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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.
1141

Repensando a interface sintaxe-fonologia a partir do axioma de correspondencia linear

Guimarães Miranda, Maximiliano 22 June 1998 (has links)
Orientador: Charlotte Galves / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-07-23T23:26:49Z (GMT). No. of bitstreams: 1 GuimaraesMiranda_Maximiliano_M.pdf: 11311967 bytes, checksum: 496d585bffd2aec679a254409cc559b7 (MD5) Previous issue date: 1998 / Resumo: Esta dissertação trata da interface sintaxe-fonologia. O quadro teórico é definido no âmbito de duas teorias complementares: o Programa Minimalista (Chomsk.ry 1993, 1994, 1995; Kayne 1994) & a Teoria da Hierarquia Prosódica (Selkirk 1984, 1986; Nespor & Vogel 1986; Inkelas & Zec 1990). Faço aqui as seguintes propostas: (i) Ao se reinterpretar o passos de base & o passo recursivo da versão pós-kayneana do LCA como sendo dois algoritmos distintos de mapeamento do componente fonológico, é possivel capturar algumas propriedades básicas da estrutura prosódica; (ii) Os procedimentos de mapeamento da computação fonológica são aplicados na seguinte ordem: linearização, morfologia, hierarquização prosódica e regras fonológicas stricto sensu, (iii) Depois da linearização, as informações sintáticas deixam definitivamente de estar disponíveis para o componente fonológico. Toda e qualquer operação subseqüente deverá se aplicar com 1;>ase apenas nas informações codificadas nas strings geradas pelo 'LCA fatorado'; (iv) O sistema computacional permite a geração de projeções vácuas através de operações de auto-conexão - para evitar estruturas não-linearizáveis; (v) A geometria da hierarquia prosódica é organizada em camadas, de tal' modo que palavras prosódicas são imediatamente p-dominadas tanto por sintagmas fonológicos como por sintagmas entoacionais, os quais pertencem a duas subierarquias paralelas / Abstract: This dissertation deals with the syntax-phonology interface. The theoretical framework consists of two complementary theories: the Minimalist Program (Chomsky 1993, 1994, 1995; Kayne 1994) & the Theory of Prosodic Hierarchy (Selkirk 1984, 1986; Nespor & Vogel 1986; Inkelas & Zec 1990). Here I make the following claims: (i) By taking the base & the recursive steps of the bare-phrase version of Kayne's LCA to be two distinct mapping algorithms of the PF component, it is possible to account for some core properties of prosodic structure; (ii) The mapping procedures of the phonological computation . are derivationally ordered as follows: linearization, morphology, prosodic phrasing and pure phonological rules; (iii) After linearization takes place, syntactic information is not availabe for the PF component. Any further operations have to proceed solely on the basis of the information encoded in the strings generated by the 'factored LCA'; (iv) The computational system allows the generation of vacuous projections, through self-merge operations, in order to avoid unlinearizeable structures; (v) The geometry of the prosodic .hierarchy is organized in tiers, so that prosodic words are immediately p-dominated both by phonological phrases and by intonational phrases, which belong to two parallel subhierarchies / Mestrado / Mestre em Linguística
1142

Investigação in situ da influência reversível da não-estequiometria sobre o perfil da banda Raman do óxido de cério(IV) / In situ investigation of nonstoichiometry reversible influence over cerium(IV) oxide Raman band

