Thesis (Ph. D.)--Indiana University, 2006. / Includes bibliographical references. Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (Ph. D.)--Indiana University, 2006. / Includes bibliographical references.

There has been accumulating scientific evidence, over the last three decades, of the role of inflammatory processes in the development of Alzheimer's disease (AD). Population based studies suggest that plasma levels of inflammatory markers are raised in peripheral blood of people with AD. People on long term use of non-steroidal anti-inflammatory drugs have a lower prevalence of AD. Moreover, both animal and human histopathology studies have reported localization of inflammation in brain areas primarily affected by AD pathology. Areas of increased inflammation can be visualized in vivo by Positron Emission Tomography (PET) scans using the PK11195 ligand that binds with the benzodiazepine receptor sites of activated microglial cells. Cognitive decline in AD has been shown to correlate with levels of microglial activation using PK11195 PET scans. People with amnestic mild cognitive impairment (MCI) are known to be at high risk of developing AD.We aimed to investigate the association between peripheral and central markers of inflammation and cognitive decline in a group of people with amnestic MCI.MCI subjects (n=70) underwent cognitive testing, IL-6 and CRP in peripheral blood were measured and repeated after 1 year. A sub group (n=15) was followed up for another year and central brain microglial activation was measured by PET using PK11195 along with cognitive and peripheral inflammatory marker measurement. The mean CRP and IL-6 levels of the cohort increased over one year but the rise was only significant for CRP. No association was detected between inflammatory markers levels and cognition as measured by a battery of cognitive instruments. Group comparisons of the PET cohort with healthy controls (n=5) showed increased PK11195 binding (mean binding potential) in frontal lobe, temporal lobe, parietal lobe, putamen, occipital lobes and significantly increased binding in posterior cingulate gyrus. This study, to our knowledge, is unique in studying makers of inflammation in amnestic MCI participants both in peripheral blood and brain. The results of this study, in the light of current literature, add to the importance of recognition of inflammatory processes in people at risk of developing AD. The results suggest that CRP levels rise significantly over time and are detectable in peripheral blood by using practically simple laboratory techniques. The results also suggest that activated microglia in amnestic MCI patients can be visualized in vivo by using PK11195 PET scans and show higher levels of activation as compared to healthy controls. These finding could be useful in identifying people with malactivated (pro-inflammatory) microglia as potential targets for prevention/early treatment strategies. Further studies with larger samples sizes and long term follow-up are needed to investigate whether these peripheral and central inflammatory markers could shed light on the aetiology of AD and be useful in monitoring disease progression.

As Ontario faces a major shift in demographics, it is anticipated that the number of community-dwelling people living with cognitive impairment will increase significantly. Occupational therapists (OTs) may play a key role in ensuring timely diagnosis and/or informing a comprehensive plan of care for this population by assessing and reporting on functional abilities. The purpose of this study was to explore the impact of an OT home assessment on diagnosis and plan of care for persons with Mild Cognitive Impairment (MCI) in a primary care Memory Clinic setting using a before and after design. A toolkit of clinical measures was developed to assess self-perception of occupational performance, instrumental activities of daily living (IADLs), falls risk and home safety. Thirty-one participants who had been assessed by a Memory Clinic team completed a one-hour OT home assessment focused on these attributes. A change in the plan of care was proposed for 24 of 31 participants (i.e., 77%) after the assessment findings were reviewed by the lead physicians of three Memory Clinic teams. Clinical information from an OT home assessment was used by the Memory Clinic teams to change follow-up visit times, plan diagnosis and/or medication review and initiate additional community supports for persons with MCI. Women in this sample were more likely than men to experience changes to their plan of care and were also at a higher falls risk as indicated by scores on a screening tool of this attribute. Several time sensitive issues were identified during the OT home assessment including falls risk, home safety issues and participant concern with driving ability. The addition of an OT home visit to an existing Memory Clinic Model has the potential to change the overall plan of care and to identify issues that may impact overall health and wellness, and the ability to live well at home. While the context for this study was an existing Memory Clinic Model in primary care, the findings have implications for older adults in any health setting who are experiencing cognitive changes. / Thesis / Master of Science Rehabilitation Science (MSc)

No description available.

No description available.

Thesis advisor: Elizabeth A. Kensinger / Although healthy young and older adults remember emotional information better than neutral, emotion does not confer the same benefit upon memory for those experiencing memory impairments due to Alzheimer's disease (AD). It is poorly understood at what stage of processing these deficits occur--are they due to declines in memory storage and retrieval processes, or to a decline in earlier stages of attention allocation, which then impact memory storage and retrieval? It remains an open question how attention and memory processes may interact in aging and age-related disease. The goal of this research was to examine the effects of aging on the neural mechanisms underlying selective memory for emotional information in visual scenes, and to compare memory between healthy older adults and patients with very early AD pathophysiological changes. Experiment 1 examined young and older adults' encoding-related neural activation associated with selective memory for emotional items within visual scenes and with successful memory for emotional items and the scene background. There were few regions showing significant interactions between age and memory for positive and negative scenes. In contrast, Experiment 2 showed that aging significantly affected the neural networks underlying selective emotional item memory and successful memory for emotional items and backgrounds. The results indicate that older adults require greater connectivity among prefrontal regions than young adults to encode all elements of a scene, rather than just encoding the emotional item. Experiment 3 showed that despite poorer memory overall, patients showing very early AD pathophysiological changes have relatively well preserved memory, especially for positive information. Dividing older adults' attention during encoding did not significantly alter their pattern of selective emotional item memory, suggesting that encoding of emotional items may be an easier or relatively automatic task compared to encoding of the background. In conclusion, there are significant age-related changes in the underlying neural networks, but not activation patterns, for selective memory for positive and negative scenes. Patients with early AD pathophysiological changes have impaired memory overall, however they may be able to recruit a similar neural network of prefrontal regions as healthy older adults for encoding of scenes with positive information. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Psychology.

