C'est dans son "Orphée Studio", sous-titré "Poésie d'aujourd'hui à voix haute", qu'André Velter parle vraiment d'oralité nouvelle. Déclaration fondée sur l'expérience, ce manifeste de quelques feuillets, rédigés en guise de présentation, est remarquable : simple, enthousiaste et parlant. Tellement prodigue qu'il fut le détonateur de cette thèse. Quatre mille deux cents signes en effet ont suffi à me décider : la nouvelle oralité poétique serait mon sujet. Le terme même d'oralité, trop souvent uniquement appliqué aux griots africains ou aux traditions orales, offre un vaste champ de réalités dès lors qu'il est entendu, non dans son acception moderne, mais bien dans son rapport à la modernité. / It is in his "Orphée Studio", subtitled "Poésie d'aujourd'hui à voix haute", that André Velter really speaks about new poetic orality. Declaration based on the experiment, this proclamation of some layers, written as a presentation, is rare : simple, enthusiastic and speaking. So much prodigal to be it the detonator of this thesis. Four thousand two hundred signs indeed were enough to induce me : new poetic orality would be my subject. The term even of orality, too often only applied to the African griots or the oral traditions, offers a vast field of realities since it is heard, not in its modern meaning, but well in his report with modernity.

Peatlands are a globally important, terrestrial store of carbon and the UK is recognised as an internationally significant holder of peatlands. Of all the kinds of peatland found in the UK, blanket bogs are dominant, representing 87% of the UK’s peatland area. The UK’s peatlands, in contrast to many other areas of boreal/temperate peat, are relatively accessible and as such have been subject to land-management pressures for many thousands of years. These management pressures have led to the deterioration of many peatlands in the UK, with only 1% of England’s peatlands being considered ‘pristine’ in a Natural England report (Natural England, 2010). Climate change and increasing land-use pressures are predicted to affect all UK peatlands in coming years. As such, studies of the drivers of carbon cycling on UK peatlands are being undertaken in order to help in the construction of models to predict the dynamics of peatland carbon balance. These models will subsequently enable land-managers and policy makers to take informed decisions regarding peatland management and carbon storage. One such model of peatland carbon balance is the Durham Carbon Model, which uses a mass balance between fluxes of carbon in and out of a peatland in order to estimate its net carbon budget. While the Durham Carbon Model is able to deal with the effects of some aspects of land-management on peatland carbon balance, there remain a number of important drivers as yet unaccounted for in the model. As such, the remit of this thesis was to conduct in-situ, experiments in order to provide additional data on peatland carbon cycling with a view to incorporating these drivers into the model. Specifically, this research examines three areas as yet unaccounted for in the Durham Carbon Model: altitude, vegetation and diurnal processes. These factors are considered relative to CO2 flux and, in some cases, soil pore water dissolved organic carbon concentration. Additional experiments were also performed to determine whether empirical models of CO2 flux can be physically interpretable. Results obtained for this thesis suggest that the most important factor in predicting CO2 flux on blanket peat soils is vegetation type and vegetation mediated processes, i.e. photosynthetic controls on respiration. Moreover, the relationship between respiration and photosynthesis was found across a range of other factors and temporal scales. In addition to vegetation, altitude was found to significantly affect CO2 for some vegetation types. Therefore, both of these factors are to be incorporated into the Durham Carbon Model. Experiments suggested that empirical models of CO2 flux can be physically interpretable. The results of the diurnal experiment gave evidence to support the hypothesis that some component of the relationship between photosynthesis and respiration is temporally lagged, perhaps by 3 hours. However, the results were not unequivocal and thus further work is needed to fully examine some of the results presented herein.

Submitted to the Information Technology (IT) Department in conformity with the requirements for the degree of Doctor of Philosophy in Information Technology, Durban University of Technology. Durban, South Africa, 2016. / This doctoral research introduces an integration of satellite systems and new stratospheric platforms for weather observation, imaging and transfer of meteorological data to the ground infrastructures. Terrestrial configuration and satellite communication subsystems represent well-established technologies that have been involved in global satellite sensing and weather observation area for years. However, in recent times, a new alternative has emerged based on quasi-stationary aerial platforms located in the Stratosphere called High Altitude Platform (HAP) or Stratospheric Communication Platforms (SCP). The SCP systems seem to represent a dream come true for communication engineers since they preserve most of the advantages of both terrestrial and satellite communication systems. Today, SCP systems are able to help, in a more cost effective way, developments of space Earth sensing and weather observation and weather sensing and observation. This new system can provide a number of forms ranging from a low altitude tethered balloon to a high altitude (18 – 25 km) fuel-powered piloted aircraft, solar-powered unmanned airplanes and solar-powered airship.

