Polarized light has the ability to increase the specificity of the investigation of biomedical samples and is finding greater utilization in the fields of medical diagnostics, sensing, and measurement. In particular, this dissertation focuses on the application of polarized light to address a major obstacle in the development of an optical based polarimetric non-invasive glucose detector that has the potential to improve the quality of life and prolong the life expectancy of the millions of people afflicted with the disease diabetes mellitus. By achieving the mapping of the relative variations in rabbit corneal birefringence, it is hoped that the understanding of the results contained herein will facilitate the development of techniques to eliminate the effects of changing corneal birefringence on polarimetric glucose measurement through the aqueous humor of the eye. This dissertation also focuses on the application of polarized light to address a major downside of cardiovascular biomechanics research, which is the utilization of toxic chemicals to prepare samples for histological examination. To this end, a polarization microscopy image processing technique is applied to non-stained cardiovascular samples as a means to eliminate, for certain cardiac samples, the necessity for staining using toxic chemicals. The results from this work have the potential to encourage more investigators to join the field of cardiac biomechanics, which studies the remodeling processes responsible for cardiovascular diseases such as myocardial infarct (heart attacks) and congestive heart failure. Cardiovascular disease is epidemic, particularly amongst the population group older than 65 years, and the number of people affected by this disease is expected to increase appreciably as the baby boomer generation transitions into this older, high risk population group. A better understanding of the responsible mechanisms for cardiac tissue remodeling will facilitate the development of better prevention and treatment regimens by improving the early detection and diagnosis of this disease.

Anodal transcranial direct current stimulation (tDCS) is an intervention which is thought to enhance motor learning in healthy and stroke-injured states, when applied adjunctively during skill learning. We set out to investigate whether anodal tDCS might enhance functional rehabilitation from incomplete tetraplegic SCI. To address current limitations in the measurement of task-dependent skill, a novel integrated skill training and measurement task, the Motor Skill Rehabilitation Task (MSRT) was designed and developed. Measures of performance from this task delivered the functional measure of spatial motor skill learning, Task Productivity Rate (TPR). TPR was analysed and validated as a univariate dependent outcome, which is of potential importance to the future development of clinical measures measuring goal-directed motor skills. The MSRT was included alongside conventional behavioural measures in a repeated-measures RCT pilot study, the first to investigate the effect of anodal tDCS on rehabilitation of motor skill from chronic spinal cord injury. Adjunctive application of anodal tDCS had a statistically significant benefit upon retention of skill in the incomplete spinal cord injured population, but only when the independent factor of sensory acuity was included in the analysis. Differences between the development of task-dependent skill and generic dexterity over time suggested that spatial skill development was subject to an interaction of short-term and lasting effects. A larger study in healthy persons further investigated these phenomena, also applying Transcranial Magnetic Stimulation (TMS)–evoked measurements to investigate intervention-dependent effects upon the excitability of projections between the primary motor cortex and muscles involved in the prehension task. The findings revealed that active tDCS did not enhance skill learning at 7 days beyond the training period, but did significantly alter the development of motor skill following a period of learning and subsequent skill consolidation which was associated with underlying perturbation of motor control strategy. Significant and divergent patterns of cortical plasticity were evoked in projections to muscles necessary for reaching and grasping. The main findings of this thesis do not support anodal tDCS as an effective adjunctive means of enhancing spatial motor skill in rehabilitation from incomplete tetraplegic SCI. If applied in patient populations, the clinical benefits of anodal tDCS may be contingent both on the nature of the sensorimotor deficit affecting upper limb function and the spatial demands of the behavioural task. The findings of this project serve to inform further research in relation to the effect of anodal tDCS on the brain and behavioural outcomes, the potential for efficacy in target patient groups and the sensitivity of outcome measures to spatial and temporal dimensions of practical motor skills.

