955 resultados para aging process


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This paper aims to look at the teaching situation of the nursing undergraduate degree’s courses about eldercare in Portugal. A documentary research on the teaching programs in 39 nursing schools, 26 schools presented syllabus units related to the topic ‘eldercare’ and in eight of these schools the contents of the units were identified. Using textual analysis and from the categories we concluded that the teaching regarding eldercare for the nurse training in Portugal is focused on hospital care; it is directed to the adult/elderly/family; it explores the definitions related to the aging process; it explores community issues, legislation and research. People responsible for the design/monitoring of teaching programs should include teaching regarding eldercare in the nurse training, considering that the elder population is increasing in Portugal.

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The work reported in this thesis aimed at applying the methodology known as metabonomics to the detailed study of a particular type of beer and its quality control, with basis on the use of multivariate analysis (MVA) to extract meaningful information from given analytical data sets. In Chapter 1, a detailed description of beer is given considering the brewing process, main characteristics and typical composition of beer, beer stability and the commonly used analytical techniques for beer analysis. The fundamentals of the analytical methods employed here, namely nuclear magnetic resonance (NMR) spectroscopy, gas-chromatography-mass spectrometry (GC-MS) and mid-infrared (MIR) spectroscopy, together with the description of the metabonomics methodology are described shortly in Chapter 2. In Chapter 3, the application of high resolution NMR to characterize the chemical composition of a lager beer is described. The 1H NMR spectrum obtained by direct analysis of beer show a high degree of complexity, confirming the great potential of NMR spectroscopy for the detection of a wide variety of families of compounds, in a single run. Spectral assignment was carried out by 2D NMR, resulting in the identification of about 40 compounds, including alcohols, amino acids, organic acids, nucleosides and sugars. In a second part of Chapter 3, the compositional variability of beer was assessed. For that purpose, metabonomics was applied to 1H NMR data (NMR/MVA) to evaluate beer variability between beers from the same brand (lager), produced nationally but differing in brewing site and date of production. Differences between brewing sites and/or dates were observed, reflecting compositional differences related to particular processing steps, including mashing, fermentation and maturation. Chapter 4 describes the quantification of organic acids in beer by NMR, using different quantitative methods: direct integration of NMR signals (vs. internal reference or vs. an external electronic reference, ERETIC method) and by quantitative statistical methods (using the partial least squares (PLS) regression) were developed and compared. PLS1 regression models were built using different quantitative methods as reference: capillary electrophoresis with direct and indirect detection and enzymatic essays. It was found that NMR integration results generally agree with those obtained by the best performance PLS models, although some overestimation for malic and pyruvic acids and an apparent underestimation for citric acid were observed. Finally, Chapter 5 describes metabonomic studies performed to better understand the forced aging (18 days, at 45 ºC) beer process. The aging process of lager beer was followed by i) NMR, ii) GC-MS, and iii) MIR spectroscopy. MVA methods of each analytical data set revealed clear separation between different aging days for both NMR and GC-MS data, enabling the identification of compounds closely related with the aging process: 5-hydroxymethylfurfural (5-HMF), organic acids, γ-amino butyric acid (GABA), proline and the ratio linear/branched dextrins (NMR domain) and 5-HMF, furfural, diethyl succinate and phenylacetaldehyde (known aging markers) and, for the first time, 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one xii (DDMP) and maltoxazine (by GC-MS domain). For MIR/MVA, no aging trend could be measured, the results reflecting the need of further experimental optimizations. Data correlation between NMR and GC-MS data was performed by outer product analysis (OPA) and statistical heterospectroscopy (SHY) methodologies, enabling the identification of further compounds (11 compounds, 5 of each are still unassigned) highly related with the aging process. Data correlation between sensory characteristics and NMR and GC-MS was also assessed through PLS1 regression models using the sensory response as reference. The results obtained showed good relationships between analytical data response and sensory response, particularly for the aromatic region of the NMR spectra and for GC-MS data (r > 0.89). However, the prediction power of all built PLS1 regression models was relatively low, possibly reflecting the low number of samples/tasters employed, an aspect to improve in future studies.

