Tactons are tactile cues, which work in conjunction with a vibrotactile device that is placed on the body, and mechanically produces sensations on the skin surface; this allows the sense of touch to be used in Human-Computer Interaction (HCI). Effective tacton parameters of stimuli have been identified for a young population. However, studies have shown that the detection of vibrations degrades as a natural part of the aging process. Furthermore, there are a variety of different vibrotactile devices, and studies have shown that vibrotactile device type can affect detection thresholds. This presents a challenge since detection thresholds and recognition rates of different tacton cues, using one device, may not correlate to those of another. There is limited research on the effectiveness of tacton parameters and detection thresholds of simple waveforms in an older population of computer users, when using the C2 Tactor from EAI systems. This work used the C2 Tactor and stimulus parameters similar to those which have been shown to be effective in a young population, and conducted a comparison study between a young population of computer users between 18 and 25 years old and an older population of computer users between 55 and 75 years old. The study compared both groups' detection thresholds of three different simple waveforms (sinusoidal, square, and sawtooth) and found a significant increase in detection threshold by the older group. In addition a comparison of both groups' recognition rates of modulated sinusoidal waveforms was conducted and it was found that the older group had a significant decrease in recognition rates of modulated sinusoidal waveforms. In addition, it was shown that increasing the amplitude significantly improved the recognition rate of the older test group. A significant amount of variance in detection threshold and tacton recognition rates was found in the older test group, particularly those over the age of 60. The results of this study clearly showed a correlation between age, detection threshold, and recognition rates of tactons. The study shows that detection threshold and recognition rate deficiencies of older adults are functions of frequency and amplitude and not waveform or device.

The continued decentralization of employment in U.S. regions has led to the emergence of large employment centers outside of traditional Central Business Districts. Edge Cities in particular, with their high office space densities, significantly influence surrounding land uses and regional commuting patterns. However, existing transit systems tend to be oriented to historic Central Business Districts and the level of service for transit in suburban areas remains considerably below that of central cities. Adequately serving suburban Edge Cities with transit is critical in maintaining and improving access to jobs by transit and mitigating automobile congestion. This study explores the suitability of a Bus Rapid Transit system along the Veterans Boulevard corridor in Greater New Orleans. It does this by analyzing residential and employment densities and existing commuting patterns along the corridor. It also explores the potential impact of BRT improvements on transit ridership in the corridor.

The environmental problems facing the world today are largely attributable to anthropogenic activities and landscape change. Addressing these challenges in an evidence-based way requires an understanding of precisely how species and ecosystems are responding to human impacts. Discerning linkages between stressors and their ecological repercussions, and using this to inform conservation, can be challenging due to the complexity and uncertainty of ecological research. I focused on the responses of five wide-ranging large mammal species – gray wolf (Canis lupus), Canada lynx (Lynx canadensis), coyote (Canis latrans), white-tailed deer (Odocoileus virginianus) and moose (Alces alces) – to human footprint (measure of human infrastructure and landscape change), using 12 years (2001-2013) of snowtrack surveys conducted across the boreal forest of Alberta. I explored three key challenges to discerning the linkages between ecological dynamics and management actions. First, I asked whether the direction and magnitude of species responses vary depending on the spatial extent and grain of the study. Second, I asked whether these species respond more strongly to individual footprint features or to the cumulative effects of footprint (measured as total footprint), and whether responses to footprint are consistent across species. Third, I evaluated the utility of thresholds for large mammal management and asked whether there is evidence for consistent threshold responses to total footprint across scales. In addressing the first two questions, I evaluated a set of generalized linear mixed effects models (GLMM) relating the relative abundance of each species to individual and cumulative effects of human footprint, using an information-theoretic approach. I compared the direction of species responses across our regional study area (approximately 400,000 km2) to those reported in previous smaller-extent studies (median 1,525 km2), and compared responses across three spatial grains (250m, 1500m, and 5000m transect buffers). In addressing the third question, I conducted a review on the utility of ecological thresholds, described as abrupt changes in the response to a continuous driver, for large mammal management. I further tested for thresholds in species responses to total footprint by comparing linear models (logistic regression) to piecewise regression models. I compared threshold values between two grains (approximately 33km2 - 1500m transect buffer, and 5500km2 - grouping transects into clusters), and across four regions (boreal forest extent, three landscape planning units). I found that the direction of species responses varied with spatial extent, but not grain, and that species responded strongly to a broad suite of footprint features, indicating the need to manage for cumulative effects. Despite the appeal of ecological thresholds, using these as targets is challenging and the success of doing so has rarely been evaluated. I found threshold models to be better supported than linear ones across species, but due to variability and uncertainty in threshold values, the results are more suited as guidelines or hypotheses to be further tested, as opposed to specific management targets. Translating research on complex ecological systems into management actions is a continuing challenge, yet, ongoing biodiversity monitoring and adaptive management may refine our existing tools, and ultimately lead to better environmental stewardship. / Graduate / 2017-09-05 / 0329

