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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.
1

Ore mineralogy, geochemistry, and formation of the sediment-hosted sea floor massive sulfide deposits at Escanaba Trough, NE Pacific, with emphasis on the transport and deposition of gold

Törmänen, T. (Tuomo) 21 January 2004 (has links)
Abstract Recent sea floor sulfide deposits form when seawater, heated within the oceanic crust, discharges to the sea floor. Upon mixing with cold seawater, sulfide-forming elements such as sulfur, iron, copper, and zinc are precipitated from the fluid. Actively forming sea floor massive sulfide deposits are found from different lithologic and tectonic environments varying from mid-ocean ridges to back-arc spreading centers. At a few localities, sulfide deposits are associated with turbiditic sediments that cover the axial valley of the spreading center. The southern part (Escanaba Trough) of the Gorda Ridge (NE Pacific) is one such example. At Escanaba Trough, massive sulfide deposits are associated with small sediment hills, which were uplifted by the intrusion of sills and laccoliths within the sediments. Hydrothermal deposits are dominated by pyrrhotite-rich massive sulfides, with subordinate amounts of sulfate-rich precipitates and polymetallic sulfides. Compared to deposits hosted by volcanites, Escanaba Trough sulfides contain relatively low amounts of copper and zinc. However, the average gold concentration is relatively high for a sediment-hosted deposit, and is comparable with other, Au-enriched, sea floor sulfide deposits. Despite the relatively high Au concentration in many volcanic-hosted sea floor sulfide deposits, discrete Au grains are rare. They occur mostly with sphalerite, pyrite, chalcopyrite and tetrahedrite-tennantite. Sixteen of the pyrrhotite-rich samples from Escanaba Trough were found to contain visible Au grains. They occur mostly with native Bi and various BiTe phases, and to lesser degree, with Fe-Co sulfarsenides. Transport of Au in sea floor hydrothermal systems is attributed to the presence of Au(HS)2- complex, which is destabilized when the fluid mixes with seawater. Hydrothermal fluids are generally undersaturated with respect to Au complexes and additional mechanisms, such as remobilizing earlier precipitated Au is required to explain the high Au concentrations encountered in many deposits. At Escanaba Trough the mechanism is attributed to early precipitation of Bi as melt droplets, at temperatures greater its melting temperature, as liquid Bi is capable of collecting Au even from an undersaturated fluid. Upon cooling Au is exsolved from the Bi host as native Au or maldonite (Au2Bi).
2

Effect of recent L1 exposure on Spanish attrition : an eye-tracking study

Chamorro Galán, Gloria January 2013 (has links)
Previous research has shown L1 attrition to be selective (Gürel 2004) and often restricted to structures at the interfaces between syntax and context/pragmatics, but not to occur with syntactic properties that do not involve such interfaces (Interface Hypothesis, Sorace & Filiaci 2006). This is supported by many studies exploring cross-linguistic influence effects in interface structures, such as the production and/or interpretation of null versus overt pronominal subjects, not only in L1 attriters (Tsimpli et al. 2004, Montrul 2004) but also in other bilingual groups with different language combinations, such as early bilinguals (Paradis & Navarro 2003, Sorace et al. 2009), and advanced late bilinguals (Belletti et al. 2007, Rothman 2009). The current hypothesis is that individual L1 attrition affects only the ability to process interface structures but not knowledge representations themselves (Sorace 2011). In this thesis, we first compared a well-studied syntax-pragmatics interface phenomenon (pronominal subjects in Spanish) with a non-interface structure (the Spanish personal preposition a, also known as Differential Object Marking, DOM). In Spanish, the distribution of null and overt subject pronouns is pragmatically constrained, whereas the presence of the preposition just depends on the animacy and specificity of the direct object. Participants included a group of attrited speakers of L1 Spanish who had been living in the UK for a minimum of 5 years, and a group of Spanish monolinguals. Using a naturalness judgment task and eye tracking while reading, participants were presented with anaphoric sentences in which number cues matched or mismatched predicted antecedent preferences (i.e. null pronoun: subject preference; overt pronoun: object preference). The DOM study also used a mismatch paradigm, crossing preposition presence (al vs. el) with animacy, where an animate object requires the prepositional form al and an inanimate object requires the article el. Offline ratings revealed equal mismatch sensitivity for both groups of participants with both structures. However, eye-tracking measures showed that monolinguals were reliably more sensitive than attriters to the pronoun mismatch, while both groups showed equal on-line sensitivity to the DOM mismatch, which reveals that attrition affects interface structures, but not non-interface structures. Second, we investigated the effects of recent (re)exposure to L1 input on attrition. A second group of attriters carried out the same experiment after having been exposed exclusively to Spanish in a monolingual Spanish-speaking environment for a minimum of a week. Their eye-tracking results patterned with the monolingual group. This novel manipulation shows that attrition effects decrease as a result of L1 exposure, which reveals that bilinguals are sensitive to input changes and that attrition affects online sensitivity rather than causing a permanent change in speakers’ L1 grammatical representations.
3