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All the evidence indicates that distillation and liqueurs preparation began in Monchique mountain because this place was pointed as a possible capital of the oldest population of Algarve and an important Arabic village (Barreto, 1972: 19). It was possible to find lots of vestiges like the alembic produced by Arabic population near the X century (Telo, 1988: 77). Traditionally the Algarvian people produce the Arbutus unedo L., fig, carob, grape distillates. At the same time they produce liqueur-using maceration of parts of plants or fruits in some kinds of distillates. Most of the work about Algarvian distillates started by studying the basic compounds of Arbutus unedo spirits by gas chromatography (GC) and mass spectrometry (MS) as well as other physical-chemical properties. In a second phase aged distillates were studied by their phenolic compounds evolution using high resolution liquid chromatography (HPLC). Volatile compounds of traditional liqueurs were identified by head space micro extraction solid phase (HE-SPME) and also analysed by gas chromatography mass spectrometry (GC-MS) and when possible confirmed with standards. Total phenols were determined by Folin-Ciocalteur method. Flavenoids were studied by high performance liquid chromatography (HPLC). Sensorial analysis was also done in every drink studies. The results showed that the arbutus distillate doesn’t present a high level of methanol according to the current legislation. The excesses of acidity or ethyl acetate present normal values when the fermentation is well done (Galego, et al. 1995: 341; Galego, et al. 1995: 685). During the aging process, the colour of spirits tend to become darker, the colour changes occurred more rapidly in the arbutus spirits located in cellars with higher temperatures (Galego, et al. 2001: 432). In the sensory evaluation of samples aged during 12 months into 50 L medium toasting level oak wood barrels, panellists considered that samples of arbutus spirit had too much wood flavour and they were not able to detect the characteristic aroma of arbutus fruit (Galego, et al., 2001: 183). Differences in liqueurs were observed using HS-SPME-GC, HS-SPME-GC-MS or HPLC analysis and this observation was confirmed by a sensorial panel (Galego, et al. 2003: 60).

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Tese de doutoramento, Enfermagem, Universidade de Lisboa, com a participação da Escola Superior de Enfermagem, 2014

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Tese de doutoramento, Ciências Biomédicas (Bioquímica Médica), Universidade de Lisboa, Faculdade de Medicina, 2014

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Dissertação de Mestrado, Tecnologia e Segurança Alimentar, 02 de Junho de 2014, Universidade dos Açores.

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Introdução: A correta avaliação das capacidades do idoso será fundamental na diminuição do risco de queda inerente ao envelhecimento. Os Smartphones são uma boa ferramenta para a avaliação das capacidades em idosos. Objetivo: Verificar se o smartphone é uma ferramenta de avaliação do ângulo de dorsiflexão ativa da tibiotársica (Dors. TT) e em diferentes parâmetros relacionados com a marcha. ; Métodos: Estudo transversal correlacional, com amostra composta por 27 indivíduos com mais de 60 anos. Procedeu-se à recolha de dados através de um sistema de análise cinemática em 3D com conexão a uma plataforma de forças e de uma aplicação para Smartphone (Fraunhofer®, Porto, Portugal), de forma a verificar a funcionalidade desta última. As variáveis medidas foram a Dors. TT; e todas a variáveis relacionadas com a marcha. Resultados: A dors. TT apresentou uma correlação forte positiva (rs=0,8; p<0,001) entre os dados dos dois instrumentos, assim como no balanço pélvico (rp=0,8; p<0,001), na velocidade na marcha (rp=0,7; p<0,001) e no nº de passos posteriores (rs=0,8; p<0,001). Observou-se uma correlação moderada positiva na duração do passo direito, na duração do passo, na duração da passada, na cadência, no comprimento do passo esq., no comprimento do passo e no deslocamento lateral da pélvis (rp=0,6; p≤0.008). Na percentagem da fase de apoio (%FA) (rs =-0.6; p= 0.007) e na medição da cadência lateral (rs =-0.4; p= 0.042) observou-se uma correlação moderada negativa e na cad. post. (rs=-0,7; p<0,001) uma correlação forte negativa. Conclusão: A aplicação para Smartphone parece ser uma ferramenta útil para avaliar corretamente o ângulo de dorsiflexão da tibiotársica, a contagem do número de passos no sentido posterior, o balanço pélvico e a velocidade. Contudo, necessita ser reajustada para as outras variáveis.

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The objective of this dissertation was to explore the German men’s grooming market and to discuss the usage and purchase behavior of young male adults. After a brief market analysis, this dissertation evaluates the results of qualitative and quantitative research. The conducted research explored the consumer’s reasoning for and attitude towards personal grooming, and their attitude towards product attributes and the aging process. The dissertation concludes that men attach high value to personal grooming but only to the extent that their personal need is satisfied. As the male involvement in MG is highly dependent on each consumer’s individual needs, the market requires a careful segmentation.

