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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Qualidade fisiológica e sensorial de sementes de café (Coffea arabica L.) produzidas em diferentes altitudes e faces de exposição da montanha / Physiological and sensorial quality of coffee seeds (Coffea arabica L.) produced at different altitudes and faces of mountain exposure

Hormaza Martínez, Paola Andrea 16 February 2017 (has links)
Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2017-09-06T11:29:13Z No. of bitstreams: 1 texto completo.pdf: 2670142 bytes, checksum: bacbe4a6f58c3e715c44cb86aea5eb25 (MD5) / Made available in DSpace on 2017-09-06T11:29:13Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2670142 bytes, checksum: bacbe4a6f58c3e715c44cb86aea5eb25 (MD5) Previous issue date: 2017-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O café é um dos produtos agrícolas mais valiosos exportados em todo o mundo. Em consequência disso, vê-se a necessidade de compreender a influência do meio ambiente (altitude, insolação, temperatura, etc) na qualidade fisiológica da semente e sensorial da bebida, para atender às demandas crescentes dos consumidores do grão e sementes nas diferentes áreas (consumo e insumo agrícola). Para isso, determinou-se as relações entre a atividade do sistema antioxidante e o acúmulo de reservas nas sementes e grãos de café produzidos em condições ambientais contrastantes e seus efeitos na qualidade. Componentes de qualidade fisiológica da semente como porcentagem de germinação total e testes de vigor (primeira contagem da germinação, comprimento total, da raiz principal e dos diferentes diâmetros de raiz, massa seca de raiz, da parte aérea e total, condutividade elétrica e lixiviação de potássio) foram determinados. Atividade do sistema antioxidante, da polifenoloxidase, MDA, teor de sacarose, açucares redutores, solúveis e totais, amido, proteínas e lipídeos e observação anatômica da semente de café foram realizadas. Além disso a qualidade sensorial em cada uma das faces e altitude também foi determinado. A análise centrou-se em determinar o efeito sobre o metabolismo da semente café causado pelo efeito da altitude e a face de insolação ao longo do desenvolvimento e germinação das sementes. Em todos os ensaios com embriões de café, foi detectada a atividade das enzimas do sistema antioxidante. Encontrou-se as maiores atividades das enzimas CAT e SOD nas sementes produzidas nas faces e altitudes de menor qualidade fisiológica (NF>900 e SQ<750). Nos grãos com menor qualidade sensorial encontrou-se maior atividade da PPO (NF<750). Do mesmo modo foram encontradas diferenças no teor das reservas na semente. Houve maior acumulo de proteínas nas altitudes acima de 900 m independentemente da face, o que sugere que o acumulo desta reserva pode ser influenciado pela altitude. A face e altitude de menor qualidade de sementes (SQ<750), apresentam os menores teores de açucares redutores, proteínas e lipídeos. As análises bioquímicas e anatômicas foram a ferramentas eficazes na avaliação e compreensão de alguns dos efeitos da insolação e a altitude na produção de sementes de café com boa qualidade. No entanto, os efeitos do ambiente e altitude nos parâmetros de qualidade avaliados ainda não são completamente compreendidos e há espaço para mais estudos para tentar explicar as contribuições na qualidade (sensorial e fisiológica), que possam aportar as diferentes condições ambientais (altitude e insolação) no melhoramento da qualidade. / Coffee is one of the most valuable agricultural products exported around the world. Consequently, it is necessary to understand the influence of the environment (altitude, insolation, temperature, etc.) on the seed physiological quality and sensorial quality of the drink, in order to meet the growing demands of grain and seed consumers in different areas (consumption and agricultural input). For this, we determined the relations between the activity of the antioxidant system and the accumulation of reserves in the seeds and coffee beans produced in contrasting environmental conditions and their effects on the quality. Physiological seed quality components, such as the percentage of total germination and vigor tests (first germination count, total length, root and root diameters, root, shoot and total dry matter, electrical conductivity and Potassium leaching) were determined. The activity of the antioxidant system, polyphenoloxidase, MDA, sucrose content, reducing, soluble and total sugars, starch, proteins and lipids and anatomical observations of the coffee seed were carried out. In addition, the sensory quality on each face and altitude was determined. The analysis focused on determining the effect on the metabolism of the coffee seed caused by the effect of altitude and the face of insolation along the development and germination of the seeds. In all assays with coffee embryos, the activity of the enzymes of the antioxidant system was detected. The highest activity of the CAT and SOD enzymes in the seeds produced in the faces and altitudes of lower physiological quality (NF> 900 and SQ <750) was found, and in the grains with lower sensory quality, greater PPO activity was found (NF <750). Likewise, differences in the content of the analyzed seed contents were found. There was a higher accumulation of proteins at altitudes above 900 m regardless of the Face, which suggests that the accumulation of this reserve can be influenced by altitude. The face and altitude of lower seed quality (SQ <750), present the lower contents of reducing sugars, proteins and lipids. Biochemical and anatomic analyzes were effective tools to evaluate and understand some of the effects of insolation and altitude on the production of good quality coffee seeds. However, the effects of the environment and altitude on the quality parameters evaluated are not yet fully understood. There is room for further studies to try to explain the contributions in the quality (sensorial and physiological) that can contribute to different environmental conditions (altitude and insolation) in quality improvement.
32