Silva, Isaías de Castro, 1990- 26 August 2018 (has links)
Orientador: Italo Odone Mazali / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-26T22:22:44Z (GMT). No. of bitstreams: 1 Silva_IsaiasdeCastro_M.pdf: 4959698 bytes, checksum: 34689bf94c26337d3043ec67881ba30e (MD5) Previous issue date: 2015 / Resumo: Dado que o óxido de cério(IV) é um composto não-estequiométrico e que apresenta uma banda Raman sensível a mudanças na rede cristalina, utilizou-se a estratégia de oxidação e redução in situ empregando gases como agentes redutores e oxidantes para investigar as mudanças ocorridas no perfil da banda Raman do óxido de cério(IV), sintetizado em várias morfologias nanométricas com exposição específica de faces, em condições de controle da concentração de vacâncias de oxigênio não-estequiométricas. Foi observado um deslocamento para menores números de onda da freqüência do máximo da banda Raman quando a amostra se encontrava sob atmosfera redutora, e esse comportamento se mostrou reversível, de modo que a freqüência do máximo da banda deslocou-se para maiores números de onda quando em atmosfera oxidante. Esse deslocamento foi mais pronunciado na morfologia de nanobastões cominuídos, na qual predominam faces de índice {110}, que são favoráveis à formação de vacâncias de oxigênio não-estequiométricas. Ao correlacionar os resultados da espectroscopia Raman com outras técnicas sensíveis ao grau de não-estequiometria do composto, se observou aumento no parâmetro de rede na difratometria de raios X e perda de massa na determinação da capacidade de estoque de oxigênio, medida por termogravimetria, sob atmosfera redutora. As observações mostram que as responsáveis pelo deslocamento da frequência da banda Raman do óxido de cério(IV) são as vacâncias de oxigênio não-estequiométricas. Como certos espectros Raman apresentaram bandas assimétricas, a razão para tal poderia ser a ressonância de Fano, o que foi investigado variando-se a energia da radiação incidente. A razão para a assimetria não foi atribuída à ressonância de Fano, mas sim há outra banda relacionada a modos vibracionais de superfície. Por fim se comparou as atividades catalíticas dos cristais de diferentes morfologias de óxido de cério(IV) frente à oxidação de monóxido de carbono, sendo que a morfologia de nanobastões cominuídos apresentou melhor desempenho. Como o mecanismo de oxidação depende das vacâncias de oxigênio não-estequiométricas, a formação dessas é facilitada na morfologia de nanobastões cominuídos, e por isso o deslocamento da banda Raman é mais pronunciado nessa morfologia / Abstract: One remarking property of cerium(IV) oxide (CeO2) is its oxygen storage capacity (OSC). This property is related to the presence of oxygen vacancies, as CeO2 is a non-stoichiometric oxide. Once CeO2 presents only one Raman active mode, which is sensitive to changes in CeO2 lattice like the oxygen vacancies, it has been investigated the influence of oxygen vacancies over CeO2 Raman band. The crystals were synthesized in different nanometric morphologies, with exposure of specific facets. The samples were characterized by X-ray powder diffraction, transmission electron microscopy, OSC measurements by thermogravimetric equipment and Raman spectroscopy. Besides the microscopy, all other characterizations were performed with in situ control of temperature and atmosphere. The morphology with dominant {110} facets, favorable for oxygen vacancies generation, presents lattice parameter expansion, loss of mass and Raman band maximum red-shift after reduction with hydrogen-containing atmosphere, and sequent lattice parameter contraction, gain of mass and Raman band maximum blue-shift after oxidation with oxygen-containing atmosphere. These observations present reversible behavior as the atmospheres are alternated, consequence of generation or extinction of oxygen vacancies. Thereby, the correct morphology choice for a CeO2 crystal favors oxygen vacancies generation, and once generated they result in CeO2 Raman band maximum red-shift / Mestrado / Quimica Inorganica / Mestre em Química
1143

Análise comparativa dos padrões de covariação genética e fenotípica no crânio e mandíbula de Calomys expulsus (Rodentia: Muroidea) / Comparative analysis of phenotypic and genetic covariances in the skull and mandible of the vesper mouse Calomys expulsus (Rodentia: Muroidea)

Guilherme Rodrigues Gomes Garcia 27 April 2011 (has links)
Os padrões de covariância genética entre caracteres, expressos pela matriz de covariância aditiva G, desempenham um papel importante na evolução de morfologias complexas, visto que esta matriz influencia a direção e magnitude da resposta à seleção em uma população. Assumindo-se a estabilidade da matriz G ao longo do tempo, pode-se testar explicitamente hipóteses acerca da influência de processos evolutivos sobre a diversificação. Espera-se que esta matriz influencie os padrões expressos por sua equivalente fenotípica P, devido a contingências funcionais e ontogenéticas na relação entre genótipo e fenótipo, que levam à estruturação de modularidade nesta relação, de modo a otimizar a evolvabilidade. No presente trabalho, investiguei a estrutura da covariância genética no crânio e mandíbula de uma população do roedor sigmodontíneo Calomys expulsus, com o objetivo de estimar a similaridade entre covariâncias fenotípicas e genéticas; também avaliei a influência de padrões de modularidade sobre ambos os níveis de organização da variação morfológica. As matrizes P e G que obtive para o crânio e para a mandíbula se mostraram bastante similares no que diz respeito à sua estrutura de covariação e se relacionam parcialmente às hipótese de modularidade estabelecidas. Os resultados que obtive aqui são bastante similares àqueles obtidos para os mamíferos como um todo, portanto suportando a hipótese de estabilidade no padrão de covariâncias genéticas e fenotípicas na evolução do grupo. / Patterns of genetic covariance between characters (represented by the additive covariance matrix G) play an important role in the evolution of morphological complexes, since they influence the direction and norm of the response to selection in a population. Therefore, the assumption that G-matrices are stable through evolutionary timescales allows evolutionary biologists to infer the influence of evolutionary processes that operate over biological diversification. These matrices are also expected to influence the patterns expressed in their phenotypic counterparts (P-matrix), because of the imposition of multiple developmental and functional contingencies over the genotype/phenotype map, that leads to its modular organization in order to increase evolvability. Here, I have investigated patterns of genetic covariance structure in the skull and mandible of a population of the vesper mouse Calomys expulsus in order to estimate the level of similarity between additive and phenotypic covariances; I have also evaluated the influence of expected patterns of modularity over both levels of morphological variation. For either skull and mandible, I have obtained P- and G-matrices that are strongly similar in their structure; these matrices also support the modularity hypotheses for developmental and functional constrains, akin to the overall results obtained for mammals, thus supporting the hypothesis of stability in genetic and phenotypic covariance structure in mammalian evolution.
1144

