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Rôle différentiel des isoformes de PML en réponse au trioxyde d’arsenic et dans la défense antivirale / Differencial role of PML isoforms in arsenic trioxyde response and in antiviral defenseEl Asmi, Faten 13 December 2013 (has links)
Les interférons (IFN) constituent une famille de cytokines aux propriétés antiprolifératives et antivirales. Ils activent, via la voie Jak/STAT, des gènes spécifiques dont les produits sont les médiateurs des effets biologiques des IFN. C’est le cas de PML (Promyelocytic leukemia), appelée aussi TRIM19, qui joue un rôle central dans la défense antivirale. PML appartenant à la famille des protéines Tripartite Motif (TRIM), caractérisée par la présence en N-terminal d’un motif RBCC, constitué d’un domaine RING, d’une ou de deux boites B et d’un domaine coiled-coil. PML a été identifiée dans la leucémie aiguë promyélocytaire, une pathologie causée par la translocation chromosomique t(15 ;17) qui fusionne les gènes PML et RARA, aboutissant à la synthèse d'une protéine chimère PML-RARA. Le trioxyde d'arsenic (As2O3) cible la portion PML de la protéine oncogénique, entraînant sa dégradation et la rémission complète des patients. Dans les cellules saines, les transcrits PML issus d’un gène unique génèrent par épissage alternatif 7 isoformes principales de PML, dont six sont nucléaires (PMLI à PMLVI) et une cytoplasmique (PMLVIIb). Toutes possèdent la même extrémité N-terminale mais diffèrent au niveau de leur extrémité C-terminale, conférant à chaque isoforme des fonctions spécifiques.PML est l’organisatrice d’une structure multi-protéique appelée corps nucléaires (CN), impliquée dans divers processus cellulaires tels que l’apoptose, la dégradation des protéines ou encore la défense antivirale.PML est modifiée par SUMO de façon covalente au niveau de trois sites lysines (K65, K160, K490) et de façon non covalente, via son domaine SIM (pour « SUMO Interacting Motif »). Ces modifications sont requises pour la formation de CN fonctionnels et le recrutement de protéines partenaires au sein de ceux-ci. Le but de ma thèse a été d’étudier le rôle différentiel des différentes isoformes de PML en réponse à l’As2O3 et suite à l’infection virale. Nous avons montré que le SIM de PML est nécessaire à sa dégradation en réponse à l'As2O3. Ce motif est présent dans toutes les isoformes de PML, hormis l’isoforme nucléaire PMLVI et l’isoforme cytoplasmique PMLVIIb. Le SIM de PML n’est pas requis pour sa SUMOylation et son interaction avec RNF4 (une E3 ubiquitine ligase responsable de la dégradation de PML via le protéasome). En revanche, ce motif est requis pour l’ubiquitination de PML, le recrutement des composants du protéasome et sa dégradation en réponse à l’As2O3. Concernant les propriétés antivirales de PML, l’étude que nous avons menée avec toutes les isoformes de PML a permis de montrer que seules PMLIII et PMLIV confèrent une résistance au Virus de la Stomatite Vésiculaire (VSV). L’effet antiviral de PMLIII n'est observé qu'à faible multiplicité d’infection (MOI) et est indépendant de la production d’IFN. Par contre, PMLIV exerce une puissante activité anti-VSV, y compris à forte MOI et s'exerce selon deux mécanismes distincts : (i) PMLIV inhibe la réplication du VSV par un mécanisme précoce indépendant de l’IFN, (ii) PMLIV augmente tardivement la production d’IFN-β via une plus forte activation d’IRF3 qui est due à la séquestration spécifique de Pin1 au sein des CN par PMLIV. Ces deux processus nécessitent la SUMOylation de PMLIV. Ces résultats montrent que PMLIV exerce une activité antivirale intrinsèque et est impliquée dans l’immunité innée en régulant positivement la voie de transduction conduisant à la synthèse d’IFN-β. / Interferons (IFNs) are a family of cytokines with antiproliferative and antiviral properties.They activate, via the Jak/Stat pathway, specific genes whose products are the mediators of the biological effects of IFNs. This is the case of PML (Promyelocytic leukemia), also known as TRIM19, which plays a central role in antiviral defense.PML belongs to the Tripartite Motif (TRIM) protein family, characterized by the presence of an N- terminal RBCC pattern, consisting of a RING domain, one or two B-boxes and a coiled-coil domain. PML was identified in acute promyelocytic leukemia, a disease caused by the chromosomal translocation t(15 ;17), which fuses the PML and RARA genes, leading to the synthesis of a chimeric protein PML-RARA . Arsenic trioxide (As2O3) targets the PML moiety of the oncogenic protein, resulting in its degradation and in the complete remission of patients.In healthy cells, PML transcripts derived from a single gene generate seven major isoforms of PML by