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Gosselin, Marie-Pierre. "Vectorisation de petits acides nucléiques par des lipopolyplexes : application au cancer du sein." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2017/document.
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Au cours de cette thèse, j’ai utilisé des complexes composés d’acides nucléiques, d’un polymère cationique et de liposomes cationiques appelés Lipopolyplexes pour formuler des siRNA (LPRi) et un leurre ADN (LPD) afin inhiber la croissance des cellules 4T1, un modèle murin de carcinome mammaire. Dans une première étude, des injections systémique ou endotrachéale de LPRi avec des siRNA anti-luciférase n’ont pas permis d’inhiber l’expression de la luciférase dans des métastases pulmonaires induites par des cellules 4T1-luciférase. A partir de ces résultats, les LPRi ont été améliorés en ciblant les cellules 4T1 avec le peptide uPA et/ou RGDc ou l’acide folique incorporés aux liposomes selon diverses approches. Les formulations obtenues ont été caractérisées, leur endocytose et l’effet siRNA mesurés in vitro. Cette deuxième partie a permis d’établir que les LPRi décorés avec du folate étaient la meilleure formulation ciblée. Dans une troisième partie, l’inhibition de la prolifération des cellules 4T1 a été recherchée en ciblant le facteur de transcription STAT3. Des LPRi anti-STAT3 ont montré une très bonne efficacité pour inhiber STAT3, mais sans effet antiprolifératif significatif. Des LPD anti-STAT3 ont montré un très bon effet antiprolifératif, celui-ci étant renforcé lorsqu’une co-délivrance siRNA/leurre ADN (LPRiD) a été réalisée. In vivo, un délai de la croissance des tumeurs 4T1 a été observé après co-délivrance siRNA/leurre ADN. Cette thèse a permis de montrer l’efficacité des lipopolyplexes pour la délivrance combinée de siRNA et de leurre ADN dans les cellules tumorales 4T1. Ils indiquent que des études sont cependant nécessaires pour augmenter leur délivrance in vivo dans la tumeurDuring this thesis, I used complexes made with nucleic acids, cationic polymer and cationic liposomes called Lipopolyplexes to formulate siRNA (LPRi) and DNA molecular decoy (LPD) in order to inhibit the growth of 4T1 cells, a murine model of mammary carcinoma. In a first study, systemic or endotracheal injections of LPRi comprising anti-luciferase siRNA did not allow luciferase inhibition in pulmonary metastases induced by 4T1-Luc cells. From these results, LPRi were improved by targeting 4T1 cells using incorporation, by different means, of uPA and/or RGDc peptide or folic acid in liposomes. Resulted formulations were characterized, their internalization and siRNA transfection efficiency were measured in vitro. This second part showed that folate targeting of LPRi was the best formulation. In a third part, proliferation inhibition of 4T1 cells was investigated by targeting the STAT3 transcription factor. Anti-STAT3 siRNA LPRi showed very good efficacy in inhibiting STAT3, but without significant antiproliferative effect. Anti-STAT3 decoy LPD showed a very good antiproliferative effect, the latter being reinforced when co-delivery siRNA/DNA decoy (LPRiD) was performed. In vivo, a growth retardation of 4T1 tumors was observed after co-delivery siRNA/DNA decoy. This thesis demonstrated the effectiveness of lipopolyplexes for combined delivery of siRNA and DNA decoy in the 4T1 tumor cells. Some studies are however required to increase their in vivo delivery into the tumor
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Silva, Nicolle Camilla Rodrigues da. "Influência da composição de lipídeos da dieta no desenvolvimento do carcinoma mamário murino 4T1." Universidade Federal de Minas Gerais, 2014. http://hdl.handle.net/1843/BUBD-9MYLBM.
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Dietary lipids have been shown to influence breast cancer development at several stages in the carcinogenic process. Thus, the aim of this study was to investigate the effect oils,containing low n-6/n-3 ratio, in tumor development and metastatic dissemination of 4T1 murine mammary carcinoma. BALB/c mice were randomly divided into four groups of 14 animals each fed semisynthetic AIN-93G diet containing 4g/100g soybean oil (Control), canola oil (Canola), fish oil (Fish) or flaxseed oil (linseed). The animals were fed ad libitum for 50 days, and on the 30th day seven animals in each group were inoculated with 4T1 cells (2.5 x 106) and named: Control 4T1, Canola 4T1, Fish 4T1 and Flaxseed 4T1. Body weight was recorded weekly. Cholesterol and triglycerides were determined by enzymatic assay. Fractionation of serum lipoproteins was performed by Fast Protein Liquid Chromatografy system. Quantification of hepatic lipids and cecal was performed as described by Folch et al. Assessment of lipid peroxidation was based on the determination of concentration of thiobarbituric acid reactive substances (TBARS). For histological analysis of the primary tumor and metastases, samples were collected, fixed and intended for cutting and staining with hematoxylin & eosin, and for blades for immunohistochemistry to identify CDC47. Further biochemical analyzes for assessing inflammation were conducted by plasma levels of the enzymes N-acetyl-beta-D-glucosaminidase (NAG) and myeloperoxidase (MPO), angiogenic, through the levels of vascular endothelial growth factor (VEGF) and hemoglobin (Hb), and the participation of the cytokine TNF-. There was no change in body weight of the animals during the experimental period. The animals in the Control 4T1 group decreased adduced lipoprotein cholesterol and increased fecal excretion of total lipids, cholesterol and triglycerides compared to Control group. The Flaxseed 4T1 group had increased cholesterol and triglycerides circulating in relation to Linseed and Control 4T1 groups and decreased lipid content in the liver compared to Flaxseed group. Likewise, the Fish 4T1 group had higher levels of circulating triglycerides in relation to Fish group, but had lower triglyceride content in the liver compared to the other groups with tumor. Canola 4T1 group had lower hepatic levels of TBARS. No change in tumor growth and metastasis number among the groups. In relation to cell proliferation, Canola 4T1 group had higher expression of CDC47 protein compared to Control 4T1 group. The Fish 4T1 group showed increased MPO and NAG reduction in tumor site. No significant change was observed in the Hb concentration, however, increased by VEGF in Fish 4T1 group compared to other groups. Furthermore there was no change of TNF- in the tumor site. This present study that showed different oils did not alter tumor growth and the number of metastases, but exert distinct effects on lipid metabolism, inflammatory and angiogenic processes effects, and cellular proliferation in murine mammary carcinoma 4T1 model.Os lipídeos da dieta têm demonstrado influenciar o desenvolvimento do câncer da mama em vários estágios do processo cancerígeno. Dessa forma, o objetivo do presente trabalho foi investigar o efeito de diferentes óleos, contendo baixa relação n-6/n-3, no desenvolvimento neoplásico e na disseminação metastática do carcinoma mamário murino 4T1. Camundongos BALB/c fêmeas foram distribuídos aleatoriamente em quatro grupos com 14 animais cada, alimentados com dieta semi-sintética AIN-93G contendo 4g/100g de óleo de soja (Controle), óleo de canola (Canola), óleo de peixe (Peixe) ou óleo de linhaça (Linhaça). Os animais foram alimentados ad libitum por 50 dias, sendo que, no 30º dia sete animais de cada grupo foram inoculados com células 4T1 (2,5 x 106) e denominados: Controle 4T1, Canola 4T1, Peixe 4T1 e Linhaça 4T1. Peso corporal foi registrado semanalmente. Colesterol e triglicerídeos foram determinados por ensaio enzimático. O fracionamento das lipoproteínas séricas foi realizado pelo sistema de Fast Protein Liquid Chromatografy. A quantificação de lipídeos hepáticos e cecais foi feita conforme descrito por Folch e colaboradores. A avaliação da peroxidação lipídica baseou-se na dosagem da concentração de substâncias reativas ao ácido tiobarbitúrico (TBARS). Para análise histológica do tumor primário e metástases, as amostras foram coletadas, fixadas e destinadas para cortes e coloração com Hematoxilina & Eosina, e para produção de lâminas para imuno-histoquímica para identificação de CDC47. Foram realizadas análises bioquímicas para avaliação do processo inflamatório, por meio das dosagens das enzimas N-Acetil-ß-D-Glicosaminidase (NAG) e mieloperoxidase (MPO), angiogênicos, através dos níveis de fator de crescimento vascular endotelial (VEGF) e hemoglobina (Hb), e a participação da citocina TNF-. Não houve alteração do peso corporal dos animais ao longo do período experimental. Os animais do grupo Controle 4T1 tiveram redução de colesterol carreado nas lipoproteínas e maior excreção fecal de lipídeos totais, colesterol e triglicerídeos comparado ao grupo Controle. O grupo Linhaça 4T1 apresentou aumento de colesterol e de triglicerídeos circulantes em relação aos grupos Linhaça e Controle 4T1 e diminuição do conteúdo de lipídeos hepáticos comparado ao grupo Linhaça. Da mesma forma, o grupo Peixe 4T1 apresentou maiores níveis de triglicerídeos circulantes em relação ao grupo Peixe, porém mostrou menor conteúdo de triglicerídeos no fígado em relação aos demais grupos com tumor. O grupo Canola 4T1 teve menores níveis hepáticos de TBARS. Não houve alteração no crescimento do tumor e número metástases entre os grupos avaliados. Em relação à proliferação celular, o grupo Canola 4T1 teve maior expressão da proteína CDC47 em relação ao grupo Controle 4T1. O grupo Peixe 4T1 apresentou aumento de MPO e redução de NAG no sítio tumoral. Não foi observada alteração significativa na concentração de Hb, porém, houve aumento de VEGF no grupo Peixe 4T1 em relação aos demais grupos. Ademais não houve alteração de TNF- no sítio tumoral. O presente estudo demonstrou que os diferentes óleos, não modificaram o crescimento do tumor e metástases, mas exercem efeitos distintos sobre o metabolismo lipídico, processos angiogênicos e inflamatórios, e na proliferação celular em modelo de carcinoma mamário murino 4T1.
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Souza, Cristina Maria de. "Carcinoma mamário murino 4T1: características morfológicas, imunofenotípicas, bioquímicas e ensaios pré-clínicos com talidomida/ carboplatina." Universidade Federal de Minas Gerais, 2013. http://hdl.handle.net/1843/BUOS-99MH3V.