The development of the EEG in the Gerbil

Bonner, Susan 01 January 1974 (has links)
No description available.
1145

Bite Force in Two Top Predators, the Great Barracuda, <em>Sphyraena barracuda</em> and Bull Shark <em>Carcharhinus leucas</em>, During Ontogeny

Habegger, María Laura 03 April 2009 (has links)
Functional morphologists have extensively used measurements of performance to investigate the relationship among form, function and ecology through ontogeny. Among different measurements of performance bite force play a crucial role influencing fitness. Although, bite force has been thoroughly investigated among vertebrates, the majority of the studies on fishes have been concentrated only in small species. Consequently, this is the first study that compares the bite force performance in two large marine predators, the great barracuda (Sphyraena barracuda) and bull shark (Carcharhinus leucas). Values of posterior bite force in S. barracuda varied from 3 - 258 N for an ontogenetic series of 27 individuals (23 - 130 cm, TL). Bite force as well as the majority of the biomechanical variables that contribute to it scaled with isometry in S. barracuda. Values of posterior bite force in C. leucas varied from 170 - 5,914 N for and ontogenetic series of 16 individuals (73 - 285 cm, TL). Bite force at the most anterior bite point scaled with positive allometry as well as the majority of the subdivisions of the adductive musculature that greatly contribute to bite force. Bite force performance in this two species showed strong differences, where S. barracuda has one of the lowest relative values of bite force among fishes and C. leucas has one of the largest ones. Additionally, the scaling patterns for bite force and most of the biomechanical variables investigated in this study differed among these two species. These results suggest that predatory success may be acquired by different strategies, and that the same ecological role in a marine ecosystem may be reached by having different bite force performance.
1146

Functional morphology and evolution of the adapiform dentition, with particular emphasis on the Asian Sivaladapidae

White, Jessica Lynn 01 January 2006 (has links)
This study utilizes two-dimensional geometric morphometric techniques to address molar shape variation in extinct and extant prosimians using the relative orientation of selected homologous molar landmarks (paraconid, protoconid, metaconid, entoconid, hypoconid, hypoconulid, metaconulid, and the intersection of the cristid obliqua with the protolophid). Molar shape was studied using Thin-Plate Splines analysis to explore variation using shape variables simultaneously, rather than by comparing inter-landmark distances, as in traditional studies. The sampled extant taxa included members from the Malagasy lemur families Lepilemuridae, Lemuridae, and Indriidae, as well as Asian Lorisidae. Extant taxa were categorized using taxonomic, as well as dietary, categories to determine if intra-sample variation was correlated with either category. Results suggest that frugivores (and gramnivores) generally exhibit a relatively wide anterior talonid basin and little trigonid torsion (observed as the angle of the protolophid relative to the long axis of the molar). Folivores, on the other hand, generally exhibit a constricted anterior talonid and higher degrees of trigonid torsion. Lorisid omnivores were found to exhibit constricted anterior talonids, but little trigonid torsion. The Thin-Plate Splines technique was also applied to a sample of three extinct adapiform families: Notharctidae, Adapidae, and Sivaladapidae. These comparisons were aimed at further exploration into dietary adaptation and diversity in extinct prosimians, and to specifically address the paleobiology of the Asian sivaladapids. Like their extant counterparts, adapiforms generally varied also in the relative orientation of the trigonid basin and in the dimensions of the talonid basin. In addition, the relative location of the paraconid also varied significantly within several adapiform families. Results of this study specifically highlight shape variation within several prosimian lineages, suggesting that a broader perspective of morphological diversity can be appreciated through analyzing adaptation within a particular family. For the sivaladapid genera, Sivaladapis and Hoanghonius, in particular, as well as North American Notharctidae, a molar shape similar to Nycticebus (an Asian loris) was noted. For Adapidae, a similarity with extant indriids was revealed. In summary, it is suggested here that multiple lines of morphological evidence should be employed to gain the broadest perspective of extinct primate adaptation.
1147

Development and metamorphosis in the male pedipalp of the cob-web spider Parasteatoda tepidariorum

