226 research outputs found

    The r'-band luminosity function of Abell1367: a comparison with Coma

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    We made a large (approximately 1degr x 1degr) r'-band imaging survey of the central regions of the two nearby clusters of galaxies, Abell1367 and Coma. The data, presented as a catalog, are used to construct the r'-band luminosity function (LF) of galaxies in these two clusters, by subtracting the Yasuda et al. (2001) galaxy counts from our cluster counts. Our Coma luminosity function is consistent with previous determinations, i.e. providing a faint end slope alpha = -1.47_-0.09^+0.08, significantly steeper than the one we find for Abell1367 (alpha = -1.07_-0.16^+0.20). The counts in Abell1367 show a relative minimum at r' ~ 19, followed by a steep increase faintward. The difference between the two clusters appears significant, given the consistency of the experimental conditions in the two clusters. Whereas for Coma we find a significant increase of the slope of the LF outwards, no such effect is found for Abell1367.Comment: 12 pages, 8 figures, accepted for publication in A&

    The Extraordinary `Superthin' Spiral Galaxy UGC7321. I. Disk Color Gradients and Global Properties from Multiwavelength Observations

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    We present B- and R-band imaging and photometry, H-alpha narrow-band imaging, NIR H-band imaging, and HI 21-cm spectroscopy of the nearby Sd spiral galaxy UGC7321. UGC7321 exhibits a remarkably thin stellar disk with no bulge component. The galaxy has a very diffuse, low surface brightness disk, which appears to suffer little internal extinction in spite of its edge-on geometry. The UGC7321 disk shows significant B-R color gradients in both the radial and vertical directions. These color gradients cannot be explained solely by dust and are indicative of changes in the mix of stellar ages and/or metallicity as a function of both radius and height above the galaxy plane. The outer regions of the UGC7321 disk are too blue to be explained by low metallicity alone (B-R<0.6), and must be relatively young. However, the galaxy also contains stellar populations with B-R>1.1, indicating it is not a young or recently-formed galaxy. The disk of UGC7321 is not a simple exponential, but exhibits a light excess at small radii, as well as distinct surface brightness zones. Together the properties of UGC7321 imply that it is an under-evolved galaxy in both a dynamical and in a star-formation sense. (Abridged)Comment: Accepted to the Astronomical Journal; 28 pages, 1 table and 21 figures (GIF and postscript

    Relative luminosity measurement of the LHC with the ATLAS forward calorimeter

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    In this paper it is shown that a measurement of the relative luminosity changes at the LHC may be obtained by analysing the currents drawn from the high voltage power supplies of the electromagnetic section of the forward calorimeter of the ATLAS detector. The method was verified with a reproduction of a small section of the ATLAS forward calorimeter using proton beams of known beam energies and variable intensities at the U-70 accelerator at IHEP in Protvino, Russia. The experimental setup and the data taking during a test beam run in April 2008 are described in detail. A comparison of the measured high voltage currents with reference measurements from beam intensity monitors shows a linear dependence on the beam intensity. The non-linearities are measured to be less than 0.5 % combining statistical and systematic uncertainties.Comment: 16 page

    The effectiveness of interventions to change six health behaviours: a review of reviews

