35 research outputs found

    Stochastic Volterra equations with H\"older diffusion coefficients

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    The existence of strong solutions and pathwise uniqueness are established for stochastic Volterra equations with H\"older continuous diffusion coefficients and sufficiently regular kernels. Moreover, we study the sample path regularity, the integrability and the semimartingale property of solutions to stochastic Volterra equations.Comment: 23 page

    On the existence of weak solutions to stochastic Volterra equations

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    The existence of weak solutions is established for stochastic Volterra equations with time-inhomogeneous coefficients allowing for general kernels in the drift and convolutional or bounded kernels in the diffusion term. The presented approach is based on a newly formulated local martingale problem associated to stochastic Volterra equations.Comment: 13 page

    Event-related desynchronization in motor imagery with EEG neurofeedback in the context of declarative interference and sleep

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    Motor imagery (MI) in combination with neurofeedback (NF) is a promising supplement to facilitate the acquisition of motor abilities and the recovery of impaired motor abilities following brain injuries. However, the ability to control MI NF is subject to a wide range of inter-individual variability. A substantial number of users experience difficulties in achieving good results, which compromises their chances to benefit from MI NF in a learning or rehabilitation context. It has been suggested that context factors, that is, factors outside the actual motor task, can explain individual differences in motor skill acquisition. Retrospective declarative interference and sleep have already been identified as critical factors for motor execution (ME) and MI based practice. Here, we investigate whether these findings generalize to practicing MI NF. Three groups underwent three blocks of practicing MI with NF, each on two subsequent days. In two of the groups, MI NF blocks were followed by either immediate or delayed declarative memory tasks. The control group performed only MI NF and no specific interference tasks. Two of the MI NF blocks were run on the first day of the experiment, the third in the morning of the second day. Significant within-block NF gains in mu and beta frequency event-related desynchronization (ERD) where evident for all groups. However, data did not provide evidence for an impact of immediate or delayed declarative interference on MI NF ERD. Also, MI NF ERD remained unchanged after a night of sleep. We did not observe the expected pattern of results for MI NF ERD with regard to declarative interference and a night of sleep. This is discussed in the context of variable experimental task designs, inter-individual differences, and performance measures

    "I did not intend to stop. I just could not stand cigarettes any more." A qualitative interview study of smoking cessation among the elderly

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    <p>Abstract</p> <p>Background</p> <p>Every year, more than 650,000 Europeans die because they smoke. Smoking is considered to be the single most preventable factor influencing health. General practitioners (GP) are encouraged to advise on smoking cessation at all suitable consultations. Unsolicited advice from GPs results in one of 40-60 smokers stopping smoking. Smoking cessation advice has traditionally been given on an individual basis. Our aim was to gain insights that may help general practitioners understand why people smoke, and why smokers stop and then remain quitting and, from this, to find fruitful approaches to the dialogue about stopping smoking.</p> <p>Methods</p> <p>Interviews with 18 elderly smokers and ex-smokers about their smoking and decisions to smoke or quit were analysed with qualitative content analysis across narratives. A narrative perspective was applied.</p> <p>Results</p> <p>Six stages in the smoking story emerged, from the start of smoking, where friends had a huge influence, until maintenance of the possible cessation. The informants were influenced by "all the others" at all stages. Spouses had vital influence in stopping, relapses and continued smoking. The majority of quitters had stopped by themselves without medication, and had kept the tobacco handy for 3-6 months. Often smoking cessation seemed to happen unplanned, though sometimes it was planned. With an increasingly negative social attitude towards smoking, the informants became more aware of the risks of smoking.</p> <p>Conclusion</p> <p>"All the others" is a clue in the smoking story. For smoking cessation, it is essential to be aware of the influence of friends and family members, especially a spouse. People may stop smoking unplanned, even when motivation is not obvious. Information from the community and from doctors on the negative aspects of smoking should continue. Eliciting life-long smoking narratives may open up for a fruitful dialogue, as well as prompting reflection about smoking and adding to the motivation to stop.</p

    The Case against a Smoker's License

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    Tobacco continues to kill millions of people around the world each year and its use is increasing in some countries, which makes the need for new, creative, and radical efforts to achieve the tobacco control endgame vitally important. One such effort is discussed in this PLOS Medicine Debate, where Simon Chapman presents his proposal for a "smoker's license" and Jeff Collin argues against. Chapman sets out a case for introducing a smart card license for smokers designed to limit access to tobacco products and encourage cessation. Key elements of the smoker's license include smokers setting daily limits, financial incentives for permanent license surrender, and a test of health risk knowledge for commencing smokers. Collin argues against the proposal, saying that it would shift focus away from the real vector of the epidemic--the tobacco industry--and that by focusing on individuals it would censure victims, increase stigmatization of smokers, and marginalize the poor

    Creating symbolic cultures of consumption: an analysis of the content of sports wagering advertisements in Australia

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    Background: Since 2008, Australia has seen the rapid emergence of marketing for online and mobile sports wagering. Previous research from other areas of public health, such as tobacco and alcohol, has identified the range of appeal strategies these industries used to align their products with culturally valued symbols. However, there is very limited research that has investigated the tactics the sports wagering industry uses within marketing to influence the consumption of its products and services. Method: This study consisted of a mixed method interpretive content analysis of 85 sports wagering advertisements from 11 Australian and multinational wagering companies. Advertisements were identified via internet searches and industry websites. A coding framework was applied to investigate the extent and nature of symbolic appeal strategies within advertisements. Results: Ten major appeal strategies emerged from this analysis. These included sports fan rituals and behaviours; mateship; gender stereotypes; winning; social status; adventure, thrill and risk; happiness; sexualised imagery; power and control; and patriotism. Symbols relating to sports fan rituals and behaviours, and mateship, were the most common strategies used within the advertisements. Discussion/Conclusions: This research suggests that the appeal strategies used by the sports wagering industry are similar to those strategies adopted by other unhealthy commodity industries. With respect to gambling, analysis revealed that strategies are clearly targeted to young male sports fans. Researchers and public health practitioners should seek to better understand the impact of marketing on the normalisation of sports wagering for this audience segment, and implement strategies to prevent gambling harm

    Conversions of cognitive screenings. Mini-Mental State Examination vs. Montreal Cognitive Assessment vs. DemTect

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    Background: For acomprehensive specification and quantification of neuropsychological deficits, extensive neuropsychological assessment is needed. Due to its time intensiveness, this cannot be accomplished in every clinical setting and is not always necessary. Therefore, screening instruments provide a first step. Because the selection differs between and sometimes even within clinics, a comparison of results for different screening procedures would be helpful. The current study aimed at achieving this in the German-speaking area, i.e. conversions between sum scores of the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA) and Dementia Detection Test (DemTect) can be accomplished. Method: In the Department of Neurology at the University Hospital of Cologne, 8240 patients with different neurological diseases were examined between 2008 and 2017. Conversion scores using the results in the MMSE, MoCA and DemTect were computed by using the equipercentile equating method. Results: The calculated bidirectional conversion tables enable a quick and easy comparison between the three most commonly used screening instruments. They are also similar to those from previous studies in English-speaking countries. Conclusion: The results enable an enhanced longitudinal assessment of cognitive functions in different clinical settings, provide comparability, and offer more flexibility for determination of patient status. An extension of the current study might be the transfer of the method presented to other cognitive or affective domains, such as memory and depression
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