Att förståskolbyggnader

Bjurström, Patrick January 2004 (has links)
Understanding School Buildingscompletes a study ofmodern Swedish school buildings and the ideas behind them. In aseries of case studies of seven schools built between 1953 and2001, changes in architecture have been found to reflectchanges in the ideas and practices of teaching and learning.The study has raised a number of questions, regarding currentdemands on school buildings. Problems and qualities of schoolbuildings demands on school buildings, problems and qualitiesof school buildings form the 1950s, 60s and 70s, problems foundand qualities lost in the process of changing such buildings,and the motives of architects involved in the design ofschools. In practical terms, the research method has includedobservations of buildings in use, interviews with directors,staff and pupils as well as architects, and the study ofliterature, documents and architectural drawings. Intheoretical terms, different perspectives of architecture havebeen discussed and applied, from the phenomenological approachof Norberg-Schulz to the space syntax theory of Hillier, frompractical, social use of symbolic meaning and aesthetics.Finally, some philosophical themes on art, architecture andsociety, from Dewey, Shusterman, Scruton and Sartre have beenintroduced. Partly diverging from the case study model of Yin, the studydoes not simply aim at verifying or falsifying a hypothesis. Ata point in the study, each case is explained in a morenarrative manner. In the final analysis, understanding schoolbuildings in shown to require a multifaceted view. A schoolbuilding must be seen in a historic/political perspective, as atool for teaching and learning and as the life-world ofteachers and pupils. In cases discussed, a school building isalso the object of strong pedagogical or social intensions ofan architect. In other term, a study of school buildings mustbe a study in pragmatist aesthetics. Keywords:School building, architectural theory, recentsocial history of architecture, intention, experience,pragmatist aesthetics
4

K-State Alumni Association: neat/marketing recent graduate retention analysis

Hobbs, Brittani January 1900 (has links)
Master of Science / Department of Journalism and Mass Communications / Robert C. Pearce / The K-State Alumni Association has the highest percentage of graduates in the Big 12 who are members of the association. As a result, there is a strong network of alumni spanning more than 150,000 living alumni internationally and throughout the United States. This project seeks to utilize the relationship management theory to review current marketing strategies and develop new strategies to increase retention rates of alumni to the association after their one free year of membership, a gift provided to undergraduate students by their perspective college. The focus of the relationship management theory is about building personal relationships, which is in line with the K-State Alumni Association’s mission statement, “Enhancing our Kansas State University family through lifelong involvement.” The recommendations were created to assist the efforts of the Alumni Association to continue to reach out to alumni to meet them where they are at by utilizing media and new programs.
5

História seletiva e demográfica do MHC na América do Sul: um estudo de populações nativas e urbanas / Selective and demographic history of MHC in South America: a study of native and urban populations

