61 |
Efeitos de dois modelos de treinamento aeróbico realizados em diferentes meios sobre parâmetros cardiorrespiratórios, hormonais e metabólicos de pacientes com diabetes mellitus tipo 2 – um ensaio clínico randomizado / Effects of two models of aerobic training performed in different environments on cardiorespiratory, hormonal and metabolic parameters in patients with type 2 diabetes mellitus - a randomized clinical trialDelevatti, Rodrigo Sudatti January 2013 (has links)
Objetivo: Analisar os efeitos crônicos de dois modelos de treinamento aeróbico realizados em ambiente aquático e terrestre sobre parâmetros cardiorrespiratórios, funcionais, metabólicos, hormonais e de qualidade de vida em pacientes com diabetes mellitus tipo 2 (DMT2). Materiais e métodos: Pacientes com DMT2 foram randomizados em um grupo de treinamento aeróbico aquático (n = 11) ou um grupo de treinamento aeróbico terrestre (n = 10). Ambos os programas apresentaram uma periodização de treinamento similar, diferindo basicamente no meio em que foram realizados. Estes programas tiveram duração de 12 semanas, sendo adotado o método intervalado, com intensidades variando entre 85 e 100% do segundo limiar ventilatório (LV2) e duração total das sessões de 45 minutos. Foram avaliados parâmetros cardiorrespiratórios, funcionais, bioquímicos e de qualidade de vida, todos nos momentos pré e pós-treinamento. Os dados foram descritos pelos valores de média e desvio-padrão. A comparação das variáveis dependentes entre grupos no momento pré-intervenção foi realizada através do teste t de Student para amostras independentes ou através do teste de qui-quadrado. A análise de variância de medidas repetidas com fator grupo foi usada para comparações entre os diferentes momentos em ambos os grupos, adotando-se um nível de significância (α) de 0,05. Resultados: As intervenções propostas resultaram em um aumento do percentual do consumo de oxigênio no segundo limiar ventilatório - %VO2LV2 (p = 0,032) e uma redução da frequência cardíaca de repouso - FCrep (p = 0,011) em ambos os grupos, não alterando significativamente as variáveis cardiorrespiratórias consumo de oxigênio de pico (VO2pico), consumo de oxigênio no segundo limiar ventilatório (VO2LV2), pressão arterial sistólica (PAS) e pressão arterial diastólica (PAD). A mobilidade funcional também melhorou em ambos os grupos, pois estes diminuiram seus tempos médios de realização do Timed Up and Go test em velocidade habitual (p = 0,019) e máxima (p = 0,014). Analisando os desfechos glicêmicos, ambos os grupos apresentaram uma redução significativa nos níveis de hemoglobina glicada – HbA1c (p = 0,035) e não sofreram alterações significativas nos níveis de glicemia de jejum (GJ) e glicemia pós-prandial (GPP) após as intervenções propostas. Este comportamento foi encontrado também na análise dos valores de insulina de jejum (IJ) e resistência a insulina (HOMA-IR), que apresentaram apenas diferença entre os grupos (IJ, p = 0,039 e HOMA-IR, p = 0,032). No perfil lipídico, apenas os valores de triglicerídeos (TG) não demonstraram alterações após o treinamento, tendo ocorrido redução significativa nos níveis de colesterol total - CT (p = 0,054), lipoproteína de alta densidade - HDL (p < 0,001) e lipoproteína de baixa densidade - LDL (p = 0,034). O mesmo comportamento ocorreu na atividade da renina plasmática - ARP (p = 0,035) e nos níveis de proteína C-reativa ultra-sensível - PCRus (p = 0,001). Ambos os grupos também apresentaram melhora significativa após o período de treinamento na qualidade de vida relacionada aos domínios físico (p = 0,019) e psicológico (p = 0,027), sem alterações significativas na qualidade de vida geral e nos demais domínios analisados. Conclusões: O treinamento aeróbico proposto ocasionou benéficos efeitos no %VO2LV2, na FCrep, em parâmetros funcionais, no controle glicêmico, nos níveis de CT e LDL, na inflamação sistêmica, na ARP e