O mar e a cidade mudanças climáticas e o desenvolvimento urbano em Joinville (SC) /

Braun, Samara, 1991-, Aumond, Juarês José, 1946-, Universidade Regional de Blumenau. Programa de Pós-Graduação em Desenvolvimento Regional. January 2017 (has links) (PDF)
Orientador: Juarês José Aumond. / Dissertação (Mestrado em Desenvolvimento Regional) - Programa de Pós-Graduação em Desenvolvimento Regional, Centro de Ciências Humanas e da Comunicação, Universidade Regional de Blumenau, Blumenau.
33

Using helicopter noise to prevent brownout crashes: an acoustic altimeter

Freedman, Joseph Saul 08 July 2010 (has links)
This thesis explores one possible method of preventing helicopter crashes caused by brownout using the noise generated by the helicopter rotor as an altimeter. The hypothesis under consideration is that the helicopter's height, velocity, and obstacle locations with respect to the helicopter, can be determined by comparing incident and reflected rotor noise signals, provided adequate bandwidth and signal to noise ratio. Heights can be determined by measuring the cepstrum of the reflected helicopter noise. The velocity can be determined by measuring small amounts of Doppler distortion using the Mellin-Scale Transform. Height and velocity detection algorithms are developed, optimized for this application, and tested using a microphone array. The algorithms and array are tested using a hemianechoic chamber and outside in Georgia Tech's Burger Bowl. Height and obstacle detection are determined to be feasible with the existing array. Velocity detection and surface mapping are not successfully accomplished.
34

Ictiofauna de duas microbacias - ribeirão dos Buenos e rio Guaratinguetá - na serra da Mantiqueira oriental

