Signal processing of microstructure profiles: integrating turbulent spatial scales in aquatic ecological modeling

The main objective of this thesis was the integration of microstructure information in synoptic descriptors of turbulence, that reflects the mixing processes. Turbulent patches are intermittent in space and time, but they represent the dominant process for mixing. In this work, the properties of turbulent patches were considered the potential input for integrating the physical microscale measurements. The development of a method for integrating the properties of the turbulent patches required solving three main questions: a) how can we detect the turbulent patches from he microstructure measurements?; b) which are the most relevant properties of the turbulent patches?; and ) once an interval of time has been selected, what kind of synoptic parameters could better reflect the occurrence and properties of the turbulent patches? The answers to these questions were the final specific objectives of this thesis.

Imagem por ressonância magnética da vasculatura da pele humana : viabilidade no contexto clínico

Imagiologia por Ressonância Magnética (IRM) é uma modalidade de imagem médica que está a recuperar o interesse como uma técnica não invasiva no estudo da pele. Tipicamente campos magnéticos de elevada densidade e quipamentos específicos são usados. Este facto limita o usos da técnica a laboratórios e centros de investigação especializados. Neste trabalho estudou-se a viabilidade do uso da IRM no estudo da pele e da sua vasculatura usando equipamento convencional disponível em contexto clínico. Sequências IRM para imagem estrutural e veascular foram optimizadas e testadas para obtenção de imagens da pele do punho de 6 voluntários saudáveis. As sequências observáveis dos vasos, razão sinal-ruído, e razão contraste-ruído. Foi observado que duas sequências volumétricas baseadas em eco de gradiente e com ponderações T1 e T2 forneciam informação complementar em respeito à vasculatura da pele com resoluções espaciais da ordem dos micrómetros, podendo ainda esta informação ser fundida com imagens estruturais das cadamas da pele. Foi igualmente observado que estas sequências fornecem informação útil usando equipamento convencional e perspectiva-se a sua utilização no estudo das vasculatura de tumores cutâneos e na doença vascular periférica.

Strial capillary permeability following noise exposure in mice

A study of strial capillary permeability using fluorescent microspheres and immunohistochemistry in mice that do or do not exhibit a reduction in endocochlear potential following a single, intense noise exposure.

Development of curriculum in noise awareness

This paper presents a curriculum in noise awareness developed for use in the second and fourth grades, to teach children about the harmful effects of elevated noise levels.

Speech intelligibility in noise-induced hearing loss: effects of high-frequency compensation

This dissertation examines the frequency response that results in the maximum level of speech intelligibility for persons with noise-induced hearing loss.

Noise exposure in the operating room

This paper discusses a study done to determine noise levels in operating rooms

A comparison of physical measurements of pure-tones, third-octave bands of noise and third-octave bands of speech to subjective judgments of audibility threshold, MCL and UCL for three normally hearing listeners

This study investigates the relation between physical measurements of pure-tones, third-octave bands of noise and third-octave bands of speech and subjective judgments of auditory threshold, most-comfortable listening level (MCL) and uncomfortable-listening level (UCL) for three normally hearing listeners.

Noise levels and hearing conservation in a water treatment facility

This paper describes a study assessing the sound levels and noise exposures of a municipal water treatment plant to determine the level of employee noise exposure dosages and to make any necessary recommendations regarding reducing the risk of noise induced hearing loss in employees.

Evaluating the directional effects of acoustic horn style hearing aids using the QuickSIN procedure

This paper evaluates the directional effects of two hearing devices – an antique London Dome horn style device and a constructed Cupped Hand. The comparisons were made using the Quick SIN (Speech in Noise) adaptive test which measures signal-to-noise ratio loss.

Role of alpha synuclein in noise induced hearing loss

The recent discovery of the contribution of alpha synuclein in the auditory system prompted further investigation of its functional role. Auditory brainstem response (ABR) and gap detection testing were completed on wild-type and transgenic M83 mice to assess the role of alpha synuclein in noise-induced hearing loss and central auditory function.

The effectiveness of noise cancellation headphones for hearing impaired listeners

This paper discusses the use of noise cancellation headphones for hearing aid users to reduce background noise in order to improve speech discrimination.

Bone-conducted tones masked by air-conducted noise

This paper presents a study designed to develop and evaluate a method for obtaining monaural thresholds for bone-conducted signals masked by air-conducted noises.

Are distortion levels a problem with digital signal processing hearing aids and frequency modulation (FM) systems?

The purpose of this study was to examine objective and subjective distortion present when frequency modulation (FM) systems were coupled with four digital signal processing (DSP) hearing aids. Electroacoustic analysis and subjective listening tests by experienced audiologists revealed that distortion levels varied across hearing aids and channels.

Noise exposure in the fire department

This paper discusses noise exposure to firefighters on the job and whether this contributes to noise induced hearing loss.

Differences in performance in noise between conventional hearing aids and radiant multimicrophone beamforming technology

This paper discusses the results of a study to determine the differences between hearing aids and radiant beamforming technology.