587 resultados para Audiometria tonal limiar
Resumo:
More information is now readily available to computer users than at any time in human history; however, much of this information is often inaccessible to people with blindness or low-vision, for whom information must be presented non-visually. Currently, screen readers are able to verbalize on-screen text using text-to-speech (TTS) synthesis; however, much of this vocalization is inadequate for browsing the Internet. An auditory interface that incorporates auditory-spatial orientation was created and tested. For information that can be structured as a two-dimensional table, links can be semantically grouped as cells in a row within an auditory table, which provides a consistent structure for auditory navigation. An auditory display prototype was tested.^ Sixteen legally blind subjects participated in this research study. Results demonstrated that stereo panning was an effective technique for audio-spatially orienting non-visual navigation in a five-row, six-column HTML table as compared to a centered, stationary synthesized voice. These results were based on measuring the time- to-target (TTT), or the amount of time elapsed from the first prompting to the selection of each tabular link. Preliminary analysis of the TTT values recorded during the experiment showed that the populations did not conform to the ANOVA requirements of normality and equality of variances. Therefore, the data were transformed using the natural logarithm. The repeated-measures two-factor ANOVA results show that the logarithmically-transformed TTTs were significantly affected by the tonal variation method, F(1,15) = 6.194, p= 0.025. Similarly, the results show that the logarithmically transformed TTTs were marginally affected by the stereo spatialization method, F(1,15) = 4.240, p=0.057. The results show that the logarithmically transformed TTTs were not significantly affected by the interaction of both methods, F(1,15) = 1.381, p=0.258. These results suggest that some confusion may be caused in the subject when employing both of these methods simultaneously. The significant effect of tonal variation indicates that the effect is actually increasing the average TTT. In other words, the presence of preceding tones increases task completion time on average. The marginally-significant effect of stereo spatialization decreases the average log(TTT) from 2.405 to 2.264.^
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Nicotine administration in humans and rodents enhances memory and attention, and also has a positive effect in Alzheimer's Disease. The Medial Septum / Diagonal Band of Broca complex (MS/DBB) – a main cholinergic system – massively projects to the hippocampus through the fimbria-fornix, and this pathway is called the septohippocampal pathway. It has been demonstrated that the MS/DBB acts directly on the local field potential (LFP) rhythmic organization of the hippocampus, especially in the rhythmogenesis of Theta (4-8Hz) – an oscillation intrinsically linked to hippocampus mnemonic function. In vitro experiments gave evidence that nicotine applied to the MS/DBB generates a local network Theta rhythm within the MS/DBB. Thus, the present study proposes to elucidate the function of nicotine in the MS/DBB on the septo-hippocampal pathway. In vivo experiments compared the effect of MS/DBB microinfusion of saline (n=5) and nicotine (n=8) on Ketamine/Xylazine anaesthetized mice. We observed power spectrum density in the Gamma range (35 to 55 Hz) increasing in both structures (Wilcoxon Rank-Sum test, p=0.038) but with no change in coherence between these structures in the same range (Wilcoxon Rank-Sum test, p=0.60). There was also a decrease in power of the ketamineinduced Delta oscillation (1 to 3 Hz). We also performed in vitro experiments on the effect of nicotine on membrane voltage and action potential. We patch-clamped 22 neurons in current-clamp mode; 12 neurons were responsive to nicotine, half of them increased firing rate and other 6 decreased, and they significantly differed in action potential threshold (-47.3±0.9 mV vs. -41±1.9 mV, respectively, p=0.007) and halfwidth time (1.6±0.08 ms vs. 2±0.12 ms, respectively, p=0.01). Furthermore, we performed another set of in vitro experiments concerning the connectivity of the three major neuronal populations of MS/DBB that use acetylcholine, GABA or glutamate as neurotransmitter. Paired patch-clamp recordings found that glutamatergic and GABAergic neurons realize intra-septal connections that produce sizable currents in MS/DBB postsynaptic neurons. The probability of connectivity between different neuronal populations gave rise to a MS/DBB topology that was implemented in a realistic model, which corroborates that the network is highly sensitive to the generation of Gamma rhythm. Together, the data available in the full set of experiments suggests that nicotine may act as a cognitive enhancer, by inducing gamma oscillation in the local circuitry of the MS/DBB.