na qualidade de vida relacionada aos domínios físico e psicológico, independente do meio em que foi realizado. No entanto, mostrou-se inespecífico para melhorar os níveis de HDL e não impactou significativamente a maioria dos parâmetros cardiorrespiratórios, assim como os níveis insulinêmicos e a qualidade de vida geral e nos domínios ambiental e relações sociais. / Aim: To analyse the chronic effects of two aerobic-training models performed in water and on dry land on cardiorespiratory, functional, metabolic, hormonal and quality-of-life parameters in patients with type 2 diabetes mellitus (T2DM). Materials and methods: Patients with T2DM were randomized to a group of aquatic aerobic training (n = 11) or a group of aerobic training on land (n = 10). Both programs had similar training periodization, with training environment being the main difference between them. The training programs had a duration of 12 weeks and adopted the interval-training method, with intensities ranging between 85 and 100% of second ventilatory threshold (VT2) and total duration of 45 minute per session. We assessed cardiorespiratory, functional, biochemical and quality-of-life parameters before and after the intervention. Data were described by mean and standard deviation. Comparisons between groups in the pre-intervention were performed using the Student t test for independent samples variables and the chi-square test. The repeated-measures analysis of variance with group as a factor was used for comparisons between pre- and post-training values. A significance level (α) of 0.05 was adopted for all analyses. Results: The proposed interventions caused an increase in percentage of oxygen consumption at second ventilatory threshold - %VO2VT2 (p = 0.032) and a reduction in rest heart rate - HR (p = 0.011) in both groups, while no significant alterations were found in the cardiorespiratory variables peak oxygen consumption (VO2peak), oxygen consumption at second ventilatory threshold (VO2VT2), systolic blood pressure (SBP) and diastolic blood pressure (DBP). Functional mobility was also improved in both groups, since average time for completing the Timed up and Go test in usual (p = 0.019) and maximal (p = 0.014) speed was decreased. Regarding the glycemic outcomes, both groups showed a significant reduction in glycated hemoglobin levels – HbA1c (p = 0.035) and no significant changes in the levels of fasting glucose (FG) and postprandial glucose (PPG) after the interventions. The values of fasting insulin (FI) and insulin resistance (HOMA-IR) showed differences only between the groups (FI, p = 0.039 and HOMA-IR, p = 0.032). Considering lipid profile variables, only triglycerides (TG) showed no change after training, with total cholesterol level – TC (p = 0.054), high density lipoprotein – HDL (p <0.001) and low density lipoprotein – LDL (p = 0.034) being significantly reduced. The same pattern was observed for the plasmatic rennin activity - PRA (p = 0.035) and high-sensitivity C-reactive protein - CRP levels (p = 0.001). Both groups also showed a significant improvement in quality of life related to the physical (p = 0.019) and psychological (p = 0.027) domains in response to the intervention, although there were no significant changes in overall quality of life and in the other domains analyzed. Conclusions: The proposed aerobic training programs elicited beneficial effects in %VO2VT2, rest HR, functional parameters, glycemic control, levels of TC and LDL, systemic inflammation, PRA and quality of life related to physical and psychological domains. These benefits did not depend on training environment. Nevertheless, this training method appears to be nonspecific for improvements in HDL levels and did not affect significantly the majority of cardiorespiratory parameters, as well as insulin levels, overall quality of life and quality of life in environmental and social relations.
