1,720,998 research outputs found
Evaluation of Duration of Immunity for Erysipelothrix Rhusiopathiae
No full textLehr, Craig; Erskine, Jason; Drake, Cristy; Bailey, Dale; Jayappa, H.; Wasmoen, Terri. (2004). Evaluation of Duration of Immunity for Erysipelothrix Rhusiopathiae. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/159971
Nature's genes in space and time: using DNA to uncover the history and formation of biodiversity.
No full textUniversity of Minnesota Ph.D. dissertation. August 2011. Major: Ecology, Evolution and Behavior. Advisor: Robert Zink. 1 computer file (PDF); vii, 108 pages.Modern science is tasked with explaining biological diversity: where it is, where it comes from, and how it evolves. Molecular tools have revolutionized this endeavor and given us the ability to peer into the evolutionary past like never before. Drawing on examples from the birds and mammals of East Asia, I present a progression of methods for uncovering the history and formation of species using molecular approaches. Because the characterization of diversity must necessarily precede the study of diversity, I begin in Chapter 1 with a species delimitation study aimed at resolving evolutionary lineages. I conclude that fixed character differences are better indicators of lineage limits than statistical approaches and that both morphological and molecular characters may be necessary to reveal lineages when divergence is recent. In Chapter 2 I describe the evolutionary history of a single-species in which I found evidence for a recent range-wide demographic expansion. This particular example demonstrates how phylogeography and ecological niche modeling can reciprocally illuminate aspects of evolutionary history. Finally, in Chapter 3 I discuss a comparative study of the evolutionary histories of multiple co-distributed species. Comparative studies reveal the generalities involved in evolution and allow us to discern the major drivers of biological diversity.McKay, Bailey Dale. (2011). Nature's genes in space and time: using DNA to uncover the history and formation of biodiversity.. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/116028
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
18F-dopa PET evidence that tolcapone acts as a central COMT inhibitor in Parkinson's disease
No full textTolcapone is a potent, selective, and reversible inhibitor of cathecol-O-methyl-transferase (COMT). This enzyme plays a crucial role in the extraneural inactivation of catecholamine neurotransmitters. Tolcapone's ability to inhibit central COMT in humans at therapeutic concentrations is not yet clear. The aim was to determine the effect of tolcapone on central COMT activity in Parkinson's disease (PD) using 18F-dopa positron emission tomography (PET). The study was a randomized two-way crossover study. Twelve PD patients were recruited. On the treatment days patients were given either tolcapone (200 mg) or placebo together with levodopa/carbidopa (100/125 mg) 1 h before the injection of 18F-dopa. Data were acquired in 25 frames over 94 min for the first PET scan period. At the end of this period the patients were removed from the scanner for 90 min and subsequently repositioned and data acquired in six 10-min time frames over 60 min. Influx constants (Ki) were computed using a graphical approach with a plasma input function. Mean 18F-dopa putamen Ki's for the first 30-90 min, primarily reflecting central dopa decarboxylase (DDC) activity, were similar in PD patients whether tolcapone was present (0.0078 ± 0.0031 min-1) or absent (0.0078 ± 0.0030 min-1). Mean putamen Ki values calculated 180-240 min after injection of 18F-dopa, reflecting both central DDC and COMT activity, were unchanged from 30-90′ values in the presence of tolcapone (0.0079 ± 0.0030), implying blockade of central COMT, but were significantly reduced (0.0059 ± 0.0028) in the absence of this drug. These findings are compatible with clinical doses of tolcapone having a significant blocking effect on peripheral and central COMT but not DDC activity in PD. © 2002 Wiley-Liss, Inc
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
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