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O NAVSTAR/GPS (NAVigation System with Timing And Ranging/Global Po- sitioning System), mais conhecido por GPS, _e um sistema de navegacão baseado em sat_elites desenvolvido pelo departamento de defesa norte-americano em meados de 1970. Criado inicialmente para fins militares, o GPS foi adaptado para o uso civil. Para fazer a localização, o receptor precisa fazer a aquisição de sinais dos satélites visíveis. Essa etapa é de extrema importância, pois é responsável pela detecção dos satélites visíveis, calculando suas respectivas frequências e fases iniciais. Esse processo pode demandar bastante tempo de processamento e precisa ser implementado de forma eficiente. Várias técnicas são utilizadas atualmente, mas a maioria delas colocam em conflito questões de projeto tais como, complexidade computacional, tempo de aquisição e recursos computacionais. Objetivando equilibrar essas questões, foi desenvolvido um método que reduz a complexidade do processo de aquisição utilizando algumas estratégias, a saber, redução do efeito doppler, amostras e tamanho do sinal utilizados, além do paralelismo. Essa estratégia é dividida em dois passos, um grosseiro em todo o espaço de busca e um fino apenas na região identificada previamente pela primeira etapa. Devido a busca grosseira, o limiar do algoritmo convencional não era mais aceitável. Nesse sentido, um novo limiar foi estabelecido baseado na variância dos picos de correlação. Inicialmente, é feita uma busca com pouca precisão comparando a variância dos cinco maiores picos de correlação encontrados. Caso a variância ultrapasse um certo limiar, a região de maior pico torna-se candidata à detecção. Por fim, essa região passa por um refinamento para se ter a certeza de detecção. Os resultados mostram que houve uma redução significativa na complexidade e no tempo de execução, sem que tenha sido necessário utilizar algoritmos muito complexos.
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Trace gases are important to our environment even though their presence comes only by ‘traces’, but their concentrations must be monitored, so any necessary interventions can be done at the right time. There are some lower and upper boundaries which produce nice conditions for our lives and then monitoring trace gases comes as an essential task nowadays to be accomplished by many techniques. One of them is the differential optical absorption spectroscopy (DOAS), which consists mathematically on a regression - the classical method uses least-squares - to retrieve the trace gases concentrations. In order to achieve better results, many works have tried out different techniques instead of the classical approach. Some have tried to preprocess the signals to be analyzed by a denoising procedure - e.g. discrete wavelet transform (DWT). This work presents a semi-empirical study to find out the most suitable DWT family to be used in this denoising. The search seeks among many well-known families the one to better remove the noise, keeping the original signal’s main features, then by decreasing the noise, the residual left after the regression is done decreases too. The analysis take account the wavelet decomposition level, the threshold to be applied on the detail coefficients and how to apply them - hard or soft thresholding. The signals used come from an open and online data base which contains characteristic signals from some trace gases usually studied.
Resumo:
Trace gases are important to our environment even though their presence comes only by ‘traces’, but their concentrations must be monitored, so any necessary interventions can be done at the right time. There are some lower and upper boundaries which produce nice conditions for our lives and then monitoring trace gases comes as an essential task nowadays to be accomplished by many techniques. One of them is the differential optical absorption spectroscopy (DOAS), which consists mathematically on a regression - the classical method uses least-squares - to retrieve the trace gases concentrations. In order to achieve better results, many works have tried out different techniques instead of the classical approach. Some have tried to preprocess the signals to be analyzed by a denoising procedure - e.g. discrete wavelet transform (DWT). This work presents a semi-empirical study to find out the most suitable DWT family to be used in this denoising. The search seeks among many well-known families the one to better remove the noise, keeping the original signal’s main features, then by decreasing the noise, the residual left after the regression is done decreases too. The analysis take account the wavelet decomposition level, the threshold to be applied on the detail coefficients and how to apply them - hard or soft thresholding. The signals used come from an open and online data base which contains characteristic signals from some trace gases usually studied.