Maia, Maria Helena Thomaz 29 April 2013 (has links)
Um dos maiores desafios em estudos de genética de populações é a diferenciação entre os sinais de diversidade genética resultantes de efeitos estocásticos dos sinais de seleção natural. Neste trabalho, o objetivo central foi inferir a história evolutiva, em termos de demografia e seleção natural, do MHC e alguns de seus genes HLA de classe II (HLA-DRB1, -DQB1 e -DPB1). A primeira estratégia usada foi sequenciar os referidos genes em 14 populações ameríndias e, em conjunto com dados já publicados em outras populações ameríndias e não ameríndias, contrastou-se sua distribuição de alelos, diversidade genética intra e interpopulacional e testes de neutralidade com as mesmas estatísticas obtidas a partir de 54 STR genômicos genotipados para estas mesmas populações. Em nossos resultados verificamos: a) a maior variabilidade dos genes HLA em relação aos STR, b) a menor variabilidade de ameríndios se comparados com não ameríndios e c) correlação das estimativas de FST obtidas de STR com as obtidas dos genes HLA. Esses resultados indicam a ação da demografia como principal responsável pelos padrões encontrados. No entanto, outras evidências sugerem um padrão de diversidade genética que não pode ser explicado por mera ação do acaso, como por exemplo: a) o grande número e dispersão geográfica de alelos privados e/ou mais prevalentes em ameríndios (vinte vezes mais frequentes) para HLA-DRB1, b) a não correlação das estimativas de diversidade genética intrapopulacional obtidas de genes HLA com as obtidas de STR, c) os maiores valores de FST para genes HLA em comparação com o FST de STR e a d) ausência de correlação dos valores de D de Tajima (para HLA) com a estimativa &beta; (para STR). Assim, apesar da grande influência de fatores estocásticos, os sinais de seleção natural são perceptíveis. A segunda abordagem investigou sinais de seleção recente na região do MHC na população miscigenada de Belém do Pará (n=202), utilizando como ferramenta a comparação entre os componentes de ancestralidade estimados para a região do MHC (com sete STR) com os observados no restante do genoma (54 STR) para detecção de desvios na ancestralidade das populações parentais. As proporções de ancestralidade média para os STR em Belém (africana= 0,19, europeia= 0,51 e ameríndia=0,30), foram diferentes das estimadas para os marcadores do MHC (africana= 0,23, europeia= 0,67 e ameríndia=0,11), sendo as diferenças entre as estimativas ameríndia e europeia significativa (Wilcoxon; p<0,0001). Além disso, os valores de FST observados eram maiores entre Belém e Ameríndios, considerando-se os STR do MHC. É possível concluir, portanto, que foi observada uma perda de componente genético ameríndio na região do MHC durante o processo de miscigenação, quando contrastarmos com as estimativas genômicas, sugerindo ação de seleção natural recente. Em conjunto, nossos resultados mostram que tanto a seleção natural como a demografia moldaram a variação genética em genes HLA, e que usando métodos apropriados, incluindo o mapeamento por miscigenação, eventos de seleção natural que ocorreram em escalas de tempo recentes podem ser detectados / One of the greatest challenges on the Genetics Populations Studies is the differentiation among the resulting genetic signs of diversity from the stochastic signs of natural selection. On the present study, the main objective was inferring the evolutive history, in terms of demography and natural selection, from the MHC and some of its HLA class II genes (HLA-DRB1, -DQB1 e -DPB1). The first strategy used was sequentiating the referred genes in 14 Amerindian populations and, in conjunction with data already published in other Amerindian and non-Amerindian populations, we have contrasted its distribution in alleles, intra and inter-populational genetic diversity and neutrality tests with the same statistics obtained from 54 STR genomics genotyped for these same populations. In our results we have verified: a) greater variability of the HLA genes in relation to the STR, b) greater variability of Amerindians, if compared to non-Amerindians and c) correlation of the estimates of FST obtained from STR with the ones obtained from the HLA genes. These results indicate the demography action as the main responsible for the found patterns. However, other evidences suggest a pattern of genetic diversity that can\'t be explained only by chance, as for example: a) the great number and geographic dispersion of the private alleles and/or more prevalent in the Amerindians (twenty times more frequent) for HLA-DRB1, b) a non-correlation of the estimates on interpopulational genetic diversity obtained from HLA genes with the ones obtained from STR, c) greater values of FST for the HLA genes, in comparison with the FST of STR and d) absence of correlation on the D values of Tajima (for HLA) with &beta; estimates (for STR). So, despite the great influence of stochastic factors, the signs of natural selection are perceptible. The second approach investigated signs of recent selection in the MHC region of the admixture population of Belém do Pará (n=202), using as tool the comparison between the ancestrality components estimated for the MHC region (with seven STR) with the ones observed on the remaining genome (54 STR) for the detection of deviations on the ancestrality of the parental populations. The medium ancestrality proportions for the STR in Belém (African=0,19, European=0,51 and Amerindian=0,30), was different from the estimates for the MHC markers (African=0,23, European=0,67 and Amerindian=0,11), being significative the differences between Amerindian and European estimates (Wilcoxon; p<0,0001). Furthermore, the FST values observed were greater between Belém and the Amerindians, considering the STR from the MHC. It\'s then possible to get to the conclusion that a loss in Amerindian genetic component was observed in the MHC region during the miscegenation process, when contrasted with the genomic estimates, suggesting recent action of natural selection. In whole, our data show that even natural selection as demography have molded the genetic variation in the HLA genes, and by using the appropriated methods, including the miscegenation mapping, natural selection events occurred in recent time scales can be detected
6

