1,721,041 research outputs found
Urinary trans, trans-muconic acid and S-phenylmercapturic acid are indicative of exposure to urban benzene pollution during childhood
No full textThe aims of the study were to evaluate the feasibility of urinary trans, trans-muconic acid (u-t,t-MA) and urinary S-phenylmercapturic acid (u-SPMA) as markers of exposure to urban benzene pollution for biomonitoring studies performed on children and to investigate the impact that creatinine correction may have on the classification of children exposure status. U-t,t-MA u-SPMA u-cotinine, and u-creatinine levels were measured in urine samples of 396 Italian children (5-11 years) living in three areas with different degrees of urbanisation (very, fairly and non-urban). The median u-SPMA levels significantly increased with increased urbanisation: non-urban (0.19 mu g/L; 0.22 mu g/g creatinine) < fairly urban (0.28 mu g/L: 0.28 mu g/g creatinine) < very urban group (0.92 mu g/L; 0.90 mu g/g creatinine). Differences in the levels of u-t,t-MA excretion related to the degree of urbanisation were revealed only by multivariate analyses. Neither u-SPMA nor u-t,t-MA levels were influenced by environmental tobacco smoke (ETS) exposure. Athletic activity during the sampling day was negatively associated with u-SPMA in the model built with u-SPMA adjusted for creatinine, but not in the model where unadjusted u-SPMA was used. This finding demonstrates that u-creatinine correction may alter the results when an independent variable is unrelated to the chemical concentration itself but is related to the u-creatinine levels. These results suggest that both u-SPMA and u-t,t-MA are indicative for assessing environmental benzene exposure in children (exposed and unexposed to ETS) when urine sample is collected at the end of the day. However, u-SPMA is more reliable because u-t,t-MA, also a metabolite of sorbic acid, is less specific for exposure to low levels of benzene. To avoid the possible confounding effect of creatinine correction, it is better to use u-creatinine as additional independent variable in multiple linear regression analyses for evaluating the independent role of the covariates on the variability of u-t,t-MA and u-SPMA levels. (c) 2012 Elsevier B.V. All rights reserved
How home-smoking habits affect children: A cross-sectional study using urinary cotinine measurement in Italy
No full textTo assess the impact of different home-smoking rules and smoking habits of cohabitant on environmental tobacco smoke (ETS) exposure of children. Information about 396 Italian children (5-11 years old) and cohabitants' smoking habits was collected by a questionnaire. Exposure assessment was performed by determination of urinary cotinine (u-cotinine). Median u-cotinine concentrations in children significantly increased in a similar fashion as theoretical ETS exposure increase: cohabitants do not smoke (1.79 mu g/g creatinine), cohabitant(s) smoker(s) never smoke at home (2.84), smoke at home only when children are out (3.90), and smoke at home even if children are in (6.02). Median u-cotinine levels of exposed children were associated to the strength of cohabitant's smoking behaviours when smoker(s) consume daily a high number of cigarettes (a parts per thousand yen 20) respect to light consumption (1-9) (4.52 and 3.24 mu g/g creatinine). The magnitude of ETS exposure in children is correlated with smoking habits and home-smoking precautions adopted by their cohabitants. Educational interventions on parents are essential to increase their awareness about ETS exposure and to teach correct behaviours to protect health of kids, especially in household environment
Biomarkers of oxidative stress to nucleic acids: Background levels and effects of body mass index and life-style factors in an urban paediatric population
No full textThe aims of the present study were to establish the background levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), 8-oxo-7,8-dihydroguanosine (8-oxoGuo), 8-oxo-7,8-dihydroguanine (8-oxoGua) among a group of healthy Italian children, and to evaluate the contribution of some potential interfering/confounding factors to the urinary (u) levels of these biomarkers of oxidised guanine derivatives. The levels of 8-oxodGuo, 8-oxoGuo, 8-oxoGua, and u-cotinine in urine samples from 159 healthy children (5-11years) recruited in a cross-sectional study were measured via liquid chromatography-tandem mass spectrometry. Data regarding the anthropometric and life-style characteristics of the participants were obtained from questionnaires. The 5th-95th percentiles of the levels of 8-oxodGuo, 8-oxoGuo, and 8-oxoGua for all children were 2.4-13.9, 3.8-19.9 and 5.4-79.5μg/L and 2.9-12.6, 4.8-15.2, and 5.1-93.4μg/g creatinine, respectively. Significant correlations were found between the level of 8-oxoGuo and that of 8-oxoGua and 8-oxodGuo but not between the level of 8-oxoGua and that of 8-oxodGuo in all children and in both the male and female subgroups. Multiple linear regression analyses revealed the independent effect of the investigated variables on 8-oxodGuo, 8-oxoGuo, and 8-oxoGua. u-Creatinine was the most significant predictor of the urinary excretion of both 8-oxoGuo and 8-oxodGuo, age displayed a significant positive independent effect on the level of 8-oxoGuo, whereas the weight status according to the BMI was negatively associated with the level of 8-oxodGuo. None of the chosen independent variables influenced the levels of 8-oxoGua
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
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
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
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
- …