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Les fichiers qui accompagnent mon document on été réalisés avec les logiciels Microsoft Word et Finale.
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A poluição marinha é um problema ambiental Mundial que afeta as constituintes bióticas e abióticas do Ecossistema. Os resultados de diversas atividades antropogénicas chegam ao meio marinho através de escorrências terrestres, industriais e agrícolas assim como através de descargas domésticas, causando distúrbios neste Ecossistema. Sendo assim, a avaliação da contaminação por metais é uma das prioridades tendo em conta que estes químicos têm comportamentos acumulativos e podem ser transportados ao longo de grandes distâncias. Nos estuários, os bivalves são componentes chaves das comunidades macrobentónicas devido o seu papel vital na comunidade e também por serem uma ótima fonte de alimentação para os seres Humanos. Na Lagoa de Óbidos, uma das espécies com estas características e intensamente apanhada é o berbigão Cerastoderma edule. Este berbigão foi descrito por vários autores como sendo tolerante a diversos poluentes. Sendo assim, no presente estudo, o principal objetivo foi utilizar C. edule como ferramenta de biomonitorização de contaminações por metais na Lagoa de Óbidos, avaliando a contaminação por Cádmio, Chumbo e Níquel durante as estações do ano de 2009 e 2010 em duas estações de amostragens (estação ML e BSB). Os resultados foram complementados com a análise de contaminações por metais em amostras de águas e sedimentos. Diversas respostas fisiológicas do berbigão foram também averiguadas de modo a perceber os efeitos da presença de metais e sua acumulação. Finalmente, avaliou-se a Dose Semanal Admissível Provisória (DSAP) para o consumo de berbigão para os mínimos e máximos de concentrações de metais detetados em cada estação de amostragem. Todos os metais foram detetados em amostras de água enquanto apenas o Pb foi detetado no sedimento. O Pb e o Ni foram detetados mais vezes na amostras biológicas do que o Cd. No entanto, as contaminações por metais Pb e Cd no berbigão foram frequentemente acima do limiar fixado pelas autoridades responsáveis enquanto o Ni se encontrou perto dos valores legislados. A avaliação da DSAP revelou a necessidade de aumentar a monitorização biológica neste berbigão visto que a dose semanal admissível foi muito baixa para os três metais. De um modo geral, C. edule refletiu as modificações ambientais, respondendo a modificações físico-químicas e contaminações por metais durante o período de estudo em ambas as estações de amostragem. Assim, este estudo permitiu concluir que Cerastoderma edule foi um bom e sensível indicador de contaminações por metais, especialmente para o Pb e preferencialmente para o Ni.
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The role of source properties in across-formant integration was explored using three-formant (F1+F2+F3) analogues of natural sentences (targets). In experiment 1, F1+F3 were harmonic analogues (H1+H3) generated using a monotonous buzz source and second-order resonators; in experiment 2, F1+F3 were tonal analogues (T1+T3). F2 could take either form (H2 or T2). Target formants were always presented monaurally; the receiving ear was assigned randomly on each trial. In some conditions, only the target was present; in others, a competitor for F2 (F2C) was presented contralaterally. Buzz-excited or tonal competitors were created using the time-reversed frequency and amplitude contours of F2. Listeners must reject F2C to optimize keyword recognition. Whether or not a competitor was present, there was no effect of source mismatch between F1+F3 and F2. The impact of adding F2C was modest when it was tonal but large when it was harmonic, irrespective of whether F2C matched F1+F3. This pattern was maintained when harmonic and tonal counterparts were loudness-matched (experiment 3). Source type and competition, rather than acoustic similarity, governed the phonetic contribution of a formant. Contrary to earlier research using dichotic targets, requiring across-ear integration to optimize intelligibility, H2C was an equally effective informational masker for H2 as for T2.
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In this article music therapy is presented as a helpful tool to support the persons (and their relatives) living at the end of their life and, also, as a non pharmacological and complementary therapy in an integral and holistic medicine. What we report here comes from the direct experience, nourished after many years of interventions and reflections in oncology and palliative care units. We’re talking about silence, music, therapy, models and techniques. We will read and feel therapeutic sessions… but above all, we’re talking about life, conscience and love.
