1,720,994 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Exposure to low levels of hydrogen sulphide and its impact on chronic obstructive pulmonary disease and lung function in the geothermal area of Mt. Amiata in Italy: The cross-sectional InVETTA study
Full text linkBackground: The geothermal power plants for electricity production currently active in Italy are all located in Mt. Amiata area in the Tuscany region. A cross-sectional survey was conducted in the framework of the regional project "InVETTA-Biomonitoring Survey and Epidemiological Evaluations for the Protection of Health in the Amiata Territories", using objective measures of lung function to investigate the role of hydrogen sulphide (H2S) in affecting the respiratory health of the population living in this area. Methods: 2018 adults aged 18-70 were enrolled during 2017-2019. Home and workplace addresses of participants were geocoded. Dispersion modelling was used to evaluate the spatial variability of exposure to H2S from the geothermal power plants' emissions. We estimated average long-term historical exposure to H2S and more recent exposure indicators. Chronic Obstructive Pulmonary Disease (COPD) was defined according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD). Multivariable logistic regressions were performed to investigate associations between outcome and exposure. Results: Our findings did not showed any evidence of an association between increasing H2S exposure and lung function impairments. Some risk reductions were observed: a -32.8% (p = 0.003) for FEV1<80% and a -51.7% (p = 0.001) risk decrease for FVC<80% were associated with interquartile increase (13.8 μg/m3) of H2S levels. Conclusion: Our study provides no evidence that chronic exposure to low levels of H2S is associated with decrements in pulmonary function, suggesting that ambient H2S exposure may benefit lung function
Variations on the Author
Full text link“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
Full text linkWe 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
Meningococcal C conjugate vaccine effectiveness before and during an outbreak of invasive meningococcal disease due to Neisseria meningitidis serogroup C/cc11, Tuscany, Italy
Full text linkIntroduction: In Tuscany, Italy, where a universal immunization program with monovalent meningococcal C conjugate vaccine (MCC) was introduced in 2005, an outbreak of invasive meningococcal disease (IMD) due to the hypervirulent strain of Neisseria meningitidis C/cc11 occurred in 2015–2016, leading to an immunization reactive campaign using either the tetravalent (ACWY) meningococcal conjugate or the MCC vaccine. During the outbreak, IMD serogroup C (MenC) cases were also reported among vaccinated individuals. This study aimed to characterize meningococcal C conjugate vaccines (MenC-vaccines) failures and to estimate their effectiveness since the introduction (2005–2016) and during the outbreak (2015–2016). Methods: MenC cases and related vaccine-failures were drawn from the National Surveillance System of Invasive Bacterial Disease (IBD) for the period 2006–2016. A retrospective cohort-study, including the Tuscany' population of the birth-cohorts 1994–2014, was carried out. Based on annual reports of vaccination, person-years of MenC-vaccines exposed and unexposed individuals were calculated by calendar-year, birth-cohort, and local health unit. Adjusted (by birth-cohort, local health unit, and calendar-year) risk-ratios (ARR) of MenC invasive disease for vaccinated vs unvaccinated were estimated by the Poisson model. Vaccine-effectiveness (VE) was estimated as: VE = 1-ARR. Results: In the period 2006–2016, 85 MenC-invasive disease cases were reported; 61 (71.8%) from 2015 to 2016. Twelve vaccine failures occurred, all of them during the outbreak. The time-interval from immunization to IMD onset was 20 days in one case, from 9 months to 3 years in six cases, and ≥7 years in five cases. VE was, 100% (95%CI not estimable, p = 0.03) before the outbreak (2006–2014) and 77% (95%CI 36–92, p < 0.01) during the outbreak; VE was 80% (95%CI 54–92, p < 0.01) during the overall period. Conclusions: In Tuscany, MenC-vaccine failures occurred exclusively during the 2015–2016 outbreak. Most of them occurred several years after vaccination. VE during the outbreak-period was rather high supporting an effective protection induced by MenC-vaccines
Injury Mortality in Tuscany, 1987-2001
No full textIntroduction. Injuries are a considerable public health problem throughout the world and account for deaths, disability and suffering. We know that injuries are a rather heterogeneous group of illnesses, with different aetiology and risk groups, which share one important thing, namely the fact that they can all be prevented. Given that access to information is the key to sound policy-making, this paper provides an overview of injury mortality in Tuscany over the past 15 years. Methods. Information on deaths from major external causes (Codes: E900-E999) from 1987 to 2001 was obtained from the Tuscan Mortality Register. Mortality indicators by all injuries and major categories (road traffic injuries, falls, suicide, etc.) were calculated and analyzed according to the triad of time, place and person. Results. In the fifteen-year period considered, 27,844 injury deaths were registered (16,606 males and 11,238 females). The standardized rates were higher in males (52.7/100,000) than in females (21.4/100,000). From 1987 to 2001, we observed that while the death rates decreased in both males (-18%) and females (-19%), the number of deaths increased among females (+ 5%) when the ageing of the population is taken into consideration. Southern areas showed a higher risk of mortality. Discussion. Major advancements in the control of injuries will rely on evidence-based preventive actions
Lung function in a cohort of 5-year-old children born very preterm
No full textObjective: We assessed lung function and respiratory health in an area-based prospective cohort of preschool children born very preterm. Design: Lung function was measured by interrupter respiratory resistance (Rint) and forced oscillation technique (FOT) (respiratory resistance (Rrs8), reactance (Xrs8), and area under the reactance curve (AX)) at a median age of 5.2 years in a cohort of 194 children born at 22-31 weeks of gestational age (GA) in Tuscany, Italy. Respiratory symptoms and hospitalizations were also assessed. Results: Mean (SD) lung function Z-scores were impaired in preterm children for Rint (0.72 (1.13)), Xrs8 (-0.28 (1.34)), and AX (0.29 (1.41)). However, only a relatively small proportion of children (14.5-17.4%) had values beyond the 95th centile or below the 5th. Children with bronchopulmonary dysplasia (BPD) (n = 24) had slightly but not significantly impaired lung function indices in comparison with those without BPD (n = 170). In a multivariable analysis, lower GA was associated with worse lung function indices. Fifty-five percent of children had a history of wheezing ever and 21% had been hospitalized in their lifetime because of lower respiratory infections; 31% had wheezing in the last 12 months and this was associated with increased Rrs8 (P = 0.04) and AX (P = 0.08), and with decreased Xrs8 (P = 0.04) Z-scores. Conclusions: Irrespectively of BPD preschool children born very preterm had impaired lung function indices, as measured by Rint and FOT, and a slightly higher burden of respiratory problems than the general population. GA seems to be crucial for lung development
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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