1,721,168 research outputs found
Data acquired to demonstrate model-based Bayesian inference of brain oxygenation using quantitative BOLD
No full textThis dataset will form the basis of a forthcoming publication regarding a model-based Bayesian analysis of streamlined quantitative BOLD data to measure brain oxygenation. In the absence of a reference to this publication the methods used are outlined here. Please reference this dataset if you use it in your work.
Cherukara MT, Stone AJ, Chappell MA, Blockley NP. Data acquired to demonstrate model-based Bayesian inference of brain oxygenation using quantitative BOLD, Oxford University Research Archive 2018. doi: 10.5287/bodleian:6R5px9K0X
*Summary*
Data for Study 1 (7 subjects) of this dataset were acquired as part of a previous study [1] and are also available at via the Oxford University Research Archive [2]. Data for Study 2 (5 subjects) were acquired to demonstrate and validate a model-based Bayesian analysis method of similar data. The aim in this part was to see whether a model-based correction for CSF signal, using an independent CSF partial volume estimate, could be used in place of a FLAIR preparation [3] in order to improve image SNR and reduce total scan time. Images were acquired the streamlined qBOLD protocol [1] both with and without FLAIR preparation, using an Asymmetric Spin Echo (ASE) pulse sequence [4] with Gradient Echo Slice Excitation Profile Imaging (GESEPI) incorporated to minimise the effect of through-slice magnetic field gradients [5].
*MRI data*
Images were acquired using a Siemens Magnetom Verio scanner at 3T. The body coil was used for transmission and the manufacturer's 32-channel head coil was used for reception. For Study 1, GESEPI ASE (GASE) data were acquired with a field of view of 240x240 mm2, a 64x64 matrix, ten 5mm slices, TR/TE=3s/74ms, and an EPI bandwidth of 2004Hz/px. ASE images are acquired with varying amount of R2′ weighting determined by the spin echo displacement time, tau. Twenty four values of tau were acquired for each GASE scan: -28, -24, -20, -16, -12, -8, -4, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, and 64ms. For Study 2, GASE data were acquired with a 220x220 mm2 field of view, a 96x96 matrix, eight 5mm slices, TR/TE=3s/82ms, an EPI bandwidth of 2004Hz/px, and eleven tau values: -16, -8, 0, 8, 16, 24, 32, 40, 48, 56, and 64ms. For all subjects, the GESEPI magnetic field gradient correction technique required each 5mm slice to be encoded into multiple thin partitions each 1.25mm thick. Furthermore, partitions were oversampled by 100% leading to the acquisition of 8 partitions per slice. Oversampled slices were discarded during reconstruction, resulting in 40 slices being acquired for each tau value. To regain signal to noise ratio summing the slices in blocks of four is suggested. This results in the original number of prescribed slices. A FLAIR preparation was used to null the signal from CSF, with an inversion time of 1.21s, based on literature values for T1 and T2 of CSF [3]. In Study 2, GASE data were also acquired with the same protocol but without the FLAIR preparation, as well as a single GASE volume with the same parameters, except with a TE of 250ms, and tau of 0ms, and a set of eight 2D spin echo volumes with the same dimensions as the GASE data were acquired with TE values uniformly spaced from 66 to 248 ms. These were used to generate T2 weighted estimates of CSF partial volume. High resolution T1 weighted anatomical images were acquired for registration and the generation of tissue masks and T1 weighted CSF partial volume estimates. Anatomicals were “defaced” using the shell script in the code directory [6].
*Data curation*
The structure in which this data has been placed is based on the Brain Imaging Data Structure (BIDS) format [7]. However, this format (BIDS version 1.0.0-rc2) does not support ASE data, but we have followed the guiding principles of this specification.
*References*
1. Stone AJ, Blockley NP. A streamlined acquisition for mapping baseline brain oxygenation using quantitative BOLD. NeuroImage 2017:147:79-88.
2. Stone AJ, Blockley NP. Data acquired to demonstrate a streamlined approach to mapping and quantifying brain oxygenation using quantitative BOLD. Oxford University Research Archive 2016. doi: 10.5287/Bodleian:E24JbXQwO.
3. Hajnal JV, Bryant DJ, Kasuboski L, Pattany PM, De Coene B, Lewis PD, Pennock JM, Oatridge A, Young IR, Bydder GM. Use of fluid attenuated inversion recovery (FLAIR) pulse sequences in MRI of the brain. J Comput Assist Tomogr
1992;16:841–844.
4. Wismer GL, Buxton RB, Rosen BR, Fisel CR, Oot RF, Brady TJ, Davis KR. Susceptibility induced MR line broadening: applications to brain iron mapping. J Comput Assist Tomogr 1988;12:259–265.
5. Blockley NP, Stone AJ. Improving the specificity of R2′ to the deoxyhaemoglobin content of brain tissue: Prospective correction of macroscopic magnetic field gradients. Neuroimage 2016, in press. doi: 10.1016/j.neuroimage.2016.04.013
6. https://github.com/hanke/gumpdata/blob/master/scripts/conversion/convert_dicoms_anatomy
7. http://bids.neuroimaging.i
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
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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