The Stenger Principle describes the observation that when two tones of the same frequency are presented simultaneously, a single tone is perceived only in the ear in which the tone is louder. This principle underlies the Stenger Test, which is used to identify the presence of unilateral nonorganic hearing loss (NOHL). Minimum contralateral interference levels (MCILs), which can be used to estimate true hearing thresholds in individuals with unilateral NOHL, are also based on this principle. In this study, the Stenger Principle is used to examine MCILs and the correspondence of the MCILs to true hearing thresholds in 16 adults with normal hearing. In Part I of the study, subjects were asked to feign a unilateral hearing loss. Average MCILs were 12.5, 15.1, and 13.5 dB HL for 1.0, 2.0, and 4.0 kHz, respectively. These were obtained with nearly equal interaural stimulus levels. The average difference between MCIL and true hearing threshold was 7.6, 9.7, and 8.9 dB, respectively. In Part II of this study, subjects were asked to make lateralization judgments for simultaneously presented tones with varying interaural intensity differences. Individual subject ratings were compared to MCILs obtained in Part I. Although most subjects showed the Stenger Effect with a midline percept of the two tones, variability between subjects existed. In some cases the Stenger Effect was not apparent until the tonal image was pulled nearly to the "poor" ear. Because of the potential differences in response bias (a client may show the Stenger Effect with a small shift in the tonal signal away from the "good" ear or may require the tonal signal to be fully lateralized to the "poor" ear), clinicians cannot predict exact hearing thresholds. Rather, it is useful to describe a range within which the true threshold will be. The 90% ranges (5th and 95th percentiles) calculated in this study were approximately 1 and 17 dB. That is, the MCILs for the majority of the subjects were within ~ 1 and 17 dB of true hearing thresholds.

Objective: Research on the role of acute post-surgical pain in children is extremely important in order to have a positive influence on pre-surgical preparation and post-surgical care and to prevent pain from becoming chronic, which can extend decades into adulthood. This project aims to identify predictors of acute post-surgical pain in adolescents with idiopathic scoliosis undergoing spinal fusion by utilizing sensory thresholds obtained through quantitative sensory testing (QST). Methods: Eligible candidates were Adolescent Idiopathic Scoliosis (AIS) patients ages 10-17 who have been recommended to receive elected spinal fusion surgery at Boston Children's Hospital (BCH). 9 successfully recruited and enrolled participants underwent a full series of QST tests on their palmar thenar eminence (non-surgical site), and their lower back (surgical site). Patients' Light Touch Detection Threshold (LTDT) and Pain Detection Threshold (PDT) scores were determined using Von Frey Hairs. Patients' Pressure-Pain Sensation Threshold (PPST) scores were determined using a pressure algometer. Patients' Warm/Cool and Hot/Cold Pain Detection Thresholds were detected using a calibrated thermode strapped to the skin. Following the full-series of QST tests, and after the patient was discharged from the hospital, a retrospective chart review was conducted to determine the patients': Age at Surgery, Gender, Number of Vertebrae Fused (Fusion Length), Length of Surgery, Pre-Operative Self-Identified Pain Level (NRS 0-10), Average Post-Operative Acute-Phase Self-Identified Pain Level (NRS 0-10), and daily Pain Medication Doses (Opiate Vs. Non-Opiate Vs. Total). Correlation calculations were done between each variable, including those determined through QST as well as retrospective chart review. For every QST test, each patient's individual score was compared to the cohort's median score, which helped determine whether the patient was either hyper- or hyposensitive for that particular test. For each QST test, these hyper- and hyposensitive groups were then compared to see if there were any significant differences in post-operative pain experienced. Results: Due to the low number of participants (N = 9), the results should be considered preliminary. Correlation studies demonstrate that pre-operative pain was significantly positively correlated with post-operative pain (r = 0.81, p <0.05), indicating that patients who are pre-operatively already in pain, will consequently experience the most pain post-operatively. Additionally, fusion length had a strong positive correlation to acute post-operative opiate pain medication administration (r = 0.71, P < 0.05), indicating that patients who had more vertebrae fused were given more opiates. Through the use of QST, we discovered that patients hypersensitive in the LTDT-Spine QST test experienced significantly less pain post-operatively (3.22 NRS 0-10) than that experienced by hyposensitive patients (5.52 NRS 0-10) from the same test. Identical results were discovered in patients determined hyper- and hyposensitive using the PPST-Spine test, respectively. Retrospective chart review data show that these hyposensitive patients were experiencing greater pain pre-operatively (0.75 NRS 0-10) than that experienced by the hypersensitive patients (0 NRS 0-10), which may have contributed to the hyposensitive cohort's greater post-operative pain. Although insignificant, patients hypersensitive in the Hot Pain - Spine QST test experienced greater post-operative pain (4.72 NRS 0-10) than that experienced by hyposensitive patients in the same test (4.06 NRS 0-10). Conclusions: The goal of this study was to determine a substantiated hypothesis to test in the future, using larger pediatric cohorts. Even though it initially appears that the hyposensitive patients, as determined by the LTDT-Spine and PPST-Spine QST tests, experienced greater post-operative pain, one must consider the fact that this hyposensitive group experienced a significantly greater amount of pre-operative pain. Not only has pre-operative pain been proven to have a strong correlation to post-operative pain in this study, it has also been proven in other larger studies as well. Other studies have identified a test similar to the Hot Pain - Spine QST test as a potential predictor of post-operative pain. The present study's results, although insignificant, share the same conclusion that hypersensitive patients determined through Hot Pain - Spine QST test experience greater post-operative pain. Therefore, the hypothesis to test in the future in pediatric cohorts should read: AIS patients with no pre-operative pain who demonstrate increased sensitivity to hot pain on their surgical site via thermal stimulation (QST) will experience greater post-operative pain in the acute-recovery phase.

