936 resultados para Paramorphogenic form


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Von C. Engelke

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Von August Schütz

Relevância:

20.00% 20.00%

Publicador:

Resumo:

von Jos. L. Saalschütz

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Diabetes Mellitus is not a disease, but a group of diseases. Common to all types of diabetes is high levels of blood glucose produced from a variety of causes. In 2006, the American Diabetes Association ranked diabetes as the fifth leading cause of death in the United States. The complications and consequences are serious and include nephropathy, retinopathy, neuropathy, heart disease, amputations, pregnancy complications, sexual dysfunction, biochemical imbalances, susceptibility and sensitivity to many other diseases and in some cases death. ^ The serious nature of diabetes mellitus and its complications has compelled researchers to devise new strategies to reach population segments at high risk. Various avenues of outreach have been attempted. This pilot program is not unique in using a health museum as a point of outreach. However health museums have not been a major source of interventions, either. Little information was available regarding health museum visitor demographics, visitation patterns, companion status and museum trust levels prior to this pilot intervention. This visitor information will improve planning for further interventions and studies. ^ This thesis also examined prevalence data in a temporal context, the populations at risk for diabetes, the collecting agencies, and other relevant collected data. The prevalence of diabetes has been rapidly increasing. The increase is partially explained by refinement of the definition of diabetes as the etiology has become better understood. Increasing obesity and sedentary lifestyles have contributed to the increase, as well as the burdensome increase on minority populations. ^ Treatment options are complex and have had limited effectiveness. This would lead one to conclude that prevention and early diagnosis are preferable. However, the general public has insufficient awareness and education regarding diabetes symptoms and the serious risks and complications the disease can cause. Reaching high risk, high prevalence, populations is challenging for any intervention. During its “free family Thursdays” The Health Museum (Houston, Texas) has attracted a variety of ethnic patrons; similar to the Houston and Harris County demographics. This research project explored the effectiveness of a pilot diabetes educational intervention in a health museum setting where people chose to visit. ^

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Teen pregnancy is a continuing problem, bringing with it a host of associated health and social risks. Alternative school students are especially at risk, but are historically under-represented in research. This is especially problematic in that instruments are needed to guide effective intervention development, but psychometrics for these instruments cannot be assumed when used in new populations. Decisional balance from the transtheoretical model offers a framework for understanding condom decision making, but has not been tested with alternative school students. Using responses from 640 subjects from Safer Choices 2 (a school-based HIV/STD/pregnancy prevention program implemented in 10 urban, southwestern alternative schools), a decisional balance scale for condom use was examined. A two-factor, mildly correlated model fit the data well. Tests of invariance examined scale functioning within gender and racial/ethnic groups. The underlying structure varied slightly based on subgroup, but on a practical level the impact on the use of scales was minimal. The structure and loadings were invariant across experimental condition. The pro scale was associated with a lower probability of having engaged in unprotected sexual behavior for sexually active subjects, and this association remained significant while controlling for demographic variables. The con scale did not show a significant association with engagement in unprotected sexual behaviors. Limitations and directions for future research were also discussed.^

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Microscopic and electron probe examination of some manganese nodules show that they consist of segregations of manganese-iron oxides in an interstitial material almost free of manganese but rich in iron and silicates. The segregations are widely spaced in the volcanic cores of the nodules but become more abundant towards their outer crusts where they form the centres of linked polygons of interstitial materials. Most of the minor elements are concentrated in the segregations compared to the interstitial materials. It is suggested that the structures observed result partly from solution and reprecipitation of elements in the original volcanic cores of the nodules and partly from the replacement and coating of these cores by manganese-iron oxides precipitated from sea water.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Flow transverse bedforms (ripples and dunes) are ubiquitous in rivers and coastal seas. Local hydrodynamics and transport conditions depend on the size and geometry of these bedforms, as they constitute roughness elements at the bed. Bedform influence on flow energy must be considered for the understanding of flow dynamics, and in the development and application of numerical models. Common estimations or predictors of form roughness (friction factors) are based mostly on data of steep bedforms (with angle-of-repose lee slopes), and described by highly simplified bedform dimensions (heights and lengths). However, natural bedforms often are not steep, and differ in form and hydraulic effect relative to idealised bedforms. Based on systematic numerical model experiments, this study shows how the hydraulic effect of bedforms depends on the flow structure behind bedforms, which is determined by the bedform lee side angle, aspect ratio and relative height. Simulations reveal that flow separation behind bedform crests and, thus, a hydraulic effect is induced at lee side angles steeper than 11 to 18° depending on relative height, and that a fully developed flow separation zone exists only over bedforms with a lee side angle steeper than 24°. Furthermore, the hydraulic effect of bedforms with varying lee side angle is evaluated and a reduction function to common friction factors is proposed. A function is also developed for the Nikuradse roughness (k s), and a new equation is proposed which directly relates k s to bedform relative height, aspect ratio and lee side angle.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Large asymmetric bed forms commonly develop in rivers. The turbulence associated with flow separation that develops over their steep lee side is responsible for the form shear stress which can represent a substantial part of total shear stress in rivers. This paper uses the Delft3D modeling system to investigate the effects of bed form geometry and forcing conditions on flow separation length and associated turbulence, and bed form shear stress over angle-of-repose (30 lee side angle) bed forms. The model was validated with lab measurements that showed sufficient agreement to be used for a systematic analysis. The influence of flow velocity, bed roughness, relative height (bed form height/water depth), and aspect ratio (bed form height/length) on the variations of the normalized length of the flow separation zone, the extent of the wake region (where the turbulent kinetic energy (TKE) was more than 70% of the maximum TKE), the average TKE within the wake region and the form shear stress were investigated. Form shear stress was found not to scale with the size of the flow separation zone but to be related to the product of the normalized extent of the wake region (extent of the wake region/extent of water body above the bed form) and the average TKE within the wake region. The results add to understanding of the hydrodynamics of bed forms and may be used for the development of better parameterizations of smallscale processes for application in large-scale studies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Major element geochemical composition was established for 59 tephra horizons from Ocean Drilling Program Sites 1150 and 1151, located in the Japan forearc. These data, encompassing typically between 15 and 30 individual shard analyses per tephra horizon, were used to investigate the degree to which sediment reworking, postdepositional geochemical alteration, and geochemical uniqueness of individual eruptives facilitate or impede the potential for establishing a tephrostratigraphical framework for the Japan Trench, as well as usage of the tephra record to document arc evolution. Evidence was found that hydration (termed phase 1 alteration) of glass shards increases with age in the Pliocene-Pleistocene, but there is no indication that element leaching (phase 2 alteration) has occurred. Post- or syn-depositional differences in preservational style are shown to have no significant bearing on tephrogeochemical homogeneity and suitability for tephrostratigraphical analysis. Overall, therefore, the volcaniclastic record is suitable for investigating medium- to long-term changes in arc geochemistry and, provided consideration is given to the potential for nonunique geochemical signatures, is suitable for erecting tephrochronological frameworks. A limited number of Pleistocene tephra correlations are suggested in furtherance of this framework goal.