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RESUMO: Os mais recentes métodos de neuro imagem tal como a Ressonância Magnética (RM) permitiram obter imagens detalhadas do cérebro humano in vivo. Essas imagens revelam, muitas vezes, achados imprevistos face ao padrão normal, com elevada propensão para os indivíduos idosos e franca coexistência com fatores de risco vascular, como característica dum processo de envelhecimento normal. Embora na última década tenham surgido várias publicações sobre este assunto, ele continua ainda pouco explicado. Um pouco por todo o mundo têm emergido os programas de prevenção da doença e promoção da saúde desenvolvidos pela Saúde Pública suportadas sobretudo pelo avanço das tecnologias médicas que resultaram, entre outros impactos, num crescimento da população idosa. Estima-se, em 2030, uma composição demográfica com 20% de indivíduos acima dos 65 anos. Neste contexto, a doença microvascular cerebral é a causa mais frequente de comprometimento cognitivo vascular no idoso sendo as características senescentes na imagem por RM do tipo lesões isquémicas da Substância Branca (Leukoaraiosis) e enfartes lacunares (Status lacunar), atrofia cerebral, gliose e acumulação excessiva de ferro nos núcleos da base. Esta tese, considerando a linha de investigação de que deriva – Ciências da Vida - especialização em Medicina Clinica - Biotecnologia, reúne e reflete sobre três vertentes ligadas à RM e interdependentes em relação a uma problemática comum. A primeira trata da caracterização da Tecnologia por Ressonância Magnética existente em Portugal, a qual inclui uma avaliação exploratória da aplicação da técnica de Difusão Anisotrópica nos estudos cerebrais. As dimensões analíticas estudadas foram a Tecnológica, Sociodemográfica e Económica. Na recolha de dados recorreu-se a várias fontes de informação e a uma metodologia exploratória faseada, validada pela triangulação dos resultados. A sua análise obedeceu a critérios de estratificação e agrupamento segundo as mesmas dimensões analíticas. Otimização da anisotropia fronto-calosa e [RM 1,5T] no idoso normal e com risco cérebro-vascular A segunda descreve o estudo anátomo – radiológico que recaiu sobre parâmetros de quantificação assente na temática do cérebro do idoso em cadáver segundo uma metodologia experimental aplicada às métricas da difusão por RM. Na terceira, e última, é apresentado o estudo técnico - radiológico para avaliação e otimização da imagem ponderada em difusão em estudos clínicos associados ao cérebro do idoso “The Usual Brain Aging” ou Envelhecimento Cerebral Normal, com base metodológica assente nos critérios e indicadores estabelecidos pelo Estudo de Imagem de Roterdão (Rotterdam Scan Study - RSS). Como principais resultados obteve-se que não existem em Portugal estruturas para avaliação dos equipamentos pesados ou Agência de Avaliação das Tecnologias da Saúde para desenvolver o importante papel da produção de estudos comparativos entre os equipamentos disponíveis no mercado, a relação preço-qualidade e a sua afetação às necessidades clínico-epidemiológicas. Constatou-se que a implementação de equipamentos de RM está fortemente assente em critérios económicos carecendo de recomendações e diretivas para o uso racionalizado destas tecnologias. Quanto a dados quantitativos concluímos que a maioria dos equipamentos está instalada em instituições privadas (80,2%); a intensidade de campo magnético mais frequente é [1,5T] com 119 equipamentos; os equipamentos estão instalados maioritariamente nos distritos de Lisboa (55 unidades) e do Porto (39 unidades); o rácio médio de equipamentos por habitante em Portugal é de 1 para 65 195 habitantes; a amplitude de gradientes com maior expressão na amostra é 30-39mT/m; a maioria dos equipamentos foi instalada no intervalo temporal [2009-2012] com 59 equipamentos; apenas 6 instituições desenvolvem investigação clinica e a maioria das bobinas para estudos de crânio são do tipo Array. O estudo de otimização da técnica da difusão revelou, quanto à avaliação dos valoresb, que os mais baixos (b=500 s/mm2 e b=1000 s/mm2), apresentam maior IS e SNR sendo esta uma boa medida referente à qualidade de imagem, no entanto, os valores-b mais elevados (b=2000 s/mm2) apresentam maior CNR e CR, face aos anteriores, o Otimização da anisotropia fronto-calosa e [RM 1,5T] no idoso normal e com risco cérebro-vascular que apesar de proporcionar inferior detalhe anatómico e consequentemente inferior qualidade de imagem, num encéfalo normal, pode auxiliar na interpretação e apresentar vantagens na identificação de lesões microvasculares sempre que persistirem dúvidas em relação ao diagnóstico diferencial de doença microvascular do tipo status lacunar ou Hiperintensidades da Substância Branca. As alterações deste parâmetro são particularmente refletidas nas diferenças da avaliação da qualidade de imagem na região fronto-calos Concluímos da avaliação quantitativa da concentração média de ferro (26Fe) em todas as faixas etárias que os núcleos da base que apresentam maior concentração são, por ordem decrescente: Substância Nigra, Globus Pallidus, Putamen, Tálamo, Núcleo Rubro e Núcleo Caudado; que existe uma predominância na concentração de ferro (26Fe) no hemisfério esquerdo e que os indivíduos do género masculino apresentam mais ferro (26Fe) que os do género feminino nas faixas etárias [30-40[, [40-50[ e [50-60[. Como principal conclusão do estudo da concentração média de ferro em relação à idade destacamos que a concentração média de ferro (26Fe) é superior nos grupos etários superiores, logo aumenta com a idade, sobretudo na Substância Nigra e no Núcleo Lenticular. No estudo técnico-radiológico encontrámos evidências do aumento da difusibilidade da água na substância branca subcortical dos sujeitos idosos comparativamente aos mais jovens. Uma relação idêntica foi avaliada nos tálamos. O aumento relacionado com a idade parece ser predominantemente observado em doentes com mais de 65 anos de idade o que pode refletir alterações estruturais ligeiras associados ao envelhecimento normal. Os resultados indicam que a análise quantitativa das imagens ponderadas em difusão fornece informações, sobre a estrutura do cérebro, as quai s não estão disponíveis apenas por inspeção visual, tanto nas imagens ponderadas em difusão como em outras sequências de aplicação clínica de rotina. Para fazer face às desvantagens dos sistemas de quantificação das HSB os quais são dispendiosos, complexos, requererem tecnologia e formação específicas, recomendamos que a aplicação automatizada GUIAL, desenvolvida ao longo do nosso trabalho é de utilização elementar e prática para que seja introduzida nos sistemas de aquisição de imagem por RM com o fim de integrar o processamento de imagem nos indivíduos portadores de fatores de risco vascular. A avaliação do ADC, nesta amostra, permitiu concluir que a variação desta variável é explicada estatisticamente pela existência da condição clínica de status lacunar em ambos os hemisférios ou por outras palavras, o status lacunar influencia o valor de ADC. Embora uma pequena percentagem da variação do ADC seja explicada pelo género, o ADC nos homens foi superior ao das mulheres o que não nos surpreende, pois são também os homens onde a frequência de doença microvascular se revelou mais expressiva. Os valores do ADC, globalmente, entre os hemisférios cerebrais não mostraram alterações exceto na SB entre os idosos e não idosos. A SB da região frontal mostrou valores diminuídos na anisotropia e isotropia face às restantes áreas anatómicas. Os estudos indicam que na idade avançada existe uma maior predisposição para suscetibilidades de estrutura com status de desconexão. A classificação das HSB foi superior em indivíduos mais velhos e com status lacunar, e em menor quantidade (inferior rating de classificação) nos indivíduos idosos sem status lacunar. As alterações volumétricas foram mais frequentes no homem do que na mulher, presumivelmente devido à associação com a elevada classificação de status lacunar. Um aumento do índice de Evan correspondeu, neste estudo, ao aumento das HSB, à diminuição do volume cerebral total, à expansão ventrículo-sulcal frontal e ao aumento da medida do ângulo caloso. Estes resultados foram agravados pela classificação elevada de status lacunar nos indivíduos que apresentaram indícios de doença de pequenos vasos, com manifesto aumento dos espaços de Virchow-Robin,enfartes lacunares ou HSB. Esses resultados foram mais expressivos no género masculino do que no feminino revelando uma maior vulnerabilidade sobretudo na atrofia frontal nos homens. Por sua vez as dimensões do Corpo Caloso tornaram-se reduzidas devido à compressão dos ventrículos laterais e terceiro ventrículo. Estes indicadores tiveram expressão particularmente nos indivíduos com mais de 65 anos. ---------------------------------------------------------------------------------------------ABSTRACT: The latest neuroimaging methods, such as Magnetic Resonance Imaging (MRI), have enabled detailed images of in vivo human brain. These images reveal often unexpected findings related to the normal pattern, with high predisposition for the elderly people with forthright coexistence with vascular risk factors such as characteristics of a normal aging process. Although it has been, in the last decade, several publications on this subject, it is still little explained. All over the world have emerged disease prevention programs and health promotion developed by the Public Health sector, supported mainly by the advancement of medical technologies that have resulted, among other impacts, in a growing of the elderly population. It is estimated, in 2030, a demographic composition with 20% o people over 65 years. In this context, microvascular disease is the most common cause of cognitive vascular impairment in the elderly and senescent characteristics in the MRI trough ischemic lesions of the white matter (Leukoaraiosis) and lacunar infarcts (lacunar status), cerebral atrophy, gliosis and iron accumulation in the basal ganglia in excess.This thesis, considering the research line that stems - Life Sciences - specialization in Clinical Medicine, Biotechnology, gathers and reflects on three aspects linked to MR, interdependent and related to a common problem. The first deals with the Magnetic Resonance Technology characterization in Portugal, which includes an exploratory evaluation of the implementation of Anisotropic Diffusion technique in brain studies. The analytical dimensions studied were the Technologic, Socio-demographic and Economics. Collecting data was supported by different sources of information and was applied an exploratory methodology whose results were validated by triangulation. The research method was grouped and stratified criteria under the same analytical dimensions. The second describes the anatomical study - which was focused on radiological measurement parameters, based on the brain’s specimen under an experimental methodology applied to MRI diffusion metrics. Radiological evaluation and optimization of the weighted image diffusion in clinical studies were associated with the brain of the elderly "The Usual Brain Aging" with methodological basis based on established criteria and indicators by Rotterdam Scan Study (RSS). The main results obtained reveal the inexistence frameworks in Portugal for evaluation of equipments or Agency of Health Technology to produce studies comparing the equipment available on the market, the value for money and its allocation to clinical and epidemiological needs. It was found that the implementation of MRI equipment is strongly based on economic criteria lacking recommendations and guidelines for the rationalized use of these technologies. As the quantitative data we conclude that most of the scanners are located in private clinical institutions (80,2%); the most frequent magnetic field intensity is [1.5T] with 119 scanners; the scanners are mainly installed in Lisbon (55 units) and Porto (39 units) districts; the average ratio of equipment per capita in Portugal is 1 to 65 195 people; the gradient power with higher expression in the sample is 30-39mT / m;most of the scanners were installed in the years range [2009-2012 years] with 59 equipment; only 6 clinical placements develop clinical research and the most coils for brain studies are of Array type. The optimization study of diffusion technique revealed, as the assessment of the bvalues, the lower (b = 500 s / mm2 and b = 1000 s / mm 2), promotes an increase in the SI and SNR being this measure related to a higher image quality, however the highest b values (b = 2000 s / mm 2) have a higher CNR (Contrast to Noise-Ratio) and CR (Contrast Ratio), compared to the previous ones. This may provide less anatomical details and, thus, ower image quality, of a normal brain, however can help the interpretation and have advantages in identifying microvascular injuries when doubts persist regarding the differential diagnosis of microvascular disease of lacunar or WMH (White Matter Hyperintensities) status type. Changes on this parameter are Otimização da anisotropia fronto-calosa e [RM 1,5T] no idoso normal e com risco cérebro-vascular particularly reflected in the differences of image quality evaluation in the frontocallosum anatomical area. We conclude from the quantitative assessment of the average concentration of iron (26Fe), in all age groups to the basal ganglia, that the higher concentrations are, in descending order: Nigral Substantia, Globus pallidus, Putamen, Thalamus, Rubio nucleus and Caudate nucleus; that there is a predominance in the concentration of iron (26Fe) in the left hemisphere and that male gender show higher iron (26Fe) level tha females, in the age groups [30-40 [[40-50 [and [50- 60 [. Regarding a main conclusion of the mean concentration study of iron, in terms of age we point out that the average concentration of iron (26Fe) is higher among older groups and increases with age, especially in Nigral Substantia and Lenticular Nucleus. On the technical and radiological study we found evidence of an increased in water /diffusivity in the ubcortical white matter of the elderly compared with younger subjects. A similar relationship was assessed in the Thalamus. The increase agerelated seems to be predominantly observed in patients over 65 years which may reflect minor structural changes associated with normal aging. The results indicate that quantitative analysis of diffusion weighted imaging can provide information about the structure of the brain which is not reached only by visual inspection or standard sequences applied in clinical routine. To address the disadvantages the systems of quantification of WMH which the authors state that are costly, complex, require specific technology and training, we recommend that the automated application GUIAL, developed over our work is basic and practical to use and to be introduced in MR image systems acquisition in order to integrate image processing in patients with vascular risk factors. The evaluation of the ADC showed that its variation is statistically explained by the existence of the medical condition of lacunar status, in both hemispheres, or in other words, the lacunar status influences the ADC value. Although a small percentage of the ADC variation is explained by gender, the ADC in men was higher than women which Otimização da anisotropia fronto-calosa e [RM 1,5T] no idoso normal e com risco cérebro-vascular do not surprise us, since they are also men where the frequency of microvasculardisease has proved more significant. The values of ADC, overall, between the cerebral hemispheres showed no changes but were different in WM among the elderly and non-elderly subjects.The WM's forehead showed decreased values in anisotropy and isotropy face the other anatomical areas. The studies indicate that in old age there is a greater tendency to higher susceptibility to disconnection- status framework. The classification of WMH was higher in elderly people and lacunar status, and fewer (lower classification rating) in the elderly without lacunar status. volumetric changes were more frequent in men than in women, most probably because of its association with high lacunar status rating. An increase of Evan index corresponded, in this study, to an increase in WMH, to a decreased of total brain volume, to a ventricle sulcal frontal and callous angle expansion. These results were wound up by high ranking of lacunar status in subjects who had small vessel disease, clear increase in spaces of Virchow-Robin, lacunar infarctions or WMH. These results were more significant in males than in females revealing vulnerability particularly in the frontal atrophy in men. In turn the size of Corpus Callosum because reduced due to the compression of the lateral and third ventricles. These indicators had expression particularly in individuals over 65 years.