Introducción. El vivir en grandes alturas genera que los pobladores se adapten biológica y socialmente al ambiente. El objetivo fue determinar la diferencia del rendimiento físico (RF) en poblaciones rurales a nivel del mar y a gran altitud. Material y métodos. Estudio transversal en comunidades rurales de Áncash, Perú, ubicadas a 3345 m s.n.m. y 6 m s.n.m. Se midió RF según el Short Physical Performance Battery (SPPB) y otros factores asociados. Se calculó las razones de prevalencia ajustadas (RPa). Resultados. Se evaluó a 130 adultos mayores en la comunidad de gran altitud y 129 en la costa, la mediana de la edad fue 71,4 y 55,6 % fueron mujeres. El bajo rendimiento físico (SPPB ≤ 6) fue de 10,0% a gran altitud y 19,4% en la costa (p<0,05). Los factores asociados con un bajo rendimiento físico fueron ser de costa (RPa: 2,10; IC95%: 1,02-4,33), tener una percepción de mala salud (RPa: 2,48; IC95%: 1,21-5,08), tener hipertensión arterial (RPa: 1,73; IC95%: 1,01-2,98), tener mayor edad (RPa: 1,04; IC95%: 1,01-1,07), mientras que ser agricultor (RPa: 0,49; IC95%: 0,25-0,97), y ser independiente (RPa: 0,37; IC95%: 0,20- ,072) serían factores protectores. Asimismo, se encontró que los pobladores de la costa tienen 0,86 puntos menos en el SPPB total que los de gran altitud (p=0,004). Conclusiones. Existe asociación entre residir en altura y RF en adultos mayores. La prevalencia de bajo RF en los adultos mayores de zonas rurales a nivel del mar es dos veces mayor en comparación a los que viven en comunidades rurales de altura. / Introduction. Living in high altitudes mandates that villagers adapt biologically and socially to the environment. The objective of this study was to determine the difference in physical performance (PP) in rural populations at sea level and at high altitude. Material and methods. A cross-sectional study was conducted in rural communities in Ancash, Peru, located at 3345 meters above sea level (m.a.s.l.) and also in communities located in coastal areas at 6 m.a.s.l. PP was measured by the Short Physical Performance Battery (SPPB) and other associated factors. Adjusted prevalence ratios (aPR) were calculated. Results. 130 older adults were assessed in the high altitude communities and 129 on the coast. The median age was 71.4 and 55.6% were female. Low physical performance (SPPB ≤ 6) was 10.0% at high altitude and 19.4% on the coast (p <0.05). Factors associated with low physical performance were residing at the coast (aPR: 2.10, 95% CI 1.02 to 4.33), self-reported poor health (aPR: 2.48, 95% CI 1.21 -5.08), hypertension (aPR: 1.73, 95% CI 1.01 to 2.98), and age (aPR: 1.04, 95% CI 1.01 to 1.07), while being a farmer (aPR: 0.49, 95% CI 0.25 to 0.97), and being independent (aPR: 0.37, 95% CI 0,20-, 072) were found to be protective factors. We also found that the inhabitants of the coast have on average a 0.86 point lower total SPPB than the high altitude ones (p = 0.004). Conclusions. There is an association between altitude of residence and PP in older adults. The prevalence of low PP in older adults in rural areas at sea level is twice as high compared to those living in high altitude rural communities.