alternative splicing, including six nuclear (PMLI to PMLVI) and one cytoplasmic (PMLVIIb). All share the same N-terminus but differ at their C-terminus, giving each isoform specific functions.PML is the organizer of a multi-protein structure called nuclear bodies (NBs) that are involved in various cellular processes such as apoptosis, protein degradation or antiviral defense.PML is covalently modified by SUMO at three lysine residues (K65, K160, K490) but also non-covalently via its SIM domain (for « SUMO Interacting Motif »). These modifications are required for the formation of functional NBs and the recruitment of partner proteins within them.The aim of my thesis was to study the differential role of the different PML isoforms in response to As2O3 and during viral infection.We have shown that the SIM PML SIM is necessary for its degradation in response to As2O3. This motif is present in all PML isoforms, except the nuclear PMLVI and the cytoplasmic PMLVIIb isoforms. The SIM of PML is not required for its SUMOylation and its interaction with RNF4 (the E3 ubiquitin ligase responsible for PML proteasome-dependent degradation). However, this motif is required for the ubiquitination of PML, the recruitment of proteasome components and the degradation of PML in response to As2O3.Concerning the antiviral properties of PML, the study that we conducted with all PML isoforms allowed us to show that only PMLIII and PMLIV confer resistance to Vesicular Stomatitis Virus (VSV). Whereas the antiviral activity of PMLIII is only observed at low multiplicity of infection (MOI) and is independent of IFN production, PMLIV has a potent anti-VSV activity, including at high MOI, which is mediated through two distinct mechanisms: (i) PMLIV inhibits the replication of VSV by an early and IFN-independent mechanism, (ii) PMLIV later increases the production of IFN-β via a stronger activation of IRF3, which is due to the specific sequestration of Pin1 by PMLIV within NBs. Both processes require the PMLIV SUMOylation. These results show that PMLIV has an intrinsic antiviral activity and is also involved in innate immunity by positively regulating the transduction pathway leading to IFN-β synthesis.
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Zkvalitnění služby GSM Banking pro zákazníky T-Mobile. / Improving quality of GSM Banking services for T-Mobile customers.Bolehovská, Zuzana January 2007 (has links)
This diploma thesis on the theme Improving quality of GSM Banking services for T-Mobile customers deals with detailed analysis of the selected product, which the T-Mobile company has been mediating to all it´s customers for years. This analysis resides in comparing of GSM Banking services with other mobile operators operating on the contemporary Czech market. My thesis contains general theoretical and concrete practical resources, which offer possibilities of improving and innovation of the present situation.
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N-methyl 4-methyl amphetamine N-alkyl chain extension differentially affects ion flux at the human dopamine and norepinephrine transportersHarris, Alan C., Jr. 01 January 2016 (has links)
Amphetamine (AMPH) and its derivatives embody a remarkable breadth of pharmacology. These molecules exert their effects, both therapeutic and pathological, at the human monoamine transporters, which tune synaptic dynamics by evacuating monoamine neuromodulators from the synapse subsequent to neuronal impulses. These transporters are electrogenic, and the transporter-mediated current can be correlated to a surrogate measure of the change in membrane voltage: Ca++ currents from co-transfected L-type Ca++ channels. The present work makes use of this assay, with which it is possible to derive pharmacodynamic metrics from both substrates and inhibitors. This work presents data on a heretofore-unstudied class of amphetamine analogs: the enantiomers of N-Me 4-Me AMPH and N-Et 4-Me AMPH. Remarkably, while both enantiomers of the N-Me version of this compound function as substrates at hDAT, both enantiomers of the N-Et version are inhibitors. This switch does not occur at hNET, where all enantiomers of both N-Me and N-Et 4-Me AMPH function as substrates. Further, (S)-N-Et 4-Me AMPH is a substrate at dDAT. EC50 and IC50 values for all drugs at both transporters are presented. I present the results of super-resolution microscopic co-localization studies on the plasmalemmal spatial relation of the human dopamine transporter and voltage gated calcium channel, L-type 1.2 (CaV1.2). I discuss future aims toward a unified understanding of the mechanisms of monoamine transporter function, with an emphasis on what amphetamine can illuminate in this regard.