|
62 |
Oxygen saturation surrounding deep-water formation events in the Labrador Sea from Argo-O2 dataWolf, Mitchell 04 August 2017 (has links)
Deep-water formation supplies oxygen-rich water to the deep sea, spreading throughout the ocean via the global thermohaline circulation. Models suggest that gases in newly formed deep-water do not come to equilibrium with the atmosphere. However, direct measurements during wintertime convection are scarce, and the controls over the extent of this disequilibria are poorly quantified. Here we show that oxygen is consistently undersaturated at -6.3% to -7.6% in the Labrador Sea at the end of convection, when convection reaches deeper than 800 m. Deeper convection resulted in greater undersaturation while convection lasting later in the year resulted in values closer to equilibrium, from which we produce a predictive relationship. We use dissolved oxygen data from six profiling Argo floats in the Labrador Sea between 2003 to 2016, allowing direct observations of wintertime convection. Four of the six optode oxygen sensors displayed in situ drift of -2.98 μmol O2 kg-1 year-1 on average, which we corrected to stable deep-water oxygen values from repeat hydrography. Observations of low oxygen intrusions during restratification and a simple mixing calculation demonstrate that lateral processes act to lower the oxygen inventory of the central Labrador Sea. This suggests that the Labrador Sea is a net sink for atmospheric oxygen, but uncertainties in parameterizing gas exchange limit our ability to quantify the net uptake. Our results constrain the initial oxygen concentration of Labrador Sea Water and allow more precise estimates of oxygen utilization and nutrient regeneration in this water mass. / Graduate
|
63 |
Shelf-edge deltas : stratigraphic complexity and relationship to deep-water depositionDixon, Joshua Francis 08 November 2013 (has links)
This research investigates the character and significance of shelf-edge deltas within the sedimentary source-to-sink system, and how variability at the shelf edge leads to different styles of deep-water deposition. Because the shelf-edge represents one of the key entry points for terrigenous sediment to be delivered into the deep water, understanding of the sedimentary processes in operation at these locations, and the character of sediment transported through these deltas is critical to understanding of deep-water sedimentary systems. The research was carried out using three datasets: an outcrop dataset of 6000 m of measured sections from the Permian-Triassic Karoo Basin, South Africa, a 3D seismic data volume from the Eocene Northern Santos Basin, offshore Brazil and a dataset of 29 previously published descriptions of shelf-edge deltas from a variety of locations and data types.
The data presented highlight the importance of sediment instability in the progradation of basin margins, and deep-water transport of sediment. The strata of the Karoo Basin shelf margin represent river-dominated delta deposits that become more deformed as the shelf-edge position is approached. At the shelf edge, basinward dipping,
offlapping packages of soft-sediment-deformed and undeformed strata record repetitive collapse and re-establishment of shelf-edge mouth bar packages. The offlapping strata of the Karoo outcrops record progradation of the shelf margin through accretion of the shelf-edge delta, for over 1 km before subsequent transgression. The Eocene Northern Santos Basin shelf margin, in contrast, exhibits instability features which remove kilometers-wide wedges of the outer shelf that are transported to the basin floor to be deposited as mass-transport packages. In this example, shelf-edge progradation is achieved through „stable. accretion of mixed turbidites and contourites.
The data also emphasize the importance of the role of shelf-edge delta processes in the delivery of sediment to the basin floor. A global dataset of 29 examples of shelf-edge systems strongly indicates that river domination of the shelf-edge system (as read from cores, well logs or isopach maps) serves as a more reliable predictor of deep-water sediment delivery and deposition than relative sea level fall as traditionally read in shelf-edge trajectories or sequence boundaries. / text
|
64 |
パラオ海溝の深海6500mに存在する石灰岩体の溶解Otsuji, Naho, Kitazato, Hiroshi, Oguri, Kazumasa, Fujioka, Kantaro, Matsuzaki, Hiroyuki, Nakamura, Toshio, Wada, Hideki, Tsuboi, Tatsuya, 北里, 洋, 小栗, 一将, 藤岡, 換太郎, 大辻, 菜穂, 松崎, 浩之, 中村, 俊夫, 和田, 秀樹, 坪井, 辰哉 03 1900 (has links)
名古屋大学年代測定総合研究センターシンポジウム報告
|
65 |
Dálkově řízená sonda pro průzkum zatopených krasových oblastí / Remote Operated Probe for Deep-water Cave ExplorationŠiroký, Daniel January 2009 (has links)
Předkládaná práce se zabývá návrhem a konstrukcí dálkově řízené sondy pro průzkum zatopených krasových oblastí. Cílem práce je zhotovení cenově přijatelné sondy pro speleologický výzkum. Soustava senzorů a dálkově řízený kamerový systém umožňuje pořízení záběrů z velkých hloubek, které lze později analyzovat.
