1,720,956 research outputs found
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
Translational Pharmacokinetic-Pharmacodynamic Modeling and Simulation in the Development of Spectinamides, a Novel Class of Anti-Tuberculosis Agents
Get PDFNew chemotherapeutic agents are urgently needed to control the spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR) forms of tuberculosis, which still remains an important public health challenge globally. Recently, spectinamides have emerged as a novel class of anti-tuberculosis agents that overcomethe native drug efflux. Spectinamides bind to the 30S bacterial ribosomal subunit which interferes with ribosomal translocation, and ultimately results in inhibition of protein synthesis. They have potent in vitro activity against drug resistant Mycobacterium tuberculosis (Mtb), and also demonstrated sustained efficacy in (Mtb)-infected mouse models. Pharmacokinetic (PK)/ pharmacodynamic (PD) analyses play a critical role in identifying the optimum dosing regimen for new treatments. In this dissertation, I hypothesized that the application of translational PK/PD modeling and simulation techniques would facilitate rational dosage regimen design for spectinamides.
To characterize the dose-exposure-response of Lee 1810, a dose-fractionation study was performed in BALB/c mice infected with a low dose aerosol of (Mtb). Dosing with different dosing regimens was continued for 4 weeks with two blood samples obtained from each mice in the last week, followed by a washout period after which the mice were sacrificed and the lungs removed for measurement of colony forming units (CFU). Drug concentrations in plasma were analyzed with a validated LC-MS/MS method followed by a population PK analysis which also included as anchor point the data of a PK study in healthy mice with intensive sampling. A model for natural bacterial growth in Mtb infection in untreated mice was built from data on the natural history of Mtb infection in mice obtained from previously performed studies and from the literature. Based on the individual post hoc estimates from the population PK modeling, a sequential PK/PD analysis was performed by linking the PK model with the bacterial growth model via an exposure-dependent bacterial kill function that included a sigmoid Emax model for describing the overall rate of change in lung CFU with different dosing regimens. A two-compartment model with first-order absorption was used to describe the pharmacokinetics of Lee 1810. The average absorption rate constant (Ka), clearance (CL/F), volume of the central compartment (Vc/F), intercompartmental clearance (Q/F), and volume of the peripheral compartment (Vp/F) was estimated to be 2.31 h-1,1.17 L/h/kg, 0.435 L/kg, 0.0191 L/h/kg, and 0.161 L/kg, respectively. The inter-individual variability in CL/F was estimated as 19.9 %. The pharmacokinetics of Lee 1810 was found to be different between healthy and infected mice with the later having 56.5% lower CL/F, 69% lower Vc/F and 69.6% lower Q/F. The two-subpopulation model could successfully describe the natural bacterial growth. The replication rate constant (Krep) of Mtb was calculated as 0.0327 h-1 which is consistent with values reported in the literature. The death rate constant induced by the immune system (Kir) was 0.00303 h-1, cell countof fast growing population at the initiation of the infection (N1,0) was 1.93 Log CFU and maximum number of bacteria (Nmax) was 6.44 Log CFU. The inter-individual variability in Krep and Nmax was estimated as 70.8 % and 54.7%, respectively. The bacterial kill induced by the drug was described using a sigmoid Emax model. The drug effect parameters (EC50), maximum kill rate (Emax) and Hill coefficient (y), were estimated as 239 μg/mL, 11.9 h-1 and 2.40 respectively. A Hill coefficient substantially greater than 1 is a typical characteristic of concentration-dependent killing. The concentration dependent killing characteristic of Lee 1810 supports its intermittent dosing.
Poor permeability of spectinamides across the gut limits its oral use. Additionally, since the lungs are the main site of infection in pulmonary TB, the efficacy of lead spectinamide Lee 1599 was evaluated after intratracheal (IT) administration in a mouse model of Mtb infection. A dose of 200 mg/kg TIW (3 days a week) for 28 days resulted in excellent efficacy with 2.2 Log CFU reduction in the lungs. Based on these observations, a comparative biodistribution study of Lee 1599 was performed after IT and SC administration in mice. Plasma and tissue samples were collected at pre-specified time points. The drug was extracted from plasma and homogenized tissues after protein precipitation and analyzed with an LC-MS/MS assay. The rate and extent of absorption was almost two times higher with IT as compared to SC administration. As expected, the highest exposure of Lee 1599 after IT administration was attained in the lungs, which was 2.5 times higher than in plasma. This is highly desirable as lungs are the main site of infection in pulmonary tuberculosis. Overall, this study supports the pulmonary route as a potential pathway for the treatment of tuberculosis with Lee 1599.
Physiologically-based pharmacokinetic (PBPK) modeling and simulation is a powerful methodology used in support of dose selection for first-in-human studies. The objective was to develop a PBPK model for describing pharmacokinetics of Lee 1599 in rats and mice, and to extrapolate this PK behavior to humans. 10 mg/kg of Lee 1599 was administered intravenously to rats and 200 mg/kg subcutaneously to mice. The PBPK model was developed based on the observed rat plasma concentrations, physicochemical properties of Lee 1599, and in vitro data from its metabolism, protein binding and permeability. The concentration-time profile of Lee 1599 in rats was well described by the optimized PBPK model. The model was prospectively qualified by PBPK scaling from rats to mice and comparing predicted murine concentration-time profiles to observed plasma concentrations. This model was also successful in predicting murine PK with observed PK parameters within two-folds of predicted values. The model predicted, weight normalized human clearance of 0.25 L/h/kg was as expected less than the values in rats (0.666 L/h/kg) and mice (1.25 L/h/kg). The PBPK model predicted, a dose of 7.5 mg/kg and 27.5 mg/kg administered once daily via intravenous administration will be required to attain similar exposure as observed in mice after subcutaneous administration of 50 mg/kg and 200 mg/kg respectively. This model suggests that an efficacious systemic exposure can be achieved with daily doses feasible in humans, and may be useful during drug development for understanding the dose requirements for future human studies.
In conclusion, translational PK/PD approaches have been successfully used for the further development and characterization of spectinamides leads Lee 1599 and Lee 1810. The results from the above studies will be helpful in identifying and optimizing the dosing regimens which can strike a balance between bacterial reduction, adverse effects, and emergence of resistance
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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