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Franz Liszt has all too often been discarded as the virtuosic showman, despite the fact that his several of works have often gained great praise and attracted scholarly engagement. However, one also finds striking development of formal design and tonal harmony in many of the works for his principal composition medium, the piano. This paper seeks to explore the practical application of James A. Hepokoski and Warren Darcy’s 'Sonata Theory' upon Liszt’s magnum opus for the instrument, the Sonata in B Minor.
I shall first consider the historical analyses placed upon the work that deal with structural design, as it pertains to the paradigm of Classical sonata-form. Previous research reveals two main theoretical camps; those in favour of a multi-movement analysis (with conflicting hypotheses therein) and those in favour of a single movement sonata-form. An understanding of these historical conceptions of the piece allows one to then highlight areas of conflict and offer a new solution.
Finally, I shall use Sonata Theory to survey the Sonata in B Minor’s landscape in a new light. The title ‘Sonata’ has clear generic implications, many of which are met by Liszt; 'Sonata Theory' provides a model with which to outline the compositional deformations employed by the composer and the implications of this practice. In particular, I offer new perspectives on the validity of the double-function form, insight into the rhetorical layout of a rotational discourse, and propose a nuanced analysis befitting of this striking work.
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BRUNO, S. S. ; SOUSA, M. B. C. . Modulação pela progesterona da sensibilidade dolorosa a estímulos mecânicos e isquêmicos em mulheres saudáveis e jovens. RBGO. Revista Brasileira de Ginecologia e Obstetrícia , v. 30, p. 306-311, 2008
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This PhD thesis examines a phenomenon known as Monosyllabic Circumflexion (MC, hereafter) from a historical linguistics / phonological point of view. MC denotes a Lithuanian or Balto-Slavic phenomenon according to which long vowels and diphthongs in monosyllabic words exhibit a circumflex tone instead of the expected acute tone. It is observed in the following four categories: I. 3rd person future forms of monosyllabic stems (e.g., šõks ― šókti `to jump;' vy͂s ― výti `to drive') II. reflexes of PIE root nouns (e.g., Latv. gùovs `cow;' Lith. šuõ `dog') III. prepositions/adverbs (e.g., nuõ `from' ~ nùotaka `bride;' vė͂l `again' ~ Latv. vêl `still, yet,' tė͂ (permissive particle) < *teh1) IV. pronominal forms (e.g., tuõ ~ gerúoju `the good (m.~sg.~instr.),' tie͂ ~ tíeji `id. (pl.nom)'). The unexpected circumflex tone in these categories is problematic and important for the solution of a Balto-Slavic accentological question on the etymological background of acute and non-acute tones. The aim of this thesis is to partially contribute to the solution of this problem by establishing the existence of MC and its relative chronology. The first category, the 3rd person future forms, provides a substantial number of examples and counterexamples. The examination of them has revealed the fact that the counterexamples constitute a morpho-semantic group of verbs whose future stems underwent considerable morphological changes in the prehistory, hence not exhibiting MC. This shows that the regular tonal reflex of the 3rd person future forms of monosyllabic acute stem must be circumflex, allowing for the establishment of MC as a regular phonological process, although this category does not provide much information on the relative chronology of MC. The second category, the reflexes of Proto-Indo-European root nouns, gives an important clue as to where MC is located in the relative chronology of Balto-Slavic sound changes. Next, there is a discussion of whether the results of the examinations of the first two categories can be maintained for the data of the third and fourth categories, which show an irregular distribution of the acute and circumflex tones in monosyllabic forms. It is shown that various morphological factors, such as homonymic clashes within the paradigms for pronouns, can explain why some monosyllabic forms have acute tone. Also, the linguistic feature of West Aukštaitian dialects of Lithuanian that tend to preserve the results of MC is revealed. These dialects are known to have played an important role in the formation of standard Lithuanian. In this way, the monosyllabic forms with unexpected circumflex tone in Lithuanian are explained as a combination of MC in the Proto-Balto-Slavic time and the dialectal tendency of West Aukštaitian dialects of Lithuanian.