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Image analysis and computational modelling of Activity-Dependent Bulk Endocytosis in mammalian central nervous system neuronsStewart, Donal Patrick January 2017 (has links)
Synaptic vesicle recycling is the reuse of synaptic membrane material and proteins after vesicles have been exocytosed at the pre-synaptic terminal of a neuronal synapse. The discovery of the mechanisms by which recycling operates is a subject of active research. Within small mammalian central nervous system nerve terminals, two studied mechanisms of recovery are clathrin-mediated endocytosis and activity-dependent bulk endocytosis. Research into the comparative kinetics and mechanisms underlying these endocytosis mechanisms commonly involves time-series fluorescence microscopy of in vitro cultures. Synaptic proteins are tagged with fluorescent markers, or the synaptic vesicles are labelled with fluorescent dye. The change in fluorescence levels of individual synapses over time in response to stimuli is used to understand synaptic activity. The image analysis of these time-series images frequently requires substantial manual effort to extract the changing synaptic fluorescence intensity levels over time. This work focusses on two closely interlinked areas, the development of improved automated image analysis tools to facilitate the analysis of microscopy image data, and computational simulations to leverage the data obtained from these experiments to gain mechanistic insight into the underlying processes involved in synaptic vesicle recycling. The imaged properties of synapses within the time-series images are characterised, in terms of synapse movement during the course of an experiment. This characterisation highlights the properties which risk adding error to the extracted fluorescence intensity data, as analysis generally requires segmentation of regions of interest with fixed size and location. Where possible, protocols to optimise the manual selection of synapses in the image are suggested. The manual selection of synapses within time-series images is a common but time consuming and difficult task. It requires considerable skill on the part of the researcher to select synapses from noisy images without introducing error or bias. Automated tools for either general image segmentation or for segmentation of synapse-like puncta do exist, but have mixed results when applied to time-series experiments. This work introduces the use of knowledge of the experiment protocol into the segmentation process. The selection of synapses as they respond to known stimuli is compared against other current segmentation methods, and tools to perform this segmentation are provided. This use of synapse activity improves the quality of the segmented set of synapses over existing segmentation tools. Finally, this work builds a number of computational models, to allow published individual data points to be aggregated into a coherent view of overall synaptic vesicle recycling. The first is FM-Sim, a stochastic hybrid model of overall synapse recycling as is expected to occur during the course of an experiment. This closed system model handles the processes of exocytosis and endocytosis. It uses Bayesian inference to fit model parameters to experimental data. In particular, it uses the experimental protocol to separate the mechanisms and rates that may contribute to the observed experimental data. The second is a mathematical model of one aspect of synaptic vesicle recycling of particular interest - homoeostasis of plasma membrane integrity on the presynaptic terminal. This model provides bounds on efficiency of the studied endocytosis mechanisms at recovery of plasma membrane area during and after neuronal stimulus. Both the image analysis and the computational simulations demonstrated in this work provide useful tools and insights into current research of synaptic vesicle recycling and the role of activity-dependent bulk endocytosis. In particular, the utility of adding time-dependent experimental protocol knowledge to both the image analysis tools and the computational simulations is shown.
