14,984 research outputs found
Evaluation of atlas-based segmentation of hippocampi in healthy humans
No full textIntroduction and aim: Region of interest (ROI)-based functional magnetic resonance imaging (fMRI) data analysis relies on extracting signals from a specific area which is presumed to be involved in the brain activity being studied. The hippocampus is of interest in many functional connectivity studies for example in epilepsy as it plays an important role in epileptogenesis. In this context, ROI may be defined using different techniques. Our study aims at evaluating the spatial correspondence of hippocampal ROIs obtained using three brain atlases with hippocampal ROI obtained using an automatic segmentation algorithm dedicated to the hippocampus.
Material and methods: High-resolution volumetric T1-weighted MR images of 18 healthy volunteers (five females) were acquired on a 3T scanner. Individual ROIs for both hippocampi of each subject were segmented from the MR images using an automatic hippocampus and amygdala segmentation software called SACHA providing the gold standard ROI for comparison with the atlas-derived results. For each subject, hippocampal ROIs were also obtained using three brain atlases: PickAtlas available as a commonly used software toolbox; automated anatomical labeling (AAL) atlas included as a subset of ROI into PickAtlas toolbox and a frequency-based brain atlas by Hammers et al. The levels of agreement between the SACHA results and those obtained using the atlases were assessed based on quantitative indices measuring volume differences and spatial overlap. The comparison was performed in standard Montreal Neurological Institute space, the registration being obtained with SPM5 (http://www.fil.ion.ucl.ac.uk/spm/).
Results: The mean volumetric error across all subjects was 73% for hippocampal ROIs derived from AAL atlas; 20% in case of ROIs derived from the Hammers atlas and 107% for ROIs derived from PickAtlas. The mean false-positive and false-negative classification rates were 60% and 10% respectively for the AAL atlas; 16% and 32% for the Hammers atlas and 6% and 72% for the PickAtlas.
Conclusion: Though atlas-based ROI definition may be convenient, the resulting ROIs may be poor representations of the hippocampus in some studies critical to under- or oversampling. Performance of the AAL atlas was inferior to that of the Hammers atlas. Hippocampal ROIs derived from PickAtlas are highly significantly smaller, and this results in the worst performance out of three atlases. It is advisable that the defined ROIs should be verified with knowledge of neuroanatomy before using it for further data analysis
Individual-level molecular connectivity of GABAA receptors: assessing the similarity of [11C]Ro15-4513 kinetics across brain regions
No full textDouglas Alexander Stewart, poet, author and playwright
No full textDouglas Alexander Stewart, poet, author and playwrigh
Author inscription in William Hazlitt, essayist and critic; selections from his writings, with a memoir, biographical and critical by Alexander Ireland
No full textAuthor's gift inscription, "To W. C. Hazlitt Esq with kind regards, from Alexr Ireland," with tipped-in review of the book.ASU Library edition has inscription from Ireland to Hazlitt [a child of William Hazlitt?].
Hazlitt , William, 1778-1830.
Ireland, Alexander, 1810-1894
The Author of the Alexander Romance
No full textThis paper, which is based on a portion of the introduction of the author’s edition of Il Romanzo di Alessandro (Mondadori: Fondazione Valla 2007), surveys the generic components of the Alexander Romance in an attempt to arrive at a definition of the work. The argument builds on Merkelbach’s categorisation of elements and uses Fusillo’s insight into the novel as an ‘encyclopaedic genre’ to propose that ‘historical novel’ is not, as Hägg contended, a misnomer for the work. The main components I discuss are: ‘life’; praxeis; chreiai; Cynic elements, including choliambic poetry and utopian perspectives; and the Egyptian aspects of the narrative. A concluding jeu d’esprit offers a characterisation of the putative author, his antecedents and his process of composition.Richard Stoneman was for 25 years editor for classics at Croom Helm and then Routledge. In 1997 he was appointed an Honorary Fellow in the department of classics, University of Exeter. After retiring from publishing in 2006 he has been pursuing his researches on the Alexander legends and teaching a course on the subject at Exeter. His Penguin translation of the Alexander Romance was published in 1991, and a volume of translated Legends of Alexander the Great appeared from Everyman in 1994. Also in 1994 he co-edited Greek Fiction with John Morgan. His edition of the Greek recensions of the Alexander Romance was published (volume I) by the Fondazione Valla in 2007 – volumes II and III will follow over the next few years – and his Alexander the Great: A Life in Legend appeared from Yale University Press in spring 2008. He is the author of a number of other books on Greek history and travel, and is writing a book on oracles
Author Correction: The dengue-specific immune response and antibody identification with machine learning
No full textCorrection to: npj Vaccineshttps://doi.org/10.1038/s41541-023-00788-7, published online 20 January 2024 In this article, the affiliation details for author Alexander Horst were incorrectly given as Alexander Horst1,2 but should have been Alexander Horst1 and other affiliations are renumbered. The original article has been corrected
Alexander Woollcott, author and stage actor
No full textAlexander Woollcott, author and stage actorTo order a reproduction, inquire about permissions, or for information about prices see:
http://www.lib.washington.edu/specialcollections/services/reproduction/reproduction
Please cite the Order NumberScanned at 600ppi with an Epson 20000 flatbed scanner. Image then rotated, cropped, level-adjusted, and sharpened using Photoshop CS3. Converted to a JPEG2000 image upon ingest into CONTENTdm
Lori Alexander: Cook Prize 2025, Silver Medal Acceptance Speech
No full textAuthor Lori Alexander gives an acceptance speech for Cactus Queen: Minerva Hoyt Establishes Joshua Tree National Park (Calkins Creek)https://educate.bankstreet.edu/cook/1017/thumbnail.jp
Can visual illustrations transform the patient information sheet for PET/MR neuroimaging studies into an engaging and interesting reading?
Full text linkEvery research study with human participants requires a participant information sheet (PIS). This is an important document that aims to provide to the study participants, a full description of the study and all procedures, individual risks, and research benefits. But besides its informative use, the PIS also provides the legal basis for an individual to consent to participate and must be agreed and signed prior to participation
Catwalks and Collecting: Alexander Fury on Westwood and Galliano
No full textFashion journalist, author, and critic Alexander Fury and MFIT Curator Colleen Hill discussed Fury’s latest book, Vivienne Westwood: The Complete Collections (Yale University Press, 2021). The conversation included an overview of highlights from Fury’s personal collection of fashion, which includes designs by Westwood, John Galliano, Christian Lacroix, among others
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