|
66 |
Simple Models For Predicting Dune Erosion Hazards Along The Outer Banks Of North CarolinaWetzell, Lauren McKinnon 13 November 2003 (has links)
Hurricane hazards result from the combined processes of wind, waves, storm surge, and overwash (Lennon et al., 1996). Predicting the severity of these hazards requires immense effort to quantify the processes and then predict how different coastal regions respond to them. A somewhat simpler, but no less daunting task is to begin to predict the hazards due to potential erosion of barrier islands. A four-part scale has been developed by Sallenger (2000) to provide a framework for understanding how barrier islands might respond during extreme storm events. These four regimes describe how beach and dune elevations interact with surge and wave runup. This study will produce estimates of potential hazards through combining lidar surveys of dune elevation with modeled elevations of storm water levels.
Direct measurements of maximum wave heights during hurricanes are rare. We evaluated three simple equations proposed by Kjerfve (1986), Young (1988), and Hsu (1998) to forecast the maximum wave height (Hmax) generated by three 1999 hurricanes. Model results were compared to wave data recorded by the National Oceanic and Atmospheric Administration (NOAA) wave rider buoys. The radius of maximum winds, wind speed, forward velocity, distance from buoy to the storm's eye-wall (r), and buoy's position relative to the quadrant of the storm (Q) were found to have significant and direct roles in evaluating recorded hurricane induced wave heights (H) and thus, were individually examined for each comparison. The implications of the r and Q on H were assessed when determining the overall effectiveness of the modelers' equations.
Linear regression analyses tested the accuracy of each modeled prediction of the Hmax, comparing it to the observed wave heights. Three statistical criteria were used to quantify model performance. Hsu's model was the most reliable and useful forecasting technique.
Despite the predictive skill of Hsu's model, direct observations of the maximum wave conditions, when available and appropriate, are preferred as inputs for SWAN, a 3rd generation shoaling wave model. Outputs from SWAN are used to calculate the empirical relationships for wave runup. For our test case, pre and post-storm topographies were surveyed as part of a joint USGS-NASA program using lidar technology. These data sets were used to calculate changes in the elevation and location of the dune crest (Dhigh) and dune base (Dlow) for the North Carolina Outer Banks. We hindcast potential coastal hazards (erosional hot spots) using the pre-storm morphology and modeled wave runup and compare those estimates to the measured results from the post-storm survey. Links among the existing topography and spatial variations in wave runup were found to be 95% correlated for the north-south and east-west facing barrier islands. Application of Sallenger's (2000) four-part Storm Impact Scale to the pre-storm Dhigh elevation survey and wave runup extremes (Rhigh and Rlow) were found to accurately predict zones of overwash and showed potential to forecast the inundation regime.
|
67 |
Deep water Gulf of Mexico pore pressure estimation utilizing P-SV waves from multicomponent seismic in Atlantis FieldKao, Jeffrey Chung-chen 08 September 2010 (has links)
Overpressure, or abnormally low effective pressures, is hazardous in drilling operations and construction of sea-bottom facilities in deepwater environments. Estimation of the locations of overpressure can improve safety in these operations and significantly reduce overall project costs. Propagation velocities of both seismic P and S wave are sensitive to bulk elastic parameters and density of the sediments, which can be related to porosity, pore fluid content, lithology, and effective pressures. Overpressured areas can be analyzed using 4C seismic reflection data, which includes P-P and P-SV reflections. In this thesis, the effects on compressional (P) and shear (S) wave velocities are investigated to estimate the magnitude and location of excess pore pressure utilizing Eaton’s approach for pressure prediction (Eaton, 1969).
Eaton’s (1969) method relates changes in pore pressure to changes in seismic P-wave velocity. The underlying assumption of this method utilizes the ratio of observed P-wave velocity obtained from areas of both normal and abnormal pressure. This velocity ratio evaluated through an empirically determined exponent is then related to the ratio of effective stress under normal and abnormal pressure conditions. Effective stress in a normal pressured condition is greater than the effective stress value in abnormally overpressured conditions. Due to an increased sensitivity of variations in effective pressure to seismic interval velocity, Ebrom et al. (2003) employ a modified Eaton equation to incorporate the S-wave velocity in pore pressure prediction.