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Desenvolvimento de um método para determinação simultânea de compostos carbonílicos tóxicos durante a vinificação e avaliação do risco da exposição a estes compostosFerreira, Daiani Cecchin January 2017 (has links)
Propriedades benéficas são associadas ao consumo moderado de vinho devido à presença dos compostos fenólicos. Uma dose diária de vinho de até 200 ou 300 mL é sugerida para mulheres e homens, respectivamente. Entretanto, dentre os compostos presentes nos vinhos, podem ser encontrados compostos carbonílicos tóxicos, como o formaldeído, acroleína, acetaldeído, furfural e carbamato de etila, os quais tem sido associados a efeitos adversos à saúde humana, incluindo o câncer. O objetivo deste trabalho foi desenvolver e validar um método para a quantificação simultânea destes compostos tóxicos através da microextração em fase sólida no modo headspace associada à cromatografia gasosa acoplada à espectrometria de massas quadrupolar no modo de monitoramento de íons selecionados (HS-SPME- GC/qMS-SIM) e caracterizar o risco relacionado à exposição a estes compostos. Quatro etapas da vinificação (uva, mosto, após a fermentação alcoólica e vinho) e vinhos comercialmente disponíveis foram analisados com o uso da GC/qMS-SIM após verificar as coeluições através da cromatografia gasosa bidimensional abrangente acoplada ao detector de espectrometria de massas por tempo de voo (GC×GC- TOFMS). O acetaldeído e a acroleína derivatizados coeluíram na primeira dimensão cromatográfica com o limoneno e o hexanoato de metila, respectivamente. Em função disso, foram escolhidos como íons quantificadores na análise por GC/qMS, íons que não foram encontrados no espectro de massas dos compostos coeluídos. Os parâmetros de validação (LOD, LOQ, recuperação, repetibilidade e reprodutibilidade) mostraram que a HS-SPME-GC/qMS-SIM é adequada para quantificar simultaneamente os cinco compostos tóxicos. A acroleína foi encontrada em concentrações similares na uva e mosto, e não foi detectada após a fermentação alcoólica e no vinho. O acetaldeído foi detectado em menores concentrações no mosto e em maiores níveis após a fermentação alcoólica. A concentração de furfural foi maior nas uvas do que nas demais etapas. O carbamato de etila não foi detectado nas etapas da vinificação e nos vinhos comerciais. Os níveis de formaldeído ficaram entre os valores de LOD e LOQ em todas as etapas da vinificação e nos vinhos comerciais. Além disso, nos vinhos comercialmente disponíveis, a acroleína foi encontrada em 50% das amostras, o acetaldeído e o furfural estavam presentes em todas as amostras. O único composto cuja ingestão pode representar risco a saúde é a acroleína. Dessa forma, este estudo contribuiu para identificar os pontos críticos de controle relacionados à presença de compostos tóxicos durante a vinificação, incluindo a produção do acetaldeído durante a fermentação alcoólica e a contaminação das uvas com acroleína e furfural através do ar atmosférico. Além disso, os resultados da ocorrência destes compostos tóxicos em vinhos comercialmente disponíveis poderão contribuir para a criação de uma legislação nacional que estabeleça limites dos mesmos nesta bebida. / Beneficial properties are associated with moderate consumption of wine due to the presence of phenolic compounds. A daily intake of wine of up to 200 or 300 mL is suggested for women and men, respectively. However, toxic carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, furfural and ethyl carbamate can be found among the compounds present in wines, which have been associated with adverse effects on human health, including cancer. The objective of this work was to develop and validate a method for simultaneous quantification of these toxic compounds through headspace solid phase microextraction associated with gas chromatography with quadrupole mass spectrometric detection in selected-ion monitoring mode (HS-SPME-GC/qMS-SIM) and characterize the risk related to exposure to these compounds. Four vinification steps (grape, must, after alcoholic fermentation and wine) and commercially available wine were analyzed using GC/qMS-SIM after checking the coelutions by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS). The derivatized acetaldehyde and acrolein coeluted in the first chromatographic dimension with limonene and methyl hexanoate, respectively. Based on this, were chosen as quantifiers ions in GC/qMS analysis, ions that were not found in the mass spectra of the coeluted compounds. The validation parameters (LOD, LOQ, recovery, repeatability and reproducibility) showed that HS-SPME-GC/qMS-SIM is adequate to simultaneously quantify the five toxic compounds. Acrolein was found at similar concentrations in grape and must, and was not detected after alcoholic fermentation and in wine. Acetaldehyde was detected at lower concentrations in the must and at higher levels after alcoholic fermentation. The concentration of furfural was higher in the grapes than in the other stages. Ethyl carbamate was not detected in the vinification steps and in commercially wine. Formaldehyde levels were between the LOD and LOQ values at all stages of winemaking and commercial wines. In addition, in commercially available wines, acrolein was found in 50% of samples, acetaldehyde and furfural were present in all samples. The only compound whose intake may pose a health risk is acrolein. Thus, this study contributed to identify critical control point related to the presence of toxic compounds during winemaking, including the production of acetaldehyde during alcoholic fermentation and the contamination of grapes with acrolein and furfural through atmospheric air. In addition, the results of the occurrence of these toxic compounds in commercially available wines may contribute to the creation of national legislation that establishes limits of the same in this drink.
