4,246 research outputs found
A qualitative exploration of consumers’ perceived impacts, behavioural reactions, and future reflections of the EU Tobacco Products Directive (2017) as applied to electronic cigarettes
Background: Electronic cigarette regulations included in the Tobacco Products Directive (TPD), Article 20, implemented in Europe by May 2017, aimed to improve safety for e-cigarette consumers, and prevent uptake among non-smokers, particularly young people. Before implementation, there were significant concerns from consumers, industry, and some in the scientific community about the potential negative impact of the TPD on people using e-cigarettes to stay stopped from smoking. To date, there is limited evidence on how the TPD has affected consumers. This study aimed to add insight into how consumers perceived and experienced the regulations. Methods: Qualitative data, collected between March 2018 and March 2019, relating to participant views of the TPD were extracted from 160 interviews/extended surveys of e-cigarette consumers as part of a wider study into e-cigarette use trajectories (ECtra study). Data were thematically analysed. Results: Awareness of the TPD amongst consumers was not universal. Participants’ smoking behaviour did not appear to be influenced by the legislation. Participants were reassured by manufacturing regulations and requirements for ingredients labels. Participants responded negatively to changes perceived to cause inconvenience and extra plastic waste. The product restrictions prompted some participants to purchase non-compliant products illegally, potentially putting their safety at risk. Conclusions: E-cigarette regulation should focus on ensuring product safety. Raising awareness of the TPD amongst consumers and smokers could be beneficial
Development of a method for optimal maneuver analysis of complex space missions
A system that allows mission planners to find optimal multiple-burn space trajectories easily is described. Previously developed methods with different gravity assumptions perform the optimization function. The power of these programs is extended by a method of costate estimation. A penalty function method of constraining coast arc times to be positive is included. The capability of the method is demonstrated by finding the optimal control for three different space missions. These include a shuttle abort-once-around mission and two- and three-burn geosynchronous satellite-placement missions
Modeling the lowest-cost splitting of a herd of cows by optimizing a cost function
Animals live in groups to defend against predation and to obtain food.
However, for some animals --- especially ones that spend long periods of time
feeding --- there are costs if a group chooses to move on before their
nutritional needs are satisfied. If the conflict between feeding and keeping up
with a group becomes too large, it may be advantageous to some animals to split
into subgroups of animals with similar nutritional needs. We model the costs
and benefits of splitting by a herd of cows using a cost function (CF) that
quantifies individual variation in hunger, desire to lie down, and predation
risk. We model the costs associated with hunger and lying desire as the
standard deviations of individuals within a group, and we model predation risk
as an inverse exponential function of group size. We minimize the cost function
over all plausible groups that can arise from a given herd and study the
dynamics of group splitting. We explore our model using two examples: (1) we
consider group switching and group fission in a herd of relatively homogeneous
cows; and (2) we examine a herd with an equal number of adult males (larger
animals) and adult females (smaller animals).Comment: 19 pages, 10 figure
A multi-centre cluster randomised controlled trial evaluating the effectiveness of e-cigarettes compared with usual care for smoking cessation when offered to smokers accessing homeless services: methodological challenges and experiences of collaboration.
Around 80% of people experiencing homelessness smoke. E-cigarettes (ECs) are an effective quitting aid, but they have not been widely tested in this population. Project SCeTcH aims to evaluate the offer of an EC or usual care (UC) to smokers accessing homeless centres.
A multi-centre two-arm cluster randomised controlled trial (RCT), including 32 homeless centres across Great Britain (480 participants). Randomisation includes either an EC with weekly allocations of e-liquid for 4-weeks or UC comprising very brief advice and signposting to a stop smoking service.