Quade, Felix Simon Christian 01 February 2019 (has links)
No description available.
1148

Manus Descriptions of an Undescribed Mastodon from the Latest Miocene-Earliest Pliocene Gray Fossil Site, with Comparisons to other North American Proboscidean Taxa

Hart-Farrar, Brenna 01 December 2019 (has links)
A detailed morphological description of a proboscidean manus from the Gray Fossil Site (GFS), Gray, Tennessee is provided. Manus elements from an American mastodon (Mammut americanum), a Britt’s shovel-tusker (Amebelodon britti), an undescribed small gomphothere species, and a Columbian mammoth (Mammuthus columbi) are used for comparisons. Linear measurements indicate proportional differences between the GFS mastodon and other proboscidean taxa ranging from the Hemphillian to Rancholabrean land mammal ages. Possible pathologies are also described. The purpose of this study is to determine how the GFS mastodon differs in manus morphology and locomotion from different proboscidean taxa, including size, environmental, evolutionary, and taxonomic factors. Morphological differences are more pronounced in carpals and metacarpals in regard to shape, size, and orientation of articular surfaces but are not statistically compared due to the small sample size.
1149

Exploring sediment dynamics in coastal bays by numerical modelling and remote sensing

Zhang, Xiaohe 15 February 2021 (has links)
Coastal bays and salt marshes are buffer zones located at the interface between land and ocean, and provide ecologically and commercially important services worldwide. Unfortunately, their location makes them vulnerable and sensitive to sea-level rise (SLR), reduced sediment loads and anthropogenic modifications of the shoreline. Sediment budget and sediment availability are direct metrics for evaluating the resilience of salt marshes and coastal bays to various stressors (e.g. SLR). Salt marshes requires adequate sediment inputs to maintain their elevation with respect to sea level. Understanding sediment trajectories, sediment fluxes and sediment trapping capacities in different geomorphic unit facilitates efficient restorations and coastal management. In this research I used remote sensing, field observations and numerical modelling in the Plum Island Sound in Massachusetts, USA, to explore mechanisms controlling sediment dynamics and their feedbacks with SLR. The analysis of remote-sensed suspended sediment concentrations (SSC) reveals that a 5-year record (2013-2018) is sufficient to capture a representative range of meteorological and tidal conditions required to determine the main drivers of SSC dynamics in hydrodynamically-complex and small-scale coastal bays. The interplay between river and tidal flows dominated SSC dynamics in this estuary, whereas wind-driven resuspension had a more moderate effect. The SSC was higher during spring because of increased river discharge due to snowmelt. Tidal asymmetry also enhanced sediment resuspension during flood tides, possibly favoring deposition on marsh platforms. Together, water level, water-level rate of change, river discharge and wind speed were able to explain > 60% of the variability in the main channel SSC, thereby facilitating future prediction of SSC from these readily available variables. To determine the fate of cohesive sediments and spatial variations of trapping capacity in the system, a high-resolution (20 m) numerical model coupled to a vegetation module was developed. The results highlight the importance of the timing between sediment inputs and tidal phase and show that sediment discharged from tidal rivers deposit within the rivers themselves or in adjacent marshes. Most sediment is deposited in shallow tidal flats and channels and is unable to penetrate farther inside the marshes because of the limited water depths and velocities on the marsh platform. Trapping capacity of sediment in different intertidal subdomains decreases logarithmically with the ratio between advection length and the typical length of channels and tidal flats. Moreover, sediment deposition on the marsh decreases exponentially with distance from the channels and marsh edge. This decay rate is a function of settling velocity and the maximum value of water depth and velocity on the marsh platform. Bed sediment compositions were generated to further explore feedbacks between SLR, sediment dynamics and morphological changes. The results show SLR increases tidal prism and inundation depth, facilitating sediment deposition on the marsh platform. At the same time, SLR enhances ebb-dominated currents and increases sediment resuspension, reducing the sediment-trapping capacity of tidal flats and bays, leading to a negative sediment budget for the entire system. This bimodal distribution of sediment budget trajectories will have a profound impact on the morphology of coastal bays, increasing the difference in elevation between salt marshes and tidal flats and potentially affecting intertidal ecosystems. The results also clearly indicate that landforms lower with respect to the tidal frame are more affected by SLR than salt marshes. Therefore, Salt marshes, shallow bays, tidal flats, and barrier islands are inherently and physically connected systems, and evaluating the effect of SLR on salt marshes should involve all these units.
1150

Study on Hydro-morphological Characteristics of Meandering Channels with Groynes / 水制工を有する蛇行水路の水成地形特性に関する研究

KARKI, Saroj 24 September 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22049号 / 工博第4630号 / 新制||工||1722(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 中川 一, 教授 藤田 正治, 准教授 川池 健司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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