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4T1 murine mammary carcinoma is a widely used experimental model in the evaluation and better understanding of tumor biology. This is a highly tumorigenic cell line and invasive and metastasis are observed in several organs. This study aims to characterize the morphological, immunophenotypic, biochemical and preclinical trials with thalidomide/ carboplatin in the development of murine 4T1 mammary carcinoma in Balb/c. For this study all animals were inoculated with 2.5 x 106 4T1 mammary carcinoma cells in the left flank (sub-cutaneous). After implantation tumor growth was monitored at different times of development in accordance with the study protocol. Morphologically, the 4T1 murine mammary carcinoma shows malignant epithelial proliferation in solid arrangement with proliferation of pleomorphic cells and high mitotic index. The results suggest that this experimental tumor mitotic index, and the number of apoptotic vessels are directly related to tumor evolution. The results immunohistochemical analysis demonstrated positive for hormone receptors, cytokeratin AE1/AE3, receptors, and markers of cell proliferation of blood vessels. Biochemical tests were also conducted in order to evaluate the role of angiogenic and inflammatory processes in tumor progression. Our results demonstrate that pro-angiogenic cytokines (VEGF), inflammatory (TNF-), macrophages and neutrophils participate actively in the development of murine 4T1 mammary carcinoma, and metastases. Aiming to suggest alternative therapies including greater specificity of antitumor chemotherapeutic agent, low toxicity and possible drug combinations, three trials were proposed. When evaluating the effect of treatment with thalidomide (150 mg/kg/day) on tumor growth in mice 4T1 Balb/c was observed that thalidomide reduces neoplastic growth by controlling neovascularization and recruitment of inflammatory cells in the tumor. Already administration of carboplatin (100mg/kg) was able to reduce by 50% the tumor volume and number of pulmonary metastases, the rate of cell proliferation and vascularization of tumors. Finally, to evaluate the effect of combination thalidomide/ carboplatin in 4T1 tumor growth was observed that this treatment regimen caused greater reduction in tumor size and number of lung metastases as compared to isolated treatments and increased survival of the animals.O carcinoma mamário murino 4T1 é um modelo experimental muito utilizado na avaliação e melhor compreensão da biologia dos tumores. Trata-se de uma linhagem celular altamente tumorigênica e invasiva, onde são observadas metástases em diversos órgãos. O presente trabalho tem como objetivo caracterizar os aspectos morfológicos, imunofenotípicos, bioquímicos e ensaios pré-clínicos com talidomida/carboplatina no desenvolvimento do carcinoma mamário murino 4T1 em camundongos Balb/c. Para a realização deste estudo todos os animais foram inoculados com 2,5 x 106 células do carcinoma mamário 4T1 no flanco esquerdo (sub-cutâneo). Após a implantação o crescimento do tumor foi acompanhado em diferentes tempos de desenvolvimento de acordo com protocolo de estudo. Morfologicamente, o carcinoma mamário murino 4T1 apresenta proliferação epitelial maligna em arranjo sólido, com proliferação de células pleomórficas e elevado índice mitótico. Os resultados sugerem que nesse tumor experimental o índice mitótico, apoptótico e o número de vasos estão diretamente relacionados com a evolução tumoral. Na análise imuno-histoquímica determinou-se positividade para os receptores hormonais, citoqueratina AE1/AE3, receptores de proliferação celular e marcadores de vasos sanguíneos. Testes bioquímicos também foram realizados com o intuito de avaliar a participação dos processos angiogênicos e inflamatórios na progressão tumoral. Nossos resultados demonstram que citocinas pro-angiogênica (VEGF), inflamatórias (TNF-), macrófagos e neutrófilos participam ativamente do desenvolvimento do carcinoma mamário murino 4T1, assim como nas metástases. Com o objetivo de sugerir alternativas de terapias antitumorais, incluindo maior especificidade do agente quimioterápico, baixa toxicidade e possibilidade de associação de drogas, três ensaios foram propostos. Ao avaliar os efeitos do tratamento com talidomida (150 mg/Kg/dia) no crescimento do tumor 4T1 em camundongos Balb/c foi possível observar que a talidomida reduz o desenvolvimento neoplásico ao controlar a neovascularização e recrutamento de células inflamatórias neste tumor. Já administração de carboplatina (100mg/kg) foi capaz de reduzir em 50% o volume do tumor, o número de metástases pulmonares, a taxa de proliferação celular e vascularização dos tumores. Por fim, ao avaliar o efeito da associação talidomida/carboplatina no crescimento do tumor 4T1 foi possível observar que este esquema terapêutico provocou maior redução no tamanho do tumor e no número de metástases pulmonares quanto comparados aos tratamentos isolados e aumento na sobrevida dos animais.
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Caffaro, Leonardo Affonso Massabki. "Influência da estimulação elétrica nervosa transcutânea no crescimento de carcinoma 4T1 em glândula mamária de camundongos." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/5/5170/tde-06062017-083836/.
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O objetivo deste estudo foi avaliar a influência da TENS no crescimento do tumor e área de necrose no tecido viável do carcinoma 4T1 em glândula mamária de camundongos. 22 camundongos Balb/c foram dividos em três grupos e submetidos à inoculação de células 4T1 e tratados por 20 minutos durante 10 dias: grupo do placebo (GP) estimulado com a intensidade zerada; grupo de alta frequência (GAF), tratados com frequência de 100 Hertz (Hz) e o grupo de baixa frequência (GBF), com frequência de 10 Hz. Os demais parâmetros da TENS foram duração do pulso - 200 microssegundos (?s) e intensidade sensorial. A intensidade foi reajustada em 1,0 mA a cada cinco minutos nos grupos GAF e GBF para evitar a acomodação da corrente. O crescimento do tumor foi mensurado seis vezes por meio de um paquímetro digital e depois de 10 sessões de tratamento, os animais foram eutanasiados por injeção de xilazina e quetamina. Os tumores foram extirpados para análise histológica. O teste Two-way ANOVA de medidas repetidas mostrou que houve um aumento no volume do tumor em todos os grupos (p < 0,001) e não houve diferença estatisticamente significante na relação entre grupos e tempo (p > 0,05). O One-way ANOVA mostrou que não houve diferença estatisticamente significante entre os grupos para área de necrose no tecido neoplásico viável (p > 0,05). Concluiu-se que a TENS não influenciou o crescimento tumoral do carcinoma 4T1The aim of this study was to evaluate the influence of TENS in tumor growth and necrotic area in viable tissue of 4T1 mammary gland carcinoma in mice. 22 Balb/c mice were subjected to inoculation of 4T1 cells and were divided into 3 groups subjected to 20 minutes of treatment for 10 days: placebo group (PG) stimulated with intensity at zero; High frequency group (HFG), treated with a frequency of 100 Hertz (Hz) and Low frequency group (LFG), with 10 Hz frequency. The others TENS parameters were pulse duration - 200 microseconds (?s) and sensory intensity. The intensity was readjusted on 1.0 mA every five minutes in HFG and LFG groups to avoid the current accommodation. The tumor growth was measured by a caliper six times and after 10 treatment sessions, the animals were euthanized by injection of xylazine and ketamine. The tumors were excised for histological analysis. Two-way ANOVA for repeated measures showed that there was an increase in tumor volume in all groups (p < 0.001) and there was no statistically significant difference in the relationship among groups and time (p > 0.05). One-way ANOVA showed that there was no statistically difference between groups for necrotic area in viable neoplastic tissue (p > 0.05). It was concluded that TENS did not influence the tumor growth of 4T1 carcinoma
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Harbourne, Bryant Thomas. "Effect of hypoxia-inducible secreted protein, tenascin c, on 4T1 tumour cells in vitro and in vivo." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/45992.
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Introduction: Metastatic cancer is responsible for 90% of cancer related deaths. Past research focused mainly on the primary tumour, leaving the process of metastasis poorly understood.
Poorly oxygenated (hypoxic) tumour cells express hypoxia inducible proteins and have a more aggressive and invasive phenotype correlated with poorer prognosis. Hypoxic tumour cells are responsible for increased angiogenesis, invasion, matrix deposition and remodelling along with many other functions.
We hypothesize hypoxic tumour secreted proteins are responsible for promoting metastasis. Our aim is to identify these hypoxia inducible secreted proteins and determine mechanisms promoting metastasis.
Methods: Mammary carcinoma cells (4T1 – metastatic and 67NR – non-metastatic) were placed in 1% O₂ (hypoxic) or 21% O₂ (normoxic) for 24 hours. Stable Isotope Labelling of Amino acids in Cell culture (SILAC) and mass spectrometry were used to perform a quantitative proteomic screen of conditioned medium. Proteins in 4T1 conditioned media, up-regulated in hypoxia and absent from the 67NR results represented candidate secreted proteins in metastasis.
Tenascin C (TNC), a candidate protein identified from the proteomic screen was stably knocked down and over-expressed. In vitro, the Boyden chamber and wound healing assay were used to study invasion and migration. In vivo, metastasis was assessed using flow cytometry-based quantification of metastasized tumour cells in the murine lungs.
Results: (TNC) was identified as a secreted protein with a role promoting metastasis in vivo through enhanced migratory ability. In vitro, knockdown of TNC in 4T1 enhanced migratory ability whereas over-expression decreased migratory ability. These results were contradictory to the expected results based on the hypothesized in vivo role. However, in vivo knockdown of TNC in 4T1 tumour cells resulted in a significant decrease in lung metastases. These results are consistent with the expected role of TNC in vivo.
Conclusions: Despite the contradictory results in vitro, TNC had a positive metastatic role potentially through a migratory mechanism. TNC represents a potential new therapeutic drug target.
Given the 4T1 cell line results, these data support further examination of the migratory role of TNC and how it promotes metastasis. In addition, TNC expression in other tumour cell lines including human breast cancer should be examined.
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Silva, Renata Carvalho. "Fototoxicidade de nanoemulsão de extrato de crajiru (Arrabidaea chica) em linhagem de células de adenocarcinoma mamário murino (4T1)." reponame:Repositório Institucional da UnB, 2013. http://repositorio.unb.br/handle/10482/15126.