This study looked at the efficacy of using woodland caribou fecal pellets as a source of DNA to identify sampled animals and estimate population demographics. Fecal pellet samples were collected using systematic surveys of woodland caribou ranges in Jasper National Park, Alberta and the North Interlake region, Manitoba. Collection of pellet samples took place when snow was present to allow for tracking and location of caribou cratering areas and to obtain good quality DNA. DNA was amplified at ten polymorphic loci and one sex-specific primer. To estimate population size (N ̂) and population growth rate (λ), mark-recapture models were used. Model assumptions were evaluated and tested by stratifying available samples based on herd and gender information. In using the Mh (jackknife) model, the population sizes for south Jasper National Park were estimated at 125 animals in 2006-2007 (95% CI: 114, 143), 91 animals in 2007-2008 (95% CI: 83, 105) and 134 animals in 2008-2009 (95% CI: 123, 152); comparable to the mark-resight population estimates calculated over the same sampling periods. Genetic diversity indices for the different herds in Jasper National Park presented a lower genetic diversity for the smaller Maligne and Brazeau herds when compared to the larger Tonquin and A La Peche herds. Use of population assignment tests on samples collected in Jasper National Park indicated considerable admixture between the different herds despite earlier telemetry work demonstrating strong herd fidelity. The North Interlake population was estimated at 134 animals (95% CI: 122,151) in 2006-2007 and 106 animals (95% CI: 97, 121) in 2007-2008. Using data collected between 2005 and 2008, population growth rate for North Interlake was estimated at 0.83 (90% confidence interval: 0.65, 1.02). As a λ below 1 indicates a declining population, continue monitoring of the North Interlake herd is highly recommended. This studied clearly showed that the sampling of fecal DNA is a reliable and noninvasive alternative to monitoring woodland caribou population sizes and trends in the boreal and mountain regions.

Molecular techniques, particularly noninvasive genetic sampling (NGS) and nondestructive sampling (NDS), are increasingly being used as tools to study the ecology of free-ranging mammals. A specific application of these methods is the molecular sexing of species for which external sex differentiation is challenging. Star-nosed moles (Condylura cristata) are a little-studied species in which females possess a peniform clitoris making them externally indistinguishable from males. To my knowledge, no studies have employed NDS to study any aspect of their ecology. I therefore sequenced fragments of one X-chromosome (Zfx) and two Y-chromosome (Sry and Zfy) genes from known-sex specimens, and designed species-specific primers to co-amplify these loci from hair, claw and fecal samples of 16 star-nosed moles. I found all tissue types were highly (90-100%) reliable for sex determination. I envision that this NDS method will facilitate future capture-and-release studies on the natural history and social structure of this fascinating, semi-aquatic mammal.

This study looked at the efficacy of using woodland caribou fecal pellets as a source of DNA to identify sampled animals and estimate population demographics. Fecal pellet samples were collected using systematic surveys of woodland caribou ranges in Jasper National Park, Alberta and the North Interlake region, Manitoba. Collection of pellet samples took place when snow was present to allow for tracking and location of caribou cratering areas and to obtain good quality DNA. DNA was amplified at ten polymorphic loci and one sex-specific primer. To estimate population size (N ̂) and population growth rate (λ), mark-recapture models were used. Model assumptions were evaluated and tested by stratifying available samples based on herd and gender information. In using the Mh (jackknife) model, the population sizes for south Jasper National Park were estimated at 125 animals in 2006-2007 (95% CI: 114, 143), 91 animals in 2007-2008 (95% CI: 83, 105) and 134 animals in 2008-2009 (95% CI: 123, 152); comparable to the mark-resight population estimates calculated over the same sampling periods. Genetic diversity indices for the different herds in Jasper National Park presented a lower genetic diversity for the smaller Maligne and Brazeau herds when compared to the larger Tonquin and A La Peche herds. Use of population assignment tests on samples collected in Jasper National Park indicated considerable admixture between the different herds despite earlier telemetry work demonstrating strong herd fidelity. The North Interlake population was estimated at 134 animals (95% CI: 122,151) in 2006-2007 and 106 animals (95% CI: 97, 121) in 2007-2008. Using data collected between 2005 and 2008, population growth rate for North Interlake was estimated at 0.83 (90% confidence interval: 0.65, 1.02). As a λ below 1 indicates a declining population, continue monitoring of the North Interlake herd is highly recommended. This studied clearly showed that the sampling of fecal DNA is a reliable and noninvasive alternative to monitoring woodland caribou population sizes and trends in the boreal and mountain regions.

