1,723,012 research outputs found
[Pickands Mather & Co., Engine Drawing Card, Sketch No. 7937]
No full textThis engine drawing card was created for Pickands Mather & Company, Class 6-40 D. Section J-6 D. Sketch 7937. Copy Spec. C-9831
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
Synchronous Akinete Germination and Heterocyst Differentiation in Anabaena PCC 7937 and Nostoc PCC 6720
No full textIsolates of the filamentous cyanobacteria Anabaena PCC 7937 and Nostoc PCC 6720 were selected in which the germling extruded from the akinete coat at the single cell stage and in which heterocyst differentiation occurred at the two or three cell stage after germination in the absence of combined nitrogen. The process of heterocyst differentiation of these germinating akinetes was synchronous and highly reproducible, and it resulted in transient yields of mature heterocysts exceeding 35% of the total cell population
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
Validatie van microbiologische methoden; Telling van Clostridium perfringens volgens ISO 7937 (tweede editie, 1997)
No full textAls onderdeel van een Europees project werd de methode voor de telling van Clostridium perfringens in voedingsmiddelen en diervoeders, zoals beschreven in ISO 7937 (1997) gevalideerd. Een ringonderzoek werd georganiseerd om de precisie, zijnde de herhaalbaarheid (r) en de reproduceerbaarheid (R), van deze methode te bepalen. Zeventien laboratoria in 13 Europese landen analyseerden kaas, vlees, gedroogd diervoeder en een referentiemateriaal volgens een standaard protocol. Alle monsters waren kunstmatig besmet om het gewenste besmettingsniveau (blanco, laag, midden en hoog) en homogeniteit te verkrijgen. De studie bevatte twee technieken voor de bevestiging van vermoedelijk Clostridium perfringens, zodat mogelijke verschillen in prestatie gedetecteerd konden worden: 1) lactose-sulfiet medium (ISO 7937) en 2) lactose-gelatine medium en beweeglijkheid-nitraat medium (facultatief in EN 13401). De prestatiekenmerken werden berekend volgens zowel ISO 5725 (1994) als volgens prEN ISO 16140 (2000). De herhaarbaarheid (r) en reproduceerbaarheid (R) werden voor elk monster type, concentratieniveau en bevestigingsmethode afzonderlijk berekend. De precisie varieerde per monstertype. De analyse van de RMs leverde de beste prestatiekenmerken opThe method for the enumeration of Clostridium perfringens in foods and animal feeding stuffs, as described in ISO 7937 (1997), was validated in the context of a European project. A collaborative study was organised with the aim of attaining precision, in terms of repeatability (r) and reproducibility (R), of this method. Seventeen laboratories in 13 European countries examined cheese, meat, dried animal feed and a reference material according to a standardised protocol. All samples were artificially contaminated to achieve the desired inoculation levels (blank, low, medium, and high) and homogeneity. Two techniques using 1) lactose sulfite medium (ISO 7937) and 2) lactose-gelatine medium and motility-nitrate medium (optional method in EN 13401), were included in this study for confirmation of presumptive C. perfringens. This enabled detection of possible differences in the performance of the two confirmation methods. The precision characteristics were calculated using both ISO 5725 (1994) and pr EN ISO 16140 (2000). Repeatability (r) and reproducibility (R) were calculated for each sample type, inoculation level and confirmation method separately. The precision depended on the type of sample analysed. The best performance was found when analysing the RMs.European CommissionBrusse
- …
