• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 380
  • 218
  • 96
  • 55
  • 45
  • 40
  • 16
  • 12
  • 12
  • 12
  • 12
  • 12
  • 12
  • 10
  • 10
  • Tagged with
  • 1051
  • 276
  • 213
  • 206
  • 140
  • 114
  • 108
  • 76
  • 61
  • 53
  • 51
  • 50
  • 49
  • 48
  • 47
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

Balada, canção e outros sons: um estudo fonoestilístico em Língua Portuguesa / Ballade, songs and others sounds: a phonostylistical study in Portuguese language

Magalí Elisabete Sparano 24 March 2006 (has links)
Esta tese de doutorado apresenta como objetivo analisar a transformação que ocorre, no período clássico e no moderno, das formas: balada, canção, ode e soneto, da poesia em Língua Portuguesa, considerando os conceitos estabelecidos pela tradição poética. Essa transformação é observada sob o aspecto fonoestilístico, com ênfase na sonoridade que compõe os poemas: traços fonológicos, rimas, ritmo e metro. Destaque-se ainda que o foco será o estudo dessas características sonoras, a sua expressividade e como se desenvolve a combinação desses elementos, na constituição do(s) sentido(s), no interior dos poemas. / The present PhD thesis aims at analyzing the changes that occur in the classical and modern periods on some forms such as: ballade, song, ode and sonnet of the poetry in Portuguese. For this it was taken into consideration the established concepts which guide the poetry tradition. The transformation mentioned above is seen from the phonostylistics point of view with emphasis in the following sonority features, which constitute the poems: phonological traces, rhymes, rhythm and meter. It is relevant to mention that the focus given will be the study of such sonority features, the expressiveness presented by them and how the combinations of these elements are developed so as to achieve the constitution of the meaning(s) within the poems.
222

Avaliação do efeito da dessincronização circadiana sobre o câncer de mama e utilização terapêutica de melatonina em ratas sprague-dawley

Sasso, Etianne Martini January 2013 (has links)
O câncer de mama é o tipo de câncer que mais acomete as mulheres e a principal causa de morte na faixa entre 40 e 55 anos. Apesar de apresentar variação internacional, suas taxas seguem aumentando mundialmente, sendo até cinco vezes mais frequente em países desenvolvidos. A industrialização gera aumento da exposição à luz durante a noite, o que causa supressão de melatonina. A melatonina é o principal hormônio secretado pela glândula pineal e possui atividade oncostática e antioxidante, interfere no controle do ciclo celular, função imunológica e nos hormônios esteróides. O objetivo desta dissertação e apresentar o racional e o desenvolvimento do estudo cujo objetivo foi avaliar o efeito da terapia com melatonina sobre o desenvolvimento de tumores mamários em ratas expostas ou não a dessincronização circadiana. A indução da carcinogênese mamária foi através de administração intragástrica de DMBA em 39 ratas Sprague-dawley entre 41 e 46 dias. Os animais foram randomizados em 04 grupos, Sincronizados sem tratamento, Dessincronizados sem tratamento, Sincronizados com melatonina e Dessincronizados com melatonina. Os grupos Sincronizados foram mantidos em ciclo claro/escuro de 12/12 horas e os dessincronizados a ciclo claro/escuro de 11/11 horas, durante 8 semanas. O desenvolvimento tumoral ocorreu em 32 animais (82,05%), totalizando 73 tumores. A melatonina apresentou efeitos benéficos quanto a multiplicidade tumoral, grau histológico, tamanho dos tumores e peso dos animais, enquanto que a dessincronização não interferiu de forma significativa na carcinogênese mamária. / Breast cancer is the type of cancer that most affects women and the leading cause of death in the age between 40 and 55 years. Despite presenting international variation, their rates continue to increase worldwide, with up to five times more common in developed countries. The industrialization generates increased exposure to light at night, which causes suppression of melatonin. Melatonin is the main hormone secreted by the pineal gland and has oncostatic and antioxidant activity, interferes with cell cycle control, immune function and steroid hormones. The aim of this dissertation and present the rationale and development of the study whose objective was to evaluate the effect of melatonin therapy on the development of mammary tumors in rats exposed or not the circadian desynchronization. Induction of mammary carcinogenesis was via intragastric administration of DMBA in 39 Sprague- Dawley rats between 41 and 46 days. The animals were randomized into 04 groups, Synchronized and untreated, desynchronized and untreated, synchronized and with melatonin, desynchronized and with melatonin. Synchronized Groups were kept in a light / dark cycle of 12/12 hours and the desynchronized in a light / dark cycle of 11/11 hours for 8 weeks. The tumor development occurred in 32 animals (82.05%), totaling 73 tumors. Melatonin showed beneficial effects on tumor multiplicity, histological grade, tumor size and weight of the animals, while desynchronization did not interfere significantly in breast carcinogenesis.
223

