6 resultados para NMR symbols and terms

em Digital Commons at Florida International University


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This longitudinal study provides a detailed description of the transition in the Bahamas from British colony to independent country. It analyzes the ongoing process of legitimation and delegitimation of Bahamian political parties and of the transfer of authority from the white minority to the black majority. It is a story of social and political struggles that take place within the quarter century following World War II. These struggles are analyzed within a theoretical framework which focuses on the meaning of symbols used to support claims to authority, and/or which function to delegitimize alternative claims. Specifically, this study looks at the delegitimization of the institutions of colonialism and the concurrent profession of symbols to support both independence and a fully enfranchised democracy in the Bahamas. ^ The research methodology includes an extensive analysis of official British colonial documents, private governmental dispatches, and contemporaneous newspaper articles. The sources were primarily the Public Records Office of Great Britain; the Archives of the Bahamas; and the Institute for Social and Economic Research, University of the West Indies. Secondary literature on civil rights, political science, religion, Black Nationalism, corruption, social theory, and popular culture was studied. Two hundred days of participant observation, spread over seven years of study, resulted in notes from which information was gleaned. During that time, seventeen open-ended interviews with a cross section of Bahamians (male and female, black and white) who lived through this period were recorded, information from which was also incorporated. ^ A detailed description of the socio-historical process, and an analysis of data, demonstrates how the black majority's desire for political representation, and future independence, pressured Great Britain to come into line with the desires of the majority of Bahamians. The symbolic universe that had historically divided white from black now urged dramatic social and political change. ^ The documents and testimonials studied demonstrate how symbols and symbolic events supported and/or undercut the claims to legitimacy proffered by different groups in the Bahamas in their respective attempts to solidify their social and political position within the society. ^

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We conducted a series of experiments whereby dissolved organic matter (DOM) was leached from various wetland and estuarine plants, namely sawgrass (Cladium jamaicense), spikerush (Eleocharis cellulosa), red mangrove (Rhizophora mangle), cattail (Typha domingensis), periphyton (dry and wet mat), and a seagrass (turtle grass; Thalassia testudinum). All are abundant in the Florida Coastal Everglades (FCE) except for cattail, but this species has a potential to proliferate in this environment. Senescent plant samples were immersed into ultrapure water with and without addition of 0.1% NaN3 (w/ and w/o NaN3, respectively) for 36 days. We replaced the water every 3 days. The amount of dissolved organic carbon (DOC), sugars, and phenols in the leachates were analyzed. The contribution of plant leachates to the ultrafiltered high molecular weight fraction of DOM (>1 kDa; UDOM) in natural waters in the FCE was also investigated. UDOM in plant leachates was obtained by tangential flow ultrafiltration and its carbon and phenolic compound compositions were analyzed using solid state 13C cross-polarization magic angle spinning nuclear magnetic resonance (13C CPMAS NMR) spectroscopy and thermochemolysis in the presence of tetramethylammonium hydroxide (TMAH thermochemolysis), respectively. The maximum yield of DOC leached from plants over the 36-day incubations ranged from 13.0 to 55.2 g C kg−1 dry weight. This amount was lower in w/o NaN3 treatments (more DOC was consumed by microbes than produced) except for periphyton. During the first 2 weeks of the 5 week incubation period, 60–85% of the total amount of DOC was leached, and exponential decay models fit the leaching rates except for periphyton w/o NaN3. Leached DOC (w/ NaN3) contained different concentrations of sugars and phenols depending on the plant types (1.09–7.22 and 0.38–12.4 g C kg−1 dry weight, respectively), and those biomolecules comprised 8–34% and 4–28% of the total DOC, respectively. This result shows that polyphenols that readily leach from senescent plants can be an important source of chromophoric DOM (CDOM) in wetland environments. The O-alkyl C was found to be the major C form (55±9%) of UDOM in plant leachates as determined by 13C CPMAS NMR. The relative abundance of alkyl C and carbonyl C was consistently lower in plant-leached UDOM than that in natural water UDOM in the FCE, which suggests that these constituents increase in relative abundance during diagenetic processing. TMAH thermochemolysis analysis revealed that the phenolic composition was different among the UDOM leached from different plants, and was expected to serve as a source indicator of UDOM in natural water. Polyphenols are, however, very reactive and photosensitive in aquatic environments, and thus may loose their plant-specific molecular characteristics shortly. Our study suggests that variations in vegetative cover across a wetland landscape will affect the quantity and quality of DOM leached into the water, and such differences in DOM characteristics may affect other biogeochemical processes.

