1,408 research outputs found
Unintegrated parton distributions and inclusive jet production at HERA
We describe how unintegrated parton distributions can be calculated from
conventional integrated distributions. We extend and improve the 'last-step'
evolution approach, and explain why doubly-unintegrated parton distributions
are necessary. We generalise k_t-factorisation to (z,k_t)-factorisation. We
apply the formalism to inclusive jet production in deep-inelastic scattering,
mainly at leading-order, but we also study the extension to next-to-leading
order. We compare the predictions with recent HERA data.Comment: 32 pages, 11 figures. Version to appear in Eur. Phys. J.
Automatic assembly design project 1968/69: report of the control and motivation committee
Methods of control for automatic assembly machines are
surveyed. The control requirements of the versatile
automatic assembly machine are analysed, and the most
practical system is specified and designed in detail
Production values as program quality signals in Spanish linear TV: A comparison of two periods
Technology disruption, digitalization and media convergence have triggered a profound crisis in the television industry. In this context, quality is an essential strategic element for success, especially when consumers have learned through their experience with VOD, becoming more demanding and less loyal customers. Then, has the importance of quality signals changed with the emergence of new online alternatives? And the quality perception among viewers? Our research explores four production values (the host, content, the set, and technical quality) as TV program quality signals and their effect on the quality perception of entertainment programs of Spanish broadcasters. We compare two years: 2012 and 2016, a period during which the Spanish television market changed due to appearance of OTT services. Using t-tests and regression models, we establish that the importance of quality signals varied over this period, with content proving more important and the set less so in 2016 as compared with 2012. Additionally, in 2016, the results show that the quality perception of linear TV entertainment programs depended more on subjective elements such as liking and satisfaction than on objective elements, as it was in 2012. Finally, our findings are discussed, and some managerial implications and future research are suggested
Development and Testing of Relative Risk-based Health Messages for Electronic Cigarette Products
Background: Health messages on e-cigarette packs emphasise nicotine addiction or harms using similar wording to warnings on cigarette packs. These may not be appropriate for e-cigarettes which constitute a reduced risk alternative for smokers. This research aimed to i) develop and test a selection of relative risk messages for e-cigarette products; ii) compare these to the two current EU Tobacco Products Directive (TPD) nicotine addiction messages; and iii) explore differences between smokers, non-smokers and dual users.
Method: Twenty-six messages focusing on either harm-reduction or cessation were developed and rated by multidisciplinary experts for accuracy, persuasiveness and clarity. The eight highest ranking messages were compared alongside the TPD messages in a sample of 983 European residents (316 smokers, 327 non-smokers, 340 dual users) on understandability, believability and convincingness.
Results: On all three constructs combined, the two TPD messages rated the highest, closely followed by four relative risk messages “Completely switching to e-cigarettes lowers your risk of smoking related diseases”, “Use of this product is much less harmful than smoking”, “Completely switching to e-cigarettes is a healthier alternative to smoking”, and “This product presents substantially lower risks to health than cigarettes” which did not differ statistically from the TPD messages. Non-smokers rated TPD1 significantly higher overall than dual users. Dual users rated “This product is a safer alternative to smoking” significantly higher than non-smokers. Messages did not differ on understandability.
Conclusions: These alternative messages provide a useful resource for future research and for policy makers considering updating e-cigarette product labelling
Development and Testing of Relative Risk-based Health Messages for Electronic Cigarette Products
Background:
Health messages on e-cigarette packs emphasise nicotine addiction or harms using similar wording to warnings on cigarette packs. These may not be appropriate for e-cigarettes which constitute a reduced risk alternative for smokers. This research aimed to (1) develop and test a selection of relative risk messages for e-cigarette products; (2) compare these to the two current EU Tobacco Products Directive (TPD) nicotine addiction messages; and (3) explore differences between smokers, non-smokers and dual users.
Method:
Twenty-six messages focusing on either harm-reduction or cessation were developed and rated by multidisciplinary experts for accuracy, persuasiveness and clarity. The eight highest ranking messages were compared alongside the TPD messages in a sample of 983 European residents (316 smokers, 327 non-smokers, 340 dual users) on understandability, believability and convincingness.