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    Background: Several World Health Organisation reports over recent years have highlighted the high incidence of chronic diseases such as diabetes, coronary heart disease and cancer. Contributory factors include unhealthy diets, alcohol and tobacco use and sedentary lifestyles. This paper reports the findings of a review of reviews of behavioural change interventions to reduce unhealthy behaviours or promote healthy behaviours. We included six different health-related behaviours in the review: healthy eating, physical exercise, smoking, alcohol misuse, sexual risk taking (in young people) and illicit drug use. We excluded reviews which focussed on pharmacological treatments or those which required intensive treatments (e. g. for drug or alcohol dependency). Methods: The Cochrane Library, Database of Abstracts of Reviews of Effectiveness (DARE) and several Ovid databases were searched for systematic reviews of interventions for the six behaviours (updated search 2008). Two reviewers applied the inclusion criteria, extracted data and assessed the quality of the reviews. The results were discussed in a narrative synthesis. Results: We included 103 reviews published between 1995 and 2008. The focus of interventions varied, but those targeting specific individuals were generally designed to change an existing behaviour (e. g. cigarette smoking, alcohol misuse), whilst those aimed at the general population or groups such as school children were designed to promote positive behaviours (e. g. healthy eating). Almost 50% (n = 48) of the reviews focussed on smoking (either prevention or cessation). Interventions that were most effective across a range of health behaviours included physician advice or individual counselling, and workplace- and school-based activities. Mass media campaigns and legislative interventions also showed small to moderate effects in changing health behaviours. Generally, the evidence related to short-term effects rather than sustained/longer-term impact and there was a relative lack of evidence on how best to address inequalities. Conclusions: Despite limitations of the review of reviews approach, it is encouraging that there are interventions that are effective in achieving behavioural change. Further emphasis in both primary studies and secondary analysis (e.g. systematic reviews) should be placed on assessing the differential effectiveness of interventions across different population subgroups to ensure that health inequalities are addressed.</p

    Methods of a national colorectal cancer cohort study: the PIPER Project

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    A national study looking at bowel cancer in New Zealand has previously been completed (the PIPER Project). The study included 5,610 patients and collected medical information about how each person was found to have bowel cancer and the treatment they received. This paper reports how the study was carried out. The information collected in the study will be used to look at the quality of care being provided to New Zealand patients with bowel cancer, and to find out if differences in care occur based on where people live, their ethnicity and their socioeconomic status

    Barriers to the provision of smoking cessation assistance:A qualitative study among Romanian family physicians

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    BACKGROUND: Smoking cessation is the most effective intervention to prevent and slow down the progression of several respiratory and other diseases and improve patient outcomes. Romania has legislation and a national tobacco control programme in line with the World Health Organization Framework for Tobacco Control. However, few smokers are advised to quit by their family physicians (FPs). AIM: To identify and explore the perceived barriers that prevent Romanian FPs from engaging in smoking cessation with patients. METHODS: A qualitative study was undertaken. A total of 41 FPs were recruited purposively from Bucharest and rural areas within 600 km of the city. Ten FPs took part in a focus group and 31 participated in semistructured interviews. Analysis was descriptive, inductive and themed, according to the barriers experienced. RESULTS: Five main barriers were identified: limited perceived role for FPs; lack of time during consultations; past experience and presence of disincentives; patients' inability to afford medication; and lack of training in smoking cessation skills. Overarching these specific barriers were key themes of a medical and societal hierarchy, which undermined the FP role, stretched resources and constrained care. CONCLUSIONS: Many of the barriers described by the Romanian FPs reflected universally recognised challenges to the provision of smoking cessation advice. The context of a relatively hierarchical health-care system and limitations of time and resources exacerbated many of the problems and created new barriers that will need to be addressed if Romania is to achieve the aims of its National Programme Against Tobacco Consumption

    Academic reading format preferences and behaviors among university students worldwide: A comparative survey analysis

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    This study reports the descriptive and inferential statistical findings of a survey of academic reading format preferences and behaviors of 10,293 tertiary students worldwide. The study hypothesized that country-based differences in schooling systems, socioeconomic development, culture or other factors might have an influence on preferred formats, print or electronic, for academic reading, as well as the learning engagement behaviors of students. The main findings are that country of origin has little to no relationship with or effect on reading format preferences of university students, and that the broad majority of students worldwide prefer to read academic course materials in print. The majority of participants report better focus and retention of information presented in print formats, and more frequently prefer print for longer texts. Additional demographic and post-hoc analysis suggests that format preference has a small relationship with academic rank. The relationship between task demands, format preferences and reading comprehension are discussed. Additional outcomes and implications for the fields of education, psychology, computer science, information science and human-computer interaction are considered
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