15 resultados para Drinking of alcoholic beverages

em Aston University Research Archive


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The yeast Saccharomyces cerevisiae is an important model organism for the study of cell biology. The similarity between yeast and human genes and the conservation of fundamental pathways means it can be used to investigate characteristics of healthy and diseased cells throughout the lifespan. Yeast is an equally important biotechnological tool that has long been the organism of choice for the production of alcoholic beverages, bread and a large variety of industrial products. For example, yeast is used to manufacture biofuels, lubricants, detergents, industrial enzymes, food additives and pharmaceuticals such as anti-parasitics, anti-cancer compounds, hormones (including insulin), vaccines and nutraceuticals. Its function as a cell factory is possible because of the speed with which it can be grown to high cell yields, the knowledge that it is generally recognized as safe (GRAS) and the ease with which metabolism and cellular pathways, such as translation can be manipulated. In this thesis, these two pathways are explored in the context of their biotechnological application to ageing research: (i) understanding translational processes during the high-yielding production of membrane protein drug targets and (ii) the manipulation of yeast metabolism to study the molecule, L-carnosine, which has been proposed to have anti-ageing properties. In the first of these themes, the yeast strains, spt3?, srb5?, gcn5? and yTHCBMS1, were examined since they have been previously demonstrated to dramatically increase the yields of a target membrane protein (the aquaporin, Fps1) compared to wild-type cells. The mechanisms underlying this discovery were therefore investigated. All high yielding strains were shown to have an altered translational state (mostly characterised by an initiation block) and constitutive phosphorylation of the translational initiation factor, eIF2a. The relevance of the initiation block was further supported by the finding that other strains, with known initiation blocks, are also high yielding for Fps1. A correlation in all strains between increased Fps1 yields and increased production of the transcriptional activator protein, Gcn4, suggested that yields are subject to translational control. Analysis of the 5´ untranslated region (UTR) of FPS1 revealed two upstream open reading frames (uORFs). Mutagenesis data suggest that high yielding strains may circumvent these control elements through either a leaky scanning or a re-initiation mechanism. In the second theme, the dipeptide L-carnosine (ß-alanyl-L-histidine) was investigated: it has previously been shown to inhibit the growth of cancer cells but delay senescence in cultured human fibroblasts and extend the lifespan of male fruit flies. To understand these apparently contradictory properties, the effects of L-carnosine on yeast were studied. S. cerevisiae can respire aerobically when grown on a non-fermentable carbon source as a substrate but has a respiro-fermentative metabolism when grown on a fermentable carbon source; these metabolisms mimic normal cell and cancerous cell metabolisms, respectively. When yeast were grown on fermentable carbon sources, in the presence of L-carnosine, a reduction in cell growth and viability was observed, which was not apparent for cells grown on a non-fermentable carbon source. The metabolism-dependent mechanism was confirmed in the respiratory yeast species Pichia pastoris. Further analysis of S. cerevisiae yeast strains with deletions in their nutrient-sensing pathway, which result in an increase in respiratory metabolism, confirmed the metabolism-dependent effects of L-carnosine.

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Objectives. To elicit students' salient beliefs in relation to binge drinking, and to examine the extent to which individual salient beliefs predict theory of planned behaviour (TPB) constructs in relation to binge drink, and actual drinking behaviour assessed later that evening. Design. Longitudinal, over a single evening. Methods. 192 students were recruited as they entered a campus bar at the beginning of the evening. They completed questionnaires with open-ended questions eliciting beliefs concerning binge drinking, and ratings scales assessing standard TPB constructs in relation to binge drinking. At the end of the evening, 181 completed a second questionnaire and recorded the number of alcoholic drinks they had consumed. Results. Beliefs were reliably coded (all kappas =0.79). Students with higher intentions to binge drink were more likely to believe that their friends approved of binge drinking, and that (lack of) money would make it difficult. Students who reported drinking more alcohol at the end of the evening were more likely to believe that getting drunk is an advantage/what they would like about binge drinking tonight, that their sports teams would approve, and that celebrating, drinking patterns, and environment would make it easy to binge drink. Conclusions. The present study has identified the individually salient beliefs relating to drinking behaviour that the TPB states should be addressed by interventions to alter behaviour, and which that should be assessed as mediators in intervention research. As a whole, these findings highlight the importance of perceived peer norms in binge drinking in this population, and support the idea of interventions to challenge the perception of social pressure to binge drink. ©2011 The British Psychological Society.