Results:
On all three constructs combined, the two TPD messages rated the highest, closely followed by four relative risk messages “Completely switching to e-cigarettes lowers your risk of smoking related diseases”, “Use of this product is much less harmful than smoking”, “Completely switching to e-cigarettes is a healthier alternative to smoking”, and “This product presents substantially lower risks to health than cigarettes” which did not differ statistically from the TPD messages. Non-smokers rated TPD1 significantly higher overall than dual users. Dual users rated “This product is a safer alternative to smoking” significantly higher than non-smokers. Messages did not differ on understandability.
Conclusions:
These alternative messages provide a useful resource for future research and for policy makers considering updating e-cigarette product labelling
The unintegrated gluon distribution from the CCFM equation
The gluon distribution f(x, k_t^2,mu^2), unintegrated over the transverse
momentum k_t of the gluon, satisfies the angular-ordered CCFM equation which
interlocks the dependence on the scale k_t with the scale \mu of the probe. We
show how, to leading logarithmic accuracy, the equation can be simplified to a
single scale problem. In particular we demonstrate how to determine the
two-scale unintegrated distribution f(x,k_t^2,mu^2) from knowledge of the
integrated gluon obtained from a unified scheme embodying both BFKL and DGLAP
evolution.Comment: 16 pages LaTeX, 3 eps figure
Perceptions of neighborhood social environment and drug dependence among incarcerated women and men: a cross-sectional analysis
Abstract
Background
Perception of neighborhood social environment can influence an individual’s susceptibility to drug dependence. However, this has never been examined with a jailed sample, where frequent transitions between local jails and disadvantaged neighborhoods are common. Understanding these associations could aid in the design of targeted programs to decrease drug dependence and recidivism among the incarcerated.
Methods
For this study, 596 women and men from three Kansas City jails were surveyed over the course of six months in 2010. Drug dependence was assessed with DSM-IV criteria. Independent variables included fear of one’s neighborhood, perceived level of neighborhood violence, and social capital. All data were self-reported and were analyzed using logistic regression.
Results
Controlling for gender and age, fear of neighborhood violence was associated with increased odds of having drug dependence (OR = 1.27, CI 1.02, 1.58) and a higher level of social capital prior to incarceration was associated with lower odds of drug dependence (OR = 0.65, CI 0.44, 0.96). Mental health problem diagnosis and past year intimate partner violence were significant mediating factors. Gender and race/ethnicity were significant moderating factors between neighborhood disadvantage and drug dependence.
Conclusions
Our study suggests that drug dependence programs for women and men who cycle between jails and communities require both individual- and community-level interventions. To be most effective, programs at the community-level should focus on helping specific groups navigate their communities, as well as address individual health needs associated with drug dependence.Peer Reviewe
E‐cigarette support for smoking cessation: Identifying the effectiveness of intervention components in an on‐line randomized optimization experiment
Aims, Design and Setting
The aim of this study was to determine which combination(s) of five e-cigarette-orientated intervention components, delivered on-line, affect smoking cessation. An on-line (UK) balanced five-factor (2 × 2 × 2 × 2 × 2 = 32 intervention combinations) randomized factorial design guided by the multi-phase optimization strategy (MOST) was used.
Participants
A total of 1214 eligible participants (61% female; 97% white) were recruited via social media.
Interventions
The five on-line intervention components designed to help smokers switch to exclusive e-cigarette use were: (1) tailored device selection advice; (2) tailored e-liquid nicotine strength advice; (3): tailored e-liquid flavour advice; (4) brief information on relative harms; and (5) text message (SMS) support.
Measurements
The primary outcome was 4-week self-reported complete abstinence at 12 weeks post-randomization. Primary analyses were intention-to-treat (loss to follow-up recorded as smoking). Logistic regressions modelled the three- and two-way interactions and main effects, explored in that order.
Findings
In the adjusted model the only significant interaction was a two-way interaction, advice on flavour combined with text message support, which increased the odds of abstinence (odds ratio = 1.55, 95% confidence interval = 1.13–2.14, P = 0.007, Bayes factor = 7.25). There were no main effects of the intervention components.
Conclusions
Text-message support with tailored advice on flavour is a promising intervention combination for smokers using an e-cigarette in a quit attempt
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