After year 1, 27 centres and 240 participants have been recruited and retention rates at 4- and 24- weeks are 67% and 70% respectively. Challenges include working with multiple centres with different structures, provision, and client needs; reconciling risk of bias with the practicalities of working in this sector; the ongoing impact of Covid; changing models of care and practice; and juggling the needs of different collaborators researchers and health and social care organisations
This is the first cluster RCT to assign smokers experiencing homelessness to an EC and UC intervention to measure smoking abstinence and risky smoking practices. Running trials in this population requires the need to understand the realistic needs of these individuals and services, and to work pragmatically and flexibly within the remit of the trial protocol. Ultimately, if effective, the results will be used to inform the larger scale implementation of supporting homeless centres to aid smoking cessation
A spatial judgement task to determine background emotional state in laboratory rats (Rattus norvegicus)
Humans experiencing different background emotional states display contrasting cognitive (e.g. judgement) biases when responding to ambiguous stimuli. We have proposed that such biases may be used as indicators of animal emotional state. Here, we use a spatial judgement task, in which animals are trained to expect food in one location and not another, to determine whether rats in relatively positive or negative emotional states respond differently to ambiguous stimuli of intermediate spatial location. We housed 24 rats with environmental enrichment for seven weeks. Enrichment was removed for half the animals prior to the start of training (‘U’: unenriched) to induce a relatively negative emotional state, whilst being left in place for the remaining rats (‘E’: enriched). After six training days, the rats successfully discriminated between the rewarded and unrewarded locations in terms of an increased latency to arrive at the unrewarded location, with no housing treatment difference. The subjects then received three days of testing in which three ambiguous ‘probe’ locations, intermediate between the rewarded and unrewarded locations, were introduced. There was no difference between the treatments in the rats’ judgement of two out of the three probe locations, the exception being when the ambiguous probe was positioned closest to the unrewarded location. This result suggests that rats housed without enrichment, and in an assumed relatively negative emotional state, respond differently to an ambiguous stimulus compared to rats housed with enrichment, providing evidence that cognitive biases may be used to assess animal emotional state in a spatial judgement task
Multi-agent system for dynamic manufacturing system optimization
This paper deals with the application of multi-agent system concept for optimization of dynamic uncertain process. These problems are known to have a computationally demanding objective function, which could turn to be infeasible when large problems are considered. Therefore, fast approximations to the objective function are required. This paper employs bundle of intelligent systems algorithms tied together in a multi-agent system. In order to demonstrate the system, a metal reheat furnace scheduling problem is adopted for highly demanded optimization problem. The proposed multi-agent approach has been evaluated for different settings of the reheat furnace scheduling problem. Particle Swarm Optimization, Genetic Algorithm with different classic and advanced versions: GA with chromosome differentiation, Age GA, and Sexual GA, and finally a Mimetic GA, which is based on combining the GA as a global optimizer and the PSO as a local optimizer. Experimentation has been performed to validate the multi-agent system on the reheat furnace scheduling problem
The electronic-cigarette: effects on desire to smoke, withdrawal symptoms and cognition
Electronic cigarettes (e-cigarettes) are battery operated devices that deliver nicotine via inhaled vapour. Few studies have evaluated acute effects on craving and mood, and none have explored effects on cognition. This study aimed to explore the effects of the White Super e-cigarette on desire to smoke, nicotine withdrawal symptoms, attention and working memory. Eighty-six smokers were randomly allocated to either: 18mg nicotine e-cigarette (nicotine), 0mg e-cigarette (placebo), or just hold the e-cigarette (just hold) conditions. Participants rated their desire to smoke and withdrawal symptoms at baseline (T1), and five (T2) and twenty (T3) minutes after using the e-cigarette ad libitum for five minutes. A subset of participants completed the Letter Cancellation and Brown-Peterson Working Memory Tasks. After 20 minutes, compared with the just hold group, desire to smoke and some aspects of nicotine withdrawal were significantly reduced in the nicotine and placebo group; the nicotine e-cigarette was superior to placebo in males but not in females. The nicotine e-cigarette also improved working memory performance compared with placebo at the longer interference intervals. There was no effect of nicotine on Letter Cancellation performance. To conclude, the White Super e-cigarette alleviated desire to smoke and withdrawal symptoms 20 minutes after use although the nicotine content was more important for males. This study also demonstrated for the first time that the nicotine e-cigarette can enhance working memory performance. Further evaluation of the cognitive effects of the e-cigarette and its efficacy as a cessation tool is merited
A Memetic Analysis of a Phrase by Beethoven: Calvinian Perspectives on Similarity and Lexicon-Abstraction
This article discusses some general issues arising from the study of similarity in music, both human-conducted and computer-aided, and then progresses to a consideration of similarity relationships between patterns in a phrase by Beethoven, from the first movement of the Piano Sonata in A flat major op. 110 (1821), and various potential memetic precursors. This analysis is followed by a consideration of how the kinds of similarity identified in the Beethoven phrase might be understood in psychological/conceptual and then neurobiological terms, the latter by means of William Calvin’s Hexagonal Cloning Theory. This theory offers a mechanism for the operation of David Cope’s concept of the lexicon, conceived here as a museme allele-class. I conclude by attempting to correlate and map the various spaces within which memetic replication occurs
- …