Rondineli, Giulianna Rodrigues [UNESP] 19 April 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-19Bitstream added on 2014-06-13T20:07:23Z : No. of bitstreams: 1 rondineli_gr_dr_rcla.pdf: 2227830 bytes, checksum: 5627c287ce51efee9419433f5e5ef4bb (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As microbacias do ribeirão dos Buenos e do rio Guaratinguetá, integrantes da bacia do rio Paraíba do Sul, são sistemas hidrográficos que descem das encostas da serra da Mantiqueira oriental, sendo isoladas de outros sistemas contíguos por formações de relevo. O objetivo deste trabalho foi definir como as comunidades de peixes das microbacias do ribeirão dos Buenos e do rio Guaratinguetá estão estruturadas e como variam suas composições no espaço e no tempo. Estudos sobre a biologia dessas populações foram conduzidos de modo a entender como ocorrem os processos de substituição de espécies. Para contemplar regiões da encosta, do pediplano e do vale foram demarcados 15 pontos de coleta, 8 deles na microbacia do ribeirão dos Buenos e 7 na do rio Guaratinguetá. As coletas aconteceram ao longo de um ano, sendo o aparelho de pesca elétrica, a redinha-de-arrasto e as redes-deespera os apetrechos de pesca utilizados. Variáveis estruturais dos riachos e físicas e químicas da água também foram coletadas. Foram capturados 2805 indivíduos, distribuídos em 34 espécies, 13 famílias e 7 ordens. Na microbacia do ribeirão dos Buenos, ocorreram 27 espécies, das quais 4 foram exclusivas de seus riachos e na microbacia do rio Guaratinguetá 30 espécies foram amostradas, sendo 8 delas também exclusivas de seus riachos. Um gradiente crescente da diversidade, riqueza e equitabilidade foi observado da encosta em direção ao vale. Interações significativas entre ambientes e microbacias para os índices de diversidade e riqueza indicaram que pelo menos um ambiente em uma microbacia diferiu quanto à diversidade e riqueza de espécies. Na dimensão temporal, nenhuma variação significativa nos índices de diversidade, riqueza e equitabilidade foi detectada. Um padrão de adição de espécies, indo da encosta em direção ao pediplano, pode ser observado nas microbacias estudadas... / The watersheds of Buenos and Guaratinguetá streams, integrants of the Paraíba do Sul river basin are systems that comes down the slopes of the serra da Mantiqueira eastern, being isolated from other systems by contiguous relief formations. The aim of this work was to determine how fish communities of the Buenos and Guaratinguetá watersheds are structured and how their composition varies in space and time. Studies on the biology of these populations were conducted in order to understand the processes as species replacement in time and space. In order to include regions of the slope, piedmont and the valley were marked 15 collection points, 8 of them in the Buenos watershed and 7 in the Guaratinguetá watershed. Sampling took place over a year, and the following fishery equipment was used: electric fishing equipment, gill nets and a sieve. Structural variables of streams and physical and chemical properties of water were also collected. We captured 2805 individuals belonging to 34 species, 13 families and 7 orders. In the Buenos watershed, there were 27 species and the Guaratinguetá watershed were captured 30 species. Four species were unique to streams of the Buenos watershed and 8 to streams of the Guaratinguetá watershed. An increasing gradient of diversity, richness and evenness was observed on the slope toward the valley. Significant interactions between environments and watersheds for the contents of richness and diversity indicated that at least one environment in a watershed differed as to the diversity and species richness. In the temporal dimension, no significant variation in diversity, richness and evenness was detected. A standard of species' addition, ranging from the hillside towards the piedmont can be observed in the watersheds studied, whereas from the piedmont to the valley, we noticed a pattern of species replacement. Among the structural variables and physical... (Complete abstract click electronic access below)
35

Perdas de nitrogênio pela emissão de óxido nitroso (N2O) e sua relação com a decomposição da serapilheira e biomassa de raízes na floresta de Mata Atlântica / Nitrogen losses by emissions of nitrous oxide (N2O) and its relation with litterfall and fine root dynamics in the Atlantic Forest, Brazil

