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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

A test of factors affecting the foraging success of scarlet ibis

Unknown Date (has links)
Wading bird foraging success is influenced by many different factors. From January to March 2008, I conducted a small-scale experiment with three captive Scarlet Ibis (Eudocimus ruber) at the Palm Beach Zoo, in West Palm Beach, Florida. Prey density and the presence of conspecifics were manipulated to test for a response by ibis in terms of prey capture rate. Mixed model analysis, when one prey type was available, showed that capture rate increased significantly with prey density and decreased with the presence of conspecifics. When two prey types were available, prey density and the presence of conspecifics had no effect on the capture rates of either prey type. Selectivity analysis revealed that ibis always selected for crayfish in mixed treatments. I hypothesize that the number of prey types available in a treatment played an important role in determining how fish density and the presence of conspecifics affected ibis foraging success. / by Rebecca A. Stanek. / Thesis (M.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.
32

An investigation on the formation and occurrence of spiral grain and compression wood in radiata pine (Pinus radiata D. Don.)

Thomas, Jimmy January 2014 (has links)
Radiata pine (Pinus radiata) is the most important plantation tree in New Zealand forestry, and factors that reduce the quality of wood cause significant economic loss. Two of the most important of these issues are compression wood and spiral grain. Compression wood is a type of reaction wood, formed when a tree moves away from the vertical, and is characterised by biochemical and structural changes within the wood that reduce its quality and value. Spiral grain, however, is the alignment of the wood grain in a helix around the tree’s axis and away from the vertical. Again, this reduces the structural qualities of the wood and thus its value. Spiral grain and compression wood are notorious for their deleterious effect on the quality of wood produced and are very important for the forest industry due to the huge economic loss they cause. The demand for reliable tools to evaluate these wood quality issues in clonal planting material at an early stage, within 3 years of germination rather than at 8 to 15 years as in current practise, is of ever increasing importance from plant breeders and other industry stake holders. Therefore this research was undertaken with an overall aim to develop quick, easy and reproducible techniques to evaluate young radiata pine clones (up to 3 years old) based on compression wood content and presence of spiral grain. This is important because a shortened breeding cycle could provide significant economic benefits to the forest industry. The incidence of these commercially important wood quality parameters has been studied in this thesis in research conducted on young trees (1 to 3 years old). The research described in this thesis used a variety of different imaging approaches to investigate wood structure, including polarised light and confocal microscopy, and X-ray tomography and circular polarised light scanning. The images achieved have been analysed using a range of different software, including Photoshop, ImageJ and Matlab bringing a quantification approach to the imaging. Compression wood was quantified in young clonal material using images collected with a commercial document scanner, and processed using image analysis tools available in Photoshop. An easy, reliable and robust, automatic image analysis protocol was successfully developed and tested for the detection and quantification of compression wood in these young trees. This new technique to detect and quantify compression wood was based on the thresholding of the blue channel of the scanned RGB image as this was demonstrated to contain the greatest image contrast. Development of this new technique may reduce the waiting time for screening clonal planting materials based on compression wood content. To understand the organisation of the grain at a cellular level within these young trees, confocal microscopy techniques were utilised. The cell wall characteristics and fluorescence properties of compression wood in comparison with normal wood were investigated using a new cellulose specific dye, pontamine fast scarlet 4B. Staining protocols for this dye for confocal microscopy were optimised, and the potential of measuring the microfibril angle of the S1 and S3 layers of the pontamine treated opposite wood was demonstrated through either direct observations of these layers, or through the property of bifluorescence where the dye is excited only when aligned parallel to the polarisation of the incident light. Despite extensive work with confocal microscopy, this technique proved to be unsuitable for investigations of spiral grain because although it provided cellular detail, imaging was limited to the surface layers of sections, and the area over which observations were required was prohibitive. Instead of confocal microscopy, the incidence of spiral grain in young stems was investigated in two completely new ways. Resin canals, which are formed from the same cambial initials as the tracheids and which align with the grain, were used as a proxy to demonstrate the grain changes. A novel technique, using circular polarised light and a professional flatbed scanner, was developed to image whole serial transverse sections of the young stems to detect the resin canals. Using ImageJ, the number and location of resin canals was measured on vertical controls, and trees that had been rocked and leaned. The number and frequency of resin canals were less in tilted trees, especially in compression wood, compared to the higher number of canals formed in the rocked trees. More importantly, a combination of serial sectioning and this approach allowed a 3-dimensional view of the orientation of resin canals inside a stem to be generated with ImageJ, and the angles of these canals could be measured using Matlab. The resin canals were oriented with a left-handed spiralling near the stem surface whereas the canals near to the pith were nearly straight, consistent with previous observations of the development of spiral grain in radiata pine. However, it was observed that while vertical trees had a symmetric pattern of grain and grain changes around the stem, this was not the case in tilted trees. In these, the opposite wood often had severe spiral grain visible through formation of twist whereas the compression wood formed on the lower side had bending. Consistent with this, grain associated with compression wood was significantly straighter than in opposite wood. This hitherto unknown link between the incidence of compression wood and spiral grain was investigated and explained on the basis of the characteristics of resin canals in these types of wood. X-ray micro-tomography was also used to investigate resin canals in the stubs from which serial sections were collected. The 3D reconstructions of the resin canals showed exactly the same patterns as observed by polarised light scanning.
33