The data preparation and subsequent observations of seismic P and S wave velocity estimates in this thesis represent a preliminary analysis for pore pressure prediction. Six 2D receiver gathers in the regional dip direction are extracted from six individual ocean-bottom 4C seismic recording nodes for P-P and P-SV velocity analysis. The receiver gathers employed have minimal pre-processing procedures applied. The main processing steps applied were: water bottom mute, 2D rotation of horizontal components to SV and SH orientation, deconvolution, and frequency filtering. Most the processing was performed in Matlab with a volume of scripts designed by research scientists from the University of Texas, Bureau of Economic Geology.
In this thesis, fluid pressure prediction is estimated utilizing several 4C multicomponent ocean-bottom nodes in the Atlantis Field in deepwater Gulf of Mexico. Velocity analysis is performed through a ray tracing approach utilizing P-P and P-SV registration. A modified Eaton’s Algorithm is then used for pore pressure prediction using both P and S wave velocity values.
I was able to successfully observe both compressional and shear wave velocities to sediment depths of approximately 800 m below the seafloor. Using Hamilton (1972, 1976) and Eberhart-Phillips et al. (1989) regressions as background depth dependent velocity values and well-log derived background effective pressure values from deepwater Gulf of Mexico, I am able to solve for predicted effective pressure for the study area. The results show that the Atlantis subsurface study area experiences a degree of overpressure. / text
|
68 |
Zooplankton community structure and functioning in the North Western Mediterranean sea / Structure et fonctionnement des communautés zooplanctoniques de Méditerranée Nord-OccidentaleDonoso Ferez, Katty 11 July 2017 (has links)
La Méditerranée Nord-Occidentale (MNO) est marquée par un processus de formation d’eau profonde en hiver qui induit une forte floraison phytoplanctonique au printemps. L'objectif de cette thèse a été de caractériser la dynamique de la communauté mesozooplanctonique à l'échelle régionale de la MNO, y compris dans la zone de convection profonde (ZCP), en évaluant ses stocks, sa composition taxonomique, sa structure en taille et ses liens trophiques avec le phytoplancton, en relation avec l'environnement hydro-biogéochimique. Trois campagnes océanographiques ont été menées en saisons contrastées: hiver, printemps et été, fournissant un jeu de données unique à cette échelle régionale. Le zooplancton est caractérisé par de faibles abondances et biomasses en hiver, surtout dans la ZCP, puis par une augmentation générale printanière, en abondance et en biomasse. Des différences spatiales s’observent, la ZCP présentant les plus forts changements de biomasse de l’hiver au printemps. Les valeurs d'été sont similaires aux valeurs hivernales et sont assez homogènes dans la zone d'étude. L'impact du broutage estimé n'est pas suffisant pour contrôler globalement la floraison printanière. Cependant, au printemps, toute la MNO, à l'exception de la ZCP, subit un contrôle top-down du zooplancton sur le phytoplancton, tandis que dans la ZCP, les valeurs de chlorophylle-a restent élevées malgré la forte demande en carbone du zooplancton, ce qui indique un contrôle bottom-up. Cette étude montre que la ZCP est probablement une zone d'intense transfert d'énergie vers les niveaux trophiques supérieurs ainsi que d'export de matière organique en MNO. / The North-Western Mediterranean Sea (NWMS) is characterized by a deep water convection process in winter, which induces a large phytoplankton bloom. The main objective of this thesis was to characterize the dynamics of the mesozooplankton community at the regional scale of NWMS including the deep convection zone (DCZ), by assessing its stocks, taxonomy and size structure, and by evaluating its phytoplankton-zooplankton trophic links in connection to the hydrological and biogeochemical environment. Three oceanographic cruises were conducted to map the NWMS in contrasting seasons: winter, spring, and summer. This represents a unique data set of zooplankton at this regional scale. The NWMS was characterized in winter by low zooplankton abundance and biomass. In spring, a general increase was found. Spatially DCZ was characterized by lowest stocks in winter and the highest in spring. In summer, biomass and abundance were similar to winter values and were quite homogenous over the study area. The estimated zooplankton grazing impact was not sufficient to globally control the spring phytoplankton bloom. However, in spring, all areas except the DCZ incurred top-down control by zooplankton on the phytoplankton stock. In the DCZ, the chlorophyll-a values remained high despite the high zooplankton biomass and carbon demand, indicating a sustained bottom-up control. This study indicates that the deep convection zone is likely an area of both enhanced energy transfer to higher trophic levels and organic matter export in NWMS.