Eráclito Rodrigues de Sousa Neto 12 September 2008 (has links)
Solos de ecossistemas tropicais são considerados maiores emissores naturais de óxido nitroso (N2O) para a atmosfera. Grande parte do N2O produzido a partir destes solos é originada por dois processos microbiológicos, desnitrificação e nitrificação. A dinâmica de produção e decomposição de raízes e de serapilheira também contribuem para os estoques de carbono e nitrogênio no solo e para a produção de N2O e outros gases de efeito estufa. Diante do exposto e da grande importância, produtividade e extensão da Mata Atlântica, o presente estudo apresenta como objetivo principal investigar se as perdas de nitrogênio (N) pela emissão de N2O é um componente importante no ciclo do N na Mata Atlântica e se há uma variação nesses fluxos em relação às diferentes altitudes (100, 400 e 1000 m) e em relação a outros parâmetros (sazonalidade, temperatura, umidade do solo, dinâmica de produção e decomposição de serapilheira e raízes, e razão C:N da serapilheira). Não houve diferença na quantidade de chuva entre as áreas estudadas. A temperatura diminuiu com a altitude e foi significativamente mais baixa na altitude 1000 m. A umidade do solo determinada através dos espaços porosos do solo preenchidos por água diminuiu com a altitude. As áreas localizadas a 100 m apresentaram maior produção de serapilheira e entre as demais altitudes não houve diferença significativa na produção. Ao contrário da produção, o estoque de serapilheira e o tempo para decomposição também aumentou com as altitudes. O solo das parcelas localizados a 1000 m apresentaram biomassa de raízes vivas e mortas significativamente maior (P<0,05) e a razão C:N das raízes foi similar para todas as áreas. Os fluxos médios anuais encontrados para cada altitude durante o ano desta pesquisa foram: 3,2 kg-N ha-1 ano-1, 1,3 kg-N ha-1 ano-1 e 0,6 kg-N ha-1 ano-1 para as altitudes 100, 400 e 1000m, respectivamente. As emissões de N2O foram fortemente influenciadas pela umidade do solo e pela temperatura e diminuíram significativamente com a altitude. Os baixos fluxos de N2O a 1000 m são decorrentes da baixa disponibilidade de NO3- que viabiliza os processo de geração de N2O, que é produzido por desnitrificação.Com base nestes resultados, a Floresta de Mata Atlântica apresenta um ciclo de N mais conservador em relação às florestas da região Amazônica tanto pelas diferenças físico-químicas do solo como temperatura e regimes pluviométricos / Soils of tropical ecosystems are considered one of the major natural sources of nitrous oxide (N2O) to the atmosphere. Most of the N2O in soils is produced by two microbial processes, denitrification and nitrification. Litterfall and fine root dynamics are believed to contribute to the labile carbon (C) and nitrogen (N) and also contribute to the production greenhouse gases. According to these assumptions and regarding to the magnitude of the Brazilian Atlantic Forest this study aimed to investigate the losses of N by the emission of N2O along an altitudinal gradient and the relation between these fluxes and other climatic and edaphic parameters (precipitation, temperature, soil moisture, litterfall and fine roots dynamics). There was no difference in precipitation among the studied areas. Temperature and soil moisture decreased with altitude. Lower altitudes showed high litter production and low stock of soil litter. Root mass was significantly higher at altitude 1000m but root C:N ratio showed no difference among the altitudes. N2O annual soil fluxes were 3,2 kg-N ha-1yr-1, 1,3 kg-N ha-1yr-1, and 0,6 kg-N ha-1yr-1 at 100, 400 and 1000m, respectively. N2O fluxes were significantly influenced by soil moisture and temperature and decreased with altitude. Lower fluxes at 1000m are due to low NO3- availability and thus low N2O production. According to these results, The Atlantic Forest is considered to have a more conservative N cycle related to the Amazon forests due to the differences of soil chemical and physical properties and pluviometric conditions
36

Modèle de géoide marin dans la mer Égée par altimétrie satellitaire

Sammari, Hédia January 2009 (has links)
Depuis les années 1990, l' altimétrie par satellites est entrée dans une phase opérationnelle, grâce à la couverture exceptionnelle procurée par la combinaison de plusieurs missions (TOPEX/POSEIDON, ERS-1/2, Jason-l , ENVISAT, GFO). Ces missions contribuent entre autres à l'étude des marées, de la circulation océanique et du climat global. Ainsi, l'altimétrie spatiale, au moyen d'un radar embarqué sur un satellite, permet de cartographier directement les hauteurs de la surface de la mer d'une manière continue et d'étudier la surface océanique moyenne et aussi le géoïde. Il s'agit dans cette étude de calculer un géoïde local en mer Égée en Méditerranée par l'analyse des mesures altimétriques du satellite Jason-l et du positionnement précis de marégraphes au sol. Une correction d'orbite des données altimétriques et une interpolation sur une grille régulière sont appliquées. La méthode d'interpolation spatiale du krigeage est utilisée pour le calcul du modèle du géoïde sur une grille régulière de la zone d 'étude. La validation externe du modèle s'appuie sur la comparaison avec des données in situ de marégraphe et des modèles existants tels que l'EGM 96.
37

GIS Modeling of Wetlands Elevation Change in Response to Projected Sea Level Rise, Trinity Bay, Texas

Lee, Erica Anne 12 1900 (has links)
This study is a test of a methodology to predict changes in elevation and shoreline position of coastal wetlands in Trinity Bay, Texas, in response to projected sea level rise. The study combines numerical modeling and a geographic information system. A smoothing technique is used on a United States Geographical Survey (USGS) digital elevation model to obtain elevation profiles that more accurately represent the gently sloping wetlands surface. The numerical model estimates the expected elevation change by raster cell based on input parameters of predicted sea level rise, mineral and organic sedimentation rates, and sediment autocompaction rates. A GIS is used to display predicted elevation changes and changes in shoreline position as a result of four projected sea level rise scenarios over the next 100 years. Results demonstrate that this numerical model and methodology are promising as a technique of modeling predicted elevation change and shoreline migration in wetlands. The approach has potential utility in coastal management applications.
38

