1,721,019 research outputs found
Geochemical characterization and rare earth elements anomalies in surface- and groundwaters of the Romagna area (Italy)
No full textHighly industrialized and urbanized areas can be affected by microcontamination due to the inefficiency of wastewater treatment plants to remove micropollutants from effluents, with the consequence of reversing them totally or only partially undegraded in the environment. Gd, one of the rare earth elements (REE) group, can be considered as a tracer of wastewaster effluents contamination. It is commonly used as contrast agent in magnetic resonance imaging and it can be detected in hospital and wastewater discharges. In this study, surface- and groundwater quality of the Romagna area was assessed, with a particular focus on REE content in water. The efficiency of two drinking water treatment plants in removing microcontamination was also evaluated comparing REE concentrations at the entrance and exit of the plants. Chemical analyses on a large set of trace elements, as well as major ion content, were performed to geochemically characterize surface- and groundwaters and to investigate possible relations with REEs. The study revealed water chemistry of both surface- and groundwaters mainly controlled by carbonates and clay minerals contribution. As regards REEs, Gd contamination was detected only in surface waters in the northern part of the study area; in the Lamone river, this contamination was accompanied by the detection of La anomalies, reflecting a contaminated environment. The two drinking water treatment plants showed that common water treatment techniques are often inefficient to remove microcontamination
Univariate data analysis and mapping
No full textInsgesamt waren an der Durchführung des Projektes weltweit über 60 internationale Organisationen und Institutionen beteiligt. In den Jahren 2008 und 2009 wurden in 33 europäischen Ländern auf 5 600 000 km² insgesamt 2108 Ackerproben (regelmäßig gepflügte Felder, 0-20 cm, Ap-Proben) und 2023 Grünlandproben (ungepflügt, 0-10 cm, Gr-Proben) entnommen. Damit liegt nun für die europäischen Landwirtschaftsböden ein qualitätsgesicherter geochemischer Datensatz mit einer Belegungsdichte von einer Probe pro 2500 km² vor, an dem in jeder Ackerund Grünlandprobe 52 Elemente im Königswasseraufschluss, 41 Elemente als Gesamtgehalte, 57 Elemente in der mobilen Metallionenfraktion (MMI®) sowie die Bleiisotopenverhältnisse, die MIR-Spektren, die Korngrößenverteilung, die pH-Werte (CaCl₂), TC und TOC, die effektiven Kationenaustauschkapazitäten und die Kd-Werte bestimmt wurden. Die vorliegenden Ergebnisse erlauben erstmals europaweit eine Evaluierung und Darstellung der Bioverfügbarkeit der Elementgehalte im kontinentalen Maßstab und ermöglichen damit eine reale Risikobewertung im Rahmen der REACH-Vorgaben.During 2008 and until early 2009, a total of 2108 samples of agricultural (ploughed land, 0-20 cm) and 2023 samples of grazing land (0-10 cm) soil were collected at a density of 1 site/2500 km2 each from 33 European countries, covering an area of 5,600,000 km2. All samples were analysed for 52 chemical elements after an aqua regia extraction, 41 elements by XRF (total), and soil properties, like CEC, TOC, pH (CaCl2), following tight external quality control procedures. In addition, the agricultural soil samples were analysed for 57 elements in a mobile metal ion (MMI®) extraction, Pb isotopes and magnetic susceptibility. The GEMAS project thus provides for the first time fully harmonised data for element concentrations and soil properties known to influence the bioavailability and toxicity of the elements at the continental (European) scale. The provided database is fully in compliance with the requirements of the European REACH Regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals)
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
Arsenic: Geochemical distribution and age-related health risk in Italy
Full text linkThis study is the first attempt to evaluate occurrence, distribution and potential health impacts of As at a national scale in Italy. In various environmental matrices, As geochemical distribution was investigated and carcinogenic and non-carcinogenic risks were assessed with respect to different exposure routes and age groups. Both deterministic and probabilistic methods were used to determine the health risks. Geochemical mapping at a sub-continental scale provided a useful tool to spatially represent As concentration and the critical areas posing a health threat to inhabitants. The results show that significant As concentrations in tap water and soil (up to 27.20 μg/l and 62.20 mg/kg, respectively) are mainly governed by geological features. In the central parts of Italy, where alkaline volcanic materials and consequently high levels of As occur, the residents are prone to health issues. Daily exposure to As in tap water is unparalleled playing an important role in the potential cancer and non-cancer risks. The Incremental Lifetime Cancer Risk for skin cancer and also lung and bladder cancer associated with tap water ingestion interestingly shows that (i) almost 80% of the computed values fall above the internationally accepted benchmark value of 1 × 10−5; (ii) majority of the data exceed the acceptable risk proposed by most jurisdictions, such as that of Italian law (1 × 10−6). Further, geographical variation of health risk highlights high carcinogenic and non-carcinogenic risk associated with water ingestion for those living in the northern Alps (including the city of Trento) and the central and southern Italy (including the capital Rome and the cities of Napoli and Catanzaro). According to the results, application of the probabilistic method which considers variability and uncertainty is preferred to the deterministic approach for risk assessment. The sensitivity analysis showed that As concentration in drinking water and exposure duration are the factors with the greatest impact on the outcome of risk assessment (for all age groups). The results of the current study may be a good starting point for authorities to urgently decide about the needed policy actions in order to prevent the adverse health effects and to reduce the human health risk due to As exposure
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
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