1,720,992 research outputs found
A novel method to evaluate nutrient retention by biological soil crust exopolymeric matrix
No full textAimsBiological soil crusts (biocrusts) are microbial communities commonly found in the upper layer of arid soils. These microorganisms release exopolysaccharides (EPS), which form the exopolymeric matrix (EPM), allowing them to bond soil particles together and survive long periods of dryness. The aim of this work is to develop methods for measuring metabolite retention by biocrust EPM and EPS.MethodsWe report new methods for the investigation of metabolite sorption on biocrusts compared to the underlying unconsolidated subcrust fraction. A 13C–labeled bacterial lysate metabolite mixture was incubated with biocrust, subcrust and biocrust-extracted EPS. Non-sorbed metabolites were extracted and analyzed by liquid chromatography/mass spectrometry.ResultsThis simple and rapid approach enabled the comparison of metabolite sorption on the biocrust EPM or EPS versus mineral sorption on the underlying soils. Our results suggest that the biocrust (and its extracted EPS) sorb more metabolites, especially amino acids and organic acids, than the underlying subcrust.ConclusionsThis study demonstrates a useful method to highlight the essential role of biocrust (especially the EPM), which acts as a passive nutrient filter, sequestering metabolites released by microbes during wetting events. This may facilitate recovery of the community upon wetting and further enhance biocrust survival and nutrient retention
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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
No full textWe 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
No full textWe 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
Prescription Drug Adherence and Cost-Related Underuse in the Medicare Population
No full textUniversity of Minnesota Ph.D. dissertation.March 2016. Major: Health Services Research, Policy and Administration. Advisors: Kathleen Call, Pinar Karaca-Mandic. 1 computer file (PDF); ix, 198 pages.Underuse of medical care and prescription drug adherence are health behaviors affected by financial pressures, demographic and socioeconomic characteristics, and health status of Medicare beneficiaries. Cost-related underuse is the avoidance of needed medical care or prescription drugs due to financial concerns about the cost of the treatment. The purpose of this project is to determine the characteristics associated with cost-related underuse and to evaluate how health policy changes and prescription drug coverage may affect that behavior. The project aims are threefold: (1) determine the change over time and relationship between prescription drug coverage and the underuse of other medical care due to cost within the Medicare population; (2) examine the effect of enrollment in the Medicare Part D partial Low Income Subsidy (LIS), a program that provides scaled premium assistance and a flat 15% co-insurance, on adherence within drug classes associated with cost-related underuse; and (3) test the effects of financial, patient, and disease characteristics on prescription drug adherence within the Medicare partial LIS population. This study will provide a broader understanding of the policy levers, such as the Medicare Part D Low Income Subsidy, that impact prescription drug behavior and underutilization of medical care by Medicare beneficiaries.Swenson, Tami. (2016). Prescription Drug Adherence and Cost-Related Underuse in the Medicare Population. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/196523
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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