Made available in DSpace on 2016-04-27T18:12:39Z (GMT). No. of bitstreams: 1 Roberta Robba Asola Fratti.pdf: 1045802 bytes, checksum: a3bb5045a43064f459393edbd811e6cf (MD5) Previous issue date: 2009-02-19 / Introduction: Despite technological advances currently available, the audiometric test tonal still represents the only test that evaluates the hearing in a range of frequencies. Due to cases of incompatibility of results in clinical practice is essential to conduct research using different stimuli during the tests. Objective: To compare PTA thresholds gotten with the warble and narrow band stimuli in subjects with sensorio-neural hearing loss, without and with tinnitus. Method: The audiometric thresholds by air conduction with the stimulus warble and narrow band were researched in the frequencies 250 to 8000Hz in both ears in three groups: subjects with normal hearing, with hearing loss and without tinnitus and with hearing loss and tinnitus. Results: The results demonstrated meaningful statistic differences between warble and narrow band in all of groups. In the comparative analysis, the differences had been higher, with significance statistics, in the groups with hearing loss when compared with the subjects with normal hearing, independently of the tinnitus. Conclusion: the use of different stimulus in the audiometric evaluation can represent an important strategy for attainment of trustworth thresholds, mainly in subjects with hearing losses / Introdução: Apesar dos avanços tecnológicos atualmente disponíveis, a audiometria tonal ainda representa o único teste de audição que avalia a acuidade auditiva em uma determinada faixa de freqüências. Devido aos casos de incompatibilidade dos resultados encontrados na prática clínica é fundamental a realização de pesquisas utilizando diferentes estímulos durante os testes. Objetivo: Comparar os limiares audiométricos obtidos com os estímulos warble e narrow band em sujeitos com perda auditiva sem e com a presença de zumbido. Método: Foi realizada a audiometria tonal liminar por via aérea com os estímulos warble e narrow band nas freqüências de 250 a 8000 Hz (Hertz) em ambas as orelhas em três grupos: normo-ouvintes, com perda auditiva e sem zumbido e com perda auditiva e com zumbido. Resultados: Os resultados encontrados mostraram diferenças estatisticamente significantes entre o warble e narrow band intragrupos. Na análise comparativa, as diferenças foram maiores, com significância estatística, nos grupos com perda auditiva quando comparados aos normo-ouvintes, independentemente da presença de zumbido. Conclusão: a utilização de diferentes estímulos na realização da avaliação audiométrica pode representar uma importante estratégia para obtenção de limiares fidedignos, principalmente em indivíduos com perdas auditivas

