110 research outputs found

    Drifting subpulses and inner acceleration regions in radio pulsars

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    The classical vacuum gap model of Ruderman & Sutherland, in which spark-associated subbeams of subpulse emission circulate around the magnetic axis due to the EB drift, provides a natural and plausible physical mechanism of the subpulse drift phenomenon. Recent progress in the analysis of drifting subpulses in pulsars has provided a strong support to this model by revealing a number of subbeams circulating around the magnetic axis in a manner compatible with theoretical predictions. However, a more detailed analysis revealed that the circulation speed in a pure vacuum gap is too high when compared with observations. Moreover, some pulsars demonstrate significant time variations of the drift rate, including a change of the apparent drift direction, which is obviously inconsistent with the EB drift scenario in a pure vacuum gap. We resolved these discrepancies by considering a partial flow of iron ions from the positively charged polar cap, coexisting with the production of outflowing electron-positron plasmas. By fitting the observationally deduced drift-rates to the theoretical values, we managed to estimate polar cap surface temperatures in a number of pulsars. The estimated surface temperatures correspond to a small charge depletion of the order of a few percent of the corotational charge density. We also argue that if the thermionic electron outflow from the surface of a negatively charged polar cap is slightly below the Goldreich-Julian density, then the resulting small charge depletion will have similar consequences as in the case of the ions outflow. We thus believe that the sparking discharge of a partially shielded acceleration potential drop occurs in all pulsars, with both positively (``pulsars'') and negatively (``anti-pulsars'') charged polar caps

    Predicting language learners' grades in the L1, L2, L3 and L4: the effect of some psychological and sociocognitive variables

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    This study of 89 Flemish high-school students' grades for L1 (Dutch), L2 (French), L3 (English) and L4 (German) investigates the effects of three higher-level personality dimensions (psychoticism, extraversion, neuroticism), one lower-level personality dimension (foreign language anxiety) and sociobiographical variables (gender, social class) on the participants' language grades. Analyses of variance revealed no significant effects of the higher-level personality dimensions on grades. Participants with high levels of foreign language anxiety obtained significantly lower grades in the L2 and L3. Gender and social class had no effect. Strong positive correlations between grades in the different languages could point to an underlying sociocognitive dimension. The implications of these findings are discussed

    The characteristics of millisecond pulsar emission: I. Spectra, pulse shapes and the beaming fraction

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    We have monitored a large sample of millisecond pulsars using the 100-m Effelsberg radio telescope in order to compare their radio emission properties to the slowly rotating population. With some notable exceptions, our findings suggest that the two groups of objects share many common properties. A comparison of the spectral indices between samples of normal and millisecond pulsars demonstrates that millisecond pulsar spectra are not significantly different from those of normal pulsars. There is evidence, however, that millisecond pulsars are slightly less luminous and less efficient radio emitters compared to normal pulsars. We confirm recent suggestions that a diversity exists among the luminosities of millisecond pulsars with the isolated millisecond pulsars being less luminous than the binary millisecond pulsars. There are indications that old millisecond pulsars exhibit somewhat flatter spectra than the presumably younger ones. We present evidence that millisecond pulsar profiles are only marginally more complex than those found among the normal pulsar population. Moreover, the development of the profiles with frequency is rather slow, suggesting very compact magnetospheres. The profile development seems to anti-correlate with the companion mass and the spin period, again suggesting that the amount of mass transfer in a binary system might directly influence the emission properties. The angular radius of radio beams of millisecond pulsars does not follow the scaling predicted from a canonical pulsar model which is applicable for normal pulsars. Instead they are systematically smaller. The smaller inferred luminosity and narrower emission beams will need to be considered in future calculations of the birth-rate of the Galactic population.Comment: 40 pages, 14 figures, accepted for publication in Ap

    Extent and correlates of self-reported exposure to tobacco advertising, promotion and sponsorship in smokers: Findings from the EUREST-PLUS ITC Europe Surveys

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    Introduction: Tobacco advertising, promotion and sponsorship (TAPS) are known to promote tobacco consumption and to discourage smoking cessation. Consequently, comprehensive TAPS bans are effective measures to reduce smoking. The objective of this study was to investigate to what extent smokers are exposed to TAPS in general, and in various media and localities, in different European countries. Methods: A cross-sectional analysis of national representative samples of adult smokers in 2016 from Germany, Greece, Hungary, Poland, Romania, and Spain (EUREST-PLUS Project, n=6011), as well as England (n=3503) and the Netherlands (n=1213) (ITC Europe Surveys) was conducted. Prevalence of self-reported TAPS exposure is reported by country, and socioeconomic correlates were investigated using logistic regression models. Results: Self-reported exposure to TAPS varied widely among the countries, from 15.4 % in Hungary to 69.2 % in the Netherlands. In most countries, tobacco advertising was most commonly seen at the point of sale, and rarely noticed in mass media. The multivariate analysis revealed some variation in exposure to TAPS by sociodemographic factors. Age showed the greatest consistency across countries with younger smokers (18–24 years) being more likely to notice TAPS than older smokers. Conclusions: TAPS exposure tended to be higher in countries with less restrictive regulation but was also reported in countries with more comprehensive bans, although at lower levels. The findings indicate the need for a comprehensive ban on TAPS to avoid a shift of marketing efforts to less regulated channels, and for stronger enforcement of existing bans

