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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
[Home-built electrospray ionisation source for a quadrupole mass-spectrometer.]
No full textThis report describes the manufacturing, the working and results of preliminary applications of a home-built electrospray ionisation source. The source was constructed for a quadrupole mass-spectrometer (MS) (Finnigan 4000). The elements of the source and interface are: a micro needle at high potential to the capillary, a capillary for transport of the ions and a sampling orifice (skimmer) to the mass analyser and detector. That interface enables the transport of ions from atmospheric pressure to the required high vacuum in the mass analyser as well as an appropriate focussing of ions corresponding. The design concerns the physical dimensions of the different parts and the electrical potentials. The results show that the electrospray process, the transport and the focussing operate satisfactorely. The highest sensitivity was measured for Gramicidin S (polypeptide, MW 1141 Dalton) of about 10 femtomol. For substances with a lower molecular weight the sensitivity was much lower and ranged from about 100 fmol for the polysaccharide streptomycin (MW 581 Da) to 50 pmol for polar low MW herbicides glyfosate and glufosinate. It seems useful to construct an extra focussing device between the skinner and the analyser to enhance the transmission efficiency for the low molecular weight species (<400 Da)
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
Groot vluchtigheidstraject bepaling van polycyclische aromatische koolwaterstoffen (PAK�s) in de buitenlucht m.b.v. gaschromatografie - isotoopverdunning massa spectrometrie
No full textEen methode is ontwikkeld voor de meting van poly aromatische koolwaterstoffen (PAK) in de buitenlucht m.b.v. gaschromatografie - isotoopverdunning massa spectrometrie. De methode was ontworpen voor de meting van de grootst mogelijke vluchtigheidstraject binnen de groep inclusief de meestvoorkomende en vluchtige naftalenen. Het monstervolume bedroeg circa 500 m3 bij een bemonsteringssnelheid van ca. 18 m3/h. Het monstername apparaat bevatte drie sorptie trappen voor de simultane bemonstering van resp. de deeltjes gebonden fractie, de weinig vluchtige en de vluchtige PAK�s. De recoverie van de methode bedroeg gemiddeld ca. 90 %. De detectiegrens was circa 5 pg/m3 voor de niet-vluchtig en deeltjes gebonden fractie. Resultaten van toepassing van de methode in een woongebied (Bilthoven) toonden een vrij stabiel profiel van voorkomen van de belangrijkste PAK congeneren in achtergrondlucht. Vergelijking van specifieke verhoudingen van bepaalde PAK congeneren met literatuur gegevens duidde op een belangrijke bijdrage van verkeer aan PAK�s in lucht.A method was developed for the measurement for polycyclic aromatic hydrocarbons in ambient air by gas chromatography isotope dilution mass spectrometry. The method was designed to measure the largest possible volatility range of PAHs including the abundant naphthalenes. Samples volumes were approx. 500 m3 in size at a sampling rate of approx. 18 m3/h. The sampler contained three sorption stages for the simultaneous capturing of particle bound and low and high volatile gaseous PAHs, respectively. Recoveries of sampling spikes were on average 90 %. The detection limit was approx. 5 pg/m3 for the high boiling range PAHs. Results obtained showed a quite steady profile for most PAHs in background air in the Netherlands. Comparison of abundance ratios with data in the literature indicate that traffic exhausts were the major source for the PAHs in the area.RIV
WHO Gecoordineerd interlaboratorium onderzoek over de analyse van dioxines and PCB's in moedermelk en bloed
No full textAbstract niet beschikbaarThis report describes the results of a WHO-coordinated interlaboratory comparison study on the analysis of dioxins and PCBs in mother's milk and human blood. The study is biannually organised by the WHO, Regional Office for Europe (Copenhagen) and is aiming at the identification of laboratories capable of the analysis of dioxins and related compounds at a good, internationally accepted standard. In the present study, nineteen laboratories from Europe and North- America have participated for dioxins in mother's milk, sixteen for dioxins in blood and ten and sic for the analysis of PCBs in mother's milk and human blood, respectively. The study consisted of the analysis of three different pools of milk and blood, two of which contained added PCDD/Fs. One of the pools was sent after the results of two previous pools have been reported (test for reproducability). Results were evaluated on the basis of statistical analysis in terms of repeatability, reproducibility and accuracy. In general, coefficients of varation (CV) were better for analysis in mother's milk than for the lower levels in blood. Limits for the qualification of methods were average coefficients of variation of < 20% for analysis of PCBs in milk and blood, <30% for dioxins in milk and <40% for dioxins in blood. All our four methods have been qualified. In the final ranking of laboratories, RIVM-LOC methods scored first positions for PCBs and dioxins in milk and for PCBs in blood and a third position for the analysis of dioxins in blood. The average CVs were 12.4, 3.3, 8.7 and 11,3% for analysis for PCBs and dioxins in milk and blood, respectively.HIMHHIG
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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