Developing an oculomotor brain-computer interface and charactering its dynamic functional network

Jia, Nan 02 February 2018 (has links)
To date, invasive brain-computer interface (BCI) research has largely focused on replacing lost limb functions using signals from hand/arm areas of motor cortex. However, the oculomotor system may be better suited to BCI applications involving rapid serial selection from spatial targets, such as choosing from a set of possible words displayed on a computer screen in an augmentative and alternative communication application. First, we develop an intracortical oculomotor BCI based on the delayed saccade paradigm and demonstrate its feasibility to decode intended saccadic eye movement direction in primates. Using activity from three frontal cortical areas implicated in oculomotor production – dorsolateral prefrontal cortex, supplementary eye field, and frontal eye field – we could decode intended saccade direction in real time with high accuracy, particularly at contralateral locations. In a number of analyses in the decoding context, we investigated the amount of saccade-related information contained in different implant regions and in different neural measures. A novel neural measure using power in the 80-500 Hz band is proposed as the optimal signal for this BCI purpose. In the second part of this thesis, we characterize the interactions between the neural signals recorded from electrodes in these three implant areas. We employ a number of techniques to quantify the spectrotemporal dynamics in this complex network, and we describe the resulting functional connectivity patterns between the three implant regions in the context of eye-movement production. In addition, we compare and contrast the amount of saccade-related information present in the coupling strengths in the network, on both an electrode-to-electrode scale and an area-to-area scale. Different frequency bands stand out during different epochs of the task, and their information contents are distinct between implant regions. For example, the 13-30 Hz band stands out during the delay epoch, and the 8-12 Hz band is relevant during target and response epochs. This work extends the boundary of BCI research into the oculomotor domain, and invites potential applications by showing its feasibility. Furthermore, it elucidates the complex dynamics of the functional coupling underlying oculomotor production across multiple areas of frontal cortex.
224

Balada, canção e outros sons: um estudo fonoestilístico em Língua Portuguesa / Ballade, songs and others sounds: a phonostylistical study in Portuguese language

Sparano, Magalí Elisabete 24 March 2006 (has links)
Esta tese de doutorado apresenta como objetivo analisar a transformação que ocorre, no período clássico e no moderno, das formas: balada, canção, ode e soneto, da poesia em Língua Portuguesa, considerando os conceitos estabelecidos pela tradição poética. Essa transformação é observada sob o aspecto fonoestilístico, com ênfase na sonoridade que compõe os poemas: traços fonológicos, rimas, ritmo e metro. Destaque-se ainda que o foco será o estudo dessas características sonoras, a sua expressividade e como se desenvolve a combinação desses elementos, na constituição do(s) sentido(s), no interior dos poemas. / The present PhD thesis aims at analyzing the changes that occur in the classical and modern periods on some forms such as: ballade, song, ode and sonnet of the poetry in Portuguese. For this it was taken into consideration the established concepts which guide the poetry tradition. The transformation mentioned above is seen from the phonostylistics point of view with emphasis in the following sonority features, which constitute the poems: phonological traces, rhymes, rhythm and meter. It is relevant to mention that the focus given will be the study of such sonority features, the expressiveness presented by them and how the combinations of these elements are developed so as to achieve the constitution of the meaning(s) within the poems.
225