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Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-graduação em Biologia Animal, 2013.Submitted by Albânia Cézar de Melo (albania@bce.unb.br) on 2014-02-10T14:20:34Z No. of bitstreams: 1 2013_RenataCarvalhoSilva.pdf: 4451431 bytes, checksum: 1ab1cd7ef589f2e5dc5061124ef5ae6b (MD5)
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A terapia fotodinâmica (TFD) é uma terapia alternativa a cura de diversas doenças, entre elas o câncer. Um novo conjunto de fármacos fotossensibilizantes (FS) de origem natural oriunda de extratos e óleos vegetais tem sido testado na terapia contra o câncer. Porém, a maioria desses fármacos FS apresentam alguns entraves para uso clínico e nesse contexto, as nanoemulsões poliméricas, sistemas cineticamente estáveis, apresentam diversas potencialidades como sistemas carreadores de fármacos. O objetivo do presente estudo foi identificar e avaliar as possíveis propriedades fotoquímicas e fotofísicas do extrato clorofórmico de partes aéreas de crajiru (Arrabidaea chica) livre (ECr) e incorporado em nanoemulsão polimérica (NanoECr) e testar os efeitos da nanoemulsão na TFD contra células de adenocarcinoma mamário murino (4T1) in vitro. Por análises no espectrofotômetro, tanto o ECr quanto a NanoECr apresentaram absorbância em comprimento de onda de 670 nm e fluorescência em 690 nm e apresentaram produção de espécies reativas de oxigênio pelo teste de decaimento da absorbância do benzofurano, características fundamentais para serem considerados fármacos úteis em TFD. Pela técnica de espalhamento dinâmico da luz, a NanoECr apresentou diâmetro hidrodinâmico médio de 370,5 ± 264,31 nm, PdI de 0,133 ± 0,01 e carga de superfície de – 36,1 ± 0,15 mV, características que predizem que a formulação é estável. Nas microscopias eletrônicas de transmissão (MET) e varredura (MEV), as NanoECr apresentaram morfologia esférica e superfície rugosa com diâmetros médios de 374 ± 117 nm (MET) e 367 ± 69 nm (MEV antes da metalização) e 488 ± 70 nm (após metalização), sendo a MEV sem metalização o protocolo adequado para caracterização morfométrica dessas nanoestruturas. Após incubação da linhagem celular 4T1 com a NanoECr em várias concentrações na ausência de irradiação, foi determinada, por MTT, a concentração não tóxica (54 µg/mL) e em seguida, por espectrofotômetro e microscopia confocal o tempo máximo de interação da NanoECr com a linhagem 4T1 (15 minutos). Associando 54 µg/mL de NanoECr, por 15 min com irradiação com laser de comprimento de onda de 670 nm, morte celular ocorreu quando as células foram 2 2irradiadas com doses de energia variando entre 8,57 J/cm a 85,7 J/cm, e apenas na 2dose de energia de 85,7 J/cm (maior dose de energia utilizada no experimento) ocorreu 100% de morte celular. Na avaliação do tipo de morte celular, as células 2irradiadas em doses de energia de 25,7 J/cm apresentaram morte por apoptose, visualizada em microscopia confocal pela intensa marcação em laranja de corpos apoptóticos (laranja de acridina) e pela visualização de blebs e danos a mitocôndrias e 2retículo endoplasmático observados em MET. Já na dose de 85,7 J/cm, a necrose foi o tipo de celular ocorrido, observado pela intensa marcação do citoplasma das células em vermelho (brometo de etídeo) em microscopia confocal e por danos a membrana plasmática com extravasamento de conteúdo celular e presença de vacúolos no interior das células observadas em MET. Concluiu-se que o extrato clorofórmico de partes aéreas do crajiru incorporado em nanoemulsões poliméricas de PVM/MA é uma potencial formulação fotossensibilizante para uso em TFD. Além disso, as características desta preparação oferecem a perspectiva de que esta possa ser utilizada como um fotossensibilizante de 3ª geração na TFD. ______________________________________________________________________________ ABSTRACT
Photodynamic therapy (PDT) is an alternative therapy to cure a lot of diseases, including cancer. A new set of photosensitizing (PS) drugs arising from natural plants, as vegetable oils and extracts have been tested in cancer therapy. However, most of these PS drugs present some difficulties for clinical use and in this context, polymeric nanoemulsions, kinetically stable systems, have several potential as drug carrier systems. The aim of this study was to identify and evaluate possible photochemical and photophysical properties of the chloroform extract of aerial parts of crajiru (Arrabidaea chica) free (ECR ) and incorporated in polymeric nanoemulsion (NanoECr) and test the effects of this nanoemulsion in PDT against murine mammary adenocarcinoma cells ( 4T1 ) in vitro. By spectrophotometer analysis in both the ECr and NanoECr showed absorbance at a wavelength of 670 nm and fluorescence at 690 nm and production of reactive oxygen species by the decay of the absorbance of the test benzofuran, key features to be considered useful drugs in PDT. At the technique of dynamic light scattering, the NanoECr had an average hydrodynamic diameter of 370.5 ± 264.31 nm , PdI of 0.133 ± 0.01 and surface charge of - 36.1 ± 0.15 mV , characteristics that predict the formulation is stable. At transmission electron microscopy (TEM) and scanning electron microscopy (SEM), the NanoECr showed spherical morphology and a rough surface with an average diameter of 374 ± 117 nm (TEM), 367 ± 69 nm (SEM before etallization) and 488 ± 70 nm (SEM after metallization). The SEM without metallization was the most suitable protocol for morphometric characterization of these nanostructures. After incubation of 4T1 cell line with various NanoECr concentrations in the absence of irradiation, non-toxic concentration (54 µg/mL) was determined by MTT and then by confocal microscopy and spectrophotometer the maximum time of interaction between NanoECr and 4T1 line (15 minutes) was also determined. Associating 54 µg/mL of NanoECr for 15 min and irradiating the cells with a laser of 670 nm wavelength, cell death occurred when 2 2the cells were irradiated with energy ranging from 8.57 J/cm to 85.7 J/cm and only on 2the energy dose of 85.7 J/cm (higher dose of energy used in the experiment) occurred 100 % of cell death. Evaluating the type of cell death, cells irradiated at a energy dose 2of 25.7 J/cm had death by apoptosis, visualized by intense cytoplasmic stainning of the apoptotic bodies with acridine orange in confocal microscopy and a visualization of blebs and mitochondria and endoplasmic reticulum damage observed in TEM. At a 2,energy dose of 85.7 J/cm necrosis was the type of cellular occurred noted by intense staining of cells cytoplasm in red (ethidium bromide) in confocal microscopy and cell membrane damage with leakage of cellular contents and presence of vacuoles inside the cells observed in TEM. We can conclude that the chloroform extract of the aerial parts of crajiru incorporated in polymeric nanoemulsions is a potential photosensitizer formulation for use in PDT. Furthermore, the characteristics of this formulation offer the prospect that it can be used as a 3rd generation photosensitizer in PDT.
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Wu, Rita Shiu-fung. "Effects of B7.1, IFN-gamma, and antisense TGF-beta gene transfer on the tumorigenicity of murine 4T1 metastatic mammary carcinoma cells." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/280475.
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Cancer progression is attributed in part to immune evasion strategies that include lack of co-stimulation, down-regulation of cell surface MHC molecules, and secretion of immunosuppressive factors such as transforming growth factor-β (TGF-β). Gene therapy has been employed to counter these mechanisms of immune evasion by transference of B7.1, IFN-γ or antisense TGF-β genes into tumor cells resulting in cell surface expression of B7.1, upregulation of MHC class I and class II molecules, or elimination tumor-derived TGF-β, respectively. Although each of these transgenes has been shown to alter tumorigenicity in murine models, a direct comparison of their efficacy has not been performed. To compare the effectiveness of these transgenes in eliciting an anti-tumor response, a very aggressive, poorly immunogenic and highly metastatic mammary tumor cell line 4T1, was genetically modified to express B7.1, IFN-γ and antisense TGF-β transgenes. Both IFN-γ and antisense TGF-β gene expression significantly reduced the tumorigenicity of these cells compared to mock transduced cells, with IFN-γ having a greater effect. In contrast, B7.1 gene transfer did not affect the tumorigenicity of 4T1 cells. The anti-tumor response directed against antisense TGF-β-expressing 4T1 tumors was mediated by CD4+ and CD8+ T cells. However, CD8+ T cells and not CD4+ T cells, appeared to mediate the anti-tumor response against IFN-γ-expressing tumors. Treatment of tumor-bearing animals with IFN-γ or antisense TGF-β gene-modified tumor cell vaccines reduced the number of clonogenic metastases to the lungs and liver compared to treatment with mock-transduced cells. Finally, in a residual disease model in which the primary tumor was excised and mice were vaccinated with irradiated tumor cells, treatment of mice with vaccinations consisting of 4T1 cells expressing both antisense TGF-β and IFN-γ genes was the most effective in prolonging survival.
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Toccas, Salas Mary Luz. "Estudio del efecto del fucoidan de Lessonia trabeculata nativa (alga parda) sobre la capacidad migratoria y clonogénica de la línea celular de carcinoma mamario murino 4T1." Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2020. https://hdl.handle.net/20.500.12672/13998.
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El fucoidan es un polisacárido sulfatado presente en las algas pardas, cuya estructura y
composición varía entre las diferentes especies de algas y se ha demostrado que posee
efectos anticancerígenos, entre otros. El objetivo del presente estudio fue evaluar el
efecto del fucoidan de Lessonia trabeculata (FLt) sobre la capacidad migratoria y
clonogénica de la línea celular de carcinoma mamario murino 4T1. Se determinó la
citotoxicidad de FLt mediante el ensayo MTT; se calculó la IC50 (concentración que
inhibe el 50% de la población) y el índice de selectividad (IS). Como controles de
actividad se consideraron el estándar de fucoidan de Fucus vesiculosus (FFv) y el
quimioterápico doxorrubicina (Dox). Las células VERO-76 fueron empleadas como
control de células normales. Se realizó el ensayo de migración celular por el método de
“cierre de herida” y el ensayo clonogénico considerando 3 concentraciones de FLt,
seleccionadas a partir de su IC50. Los resultados muestran que el FLt redujo la viabilidad
celular de 4T1, con una IC50 de 950 µg/mL, y ejerció menor toxicidad sobre VERO-76,
demostrando toxicidad selectiva sobre 4T1 (IS= 3.15). El FFv ejerció menor efecto
citotóxico sobre ambas líneas celulares. El FLt inhibió significativamente y de manera
dosis-dependiente la migración celular y la capacidad clonogénica o formación de
colonias de 4T1 en concentraciones de 700, 950 (IC50) y 1200 µg/mL respecto al control
no tratado (p<0.0001) a las 12 y 24 h de exposición. Adicionalmente se consideró el
tratamiento combinado [Dox + FLt] IC50, demostrándose que el FLt IC50 incrementa la
efectividad de doxorrubicina sobre 4T1. Se concluye que el FLt tiene el potencial de
inhibir la proliferación, migración y capacidad clonogénica de 4T1 in vitro de manera
selectiva y dosis-dependiente.Perú. Consejo Nacional de Ciencia y Tecnología. Fondo Nacional de Desarrollo Científico y Tecnológico (Fondecyt). Proyecto de Investigación Básica. N° 133-2017
Tesis
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Schworm, Iris Noemi [Verfasser], Gabriele [Akademischer Betreuer] [Gutachter] Multhoff, and Stephanie E. [Gutachter] Combs. "Einfluss von Bestrahlung und operativer Resektion des Primärtumors auf extramedulläre Hämatopoese in der Leber anhand eines orthotopen 4T1 Mammakarzinom Mausmodells / Iris Noemi Schworm ; Gutachter: Stephanie E. Combs, Gabriele Multhoff ; Betreuer: Gabriele Multhoff." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1147968047/34.
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Blaudeau, Philippe. "Alexandrie et Constantinople : 451-491 : de l'histoire à la géo-ecclésiologie /." Rome : [Paris] : École française de Rome ; [diff. de Boccard], 2006. http://catalogue.bnf.fr/ark:/12148/cb40204357k.