Resumo: A constante ameaça às populações de veado-campeiro (Ozotoceros bezoarticus) faz deste cervídeo uma espécie ameaçada de extinção, trazendo à tona uma necessidade eminente de mais estudos, principalmente relacionado à biologia e fisiologia reprodutiva. Sendo assim, os objetivos deste trabalho foram: definir o padrão de excreção de progestágenos fecais durante a gestação do veado-campeiro e validar possível método não-invasivo para diagnóstico de gestação da espécie, com uso de análises endócrinas. Para isso, onze fêmeas da espécie foram capturadas, marcadas e receberam colares radiotransmissores no Pantanal, região da Nhecolândia. Elas foram acompanhadas mensalmente e tiveram sua fezes colhidas para caracterização hormonal da gestação, entre o período de agosto de 2008 a novembro de 2009. Foi observada a ocorrência de parto em apenas sete fêmeas, as quais foram utilizadas na caracterização endócrina da gestação. As dosagens das progestinas fecais foram feitas por ensaio imunoenzimático. Os nascimentos observados ocorreram entre agosto e outubro, com pico entre agosto e setembro. Os níveis das progestinas fecais durante o início da gestação foram semelhantes aos períodos não-gestantes, com aumento progressivo a partir do segundo terço da gestação até o momento do parto, decaindo após esse período aos níveis não-gestantes. Os níveis de progestinas fecais acima de 6000 ng/g de fezes são sugestivos de gestação. / Abstract: The constant risk of pampas deer populations (Ozotoceros bezoarticus) makes these threatened specie, bringing an eminent necessity of more studies, mainly related to biology and reproductive physiology. Being thus, the objectives of this work were: obtain the profile of fecal progestins excretion during the pampas deer gestation and to validate a possible noninvasive diagnosis method of gestation for the species, using endocrine analysis. For this, eleven females had been captured, marked and received necklaces radiotransmitters in Pantanal, region of Nhecolândia. They had been followed and their excrements were collected monthly for hormonal characterization between August, 2008 - November, 2009. Was observed the occurrence of birth in only seven females, which had been used in the endocrine characterization of gestation. The levels of fecal progestins during the beginning of gestation had been similar to those at nogestational periods, with gradual increase from the second part of gestation until the moment of birth, decaying after this period to no-gestation levels. The levels of fecal progestins above 6000 ng/g of excrements are suggestive of gestation. / Orientador: José Maurício Barbanti Duarte / Coorientador: Ubiratan Piovezan / Banca: Paulo Henrique Franceschini / Banca: Rosana Nogueira de Morais / Mestre