The Effects of Haptics on Rhythm Dance Game Performance and Enjoyment

Hodges, Bridger Scott 01 December 2018 (has links)
Haptics are an exciting, ever-expanding field, particularly in relation to video games. Though haptics found their way rather quickly into conventional games through devices like handheld controllers, music and rhythm titles have hardly seen such attention. Little research has been done to examine the effects of haptics on rhythm dance games from a quantitative and qualitative standpoint for the player. StepMania is an open-source dance game which closely mimics the popular title Dance Dance Revolution. This research investigates the effects of haptics on a sample size of fifty individuals. Each completed three songs in the game with varying conditions: the game's visuals only, a haptic device only, or both the haptics and visuals together. The haptic device warned the participant of an incoming step by vibrating two beats in advance in the direction needing to be stepped in. Music was present for all conditions, as it is an implied essential component of the game. Performance, self-reported enjoyment and self-reported difficulty were very similar between conditions involving visuals only and trials involving both the visuals and haptic device. Conditions involving the haptic device only (no visuals) saw a large drop in performance, a large increase in self-reported difficulty, and a very minor decrease in enjoyment. Despite the difference, participants reported enjoying the experience in free-response questions. The results of the study illustrate the potential for haptics to enhance user experience in rhythm dance video games. Additionally, these results indicate the beginnings of an avenue through which such dance games could become more accessible to the blind, who have been unable to participate in such games up to this point.
226

The Immediate Effect of Rhythm on the Timing of Upper Extremity Movements in Patients with Parkinson's Disease

Keenan, Erin Mary 01 June 2011 (has links)
Parkinson’s disease is a neurodegenerative disease caused by a loss of dopamine-producing neurons in the basal ganglia. Primary motor deficits include resting tremor, bradykinesia, muscular rigidity, and postural instability. Most importantly, patients have difficulty both initiating movements and performing well-timed movements. This study explored the effect of rhythm on the timing of upper extremity movements in patients with Parkinson’s disease. Comparisons were made between an external rhythmic cue, an external rhythmic cue in combination with auditory feedback, and no cue. Fifteen participants performed a simple reaching task in each of the four cueing conditions with the use of an interactive touch table. Condition 1 consisted of no cue. Condition 2 included a metronome set to the participant’s baseline tempo. Condition 3 included a metronome set to the participant’s baseline tempo, and a synthesized tone that occurred as a result of contact with the table. Finally, Condition 4 included no cue, similar to Condition 1. Participants were placed into either a mild/moderate level of impairment group, or a severe level of impairment group. Data were collected for total movement time, initiation time, and delta time for each participant in all four conditions. Results of the study did not reveal a main effect of condition on total movement time, initiation time or delta time. However, post-hoc pair-wise comparisons revealed significant decreases between Condition 1 and Condition 4, which were both uncued conditions, for both total movement time and delta time. In addition, for total movement time, a significant decrease was found between Condition 2 (external rhythmic cue) and Condition 4 (no cue). An immediate effect of cueing was found for initiation time and delta time, but did not reach a level of significance. An immediate effect of cueing on total movement time was not evident. Overall, from Condition 1 to Condition 2 as well as Condition 1 to Condition 3, initiation time and delta time decreased, but total movement time did not. Further analysis of level of impairment could not be conducted because of the small number of participants in the severe level of impairment group. The results suggest that one auditory cue was not more beneficial than the other for improving total movement time, initiation time, or delta time. In addition, the improvement from Condition 1 to Condition 4 for total movement time and delta time suggests that a practice effect was evident for the participants. The results of the study suggest that long-term training of either auditory cue can be an effective rehabilitation technique for patients with Parkinson’s disease to improve the timing of upper extremity movements.
227

Fibrinolytic Proteins and Brain-Derived Neurotrophic Factor Modulation of Suprachiasmatic Nucleus Circadian Clock