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The purpose of this dissertation was to analyze the works of Federico García Lorca within the mystic context that dominates their very genesis. The problematic definition of mysticism was explored lest it be confused with traditional mysticism, which implies union with the divine. The historiography of literature speaks of the Mystic Genre, yet it does not address the mystic mode of artistic creation due to its inability to adhere to rational measure. This mode of conception was explored through Lorca's poetic discourse: ‘Lorquian mysticism’ is the result of the poet's cultivation of an innate spiritual potential enhanced by external influences and technical mastery. ^ There is visible influence of Fray Luis of León in Lorca's early Libro de poemas and El maleficio de la mariposa, as well as of Saint John of the Cross in the later Diván del Tamarit, Sonetos de amor and Yerma. However, definitive echoes of poets from the Sufi and other Eastern mystic traditions were also illustrated in these late works. A persistent longing to elide the physical condition, the greatest obstacle of the transcendental quest, is the essence of Lorca's poetic voice. ^ The object of this analysis was Lorca's language, which reaches levels removed from conventional thought. His dazzling metaphors and his particular use of symbols and of paradox compare equitably with those of great mystic poets. Like them, Lorca was faced with the same limitations of language to describe an ineffable experience; he embraced what Octavio Paz describes as ‘sacred language’: there is a linguistic frugality as well as an ambiguity in Lorca's poetic art that result from his realization of supercognitive states. Yet such an interpretation is rejected by the rationalist approach, invoking the age-old debate between faith and reason and signaling the application of psychoanalytical theory. This limited approach was disputed on the basis of reader-response theory. Lorca was truly an eclectic and a modification of the conventional reader's preestablished horizon of expectations is essential in order to seal the gaps in his late works. This innovative perspective placed Lorca within the framework of a new mysticism in the modern world. ^

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In this study, the molecular composition of dissolved organic matter (DOM), collected from wetlands of the Southern Everglades, was examined using a variety of analytical techniques in order to characterize its sources and transformation in the environment. The methods applied for the characterization of DOM included fluorescence spectroscopy, solid state 13C CPMAS NMR spectroscopy, and pyrolysis-GC/MS. The relative abundance of protein-like components and carbohydrates increased from the canal site to more remote freshwater marsh sites suggesting that significant amounts of non-humic DOM are autochthonously produced within the freshwater marshes, and are not exclusively introduced through canal inputs. Such in situ DOM production is important when considering how DOM from canals is processed and transported to downstream estuaries of Florida Bay.

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The Everglades Online Thesaurus is a structured vocabulary of concepts and terms relating to the south Florida environment. Designed as an information management tool for both researchers and metadata creators, the Thesaurus is intended to improve information retrieval across the many disparate information systems, databases, and web sites that provide Everglades-related information. The vocabulary provided by the Everglades Online Thesaurus expresses each relevant concept using a single ‘preferred term’, whereas in natural language many terms may exist to express that same concept. In this way, the Thesaurus offers the possibility of standardizing the terminology used to describe Everglades-related information — an important factor in predictable and successful resource discovery.

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Chromatographic analyses of crude leaf extracts of Flaveria linearis L. revealed the presence of four acetylenic monothiophenes. Three of these metabolites were purified and structurally characterized by UV, NMR, IR, and GC-MS. Germination, growth, and survival/mortality studies with and without UVA, the activating wavelengths of these metabolites, were conducted with the crude leaf extracts and the purified compounds (taken individually and combined) against selected crop species (lettuce, radish, and carrot). Results suggest that acetylenic metabolites are phytotoxic against lettuce, carrot, and radish, but with variability in response among species. These variations in sensitivity and the allelopathic potential of F. linearis is discussed.