24,934 research outputs found

    White matter fiber-based analysis of T1w/T2w ratio map

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    Purpose: To develop, test, evaluate and apply a novel tool for the white matter fiber-based analysis of T1w/T2w ratio maps quantifying myelin content. Background: The cerebral white matter in the human brain develops from a mostly non-myelinated state to a nearly fully mature white matter myelination within the first few years of life. High resolution T1w/T2w ratio maps are believed to be effective in quantitatively estimating myelin content on a voxel-wise basis. We propose the use of a fiber-tract-based analysis of such T1w/T2w ratio data, as it allows us to separate fiber bundles that a common regional analysis imprecisely groups together, and to associate effects to specific tracts rather than large, broad regions. Methods: We developed an intuitive, open source tool to facilitate such fiber-based studies of T1w/T2w ratio maps. Via its Graphical User Interface (GUI) the tool is accessible to non-technical users. The framework uses calibrated T1w/T2w ratio maps and a prior fiber atlas as an input to generate profiles of T1w/T2w values. The resulting fiber profiles are used in a statistical analysis that performs along-tract functional statistical analysis. We applied this approach to a preliminary study of early brain development in neonates. Results: We developed an open-source tool for the fiber based analysis of T1w/T2w ratio maps and tested it in a study of brain development

    Jack Alive / Martin Dead : The Location of the "Author" in Jack London\u27s Martin Eden

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    This essay is an attempt to read Martin Eden, Jack Londonʼs autobiographical novel, in terms of the inextricable relationship between the author and the protagonist. Critics have often taken the unbalanced plot and the lack of ironic distance between narrator and character in Martin Eden as the technical weakness of London, but this paper argues that the achievement of this novel owes a great deal to the attachment of London to Martin. The unbalanced structure is a necessary product of the severe struggle of the author to kill his romantic alter ego. // Martin, who aspires to win Ruth Morse, tries to cross class boundaries by making a career of a writer. Even after realizing the emptiness of Ruth, who turns out to be nothing but a typical figure of the bourgeoisie, he somehow persists in loving her. The notion underlying here is that, for Martin, love, career and art are fundamentally inseparable. He objects to the aestheteʼs view of Brissenden on account of his separation of art from career. Martinʼs identity and life consist only in the triunity of love/career/art; the alternative is the repudiation of life. Thus, the unnatural delay of his disappointment in love can be regarded as Londonʼs strategy to set the suicide of Martin as the necessary consequence of the story. // By finishing the story and killing Martin, London finally detaches himself from Martin, reconstructs his self, and, unlike Martin, survives as a professional writer. In this sense, Martin Eden is a story about “writerʼs self-reconstruction.

    Robert Martin Tiffin's Mystery Man Newspaper Articles

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    Advertiser-Tribune newspaper clippings featuring a story about Robert Martin (written by Nancy Kleinhenz), a local author from Tiffin (Ohio) who wrote under the pseudonym of Lee Roberts, and two of his short stories. Martin wrote mystery novels in his spare time, creating more than 22 mystery novels. For more information about Robert Martin and a list of books go to http://www.mysteryfile.com/RMartin/JBennett.html

    Improved registration of DCE-MR images of the liver using a prior segmentation of the region of interest

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    In Dynamic Contrast-Enhanced MRI (DCE-MRI) of the liver, a series of images is acquired over a period of 20 minutes. Due to the patient's breathing, the liver is subject to a substantial displacement between acquisitions. Furthermore, due to its location in the abdomen, the liver also undergoes marked deformation. The large deformations combined with variation in image contrast make accurate liver registration challenging. We present a registration framework that incorporates a liver segmentation to improve the registration accuracy. The segmented liver serves as region-of-interest to our in-house developed registration method called ALOST (autocorrelation of local image structure). ALOST is a continuous optimization method that uses local phase features to overcome space-variant intensity distortions. The proposed framework can confine the solution field to the liver and allow for ALOST to obtain a more accurate solution. For the segmentation part, we use a level-set method to delineate the liver in a so-called contrast enhancement map. This map is obtained by computing the difference between the last and registered first volume from the DCE series. Subsequently, we slightly dilate the segmentation, and apply it as the mask to the other DCE-MRI volumes during registration. It is shown that the registration result becomes more accurate compared with the original ALOST approach.ImPhys/Quantitative Imagin

