363 research outputs found
Extended Figures TE Repetition Suppression
No full textExtended Data including individual-animal results for Nathaniel Williams and Carl Olson, Contribution of Individual Features to Repetition Suppression in Macaque Inferotemporal Cortex </p
Supplemental Methods V2 TE
No full textImages used in the study: Independent Repetition Suppression in Macaque Area V2 and Inferotemporal Cortex, Nathaniel Williams and Carl R. Olson</p
Mechanistic Investigations into the Palladium-Catalyzed Decarboxylative Allylic Alkylation of Ketone Enolates Using the PHOX Ligand Architecture
No full textPalladium-catalyzed asymmetric allylic alkylation has become a large and important field for chemical synthesis. Many methodologies in this field offer mild conditions under which challenging and important molecular features can be reliably synthesized, including chiral all-carbon quaternary stereocenters. As a result, palladium- catalyzed asymmetric allylic alkylation has found significant use in total synthesis, and growing use in industry. While the general process of palladium-catalyzed asymmetric allylic alkylation has been studied for decades, there have been a number of recent modifications and developments, such as asymmetric versions of decarboxylative allylic alkylation procedures that are not yet well understood. The development of future implementations and improvements to palladium-catalyzed asymmetric allylic alkylation and related methodologies is expected to be facilitated by a better understanding of these more recent developments, and thus further mechanistic investigation is warranted.
Reported herein is a set of investigations into the palladium-catalyzed decarboxylative asymmetric allylic alkylation of ketone enolates using the PHOX ligand architecture. By monitoring the reaction via 31P NMR, a series of previously unidentified key intermediates is discovered. Two representatives of these key intermediates are isolated and characterized. The solution behavior of these species under reaction-like conditions is studied along with a few novel and related complexes. The role of these intermediates and their impact on the behavior of the reaction and product formation is discussed. Previously confounding experimentally observed behavior for this methodology is rationalized via the properties elucidated for these discovered intermediates.</p
Planting the Union Flag in Texas: The Campaigns of Major General Nathaniel P. Banks in the West
No full textNathaniel Banks in Texas Over the years Gary Joiner and others have offered examinations of various parts of General Nathaniel P. Banks’s Western command in the latter years of the Civil War; comes now a full review of Banks’s activities by Stephen A. Dupree. The author\u27s efforts remin...
Juvenile poems on various subjects. With The prince of Parthia, a tragedy. / By the late Mr. Thomas Godfrey, Junr. of Philadelphia. ; To which is prefixed, some account of the author and his writings. ; [One line from Horace]
No full textxxvi, [2], 223, [1] p. ; 23 cm. (4to)"The Prince of Parthia is the earliest dramatic production by a native American author published in the American colonies."--Evans.The account of Godfrey is by Nathaniel Evans.Subscribers' names, p. xxiii-xxvi.Errata, p. [xxviii]."Elegy, to the memory of Mr Thomas Godfrey."--p. 1-4, signed: J. [i.e., John] Green. "Elegy to the memory of the same."--p. 5-7, signed: N. [i.e., Nathaniel] Evans
Uma senhora e um remador : presenças portuguesas na ficção de Nathaniel Hawthorne e Herman Melville
No full textIn this study the author analyses the relevance of the Portuguese presence in Nathaniel Hawthorne's "Drowne Wooden Image" and Herman Melville's "Benito Cereno", taking into account the historical, cultural, and literary context of their work
Quantifier rank spectrum of L-infinity-omega
No full textThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2006.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 321) and index.In Part A we will study the quantifier rank spectrum of sentences of L!1,!. We will show that there are scattered sentences with models of arbitrarily high but bounded quantifier rank. We will also consider the case of weakly scattered and almost scattered sentences, and we will make some conjectures. In Part B we will look at a new method of induction in the case of sheaves. We will then use this method to generalize the classical proof of the Suslin-Kleene Separation Theorem to the context of sheaves on a partial Grothendieck topology.by Nathaniel Leedom Ackerman.Ph.D
Radiocarbon measurements in the Indian Ocean aboard RVIB Nathaniel B. Palmer
No full textAuthor Posting. © The Oceanography Society, 2012. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 25, no. 3 (2012): 152-153, doi:10.5670/oceanog.2012.89.Research Vessel Icebreaker Nathaniel B. Palmer departed Cape Town, South Africa, on May 3, 1996, to complete the Indian Ocean portion of the "S04" line, a circumnavigation of Antarctica that was part of the US contribution to the World Ocean Circulation Experiment (WOCE). The WOCE Line S04I voyage ended at Hobart, Tasmania, on July 4, 1996, following completion of 108 stations, despite suspension of science operations for seven days on June 8, when the Palmer was diverted to deliver emergency food supplies to Russia's Mirny Station in the Davis Sea. During this extreme south cruise, with Thomas Whitworth III (Texas A&M University) and James H. Swift (Scripps Institution of Oceanography) as co-chief scientists, a total of 816 radiocarbon samples were collected by author Key at 31 stations, and these samples were later analyzed by author McNichol at the National Ocean Sciences Accelerator Mass Spectrometry Facility at the Woods Hole Oceanographic Institution