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Azidoprofen {2-(4-azidophenyl)propionic acid; AZP}, an azido-substituted arylalkanoic acid, was investigated as a model soft drug candidate for a potential topical non-steroidal anti-inflammatory agent (NSAIA). Reversed-phase high performance liquid chromatography (HPLC) methods were developed for the assay of AZP, a series of ester analogues and their· degradation products. 1H-NMR spectroscopy was also employed as an analytical method in selected cases. Reduction of the azido-group to the corresponding amine has been proposed as a potential detoxification mechanism for compounds bearing this substituent. An in vitro assay to measure the susceptibility of azides towards reduction was developed using dithiothreitol as a model reducing agent. The rate of reduction of AZP was found to be base-dependent, hence supporting the postulated mechanism of thiol-mediated reduction via nucleophilic attack by the thiolate anion. Prodrugs may enhance topical bioavailability through the manipulation of physico-chemical properties of the parent drug. A series of ester derivatives of AZP were investigated for their susceptibility to chemical and enzymatic hydrolysis, which regenerates the parent acid. Use of alcoholic cosolvents with differing alkyl functions to that of the ester resulted in transesterification reactions, which were found to be enzyme-mediated. The skin penetration of AZP was assessed using an in vitro hairless mouse skin model, and silastic membrane in some cases. The rate of permeation of AZP was found to be a similar magnitude to that of the well established NSAIA ibuprofen. Penetration rates were dependent on the vehicle pH and drug concentration when solutions were employed. In contrast, flux was independent of pH when suspension formulations were used. Pretreatment of the skin with various enhancer regimes, including oleic acid and azone in propylene glycol, promoted the penetration of AZP. An intense IR absorption due to the azide group serves as a highly diagnostic marker, enabling azido compounds to be detected in the outer layers of the· stratum corneum following their application to skin, using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). This novel application enabled a non-invasive examination of the percutaneous penetration enhancement of a model azido compound in vivo in man, in the presence of the enhancer oleic acid.

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Today, alongside many other proscriptions, women are expected to abstain or at least limit their alcohol consumption during pregnancy. This advice is reinforced through warning labels on bottles and cans of alcoholic drinks. In most (but not all) official policies, this is linked to a risk of Foetal Alcohol Syndrome (FAS) or one of its associated conditions. However, given that there is little medical evidence that low levels of alcohol consumption have an adverse impact on the foetus, we need to examine broader societal ideas to explain why this has now become a policy concern. This paper presents a quantitative and qualitative assessment of analysis of the media in this context. By analysing the frames over time, this paper will trace the emergence of concerns about alcohol consumption during pregnancy. It will argue that contemporary concerns about FAS are framed around a number of pre-existing discourses including alcohol consumption as a social problem, heightened concerns about children at risk and shifts in ideas about the responsibility of motherhood including during the pre-conception and pregnancy periods. Whilst the newspapers regularly carried critiques of the abstinence position now advocated, these challenges focused did little to refute current parenting cultures.

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Technological advances have driven some attempt of vital parameters monitoring in adverse environments; these improvements will make possible to monitor cardiac activity also in automotive environments. In this scenario, heart rate changes associated with alcohol consumption, become of great importance to assess the drivers state during time. This paper presents the results of a first set of experiments aimed to discover heart rate variability modification induced by moderate assumption of alcoholic drink (i.e. single draft beer) as that typically occurs in weekend among some people. In the study, twenty subjects were enrolled and for each of them two electrocardiographic recordings were carried out: the first before alcohol ingestion and the second after 25-30 minutes. Each participant remained fasting until the second ECG acquisition was completed. ECG signal were analyzed by typical timedomain, frequency and non linear analysis. Results showed a small increase in LF/HF ratio which reflects a dominance of the sympathetic system over the parasympathetic system, and an increase in signal complexity as proven by non linear analysis. However, the study highlighted the need to monitor HRV starting from alcohol ingestion until its complete metabolization to allow a more precise description of its variation. © Springer International Publishing Switzerland 2014.

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To investigate the neurotoxic effects of aluminium (Al) three studies were carried out in which Al was administered: 1) in the diet, 2) as a suspension of aluminium acetate in drinking water and 3) a long-term study in which aluminosilicates were incorporated into a pelleted diet. Admistration of Al in the drinking water significantly reduced total brain biopterin. However, no significant affect of Al in the diet on total bipterins or BH4 synthesis was found.