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Topolansky, Barbe Frederico. "MERCOSUR Union, Porter's diamond and the competitiveness of the Uruguayan broiler industry." Thesis, University of Gloucestershire, 2008. http://eprints.glos.ac.uk/3174/.
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This study focuses on the analysis and assessment of competitiveness within the Uruguayan broiler industry. Porter's (1990) 'national diamond' was selected as the appropriate framework for analysis and was applied to the six major Uruguayan broiler firms. This research reveals that the unique characteristics of the Uruguayan broiler industry are successfully accommodated within the selected framework to explain the success of the broiler industry against other meat substitutes. Therefore, this study has confirmed Porter's (1990) diamond system as an adequate conceptualization of success in the Uruguayan broiler industry. These results are consistent with those found in the existing literature, lending support to the view that Porter's (1990) model seems to be applicable to developing countries such as Uruguay. However, some modifications of the model are required to fully explain the progress of this industry. This research project presents an adaptation of Porter's (1990) 'diamond' to the singularities of the firms investigated in this study. This study opted for an industry-level case study research strategy that is operationalized through in-depth personal interviews with owner directors and managers in six of the seven possible organizations within Uruguay. This is augmented by further data collection (additional interviews) through sources in government and market relevant bodies in order to generate information on the national context. The selected research method showed its utility for the investigation of weaknesses and strengths within the Uruguayan broiler industry. These findings were used to accomplish the second objective of this research which was to elaborate policy recommendations out of the primary and secondary collected data that would help Uruguayan broiler firms to compete with international broiler firms in a regional economic block (MERCOSUR) without barriers.
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Suciu, Diana J. "NEURAL ACTIVITY WITHIN SOLID BREAST TUMORS AND THE IMPLICATIONS ON METASTASIS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1528117273992639.
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Alkhatib, Suehyb. "Characterizing the role of Nucleosome Remodeling Factor (NURF) in tumorigenesis and metastatic progression using mouse models of breast cancer." VCU Scholars Compass, 2012. http://scholarscompass.vcu.edu/etd/376.
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Increasingly the role of epigenetic machinery as a bridge between underlying DNA sequence and cellular phenotype is being discovered. The establishment of a myriad of unique cellular types sharing identical gene sequences in a multicellular organism gives a broad sense for the inherent role of epigenetic influence on cell differentiation. Importantly, the epigenetic mechanisms involved in establishing cell identity unsurprisingly contribute to diseased states, including cancer. Recent research continues to elucidate contributory roles of epigenetic mechanisms, such as DNA methylation, histone modification, and microRNA regulation, in human cancers. Additionally, chromatin remodelers, such as the Nucleosome Remodeling Factor (NURF), have been identified as important regulators for normal cell biology. While much has been done to identify and characterize the role of NURF chromatin remodeling complex as a key regulator of development in a number of model organisms, little has been published on the implications of NURF in diseases such as cancer. Our preliminary data shows dysregulation of E-cadherins, N-cadherins, and MHC-I genes in Bptf (an essential subunit of NURF) knocked down murine breast cancer cell lines. These proteins have well documented roles in the development and metastatic progression of cancers. To study the effect of Bptf knockdown on the development and progression of cancer we injected Bptf knocked down mouse breast cancer cell lines, 4T1, 66cl4, and 67NR, into syngenic BALB/c mice. Our findings reveal decreased tumor growth in 66cl4 and 67NR as measured by tumor weight at 3-4 weeks post injection. Tumor growth did not appear to be significantly affected in 4T1 challenged mice. However, mice inoculated with Bptf knockdown 4T1 cell lines have decreased metastasis to lungs as compared to control while metastasis of 66cl4 tumors to the lungs appear unaffected. To assess the role of the immune system in decreasing tumor growth in BALB/c mice, we injected 66cl4 tumors into NOD-SCID-Gamma (NSG) immune deficient mice. The tumors from these mice show no difference in tumor growth between Bptf knockdown and control tumors, implicating a role for the immune system regulating the decreased tumor weight in BALB/c mice. To delineate which immune cell effector may impede breast cancer carcinogenesis, we performed an in vitro natural killer (NK) cell cytotoxicity assay against 66cl4 tumors and found greater susceptibility to NK killing in Bptf knockdown tumors.
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Meyer, Anthony Lee Isaac. "Determining the Significance of Alliance Pathologies in BipolarSystems: A Case of the Peloponnesian War from 431-421 BCE." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1464219367.
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Cavett-Dunsby, Esther Caroline. "Mozart's variations reconsidered: four case studies (K.613, K.501, and the finales of K.421 (417b), and K.491)." Thesis, King's College London (University of London), 1985. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.744784.
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Erdeniz, Burak. "Probability Learning In Normal And Parkinson Subjects: The Effect Of Reward, Context, And Uncertainty." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608877/index.pdf.
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In this thesis, the learning of probabilistic relationships between stimulus-action pairs is investigated under the probability learning paradigm. The effect of reward is investigated in the first three experiments. Additionally, the effect of context and uncertainty is investigated in the second and third experiments, respectively. The fourth experiment is the replication of the second experiment with a group of Parkinson patients where the effect of dopamine medication on probability learning is studied. In Experiment 1, we replicate the classical probability learning task by comparing monetary and non-monetary reward feedback. Probability learning behavior is observed in both monetary and non-monetary rewarding feedback conditions. However, no significant difference between the monetary and non-monetary feedback conditions is observed. In Experiment 2, a variation of the probability learning task which includes irrelevant contextual information is applied. Probability learning behavior is observed, and a significant effect is found between monetary and non-monetary feedback conditions. In Experiment 3a probability learning task similar to that in Experiment 2 is applied, however, in this experiment, stimulus included relevant contextual information. As expected, due to the utilization of the relevant contextual information from the start of the experiment, no significant effect is found for probability learning behavior. The effect of uncertainty observed in this experiment is a replication of the reports in literature. Experiment 4 is identical to Experiment 2
except that the subject population is a group of dopamine medicated Parkinson patients and a group of age matched controls. This experiment is introduced to test the suggestions in the literature regarding the enhancement effect of dopamine medication in probability learning based on positive feedback conditions. In Experiment 4, probability learning behavior is observed in both groups, but the difference in learning performance between Parkinson patients and controls was not significant, probably due to the low number of subject recruited in the experiment. In addition to these investigations, learning mechanisms are also examined in Experiments 1 and 4. Our results indicate that subjects initially search for patterns which lead to probability learning. At the end of Experiments 1 and 4, upon learning the winning frequencies, subjects change their behavior and demonstrate maximization behavior, which makes them prefer continuously one option over the other.
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Gozenman, Filiz. "Interaction Of Probability Learning And Working Memory." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614535/index.pdf.
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Probability learning is the ability to establish a relationship between stimulus and outcomes based on occurrence probabilities using repetitive feedbacks. Participants learn the task according to the cue-outcome relationship, and try to gain in depth understanding of this relationship throughout the experiment. While learning is at the highest level, people rely on their working memory. In this study 20 participants were presented a probability learning task, and their prefrontal cortex activity was measured with functional Near-Infrared Spectroscopy. It was hypothesized that as participants gain more knowledge of the probabilities they will learn cue-outcome relationships and therefore rely less on their working memory. Therefore as learning precedes a drop in the fNIRS signal is expected. We obtained results confirming our hypothesis: Significant negative correlation between dorsolateral prefrontal cortex activity and learning was found. Similarly, response time also decreased through the task, indicating that as learning precedes participants made decisions faster. Participants used either the frequency matching or the maximization strategy in order to solve the task in which they had to decide whether the blue or the red color was winning. When they use the frequency matching strategy they chose blue at the rate of winning for the blue choice. When they use the maximization strategy they chosed blue almost always. Our task was designed such that the frequency for blue to win was 80%. We had hypothesized that the people in frequency matching and maximization groups would show working memory differences which could be observed from the fNIRS signal. However, we were unable to detect this type of behavioral difference in the fNIRS signal. Overall, our study showed the relationship between probability learning and working memory as depicted by brain activity in the dorsolateral prefrontal cortex which widely known as the central executive component of working memory.
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Moore, Douglas C. "Fahrenheit 451: Tempreture Rising." Cleveland State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=csu1282686419.
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Al-Anizy, Mohammed. "Studies on cytochrome P450 4X1." Thesis, University of Nottingham, 2005. http://eprints.nottingham.ac.uk/10404/.
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Antisera raised against recombinant human CYP4Z1 (4Z1), mouse Aryl hydrocarbon receptor (AhR), and C.elegans Latrophilin (LpH) proteins were titred over the course of several bleeds. The sensitivity of the antibodies shows an increase over the course of several immunizations, with the minimum amount detected being 1 ng of 4Z1, 0.3 ng of AhR, and 0.3 ng of LpH. Terminal bleeds were taken for the AhR and LpH antisera. The AhR antisera detects proteins in rat and mouse liver cytosol consistent with previous reports of the AhR. LpH is predicted to be localized in a membrane compartment on the basis of its primary structure, so sub-cellular fractions of C.elegans were isolated and tested, revealing a protein of ~113 kDa in a crude membrane preparation. This protein was not solubilized in < 1% Emulgen 913, but was soluble in 2% dodecylmaltoside. A fresh 15k supernatant treated with 2% dodecylmaltoside showed a strong band of LpH protein at ~113 kDa. However, 66 kDa band was detected when the samples were stored overnight at 4 degrees centigrade due to presence of a G protein coupled receptor proteolysis site (GPS) between position M536 and C547 of LpH, which is a characteristic feature in the LpH protein family. In order to study the expression of the CYP 4X1 in mouse tissues, RNase protection assays were performed. Different tissues were assayed at the same time and the same riboprobe was used to hybridise all the samples. The CYP 4\x1 probe was shown to be full length (-ve control). However, the +ve control (RNase positive) shows an absence of signal when hybridised to the yeast tRNA demonstrating the specificity of the signal in the samples. Several RNA samples were hybridised with mouse cyp4X1 gene probe, such as aorta, brain and heart and liver. The mouse cyp4X1 gene appears to have 12 exon from the genomic sequence and encodes a protein which high identity with the human and rat cyp4X1 gene. The full-length of the probe was 424 b.p and the protected fragments were 177 b.p. The murine cyp4X1 was not expressed in control liver, but is expressed in brain at high level. Cyp4X1 gene was also investigated in aorta tissue and found to be expressed at low levels. Known inducers of hepatic cytochrome P450 were used (Ciprofibrate, TCDD, PB, and dexamethasone), but had no induction effect in the samples. Western blotting of brain confirmed that the cyp4X1 protein is expressed in brain, and quantification showed that this is a major cytochrome P450 in brain.