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Whereas the role of the anterior cingulate cortex (ACC) in cognitive control has received considerable attention, much less work has been done on the role of the ACC in autonomic regulation. Its connections through the vagus nerve to the sinoatrial node of the heart are thought to exert modulatory control over cardiovascular arousal. Therefore, ACC is not only responsible for the implementation of cognitive control, but also for the dynamic regulation of cardiovascular activity that characterizes healthy heart rate and adaptive behaviour. However, cognitive control and autonomic regulation are rarely examined together. Moreover, those studies that have examined the role of phasic vagal cardiac control in conjunction with cognitive performance have produced mixed results, finding relations for specific age groups and types of tasks but not consistently. So, while autonomic regulatory control appears to support effective cognitive performance under some conditions, it is not presently clear just what factors contribute to these relations. The goal of the present study was, therefore, to examine the relations between autonomic arousal, neural responsivity, and cognitive performance in the context of a task that required ACC support. Participants completed a primary inhibitory control task with a working memory load embedded. Pre-test cardiovascular measures were obtained, and ontask ERPs associated with response control (N2/P3) and error-related processes (ERN/Pe) were analyzed. Results indicated that response inhibition was unrelated to phasic vagal cardiac control, as indexed by respiratory sinus arrhythmia (RSA). However, higher resting RSA was associated with larger ERN ampUtude for the highest working memory load condition. This finding suggests that those individuals with greater autonomic regulatory control exhibited more robust ACC error-related responses on the most challenging task condition. On the other hand, exploratory analyses with rate pressure product (RPP), a measure of sympathetic arousal, indicated that higher pre-test RPP (i.e., more sympathetic influence) was associated with more errors on "catch" NoGo trials, i.e., NoGo trials that simultaneously followed other NoGo trials, and consequently, reqviired enhanced response control. Higher pre-test RPP was also associated with smaller amplitude ERNs for all three working memory loads and smaller ampUtude P3s for the low and medium working memory load conditions. Thus, higher pretest sympathetic arousal was associated with poorer performance on more demanding "catch" NoGo trials and less robust ACC-related electrocortical responses. The findings firom the present study highlight tiie interdependence of electrocortical and cardiovascular processes. While higher pre-test parasympathetic control seemed to relate to more robust ACC error-related responses, higher pre-test sympathetic arousal resulted in poorer inhibitory control performance and smaller ACC-generated electrocortical responses. Furthermore, these results provide a base from which to explore the relation between ACC and neuro/cardiac responses in older adults who may display greater variance due to the vulnerabihty of these systems to the normal aging process.