|
69 |
Sedimentological Investigations of Paleo-Ice Sheet Dynamics in West AntarcticaKirshner, Alexandra 16 September 2013 (has links)
Modern Pine Island and Thwaites Glaciers, which both drain into Pine Island Bay, are some of the fastest moving portions of the cryosphere and may be the most unstable ice streams in Antarctica. I examined over 133 cores to conduct a detailed sedimentological facies analysis. These data, augmented by new radiocarbon and 210Pb dates, and bathymetric data, are used to reconstruct the post-LGM deglacial history of PIB and gain a better understanding of the causes of ice sheet retreat.
My results record a clear retreat stratigraphy in PIB composed of, from top to base; terrigenous sandy silt (plumite), pebbly sandy mud (ice-proximal glacimarine), and till. Initial retreat from the outer-continental shelf began shortly after the LGM and before 16.4 k cal yr BP, in response to rising sea level. Bedforms in outer PIB document episodic retreat in the form of back-stepping grounding zone wedges and are associated with proximal glacimarine sediments. A sub-ice shelf facies is observed in central PIB that spans ∼12.3–10.6 k cal yr BP. Widespread impingement of warm water onto the continental shelf caused an abrupt change from sub-ice shelf sedimentation to distal glacimarine sedimentation dominated by dispersal of terrigenous silt between 7.8 and 7.0 k cal yr BP. The uppermost sediments in Pine Island Bay were hydrodynamically sorted by meltwater plumes. Inner Pine Island Bay contains several large basins that are linked by channels. The most recent release of sediment coincides with rapid retreat of the grounding line, and has an order of magnitude greater flux relative to the entire unit, indicating episodic sedimentation. This is the first identification of a meltwater-derived deposit in Antarctica and demonstrates that punctuated meltwater-intensive glacial retreat occurred at least three times throughout the Holocene in this region.
Quartz sand grains were used to conduct an analysis of mode of transport for sediments in the Antarctic Peninsula region from the Eocene to present to record the onset of glaciation. Glacial transport imparts a unique suite of microtextures on quartz grains from high shear-stresses. Eocene samples are free of glacial influence. Late Eocene samples show the inception of glacially derived high-stress microtextures, marking the onset of alpine glaciation. Oligocene grains are similar to the late Eocene samples. Middle Miocene microtextures are characteristic of transport from far-field large ice sheets, originating from ice rafting from the West Antarctic Ice Sheet. The Pliocene and Pleistocene samples indicate the existence of the northern Antarctic Peninsula Ice Sheet at this time, consistent with other proxies.
|
70 |
Studies into the Initial Conditions, Flow Rate, and Containment System of Oil Field Leaks in Deep WaterHolder, Rachel 16 December 2013 (has links)
Oil well blow outs are investigated to determine methods to quickly and accurately respond to an emergency situation. Flow rate is needed to guide containment and dispersal operations. The Stratified Integral Multiphase Plume, SIMP, model was used to investigate the range of initial conditions available to integral modeling. Sensitivity to initial conditions is modest, but without experimental data at the appropriate scale the most accurate condition is unable to be determined. Flow rates are difficult to directly measure in blow out situations, so another method must be determined; therefore, sensitivity of several parameters to flow rate was also evaluated. Methane concentration in the first intrusion can be used in conjunction with velocity and trap height measurements to determine flow rate using an integral model. Plume width and temperature were determined to have little sensitivity. Separately, a containment dome was tested in the laboratory to determine if a full scale dome can be used to contain an oil leak in the field. The dome was found to have satisfactory entrapment in the designed position.
|
Page generated in 0.0726 seconds