1,720,955 research outputs found
Characterisation of four popular Polish hop cultivars
No full textPolish cultivars of hop (Humulus lupulus L.) are well known as aroma and bitter raw material in the brewing industry. To characterise four popular Polish hop cultivars, Lubelski (Lublin), Marynka, Sybilla and Iunga (also known as Junga), the essential oil profiles were determined by gas chromatography/flame ionisation detector (GC-FID) and gas chromatography/chemical ionisation mass spectrometry (GC-CIMS) and the alpha/beta acids amounts by high-performance liquid chromatography/diode array detector (HPLC-DAD) analysis. In addition, the multivariate statistical analysis of the volatile profiles was performed. The results obtained evidenced qualitative and quantitative differences between the four cultivars studied and the foreign hops described in the literature. Lubelski and Iunga showed the typical chemical profile of the fine-aroma and high-alpha cultivars, respectively. In Marynka and Sybilla, the average amounts of alpha acids were similar to the bitter hops, but with a volatile profile characteristics of the fine-aroma and aroma cultivars respectively. �� 2013 Institute of Food Science and Technology
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
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
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
Aroma profile and bitter acid characterization of hop cones (Humulus lupulus L.) of five healthy and infected Polish cultivars
No full textThe characteristic hoppy aroma is directly correlated with the chemical composition of its volatile profile and essential oil. The aim of this work was to analyse the essential oils and volatile fractions of five popular Polish hop cultivars (Sybilla, Lubelski, Pulawski, Magnat and Marynka), healthy and infected by viruses and viroids by SPME and GC–MS. Hop fraction of hard resins and alpha- and beta acids were determined according to the official analytical method (modified Wöllmer method EBC 7.7 and HPLC method EBC 7.5, respectively). Hop Mosaic Virus (HpMV), Apple Mosaic Virus (ApMV), Hop Latent Viroid (HLVd) are commonly found in plants of all hop cultivars commercially produced in Poland. Monoterpenes hydrocarbons showed higher percentages in the aroma profile of infected cones (82.5%–94.3%) than in the healthy ones (81.1%–91.4%) and increased from the healthy to the infected plants, except for ‘Sybilla’ that had an opposite trend (from 90.1% in healthy to 77.9% in infected hop). Hydrogenated sesquiterpenes were the second main class of aroma constituents with major amount in healthy cones with the exception for ‘Sybilla’. Myrcene was always the most abundant chemical constituent in all the infected cultivars, except for ‘Sybilla’ (from 86.3% in infected to 74.6% in healthy plants), followed by α-humulene in four of the five cultivars except for ‘Marynka’ where (E)-β-farnesene showed higher amount. The EO yields related to the five healthy cultivars showed variations between 0.2% in ‘Lubelski’ up to 1.1% in ‘Marynka’ very similar to those observed in the five infected cultivars. Monoterpenes predominated over sesquiterpenes in healthy and infected ‘Sybilla’ and ‘Marynka’ EOs, while in healthy and infected ‘Lubelski’ and ‘Magnat’ prevailed an opposite trend. ‘Magnat’ is the only one cultivar that showed different amount of the two main classes of constituents between the healthy and infected plants (sesquiterpenes 64.6% in healthy cones and 50.5% of monoterpenes in the infected ones). Myrcene was the main constituent in all the infected EO samples (29.9%–67%), while α-humulene predominated only in three healthy cultivars (‘Lubelski’ ‘Pulawski’ and ‘Magnat’ with 34.2, 36.8, 31.0%, respectively). The content of bitter substances (α and β-acids as well as hard and soft resins) varied in healthy and infected hop plants and this behaviour was strongly dependent on the selected cultivars but differences between healthy and infected plants were not statistically significant. In conclusion virus/viroid infection seems not to interfere in a substantial way with the normal hop secondary metabolite biosynthesis, but only in the biomass yields
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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