Problemas taxonômicos da família Threskiornithidae: filogenia molecular e o caso de Eudocimus

Malaver, Jorge Luis Ramirez 01 March 2011 (has links)
Made available in DSpace on 2016-06-02T20:21:26Z (GMT). No. of bitstreams: 1 3664.pdf: 2255481 bytes, checksum: 8606405322631d7b23133954708544a6 (MD5) Previous issue date: 2011-03-01 / Financiadora de Estudos e Projetos / The family Threskiornithidae includes 13 genera and 32 species, but the relationships among genera, species or subspecies have been little studied. This family is traditionally divided into two subfamilies: Plataleinae and Threskiornithinae. One of the more interesting taxonomical questions within this group is the case of the species Eudocimus ruber and Eudocimus albus. They are usually considered as separate species, but they show similar behavior and there are also records of hybridization in nature. This study aims to reconstruct the phylogenetic relationships within the family Threskiornithidae as well as assess the level of genetic differentiation between Eudocimus albus and E. rubber, using mitochondrial and nuclear gene sequences. DNA was extracted from blood and tissue samples from 13 species of Threskiornithidae (seven genera) and two outgroups. For the Eudocimus study were extracted 10 individuals of each species. We sequenced the 16S rRNA and the intron 7 of β- Fibrinogen for all species. For Eudocimus Cytochrome B, Cytochrome Oxidase I, intron 11 of Glyceraldehyde-3-Phosphate Desidrogenase, intron 4 of the Myelin Proteolipid Protein and intron 2 of Myoglobin were also sequenced. Sequences for other five species of the family were obtained from GenBank. Phylogenetic trees were constructed using Neighbor-Joining, Maximum Parsimony, Maximum Likelihood, Bayesian inference and Bayesian inference of species tree. Networks and genetic distances were determined for Eudocimus haplotypes. Several approaches for species delimitation using multilocus data were applied. All analyses strongly supported the family Threskiornithidae (18 species) as a monophyletic group. However, the current classification of two subfamilies was not supported by our data: Plataleinae formed a monophyletic group, but nested within Threskiornithinae (a paraphyletic group). Tests of monophyly rejected the hypothesis of monophyly of Threskiornithinae. The family Threskiornithidae also showed a division into two groups: one with only genera endemic to the American continent (Theristicus and Eudocimus) and another with the remaining species. Within the latter clade, species of genus Plegadis are observed in a basal position, while subfamily Plataleinae was grouped with the remaining species. This pattern of species distribution suggests an initial Gondwana division and subsequent colonization by species from the Old to the New World. The divergence within the family was estimated at 35-40 million years, which is before the separation between America and Antarctica. Mitochondrial genetic analysis showed Eudocimus species as two different lineages. Multilocus analysis based on nuclear genes revealed a strong signal of speciation despite the polyphyly found in three of the four markers. / A família Threskiornithidae inclui 13 gêneros e 32 espécies e suas relações interespecíficas, assim como as designações dos gêneros, espécies ou subespécies foram pouco estudadas. A família tem sido dividida em duas subfamílias: Plataleinae e Threskiornithinae. O caso de Eudocimus ruber e Eudocimus albus é uma das questões interessantes da taxonomia do grupo, pois têm sido consideradas como espécies, mas mostram similaridades no comportamento e há registros de hibridização na natureza. Os objetivos do presente estudo foram reconstruir as relações filogenéticas dentro da família Threskiornithidae e avaliar o nível de diferenciação genética entre Eudocimus albus e E. ruber, baseando-se nos dados de sequências de genes mitocondriais e nucleares. DNA foi extraído de amostras de sangue e de tecidos de 13 espécies de Threskiornithidae, representantes de sete gêneros da família e de dois grupos externos. Para o estudo do caso de Eudocimus foram analisadas amostras de 10 indivíduos de cada espécie. Foram sequenciados os genes 16S rRNA e o íntron 7 do β-fibrinogênio para todas as espécies. Nos indivíduos de Eudocimus foram sequenciados também os genes Citocromo B, Citocromo Oxidase I, o íntron 11 da Gliceraldeído-3-Fosfato Desidrogenase, o íntron 4 da Proteína Proteolipídica da Mielina e o íntron 2 da Mioglobina. Sequências para outras cinco espécies da família foram obtidas do GenBank. Árvores filogenéticas foram construídas pelos métodos de inferência de Neighbor-Joining, Máxima Parcimônia, Máxima Verossimilhança, Análise Bayesiana e Estimativa Bayesiana de árvore de espécies. Redes de haplótipos e distâncias genéticas foram determinadas para as sequências de Eudocimus. Diversas abordagens de delimitação de espécies usando informação multilocus foram realizadas. A família Threskiornithidae com 18 espécies se apresentou como grupo monofilético fortemente sustentado em todas as análises. A classificação atual das duas subfamílias não foi corroborada: Plataleinae se apresentou como grupo monofilético, mas agrupada dentro dos Threskiornithinae, sendo este último um grupo parafilético. Os testes de monofilia rejeitaram a hipótese de Threskiornithinae ser um grupo monofilético. A família Threskiornithidae pode ser dividida em dois grupos: o primeiro agrupando somente gêneros endêmicos do continente americano (Theristicus e Eudocimus) e o outro com as demais espécies. Dentro deste ultimo clado, observa-se em posição basal as espécies do gênero Plegadis e a subfamília Plataleinae agrupada com o restante das espécies. Este padrão de distribuição de espécies concorda com uma divisão inicial Gondwânica e uma posterior colonização por espécies do velho ao novo mundo. A divergência da família foi estimada em 35 40 milhões de anos, data anterior à separação do continente Americano da Antártica. As análises genéticas mitocondriais mostraram as espécies de Eudocimus como duas linhagens diferentes. Nas análises multilocus baseadas nos genes nucleares foi possível recuperar um forte sinal de especiação apesar da polifilia encontrada em três dos quatro marcadores.
34