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Attribution and judgment : examining the relation between attributing capacities and moral judgments about killing animalsAndersson, Per January 2013 (has links)
A new operationalization was used to model a schema-based approach to moral judgment, as well as compare it to predictions based on the Social Intuitionist Model. Judgments were made about the moral wrongness of killing different animals. At Time 1, only moral judgments were made. At Time 2 judgments were made again, with questions and scales relating to attributing morally relevant cognitive capacities also included; further, two randomized conditions varied the presentation order of the scales. Differences between Time 1 and 2 indicated a reversed perspective-taking effect, with animals of lower capacities rated less empathically at Time 2. Affective ratings and attributed capacities were compared as different predictors, showing attributed capacities being more powerful. A group comparison was also made between active animal rights proponents and non-proponents, showing differences on several factors. These and other findings are discussed with relation to the Social Intuitionist Model and a schema-based account of morality.
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Desenvolvimento de um método para determinação simultânea de compostos carbonílicos tóxicos durante a vinificação e avaliação do risco da exposição a estes compostosFerreira, Daiani Cecchin January 2017 (has links)
Propriedades benéficas são associadas ao consumo moderado de vinho devido à presença dos compostos fenólicos. Uma dose diária de vinho de até 200 ou 300 mL é sugerida para mulheres e homens, respectivamente. Entretanto, dentre os compostos presentes nos vinhos, podem ser encontrados compostos carbonílicos tóxicos, como o formaldeído, acroleína, acetaldeído, furfural e carbamato de etila, os quais tem sido associados a efeitos adversos à saúde humana, incluindo o câncer. O objetivo deste trabalho foi desenvolver e validar um método para a quantificação simultânea destes compostos tóxicos através da microextração em fase sólida no modo headspace associada à cromatografia gasosa acoplada à espectrometria de massas quadrupolar no modo de monitoramento de íons selecionados (HS-SPME- GC/qMS-SIM) e caracterizar o risco relacionado à exposição a estes compostos. Quatro etapas da vinificação (uva, mosto, após a fermentação alcoólica e vinho) e vinhos comercialmente disponíveis foram analisados com o uso da GC/qMS-SIM após verificar as coeluições através da cromatografia gasosa bidimensional abrangente acoplada ao detector de espectrometria de massas por tempo de voo (GC×GC- TOFMS). O acetaldeído e a acroleína derivatizados coeluíram na primeira dimensão cromatográfica com o limoneno e o hexanoato de metila, respectivamente. Em função disso, foram escolhidos como íons quantificadores na análise por GC/qMS, íons que não foram encontrados no espectro de massas dos compostos coeluídos. Os parâmetros de validação (LOD, LOQ, recuperação, repetibilidade e reprodutibilidade) mostraram que a HS-SPME-GC/qMS-SIM é adequada para quantificar simultaneamente os cinco compostos tóxicos. A acroleína foi encontrada em concentrações similares na uva e mosto, e não foi detectada após a fermentação alcoólica e no vinho. O acetaldeído foi detectado em menores concentrações no mosto e em maiores níveis após a fermentação alcoólica. A concentração de furfural foi maior nas uvas do que nas demais etapas. O carbamato de etila não foi detectado nas etapas da vinificação