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Aims: To assess the effectiveness of a digital-story intervention (short videos made by young people) seeking to reduce the prevalence of young people's binge drinking in Caerphilly. Method: A quasi-experimental design was adopted with three intervention sites and one control site providing the sample (mainly aged 1415 years). Three rounds of self-completion questionnaires, completed prior (T1), immediately after (T2) and 6 months after the intervention (T3). Findings: A total of 1031 questionnaires completed across the three time-points. Two-factor ANOVAs revealed a positive effect on knowledge for the intervention sample. The intervention group results showed stable attitudes towards drinking at the three time-points whilst the control group showed increasing positive attitudes towards drunkenness over the same time period. Intentions towards drunkenness were higher in the control group than the intervention group at T2 (ControlT1 Mean 3.37, T2 Mean 3.90; interventionT1 Mean 3.26, T2 Mean 3.29). Intervention participants got drunk on fewer occasions in the last week (mean occasions last week 1.57) compared to control participants (mean occasions last week 2.00), with the difference approaching statistical significance (F 1.90, p 0.07). Conclusions: Promoting negative attitudes towards drunkenness, alongside a greater sense of control and potential regret about drunkenness are likely to be important factors when considering how to change people's intentions to drink. The study shows the potential to reduce the frequency of drinking behaviour when intentions are changed, and provides recommendations for future interventions of this nature. © 2010 Informa UK Ltd.

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This paper analyzes the performance of Dutch drinking water utilities before and after the introduction of sunshine regulation, which involves publication of the performance of utilities but no formal price regulation. By decomposing profit change into its economic drivers, our results suggest that, in the Dutch political and institutional context, sunshine regulation was effective in improving the productivity of publicly organised services. Nevertheless, while sunshine regulation did bring about a moderate reduction in water prices, sustained and substantial economic profits suggest that it may not have the potential to fully align output prices with economic costs in the long run. In methodological terms, the DEA based profit decomposition is extended to robust and conditional non-parametric efficiency measures, so as to account better for both uncertainty and differences in operating environment between utilities.

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Aims: To investigate the utility of an extended Theory of Planned Behaviour (TPB), including descriptive norms and anticipated regret, in predicting binge-drinking intentions and behaviour. Methods: A total of178 undergraduates completed a questionnaire containing measures of TPB variables, descriptive norms, anticipated regret, and previous binge-drinking behaviour. One week later, 104 students completed a measure of binge-drinking behaviour. Results: Hierarchical regression demonstrated that attitudes (beta = 0.30, P < 0.001) and anticipated regret (beta = 0.47, P < 0.001) were significant predictors of intentions, with the final equation accounting for 58% of the variance. Hierarchial regression found that intentions (beta = -0.21, P < 0.05) and previous binge-drinking behaviour (beta = 0.36, P < 0.01) predicted current drinking behaviour, accounting for 33% of the variance. Conclusions: The study suggests that modifying attitudes and inducing regret may be effective strategies for reducing binge-drinking intentions among undergraduates, which should reduce subsequent binge-drinking behaviour. © The Author 2006. Published by Oxford University Press on behalf of the Medical Council on Alcohol. All rights reserved.

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In recent treatments of habitual social behaviour, habits are conceptualized as a form of goal-directed automatic behaviour that are mentally represented as goal-action links. Three experiments tested this conceptualization in the context of students' drinking (alcohol consumption)habits. Participants were randomly assigned to conditions where either a goal related to drinking behaviour (socializing) was activated, or an unrelated goal was activated. In addition, participants' drinking habits were measured. The dependent variable in Experiments 1 and 2 was readiness to drink, operationalized by speed of responding to the action concept 'drinking' in a verb verification task. Experiment 3 used the uptake of a voucher to measure drinking behaviour. Findings supported the view that when habits are established, simply activating a goal related to the focal behaviour automatically elicits that behaviour. These findings are consistent with a goal-dependent conception of habit. Possibilities for interventions designed to attenuate undesirable habitual behaviours are considered.

