1,723,694 research outputs found
Diagnosis-specific sickness absence as a predictor of mortality: the Whitehall II prospective cohort study
No full textObjective To investigate whether knowing the diagnosis for sickness absence improves prediction of mortality.Design Prospective cohort study established in 1985- 8. Sickness absence records including diagnoses were obtained from computerised registers.Setting 20 civil service departments in London.Participants 6478 civil servants aged 35- 55 years.Main outcome measures All cause, cardiovascular, and cancer mortality until 2004, average follow- up 13 years.Results After adjustment for age, sex, and employment grade, employees who had one or more medically certified spells of sickness absence (> 7 days) in a three year period had a mortality 1.7 ( 95% CI 1.3 to 2.1) times greater than those with no medically certified spells. Inclusion of diagnoses improved the prediction of all cause mortality ( P= 0.03). The hazard ratio for mortality was 4.7 ( 2.6 to 8.5) for absences with circulatory disease diagnoses, 2.2 ( 1.4 to 3.3) for surgical operations, and 1.9 ( 1.2 to 3.1) for psychiatric diagnoses. Psychiatric absences were also predictive of cancer mortality ( 2.5 ( 1.3 to 4.7)). Associations of infectious, respiratory, and injury absences with overall mortality were less marked ( hazard ratios from 1.5 to 1.7), and there was no association between musculoskeletal absences and mortality.Conclusions Major diagnoses for medically certified absences were associated with increased mortality, with the exception of musculoskeletal disease. Data on sickness absence diagnoses may provide useful information to identify groups with increased health risk and a need for targeted interventions
A study of the physical properties of an active asteroid (6478 Gault)
Get PDFIn 2019 January, the appearance of asteroid 6478 Gault immediately attracted attention because this object exhibited a long and thin tail that was quite different from the usual asteroids. This unexpected morphology placed asteroid 6478 Gault into the catalogue of active asteroids. We acquired photometric and spectroscopic observations on 37 nights from 2019 January to April using several telescopes, including LOT (1 m telescope) and SLT (40 cm telescope) at Lulin Observatory, and the 2.4 m telescope at Lijiang station of Yunnan Observatory. We did not find any reliable value for the rotational period of Gault during 2.5 hr and 5 hr observations on 2019 January 26 at Lijiang station and March 25 at Lulin Observatory, respectively. We classified 6478 Gault as a Q-type asteroid using visible spectrum and photometric measurements, including colors and relative reflectance. By using Finson-Probstein analysis, the grain size for Gault's tail 2 is larger than 20 um
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dust properties of double-tailed active asteroid (6478) Gault
Get PDFpeer reviewedContext. Asteroid (6478) Gault was discovered to exhibit a comet-like tail in observations from December 2018, becoming a new member of the so-called active asteroid population in the main asteroid belt. Aims: We seek to investigate the grain properties of the dust ejected from asteroid (6478) Gault and to give insight into the activity mechanism(s). Methods: We use a Monte Carlo dust tail brightness code to retrieve the dates of dust ejection, the physical properties of the grains, and the total dust mass losses during each event. The code takes into account the brightness contribution of the asteroid itself. The model is applied to a large data set of images spanning the period from 2019 January 11 to 2019 March 13. In addition, we carried out both short- and long-term photometric measurements of the asteroid. Results: It is shown that, to date, asteroid (6478) Gault has experienced two episodes of impulsive dust ejection, which took place around 2018 November 5 and 2019 January 2. These two episodes released at least 1.4 × 10[SUP]7[/SUP] kg and 1.6 × 10[SUP]6[/SUP] kg of dust, respectively, at escape speeds. The size distribution, consisting of particles in the 1 μm-1 cm radius range, follows a broken power law with bending points near 15 μm and 870 μm. On the other hand, the photometric series indicate a nearly constant magnitude over several 5-7.3 h periods, which is a possible effect of the masking of a rotational light curve by the dust. Conclusions: The dust particles forming Gault's tails were released from the asteroid at escape speeds, but the specific ejection mechanism is unclear until photometry of the dust-free asteroid are conducted to assess whether this was related to rotational disruption or to other possible causes
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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