1,721,029 research outputs found
Biomass fuel and coronary heart disease among women in Pakistan
No full textI investigated the risk of coronary heart disease (CHD) from indoor air pollution caused by use of biomass fuel for cooking. Following a systematic review of the relevant scientific literature, I conducted three linked studies among women in a rural region of Sindh, Pakistan.The first was an investigation of levels of pollutants in kitchens and their determinants. 24-hour average concentrations of fine particulate matter (PM2.5) and carbon monoxide (CO) were measured in samples of households that used biomass or natural gas for cooking, and information was collected about other factors that might influence pollution levels. Associations with pollution were explored by regression modelling.Secondly, a cross-sectional survey of cardiovascular morbidity was conducted in a sample of women aged 40 years or older who had used biomass fuel for cooking for at least the past year (n = 436), and a similar number of women (n=414) who had used natural gas for cooking for at least the past year. CHD was indicated by history of angina (Rose questionnaire), previous history of heart attack, and changes of CHD on electrocardiogram (ECG). Hypertension was assessed as a further outcome. Potential risk factors were ascertained by questionnaire and anthropometry. Associations between CHD outcomes and risk factors were assessed by logistic regression, adjusting for potential confounders.The third study used a case-control design to determine the association of acute coronary syndrome (ACS) with use of biomass fuel. Women from a defined geographical area who were admitted to two public tertiary care hospitals in southern Sindh with ACS (n = 364) were identified prospectively, and compared with controls (n=727), matched for sex and age, who were admitted to the same hospitals for reasons other than ACS. Information about exposure to potential risk factors, including use of biomass fuel for cooking was ascertained through a questionnaire. Associations with risk factors were assessed by conditional logistic regression.The first study found high average concentrations of CO and particularly PM2.5 in the kitchens of biomass-users. Ventilated kitchens tended to have lower levels of the pollutants, and houses with smokers somewhat higher concentrations. However, stove chimneys had no discernible impact on levels of PM2.5. In my cross-sectional survey, I found no association of hypertension or the three measures of CHD – angina, previous history of heart attack and definite or probable CHD on ECG - with current use of biomass for cooking. This may have been because of inaccuracies in the outcome measures, or because most users of natural gas had previously used biomass. In contrast, the case-control study found a clearly elevated risk of ACS among women who had ever used biomass for cooking, although not particularly with more recent use.Overall, my findings add to the weight of evidence for an importantly increased risk of CHD from use of biomass for cooking, and are a further encouragement to initiatives aimed at reducing exposures to the indoor air pollution that it produces. However, they suggest that the full benefits from better design of stoves or switching to other fuels may not accrue until many years after the changes are introduced. Further studies are needed to clarify the relationship of cardiovascular morbidity to use of biomass fuel These could perhaps be embedded in established cohort studies of cardiovascular disease and national surveys
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Radio frequency interference on nearby radio astronomical lines: relationship between wind speed and radio signal strength measured at East coast of Peninsular Malaysia
No full textThe East coast of Peninsular Malaysia receives a strong wind speed, heavy rain and high humidity during the Northeast monsoon. The Malaysian Meteorological Department claims that the wind speed during the Northeast season could reach 55.56 km/h or more. This strong wind speed and heavy rain could contribute to the attenuation of radio signals. This paper investigated the relationship between wind speed (km/h) and radio signal strength, RSS (dBm). The statistical correlation was employed to identify the correlation value and strength between them. The wind speed and RSS were collected during wet and dry seasons at Kusza Observatory, while the Spectrum analyser was used for measuring RSS (dBm) and the weather station for wind speed (km/h). The result showed that the wet season has strong and significant correlation compared to the dry season. Frequencies of 382.5 MHz, 945 MHz and 2160 MHz with correlation values of r = -0.583-0.631 and -0:514, respectively, showed strong, negative and significant correlations with wind speed in the wet season. As for the dry season, only a frequency of 382.5 MHz showed a strong, positive and significant correlation with r = 0.555, while small and medium for others. This finding is useful to a radio astronomer to help determine the best period for radio astronomy observation with the lowest interference considering the weather in the East Coast of Peninsular Malaysia. Besides, this finding benefits a spectrum of users involved in mobile telecommunication, wireless internet, radio TV transmission and satellite broadcasting
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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