This thesis describes experiments to investigate high-altitude relight of a lean direct injection (LDI) combustor. The features that make LDI technology less polluting in terms of NOx compared to conventional combustors are expected to impede relight performance. Therefore an improved understanding of ignition behaviour is required to ensure that stringent relight requirements can be satisfied. Realistic operating conditions are simulated in a ground-based test facility. The application of laser diagnostics presents particular difficulties due to the large quantities ofliquid fuel that impinge on the combustor walls during relight. Advances are made in the application of planar laser-induced fluorescence (PLIF) to monitor fuel placement in a combustor under these conditions. A novel apparatus is developed to deliver a laser sheet to the combustion chamber while protecting all optical surfaces from contamination. The PLIF images are compared with the cold flow field obtained from CFD modelling. These results indicate that fuel becomes trapped inside the central recirculation zone in highconcentrations. High-speed flame imaging performed simultaneously with the PLIF measurements provides important insights into the motion and breakup of flame during relight. An algorithm developed to track the flame activity reveals that the initial spark kernel is convected downstream, before breaking apart and moving upstream towards a recovery origin close to the fuel injector. Analysis of many ignition events has revealed several distinct modes of ignition failure.

Real world exposures to physiologically and/or psychologically stressful environments are often multifactorial. For example, high-altitude typically combines exposure to hypobaric hypoxia, solar radiation and cold ambient temperatures, while sea level thermal stress is often combined with supplementary or transient stressors such as rain, solar radiation and wind. In such complex environments, the effect of one stressor on performance may be subject to change, simply due to the presence of another independent stressor. Such differential influences can occur in three basic forms; additive, antagonistic and synergistic, each term defining a fundamental concept of inter-parameter interactions. As well as the natural occurrence of stressors in combination, understanding interactions is fundamental to experimentally modelling how multiple physiological strains integrate in their influence on or regulation of - exercise intensity. In this thesis the current literature on neuromuscular fatigue and the influence of thermal and hypoxic stress is reviewed (Chapter 1). This is followed by an outline of the methodological developments used in the subsequent experiments (Chapter 2). In the first experimental study (Chapter 3) a novel approach was adopted to investigate the combined effect of muscle cooling and hypoxia on neuromuscular fatigue in humans. The results showed that the neuromuscular system s maximal force generating capacity declined by 8.1 and 13.9% during independent cold and hypoxic stress compared to control. Force generation decreased by 21.4% during combined hypoxic-cold compared to control, closely matching the additive value of hypoxia and cold individually (22%). This was also reflected in the measurement of mechanical fatigue (electromechanical ratio), demonstrating an additive response during combined hypoxic-cold. From this study, it was concluded that when moderate hypoxia and cold environmental temperatures are combined during low intensity exercise, the level of fatigue increases additively with no interaction between these stressors. Before conducting a more complex investigation on combined stressors, a better understanding of the role of muscle temperature on central fatigue - i.e. voluntary muscle activation via the afferent signalling pathways was sought. The focus of Chapter 4 was to quantify the relationship between muscle temperature and voluntary muscle activation (central fatigue) across a wide range of temperatures. The primary finding was that different muscle temperatures can induce significant changes in voluntary activation (0.5% reduction per-degree-centigrade increase in muscle temperature) when neural drive is sustained for a prolonged effort (e.g. 120-s); however this effect is not exhibited during efforts that are brief in duration (e.g. 3-s). To further explore this finding, Chapter 5 investigated the effect of metaboreceptive feedback at two different muscle temperatures, using post-exercise muscle ischemia, on voluntary activation of a remote muscle group. The results showed that at the same perceived mental effort, peripheral limb discomfort was significantly higher with increasing muscle temperature (2% increase per-degree-centigrade increase). However any influence of increased muscle temperature on leg muscle metaboreceptive feedback did not appear to inhibit voluntary muscle activation - i.e. central control - of a remote muscle group, as represented by an equal force output and voluntary activation in the thermoneutral, contralateral leg. In Chapter 6, the psycho-sensory effects of changes in muscle temperature on central fatigue during dynamic exercise were investigated. During sustained dynamic exercise, fatigue