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Hierarchical structure with nested nonlocal dependencies is a key feature of human language and can be identified theoretically in most pieces of tonal music. However, previous studies have argued against the perception of such structures in music. Here, we show processing of nonlocal dependencies in music. We presented chorales by J. S. Bach and modified versions inwhich the hierarchical structure was rendered irregular whereas the local structure was kept intact. Brain electric responses differed between regular and irregular hierarchical structures, in both musicians and nonmusicians. This finding indicates that, when listening to music, humans apply cognitive processes that are capable of dealing with longdistance dependencies resulting from hierarchically organized syntactic structures. Our results reveal that a brain mechanism fundamental for syntactic processing is engaged during the perception of music, indicating that processing of hierarchical structure with nested nonlocal dependencies is not just a key component of human language, but a multidomain capacity of human cognition.
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Introdução: A oclusão da artéria hipogástrica pode ser necessária na reparação endovascular de aneurismas da aorta abdominal (EVAR). A oclusão intencional da hipogástrica pode ter complicações isquémicas. As endopróteses de bifurcação ilíaca (IBD) surgiram como alternativa endovascular à oclusão da hipogástrica em doentes com elevado risco para isquemia pélvica. Os autores descrevem um caso de oclusão precoce do ramo hipogástrico de IBD com graves consequências clínicas. Caso clínico: Sexo masculino, de 74 anos, com aneurisma da aorta abdominal (diâmetro máximo de 55 mm) com envolvimento de ambas as bifurcações ilíacas e segmentos proximais das hipogástricas (diâmetro máximo de 31 e 32 mm), submetido a EVAR com revascularização hipogástrica esquerda via IBD (Cook Zenith®) e coiling+overstenting da artéria hipogástrica contralateral. O procedimento decorreu sem complicações e a angiografia final mostrava permeabilidade da hipogástrica revascularizada e escassa colateralidade pélvica. O pós-operatório imediato complicou-se de dor lombar e glútea bilateral associada a manifestações cutâneas isquémicas e monoparesia do membro inferior esquerdo. Por agravamento progressivo nas primeiras 24h e angioTC com oclusão do stent da hipogástrica esquerda, procedeu-se novamente a revascularização da hipogástrica, com bom resultado na angiografia final. Apesar da revascularização bem-sucedida, houve agravamento progressivo do estado geral, com isquemia pélvica irreversível e rabdomiólise. Óbito ao 5.◦dia pós-operatório. Conclusão: A isquemia pélvica aguda é uma complicação grave e frequentemente fatal que pode advir da oclusão bilateral das artérias hipogástricas. A falência da revascularização por IBD pode ser fatal, pelo que os autores aconselham um cuidado redobrado no controlo angiográfico final e um baixo limiar para investigação na suspeita de complicações pós-operatórias. Se maior risco de falência técnica, embolização ou escassa colateralidade pélvica, a preservação bilateral de fluxo nas artérias hipogástricas pode estar recomendada.
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Le contrôle de bruit est un domaine de recherche très fertile. Que ce soit pour du contrôle actif ou passif, de nombreuses recherches sont menées pour améliorer les méthodes existantes ou pour trouver de nouveaux procédés. Ainsi, dans le domaine du contrôle actif, de nouveaux moyens de production d’anti-bruit sont développés en vue de les substituer aux duos amplificateur/haut-parleur fragiles, gourmands en énergie et encombrants. Le sujet abordé ici est la conception et la réalisation d’un prototype capable de générer de forts niveaux de bruit à partir d’une source d’écoulement d’air à fort débit. Le prototype servira ensuite de source pour le contrôle actif du bruit d’un ventilateur. Pour atteindre ces performances, un design simple a été développé : l’obstruction périodique de l’écoulement d’air comprimé génère une source acoustique harmonique à la fréquence d’obstruction de l’écoulement. Le contrôle de la vitesse de l’obstruction gère la fréquence et la phase de l’anti-bruit émis. Le dispositif conçu dans ce projet permet de générer un bruit tonal réglé en phase et en fréquence sur une référence, pour une pression acoustique de 110 dB à 1 m.