1,721,064 research outputs found
On comparisons of time-domain scattering schemes
No full textNguyen, Brian T.. (1998). On comparisons of time-domain scattering schemes. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/3182
The Characterization of Circular Extrachromosomal rDNA Elements in Naegleria SPP
No full text2024ABSTRACT Naegleria are unicellular, eukaryotic amoebas characterized by their ability to shift between multiple life stages. These organisms are ubiquitous in nature and found in bodies of freshwater and soil. The Naegleria life stages include: the trophozoite stage, a growth and replication stage characterized by pseudopodic movement, the cyst stage, a hibernation stage characterized a double-walled membrane, and the flagellate stage, a mobility stage that is characterized by the presence of flagella. Naegleria are predominantly non-pathogenic except for Naegleria fowleri, which is the only species of Naegleria to cause disease in humans. Organisms of the Naegleria genus are further characterized by a circular extrachromosomal rDNA element (CERE) that is localized to the nucleolus. The CERE is unique because it contains the genes for rDNA production, which are not found in the chromosome. Naegleria species contain thousands of copies of the CERE which can replicate autonomously and independently of the chromosome. To date, the full-length CERE sequences were only known for different strains of N. gruberi, N. fowleri, and N. lovaniensis.
We investigated the CERE further by studying N. gruberi and other Naegleria species that represent varying levels of phylogenetic relatedness to N. gruberi: N. australiensis, N. jadini, and N. pringsheimi. Long-read sequencing of these CERE demonstrated a unique sequence composition for each species, predominantly within the non-ribosomal sequence (NRS). Sequencing revealed sizes ranging from 11.8 kbp in N. jadini up to 16.1 kbp in N. pringsheimi. Analysis of the full-length CERE indicate potential shifts in phylogenetic relatedness between species as well as the presence of predicted structures such as G-quadruplexes that are both unique and conserved across the genus.
We further explored the molecular dynamics of the N. gruberi CERE by transfecting cells with the molecular clone, pGRUB. Transfection with pGRUB demonstrated transient propagation across several culture passages, encystment and excystment. N. gruberi trophozoites transfected with constructs that either have or do not have the putative ori demonstrated diminished propagation, indicating other components of the NRS may be necessary for replication.
The objectives of this research were to provide further understanding of the Naegleria CERE and to significantly contribute to the Naegleria sequence database. The data from these results will function as a basis study the characteristics of N. fowleri and non-pathogenic Naegleria
Solitary waves in the critical surface tension model
No full textLi, Yi A.; Nguyen, Brian T.; Olver, Peter J.. (1998). Solitary waves in the critical surface tension model. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/3183
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
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
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
- …