development appeared to occur at a faster rate in hot muscle (4% increase per-degree-centigrade increase) leading to a nullification of the beneficial effects of increased muscle temperature on peak power output after a period of ~60-s maximal exercise. In support of previous studies using isometric exercise (Chapter 4 and 6), participants reported significantly higher muscular pain and discomfort in hot muscle compared to cooler muscle during dynamic exercise (2 and 1% increase per-degree-centigrade increase respectively), however this did not result in a lower power output. From Chapters 4, 5 and 6 it was concluded that in addition to faster rates of metabolite accumulation due to cardiovascular strain, it is possible that a direct sensitisation of the metaboreceptive group III and IV muscle afferents occurs in warmer muscle. This likely contributes to the reduction in voluntary muscle activation during exercise in the heat, while it may attenuate central fatigue in the cold. It was also interpreted that muscle afferents may have a similar signalling role to cutaneous sensory afferents; the latter of which are recognised for their role in providing thermal feedback to the cognitive-behavioural centres of the brain and aiding exercise regulation under thermal stress. The impact of body core and active muscle temperature on voluntary muscle activation represented a similar ratio (5 to 1 respectively) to the temperature manipulated (single leg) to non-temperature manipulated mass (rest of body) in Chapters 4, 5 and 6. This indicates that voluntary muscle activation may also be regulated based on a central meta-representation of total body heat content i.e. the summed firing rates of all activated thermoreceptors in the brain, skin, muscle, viscera and spine. Building on the initial findings of Chapter 3, Chapter 7 investigated the causative factors behind the expression of different interaction types during exposure to multi-stressor environments. This was achieved by studying the interaction between thermal stress and hypoxia on the rate of peripheral and central fatigue development during a high intensity bout of knee extension exercise to exhaustion. The results showed that during combined exposure to moderate hypoxia and mild cold, the reductions in time to exhaustion were additive of the relative effects of hypoxia and cold independently. This differs from the findings in Chapter 3, in which fatigue was additive of the absolute effects of cold and hypoxia. In contrast, combining moderate hypoxia with severe heat stress resulted in a significant antagonistic interaction on both the absolute and relative reductions in time to exhaustion i.e. the combined effect being significantly less than the sum of the individual effects. Based on the results in Chapter 7, a quantitative paradigm for understanding of systematic integration of multifactorial stressors was proposed. This is, that the interaction type between stressors is influenced by the impact magnitude of the individual stressors effect on exercise capacity, whereby the greater the stressors impact, the greater the probability that one stressor will be cancelled out by the other. This is the first study to experimentally model the overarching principles characterising the presence of simultaneous physiological strains, suggesting multifactorial integration be subject to the worst strain takes precedence when the individual strains are severe.

L'objectif de cette thèse est l'étude de la plasticité phénotypique du sapin pectiné à l'aide de l'approche architecturale. Ces travaux se placent dans le contexte plus large de compréhension du développement des plantes pérennes en lien avec leur environnement et l'impact des changements climatiques en région méditerranéenne. Pour mener à bien ces objectifs, des études ont été menées ex-situ en conditions contrôlées (gradient d'ombrage et de disponibilité en eau) et in-situ au Mont Ventoux (gradient d'ombrage et altitudinal). Ces études ont consisté en l'analyse de la variabilité de différents traits architecturaux, généralement mesurés à l'échelle de la pousse annuelle, en lien avec l'architecture et l'environnement. Ces études ont permis de caractériser quantitativement le développement du sapin jusqu'à l'expression durable de la sexualité et de quantifier la réponse plastique à l'environnement lumineux, hydrique et climatique. Enfin, ce travail a permis d'approfondir le concept de plasticité architecturale et ses implications. / The aim of this work is to assess silver fir phenotypic plasticity with an architectural approach. This work take place in the context of understanding perennial plant development linked with their environment and the context of climate change in the Mediterranean region.For this, ex-situ (shading and watering treatments) and in-situ (shading and elevation gradients) studies were performed. They consist of the study of architectural traits variability, mainly measured at annual shoot scale, linked with plant architecture and environment.The results are the quantification of silver firs development up to reproductive tree and the quantification of plastic responses to light and hydric environment and climate. The concept of architectural plasticity and it consequences was also discussed.