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Cruz, Pizarro Kike Rubén, Quevedo Sebastián Ricardo León, Apari Edinson Manuel Fernandez, Chavez Edgardo Mijael Ayala, and Cuadros Cindi Janet Barboza. "Mobiliario multifuncional Winner Space 4.1." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2018. http://hdl.handle.net/10757/625377.
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Actualmente las personas quieren moverse menos y en lugares que tengan conectividad para tener cerca el trabajo con la vivienda, también busca una vida más urbana, que mezcle la vida privada y profesional cerca. Todos estos detalles hacen que la tendencia es adquirir viviendas pequeñas, cuyas características enfrentan a los problemas ya mencionados. Las personas se saturan y hasta se estresan por el poco espacio que les queda cuando están en casa, ya que ante una reunión familiar u otro no permitiría el desenvolvimiento de las personas.
Una solución para este problema es optimizar su espacio en el hogar para lo cual se propone tener un mobiliario con 4 funciones que ayudaría el desenvolvimiento en el hogar ¿Cómo será esto? Es fácil, se crea Winner Space 4.1, un mobiliario que se comportará como mesa, banco, planchador y cuadro. Fácil de adquirir en nuestro punto de venta de una manera fácil, rápida, y recibirlos en su hogar por servicio de delivery.
Para crear nuestro proyecto, se realizó un análisis de mercado, el cual nos permitió enfocarnos en Lima Norte, sector que sigue creciendo comercialmente en los últimos años por la oferta de viviendas pequeñas.
Con la finalidad de ingresar al mercado, se realizarán campañas de marketing de enfoque, contando con publicidad en vallas y redes sociales. También, contaremos con un plan de operaciones, el cual nos garantizará la producción del producto deseado. Esto nos permitirá seguir abarcando otros distritos del cono norte para incrementar nuestra rentabilidad.Currently people want to connect less than in places that have connectivity to have close work with housing, also looking for a more urban life, which mix private and professional life nearby. All these details make the trend turn into small houses. People are saturated and even stressed by the little space left when they are at home, and that they are in a family meeting. A solution for this problem is to optimize your space in the home for what is proposed to have a furniture with 4 functions that help the development in the home. How will this be? It's easy, Winner Space 4.1 is created, a furniture that behaves like a table, bench, ironing board and table. Easy to acquire at our point of sale in an easy, fast way, and receive in your home by delivery service. To create our project, a market analysis is carried out, which allows us to focus on Lima Norte, the sector that continues to grow commercially in recent years due to the supply of small homes. In order to enter the market, focus marketing campaigns are carried out, with advertising on billboards and social networks. Also, have an operations plan, which guarantees the production of the desired product. This allows us to follow other districts of the north cone to increase our profitability.
Trabajo de investigación
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Holt, Jim, and D. K. Herring. "Mitral Valve Prolapse, 4th Revision." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/6473.
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Jardim, Guilherme Tanger. "A tutela antecipada nos artigos 273, 461 e 461-A, do Código de Processo Civil." Pontifícia Universidade Católica do Rio Grande do Sul, 2008. http://hdl.handle.net/10923/2419.
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Previous issue date: 2008Questo lavoro ha per finalità trattare l´istituto dei provvedimenti d'urgenza degli articoli 273, 461 e 461-A dei Codice di Procedura Civile. Per tanto, sarà realizzata investigazione storica del riferito istituto partendo del dirittto romano antico Ed arrivando fino al diritto processuale odierno. Prima di entrare nel cuore della questione saranno sviluppati temi essenziali per la comprensione del istituto come la giurisdizione i provvedimenti d'urgenza. Da allora, sarà sviluppato modalità di provvedimenti d'urgenza. In questo esame, verrà esaminato il fabbisogno di ciascuna delle modalità, così come loro caratteristice intrinsece. Insomma, come un comune punto tra i provvedimenti d'urgenza, sarà ricerche la fungibilità tra i provvedimenti d'urgenza, la particolarità procedurali e l'esame del diritto comparato, prendendo il diritto italiano come paradigma. ita
Este trabalho tem por finalidade apresentar uma perspectiva sistemática da tutela antecipada nos artigos 273, 461 e 461-A, todos do Código de Processo Civil. Para tanto, se estudarão, inicialmente, as raízes do instituto a partir do direito romano antigo até o direito processual brasileiro vigente. Antes de adentrar no cerne da questão serão desenvolvidos temas essenciais para a compreensão do instituto tais como, a jurisdição e as tutelas de urgência. A partir de então, serão desenvolvidas as modalidades da antecipação de tutela. Nesse exame, serão investigados os requisitos de cada uma das modalidades, bem como suas peculiaridades. Por fim, como ponto comum entre as tutelas antecipadas, se pesquisará a fungibilidade entre as tutelas de urgência, as particularidades procedimentais da tutela antecipada e o exame de direito comparado, tomando o direito processual italiano como paradigma.
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Ioannou, Christos. "The importance of predator behaviour on risk to prey." Thesis, University of Leeds, 2008. http://etheses.whiterose.ac.uk/275/.
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Both predator and prey have evolved to maximise reproductive success by balancing food intake with risk. There has been a bias in predator-prey studies, where prey behaviour has been examined in detail, yet predators are assumed to follow simplistic rules. I use three-spined sticklebacks predating upon invertebrate prey to test a range of ways in which prey risk was hypothesised to be affected by predator behaviour. The relationship between encounter rate and prey density has been recently shown not to be directly proportional, and theoretical arguments have been made that predator search behaviour can explain this trend. I test these arguments, and show acceleration of a predator's search path can in fact lead to the observed less-than-directly proportional relationship between prey density and encounter rate. The perceptual constraints of predators can have major impacts on prey risk. Once encountered, an attack was more likely when prey were encountered late in a search, probably due to a decrease in anti-predator vigilance as the fish became more habituated to the arena. In a subsequent study, larger groups of prey were more quickly found, as were larger numbers of groups. This led to the conclusion that the field of attention is a subset of the total visual field, and this is also supported by denser prey being more conspicuous. Although the predator responded to increased prey group size and density with a reduced time to detect and attack prey, attacks on such groups were less successful due to the confusion effect. Interestingly, I show the effect of prey density to be sensitive to spatial scale, where a large-scale measure of density affected conspicuousness and a small-scale measure affected attack success. This was explained by a reduction in the total number of prey in the visual field as a group of prey is approached and attacked. In the final chapter, I turn my attention to differences in temperament within a predator population, and how this affects prey risk. As expected, bolder fish represented a greater risk to the prey. However, as larger fish tended to be more bold, suggesting boldness was driven by their perception of predation risk, a within community behaviourally-mediated trophic cascade may occur. where the risk to prey is driven by their predators' own perceived risk of predation. This shows that optimal foraging decisions under the threat of predation, as well as perceptual constraints, can mediate the effect of predator behaviour on prey risk.
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Salomao, Nadia Maria Ribeiro. "Interaction between mothers and children with specific language impairment: a longitudinal study." Thesis, University of Manchester, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576095.
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The present longitudinal study was designed to provide a description of the changes that occur across time in three mother-child with SLI dyads in conversational interaction. Analysis of the mother-child with SLI conversations included: a) a structural analysis- mean length of utterance (MLU) , mean number of utterances per turn and number of non-verbal turns for the mother and child. b) a contingency analysis, a functional analysis of mother-child interactions, and a child's conversational participation analysis. Each dyad is discussed, initially, as a single case study. Comparisons between the dyads' conversational behaviours are made and set out in the second and third parts of the results' section. These comparisons are warranted by the fact that these children were selected because they were at the same stage of language development at the beginning of the study. The analysis of the results indicated individual differences in the children's conversational participation. Nonetheless, for all three children and for all observational sessions, participation in the conversation was considered mainly adequate in relation to the mother's previous utterance. The highest proportion of maternal contingent replies were, for the three dyads and across all observational sessions, topic continuations. That is, independent of age and language level the mothers provided continuation to the current topic of conversation of the dyad. The results are evaluated in terms of methodological aspects of longitudinal studies with mother-child with SLI interaction. Some clinical implications are also discussed.
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Philburn, Elke. "A laryngographic study of German stop glottalisation." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.495750.
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Tins study investigates the occurrence and the production of glottalised stops in German. While the occurrence of voiced, voiceless and aspirated stops in German is well documented, glottalised stops have received limited attention in the literature. The study starts by reviewing previous phonetic and phonological accounts of stop glottalisation in German as well as related phenomena in other lanmges. The focus lies on recent phonetic investigations which represent German stop glottalisation as a means of increasing articulatory ease, based on the assumption that under certain conditions, control of the velum during stop production may be limited.
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O'Halloran, Kieran. "Mystifying discourse : a critique of current assumptions and an alternative framework for analysis." Thesis, Ulster University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646855.
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Nethercott, Acer. "The semantics of complex demonstratives." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.650282.
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A demonstrative expression is a linguistic device for which, paradigmatically, an accompanying demonstration is required for the determination of content. It is through witnessing the demonstration that accompanies a stereotypical (i.e. deictic I) tokening of a sentence in which a demonstrative expression occurs that a listener discerns which object that demonstrative, on that occasion of use, is being used to talk about. The listener thereby grasps what was said (semantically; and often as a result, pragmatically) via the making of that utterance. Consequently, in the paradigmatic case to miss the demonstration accompanying the use of a demonstrative expression is to be left ignorant as to the referent of the expression on that occasion of use. To the extent that this is a correct categorisation of the paradigmatic case it is correct to say that a hearer will be unable to grasp fully what has been said via an utterance of a sentence containing a demonstrative unless that hearer has witnessed the accompanying demonstration, and thereby is aware which object is the demonstratum? Examples of such paradigmatic uses of demonstrative expreSSIOns are easy to construct. "That" in an utterance in the Louvre of "That is a beautiful painting" is one example (the accompanying pointing action needing to be witnessed in order to determine just which painting is being complimented). An accompanying demonstration is not always necessary, however. In some circumstances the context may do for the speaker or already have done that which the demonstrative act does in the paradigmatic case (viz. render one object in the conversational context relevantly salient). Kaplan's "Stop that man!" scenario is an example of this kind: .. . a demonstration may also be opportune and require no special action on the speaker's part, as when someone shouts "Stop that man" while only one man is rushing toward the door.
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Tominc, Ana. "Jamie Oliver as a promoter of a lifestyle : recontextualisation of a culinary discourse and the transformation of cookbooks in Slovenia." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.656864.
