The idea of taming the Desert Southwest has captivated the American psyche for hundreds of years. The intoxicating beauty of the wide-open and wild landscape has lured people westward. The lure remains: the U.S. census figures are forecasting that by the year 2030, more than 67 million people will live in the West and that Nevada, Arizona, and Utah will be among the top 5 states in the nation in terms of percentage of population increase. The survival of the Desert Southwest's ecosystem depends greatly on the geographic distribution of this growing population. As the Desert Southwest's population continues to grow, a new urban paradigm is needed. Americans’ 20th century desire to live in nature in order to escape the squalor of the city has been fueled by the automobile and highway systems. These conditions have defined a sprawling and suburbanized pattern of settlement throughout the United States. Charles Waldheim says, “Across many disciplines, and for many centuries, the city and the country have been called upon to define each other through a binary opposition.” Resulting urban models sought to dissolve this opposition between city and nature. Such development had enormous horizontal spatial implications. But, as Edward Glaeser puts it, “it would be a lot better for the planet if their urbanized populations lived in dense cities built around the elevator, rather than in sprawling areas built around the car.” Our horizontal development has had devastating effects on the ecosystems they encroach upon and swallow up. One landscape that is particularly threatened by our outward sprawl is the Sonoran Desert located in the Southwestern United States. The beauty of the wild and unique desert landscape has drawn people and development to it for centuries. The dilemma is that the closer we get, and the more that we try to live within this natural world, the more we destroy it. The suburban development in the region has had a disregard for water usage and resources. Diverted waters from the West’s great rivers, rising temperatures, highways, and loss of habitat have made an arid climate even more unforgiving, put desert flora and fauna in danger of extinction, and endangered the landscape that has been our muse for hundreds of years. This thesis aims to define an intimate relationship between city and nature in the Desert Southwest, but unlike its historical counterparts, proposes that we build up instead of out in order to reduce water and energy use, contain expansion and growth, and begin to repair the land that we have loved to death. / 0 / SPK / specialcollections@tulane.edu

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Ce travail de thèse se concentre sur la dynamique rotationnelle du système couplé graine, noyau externe et manteau. Notre modèle inclut en effet deux couples électromagnétiques directs aux limites du noyau fluide et un couple gravitationnel entre la graine et le manteau. La dynamique rotationnelle est décrite par quatre cisaillements typiques et étudiés dans des simulations numériques convectives de la géodynamo reproduisant les principales caractéristiques du champ magnétique terrestre et de sa variation séculaire. Celle-ci est principalement représentée par la dérive géomagnétique vers l’ouest de taches de flux magnétique à la CMB, concentrée à l’équateur de l’hémisphère Atlantique, et bien documentée pour les quatre derniers siècles. Nous fournissons des contraintes sur la rotation différentielle de la graine en exprimant son lien avec la dérive géomagnétique vers l’ouest. Ceci est réalisé par la formulation et la validation de modèles dynamiques de couples électromagnétiques. Au long terme, le cisaillement global dans le noyau fluide est réparti entre la dérive géomagnétique vers l’ouest et la rotation différentielle de la graine, dans des proportions contrôlées par l’état des couplages. Puisqu’une estimation actuelle de ce cisaillement est proche de la vitesse de la dérive géomagnétique vers l’ouest, nous concluons que la rotation différentielle moyenne de la graine est proche de zéro. En ce qui concerne ses fluctuations, l’intensité du couplage gravitationnel est le paramètre dominant. Cette observation place une limite sur les fluctuations décennales de la rotation différentielle de la graine, qui ne devraient pas excéder quelques centièmes de degré par an / This PhD work focuses on the rotational dynamics of the coupled inner core - outercore - mantle system. The conservation of the angular momentum our coupled Earth model indeed involves two direct electromagnetic torques at the fluid core boundaries and a remote gravitational torque between the inner core and the mantle. The rotational dynamics is described by four typical shears and studied in convective numerical simulations of the geodynamo which are able to reproduce the main characteristics of the geomagnetic field and its secular variation. This secular variation is mainly embodied by the westward drift of magnetic flux patches at the CMB, concentrated on the equator of the Atlantic hemisphere, and is well documented for the last four centuries. We provide constrains on the inner core differential rotation by expressing its link to the geomagnetic westward drift. This is performed through the formulation and the validation of dynamical electromagnetic torque models, which are then introduced in the conservation of the angular momentum of the system. In the long-term state, the global shear in the fluid outer core is distributed between the westward drift and the differential rotation of the inner core, in proportions controlled by the state of couplings. As a present day estimate of this shear is close to the observed westward drift, we conclude there is no differential rotation of the inner core on time-average. In the time-dependent state, we observed that the strength of gravitational coupling is the dominant parameter. This places limit on the decadal fluctuations of the inner core differential rotation, which should not exceed a few hundredths of degree per year

Internal Westward Migration in Germany: 1989-1994 Amy Hubbard Abstract: Contemporary German history has been beleaguered with political, social, and economic upheaval, the consequences of which have led to its modern day composition. One such consequence of Germany's past is the problem of internal westward migration between 1989 and 1994. This analysis looks at the political, social, and economic factors that have led to the increase of internal westward migration from the states of the former German Democratic Republic to the states of the former Federal Republic of Germany. The political, social, and economic developments of the German Democratic Republic combined with the reunification process have led to a feeling of insecurity in the east. People with a strong sense of political, social, or economic insecurity will have a stronger propensity to migration to a stable environment. A variety of governmental programs have been developed to quell the problem but they have been widely unsuccessful. Additionally, there have been a series of negative consequences caused by the existence of internal westward migration on such a scale, such as, the rise of extremist parties in the eastern states of German

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