e nos vinhos comerciais. Os níveis de formaldeído ficaram entre os valores de LOD e LOQ em todas as etapas da vinificação e nos vinhos comerciais. Além disso, nos vinhos comercialmente disponíveis, a acroleína foi encontrada em 50% das amostras, o acetaldeído e o furfural estavam presentes em todas as amostras. O único composto cuja ingestão pode representar risco a saúde é a acroleína. Dessa forma, este estudo contribuiu para identificar os pontos críticos de controle relacionados à presença de compostos tóxicos durante a vinificação, incluindo a produção do acetaldeído durante a fermentação alcoólica e a contaminação das uvas com acroleína e furfural através do ar atmosférico. Além disso, os resultados da ocorrência destes compostos tóxicos em vinhos comercialmente disponíveis poderão contribuir para a criação de uma legislação nacional que estabeleça limites dos mesmos nesta bebida. / Beneficial properties are associated with moderate consumption of wine due to the presence of phenolic compounds. A daily intake of wine of up to 200 or 300 mL is suggested for women and men, respectively. However, toxic carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, furfural and ethyl carbamate can be found among the compounds present in wines, which have been associated with adverse effects on human health, including cancer. The objective of this work was to develop and validate a method for simultaneous quantification of these toxic compounds through headspace solid phase microextraction associated with gas chromatography with quadrupole mass spectrometric detection in selected-ion monitoring mode (HS-SPME-GC/qMS-SIM) and characterize the risk related to exposure to these compounds. Four vinification steps (grape, must, after alcoholic fermentation and wine) and commercially available wine were analyzed using GC/qMS-SIM after checking the coelutions by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS). The derivatized acetaldehyde and acrolein coeluted in the first chromatographic dimension with limonene and methyl hexanoate, respectively. Based on this, were chosen as quantifiers ions in GC/qMS analysis, ions that were not found in the mass spectra of the coeluted compounds. The validation parameters (LOD, LOQ, recovery, repeatability and reproducibility) showed that HS-SPME-GC/qMS-SIM is adequate to simultaneously quantify the five toxic compounds. Acrolein was found at similar concentrations in grape and must, and was not detected after alcoholic fermentation and in wine. Acetaldehyde was detected at lower concentrations in the must and at higher levels after alcoholic fermentation. The concentration of furfural was higher in the grapes than in the other stages. Ethyl carbamate was not detected in the vinification steps and in commercially wine. Formaldehyde levels were between the LOD and LOQ values at all stages of winemaking and commercial wines. In addition, in commercially available wines, acrolein was found in 50% of samples, acetaldehyde and furfural were present in all samples. The only compound whose intake may pose a health risk is acrolein. Thus, this study contributed to identify critical control point related to the presence of toxic compounds during winemaking, including the production of acetaldehyde during alcoholic fermentation and the contamination of grapes with acrolein and furfural through atmospheric air. In addition, the results of the occurrence of these toxic compounds in commercially available wines may contribute to the creation of national legislation that establishes limits of the same in this drink.