Counter-monumentalism in the Search for American Identity in Hawthorne's The Scarlet Letter & The Marble Faun

Mise, Carmen 30 June 2015 (has links)
This study examines the crisis of identity the United States was experiencing in the nineteenth-century through two of the major literary works of Nathaniel Hawthorne, The Scarlet Letter and The Marble Faun. Hawthorne, who lived through this crucial and important developmental period, was concerned as to what this identity would be, how the United States would shape and define itself, and what its future would be if this identity was malformed. In addition, this study will look at counter-monuments as argued by James E. Young in his essay “The Counter-Monument: Memory against Itself in Germany Today” to expand on these issues of identity. If according to Young, the ideal goal of the counter-monument is “not to remain fixed but to change,” one can conclude that Hawthorne understood that national identity must be fluid; otherwise, the nation would crumble under the pressure and force of change.
35

Hawthorne's Use of the Supernatural in Three Romances

Reeves, Eunice January 1949 (has links)
This thesis is a study of three of Hawthorne's long romances, The Scarlet Letter, The House of the Seven Gables, and The Marble Faun, with particular attention to his use of phenomena having the appearance of the supernatural as a means of exemplifying the theme of his romances.
36

Optical Response of Plasmas from Moderate Intensity to the Relativistic Regime

Zingale, Anthony January 2021 (has links)
No description available.
37

Att möta sig själv och att bli den Andre : En intersektionell och postkolonial analys av Marissa Meyers Cinder och Scarlet / Encountering Oneself and Become the Other : An Intersectional and Postcolonial analysis of Marissa Meyer’s Cinder and Scarlet

Olsson, Mikaela January 2021 (has links)
This study examines power structures and oppression in the first two novels of the Lunar Chronicles by Marissa Meyer. Postcolonial theory and concepts as the Other/the other, and mimicry supplemented with an intersectional perspective are applied in the study. The study investigates how the protagonist, Cinder, is treated as a cyborg in a human world, and as a Lunar on Earth. Furthermore, it focuses on what happens when the oppressed becomes the oppressor and gains power. I conclude that the humans in Meyer’s sequel treat cyborgs in a similar way as the colonizer has treated the colonized through history. Cyborgs are suppressed due to fear from humans who neither understand cyborgs, nor have any interest to learn about them. The humans have a preconceived idea about what and who the cyborgs are and in correlation to the colonizer, the humans see no point in changing that view. Therefore, humans take the role as the Other while pushing cyborgs to become the other. In a similar way, Lunars become the Other due to their Lunar gift, which creates a power imbalance that they use to suppress people on Earth. When Cinder accesses her Lunar gift, she transforms from being the oppressed into the oppressor, and she must face the consequences of possessing such power which results in someone’s death. She realizes then that she would rather be the oppressed and be hurt herself than to be the oppressor and hurt others.
38

