1,720,963 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
Quantitative Magnetic Resonance Imaging For The Early Prediction of Treatment Response In Triple Negative Breast Cancer
Get PDFTriple Negative Breast Cancer (TNBC) is an aggressive subtype of breast cancer which lacks upregulated hormone receptors. Because of this, it is not vulnerable to clinically available targeted therapies. When treated with standard of care neoadjuvant systemic therapy (NAST), TNBC only shows approximately a 40% rate of pathologic complete response (pCR). A biomarker which could predict TNBC response to NAST early during treatment would be useful, as it would allow for non-responders to be triaged to alternative therapies and potentially allow for the treatment of responders to be de-escalated.
Quantitative Magnetic Resonance Imaging (MRI) may be used to probe and measure aspects of the perfusion, diffusion, and mechanical properties of a cancer and its surroundings. In the research setting, several quantitative MRI biomarkers have shown potential for early prediction of response in breast cancer. However, TNBC shows a unique image phenotype on both conventional MRI and MRI biomarkers of response. Several MRI biomarkers of response which show promise in other breast cancer subtypes are not useful for predicting response in TNBC. This, in combination with the clinical needs of TNBC, warrants the development of MRI biomarkers of response that are specific to TNBC. This rational supports a large, ongoing prospective trial of TNBC patients at our institution who underwent longitudinal multiparametric MRI at pretreatment, after 2 cycles of NAST and after 4 cycles of NAST. In this dissertation, MRI biomarkers from diffusion MRI, dynamic contrast-enhanced (DCE) MRI, and magnetic resonance elastography (MRE) were developed and applied as predictors of NAST response in the prospective trial cohort.
First, aspects of the tumor necrosis on pretreatment diffusion MRI and DCE MRI were investigated as potential predictors of response. Our study established that no associations were present between tumor necrosis and the treatment response in our study population, thus served as a caution in the field for physicians considering necrosis on MRI as a possible negative predictive biomarker.
Second, functional tumor volume (FTV), an existing biomarker of response in breast cancer based on DCE MRI contrast thresholds, was optimized for early prediction of NAST response in TNBC. Fast DCE MRI from pretreatment and cycle 4 MRI scans was leveraged to find an optimal contrast timing to improve the predictive performance of FTV. FTV contrast thresholds optimized over the TNBC cohort paralleled TNBC subtype analysis presented by other groups in previous reports. This external validation further supports the use of a TNBC-specific FTV tuning for prediction of NAST response.
Third, diffusion MRI measurements in the peritumoral region were developed and applied as predictors of NAST response. We found that maximum diffusion and the standard deviation of diffusion in peritumoral regions including fatty tissues were useful for prediction of NAST response.
Finally, a convolutional neural network (CNN)-based MRE inversion algorithm was developed for improved spatial resolution of breast cancer MRE. Because acquisition of ground truth MRE data is impossible, simulating MRE data via finite volume methods (FVM) was substituted in CNN training. The CNN-based inversion algorithm was validated through gel phantom measurements. Validation on in vivo breast MRE was performed by comparing stiffness measurements from different breast tissues between the CNN-based algorithm and the existing vendor algorithm. Both algorithms were able to effectively distinguish between the tumor and other breast tissues, though only the vendor algorithm was able to distinguish between fatty tissue and fibroglandular tissue.
In conclusion, quantitative MRI biomarkers of breast cancer were developed and show promise for early prediction of NAST response in TNBC. MRI biomarkers of necrosis were not seen to be useful, while TNBC-tuned FTV and diffusion MRI of the peritumoral region showed promise for this purpose. A CNN-based inversion algorithm shows potential for MRE with improved spatial resolution, though additional development is required
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
Quantitative Dwi As An Early Imaging Biomarker of The Response to Chemoradiation In Esophageal Cancer
Get PDFFor patients diagnosed with stages IIa-IIb esophageal cancer, the current standard of care treatment is tri-modality therapy (TMT), where neoadjuvant chemoradiation (nCRT) is followed by surgical resection. Histopathology of resected tumors reveals that pathological complete response (pCR) is achieved in 20-30% of patients through nCRT alone. Because of the high mortality and morbidity associated with esophagectomy, it may be advantageous for patients exhibiting pCR from nCRT alone to be placed under observation rather than completing their TMT. Therefore, a method for predicting response at an early time-point during nCRT is highly desirable. Conventional methods such as endoscopic ultrasound, re-biopsy, and morphologic imaging are insufficient for this purpose. During nCRT, morphologic changes in tumors are often preceded by changes in the tumor biology. Diffusion Weighed Imaging (DWI) is an MRI modality which is sensitive to microscopic motion of water molecules in tissue. Quantitative DWI provides a measure of the cellular microenvironment which is impacted by cellularity, extra-cellular volume fraction, structure of the extracellular matrix, and cellular membranes. This work sought to investigate if changes in quantitative DWI may be used as an early imaging biomarker for the prediction of response to nCRT in esophageal cancer.
DWI scans were performed on a small group of esophageal cancer patients (stages IIa to IIIb) before, at interim, and after completion of their nCRT. Quantitative diffusion parameter maps were estimated for DWI scans using the following models of diffusion: mono-exponential, intra-voxel incoherent motion (IVIM), and kurtosis. Summary measures of quantitative diffusion parameters were extracted from tumor voxels through volumetric contouring. These summary measures were retrospectively compared between histopathologically confirmed groupings of patients as pCR and non-pCR. The study found that the relative change in mean ADC could completely separate groupings of pCR and non-pCR patients (AUC=1) at a cutoff of 27.7%. Measurement by volume contouring was shown to be highly reproducible between readers. This pilot study demonstrates the promise of using DWI for organ sparing approaches after nCRT in esophageal cancer
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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