1,720,954 research outputs found
GEOLOGICAL AND ANTHROPOGENIC FACTORS INFLUENCING STREAM WATER CHEMISTRY IN NORTHERN VIRGINIA
No full textStream water chemistry depends on natural geological and anthropogenic factors in watersheds. Major anion concentrations were evaluated seasonally in 20 Northern Virginia Streams to determine the degree of changes in water chemistry by comparing anion concentrations with watershed size, land use, soil mineralogy, soil pore water, upstream water, porosity, and population density, this study investigates how roadway salt application affects high chloride concentrations in Northern Virginia urban streams. The findings will help us understand the geochemical process of salt application in the US during the winter. This study also analyzed the concentration of chloride and sulfate anions in soil pore water and surface water, as well as the relationships between these anions in five watersheds in Northern Virginia. This study, in addition, analyzed chloride and sulfate anions in soil pore water and surface water and the concentration of chloride and sulfate relationships between soil pore water and surface water in five watersheds in Northern Virginia. The study discovered chloride and sulfate in twenty watersheds, with chloride detected at higher volumes in watersheds like Difficult Run, Lake Burke, and Marumsco Creek. The study detected sulfates at a negligible concentration, which influenced water bodies and aquatic life. The result also unveils variations in chloride concentrations in seven watersheds from 2019 to 2020. Summer and fall had low-to-medium levels in Difficult Run and South Four Mile Run. However, there was a significant increase in Winter due to salt application on roads in Northern Virginia, as well as snow and ice deicing. Lastly, the study also establishes chloride and sulfate anions in urban watersheds. The study reveals that Chloride ions are more concentrated than sulfate ions in all five selected watersheds, with Backlick Run and Difficult Run having significant chloride concentrations. Accotink Creek, Aquia Creek, and Bull Run have lower concentrations, while Blacklick Run and Difficult Run have similar concentrations
Synthesis of some trifluoromethylated indolones
No full textThe indole core is a ubiquitous substructure in many natural products and biologically active compounds. Due to their biological activity, indole-based compounds attract special attention as building block for the development of therapeutic agents. 5-Trifluoromethyl-1,3-cyclohexandione previously developed in our lab as a multi-faceted trifluoromethyl building block, was reacted with a range of acid chlorides to give different tricarbonyl compounds in a one-pot multi-component reaction. In this report, we describe the synthesis of novel fluorinated 6, 7-dihydro-1H-indol-4 (5H)-ones as potential antitumor agents. Starting with the above tricarbonyl compound, we have been able to synthesize several of these derivatives. In addition, the tricarbonyl compounds are further cyclized with amines and aniline in the presence of acetic acid to produce trifluoromethylated Indolones in moderate to good yields. The hypotheses are the trifluoromethylated Indolones will display anticancer activity in several human cell lines. Their antitumor activity will be investigated using established procedures. 2-(2-(4-chlorophenyl)-2-oxoethyl)-5-(trifluoromethyl) cyclohexane-1, 3-dione was prepared from 5-trifluoromethyl-1, 3-cylohexanedione and 2-bromo-4-chloroacetophenone in the presence of dry chloroform. 11 novel fluorinated 6, 7-dihydro-1H-indol-4(5H) were prepared by treatment with fluorinated tricarbonyl compounds and substituted anilines/amines in acetic acid. 8 bis-spiro piperidines were prepared via a three-component condensation of anilines and one equivalent of 5-trifluoromethyl-1, 3-cyclohexanedione in the presence of excess formaldehyde. In addition, 6 6,6-dimethyl-1-phenyl-2-(trifluoromethyl)-6,7-dihydro-1H-inden-4(5H) one was prepared by reacting diketones with anilines in the presence of acetic acid and was refluxed for 24h at 60°C. All of the above compounds were purified by either column chromatography or by recrystallizion, and was further characterized by infrared spectroscopy (IR), Nuclear Magnetic Resonance spectroscopy (NMR), gas chromatography mass spectroscopy (GC-MS) and Liquid chromatography mass spectroscopy LC-MS. In the future this research will focus on determining the mechanism by which these novel fluorinated compounds inhibit tumor growth
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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