1,720,965 research outputs found
Chemical and isotopic profiles from snow pits and shallow firn cores on Campbell Glacier, northern Victoria Land, Antarctica
No full textTrace elements in winter snow of the Dolomites (Italy): a statistical study of natural and anthropogenic contributions.
No full textKnowledge of the occurrence of trace elements deposited in fresh alpine snow is very limited. Although current sources of major ionic inorganic species have been well established, this is not the case for many trace elements. This manuscript attempts to reconstruct the origin of Ag, Ba, Bi, Cd, Co, Cr, Cu, Fe, Mo, Mn, Pb, So, Ti, U, V and Zn in winter surface snow, extensively collected in the Dolomites region (Eastern Alps, Italy). Sampling of surface snow was conducted weekly during the winter 1998 at 21 sites at altitudes ranging from similar to 1000 to similar to 3000 m. This led to a remarkable dataset of trace element concentrations in Surface snow from low latitudes. Here we show a preliminary statistical investigation conducted on the 366 samples collected. It was found that V, Sb, Zn, Cd, Mo and Pb have a predominantly anthropogenic origin, linked to the road traffic in the alpine valleys and the nearby heavily industrialised area of the Po Valley. In addition, the occasionally strong Fe and Cr input may reflect the mechanical abrasion of ferrous components of the vehicles. However, much of the Fe along with Mn, U and Ti originates primarily from the geological background of the Dolomites. A marine contribution was found to be negligible for all the trace elements. The origin of other trace elements is less clear: Ag can be possibly attributed to a predominantly anthropogenic origin while Cr, Co, Cu and Ba are usually from crustal rocks but different than the Dolomites. Published by Elsevier Ltd
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
Chemical profiles from snow pits and shallow firn cores and snow accumulation on Campbell Glacier (northern Victoria Land, Antarctica)
No full textThe chemical composition of snow and firn samples from the Campbell Glacier (Northern Victoria Land) was studied to evaluate the accumulation rate of snow and to investigate the chemical contribution from some different emission sources (marine biogenic activity, sea and crustal). Snow and firn were collected from snow pits and by coring at three sites (74°41'S-164°30'E; 74°15'S-164°04'E and 73 45 S-163°20'E), located respectively at 50 m (on the floating glacier tongue), 800 m and 1560 m a.s.l., during the 1994-95 Italian Antarctic Expedition. Analyses of Na+, K+, Mg++, Ca++, CH3SO3- (Msa), Cl-, NO3-, SO4(=) were performed by ion chromatography (Dionex 2020i). The separations were obtained with ion-exchange columns Dionex AS5 (NaOH 5 10-1 N and NaOH 3 10-2 N eluents) and Dionex CS12 (methane sulfonic acid 20 mM eluent) for anions and cations respectively. H2O2 was analyzed by an electrochemical detector (Antec mod. 'Decade'). Samples from the Campbell Glacier Tongue are characterized by a high level of sea salt and in the upper part of the firn layer a high concentration of nss SO4(=) is present. The concentration of sea salt decreases with increasing distance from the coast and with altitude. The differences in the chemical composition of firn at the sites at 800 m and 1560 m altitude could be explained by coupling fractionation of chemical species and air masses of different origin. Msa, H2O2, nss SO4(=), NO3- and nss Ca++ profiles show fairly good seasonal cycles. 10-11 and 14-17 years have been identified at the sites of 800 m and 1560 m altitude respectively. The accumulation rate ranges between 150-170 kg m-2 y-1 and 150-180 kg m-2 y-1 at the first and the second of these two sites
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
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