Employment problems of recent Sri Lankan skilled immigrants in Australia

Liyanaratchi, Karunatissa Hal, not supplied January 2006 (has links)
The aim of this thesis is to examine the employment situation of recent Sri Lankan skilled immigrants in Victoria and whether they need further education and re-training in order to face emerging technological changes or to update their skills. The underemployment and unemployment problem faced by the Sri Lankan skilled immigrants is an issue for both the Australian economy and the migrants. The following set of premises has been used for the study; a) the migrants' educational qualifications, training and skills are recognised by the Department of Immigration Multicultural & Indigenous Affairs (DIMIA) of Australia, b) they are having difficulties in finding and keeping suitable jobs, although some have found employment commensurate with their qualifications, and c) the reason for their difficulties are many and complex. The essential format of the research is to identify and explain the many and complex reasons for such unemployment or underemployment. This study is based upon a survey of three contrasting Sri Lankan immigrant groups: a) trade persons and related workers with certificates or no qualifications b) technical or associate professionals with diploma or associate diploma level qualifications and c) professionals (engineers) with university degrees or their equivalent. Subjects for the surveys were through three relevant alumni organisations based in Melbourne, and through personal contact. The survey was supplemented with some applying qualitative methods that involved unstructured interviews, and small case studies. Recommendations have been proposed to assist in solving the issues that were identified through the study. Although the recommendations mentioned in the study provide a starting point, it is stressed that further research is needed to be undertaken before implementing such suggested solutions. Therefore, this thesis serves as a foundation in highlighting the loss of services of skilled immigrants within the labour market in Australia, particularly among the Sri Lankan community, and proposing recommendations to address this issue.
7