The spleen has been shown to contract in apneic situations in humans as well as in other diving mammals, expelling its stored red blood cell content into circulation. This natural blood boosting may increase the circulating hemoglobin concentration (Hb) by up to 10%, which would enhance the oxygen carrying capacity and likely increase performance. However, the triggers of this response in humans have not been fully clarified. Study I was therefore focused on the effect of hypoxia as a trigger of spleen contraction. It was found that 20 min of normobaric hypoxic breathing evoked a substantial reduction in spleen volume showing that hypoxia is an important trigger for spleen contraction. Knowing the role of hypoxia, Study II compared two different hypoxic situations – a 2 min apnea and 20 min normobaric hypoxic breathing – which resulted in the same level of arterial hemoglobin desaturation. Apnea evoked a twice as great spleen volume reduction, implying that variables other than hypoxia were likely involved in triggering spleen contraction. This may be hypercapnia which is present during apnea but not during normobaric hypoxic breathing. Study III therefore investigated the effects of breathing gas mixtures containing different proportions of CO2 prior to maximal apneas. Pre-breathing mixtures with higher percentages of CO2 resulted in greater spleen contraction, thus demonstrating hypercapnia's likely role as a trigger in addition to hypoxia. Study IV explored whether an all-or-nothing threshold stimulus for triggering spleen contraction existed, or if contraction was graded in relation to the magnitude of triggering stimuli. Exercise was therefore performed in an already hypoxic state during normobaria. Rest in hypoxia produced a moderate spleen volume reduction, with an enhanced spleen contraction resulting after hypoxic exercise, with a concomitant increase in Hb. This implies that spleen contraction is a graded response related to the magnitude of the stimuli. This could be beneficial in environments with varying oxygen content or work loads. Study V examined the possibility that spleen contraction is part of the acclimatization to altitude, during an expedition to summit Mt Everest. The long-term high altitude exposure, combined with physical work on the mountain, had no effects on resting spleen volume but resulted in a stronger spleen contraction, when provoked by apnea or exercise. This indicates that acclimatization to altitude may enhance the contractile capacity of the spleen, which may be beneficial for the climber. From these studies I concluded that hypoxia is an important trigger for spleen contraction but that hypercapnia also contributes in apneic situations. The spleen contraction likely provides a graded expulsion of erythrocytes in response to these stimuli, causing a temporary increase in gas storage capacity that may facilitate activities such as freediving and climbing. The storage of erythrocytes during rest serves to reduce blood viscosity, which would also be beneficial for the climber or diver. The human spleen contraction appears to become stronger with acclimatization, with beneficial effects at altitude. Such an upgraded response could be beneficial both in sports and diseases involving hypoxia.

Orientador: Eleonore Zulnara Freire Setz / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-26T19:20:24Z (GMT). No. of bitstreams: 1 Sakane_KarinaKoibuchi_M.pdf: 3375558 bytes, checksum: b467da20c9db67f87557bc52b120d3bb (MD5) Previous issue date: 2015 / Resumo: A distribuição de espécies pode ser influenciada por diversos fatores. Pequenos mamíferos são bons modelos para estudos de distribuição e uso de espaço. São abundantes, de fácil captura, utilizam o espaço de diferentes formas e apresentam hábitos alimentares diversos. Realizamos o presente estudo na Reserva Biológica da Serra do Japi, Jundiaí-SP e tivemos como principais objetivos: (I) Investigar a riqueza de espécies presente na área e realizar um resumo da ecologia e história natural de cada espécie capturada (II) Analisar, ao longo de um gradiente altitudinal, a influência de diferentes fatores (temperatura, disponibilidade de alimentos, cobertura de solo, obstrução de dossel e obstrução vertical) na riqueza e abundância de espécies (III) Investigar a influência dos mesmos fatores citados anteriormente na composição de espécies. Na Reserva Biológica da Serra do Japi foram capturadas 11 espécies: Akodon sp., Oligoryzomys nigripes, Brucepattersonius sp., Delomys sublineatus, Thaptomys nigrita, Juliomys pictipes, Blarinomys breviceps, Didelphis aurita, Monodelphis scalops, Gracilinanus microtarsus e Monodelphis sp.n. A Reserva apresenta espécies que atuam como bons indicadores de qualidade ambiental e espécies endêmicas da Mata Atlântica, reforçando a sua importância na conservação. A riqueza foi significativamente maior na altitude intermediária. A única variável que apresentou influência significativa