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Reduced capacity for executive cognitive function and for the autonomic control of cardiac responsivity are both concomitants of the aging process. These may be linked through their mutual dependence on medial prefrontal function, but the specifics ofthat linkage have not been well explored. Executive functions associated with medial prefrontal cortex involve various aspects ofperformance monitoring, whereas centrally mediated autonomic functions can be observed as heart rate variability (HRV), i.e., variability in the length of intervals between heart beats. The focus for this thesis was to examine the degree to which the capacity for phasic autonomic adjustments to heart rate relates to performance monitoring in younger and older adults, using measures of electrocortical and autonomic activity. Behavioural performance and attention allocation during two age-sensitive tasks could be predicted by various aspects of autonomic control. For young adults, greater influence of the parasympathetic system on HRV was beneficial for learning unfamiliar maze paths; for older adults, greater sympathetic influence was detrimental to these functions. Further, these relationships were primarily evoked when the task required the construction and use of internalized representations of mazes rather than passive responses to feedback. When memory for source was required, older adults made three times as many source errors as young adults. However, greater parasympathetic influence on HRV in the older group was conducive to avoiding source errors and to reduced electrocortical responses to irrelevant information. Higher sympathetic predominance, in contrast, was associated with higher rates of source error and greater electrocortical responses tq non-target information in both groups. These relations were not seen for 11 errors associated with a speeded perceptual task, irrespective of its difficulty level. Overall, autonomic modulation of cardiac activity was associated with higher levels of performance monitoring, but differentially across tasks and age groups. With respect to age, those older adults who had maintained higher levels of autonomic cardiac regulation appeared to have also maintained higher levels of executive control over task performance.