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This thesis examines the recontextualization and localization of global culinary discourse to Slovenia after its independence from Yugoslavia in 1991 and its transition into a free market economy. Slovenia and its emerging celebrity chefs, Luka and Valentina Novak, are an example of the' local', whereas the global is represented by the British celebrity chef Jamie Oliver. The study is based on culinary texts from Oliver and the Novaks' cookbooks. However, 'standard' Slovene cookbook texts are also analysed with the aim of showing the difference between the previous educational role of cookbooks and the contemporary, increasingly edutaining role of the new 'celebrity' cookbooks. This study is situated within critical discourse analysis and it generally draws on the methodological framework of the discourse-historical approach ('DHA') (Reisigl and Wodak 2001), but also combines this with theoretical insights from the dialecticrelational approach (Fairclough 2010, 1992, 2001 [1989]). Its underlying theoretical focus has been recontextualization, which is one of the salient concepts within 'CDA' (e.g. Wodak and Fairclough 2010; Chouliaraki . 1998). The model of recontextualization that I presented in this thesis (based on the definition of discourse in 'DHA') enables me to show how global culinary discourse has been recontextualised from Britain to Slovenia, via, firstly, a translation of Jamie Oliver's cookbooks, and secondly, via the production of an original local discourse. The main claim of this thesis is that under the influence of global culinary discourse, local representations related to food and taste change, and so do cookbooks as genres. Whiie recontextualization as translation results in appropriation of the text to the local circumstances in terms of genre conventions, branding opportunities, country-related representations (e.g. Italy) and the reconfirmation of the national identity, the second phase of recontextualisation reveals the characteristics of the locally produced discourse based on global characteristics. Compared to the 'standard' Slovene cookbooks, its 'celebrity' variant aims to reconstructs the national culinary identity via legitimation of the tastes ofthe new middle classes. Influenced by the global model, the Novaks' tend to represent food and foodstuffs relying on characteristics found in advertising while social actors are often synthetically personified (Fairclough 1989). Likewise, various perspectives construct a seemingly democratisized discourse and disperse the top-down authority as found in 'standard' cookbooks.
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Kalashnikova, Marina. "The mutual exclusivity assumption : a social-cognitive approach to its development and flexible use in lexical acquisition." Thesis, Lancaster University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658574.
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The Mutual Exclusivity (ME) assumption guides early lexical acquisition by biasing children to establish one-to-one relationships between word forms and their meanings. While it constitutes a useful strategy for word learning, ME is often suspended to allow for the acquisition of terms that overlap in reference. Furthermore, while extensive previous research has shown that children maintain ME by default, the developing ability to use it as a flexible assumption and its linguistic or cognitive nature remain debated. The present work introduces the social-cognitive framework to investigate the ontogeny of this strategy, its flexible use according to the context of each naming situation, and its relation to more general aspects of early linguistic, social, and cognitive development. A set of behavioural and preferential looking eye-tracking paradigms were constructed to assess the flexible use of ME in populations of 18-month-old infants, monolingual, sequential bilingual, and simultaneous bilingual three- to five-year-old children, and adults. The exclusivity paradigms tested participants' default use of the assumption, while the overlap paradigms tested their ability to suspend it to acquire referentially overlapping terms. In addition, children completed batteries of tasks of receptive vocabulary, social understanding, metalinguistic, and general cognitive development, which were analysed in relation to performance in the ME tasks.
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Thaisen, Jacob Ronnow. "Studies in the Orthography of Some Early Manuscripts of Chaucer's 'Canterbury tales'." Thesis, De Montfort University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502580.
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The systems of spelling found in the extant manuscripts of a late Middle English text are rarely considered in discussions of the transmission of that text. If they are, scholars have typically used the occurrence of dialectal spellings to allocate manuscripts to geographical areas or the occurrence of identical spellings, often unusual spellings, in corresponding locations across the manuscripts to recover the usage of the presumed archetype. The basis for much of this scholarship has been profiles which rely upon text samples or which list what spellings are found in a manuscript but do not reveal the internal distribution of these spellings in that manuscript. This study considers the spelling and codicology of nine complete, textuallyimportant manuscripts of Geoffrey Chaucer's Canterbury Tales, each of which was copied by a different scribe. The author semi-automatically indexes the electronic transcripts prepared by the Canterbury Tales Project from the spellings registered in the Project spelling databases for one of the tales. He extracts a comprehensive spelling profile for each manuscript from this index. The profiles correspond to the questionnaire used for Angus McIntosh, M.L. Samuels, et aI., A Linguistic Atlas of Late Mediaeval English (Aberdeen, 1986).
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Bianchi, Francesca. "Culture, corpora and semantics : methodological issues in using elicited and corpus data for cultural comparison." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.660111.
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The current work is a methodological investigation in the use of elicited data and Web data in the analysis of cultural specificities statting from semantic elements. After considering and discussing several theoretical and analytical approaches to culture in linguistics, anthropology, psychology, and marketing research, a specifically developed method of analysis and cross-cultural comparison is applied to elicited data on chocolate and wine, gathered through free sentence-completion and sentence-writing tests on English and Italian respondents. The results obtained are discussed within the framework of cultural systems theories and used as control reference for further methodological investigations. In palticular, the elicited data are qualitatively and quantitatively compared to non-elicited sentences on chocolate and wine from general Web corpora in English and Italian. Furthermore, in order to find an alternative route which could avoid the complex and time-consuming process of manually coding a large dataset, some alternative routes are tested, based on the creation of sub-corpora using sampling procedures and analysis of a limited number of the most frequent words in the dataset's wordlist. Finally, an automatic semantic tagger is tested on the elicited data, in order to assess the extent of its possible application in cultural analysis. Comparisons between the Web corpora and the elicited data suggest that large general Web corpora can be considered representative of the cultural associations of a node word and could thus be used in cultural analysis or in exploratory marketing research. Finally, in the light of the results of the various methodological tests, the work discusses general issues, such as the relationship between word frequency and cultural relevance, and tagset granularity.
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McGee, Iain David. "Lexical intuitions and collocation patterns in corpora." Thesis, Cardiff University, 2006. http://orca.cf.ac.uk/56062/.
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Language teachers are often called upon by their students to provide examples of vocabulary usage in the classroom. Drawing on their experience of language, these teachers model lexical combinations and collocations, not only in their classes, but also in materials writing. However, corpus linguists have claimed that native speaker intuitions about the typical collocates of words are not reliable, because they do not align with the patterns observed in large corpora. These claims are critically evaluated, and an alternative explanation for the mismatch, the possibility that the corpora might not be representative of actual language in use, is also examined. Various linguistic and psycholinguistic explanations for the disparity between corpus data and elicited data are examined, and theories dealing with the mental representation of collocations are also discussed. Data from word frequency estimate research, and word association research are also analysed for relevant information on the subject. Five experiments are then reported, investigating the ability of native speakers (students and EFL teachers) and non- native speakers (Arab university teachers) to rank, recognize and spontaneously produce frequent adjective-noun collocations. The results indicate that a key factor affecting the 'quality' of lexical intuitions may be the employment of an 'availability heuristic' in judgements of frequency. It is argued that some collocates of words may be more hidden from memory searches than others, and that there may be a systematic bias in the respondants' lexical intuitions based on how words are stored in the mental lexicon. Conclusions are drawn that reflect the many facets of research relevant to the questions under discussion: corpus linguistics, frequency theory, word association research, learning theory and theories of lexical storage. The thesis ends in applying some of the key findings to language teachers.
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Munyandamutsa, Jean Baptiste. "Study of the Rwandan learners' intelligibility in spoken English." Thesis, Cardiff University, 2005. http://orca.cf.ac.uk/55571/.
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The present study investigates the phonological productive and perceptual competence of a group of Rwandan learners of English and the effect that phonological deviations have on their intelligibility and comprehension in spoken English. In order to discover the hierarchy and degree of difficulty these subjects have in the segmental and suprasegmental features of English, productive and perceptual tests of words and sentences were designed and administered to a group of 60 subjects. The study also attempts to explain the effect of various interlanguage phenomena which occur in the production and perception of the pronunciation of English by Rwandan speakers. The results of this study support many of the claims of CA, EA and phonological interlanguage. Chapter One gives background sociolinguistic information on the roles of Kinyarwanda, French, Kiswahili and English in Rwanda. Chapter Two discusses a number of theoretical key issues involved in language learning and acquisition. Chapter Three defines the topic of the study, i.e. intelligibility and comprehension, to gain insight into the study and to provide a framework for the research design and methodology. Chapter Four is a description of the Kinyarwanda and English phonological systems, which is the basis of the predictions of the difficulties and the design of data for Chapters Five and Six. Chapter Five analyses, categorizes and explains the source of deviations in the data gathered from subjects' pronunciation of words and sentences as interpreted by native English speakers. Chapter Six analyzes the effect of phonological deviations on the subjects' comprehension of spoken English. Chapter Seven concludes the whole study with a discussion of the major findings, and suggests some useful steps towards more effective teaching of the pronunciation for better intelligibility and comprehension in English.
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Podhovnik, Edith. "The phonology of Neath English : a socio-dialectological survey." Thesis, Swansea University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.587852.
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The aim of this thesis is, first, to describe the phonetic and phonological features of Neath English, secondly, to discuss the possible effect of non-linguistic factors on people's choice of speech forms and, finally, to analyse the intonation of Neath English. Based on the data collected in fieldwork, the accent description gives the vowel and consonant phonemes and their realisations. Neath English, which is the English spoken in Neath, South Wales, is compared and contrasted to RP as well as other Southern Welsh English accents. To illustrate the similarities and differences to RP and Welsh, vowel and consonant typologies are given. Additionally, this thesis looks at how and to what extent the non-linguistic factors affect people in their choice of speech forms. A detailed computer analysis of the data gives insight into how age, male/female and education have influenced people's speech forms. Six groups of informants are compared to each other in order to discuss their different use of certain variables in their speech. In the description of Neath English intonation, the nuclear tones, the tones in heads and tails and the grammatical, attitudinal, and discourse functions of Neath English intonation are described. Neath English intonation is also compared to RP and other Southern Welsh English accents.
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Hassan, Batoul. "Ideology, identity, and linguistic capital : a sociolinguistic investigation of language shift among the Ajam of Kuwait." Thesis, University of Essex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502127.
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The purpose of this study is to explore the relationship between language practices and non-linguistic processes that affect the outcome of language shift and loss situations. The community under investigation form a small minority Kuwaiti-Persian ethnic group known as Ajam. The Ajam speak a distinct variety of Persian referred to as Eimi within a dominant Arabic speaking community. The language practices of Ajam are analysed within a language and political economy framework. Key notions such as capital, field, habitus, and symbolic domination (Bourdieu 1991) are used to understand not only why language shift has taken place, but also why Eimi is still used to some extent. To this end a combination of ethnographic methods and quantitative analysis was used to collect data from 140 questionnaires and 20 informal interviews. Analysis of the data shows that Eimi has limited linguistic capital that can be symbolically used as a marker of solidarity. However, the analysis also indicates that not only has Eiml been in a state of decline for some time but the use of Eimi has drastically declined among the youngest generation of Ajam. Essentially, Eimi does not function as a symbol of ethnic or religious identity. Furthermore, underlying the language shift process is the divergent language ideologies and attitudes towards Eimi and Arabic. Despite the expression of positive attitudes towards Eimi and the teaching of Eimi to future generations, negative ideologies in the form of the 'non-standard language' and negative effects of multilingualism' are the main catalyst in the language shift process. On the other hand, informants attached positive ideologies to Arabic as a symbol of Arab nationalism, as a divine language, and as a symbol of Kuwaiti identity. Through discussion of these findings this study contributes to the understanding of the relationship between language behavior, ideology, and identity in the face of language shift and loss.