Music for classical guitar by South African composers : a historical survey, notes on selected works and a general catalogue
No full textIncludes abstract.Includes bibliographical references (leaves 296-309).This is the first comprehensive investigation of music for, or including, the classical guitar by South African composers. The focus of this research has been, firstly, to uncover as much of the repertoire as possible, and, secondly, to collate, study, catalogue and report on the information. A brief historical survey of the guitar in South Africa provides the context within which this study was conducted. The primary sources of quantitative data collection were through the archival catalogues of the South African Music Rights Organisation and through personal contact with guitarists, composers and guitar teachers. Other sources consulted were publishers, broadcasting corporations, recording companies, libraries and the internet. The body of the dissertation comprises biographical sketches, background notes, analyses and technical notes on 17 selected solo and chamber works dating from 1947 to 2007 by some of South Africa's most prominent composers and guitaristcomposers. The repertoire ranges in style from the traditional and ethnically inspired to the experimental and abstract. As this is an empirical survey, each selected entry includes details on instrumentation, duration, level of difficulty, number of pages, scordatura, commissions or requests, sources or publishers, premières and recordings. A biography of each composer is provided as well as background notes which offer an overview of the selected work. The notes discuss historical, cultural, musical and extra-musical influences, and frequently include references to interview material. The commentaries on the selected works, with musical examples, include an analytical component describing structure, form, stylistic and compositional elements, while the technical observations include performance suggestions and a grading for each work
Discovering underlying forms: contrast pairs and ranking
No full textPhonological learners must acquire a lexicon of underlying forms and a constraint ranking. These must be acquired simultaneously, as the ranking and the underlying forms are interdependent. Exhaustive search of all possible lexica is intractable; the space of lexica is simply too large. Searching the underlying forms for each overt form in isolation poses other problems. A single overt form is often highly ambiguous among both underlying forms and rankings. In this dissertation I propose a learning algorithm that attends to pairs of overt forms that differ in exactly one morpheme. These pairs can exhibit less ambiguity than the isolated overt forms, while still providing a reduced search space.
The algorithm first assigns underlying values to occurrences of features whose surface realization never alternates; the other underlying features are left initially unset (Tesar et al., 2003). Pairs of overt forms that differ in one morpheme are then constructed. The algorithm then considers the possible values of unset features for each pair, processing pairs with the fewest unset features first. It uses inconsistency detection (Tesar, 1997) to test sets of values of unset features for viability. A set of values for the unset features is viable if it produces the correct overt forms under some ranking. Those feature values which are common across all viable solutions are then set. In the process of testing for inconsistency for each set of values of unset features a set of winner-loser pairs is generated. The learner determines the ranking restrictions jointly entailed by these sets of winner-loser pairs. These ranking restrictions are then maintained while processing all further contrast pairs. After all pairs have been processed, any still unset feature values are assigned default values. The general success of the algorithm depends upon these features being fully predictable in the output. A ranking is then obtained from this lexicon using Biased Constraint Demotion (Prince and Tesar, 2004).
Fixing all non-alternating features reduces the effective lexical search space. The algorithm further reduces the lexical search space by breaking up the search into tractable local pair searches. Extracting shared ranking information from winner-loser pairs generated from inconsistency detection restricts which featural combinations for future contrast pairs will be viable providing information that is otherwise unavailable to the learner.Ph.D.Includes bibliographical references (p. 185-187)
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