A abdominoplastia é uma das cirurgias plásticas mais realizadas. A associação entre a lipoaspiração e o descolamento reduzido trouxe uma nova perspectiva em relação à maior preservação da inervação cutânea sensitiva. Novos métodos de avaliação de sensibilidade têm permitido melhor quantificação e uma análise mais completa da evolução pós-operatória. Foi realizado um estudo do tipo caso-controle comparando-se um grupo controle de pacientes não operadas, um grupo de pacientes que realizou abdominoplastia convencional e um grupo que realizou abdominoplastia associada a lipoaspiração e descolamento reduzido. Para a avaliação da sensibilidade, utilizou-se o PSSD (dispositivo específico de sensibilidade de pressão), testes para sensibilidade térmica e dolorosa (agulhas). O PSSD foi aplicado em nove regiões da parede abdominal anterior para determinação do limiar cutâneo de pressão (LCP) em duas modalidades sensoriais: um ponto estático (1PE), para avaliação de fibras de adaptação lenta, e um teste dinâmico (1PD), para avaliação de fibras de adaptação rápida. Quanto maior o LCP, menor a sensibilidade na região. Foram incluídas 46 pacientes nos três grupos. O grupo controle continha 10 pacientes, cujos limiares cutâneos de pressão (LCP) variaram de 0,82 a 0,84 e de 0,77 a 0,79 g/mm2 para 1PE e 1PD, respectivamente. O grupo de abdominoplastia convencional (AC) continha 14 pacientes com medidas em dois momentos de pós-operatório, precoce (5,75 meses) e tardio (17,36 meses). Os resultados demonstraram LCPs entre 1,02 e 39,94 para a medida precoce e 0,79 e 20,07 g/mm2 para a medida tardia. O grupo de abdominoplastia associada a lipoaspiração (LA) continha 22 pacientes com acompanhamento de 5,72 meses (precoce) e 14,91 meses (tardio). Os resultados demonstraram LCPs entre 0,62 e 4,98 para a medida precoce e 0,67 e 1,91 g/mm2 para a medida tardia. A análise estatística usou método de análise de variância com medidas repetidas. O nível de significância adotado foi de 0,05. A análise estatística para a medida de 1PE revelou redução da sensibilidade significante no grupo AC em todas as regiões (precoce e tardia). No grupo LA, houve redução da sensibilidade apenas nas regiões de mesogastro e hipogastro na medida precoce com regularização total na análise tardia. Entretanto, a análise estatística para 1PD revelou, no grupo AC, redução na medida precoce em todas as regiões e redução apenas das regiões centrais (mesogastro e hipogastro) na análise tardia. Já no grupo LA, todas as medidas estavam normalizadas na análise precoce e tardia. A análise da sensibilidade térmica e dolorosa revelou reduções centrais, especialmente nas regiões de mesogastro e hipogastro no grupo AC. O grupo LA revelou áreas de anestesia térmica e dolorosa apenas em pequena área do hipogastro. Concluiu-se que as três modalidades sensoriais (tátil, térmica e dolorosa) são mais preservadas no grupo LA que no grupo AC. A recuperação da medida 1PD é mais rápida que a medida de 1PE / Abdominoplasties are common plastic surgery procedures. New techniques associating lipoaspiration with selective undermining are bringing new perspectives with regard to the preservation of cutaneous sensibility. New methods of evaluation of cutaneous sensibility have allowed researchers to do a more complete analysis. This is a case-control study comparing a control group of patients non operated with one group submitted to conventional abdominoplasty and another group submitted to abdominoplasty associating lipoaspiration with selective undermining. The abdominal surface was divided into nine regions for sensibility evaluation. Superficial tactile sensibility was tested using the Pressure Specified Sensory Device (PSSD) which allows the determination of the cutaneous pressure threshold (static and moving). Tests of pain and thermal sensibility were also performed. A total of 46 patients were divided in three groups. In the control group, with 10 patients, the cutaneous pressure thershold (CPT) oscilated from 0.82 to 0.84 and from 0.77 to 0.79 g/mm2 for one point static and one point moving sensibility evaluations, respectively. The group of patients submitted to conventional abdominoplasty (AC), with 14 patients, was evaluated in two moments of follow-up: early (mean of 5.75 months after surgical procedure) and late (17.36 months). The results showed CPTs betwen 1.02 and 39.94 in the early follow-up, versus 0.79 to 20.07 g/mm2 in the late follow-up. The group submitted to abdominoplasty associated with lipoaspiration and selective underminig (LA) had 22 patients, with a mean follow-up period of 5.75 (early) and 14.91 (late) months. The results showed CPTs betwen 0.62 and 4.98 (early) and 0.67 and 1.91 g/mm2 (late). The statistical analysis was conducted with the analysis of variance with repeated measurements. The level of significance adopted was p < 0.05. The estatistical analysis for one point static showed significant reduction of sensibility in the group AC in all abdominal regions (in the early and late follow-up periods). The group LA presented reduced CPT only in the mesogastric and hypogastric in the early evaluation; the late evaluation was normal. On the other hand, the analisis of one point moving showed, in the group AC, a reduction of early evaluation measurement in all abdominal regions and a reduction only in central regions (mesogastric and hypogastric) in the late. The LA group presented normal in all measurements. The analysis of pain and thermal sensibility shows that the centermost regions of the abdomen, mesogastric and hypogastric, presented the highest anesthesia index in the AC group. The LA group showed just some islands in the hipogastric regions. The recuperation of the 1PD evaluation was faster than the 1PE. In conclusion, the three sensibilities (tactile, thermal and pain) were more preservated in the LA group. Abdominoplasty with lipoaspiration could be considered a better choice than conventional abdominoplasty considering the preservation of cutaneous sensibility

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