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Weathering properties of wood-plastic composites based on heat-treated wood and polypropylene
No full textSynthesis of Cyclopentenone Isoprostanes and Highly Functionalized Cyclopentanes
Get PDFCyclopentane ring itself or as an element of bicyclic or polycyclic systems is not only ubiquitous in nature but also an increasingly recognized structural motif for biomedical research and drug discovery. In this context, the first part of the thesis describes our efforts towards synthetic analogs of a natural epoxy cyclopentenone isoprostane known to possess anti-inflammatory bioactivity. Employing reported strategies seven novel cyclopentenone isoprostanes were provided to our collaborators to examine their bioactivity. Additionally, preliminary studies demonstrated that the analog bearing an azide functionality could be labeled with an alkyne-containing cyanine (Cy5) and thus could serve as a valuable tool to further study the signaling pathway of related isoprostanes.
While numerous methodologies have been developed for the synthesis of this structural entity, the employment of known strategies to access relevant structural analogs can still be tedious and challenging. Acknowledging that, the second part of the thesis covers our investigations towards the use of vinylboron derivatives in radical-mediated [3 + 2] annulation reactions. The development of an efficient route giving access to 1,1-diborylethene in gram scale allowed us to extend the scope of this reaction allowing the synthesis of substituted cyclopentanes flanked with two boronic ester moieties. The established processes are operationally simple, convergent, atom economical, and mild. Thus, the synthesis of cyclopentanes presenting sensitive functional groups is enabled.
Additionally, the utility of the synthesized cyclopentane platforms was demonstrated by taking advantage of the presence of either the iodine atom, the boron atom(s), or both functionalities. These functionalization products include intriguing and applicable bicyclo[3.1.0]hexanes decorated with a boronic ester moiety, allylic gem-diboronates, and homoallyiodides among others, and are all easily accessible in one or two steps
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
Life cycle inventory for currently harvested birch roundwood
No full textThe knowledge of the environmental performance of different products and services is vital in the modern world because of the climate change and other environmental problems that we are facing. Life cycle assessment is a valuable tool that allows to determine the environmental performance and compare products and services with the same function. There is no doubt that the importance of forests is crucial in the environmental protection, despite that raw wood products (roundwood, pulpwood and fuelwood) are not carbon neutral as previously thought because of the human activities during forest management processes. Apart from climate change, production of raw wood products also contribute to other environmental impact categories: acidification, eutrophication, photochemical oxidant formation and abiotic resource depletion. Previous studies have shown that the life cycle inventory (LCI) data for raw wood products should be collected from the site-specific not from more generic sources because of the significant differences in several geography and technology related factors. However, less discussed are time-related factors, which should also be acknowledged especially because of the long growing time of trees. The main objective of the present study was to determine which forest management processes should be included in the LCI for currently harvested birch (Betula spp.) roundwood in Latvia and based on these results compile the required data for the LCI. The results of forest management history analysis showed that for currently produced birch roundwood only logging operations should be included in the system boundary. Subsystems such as seed production, seedling production and silvicultural operations were not practiced or had only minor impact due to low mechanization level in the past. By taking into account the time-related factors, the LCI was developed and can be used in further calculations of environmental impacts for different wood-based products that are manufactured from currently harvested birch roundwood
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