1,720,953 research outputs found
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
Identification of rotundone as an important contributor to the flavor of oak aged spirits
Get PDFThe practice of barrel aging of spirits has been used for centuries. It began as an alternative storage and transportation method, but aging in an oak cask is now exclusively used as a means to impart flavor to the spirits. Oak wood is the wood of choice for barrel making, not only for its physical characteristics that lend itself to manufacturing a barrel, but also for its unique chemical properties that impart key flavors to aged spirits. Oak aging of spirits develops flavor in a number of different ways, all which contribute to a wide range of odor descriptions, creating the complex flavor with which we are familiar. Extensive research has been performed on oak wood and oak aged spirits; however, the identity of the component(s) responsible for the “woody/incense” flavor attribute of age spirits was, prior to this investigation, unknown. Experiments were conducted in order to unambiguously identify a compound responsible for a “woody/incense” odor note in oak aged spirits. The target compound was isolated from oak wood chips followed by several purification steps, as well as the use of a custom built GC-MS/olfactometry system equipped with a heart-cutting system/internal CryoTrap which enabled the acquisition of an interpretable electron-impact mass spectrum (EI-MS) for the compound. The EI-MS revealed that the unknown target compound possessed a molecular weight of 218. A thorough investigation of naturally occurring organic compounds having a molecular weight of 218, along with deducing the nature of the functional groups on the molecule, indicated numerous compounds as possible candidates. Most of these compounds were found to occur naturally in a number of roots, spices, oils, and herbs, which were subsequently analyzed. Results of the analyses revealed that the compound was most likely the sesquiterpene ketone 5-isopropenyl-3,8-dimethyl-3,4,5,6,7,8-hexahydro-1(2H)-azulenone, or rotundone. This identification was confirmed by comparison of the compound’s EI-MS and GC retention indices against those of authentic rotundone obtained by chemical synthesis. The next question addressed was whether this compound is present in oak aged spirits. Accurate quantification of this trace level target compound was done by stable isotope dilution analysis (SIDA). The presence of rotundone in different aged spirits including bourbons, rye, scotch, whiskey, rum, and tequila was demonstrated. Trends in aging were established, showing that rotundone increases with aging time; however, its quantity may also be influenced by other factors as there was a clear brand to brand variation. Interestingly, rotundone was also found in un-aged (silver) tequila, which suggests that the compound may also be present in the agave plant. Results of quantification of all potent odorant in bourbons, aged 4, 8, and 12 years and calculation of their odor activity values (OAVs) demonstrated rotundone’s importance to the overall flavor of bourbon. From the quantification data some interesting trends were established that demonstrate some effects of barrel aging. OAVs are used as a gauge for potency and, generally, any compound with an OAV above 1, provides evidence of whether a compound is important. With an OAV of 42.8 to 56.6, rotundone lies well above this requirement and is among the top 10 odorants quantified in these samples. Thus, it is concluded that rotundone is an important contributor to the flavor of these aged spirits.Item withdrawn by Mark Zulauf ([email protected]) on 2014-04-22T20:22:41Z
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Group with Access UIUC Users [automated]
Release Date: 2016-05-30 12:09:03 UTC
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemItem marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Seth Robbins ([email protected]) on 2014-05-30T17:09:53Z
Item is restricted until 2016-05-30T17:09:03ZU of I Only Restriction Lifted for Item 49780 on 2016-09-22T20:59:24Z
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
Identification of key odorants in fresh-cut watermelon aroma and structure-odor relationships of cis,cis-3,6-nonadienal and ester analogs with cis,cis-3,6-nonadiene, cis-3-nonene and cis-6-nonene backbone structures
No full textThe scope of this study involved the identification of key odorants in fresh cut-watermelon, and the synthesis and evaluation of esters with potential watermelon-like aroma attributes. Aroma formation in fresh-cut watermelon is a dynamic enzymatic process, with the characteristic aroma components being formed immediately after cutting. The characteristic fresh-cut aroma is not long lasting due to further enzyme action that modifies the fresh-cut aroma components. The key to identifying the key components responsible for fresh-cut watermelon aroma was the application of a suitable volatile isolation strategy based on static headspace analysis (SHA). In this study, SHA was used to collect the headspace volatiles one minute after initial cutting of the fruit. This enabled a chemical “snap shot” of fresh-cut aroma to be taken. The most potent odorants in the headspace were determined by gas chromatography-olfactometry of decreasing headspace volumes (GCO-H) with confirmation achieved by application of a complimentary method based on GCO and aroma extract dilution analysis (AEDA) of fresh-cut watermelon aroma extracts prepared by solvent-assisted flavor evaporation (SAFE). Eight unsaturated nine-carbon aliphatic aldehydes and one six carbon unsaturated aldehyde were detected by GCO-H. These included cis-3-hexenal, cis,cis-3,6-nonadienal, cis-3-nonenal, cis-6-nonenal, trans-2-nonenal, cis-2-nonenal, trans,cis-2,6-nonadienal, trans,trans-2,4-nonadienal, and trans,trans,cis-2,4,6-nonatrienal. This finding is contrary to previous beliefs that alcohols are the main contributors to fresh-cut watermelon aroma. Most importantly, it was found that cis,cis-3,6-nonadienal was not only a potent odorant, but this compound alone possessed an aroma reminiscent of fresh-cut watermelon. Use of sensory evaluation, including ranking test, revealed that the aroma attributes of purified synthetic cis,cis-3,6-nonadienal closely matched those of fresh-cut watermelon. This “watermelon aldehyde” can be considered a potent odorants since its estimated odor detection threshold (in water) is very low (0.2 ppb). Unfortunately, cis,cis-3,6-nonadienal is a labile compound and is prone to both trans isomerization and oxidation of its aldehyde end group. For this reason, an attempt was made to create an ester with watermelon-like aroma attributes. Esters have been widely used in the food and beverage industries as flavoring agents because they are both stable and possess relatively low thresholds. To develop a watermelon-like ester, alcohol (formate, acetate, propionate, and butyrate) and carboxylic acid (methyl, ethyl, propyl, and butyl) esters with cis,cis-3,6-nonadiene backbones were synthesized. To achieve a more thorough understanding of the structure-odor relationship of these esters, the same types of alcohol and carboxylic acid esters were created with cis-3-nonene and cis-6-nonene backbones. The general structure/threshold trend was that threshold increased with increasing carbon number. In addition, threshold was also dependent on the number and position of the cis double bond. Descriptive sensory analysis was used to evaluate the effect of structure on the odor properties of the selected (low threshold) esters; however, no clear trend was found. Finally, further sensory analysis by ranking test was employed to determine, which, if any of these esters might be a suitable replacement for cis,cis-3,6-nonadienal for use as a watermelon flavoring. Although all esters had a “fruity” element to their aroma descriptions, none were significantly close in terms of their aroma attributes to cis,cis-3,6-nonadienal.Item withdrawn by Mark Zulauf ([email protected]) on 2010-07-22T18:05:39Z
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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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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