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Questions : Cette thèse visait à répondre à deux questions fondamentales : 1) Est-ce que les athlètes qui présentent un historique de commotions cérébrales du sport en conservent des effets délétères à long terme? ; et 2) Est-ce que les effets néfastes des commotions cérébrales récurrentes sur le fonctionnement tant cognitif que moteur sont cumulatifs? Devis expérimental : À l’aide d’un plan d’investigation double-cohorte réalisé avec un groupe d’athlètes évoluant au niveau universitaire et un autre formé d’anciens athlètes universitaires testés plus de trois décennies plus tard, les quatre études qui composent cette thèse ont employé des méthodes raffinées d’investigation des fonctions cognitives et motrices pour en déceler des atteintes persistantes. Méthodologie : Les potentiels évoqués cognitifs ainsi que les tests neuropsychologiques ont permis de sonder le fonctionnement cognitif de ces athlètes alors que la stimulation magnétique transcrânienne, une plateforme de force permettant de mesurer la stabilité posturale ainsi qu’un système d’enregistrement tridimensionnel des mouvements rapides alternatifs ont servi à l’évaluation de l’intégrité du système moteur. Résultats : Cette thèse a permis de déceler des altérations persistentes et cumulatives des fonctions cognitives et motrices. De plus, ces subtiles atteintes observées chez les jeunes athlètes, affectant essentiellement des marqueurs neurophysiologiques sous-cliniques du fonctionnement cognitif et moteur, s’étaient accentuées chez les anciens athlètes universitaires qui montraient un déclin quantifiable tant des fonctions cognitives que motrices. Discussion : Ces résultats suggèrent d’une part que les commotions cérébrales du sport entraînent des altérations cognitives et motrices chroniques qui s’accentuent en fonction du nombre de commotions cérébrales subies. D’autre part, les effets délétères des commotions cérébrales du sport sur le fonctionnement cognitif et moteur combinés à ceux associés au processus de vieillissement entraînent un déclin cognitif et moteur quantifiable en comparaison aux anciens athlètes n’ayant jamais subi de commotions cérébrales.