Depression is associated with higher severity of memory disorders and has been shown to predict lower levels of cognitive functioning in those diagnosed with Mild Cognitive Impairment (MCI) or dementia. Yet, little is known about this association cross-culturally, particularly between Hispanics and European Americans. This study demonstrates that although levels of depression differed significantly across diagnostic group, Hispanics and European Americans were similar in levels of depression at each diagnosis. However, only for the European American group did depression levels predict lower scores in confrontational naming and semantic memory. Additionally, exploratory analyses of the entire sample demonstrated that lower depression predicted less likelihood of MCI or dementia diagnoses. This could indicate that there is a need for intervention and treatment of depression, in particular for later stages of MCI and dementia, that should be culturally catered to individual ethnicities. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Submitted by SABRINA SUELEN AMARAL null (sabrinasuelen_5@hotmail.com) on 2017-02-26T00:34:42Z No. of bitstreams: 1 Dissertação definitiva Sabrina S Amaral - Copia.pdf: 862726 bytes, checksum: ef97a1fa8d86f69f3436915d6d9a433d (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-03-07T13:47:33Z (GMT) No. of bitstreams: 1 amaral_ss_me_sjrp.pdf: 862726 bytes, checksum: ef97a1fa8d86f69f3436915d6d9a433d (MD5) / Made available in DSpace on 2017-03-07T13:47:33Z (GMT). No. of bitstreams: 1 amaral_ss_me_sjrp.pdf: 862726 bytes, checksum: ef97a1fa8d86f69f3436915d6d9a433d (MD5) Previous issue date: 2017-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho analisamos as equações de Navier-Stokes em R^n, (n≤3) e mostramos boa colocação global, quando a velocidade inicial pertence ao espaço de Morrey e tem norma suficientemente pequena. Mostramos, também, que se o dado inicial é uma função homogênea de grau -1 então as soluções mild são autossimilares. Além disso, apresentamos um resultado de estabilidade assintótica das soluções mild. / In this work we will analyze the Navier-Stokes equations in R^n, (n≤3) and we will show global well-posedness, when the initial velocity belongs to the Morrey space and with a sufficiently small norm. We will also show that if the initial data is a homogeneous function of degree -1, then the mild solutions are self-similar. Moreover, we will present an asymptotic stability result of the mild solutions.

Moderate or Intense Low-oxygen Dilution (MILD) combustion is a combustion technology that can simultaneously improve the energy efficiency and reduce the pollutant emissions of combustion devices. It is characterised by highly preheated reactants and a small temperature rise during combustion due to the large dilution of the reactant mixture with products of combustion. These conditions are generally achieved using exhaust gas recirculation. However, the physical understanding of MILD combustion remains limited which prevents its more widely spread use. In this thesis, Direct Numerical Simulation (DNS) is used to study turbulence, premixed flames and MILD combustion to obtain these additional physical insights. In a first stage, the scale-locality of the energy cascade is analysed by applying a multiscale analysis methodology, called the bandpass filter method, on DNS of homogeneous isotropic turbulence. Evidence supporting this scale-locality were obtained and the results were found to be similar for Reynolds numbers ranging from 37 to 1131. Using the same method in turbulent premixed flames, the scale-locality of the energy cascade was still observed despite the presence of intense reactions. In addition, it was found that eddies of scales larger than the laminar flame thickness were imparting the most strain on the flame. In a second part, a methodology was developed to conduct the DNS of MILD combustion with mixture fraction variations. This methodology included the effect of mixing of exhaust gases with fuel and oxidiser in unburnt, burnt and reacting states. In addition, a specific chemical mechanism that includes the chemistry of ${\rm OH^*}$ was developed. From these DNS, the role of radicals on the inception of MILD combustion was studied. In particular, due to the reactions initiated by these radicals, the initial temperature rise in MILD combustion was occurring concurrently with an increase in the scalar dissipation rate of mixture fraction which is contrasting to conventional combustion. The reaction zones in MILD combustion were also analysed and extremely convoluted reaction zones were observed with frequent interactions among them. These interactions yielded the appearance of volumetrically distributed reactions. Furthermore, the adequacy of some species to identify these reaction zones was assessed and ${\rm OH}$ showed a poor correlation with regions of heat release. On the other hand, ${\rm OH^*}$, ${\rm HCO}$ or ${\rm OH} \times {\rm CH_2O}$ were found to be well correlated. Through the study of the flame index, the existence of non-premixed and premixed modes of combustion were also highlighted. The premixed mode was observed to be dominant but the contribution of the non-premixed mode to the total heat release was non negligible. Because of the presence of radicals and high reactant temperatures, auto-igniting regions and propagating reaction zones are both observed locally. The balance between these phenomena was investigated and it was found that this was strongly influenced by the typical lengthscale of the mixture fraction field, with a smaller lengthscale favouring sequential autoignition. Finally, using the bandpass filtering method, the effect of heat release rate in MILD combustion on the energy cascade was studied and this showed that the energy cascade was not unduly affected.