1,720,954 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
Swedish –s-passives and Object Shift: Reference in the Syntax
No full textIn this project I attempt to shed light on an array of interacting syntactic phenomena
relating to the so-called morphological passive in Swedish. Its morpheme, -s, has
been assumed to be a voice morpheme, but in reality it has many of the interpretational
characteristics of a verb argument. I argue that a remnant movement analysis of Swedish
verb movement can accommodate for this morpheme’s distribution and interpretations
as a verb argument. This analysis offers an interesting perspective on the nature
of Object Shift in Scandinavian, which there has been practically no consensus on.
I will suggest that the distribution of Object Shift and -s are a part of a syntactic
process that apparently can access some reference properties of nominals.I have also
presented this paper at the TULCON undergraduate linguistics conference at the University
of Toronto, and at UW Linguistics' own Undergraduate Colloquium
Characterization of prostate tumor spheroid growth and response to treatment using dynamic optical coherence tomography
No full textProstate cancer, the most prevalent cancer in North American men, is often treated with radiation and in the case of advanced disease, with the first-line chemotherapeutic docetaxel (DTX). The use of in vitro cell culture as a model for in vivo patient tumors has been instrumental in understanding the cancer biology underpinning tumor development, progression, and treatment. Conventionally, in vitro cells were cultured as 2D monolayers on hard, flat surfaces. However, it has become well understood in the last half-century that the behavior of in vivo tumors is better replicated by small 3D aggregates of in vitro cancer cells called tumor spheroids. While cells proliferate along the spheroid periphery, the center of the spheroid succumbs to starvation and waste build up. In between forms an intermediate layer of hypoxic and non-proliferative quiescent cells: two characteristics associated with treatment resistance.
Despite the physiological pertinence of spheroid culture, its 3D nature challenges conventional biological methods. Moreover, cell culture geometry influences cell behavior not only during treatment, but in post-treatment recovery and throughout measurement as well. The clonogenic assay is a gold standard method for quantifying cell survival following treatment; however, it requires spheroids to be disaggregated and cultured in 2D for colony formation, which alters the cellular response. Proliferation assays quantify cellular activity inside intact spheroids, but similarly lack spatial resolution. Although fluorescence microscopy (FM) enables spatially resolved spheroid evaluation, it remains largely qualitative rather than quantitative. Proliferation assays and FM also require the addition of exogenous agents that are invasive to the sample and struggle to penetrate large spheroids. Alternatively, optical coherence tomography (OCT) enables non-invasive, high-speed, volumetric imaging of biological tissues with cellular resolution. Analysis of temporal OCT intensity fluctuations generates dynamic OCT (dOCT) images that can provide a quantitative and spatially resolved measurement of cellular activity throughout the spheroid.
Nevertheless, investigating treatment response in spheroids is known to be tedious and time consuming, and some questions of interest cannot be accessed experimentally with adequate accuracy. As such, mathematical in silico models of spheroids have become increasingly prevalent. The heterogeneity inherent to in vivo tumors and in vitro spheroids is recapitulated by discrete in silico methods like agent-based modeling (ABM). These methods simulate each cancer cell as an individual “agent” that responds to neighboring cells, nutrients, drugs, and other components of its local environment. In particular, the cellular Potts model (CPM) is a form of ABM with phenomenological utility, given adequate validation to experimental observations. As such, it can describe, visualize, interpolate, and potentially even extrapolate experimental data to guide future experiments.
This dissertation investigated and validated emerging and under-used in vitro tools for characterizing prostate tumor spheroid growth and response to treatment with radiation and DTX. First, I created a semi-automated masking process to isolate spheroids from volumetric OCT images for high resolution morphological analysis. For analysis of dynamic motion, I generated dOCT images using a frequency banding method that had only been previously subject to qualitative evaluation. Then, I developed a technique to quantify cellular activity in volumetric dOCT images of masked spheroids. Visual and quantitative comparison of live and formaldehyde-fixed spheroids imaged with dOCT and FM confirmed that dynamic motion measured with the dOCT method was associated with cellular activity. To mitigate influences unrelated to cellular activity, the average measurement of formaldehyde-fixed spheroids was subtracted from quantitative dOCT measurement as background. Post-treatment recovery of prostate tumor spheroids exposed to DTX was investigated with repeated measurement via Alamar Blue (AB) proliferation assay and longitudinal observation of clonogenic assay colony formation.
Excellent agreement was observed between the quantitative dOCT method and AB proliferation assay over two weeks of longitudinal spheroid growth. Volumetric morphological analysis supported the measured cellular activity trends. However, fixation-subtraction could not be performed in a spatially sensitive manner and the dOCT images failed to resolve the longitudinal formation of a necrotic spheroid core that was observed via FM. Nonetheless, dOCT images and quantification of spheroids post-radiation demonstrated good agreement with FM and AB, respectively. Spheroids treated with radiation and DTX demonstrated better survival compared to monolayer culture. Monolayer culture treated with low dose DTX demonstrated higher post-treatment cellular activity and faster colony formation, but clonogenic survival remained lower than the untreated control. This effect was also observed in spheroids, albeit to a lesser extent. Experimental observations were probed with novel in silico CPMs of prostate tumor spheroid treatment.
This thesis serves as a step towards validating emerging and under-used in vitro tools for spheroid evaluation in well-studied conventional cancer treatments. Once validated, these in vitro tools are particularly well suited for discovery and testing of novel targeted cancer treatments since spheroid protein and gene expressions are more physiologically representative than monolayer culture
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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