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La dynamique démographique ayant cours au sein de la région des Caraïbes est très particulière, notamment par la rapidité avec laquelle la population vieillit, un rythme des plus élevés par rapport aux autres régions du monde. Les enjeux cruciaux que sont ceux d’assurer la qualité de vie des aînés d’aujourd’hui et de demain ainsi qu’une gestion efficace de ces sociétés vieillissantes se doivent d’être abordés et pris en compte. Le présent mémoire diffuse les résultats d'une analyse ciblée des caractéristiques sociodémographiques des personnes âgées de quatre États des Caraïbes (Antigua-et-Barbuda, Sainte-Lucie, Saint-Vincent-et-les-Grenadines et Trinité-et-Tobago) à partir des données de leur plus récent recensement. Ce portrait met une emphase particulière sur les conditions de vie, la santé et la participation sur le marché du travail des personnes âgées, soit sur les grands thèmes des trois objectifs du Plan d’action international sur le vieillissement de Madrid. Par ailleurs, un regard est posé sur les effets des cinq premières années en vigueur du Plan de Madrid sur les populations caribéennes. Les informations obtenues à la suite d’interviews effectués auprès de personnes contacts de quelques pays caribéens sont synthétisées et identifient les efforts déployés principalement par les gouvernements pour inclure les objectifs du Plan de Madrid et autres enjeux du vieillissement démographique dans les mécanismes et les politiques de développement social et économique ainsi que ceux de respect des droits humains.