    Automatic estimation of retinal nerve fiber bundle orientation in SD-OCT images using a structure-oriented smoothing filter

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    Optical coherence tomography (OCT) yields high-resolution, three-dimensional images of the retina. A better understanding of retinal nerve fiber bundle (RNFB) trajectories in combination with visual field data may be used for future diagnosis and monitoring of glaucoma. However, manual tracing of these bundles is a tedious task. In this work, we present an automatic technique to estimate the orientation of RNFBs from volumetric OCT scans. Our method consists of several steps, starting from automatic segmentation of the RNFL. Then, a stack of en face images around the posterior nerve fiber layer interface was extracted. The image showing the best visibility of RNFB trajectories was selected for further processing. After denoising the selected en face image, a semblance structure-oriented filter was applied to probe the strength of local linear structure in a discrete set of orientations creating an orientation space. Gaussian filtering along the orientation axis in this space is used to find the dominant orientation. Next, a confidence map was created to supplement the estimated orientation. This confidence map was used as pixel weight in normalized convolution to regularize the semblance filter response after which a new orientation estimate can be obtained. Finally, after several iterations an orientation field corresponding to the strongest local orientation was obtained. The RNFB orientations of six macular scans from three subjects were estimated. For all scans, visual inspection shows a good agreement between the estimated orientation fields and the RNFB trajectories in the en face images. Additionally, a good correlation between the orientation fields of two scans of the same subject was observed. Our method was also applied to a larger field of view around the macula. Manual tracing of the RNFB trajectories shows a good agreement with the automatically obtained streamlines obtained by fiber tracking.ImPhys/Quantitative Imagin

    Experiences Using Large Scale Video Walls for Distance Education

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    We describe our experiences building and using the Rutgers Videowall, a low-cost telepresence system that has been used teaching 15 courses and colloquia. By relaxing typical spatial telepresence features, such as background continuity, we greatly reduced costs and gained flexibility in the rooms it could be deployed in. The lower costs and room flexibility enabled academic departments to use the wall, in contrast to traditional telepresence systems which remained inaccessible. We found that the Videowall’s spatial distortions did not have a significant impact on useability, as our initial survey results show that students had an overall positive experience.Technical report DCS-tr-72

    Hans Martin Schwarz Collection 1934 - 1938

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    This collection contains clippings of articles by Hans Martin Schwarz (1917, Hamburg – 2006, New York, better known as Martin Ebon), published between 1934 and 1938 in German-Jewish newspapers on a wide variety of subjects such as sports, emigration, the political situation in Germany, and religious attitudes of the young. It also contains reviews of his books "Einer wie Du und Ich" and "Heiteres, Besinnliches, Nachdenkliches."digitizedHans Martin Schwarz (1917, Hamburg – 2006, New York, better known as Martin Ebon), was a journalist and author. In Germany during the 1930s, he published in a variety of German-Jewish periodicals, primarily the Israelitisches Familienblatt. After immigrating to the United States in 1938, he changed his name to Martin Ebon, and published dozens of books in the areas of world affairs and parapsychology.Processe

    Interview with Father James Martin

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    In May 2011, the Ignatian Faculty Scholars at Regis University conducted a Skype interview with Father James Martin, S. J., author of The Jesuit Guide to Almost Everything. The Scholars had used Father Martin’s book as a text for their year of study, which focused on Ignatian Spirituality, the Ignatian Pedagogical Paradigm, and teaching and learning at a Jesuit university. The interview was transcribed and is printed below. Father Martin reflects on the book, and responds to questions about the book itself, about finding God in all learners, and about the Church
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