton influx and by assessing culture viability employing(More)
AIMS To determine the effect of several wine-associated, phenolic acids on the growth and viability of strains of Oenococcus oeni and Lactobacillus hilgardii. METHODS AND RESULTS Growth was monitored in ethanol-containing medium supplemented with varying concentrations of hydroxybenzoic acids (p-hydroxybenzoic, protocatechuic, gallic, vanillic and(More)
Hanseniaspora guilliermondii and Hanseniaspora uvarum were tested in grape must fermentations as pure and mixed starter cultures with Saccharomyces cerevisiae. In pure cultures, the specific growth rates found were 0.29 h(-1) for H. uvarum, 0.23 h(-1) for H. guilliermondii and 0.18 h(-1) for S. cerevisiae. No significant differences were observed between(More)
The aim of this work was to study the relationship between carotenoid contents in grapevine berries and plant water status. For this purpose, a black grapevine variety, Vitis vinifera L. cv. Touriga Nacional, was studied. The experiments were carried out in the same Douro vineyards, with plants of the same age, in two different water retention soils. A(More)
The negative effects of oxygen on white wine quality and the various factors which influence it (including temperature, dissolved oxygen, pH, and free SO(2)) are well documented both at the sensory and compositional levels. What is less defined is the quantitative relationship between these parameters and the kinetics of the development of the negative(More)
AIMS To evaluate the effect of wine phenolic compounds on the production of volatile phenols (4-vinylphenol [4VP] and 4-ethylphenol [4EP]) from the metabolism of p-coumaric acid by lactic acid bacteria (LAB). METHODS AND RESULTS Lactobacillus plantarum, Lactobacillus collinoides and Pediococcus pentosaceus were grown in MRS medium supplemented with(More)
AIMS The development of a simple and reliable procedure, compatible with routine use in wineries, for the presumptive detection of Brettanomyces/Dekkera from wine and wine-environment samples. METHODS AND RESULTS The method of detection of these yeasts employs a selective enrichment medium. The medium contains glucose (10 g l(-1)) as carbon and energy(More)
The migration of chemicals from food contact materials into foods is an important issue in food safety. The assessment of materials compliance with regulations includes migration monitoring for many monomers and additives. However, it is recognized that predictive mathematical modelling can be used in many cases, to avoid or to reduce the effort on(More)
Oxidative degradation of white wines can be described sensorially as developing from a loss at positive aroma characteristics, through the development of negative aromas to a linel stage of chromatic alterations. This work attempts to relate the oxidation "status" evaluate by potentiometric titrations, with sensorial degradation and the levels of substances(More)