    Patterns of tobacco use, quit attempts, readiness to quit and self-efficacy among smokers with anxiety or depression: Findings among six countries of the EUREST-PLUS ITC Europe Surveys

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    Introduction: We compared smoking behaviors, past quit attempts, readiness to quit and beliefs about quitting among current cigarette smokers with probable anxiety or depression (PAD) to those without PAD, from six European Union (EU) Member States (MS). Methods: A nationally representative cross-sectional sample of 6011 adult cigarette smokers from six EU MS (Germany, Greece, Hungary, Poland, Romania, Spain) was randomly selected through a multistage cluster sampling design in 2016. Respondents were classified as having PAD based on self-reported current diagnosis or treatment for anxiety or depression, or a positive screen for major depression, according to a validated two-item instrument. Sociodemographic characteristics, patterns of tobacco use, past quitting, readiness to quit, self-efficacy and beliefs about quitting were assessed for patients with and without PAD. Logistic regression was used to examine predictors of PAD. All analyses were conducted using the complex samples package of SPSS. Results: Among smokers sampled, 21.0% (95% CI: 19.3–22.9) were identified as having PAD. Logistic regression analyses controlling for socioeconomic variables and cigarettes smoked per day found smokers with PAD were more likely to have made an attempt to quit smoking in the past (AOR=1.48; 95% CI: 1.25–1.74), made a quit attempt in the last 12 months (AOR=1.75; 95% CI: 1.45–2.11), and report lower self-efficacy with quitting (AOR=1.83; 95% CI: 1.44–2.32) compared to smokers without PAD. Additionally, it was found that individuals with PAD were more likely to report having received advice to quit from a doctor or health professional and having used quitline support as part of their last quit attempt. Conclusions: Smokers with PAD report a greater interest in quitting in the future and more frequent failed quit attempts than smokers without PAD; however, the high rates of untreated anxiety or depression, nicotine dependence, low confidence in the ability to quit, infrequent use of cessation methods, as well as socioeconomic factors may make quitting difficult

    Secondhand exposure to e-cigarette aerosols among smokers: A cross-sectional study in six European countries of the EUREST-PLUS ITC Europe Surveys

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    Introduction: Electronic cigarette (e-cigarette) use has grown significantly in some European Union (EU) Member States (MS). A better understanding of the exposure to secondhand e-cigarette aerosols (SHA) is necessary to develop and implement comprehensive regulations on e-cigarette use in public places. This study aims to assess the observation of e-cigarette use in public places, the self-reported exposure to SHA, and the level of users’ comfort using e-cigarettes in the presence of others. Methods: This is a cross-sectional study of the Wave 1 International Tobacco Control 6 European Countries Survey recruiting adult smokers (n=6011) across six EU MS: Germany, Greece, Hungary, Poland, Romania, and Spain, within the EURESTPLUS Project. A descriptive analysis was conducted to estimate the prevalence (%) of observed e-cigarette use in different places, frequency of self-reported exposure to SHA, and level of comfort using e-cigarettes in the presence of others. Results: In all, 31.0% of smokers observed others using e-cigarette in public places, 19.7% in indoor places where smoking is banned, and 14.5% indoors at work. Almost 37% of smokers reported to be ever exposed to SHA, ranging from 17.7% in Spain to 63.3% in Greece. The higher prevalence of observed e-cigarette use and passive exposure to SHA was reported by smokers of younger age, of higher educational level and those being current or former e-cigarette users. Part (8.8%) of the smokers who were also e-cigarette users reported feeling uncomfortable using e-cigarettes in the presence of others. Conclusions: A third of smokers from six EU MS reported being exposed to SHA. Prevalence differences were observed among the countries. In the context of scarce evidence on long-term health effects of exposure to SHA, precautionary regulations protecting bystanders from involuntary exposure should be developed

    Smoking in public places in six European countries: Findings from the EUREST-PLUS ITC Europe Survey

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    Introduction: Surveillance of tobacco consumption in public places is an important measure to evaluate the impact of tobacco control interventions over time. The objective of this study was to estimate the prevalence of smoking as seen by smokers and their smoking behaviour in public places, in six European countries. Methods: We used baseline data of the International Tobacco Control Six European countries (ITC 6E) Survey, part of the EUREST-PLUS Project, conducted in 2016 in national representative samples of about 1000 adult smokers aged 18 years and older in Germany, Greece, Hungary, Poland, Romania and Spain. For each setting (workplaces, restaurants, bars/pubs and discos) participants were asked whether they had seen someone smoking during their last visit there and whether they too had smoked there. We report the overall and by-country weighted prevalence of seeing someone smoking and the smokers’ own smoking behaviour at each setting. We also assess the relationship between seeing someone smoking and smoking themselves at these settings. Results: The prevalence of smoking as seen by smokers was 18.8% at workplaces, with high variability among countries (from 4.7% in Hungary to 40.8% in Greece). Among smokers visiting leisure facilities in the last year, during their last visit 22.7% had seen someone smoking inside restaurants and 12.2% had smoked themselves there, while for bars/pubs the corresponding prevalences were 33.9% and 20.4%, and inside discos 44.8% and 34.8%. Conclusions: Smoking is still prevalent at leisure facilities, particularly at discos in Europe, with high variability among countries. More extensive awareness campaigns and stricter enforcement are needed to increase the compliance of smokefree regulations, especially in leisure facilities
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