Att förståskolbyggnader

Bjurström, Patrick January 2004 (has links)
<p><i>Understanding School Buildings</i>completes a study ofmodern Swedish school buildings and the ideas behind them. In aseries of case studies of seven schools built between 1953 and2001, changes in architecture have been found to reflectchanges in the ideas and practices of teaching and learning.The study has raised a number of questions, regarding currentdemands on school buildings. Problems and qualities of schoolbuildings demands on school buildings, problems and qualitiesof school buildings form the 1950s, 60s and 70s, problems foundand qualities lost in the process of changing such buildings,and the motives of architects involved in the design ofschools.</p><p>In practical terms, the research method has includedobservations of buildings in use, interviews with directors,staff and pupils as well as architects, and the study ofliterature, documents and architectural drawings. Intheoretical terms, different perspectives of architecture havebeen discussed and applied, from the phenomenological approachof Norberg-Schulz to the space syntax theory of Hillier, frompractical, social use of symbolic meaning and aesthetics.Finally, some philosophical themes on art, architecture andsociety, from Dewey, Shusterman, Scruton and Sartre have beenintroduced.</p><p>Partly diverging from the case study model of Yin, the studydoes not simply aim at verifying or falsifying a hypothesis. Ata point in the study, each case is explained in a morenarrative manner. In the final analysis, understanding schoolbuildings in shown to require a multifaceted view. A schoolbuilding must be seen in a historic/political perspective, as atool for teaching and learning and as the life-world ofteachers and pupils. In cases discussed, a school building isalso the object of strong pedagogical or social intensions ofan architect. In other term, a study of school buildings mustbe a study in pragmatist aesthetics.</p><p><b>Keywords:</b>School building, architectural theory, recentsocial history of architecture, intention, experience,pragmatist aesthetics</p>
8

História seletiva e demográfica do MHC na América do Sul: um estudo de populações nativas e urbanas / Selective and demographic history of MHC in South America: a study of native and urban populations

