176,294 research outputs found
Magmatism associated with Gondwanaland rifting and Neo-Tethyan oceanic basin development: evidence from the Mamonia Complex, SW Cyprus
No full textChan An Ancient Maya Farming Community
No full textThe farming community of Chan thrived for over twenty centuries, surpassing the longevity of many larger Maya urban centers. Between 800 BC and 1200 AD it was a major food production center, and this collection of essays reveals the important role played by Maya farmers in the development of ancient Maya society. Chan offers a synthesis of compelling and groundbreaking discoveries gathered over ten years of research at this one archaeological site in Belize. The contributors develop three central themes, which structure the book. They examine how sustainable farming practices maintained the surrounding forest, allowing the community to exist for two millennia. They trace the origins of elite Maya state religion to the complex religious belief system developed in small communities such as Chan. Finally, they describe how the group-focused political strategies employed by local leaders differed from the highly hierarchical strategies of the Classic Maya kings in their large cities. In breadth, methodology, and findings, this volume scales new heights in the study of Maya society and culture.Cover -- Title -- Copyright -- Contents -- List of Figures -- List of Tables -- Foreword -- Acknowledgments -- 1. Introducing the Chan Site: Farmers in Complex Societies -- Part 1. Time, Space, and Landscapes -- 2. A Changing Cultural Landscape: Settlement Survey and GIS at Chan -- 3. Ceramics and Chronology at Chan -- 4. Agricultural Practices at Chan: Farming and Political Economy in an Ancient Maya Community -- 5. Agroforestry and Agricultural Production of the Ancient Maya at Chan -- Part 2. Life in a Farming Community Center -- 6. Ritual in a Farming Community -- 7. Nonroyal Governance at Chan's Community Center -- 8. "Empty" Spaces and Public Places: A Microscopic View of Chan's Late Classic West Plaza -- Part 3. Diversity across the Chan Community -- 9. Recognizing Difference in Small-Scale Settings: An Examination of Social Identity Formation at the Northeast Group, Chan -- 10. Organization of Chert Tool Economy during the Late and Terminal Classic Periods at Chan: Preliminary Thoughts Based upon Debitage Analyses -- 11. Limestone Quarrying and Household Organization at Chan -- Part 4. Bodies, Material Culture, and Meaning -- 12. The Chan Community: A Bioarchaeological Perspective -- 13. Creating Community with Shell -- 14. Obsidian Acquisition, Trade, and Regional Interaction at Chan -- 15. Contextualizing Ritual Behavior: Caches, Burials, and Problematical Deposits from Chan's Community Center -- Part 5. Conclusion -- 16. Learning from an Ancient Maya Farming Community -- References -- List of Contributors -- Index -- A -- B -- C -- D -- E -- F -- G -- H -- I -- J -- K -- L -- M -- N -- O -- P -- Q -- R -- S -- T -- V -- W -- X -- YThe farming community of Chan thrived for over twenty centuries, surpassing the longevity of many larger Maya urban centers. Between 800 BC and 1200 AD it was a major food production center, and this collection of essays reveals the important role played by Maya farmers in the development of ancient Maya society. Chan offers a synthesis of compelling and groundbreaking discoveries gathered over ten years of research at this one archaeological site in Belize. The contributors develop three central themes, which structure the book. They examine how sustainable farming practices maintained the surrounding forest, allowing the community to exist for two millennia. They trace the origins of elite Maya state religion to the complex religious belief system developed in small communities such as Chan. Finally, they describe how the group-focused political strategies employed by local leaders differed from the highly hierarchical strategies of the Classic Maya kings in their large cities. In breadth, methodology, and findings, this volume scales new heights in the study of Maya society and culture.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
Atroposelective Chan-Evans-Lam Amination