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Outre ses effets sur le système visuel classique permettant la formation des images, la lumière agit sur plusieurs fonctions « non-visuelles ». Celles-ci incluent la constriction pupillaire, la température corporelle, la sécrétion hormonale, le cycle veille-sommeil, la vigilance et les performances cognitives. Les fonctions non-visuelles sont préférentiellement sensibles aux lumières à longueurs d’ondes courtes (lumière bleue) en comparaison aux longueurs d’ondes plus longues (lumière verte). Il est proposé que le vieillissement s’accompagne d’une diminution de la sensibilité des fonctions non-visuelles à la lumière. Cette recherche vise à évaluer les effets de l’âge sur la constriction pupillaire et la sensibilité cérébrale à la lumière lors de l’exécution de tâche cognitive. Deux groupes de sujets, 16 jeunes (18-30 ans) et 14 âgés (55-70 ans), ont suivis un protocole de pupillométrie visant à mesurer la dynamique pupillaire lors d’exposition à des lumières bleues et vertes monochromatiques de trois intensités différentes. Les résultats ont montré davantage de constriction en bleu qu’en vert et des effets plus importants suivant l’augmentation de l’intensité lumineuse. Nos résultats ne montrent cependant pas de différence d’âge sur la constriction pupillaire à la lumière suggérant la préservation de cette réponse non-visuelle. Dans un deuxième temps, les mêmes sujets ont exécuté une tâche cognitive en imagerie par résonance magnétique fonctionnelle (IRMf) tandis qu’ils étaient maintenus dans la noirceur, ou exposés à des lumières bleues. Les résultats ont montré une diminution des effets de la lumière avec l’âge dans le thalamus, l’amygdale, l’insula et l’aire ventrale tegmentale, régions engagées dans la vigilance, l’attention et les processus émotionnels. Les modifications qui s’opèrent sur les différentes fonctions non-visuelles avec l’âge ne semblent pas homogènes. Ces résultats corroborent les évidences animales qui montrent différents seuils de sensibilités à la lumière et la présence de réseaux neuronaux partiellement indépendants pour les diverses réponses non-visuelles. De plus, ils sont les premiers à démontrer que les effets neuronaux stimulants de la lumière bleue sur la cognition sont diminués avec l’âge. Les recherches devront évaluer si cette diminution de sensibilité influence les performances cognitives au cours du vieillissement. Enfin, un raffinement de nos connaissances permettra de mieux adapter l’environnement lumineux avec l’âge.

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Avec l’avancement en âge, les personnes âgées qui vivent à domicile ont besoin du soutien des membres de leur entourage, notamment d’un aidant familial dont le rôle n’est toutefois pas sans conséquence sur sa santé. Les écrits empiriques ont montré que certains aidants sont résilients, c’est-à-dire qu’ils s’adaptent à leur situation et continuent leur développement. Toutefois, aucune étude n’a été effectuée au Liban auprès des aidantes familiales pour expliquer la résilience dans ce contexte et, plus spécifiquement, pour déterminer les facteurs qui pourraient l’influencer. Cette étude à devis corrélationnel de prédiction avait pour but de vérifier certaines des relations postulées par un modèle empirique découlant des écrits, soit la contribution de facteurs personnels (stratégies de coping et auto-efficacité) et de facteurs contextuels (relations familiales, perception du soutien de l’entourage, et sens accordé au « prendre soin »),à la résilience des aidantes familiales libanaises qui prennent soin d’un proche âgé à domicile. L’étude a été effectuée au Liban auprès d’un échantillon de convenance composé de 140 aidantes familiales principales cohabitant à domicile avec un parent âgé de 65 ans et plus ayant une perte d’autonomie fonctionnelle ou cognitive. La collecte des données a été réalisée en arabe en utilisant un guide d’entrevue standardisé regroupant des instruments nord-américains traduits selon la méthode de traduction inversée parallèle, de même qu’une question ouverte portant sur la perception des aidantes de la résilience, soit des facteurs qui les aident à continuer à prendre soin de leur proche âgé tout en continuant à se développer. Une analyse de régression hiérarchique a permis de vérifier la contribution unique des facteurs personnels et contextuels à expliquer la résilience des aidantes familiales, en contrôlant pour l’âge et le niveau de scolarité des aidantes et pour le niveau de perte d’autonomie et la fréquence des comportements dysfonctionnels de leurs parents âgés. Une analyse de contenu a permis de décrire la perception des aidantes eu égard à la résilience. Les résultats ont montré que le modèle empirique, incluant les variables de contrôle explique 54% de la variance de la résilience et que quatre des facteurs considérés, soit les stratégies de coping centrées sur le problème, les stratégies de coping centrées sur les émotions, le sentiment d’auto-efficacité et le sens du « prendre soin » ont une contribution statistiquement significative à la résilience des aidantes. Parmi ces quatre facteurs, le sens du « prendre soin » et le sentiment d’auto-efficacité expliquent davantage de variance, soit 11% et 5% respectivement. L’analyse qualitative du discours des aidantes a montré qu’elles prennent soin de leur proche âgé surtout par souci de réciprocité, mais également parce qu’il s’agit d’un membre de la famille et par respect pour Dieu. Ce sont par ailleurs leurs croyances et la satisfaction liée au prendre soin qui les aident à continuer et à se développer. Cette étude offre une meilleure compréhension du concept de la résilience des aidantes familiales au Liban et de certains facteurs qui en sont des prédicteurs significatifs. Elle offre des pistes pour l’intervention infirmière dans le but de promouvoir la santé de la personne/famille en tant que partenaire de soins. Des recommandations pour la pratique, la formation et la recherche sont proposées.