Les maladies chroniques du foie constituent un problème majeur de santé publique. L’évaluation précise du degré de fibrose hépatique apporte au clinicien une estimation du pronostic dès la prise en charge initiale de ces patients, mais permet également la réalisation d’une surveillance évolutive, et intervient dans la décision et le choix d’un traitement. L’évaluation noninvasive de la fibrose hépatique par élastographie a permis de révolutionner la prise en charge des malades atteints d’une maladie chronique du foie. L’objectif de notre travail est d’évaluer les performances diagnostiques d’une nouvelle technique d’élastographie hépatique, appelée « Supersonic ShearImaging » (SSI), et d’analyser sa plus-value dans l’évaluation non-invasive des maladies chroniques du foie.Dans une première étude, nous avons prospectivement analysé et comparé les performances diagnostiques de l’élastographie SSI par rapport au FibroScan et l’ARFI pour le staging de la fibrose hépatique sur une série de 349 patients avec une maladie chronique du foie diagnostiquée et gradée par ponction-biopsiehépatique.Dans une seconde étude, nous avons prospectivement étudié l’impact diagnostique de l’élastographie SSIsur le foie et la rate chez une population de 401 patients avec cirrhose pour l’évaluation de la gravité de la maladie cirrhotique.Dans une troisième étude, nous avons réalisé une analyse prospective bicentrique (Angers et Bordeaux)de la performance diagnostique de l’élastographie SSI par rapport au FibroScan et l’ARFI dans l’évaluation non invasive de la fibrose hépatique sur une série de 291 patients avec stéatopathie non-alcoolique et ponction-biopsiehépatique. / Abstract :The management and the prognosis for chronic liver diseases are widely based on the presence and the development of a liver fibrosis. The progressive worsening of liver fibrosis leads in a certain number of patients to the development of cirrhosis and its complications. Thus, the development of non-invasive diagnostic tools for the diagnosis and the monitoring of the liver fibrosis is of crucial interest. Liver elastography is one of the most promising techniques that have recently emerged in the field of chronic liver diseases. In this study, we aim to assess the diagnostic accuracy of a new elastography technique, named “Supersonic Shear Imaging” (SSI), and toanalyse its added value in the non invasive diagnosis of chronic liver diseases.In a first study, we prospectively analysed and compared the diagnostic performances of SSI elastography versus FibroScan and ARFI for the staging of liver fibrosis in a cohort of 349 patients with chronic liver diseases that consecutively underwent a liver biopsy. In a second study, we prospectively analysed the impact of liver and spleen SSI elastography in a cohortof 401 cirrhotic patients for the non invasive diagnosis of cirrhosis severity and oesophageal varices.In a third study, we assessed the clinical use of liver stiffness measurement evaluated by SSI, FibroScan,and ARFI in a cohort of nonalcoholic fatty liver disease patients who underwent liver biopsy. A total of 291 NAFLD patients were prospectively enrolled at 2 French university hospitals (Angers and Bordeaux).

No description available.

Cougars (Puma concolor) are difficult to census due to their large home ranges, low densities, and cryptic nature. The conventional “gold-standard” method for estimating cougar abundance entails the capture and radio-tagging of individuals in a study area in an attempt to acquire a direct enumeration of animals in the population. While this method provides an accurate abundance estimate, it is logistically challenging and prohibitively expensive. Noninvasive survey techniques may offer the ability to both accurately and inexpensively monitor cougar populations. While noninvasive techniques have been used on cougar populations, there remain questions on their accuracy and comparative efficacy. We estimated the density of a cougar population in Northwest Wyoming using direct enumeration, and used this estimate as a reference with which to evaluate the accuracy and cost-effectiveness of three types of noninvasive surveys performed between 2010 and 2014. The noninvasive methods included two annual mark- recapture sessions of: 1) remote camera trapping, 2) winter hair-collection transects, and 3) scat detection dog surveys. We GPS tracked 13 adult cougars (males = 5, females = 8) over 3 annual periods (Sep 2010 – Sep 2013). We used proportional home range overlap to determine density in a 1,570 km2 area. The average density was 0.82 cougars/100 km2 (± 0.10 SD; n = 3 years). The remote camera surveys produced a mean density of 0.60 cougars/100 km2 (n = 2 years; relative SD = 56.5%). The scat detection dog surveys produced an average density of 2.41 cougars/100 km2 (n = 2 years; relative SD = 12.6%). The winter transects failed to produce a sample size large enough for an abundance estimate. Due to the inclusion of non-adults in the scat sampling, and the fact that the reference estimate was essentially a minimum count of adults, we believe that the scat-based estimate was more accurate than the lower estimate produced by remote cameras. Additional analysis indicated that individual identification of cougars in photographs may not be reliable, challenging the validity of photo-based abundance estimates of cougars. On a cost-per-detection basis, scat detection dogs were the most cost effective method (scat detection dogs = $341; remote cameras = $3,241; winter transects = $7,627).

No description available.