No full textThe synthetic control of atropoisomerism along C─N bonds is a major challenge, and methods that allow C─N atroposelective bond formation are rare. This is a problem because each atropoisomer can feature starkly differentiated biological properties. Yet, among the three most practical and applicable classical amination methods available: 1) the Cu-catalyzed Ullmann-Goldberg reaction, 2) the Pd-catalyzed Buchwald-Hartwig reaction, and 3) the Cu-catalyzed Chan-Evans-Lam reaction, none has truly been rendered atroposelective at the newly formed C─N bond. The first ever Chan-Evans-Lam atroposelective amination is herein described with a simple copper catalyst and new PyrOx chiral ligand. This method constitutes a change of paradigm in the field
A paixão segundo G.H.: author and reader in the difficult joy of otherness
Full text linkThis article proposes a reading of Clarice Lispector’s novel A paixão segundo G.H., published in 1964. This article is about a reading on otherness, established by the author-reader relationship and the combination of literature and philosophical thought. For this purpose, we shall seek the contributions from Jean-Paul Sartre’s existentialist theory, through his work O ser e o nada: ensaio de ontologia fenomenológica (2015b), and the ideas about the question of the author and the reader as participating literary elements of the process of writing the literary text, which were developed by Antoine Compagnon in his book O demônio da teoria(2010). This work is the result of a Master’s research in Comparative LiteratureEste artigo propõe uma leitura do romance A paixão segundo G.H., de Clarice Lispector, publicado em 1964. Trata-se, aqui, de uma leitura sobre alteridade, estabelecida pela relação autor-leitor e pela junção da literatura com o pensamento filosófico. Para tanto, buscaremos aporte na teoria existencialista de Jean-Paul Sartre, com sua obra O ser e o nada – ensa io de ontologia fenomenológica (2015b), e nas ideias sobre a questão do autor e do leitor, como elementos literários participantes do processo de escritura do texto literário, desenvolvidas por Antoine Compagnon em O demônio da teoria (2010). Este trabalho é resultado de uma pesquisa desenvolvida no Mestrado em Literatura Comparada.PALAVRAS-CHAVE: Clarice Lispector. A paixão segundo G.H. Alteridade. Autor. Leitor. ABSTRACT: This article proposes a reading of Clarice Lispector’s novel A paixão segundo G.H., published in 1964. This article is about a reading on otherness, established by the author-reader relationship and the combination of literature and philosophical thought. For this purpose, we shall seek the contributions from Jean-Paul Sartre’s existentialist theory, through his work O ser e o nada: ensaio de ontologia fenomenológica (2015b), and the ideas about the question of the author and the reader as participating literary elements of the process of writing the literary text, which were developed by Antoine Compagnon in his book O demônio da teoria(2010). This work is the result of a Master’s research in Comparative Literature.KEYWORDS: Clarice Lispector. A paixão segundo G.H. Otherness. Author. Reader.1 Este trabalho é resultado de uma pesquisa de mestrado que teve financiamento da CAPES - Coordenação de aperfeiçoamento de Pessoal de Nível Superior.* Mestre em Estudos da Linguagem pela Universidade Federal do Rio Grande do Norte.** Professor Adjunto do Departamento de Línguas e Literaturas Estrangeiras Modernas e docente permanente do Programa de Pós-graduação em Estudos da Linguagem da Universidade Federal do Rio Grande do Norte
Probing the basement of southern Tibet : evidence from crustal xenoliths entrained in a Miocene ultrapotassic dyke