Conditions for Passenger Aircraft Minimum Fuel Consumption, Direct Operating Costs and Environmental Impact

Caers, Brecht January 2019 (has links) (PDF)
Purpose - Find optimal flight and design parameters for three objectives: minimum fuel consumption, Direct Operating Costs (DOC), and environmental impact of a passenger jet aircraft. --- Approach - Combining multiple models (this includes aerodynamics, specific fuel consumption, DOC, and equivalent CO2 mass) into one generic model. In this combined model, each objective's importance is determined by a weighting factor. Additionally, the possibility of further optimizing this model by altering an aircraft's wing loading is analyzed. --- Research limitations - Most models use estimating equations based on first principles and statistical data. --- Practical implications - The optimal cruise altitude and speed for a specific objective can be approximated for any passenger jet aircraft. --- Social implications - By using a simple approach, the discussion of optimizing aircraft opens up to a level where everyone can participate. --- Value - To find a general answer on how to optimize aviation, operational and design-wise, by using a simple approach.
39

Überprüfung einer einfachen Kopfrechenmethode zur Umrechnung der Fluggeschwindigkeit von CAS in TAS

Lucht, Dennis January 2019 (has links) (PDF)
Zweck - Von Piloten werden u.a. die sogenannten "Manual Flying Skills" gefordert. Dabei muss der Pilot in der Lage sein (ohne Autopiloten) nach grundlegenden Instrumenten zu fliegen. Dafür sind neben Geschick auch Faustformeln erforderlich. Die Faustformeln müssen dafür verlässlich sein. Der Inhalt dieser Arbeit beschäftigt sich exemplarisch mit einer Faustformel zur Umrechnung der kalibrierten Fluggeschwindigkeit (Calibrated Airspeed, CAS) in die wahre Fluggeschwindigkeit (True Airspeed, TAS). --- Methodik - In Excel und Matlab werden die Ergebnisse aus den Berechnungen der Faustformel mit dem Ergebnis einer exakten Berechnungsweise anhand flugmechanischer Formeln verglichen. Dabei wird die Flughöhe und Fluggeschwindigkeit variiert. Es werden die Abweichungen ermittelt und in Diagrammen zwei- und dreidimensional visualisiert. --- Ergebnisse - Die zu prüfende Faustformel liefert in dem für Sie vorgesehen Anwendungsbereich hinreichend genaue Ergebnisse mit Abweichungen unter 5 %. Dabei nehmen die Abweichung zu, umso weiter die Parameter (Höhe und Geschwindigkeit) von typischen Reiseflugbedingungen entfernt sind. --- Bedeutung in der Praxis - Piloten können bedenkenlos auf die in dieser Arbeit geprüfte Faustformel zurückgreifen und kommen so mit überschaubarem Kopfrechenaufwand auf relativ genaue Ergebnisse. --- Wert - Diese Arbeit zeigt, wie mit mäßigem Zeitaufwand in Excel eine Faustformel über einen gesamten Bereich geprüft werden kann. Das Vorgehen kann auf weitere Faustformeln übertragen werden, sodass sich ein Pilot sein "Kniebrett" mit verifizierten Faustformeln füllen kann.
40

Echocardiography for the noninvasive study of the pulmonary circulation: applications to the study of right ventricular effects of targeted therapies of pulmonary hypertension, limiting factors to exercise capacity, and detection of early pulmonary vascular disease in healthy subjects / Apport de l'échocardiographie dans l'étude non invasive de la circulation pulmonaire: (1) étude pharmacologique, (2) étude des facteurs limitant l'aptitude aérobie, (3) étude sur l'identification de l'hypertension artérielle pulmonaire latente

