2,598 research outputs found

    The Association of Cigarette Smoking with Depression and Anxiety:A Systematic Review

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    BACKGROUND: Many studies report a positive association between smoking and mental illness. However, the literature remains mixed regarding the direction of this association. We therefore conducted a systematic review evaluating the association of smoking and depression and/or anxiety in longitudinal studies. METHODS: Studies were identified by searching PubMed, Scopus, and Web of Science and were included if they: (1) used human participants, (2) were longitudinal, (3) reported primary data, (4) had smoking as an exposure and depression and/or anxiety as an outcome, or (5) had depression and/or anxiety as the exposure and smoking as an outcome. RESULTS: Outcomes from 148 studies were categorized into: smoking onset, smoking status, smoking heaviness, tobacco dependence, and smoking trajectory. The results for each category varied substantially, with evidence for positive associations in both directions (smoking to later mental health and mental health to later smoking) as well as null findings. Overall, nearly half the studies reported that baseline depression/anxiety was associated with some type of later smoking behavior, while over a third found evidence that a smoking exposure was associated with later depression/anxiety. However, there were few studies directly supporting a bidirectional model of smoking and anxiety, and very few studies reporting null results. CONCLUSIONS: The literature on the prospective association between smoking and depression and anxiety is inconsistent in terms of the direction of association most strongly supported. This suggests the need for future studies that employ different methodologies, such as Mendelian randomization (MR), which will allow us to draw stronger causal inferences. IMPLICATIONS: We systematically reviewed longitudinal studies on the association of different aspects of smoking behavior with depression and anxiety. The results varied considerably, with evidence for smoking both associated with subsequent depression and anxiety, and vice versa. Few studies supported a bidirectional relationship, or reported null results, and no clear patterns by gender, ethnicity, clinical status, length to follow-up, or diagnostic test. Suggesting that despite advantages of longitudinal studies, they cannot alone provide strong evidence of causality. Therefore, future studies investigating this association should employ different methods allowing for stronger causal inferences to be made, such as MR

    The use of cosmic muons in detecting heterogeneities in large volumes

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    The muon intensity attenuation method to detect heterogeneities in large matter volumes is analyzed. Approximate analytical expressions to estimate the collection time and the signal to noise ratio, are proposed and validated by Monte Carlo simulations. Important parameters, including point spread function and coordinate reconstruction uncertainty are also estimated using Monte Carlo simulations.Comment: 8 pages, 11 figures, submetted to NIM

    The development and validation of a human screening model of tobacco abstinence

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    Introduction Given the low efficacy of smoking cessation methods, an experimental medicine model indicating smoking abstinence would be of great benefit to the development of new treatments. Hence the sensitivity of cognitive tasks and ambulatory craving measures to smoking abstinence were investigated. Methods Cognitive tasks and ambulatory ratings of craving were assessed for sensitivity to acute abstinence (experiment 1), and nicotine replacement therapy administration (NRT) (experiment 2). Results In experiment 1 go/no-go performance was improved (Mean Difference [MD] -0.99, 95% CI: −1.90 to −0.08) and craving was lower (Regression Coefficient [RC] −33.39, 95% CI: -39.96 to -26.82) in satiated compared with abstinent smokers. There was no clear evidence that N-back (MD 0.64, 95% CI: −0.42 to 2.51), delay discounting (MD 0.01, 95% CI: 0.001 to 0.005) or dot probe performance (MD 0.61, 95% CI: −0.87 to 1.54) were sensitive to acute abstinence. In experiment 2 go/no-go performance was improved (MD 1.12, 95% CI: 0.16–2.08) and craving was lower (RC −18.59, 95% CI: −24.63 to −12.55) smokers abstinent overnight receiving NRT compared with placebo. There was no clear evidence that N-back (MD −0.25, 95% CI: −1.45 to 0.94), delay discounting (MD 0.01, 95% CI: -0.002 to 0.004) or dot probe performance (MD −0.49, 95% CI: −1.61 to −0.64) were sensitive to NRT. Conclusions Findings from two experiments converge to suggest that abstinence in smokers reliably increases ambulatory craving assessments and, to a lesser extent, decreases go/no-go task performance. These findings can be utilized in the development of an experimental medicine model to test novel treatments for smoking cessation

    Behavioral tasks sensitive to acute abstinence and predictive of smoking cessation success:a systematic review and meta-analysis

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    BACKGROUND AND AIMS: Performance on cognitive tasks may be sensitive to acute smoking abstinence and may also predict whether quit attempts fail. Our aim was to conduct a systematic review and meta-analysis to identify cognitive tasks sensitive to acute abstinence and predictive of smoking cessation success.METHODS: Embase, Medline, PsycInfo and Web of Science were searched up to March 2016. Studies were included if they enrolled adults and assessed smoking using used a quantitative measure. Studies were combined in a random effects meta-analysis.RESULTS: We included 42 acute abstinence studies and 13 cessation studies were included. There was evidence for an effect of abstinence on delay discounting [d = 0.26, 95% CI 0.07 to 0.45, p = 0.005], response inhibition [d = 0.48, 95% CI 0.26 to 0.70, p &lt; 0.001], mental arithmetic [d = 0.38, 95% CI 0.06 to 0.70, p = 0.018], and recognition memory [d = 0.46, 95% CI 0.23 to 0.70, p &lt; 0.001]. In contrast performance on the Stroop [d =0 .17, 95% CI -0.17 to 0.51, p = 0.333] and smoking Stroop [d = 0.03, 95% CI -0.11 to 0.17, p = 0.675] task was not influenced by abstinence. We found only weak evidence for an effect of acute abstinence on dot probe task performance [d = 0.15, 95% CI -0.01 to 0.32, p = 0.072]. The design of the cessation studies was too heterogeneous to permit meta-analysis.CONCLUSIONS: Compared with satiated smokers, acutely abstinent smokers display higher delay discounting, lower response inhibition, impaired arithmetic, and recognition memory performance. However, reaction time measures of cognitive bias appear to be unaffected by acute tobacco abstinence. Conclusions about cognitive tasks that predict smoking cessation success were limited by methodological inconsistencies.</p

    Measurement of the Cross Section Asymmetry of the Reaction gp-->pi0p in the Resonance Energy Region Eg = 0.5 - 1.1 GeV

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    The cross section asymmetry Sigma has been measured for the photoproduction of pi0-mesons off protons, using polarized photons in the energy range Eg = 0.5 - 1.1 GeV. The CM angular coverage is Theta = 85 - 125 deg with energy and angle steps of 25 MeV and 5 deg, respectively. The obtained Sigma data, which cover the second and third resonance regions, are compared with existing experimental data and recent phenomenological analyses. The influence of these measurements on such analyses is also considered

    MONTE CARLO SIMULATIONS OF SYNCHROTON RADIATION AND VACUUM PERFORMANCE OF THE MAX IV LIGHT SOURCE

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    Abstract In the 3 GeV ring of MAX IV light source in Lund, Sweden, the intense synchrotron radiation (SR) distributed along the ring generates important thermal and vacuum effects. By means of a Monte Carlo simulation package, which is currently developed at CERN, both thermal and vacuum effects are quantitatively analysed, in particular near the crotch absorbers and the surrounding NEG-coated vacuum chambers. Using SynRad+, the beam trajectory of the upstream bending magnet is calculated; SR photons are generated and traced through the geometry until their absorption. This allows an analysis of the incident power density on the absorber, and to calculate the photon induced outgassing. The results are imported to Molflow+, a Monte Carlo vacuum simulator that works in the molecular flow regime, and the pressure in the vacuum system and the saturation length of the NEG coating are determined using iterations
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