Full text linkA variety of felsic and mafic granulites and ultramafic rocks occur as xenoliths within a 12.7 Ma ultrapotassic dyke intruding Xigaze flysch immediately to the north of the Yarlung-Tsangpo suture zone in southern Tibet. Garnet-clinopyroxene-plagioclase-quartz thermobarometry on mafic granulite xenoliths gives temperatures of 1130-1330 °C and pressures between 22 and 26 kbar indicating equilibration in the high-pressure and ultrahigh-temperature granulite field and defining a geotherm of c. 16 °C km-1. Ultramafic xenoliths consist mainly of hornblende and biotite, probably of restitic crustal rather than mantle origin, and attained peak metamorphic conditions of 920-1130 °C and 17-24 kbar, whereas felsic granulites equilibrated at 870-900 °C at an inferred pressure of 17 kbar. In situ U-(Th)-Pb laser ablation inductively coupled plasma mass spectrometry dating of zircons shows that protoliths may include Proterozoic basement rocks, Late Cretaceous calc-alkaline tonalites of the Gangdese batholith root and/or remnants of a Neo-Tethyan oceanic arc. Certain zircons from a felsic granulite and an ultramafic xenolith have mean 206Pb/238U ages of 16.8 ± 0.9 Ma and 15.6 ± 0.6 Ma, respectively, and monazites from a micaceous xenolith yielded a mean 208Pb/232Th age of 14.4 ± 0.4 Ma. These results show that the southern Tibet basement reached a thickness of c. 80 km by 17-14 Ma at the latest and has remained unchanged until the present day. © 2009 Geological Society of London
Dynamic Geometric Connectivity in the Plane with Constant Query Time
Full text linkWe present the first fully dynamic connectivity data structures for geometric intersection graphs achieving constant query time and sublinear amortized update time for many classes of geometric objects in 2D . Our data structures can answer connectivity queries between two objects, as well as "global" connectivity queries (e.g., deciding whether the entire graph is connected). Previously, the data structure by Afshani and Chan (ESA'06) achieved such bounds only in the special case of axis-aligned line segments or rectangles but did not work for arbitrary line segments or disks, whereas the data structures by Chan, Pătraşcu, and Roditty (FOCS'08) worked for more general classes of geometric objects but required n^{Ω(1)} query time and could not handle global connectivity queries.
Specifically, we obtain new data structures with O(1) query time and amortized update time near n^{4/5}, n^{7/8}, and n^{20/21} for axis-aligned line segments, disks, and arbitrary line segments respectively. Besides greatly reducing the query time, our data structures also improve the previous update times for axis-aligned line segments by Afshani and Chan (from near n^{10/11} to n^{4/5}) and for disks by Chan, Pătraşcu, and Roditty (from near n^{20/21} to n^{7/8})
Harry Chan
No full textHarry Chan, Member of the Legislative Council for Fannie Bay, taking oath of office as first elected president of Legislative Council - ninth Council.Gleeson, N.Date:1965-1
Dynamic Geometric Data Structures via Shallow Cuttings
Full text linkWe present new results on a number of fundamental problems about dynamic geometric data structures:
1) We describe the first fully dynamic data structures with sublinear amortized update time for maintaining (i) the number of vertices or the volume of the convex hull of a 3D point set, (ii) the largest empty circle for a 2D point set, (iii) the Hausdorff distance between two 2D point sets, (iv) the discrete 1-center of a 2D point set, (v) the number of maximal (i.e., skyline) points in a 3D point set. The update times are near n^{11/12} for (i) and (ii), n^{7/8} for (iii) and (iv), and n^{2/3} for (v). Previously, sublinear bounds were known only for restricted "semi-online" settings [Chan, SODA 2002].
2) We slightly improve previous fully dynamic data structures for answering extreme point queries for the convex hull of a 3D point set and nearest neighbor search for a 2D point set. The query time is O(log^2n), and the amortized update time is O(log^4n) instead of O(log^5n) [Chan, SODA 2006; Kaplan et al., SODA 2017].
3) We also improve previous fully dynamic data structures for maintaining the bichromatic closest pair between two 2D point sets and the diameter of a 2D point set. The amortized update time is O(log^4n) instead of O(log^7n) [Eppstein 1995; Chan, SODA 2006; Kaplan et al., SODA 2017]
Heng Fook (Harry) Chan
No full textPortrait of Harry Chan, Legislative Council member for Fannie Bay, first elected President of Council - in library of Legislative Council.Gleeson, N.Date:196
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