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Arcabouço para reconhecimento de locutor baseado em aprendizado não supervisionado / Speaker recognition framework based on unsupervised learningCampos, Victor de Abreu [UNESP] 31 August 2017 (has links)
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Previous issue date: 2017-08-31 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A quantidade vertiginosa de conteúdo multimídia acumulada diariamente tem demandado o desenvolvimento de abordagens eficazes de recuperação. Nesse contexto, ferramentas de reconhecimento de locutor capazes de identificar automaticamente um indivíduo pela sua voz são de grande relevância. Este trabalho apresenta uma nova abordagem de reconhecimento de locutor modelado como um cenário de recuperação e usando algoritmos de aprendizado não supervisionado recentes. A abordagem proposta considera Coeficientes Cepstrais de Frequência Mel (MFCCs) e Coeficientes de Predição Linear Perceptual (PLPs) como características de locutor, em combinação com múltiplas abordagens de modelagem probabilística, especificamente Quantização Vetorial, Modelos por Mistura de Gaussianas e i-vectors, para calcular distâncias entre gravações de áudio. Em seguida, métodos de aprendizado não supervisionado baseados em ranqueamento são utilizados para aperfeiçoar a eficácia dos resultados de recuperação e, com a aplicação de um classificador de K-Vizinhos Mais Próximos, toma-se uma decisão quanto a identidade do locutor. Experimentos foram conduzidos considerando três conjuntos de dados públicos de diferentes cenários e carregando ruídos de diversas origens. Resultados da avaliação experimental demonstram que a abordagem proposta pode atingir resultados de eficácia altos. Adicionalmente, ganhos de eficácia relativos de até +318% foram obtidos pelo procedimento de aprendizado não supervisionado na tarefa de recuperação de locutor e ganhos de acurácia relativos de até +7,05% na tarefa de identificação entre gravações de domínios diferentes. / The huge amount of multimedia content accumulated daily has demanded the development of effective retrieval approaches. In this context, speaker recognition tools capable of automatically identifying a person through their voice are of great relevance. This work presents a novel speaker recognition approach modelled as a retrieval scenario and using recent unsupervised learning methods. The proposed approach considers Mel-Frequency Cepstral Coefficients (MFCCs) and Perceptual Linear Prediction Coefficients (PLPs) as features along with multiple modelling approaches, namely Vector Quantization, Gaussian Mixture Models and i-vector to compute distances among audio objects. Next, rank-based unsupervised learning methods are used for improving the effectiveness of retrieval results and, based on a K-Nearest Neighbors classifier, an identity decision is taken. Several experiments were conducted considering three public datasets from different scenarios, carrying noise from various sources. Experimental results demonstrate that the proposed approach can achieve very high effectiveness results. In addition, effectiveness gains up to +318% were obtained by the unsupervised learning procedure in a speaker retrieval task. Also, accuracy gains up to +7,05% were obtained by the unsupervised learning procedure in a speaker identification task considering recordings from different domains. / FAPESP: 2015/07934-4
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Desenvolvimento de um método para determinação simultânea de compostos carbonílicos tóxicos durante a vinificação e avaliação do risco da exposição a estes compostosFerreira, Daiani Cecchin January 2017 (has links)
Propriedades benéficas são associadas ao consumo moderado de vinho devido à presença dos compostos fenólicos. Uma dose diária de vinho de até 200 ou 300 mL é sugerida para mulheres e homens, respectivamente. Entretanto, dentre os compostos presentes nos vinhos, podem ser encontrados compostos carbonílicos tóxicos, como o formaldeído, acroleína, acetaldeído, furfural e carbamato de etila, os quais tem sido associados a efeitos adversos à saúde humana, incluindo o câncer. O objetivo deste trabalho foi desenvolver e validar um método para a quantificação simultânea destes compostos tóxicos através da microextração em fase sólida no modo headspace associada à cromatografia gasosa acoplada à espectrometria de massas quadrupolar no modo de monitoramento de íons selecionados (HS-SPME- GC/qMS-SIM) e caracterizar o risco relacionado à exposição a estes compostos. Quatro etapas da vinificação (uva, mosto, após a fermentação alcoólica e vinho) e vinhos comercialmente disponíveis foram analisados com o uso da GC/qMS-SIM após verificar as coeluições através da cromatografia gasosa bidimensional abrangente acoplada ao detector de espectrometria de massas por tempo de voo (GC×GC- TOFMS). O acetaldeído e a acroleína derivatizados coeluíram na primeira dimensão cromatográfica com o limoneno e o hexanoato de metila, respectivamente. Em função disso, foram escolhidos como íons quantificadores na análise por GC/qMS, íons que não foram encontrados no espectro de massas dos compostos coeluídos. Os parâmetros de validação (LOD, LOQ, recuperação, repetibilidade e reprodutibilidade) mostraram que a HS-SPME-GC/qMS-SIM é adequada para quantificar simultaneamente os cinco compostos tóxicos. A acroleína foi encontrada em concentrações similares