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Energy drinks have become very popular over the past few years with over half the student population in colleges and universities consuming them at least once a month (Malinauskas et al., 2007). It has been reported that the most common reasons why students consume energy drinks are to maintain alertness, reduce symptoms of hangover, increase energy, to help with driving and to prevent sleepiness (Attila and Cakir, 2011; Malinauskas et al., 2007). Previous research has suggested that energy drinks enhance sensorimotor speed, behaviour, and reduce levels of fatigue (Alford et al., 2001; Horne and Reyner, 2001; Howard and Marczinski, 2010; Kennedy and Scholey, 2004; Smit et al., 2004). The two key ingredients found in energy drinks are caffeine and glucose which have been examined together and alone, which have indicated enhanced reaction times, improvement in both verbal memory and sustained attention and more recently there is evidence to show that expectancy may play a key role in predicting intentions of future consumption (Adan and serra-Grabulosa, 2010). According to Kirsch (1997) people have specific expectations when they consume psychoactive substances that trigger physiological and psychological reactions, which tend to be independent of the psychoactive substance ingested. The concept of expectancy effects can be unambiguous especially when the information provided to the participants prior to the experimental study is specific to a possible outcome response. This thesis investigated the extent of expectancy effect on cognition and mood when psychoactive drinks containing caffeine and glucose were consumed in comparison to non-psychoactive drinks. The investigation commenced with examining the independent effects of caffeine and glucose, followed by the combination of caffeine and glucose as an energy drink on mood and cognition. The investigation advanced by comparing drink presentation effects (i.e., consuming the experimental drink from a branded bottle versus from a glass) irrespective of drink content on mood and cognition. Finally, the investigation lead to exploring what factors may predict expectancy effects when participants’ consumed psychoactive drinks among healthy adults. This was done by applying the Theory of Planned Behaviour model (TPB) (Azjen, 1991) to explore the contribution of specific attitudes, subjective norms and perceived behavioural control to the extent of expectancy effects as well as to behavioural intention, with additional variables including; beliefs, habits, past-behaviour, selfidentity. Self-identity representing someone who drinks energy drinks regularly. The level of internal consistency for Cronbach’s alpha was conducted for each variable within the TPB model and for the additional variables included for test reliability. This thesis consisted of four studies, which found that consumption of caffeine and glucose independently and also in combination resulted in psychoactive effects on mood and cognition. Experiment 2 was the only study, which indicated an expectancy effect for immediate verbal recall task and the mood subscale tension. Conversely, for experiment 4 there was a reverse effect found for the immediate verbal recall task. However, there were significant expectancy and psychoactive effects found for mood subscales throughout the four studies. It was also found that the TPB model had two significant variables past-behaviour and self-identity predicted intentions suggesting that participants who regularly consume psychoactive beverages have salient beliefs about consuming psychoactive drinks and the TPB model can be utilised to predict their intentions. Furthermore, the Theory of planned behaviour model found that habit and self-identity significantly predicted participants’ expectancy effects on the vigour. Indicating consumers of energy drinks are familiar with expected outcome response. This model was unsuccessful in predicting expectancy response for cognitive performance. Thus, overall the findings from the four studies indicated that caffeine and glucose have cognitive enhancing properties, which also positively improve mood. However, expectancy effects have been identified for mood only, whereas the overall findings within this thesis were unable to identify significant predictors of expectancy effect and response.

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Highlights •This paper assesses the validity of the DMQ-R (Cooper, 1994) among university students in six different European countries. •Results provide support for similar DMQ-R factor structures across countries. •Drinking motives have similar meanings among European university students.

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Background: The present study tested the utility of the theory of planned behaviour (TPB), augmented with anticipated regret, as a model to predict binge-drinking intentions and episodes among female and male undergraduates and undergraduates in different years of study. Method: Undergraduate students (N = 180, 54 males, 126 females, 60 per year of study) completed baseline measures of demographic variables, binge-drinking episodes (BDE), TPB constructs and anticipated regret. BDE were assessed one-week later. Results: The TPB accounted for 60% of the variance in female undergraduates' intentions and 54% of the variance in male undergraduates' intentions. The TPB accounted for 57% of the variance in intentions in first-year undergraduates, 63% of the variance in intentions in second-year undergraduates and 68% of the variance in intentions in final-year undergraduates. Follow-up BDE was predicted by intentions and baseline BDE for female undergraduates as well as second- and final-year undergraduates. Baseline BDE predicted male undergraduates’ follow-up BDE and first-year undergraduates’ follow-up BDE. Conclusion: Results show that while the TPB constructs predict undergraduates’ binge-drinking intentions, intentions only predict BDE in female undergraduates, second- and final-year undergraduates. Implications of these findings for interventions to reduce binge drinking are outlined.