1,721,002 research outputs found
Lifestyle influence on trace element contents in human scalp hair of young residents in different urban contexts. Preliminary results.
No full textA causal relationship between earth material and human health, although not always proven, is highly plausible because many chemical elements in rocks and soils are directly inhaled by respiration or transmitted, via air, water and vegetation, into food chain and then to human body. It is well known that metals and metalloids may result essential to biochemical and physiological functions, but it is also well known that health problems may derive from either dietary deficiencies or excesses. Among the techniques employed to assess the exposure of living organisms to metals and metalloids present in the environment, the human biomonitoring has attracted the attention of investigators over the past decades. More specifically, the human biomonitoring is a method for assessing human exposure to chemicals by measuring the searched chemicals or their metabolites in human tissues or specimens, such as blood, plasma, serum, breast milk, urine, teeth and also hairs. However, some of these specimens may not always be the best indicators of element intake because of the homeostatic system of control in the human body. Human hairs seem to be particularly appropriate as they offer several advantages. Hair are stable and their composition does not change over short time period. Furthermore, sampling procedure is very easy, requires no specific professional skills, is painless and non-invasive. The present study deals with the trace elements content of hair samples from the scalp of 136 young students, between 11 and 14 years of age, of female and male gender, resident in the metropolitan area of Palermo (80 samples) and in a small rural town, Altavilla (56 samples), 20 km far from Palermo. The concentrations of 18 elements (Al, As, Ba, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sb, Se, Sr, U, V, Zn) in hair were determined by ICP-MS. In order to eliminate external contamination, each hair sample was firstly properly washed. The obtained results were in line with the ranges of values published in other studies. The most abundant elements resulted Zn, Cu, Al, Sr, Ba, Pb in Palermo as well as in Altavilla, although with different abundance orders. All the remaining analyzed elements were below 1 ppm. Zn is known to be an essential element recognized in more than 300 enzymes depending on this element for catalytic, structural, and regulatory functions. Cu is considered an indispensable catalytic cofactor in redox chemistry for proteins. Al and Sr are typical geogenic elements; their different abundances in the Palermo and Altavilla samples are related to the different lithological site, carbonate rocks in Palermo and calcarenites-clays at Altavilla. Sr is also strictly related to calcium content in bones. The highest levels of most elements were found in Altavilla samples: this may indicate a possible different exposure due to different lifestyles, as evidenced by Al and Pb. In fact, children living at Altavilla spend more time outdoors than those living in Palermo. The higher Ba concentration in children from Altavilla may be also related to the Ba content of local drinkable water. Significant gender-related differences were found for certain elements. This was the case of Sr and Zn, more abundant in female subjects, and Cr, Li, Pb, Sb and U which were more abundant in males. When the elements are subdivided in essential and not essential, and their ratios with respect to aluminum are compared with those in air particulate matter and road dust, it appears evident that some elements typical of anthropogenic sources (Cd, Pb e Sb) are taken by PM10-2.5, PM2.5 and the finest fractions of road dust. Data concerning subjects exposed and not exposed to passive smoke are also reported. Further, it has been examined the relationship between exposure to passive smoke and concentration of nicotine (and its metabolite cotinine) in hairs. A first result of this work is that the reported data and concentration ranges can be used as guidelines for to evaluate environmental or occupational exposure to these elements
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
Determinants of Allergic Sensitization, Asthma and Lung Function: Results from a Cross-Sectional Study in Italian Schoolchildren
Full text linkPrenatal smoking exposure and early-life respiratory infections are major determinants of asthma during childhood. We investigate the factors influencing allergic sensitization (AS), asthma, and lung function in children and the balance between individual and environmental characteristics at different life stages. 1714 children aged 7-16 years and living in southern Italy were investigated using a parental questionnaire, skin prick tests, and spirometry. We found 41.0% AS prevalence: among children without parental history of asthma, male sex, maternal smoking during pregnancy (MatSmoke), and acute respiratory diseases in the first two years of life (ARD2Y) were significant risk factors for AS. MatSmoke was associated (OR = 1.79) with ARD2Y, and this association was influenced by sex. ARD2Y was, in turn, a significant risk factor (OR = 8.53) for childhood current asthma, along with AS (OR up to 3.03) and rhinoconjuctivitis (OR = 3.59). Forced mid-expiratory flow (FEF25-75%) was negatively affected by ARD2Y, with a sex-related effect. Thus, males exposed to MatSmoke had significantly lower FEF25-75% than unexposed males. Despite the difficulty of discriminating among the complex interactions underlying the development of allergic respiratory diseases, ARD2Y appears to strongly influence both asthma and lung function during childhood. In turn, ARD2Y is influenced by prenatal exposure to tobacco smoke with a sex-dependent effect
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
Correction: Circadian rhythm of COPD symptoms in clinically based phenotypes. Results from the STORICO Italian observational study (BMC Pulmonary Medicine (2019) 19 (171) DOI: 10.1186/s12890-019-0935-2)
No full textFollowing publication of the original article [1], the authors flagged that the article had been provided with the names of the authors (not including the STORICO study group) in the wrong order: the 'Given Names' and Family Names' were erroneously swapped around. Please see this table for the correct order of the names: (Table Presented) This error has now been corrected in the original article and the corrected author list is detailed in this article
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
Association of Blattella germanica sensitization with atopic diseases in pediatric allergic patients
Full text linkThe extent to which the sensitization to the German cockroach Blattella germanica (BG) affects onset/presence of rhinoconjunctivitis (RC) in children is unknown
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
- …