na riqueza, abundância e composição de espécies foi a cobertura por galhos caídos e arbustos de até 1 m (cobertura do solo). A maior porcentagem de cobertura do solo aumenta número de abrigos disponíveis, permitindo maior diferenciação de nicho e coexistência de diferentes espécies. Galhos caídos e arbustos ainda podem estar relacionados à redução de efeitos da competição e da predação / Abstract: Many factors can influence the distribution of species. Small mammals are good models for studies of distribution and use of space. They are abundant, easy to capture, use space differently and have different types of diets. This study was conducted in the Biological Reserve of Serra do Japi, Jundiaí-SP and had as aims: (I) Investigate the richness and get a summary of the ecology and natural history of each species of Reserve (II) research the influence of different factors (temperature, food availability, ground cover, canopy and vertical obstruction) in richness and abundance of species along a altitudinal gradient (III) Investigate the influence of the same factors mentioned before in the composition of small mammals. We found 11 species: Akodon sp., Oligoryzomys nigripes, Brucepattersonius sp., Delomys sublineatus, Thaptomys nigrita, Juliomys pictipes, Blarinomys breviceps, Didelphis aurita, Monodelphis scalops, Gracilinanus microtarsus and Monodelphis sp.n. The Biological Reserve of Serra do Japi has species that act as good indicators of environmental quality and also has endemic species of the Atlantic Forest. The richness was significantly higher the intermediate altitude. The only variable that showed significant influence on richness, abundance and species composition was fallen twigs and branches up to 1 m (ground cover). The highest percentage of ground cover increases the available resources, allowing niche differentiation and coexistence of different species. Fallen twigs and branches can also be related to decrease the effects of competition and predation / Mestrado / Ecologia / Mestra em Ecologia

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-03-01T00:55:21Z No. of bitstreams: 1 DISSERTA??O augusto.pdf: 990945 bytes, checksum: 0ffa3c6ca52f5bfb881523a9ecb67d91 (MD5) / Made available in DSpace on 2016-03-01T00:55:21Z (GMT). No. of bitstreams: 1 DISSERTA??O augusto.pdf: 990945 bytes, checksum: 0ffa3c6ca52f5bfb881523a9ecb67d91 (MD5) Previous issue date: 2013-02-04 / The approach to the study of complex networks used for networks of interactions allows the identification of emergent properties such as nestdness, modularity and specialization. Consequently, we hypothesize that mutualistic networks between plants and butterflies visiting flowers in higher altitudes are characterized by few species, with low feeding selectivity. We developed the study using two organizational levels: local and global. The local level comprised mutualistic networks in two hills located in the Chapada Diamantina. The global level comprised mutualistic networks in different regions of the globe. For each network, we evaluated the relationship between altitude, modularity, nestdness and specialization. No network metric shoed a consistent change associated with altitudinal variation, not in the local and global levels. Thus, the structure of interaction networks between butterflies visiting the flowers and plants does not respond to changes in altitude, what we are left understand what factors may be determinants for this interaction. / A abordagem do estudo de redes complexas utilizada para as redes de intera??es permite a identifica??o de propriedades emergentes tais como o aninhamento, modularidade e especializa??o. Nesse sentido, propomos a hip?tese de que redes de intera??es entre borboletas visitantes florais e plantas em altas altitudes ser?o caracterizadas por poucas esp?cies, com baixa seletividade alimentar. Nossas expectativas s?o de que, ao longo de uma montanha (n?vel local), tais redes ser?o 1) menos modulares; 2) menos aninhadas e 3) compostas por esp?cies generalistas na regi?o do topo, quando comparadas com redes localizadas nas regi?es mais basais. Esperamos encontrar esse mesmo padr?o ao avaliar redes descritas em diferentes altitudes ao longo do globo (n?vel global). Realizamos o estudo utilizando dois n?veis organizacionais: local e global. O n?vel local envolveu dois morros situados na Chapada Diamantina e para cada morro, duas altitudes. O n?vel global envolveu redes de intera??es em v?rias partes do mundo com altitudes diferentes. Para cada rede avaliamos a associa??o entre altitude, modularidade, aninhamento e especializa??o. Nenhuma das tr?s m?tricas de rede revelou mudan?a consistente em rela??o ?s duas altitudes dos morros ou mesmo para a avalia??o global. Desta forma, a estrutura de redes de intera??o entre borboletas visitantes florais e plantas n?o responde a varia??es de altitude, o que nos resta entender quais os fatores que podem ser determinantes para essa intera??o.