Maria Helena Thomaz Maia 29 April 2013 (has links)
Um dos maiores desafios em estudos de genética de populações é a diferenciação entre os sinais de diversidade genética resultantes de efeitos estocásticos dos sinais de seleção natural. Neste trabalho, o objetivo central foi inferir a história evolutiva, em termos de demografia e seleção natural, do MHC e alguns de seus genes HLA de classe II (HLA-DRB1, -DQB1 e -DPB1). A primeira estratégia usada foi sequenciar os referidos genes em 14 populações ameríndias e, em conjunto com dados já publicados em outras populações ameríndias e não ameríndias, contrastou-se sua distribuição de alelos, diversidade genética intra e interpopulacional e testes de neutralidade com as mesmas estatísticas obtidas a partir de 54 STR genômicos genotipados para estas mesmas populações. Em nossos resultados verificamos: a) a maior variabilidade dos genes HLA em relação aos STR, b) a menor variabilidade de ameríndios se comparados com não ameríndios e c) correlação das estimativas de FST obtidas de STR com as obtidas dos genes HLA. Esses resultados indicam a ação da demografia como principal responsável pelos padrões encontrados. No entanto, outras evidências sugerem um padrão de diversidade genética que não pode ser explicado por mera ação do acaso, como por exemplo: a) o grande número e dispersão geográfica de alelos privados e/ou mais prevalentes em ameríndios (vinte vezes mais frequentes) para HLA-DRB1, b) a não correlação das estimativas de diversidade genética intrapopulacional obtidas de genes HLA com as obtidas de STR, c) os maiores valores de FST para genes HLA em comparação com o FST de STR e a d) ausência de correlação dos valores de D de Tajima (para HLA) com a estimativa &beta; (para STR). Assim, apesar da grande influência de fatores estocásticos, os sinais de seleção natural são perceptíveis. A segunda abordagem investigou sinais de seleção recente na região do MHC na população miscigenada de Belém do Pará (n=202), utilizando como ferramenta a comparação entre os componentes de ancestralidade estimados para a região do MHC (com sete STR) com os observados no restante do genoma (54 STR) para detecção de desvios na ancestralidade das populações parentais. As proporções de ancestralidade média para os STR em Belém (africana= 0,19, europeia= 0,51 e ameríndia=0,30), foram diferentes das estimadas para os marcadores do MHC (africana= 0,23, europeia= 0,67 e ameríndia=0,11), sendo as diferenças entre as estimativas ameríndia e europeia significativa (Wilcoxon; p<0,0001). Além disso, os valores de FST observados eram maiores entre Belém e Ameríndios, considerando-se os STR do MHC. É possível concluir, portanto, que foi observada uma perda de componente genético ameríndio na região do MHC durante o processo de miscigenação, quando contrastarmos com as estimativas genômicas, sugerindo ação de seleção natural recente. Em conjunto, nossos resultados mostram que tanto a seleção natural como a demografia moldaram a variação genética em genes HLA, e que usando métodos apropriados, incluindo o mapeamento por miscigenação, eventos de seleção natural que ocorreram em escalas de tempo recentes podem ser detectados / One of the greatest challenges on the Genetics Populations Studies is the differentiation among the resulting genetic signs of diversity from the stochastic signs of natural selection. On the present study, the main objective was inferring the evolutive history, in terms of demography and natural selection, from the MHC and some of its HLA class II genes (HLA-DRB1, -DQB1 e -DPB1). The first strategy used was sequentiating the referred genes in 14 Amerindian populations and, in conjunction with data already published in other Amerindian and non-Amerindian populations, we have contrasted its distribution in alleles, intra and inter-populational genetic diversity and neutrality tests with the same statistics obtained from 54 STR genomics genotyped for these same populations. In our results we have verified: a) greater variability of the HLA genes in relation to the STR, b) greater variability of Amerindians, if compared to non-Amerindians and c) correlation of the estimates of FST obtained from STR with the ones obtained from the HLA genes. These results indicate the demography action as the main responsible for the found patterns. However, other evidences suggest a pattern of genetic diversity that can\'t be explained only by chance, as for example: a) the great number and geographic dispersion of the private alleles and/or more prevalent in the Amerindians (twenty times more frequent) for HLA-DRB1, b) a non-correlation of the estimates on interpopulational genetic diversity obtained from HLA genes with the ones obtained from STR, c) greater values of FST for the HLA genes, in comparison with the FST of STR and d) absence of correlation on the D values of Tajima (for HLA) with &beta; estimates (for STR). So, despite the great influence of stochastic factors, the signs of natural selection are perceptible. The second approach investigated signs of recent selection in the MHC region of the admixture population of Belém do Pará (n=202), using as tool the comparison between the ancestrality components estimated for the MHC region (with seven STR) with the ones observed on the remaining genome (54 STR) for the detection of deviations on the ancestrality of the parental populations. The medium ancestrality proportions for the STR in Belém (African=0,19, European=0,51 and Amerindian=0,30), was different from the estimates for the MHC markers (African=0,23, European=0,67 and Amerindian=0,11), being significative the differences between Amerindian and European estimates (Wilcoxon; p<0,0001). Furthermore, the FST values observed were greater between Belém and the Amerindians, considering the STR from the MHC. It\'s then possible to get to the conclusion that a loss in Amerindian genetic component was observed in the MHC region during the miscegenation process, when contrasted with the genomic estimates, suggesting recent action of natural selection. In whole, our data show that even natural selection as demography have molded the genetic variation in the HLA genes, and by using the appropriated methods, including the miscegenation mapping, natural selection events occurred in recent time scales can be detected
9

Preadolescent Developmental Tasks in Recent Fiction

Franklin, Joseph M. 08 1900 (has links)
The problem of this study is to determine if there are fictional books usable by teachers in helping preadolescent boys solve their problems of adjustment. The problem involves the analyses of twenty-five fiction books taken from those books listed by Virginia Bryson Blair in her study, "Directed Reading through the Library for Improving the Social Adjustment of Older Children."
10

Optimum System Modelling Using Recent Gradient Methods

Markettos, Nicholas Denis 04 1900 (has links)
<p> A study of gradient optimization techniques, in particular as applied to system modelling problems, is made. Three efficient techniques are used to derive optimum second-order and third-order models for a seventh-order system. The optimization techniques are the Fletcher-Powell method, a more recent method proposed by Fletcher and a method based on a more general objective function proposed by Jacobson and Oksman.</p> <p> The approximation is carried out in the time domain. Least squares and least pth criteria are used, and almost minimax results are obtained for large values of p. Values of p up to 10^12 are successfully used. The results are compared with other minimax type algorithms.</p> / Thesis / Master of Engineering (MEngr)

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