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Bailey, Laura Rudall. "The syntax of question particles." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/1915.
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Cross-linguistically, languages are largely head initial or head final. Most permit some disharmony, but Holmberg (2000) and Biberauer, Holmberg & Roberts (2012), among others, have argued that the structure shown in (1) is ruled out, where YP is X’s complement and ZP is Y’s complement: (1) *[XP [YP Y ZP] X] In structures such as (1), a head-final phrase immediately dominates a head-initial phrase, violating the so-called ‘Final-Over-Final Constraint’ (FOFC). Descriptively however, final question particles are readily found in languages with VO order, resulting in a structure that appears to violate FOFC. (2) illustrates this violation in Tetun (an Austronesian language of East/West Timor), and (3) shows the structure, with a final question particle ka immediately dominating a head-initial TP: (2) ó la bá sekola ká? 2S not go school or (Said to child playing:) ‘Didn't you go to school?’ (Van Klinken 1999: 212) (3) iii If ka constitutes the C head of CP, as is standardly assumed, the structure in (3) violates FOFC. I show, following Aldridge (2011), that these particles are best analysed as disjunctive elements, heading an elided clause: (4) [ConjP CP [Conj CP]] The particle is the head of the phrase, with the second CP as its complement and the first (pronounced) CP in Spec,ConjP. This solves the FOFC problem because the ‘particle’ is not final, and therefore the derivation does not include a head-final phrase dominating a head-initial phrase. Instead, the particle precedes its complement (which is not pronounced), and the clause that it follows (which is pronounced) is its specifier. I provide evidence for this position through typological investigation and theoretical analysis. In addition, the various proposals that have been put forward in the literature to avoid this FOFC-violation are considered, but are shown to be problematic in different respects. I discuss the idea that particles are not heads (Biberauer, Holmberg & Roberts 2012). However, they cannot be specifiers and an adjunction analysis fails to explain their properties, so it is unclear what they could be if not heads. Julien (2001), Lee (2005, 2008) and Simpson & Wu (2002) argue that final particles are derived by TP-movement to a Topic or Focus position. This is a promising explanation, but fails to derive the difference between final particles and other types. If the particle is syncategorematic (Biberauer, Holmberg & Roberts 2012), the fact that they appear in fixed positions is mysterious. Processing explanations of the data (Hawkins 2004, Philip 2012) go some way towards deriving the FOFC facts but do not, among other things, explain the high number of final particles in VO languages. The syntax of question particles is discussed in detail, and it is proposed that polar questions consist of two functional heads in combination: Force, giving a (main clause) question illocutionary force, and Polarity, giving a (neutral) iv question open polarity. A true polar question particle is therefore related to one or both of these heads: (5) With this background, the argument is defended in subsequent chapters that some particles cannot be true question elements in this sense and are instead instantiations of the disjunction. Cross-linguistic data demonstrate that final particles in VO languages differ from other types of question particle (initial particles, or final particles in OV languages) in very rarely marking embedded questions: they do so in only one language in the corpus. Homophony between the question particle and disjunction in many languages, combined with attested grammaticalisation paths, adds support to this claim. Furthermore, this analysis explains a number of properties of such particles in addition to their propensity to violate FOFC, including their frequent absence from negative questions, alternative questions and wh-questions. All of these are straightforward consequences of the particle being a disjunction. Finally, the analysis is applied to a particular language, Thai, as a case study, and it is compared with languages of the other types. It is shown that the disjunctive analysis is best able to explain the data and offer an elegant explanation of the FOFC facts.
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Feng, Guangwu. "A theory of conventional implicature and pragmatic markers in Chinese." Thesis, University of Reading, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429233.
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Boughton, Zoë Collette. "Phonological variation in contemporary standard french : a tale of two cities." Thesis, University of Newcastle Upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401835.
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Takahashi, Toyomi. "Syllable theory without syllables." Thesis, University College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406644.
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Ilori, Taiwo Abosede. "Why am I learning dis language sef? : imagined community and language ideologies of English of senior secondary school students in Nigeria." Thesis, Anglia Ruskin University, 2016. http://arro.anglia.ac.uk/702186/.
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This study explores senior secondary school (SSS) students' imagined community and identities against the language ideologies of English portrayed in the discourse on education in Nigeria. There has been lots of research done in the areas of identity, imagined community and L2 teaching from different perspectives and contexts (Norton, 2000; Ilori, 2013, Sung, 2013). However, no studies have under a Critical Discourse Analysis (CDA) angle, explored how learners' identities /imagined community are constructed and what resources or mechanisms (e.g. language ideological discourses of English) play a role in the construction of their identities/imagined community. The research draws on Fairclough‘s (2001) concept of social discourse, van Dijk‘s (2006) socio-cognitive approach to CDA and Norton's (2000) notion of imagined community, and is designed around a qualitative study involving open-ended questionnaires and official documents (e.g. language policy on education). This questionnaire which facilitated the interview process of participants (students, parents, teachers and principals) was digitally recorded, transcribed, coded and analysed thematically. Findings suggest that the English language, more than any other language is implicated in the process of imagination, as the choices students make about who they are and who they want to be are direct responses to how English is perceived in the local (social, political and educational) and global context. Therefore, examining the relationship that may exist between the ideologies that associates English with the resource of education, employment or status and students‘ imagined communities/identities may demand that neutrality should no longer be accepted as a concept when talking about imagination or identity. In this way, learners would no longer be viewed as social beings with multiple identities that emerge within specific learning trajectories (Norton, 2000), but as beings with deep-rooted ambiguities that must be represented in a reasonable and justifiable way.
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Hayes, Sarah L. "The political discourse and material practice of technology enhanced learning." Thesis, Aston University, 2015. http://publications.aston.ac.uk/26694/.
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Technology discloses man’s mode of dealing with Nature, the process of production by which he sustains his life, and thereby also lays bare the mode of formation of his social relations, and of the mental conceptions that flow from them (Marx, 1990: 372) My thesis is a Sociological analysis of UK policy discourse for educational technology during the last 15 years. My framework is a dialogue between the Marxist-based critical social theory of Lieras and a corpus-based Critical Discourse Analysis (CDA) of UK policy for Technology Enhanced Learning (TEL) in higher education. Embedded in TEL is a presupposition: a deterministic assumption that technology has enhanced learning. This conceals a necessary debate that reminds us it is humans that design learning, not technology. By omitting people, TEL provides a vehicle for strong hierarchical or neoliberal, agendas to make simplified claims politically, in the name of technology. My research has two main aims: firstly, I share a replicable, mixed methodological approach for linguistic analysis of the political discourse of TEL. Quantitatively, I examine patterns in my corpus to question forms of ‘use’ around technology that structure a rigid basic argument which ‘enframes’ educational technology (Heidegger, 1977: 38). In a qualitative analysis of findings, I ask to what extent policy discourse evaluates technology in one way, to support a Knowledge Based Economy (KBE) in a political economy of neoliberalism (Jessop 2004, Fairclough 2006). If technology is commodified as an external enhancement, it is expected to provide an ‘exchange value’ for learners (Marx, 1867). I therefore examine more closely what is prioritised and devalued in these texts. Secondly, I disclose a form of austerity in the discourse where technology, as an abstract force, undertakes tasks usually ascribed to humans (Lieras, 1996, Brey, 2003:2). This risks desubjectivisation, loss of power and limits people’s relationships with technology and with each other. A view of technology in political discourse as complete without people closes possibilities for broader dialectical (Fairclough, 2001, 2007) and ‘convivial’ (Illich, 1973) understandings of the intimate, material practice of engaging with technology in education. In opening the ‘black box’ of TEL via CDA I reveal talking points that are otherwise concealed. This allows me as to be reflexive and self-critical through praxis, to confront my own assumptions about what the discourse conceals and what forms of resistance might be required. In so doing, I contribute to ongoing debates about networked learning, providing a context to explore educational technology as a technology, language and learning nexus.
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Bartlett, Tom. "The transgressions of wise men : structure, tension and agency in intercultural development discourse." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/24931.
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This thesis is based on fieldwork carried out in Guyana, South America, between 1999 and 2002, looking at the use of English in negotiating situations between the indigenous Makushi communities of the North Rupununi Savannah, the Government of Guyana, and non-governmental and international development organisations. It considers notions of liminality and third-space encounters as they relate to the evolution within the Discourse of Development of fora that temporarily accommodate both indigenous and external modes of discourse, so opening up for debate the ideologies behind them while fostering the interactive development of a third mode capable of expressing relevant aspects of both ideological systems simultaneously and so capable of expanding each individually. The need for such a hybrid space is placed in relation to the material situation of the Makushi people and wider socioeconomic and cultural issues of power, ideology and the limits of agency. The ongoing development of this space is illustrated through detailed analysis of linguistic interaction within the specific forum of the North Rupununi District Development Board. A theory is developed for relating micro and macro issues of discourse and power and a two-way relationship established between top-down pressures towards conformity and bottom-up processes of agentive change. This framework is then related to the current subordinate position of Makushi communities within Guyana and their existing achievements in developing hybrid discourses to challenge this situation. The thesis concludes with a consideration of possible applications within the existing development context in the North Rupununi, within international development in general, and within the education system.
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Hadjidemetriou, Chryso. "The consequences of language contact : Armenian and Maronite Arabic in contact with Cypriot Greek." Thesis, University of Essex, 2009. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502173.
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Al-Sulaihim, Nailah. "Phonological awareness and reading in monolingual and bilingual Kuwaiti children." Thesis, University of Reading, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.649269.
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A large body of research to date has focused on the link between phonological awareness (PA), emergent literacy, and reading success. The bulk of research on the relationship between PA and literacy has been conducted in monolingual children. It is unclear how this relationship presents in bilingual Arabic speaking children. The aim of the current study was to address the relationship between PA and literacy skills in monolingual Arabic-speaking and bilingual Arabic-English speaking Kuwaiti children who read in the Modern Standard Arabic (MSA) orthography. A cross-sectional and longitudinal design was used. Participants were four groups of children (monolingual kindergarten, bilingual kindergarten, monolingual first grade, and bilingual first grade). Data were collected for the kindergarten groups once during the school year, and twice for the first grade groups. Children were assessed via PA tasks at the level of syllables, rhymes, and phonemes; as well as via a single word reading task, and a letter knowledge task. Between group comparisons show bilingual children have significantly higher scores on most PA skills in Arabic. A cross-linguistic relationship was found for the bilingual children whereby PA abilities in Arabic were correlated with reading in English. Results also indicated a general improvement in PA skills for both monolinguals and bilinguals once literacy training had been introduced, as well as a clear bilingual advantage for reading post literacy training. It is argued that there is need for further research into this area, as well as a need for standardized tests in the Arabic language.