na uva e mosto, e não foi detectada após a fermentação alcoólica e no vinho. O acetaldeído foi detectado em menores concentrações no mosto e em maiores níveis após a fermentação alcoólica. A concentração de furfural foi maior nas uvas do que nas demais etapas. O carbamato de etila não foi detectado nas etapas da vinificação e nos vinhos comerciais. Os níveis de formaldeído ficaram entre os valores de LOD e LOQ em todas as etapas da vinificação e nos vinhos comerciais. Além disso, nos vinhos comercialmente disponíveis, a acroleína foi encontrada em 50% das amostras, o acetaldeído e o furfural estavam presentes em todas as amostras. O único composto cuja ingestão pode representar risco a saúde é a acroleína. Dessa forma, este estudo contribuiu para identificar os pontos críticos de controle relacionados à presença de compostos tóxicos durante a vinificação, incluindo a produção do acetaldeído durante a fermentação alcoólica e a contaminação das uvas com acroleína e furfural através do ar atmosférico. Além disso, os resultados da ocorrência destes compostos tóxicos em vinhos comercialmente disponíveis poderão contribuir para a criação de uma legislação nacional que estabeleça limites dos mesmos nesta bebida. / Beneficial properties are associated with moderate consumption of wine due to the presence of phenolic compounds. A daily intake of wine of up to 200 or 300 mL is suggested for women and men, respectively. However, toxic carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, furfural and ethyl carbamate can be found among the compounds present in wines, which have been associated with adverse effects on human health, including cancer. The objective of this work was to develop and validate a method for simultaneous quantification of these toxic compounds through headspace solid phase microextraction associated with gas chromatography with quadrupole mass spectrometric detection in selected-ion monitoring mode (HS-SPME-GC/qMS-SIM) and characterize the risk related to exposure to these compounds. Four vinification steps (grape, must, after alcoholic fermentation and wine) and commercially available wine were analyzed using GC/qMS-SIM after checking the coelutions by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS). The derivatized acetaldehyde and acrolein coeluted in the first chromatographic dimension with limonene and methyl hexanoate, respectively. Based on this, were chosen as quantifiers ions in GC/qMS analysis, ions that were not found in the mass spectra of the coeluted compounds. The validation parameters (LOD, LOQ, recovery, repeatability and reproducibility) showed that HS-SPME-GC/qMS-SIM is adequate to simultaneously quantify the five toxic compounds. Acrolein was found at similar concentrations in grape and must, and was not detected after alcoholic fermentation and in wine. Acetaldehyde was detected at lower concentrations in the must and at higher levels after alcoholic fermentation. The concentration of furfural was higher in the grapes than in the other stages. Ethyl carbamate was not detected in the vinification steps and in commercially wine. Formaldehyde levels were between the LOD and LOQ values at all stages of winemaking and commercial wines. In addition, in commercially available wines, acrolein was found in 50% of samples, acetaldehyde and furfural were present in all samples. The only compound whose intake may pose a health risk is acrolein. Thus, this study contributed to identify critical control point related to the presence of toxic compounds during winemaking, including the production of acetaldehyde during alcoholic fermentation and the contamination of grapes with acrolein and furfural through atmospheric air. In addition, the results of the occurrence of these toxic compounds in commercially available wines may contribute to the creation of national legislation that establishes limits of the same in this drink.
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Snabb och säker roaming i WLAN / Fast and Secure Roaming in WLANFalk, Magnus January 2004 (has links)
This thesis investigates how Ericsson AB should do to achieve fast and secure handover when roaming in a WLAN. It also provides a security analysis of the system that the wireless access point is part of. The reason for this is that Ericsson is selling an access point called the ABS 2200 aimed at the public hotspot market. The premise was that they wanted a standardized way of handling the roaming issue. At the outset the 802.11F standard looked like a good alternative (in fact the only standardized alternative). Towards last stages of the work though, it was discovered that the 802.11F standard is no longer supported by IEEE. Despite this fact, the conclusion is that secure and fast roaming can be attained if 802.11F is combined with the security standard 802.11i. The security analysis concludes that Denial Of Service is a major threat to WLAN hotspots. It also points out the link between the access point and authentication server is the weakest link in the system. The recommendation is that this link receives an additional layer of protection through IPsec withESP. The algorithm recommendations for ESP are AES for confidentiality and SHA-1 for integrity. This thesis can also be used as a primer on security in WLAN and contains an extensive glossary making it useful as a reference when reading 802.11 standards.
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