Mou, Xiang 01 August 2010 (has links)
Mammalian circadian rhythms are controlled by a clock located in the suprachiasmatic nucleus (SCN). The mechanisms through which light phase-shifts the SCN circadian clock are similar to those underlying memory formation and long-term potentiation (LTP). Several secreted proteins, including tissue-type plasminogen activator (tPA), plasminogen, and brain-derived neurotrophic factor (BDNF), have been implicated in this process. These same proteins are important for photic phase-shifts of the SCN circadian clock. Early night glutamate application to SCN containing brain slices resets the circadian clock. Our experiments find that the endogenous tPA inhibitor, plasminogen activator inhibitor 1(PAI-1), blocked these shifts in slices from wildtype mice but not mice lacking its stabilizing protein, vitronectin (VN). Plasmin, but not plasminogen, prevented inhibition by PAI-1. Both plasmin and active BDNF reversed alpha2-antiplasmin inhibition of glutamate-induced shifts. alpha2-Antiplasmin decreased the conversion of inactive to active BDNF in the SCN. Both tPA and BDNF allowed daytime glutamate-induced phase-resetting. Together, these data are the first to demonstrate expression of these proteases in the SCN, their involvement in modulating photic phase-shifts, and their activation of BDNF in the SCN, a potential ‘gating’ mechanism for photic phase-resetting. Using western-blot analyses of SCN tissue maintained in vitro, we find higher tPA, plasmin and mBDNF levels in the SCN at night vs. the day. Also, in vitro glutamate treatment of SCN tissue during early night increases tPA levels to ~2.5 times control levels, while similar treatments during late night and mid-day do not alter tPA expression. Glutamate treatment in the early night does not alter PAI-1, plasmin and BDNF levels. Co-treatment with glutamate and PAI-1 decreases plasmin levels (vs. glutamate treatment alone), while co-treatment with glutamate and alpha2-antiplasmin decreases the amount of pro- and mBDNF in the SCN relative to glutamate treatment alone. We also show that mBDNF levels are significantly lower in tPA knockout mice during both day and night. Together, these results support circadian clock modulation of BDNF and fibrinolytic protein levels in the SCN. They also suggest that glutamate modulates tPA expression in the SCN, while tPA and plasmin modulate BDNF expression.
228

Post Exercise Hypotension and Blood Pressure Circadan Rhythm in Pre-hypertensive Older Adults

Spragg, Carly Marie 15 February 2010 (has links)
Pre-hypertension (pre-HT) (Blood Pressure (BP) ≥120/80mmHg to ≤ 140/90mmHg) increases the risk of developing hypertension (HT). BP reductions following acute exercise are known as post exercise hypotension (PEH). BP and perhaps PEH shows a daily circadian rhythm. Purpose: To compare the magnitude of PEH after morning and evening aerobic exercise in adults with pre-HT. Hypothesis: The magnitude of PEH will be larger after evening versus morning exercise. Participants: Pre-HT men and women 50-65 years old. Study Design: Participants engaged in cycling exercise (60% VO2max) on two occasions: 1.5 and 11 hours following waking. Cardiovascular function was assessed for 30 minutes pre and one hour post exercise. Results: 1) Systolic PEH responses affected by TOD differed by gender. 2) Baseline Heart Rate Variability and its response to exercise differed gender but not TOD. The inconsistent significant gender and TOD differences of PEH and its mechanisms suggest that this group.
229

Music Processing in Deaf Adults with Cochlear Implants

Saindon, Mathieu R. 11 January 2011 (has links)
Cochlear implants (CIs) provide coarse representations of pitch, which are adequate for speech but not for music. Despite increasing interest in music processing by CI users, the available information is fragmentary. The present experiment attempted to fill this void by conducting a comprehensive assessment of music processing in adult CI users. CI users (n =6) and normally hearing (NH) controls (n = 12) were tested on several tasks involving melody and rhythm perception, recognition of familiar music, and emotion of recognition in speech and music. CI performance was substantially poorer than NH performance and at chance levels on pitch processing tasks. Performance was highly variable, however, with one individual achieving NH performance levels on some tasks, probably because of low-frequency residual hearing in his unimplanted ear. Future research with a larger sample of CI users can shed light on factors associated with good and poor music processing in this population.
230

Post Exercise Hypotension and Blood Pressure Circadan Rhythm in Pre-hypertensive Older Adults

Spragg, Carly Marie 15 February 2010 (has links)
Pre-hypertension (pre-HT) (Blood Pressure (BP) ≥120/80mmHg to ≤ 140/90mmHg) increases the risk of developing hypertension (HT). BP reductions following acute exercise are known as post exercise hypotension (PEH). BP and perhaps PEH shows a daily circadian rhythm. Purpose: To compare the magnitude of PEH after morning and evening aerobic exercise in adults with pre-HT. Hypothesis: The magnitude of PEH will be larger after evening versus morning exercise. Participants: Pre-HT men and women 50-65 years old. Study Design: Participants engaged in cycling exercise (60% VO2max) on two occasions: 1.5 and 11 hours following waking. Cardiovascular function was assessed for 30 minutes pre and one hour post exercise. Results: 1) Systolic PEH responses affected by TOD differed by gender. 2) Baseline Heart Rate Variability and its response to exercise differed gender but not TOD. The inconsistent significant gender and TOD differences of PEH and its mechanisms suggest that this group.

Page generated in 0.0466 seconds