Pavelescu, Adriana 08 October 2012 (has links)
Ce travail a été consacré à l’étude non invasive de la circulation pulmonaire normale par mise en œuvre de l’échocardiographie Doppler. <p>En intégrant les mesures obtenues dans une approche physiopathologique, et en exploitant les nouvelles possibilités d’échocardiographes portables, techniquement performants, nous avons analysé les effets d’un inhibiteur de la phosphodiestérase-5 et d’une prostacycline, pour tenter d’en identifier d’éventuels effets introtropes intrinsèques, nous avons exploré le concept de réserve vasculaire pulmonaire comme facteur limitant de l’aptitude aérobie et indice potentiel d’une atteinte vasculaire pulmonaire précoce, et obtenu des résultats préliminaires permettant d’identifier une hypertension artérielle pulmonaire (HTAP) latente. Nos principaux résultats peuvent être résumés comme suit :<p>1. Chez le sujet sain, en normoxie ou dans un modèle expérimental d’HTAP induite par l’inhalation d’un mélange gazeux hypoxique, le sildenafil per os ou l’epoprostenol par voie intraveineuse, à des doses utilisées en clinique pour le traitement de l’HTAP, améliorent les indices de la fonction ventriculaire droite en proportion de leurs effets vasodilatatoires pulmonaires, sans effets inotropes intrinsèques détectables.<p>2. La consommation d’oxygène maximale du sujet sain augmente en raison directe de son volume capillaire pulmonaire (calculé à partir de sa capacité de diffusion pour l’oxyde nitrique et le monoxyde de carbone) et en raison inverse de sa résistance vasculaire pulmonaire, non seulement en altitude, mais aussi au niveau de la mer. Ce résultat suggère qu’une plus grande réserve vasculaire pulmonaire est propice aux efforts aérobiques intenses, probablement par moindre postcharge ventriculaire droite.<p>3. Des mesures réalisées chez un petit nombre de sujets suggèrent que la distensibilité vasculaire pulmonaire, calculée à partir d’une relation débit-pression vasculaire pulmonaire, est typiquement réduite chez des porteurs asymptomatiques de la mutation BMPR2, qui est actuellement le facteur de risque le plus élevé connu de l’HTAP. La mutation BMPR2 pourrait aussi être associée à une réactivité vasculaire pulmonaire accrue à l’hypoxie. <p>Nos résultats suggèrent indirectement que l’échocardiographie Doppler, de repos ou de stress, pourrait être davantage développée dans la mise au point de patients à risque d’HTAP./<p><p>Novel advances in echocardiography offer the opportunity to reliably characterize pulmonary circulation in terms of pressure-flow relationship, and to better understand the coupling of right ventricular (RV) function with normal and abnormal pulmonary hemodynamics. Moreover, when combined with the measurement of pulmonary capillary blood volume, this renewed methodological approach may help to understand the concept of pulmonary vascular reserve as a limiting factor of exercise capacity and potential sensitive marker of early vascular disease.<p><p>In the present work we used a model of hypoxic pulmonary vasoconstriction to analyse the effects of two targeted therapies of pulmonary arterial hypertension (PAH) on the RV function. We showed that the beneficial effects of these drugs are mainly driven by a decrease in RV afterload and not an enhanced myocardial inotropic state. Whether this is transposable to abnormal RV-arterial coupling in PAH patients remains to be investigated.<p><p>Echocardiography may be useful to explore the pulmonary vascular reserve as an important limiting factor of exercise capacity. We showed that a higher pulmonary vascular reserve, defined by a decreased PVR and increased lung diffusing capacity, allows for an improved aerobic exercise capacity (as assessed by a higher peak oxygen consumption), at a lower ventilatory cost, at sea level and at high altitude. <p><p>Stress echocardiography may detect an abnormal pulmonary vasoreactivity. We showed that asymptomatic relatives of patients suffering from idiopathic pulmonary arterial hypertension, and who carry a bone morphogenetic protein receptor type 2 mutation (BMPR2) present with a decreased pulmonary vascular distensibility and an enhanced pulmonary vasoreactivity to hypoxia, which are identifiable by echocardiography examination. However, the predictive value of these findings is not known. <p><p>Thus echocardiography may represent, in experienced and dedicated hands, a noninvasive, safe, widely available, applicable at the bed-side as well as in extreme environment (e.g. high altitudes), less expensive alternative for the evaluation of the pulmonary circulation, either by the interrogation of pressure-flow relationship (stress echocardiography), by the investigation of the right ventricle global and regional function in relation to its afterload (standard and Tissue Doppler Imaging), or by a combined approach with the measurement of lung diffusing capacity (DLNO / DLCO) to assess the pulmonary vascular reserve.<p><p>The present data are encouraging for further development and implementation of echocardiography for the detection, but also the diagnosis and follow-up of patients with pulmonary hypertension.<p><p> / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished

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