Salem Belles, Succubi, and The Scarlet Letter: Transatlantic Witchcraft and Gothic Erotic Affect

Cutler, Sylvia 01 August 2019 (has links)
In order to reconcile the absence of sexually deviant witch figures (succubae, demonic women, etc.) within the formation of American national literature in the nineteenth century with the fantastic elements found in European variations on the gothic, my thesis aims to demonstrate transatlantic variants of erotic signifiers attached to witch figures in nineteenth-century gothic fiction and mediums across national traditions. I will begin by tracing the transatlantic and historical impact of Heinrich Kramer and Jacob Sprenger’s Malleus Maleficarum—an early modern handbook of sorts used widely in witchcraft inquisitions—on Early American witch trials, specifically where its influence deviates from a sexualized conception of the witch and where a different prosopography of the historical witch emerges. Next, I will assess a short sample of nineteenth-century American pulp fiction to demonstrate the historical impact of America’s erotically decoded witch type on fictionalized versions or caricatures of the witch. In doing so I hope to create a reading that informs a more transatlantically complex representation of The Scarlet Letter. Finally, in order to underscore the significance of these national and historical departures of The Scarlet Letter as a gothic novel, I will contrast Hawthorne’s novel with a selective reading of nineteenth-century gothic texts from England and France that employ the witch or demonic feminine motif in an erotically codified and fantastic setting, namely using Old World magic and history that draws from French and English traditions.To demonstrate the significance of erotically coded witches in the British tradition, I will briefly examine Samuel Taylor Coleridge’s “Christabel” as a gothic text that relies heavily on the erotic affect encoded in the figure of Geraldine. I will also touch on Prosper Mérimée’s “La Vénus d’Ille” and Théophile Gautier’s “La Morte Amoreuse,” two remarkable short stories that highlight the sublime terror of sexually deviant, occult female figures. Through such a collection of readings of witches and erotic, occult women I hope to amplify a more latent theme underlying The Scarlet Letter and America’s conflicted relationship with the gothic tradition: namely its crucial lack of erotic enchantment as a channel for the experience of gothic affect, the fantastic, and even sublime terror.
39

The Development of Self in Hawthorne's The Scarlet Letter, Chopin's The Awakening, and Atwood's The Handmaid's Tale.

Parkinson, Lynn Jill January 1988 (has links)
<p>This study is an examination of the developing self-consciousness of three female protagonists in three different novels. Chapter One is a discussion of the detrimental social factors that hinder the complete selfdevelopment of Hester Prynne in the seventeenth-century New England environment of Hawthorne's The Scarlet Letter. Chapter Two investigates the emerging consciousness of self of Edna Pontellier and her subsequent failure to achieve an autonomy that permits her to integrate into the confining, social climate of Chopin's nineteenth-century Creole environment in The Awakening. Chapter three is the examination of the repressive forces in the futuristic society of Gilead that serve as a barrier to the development of a unified self for Offred in Atwood's The Handmaid's Tale. In all three chapters of the thesis, I argue that each female protagonist's struggle to successfully assert the self, and to extend the self toward genuine relationships with others, is not actualized. This study attempts to show the precarious hold of the self that the female protagonist demonstrates in each of these three works of fiction. Throughout the body of the text, an abbreviated form iii iv will be used for the three primary novels examined. The reference consists of the underlined initials of the title of the novel followed by the page number, all contained within parentheses. The abbreviations are as follows: TSL for Hawthorne's The Scarlet Letter, TA for Chopin's The Awakening, and THT for Atwood's The Handmaid's Tale.</p> / Master of English
40

Wees Gonna Tell It Like We Know It Tuh Be: Coded Language in the Works of Julia Peterkin and Gloria Naylor

Hills, Crystal Margie 21 August 2008 (has links)
This study employs African American literary criticism and critical discourse analysis to evaluate Julia Peterkin's Scarlet Sister Mary (1928) and Gloria Naylor's Mama Day (1988). These women write stories of African American life on the Sea Islands through different prisms that evoke cultural memory within and outside the texts. Peterkin, a white Southerner, writes as an "onlooker" and “pioneer” of fictional Gullah culture; Naylor, a black Northerner by birth, writes as an "outsider" to Gullah culture, although a veteran of African American Southern heritage. The authors' hybridity produce different literary voices. A close examination of their discourse conveys a coded language pertinent to understanding the historical, social, and political conditions portrayed through their texts. This study will examine their discourse to prove that Julia Peterkin’s, Scarlet Sister Mary, takes ownership over the Gullah experience rendering stereotypical characterizations promoting hegemony; while Gloria Naylor's, Mama Day, resurrects Peterkin’s view rendering multi-dimensional characterizations that legitimize the authenticity of Gullah culture and aid in its preservation.

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