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Gilbert, Emma Louise. "Nuancing Northern Middle English : scribal language and variation in northern manuscripts of the Pricke of Conscience." Thesis, University of Leicester, 2014. http://hdl.handle.net/2381/28917.
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This thesis investigates the concept of the Northern Middle English dialect area as largely homogenous, taking its core data from four Northern manuscripts of the devotional poem, the Pricke of Conscience. Due largely to a lack of localised manuscripts from this region, the NME area has been little-studied. A Linguistic Atlas of Late Mediaeval English is an invaluable resource for the dialectologist, but where anchor texts are lacking, it cannot form a sole basis for study. This thesis approaches dialect study in the region from a different angle, compiling and comparing linguistic data from its core manuscripts to determine what variation can be observed. Each manuscript is also considered in its codicological and sociolinguistic context, using scribal behaviour as a means of illuminating the possible provenances of manusctipts and their language types. Finally, the data is considered alongside similar information from edited texts from this region, to place it in its proper context and examine what patterns of variation emerge. The findings of this thesis show a greater range of variation across the NME region than traditional descriptions would indicate. The variation attested demonatrates that some features previously held to be 'non-northern' or anomolous are, in fact, organically and consistently in use in this area. This study identifies and describes five language varieties observable within NME. The combination of textual and codicological evidence enables suggestions to be made about the identity of several of the scribes examined, connecting language varieties to occupation and possible provenance. This thesis presents a more nuanced, heterogeneous picture of the NME region, which may serve as a basis for further study in the area.
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Vinson, D. P. "Representing meaning : a feature-based model of object and action words." Thesis, University College London (University of London), 2009. http://discovery.ucl.ac.uk/14891/.
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The representation of word meaning has received substantial attention in the psycholinguistic literature over the past decades, yet the vast majority of studies have been limited to words referring to concrete objects. The aim of the present work is to provide a theoretically and neurally plausible model of lexical-semantic representations, not only for words referring to concrete objects but also for words referring to actions and events using a common set of assumptions across domains. In order to do so, features of meaning are generated by naïve speakers, and used as a window into important aspects of representation. A first series of analyses test how the meanings of words of different types are reflected in features associated with different modalities of sensory-motor experience, and how featural properties may be related to patterns of impairment in language-disordered populations. The features of meaning are then used to generate a model of lexical-semantic similarity, in which these different types of words are represented within a single system, under the assumption that lexical-semantic representations serve to provide an interface between conceptual knowledge derived in part from sensory-motor experience, and other linguistic information such as syntax, phonology and orthography. Predictions generated from this model are tested in a series of behavioural experiments designed to test two main questions: whether similarity measures based on speaker- generated features can predict fine-grained semantic similarity effects, and whether the predictive quality of the model is comparable for words referring to objects and words referring to actions. The results of five behavioural experiments consistently reveal graded semantic effects as predicted by the feature-based model, of similar magnitude for objects and actions. The model's fine-grained predictive performance is also found to be superior to other word-based models of representation (Latent Semantic Analysis, and similarity measures derived from Wordnet).
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Clements, Maria. "Exploring the role of previously acquired languages in third language (L3) acquisition : a feature-based approach." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/414200/.
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This thesis explores the role of previously acquired languages in third language (L3) acquisition, providing evidence that L3 transfer is determined by the underlying structural similarities and differences between previously acquired languages and the target L3. The analysis proposes a ‘feature-based’ approach to L3 transfer studies, highlighting the importance of linguistic features and the way in which they are assembled in different languages. I examine the acquisition of null and overt arguments by L1 English-L2 Spanish-L3 Chinese earners [+SP], conducting a comparative analysis with a group of L1 English-L2 non-null subject language-L3 Chinese learners [-SP]. The three languages of the [+SP] participants are not typologically related, but the L1 and L2 have similarities related to subject pronouns in the L3. Null subjects are allowed in Spanish and Chinese (although there are syntactic differences) and overt subjects behave in a similar way in English and Chinese. Therefore, transfer can occur from the L1 or L2. A Written Production Task (WPT) and a Pronoun Interpretation Task (PIT) test the use and interpretation of arguments, and a Language Relations Questionnaire (LRQ) explores the learners’ perceptions of the relatedness between languages. The results show transfer from L1 English (overt pronouns) and L2 Spanish (null subjects), indicating that L3 transfer can occur from either the L1/L2, depending on the property being acquired (i.e. it is selective). Furthermore, the data shows that the [+SP] group outperform the [-SP] group with null subjects, indicating that reassembling features associated with null subjects is straightforward despite syntactic differences between the languages. In addition, learners’ perceptions of language relatedness do not play an important role for typologically unrelated languages. Therefore, the study concludes that future L3 transfer studies can make more specific predictions regarding the source of transfer if linguistic features are taken into account.
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Iliadi, Konstantina. "Bio-inspired voice recognition for speaker identification." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/413949/.
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Speaker identification (SID) aims to identify the underlying speaker(s) given a speech utterance. In a speaker identification system, the first component is the front-end or feature extractor. Feature extraction transforms the raw speech signal into a compact but effective representation that is more stable and discriminative than the original signal. Since the front-end is the first component in the chain, the quality of the later components is strongly determined by its quality. Existing approaches have used several feature extraction methods that have been adopted directly from the speech recognition task. However, the nature of these two tasks is contradictory given that speaker variability is one of the major error sources in speech recognition whereas in speaker recognition, it is the information that we wish to extract. In this thesis, the possible benefits of adapting a biologically-inspired model of human auditory processing as part of the front-end of a SID system are examined. This auditory model named Auditory Image Model (AIM) generates the stabilized auditory image (SAI). Features are extracted by the SAI through breaking it into boxes of different scales. Vector quantization (VQ) is used to create the speaker database with the speakers’ reference templates that will be used for pattern matching with the features of the target speakers that need to be identified. Also, these features are compared to the Mel-frequency cepstral coefficients (MFCCs), which is the most evident example of a feature set that is extensively used in speaker recognition but originally developed for speech recognition purposes. Additionally, another important parameter in SID systems is the dimensionality of the features. This study addresses this issue by specifying the most speaker-specific features and trying to further improve the system configuration for obtaining a representation of the auditory features with lower dimensionality. Furthermore, after evaluating the system performance in quiet conditions, another primary topic of speaker recognition is investigated. SID systems can perform well under matched training and test conditions but their performance degrades significantly because of the mismatch caused by background noise in real-world environments. Achieving robustness to SID systems becomes an important research problem. In the second experimental part of this thesis, the developed version of the system is assessed for speaker data sets of different size. Clean speech is used for the training phase while speech in the presence of babble noise is used for speaker testing. The results suggest that the extracted auditory feature vectors lead to much better performance, i.e. higher SID accuracy, compared to the MFCC-based recognition system especially for low SNRs. Lastly, the system performance is inspected with regard to parameters related to the training and test speech data such as the duration of the spoken material. From these experiments, the system is found to produce satisfying identification scores for relatively short training and test speech segments.
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Bidgood, A. "The retreat from overgeneralisation errors : a multiple-paradigm approach." Thesis, University of Liverpool, 2016. http://livrepository.liverpool.ac.uk/3005561/.
Full textAbstract:
This thesis examines children’s argument structure overgeneralisation errors (e.g. *Don’t giggle me!). Errors of this kind arise from children observing that certain verbs can appear in more than one argument structure (e.g. The ball rolled/Homer rolled the ball). This pattern can be usefully generalised to allow children who have heard a verb produced in only one of these structures (e.g. The window opened) to produce it in the other (e.g. Marge opened the window). The ability to generalise patterns to new items is key to children becoming productive language users. However, if they overgeneralise this pattern, errors will result: Bart giggled is grammatical, but *Lisa giggled Bart (meaning Lisa made Bart giggle) is not. This thesis tested three hypotheses designed to explain how children retreat from such overgeneralisation errors, or, indeed, avoid making them altogether: the semantic verb class hypothesis (Pinker, 1989); the entrenchment hypothesis (Braine & Brooks, 1995); and the preemption hypothesis (Goldberg, 1995). Chapter 3 uses a novel-verb grammaticality judgment paradigm to investigate overgeneralisation errors in the locative construction (e.g. *Marge filled tea into the cup). Chapter 4 investigates overgeneralisation errors in the transitive and intransitive constructions, using a grammaticality judgment paradigm with known verbs, as well as a production priming paradigm designed to elicit errors from young children (e.g. *Homer swam the fish). Finally, in order to investigate the role of semantics in language development more generally, Chapter 5 moves beyond overgeneralisation errors to investigate children’s acquisition of the passive construction (e.g. Bart was helped by Lisa). This thesis adds to a growing body of work demonstrating that none of the individual theories (semantics, entrenchment, preemption) alone is able to explain children’s retreat from overgeneralisation, and that an integrated approach, such as that proposed by Ambridge and colleagues’ FIT account, is required to account for the data. The thesis moves our understanding forward by demonstrating both that this account can explain error patterns in production, and that the role of verb-in-construction semantic compatibility (a key aspect of the FIT account) can explain children’s acquisition of argument structure more widely.
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Kubisz, Anna. "Perception of social-indexical information in gender-ambiguous voices." Thesis, University of York, 2016. http://etheses.whiterose.ac.uk/17875/.
Full textAbstract:
This thesis presents innovative research which uses gender-ambiguous speech to investigate perceptions of speaker-indexical information. In a series of three perceptual experiments perceptions of speaker age, gender and social class are researched. In Experiment 1 listeners heard audio samples, on the basis of which they were asked to evaluate speaker age, gender and social class using a Visual Analogue Scale. Experiment 2 was performed in the interests of investigating how perceptions of the same speaker-indexical information as in Experiment 1 might be shifted when providing the listener with visual information about the supposed speaker. For example, upon seeing a young female face when hearing a phonetic variant, the listener might rate the variant differently from the answer s/he gave in response to the same stimulus in Experiment 1. In Experiment 3, a new social factor, ethnicity, was introduced. The aim of this experiment was to investigate perceptions of speaker-indexical information when listeners were exposed to visual cues to the ethnicity of the supposed speaker. As Experiment 2, Experiment 3 tested whether speaker-indexical information could be shifted as a result of the manipulation. Furthermore, this research offers a multivariate investigation of perception of speaker-indexical information based on Tyneside English. Perceptions of the variants of the FACE, GOAT and NURSE vowels, T-to-R and variants of /p t k/ are tested. Finally, the findings for groups of listeners with high and lower exposure to Tyneside English are compared and contrasted.