L'étude des phénomènes identitaires a connu des avancées importantes depuis le début des années 1980, notamment à cause d'un regain d'intérêt pour la question du nationalisme. Malgré ces avancées, certaines difficultés théoriques persistent quand vient le temps d'utiliser les concepts de « nation », de « race » et « d'ethnie » à des fins analytiques. La place qui doit être accordée à ces concepts ne fait pas consensus. Ce mémoire propose de convoquer des éléments de la théorie des champs pour contourner ce problème et augmenter la portée analytique de ces concepts, en particulier de celui de « nation ». En considérant les « nations » les « races » et les « ethnies » comme des catégories de la pratique, il devient possible d'envisager le nationalisme, le racisme et l'influence de ces catégories sur les rapports sociaux en s'affranchissant des impératifs propres au débat politique. Cela permet de mieux distinguer les phénomènes identitaires entre eux, de mieux cerner leurs rapports mutuels et de favoriser un rapprochement entre l'analyse des rapports sociaux et celle des « identités ». ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Nations, Nationalismes, Théorie de l'identité, Théorie des champs, Rapports sociaux, Ethnicité, Racisme.

<p>Older women in the U.S. face greater risks of economic insecurity in comparison with other age groups and with men their own age. Although these risks have been documented in prior research, few studies investigate the life course mechanisms underlying women's retirement insecurity. This dissertation seeks to fill this gap by using a life course perspective and the theory of cumulative disadvantage to examine how women's earlier work and family experiences shape subsequent economic resources in retirement. The three major types of retirement resources in the U.S. - Social Security benefits, occupational pensions, and private retirement wealth - are considered. Analyses use a variety of modeling techniques and panel data from the Health and Retirement Study linked to restricted access Social Security Administration files. In addition, this dissertation specifically investigates retirement insecurity across birth cohorts of older women.</p> <p>The first substantive chapter examines how Social Security benefit eligibility type is influenced by four major life course predictors: marital continuity, family timing, employment commitment, and cohort change. Social Security benefit type is an important indicator of retirement security for women because, despite nearly universal program coverage, benefit type is associated with differential economic security in retirement for women. Multinomial logit models demonstrate the importance of women's own paid employment histories for later benefit type. Receiving own worker Social Security benefits or being dually eligible for Social Security are more likely outcomes with increased employment experience. The second empirical chapter uses discrete-time even history models to examine the timing of women's access to occupation pension income. The timing of pension income receipt is relevant for women's retirement security because delayed access indicates a missing source of economic resources. Results reveal significant cohort differences in the timing of first pension receipt as well as the important roles of marital continuity and family timing for older women's access to occupational pension income. The final empirical chapter employs age-based growth models to examine differential trajectories of private retirement savings in early retirement (ages 51-65) across U.S. birth cohorts of women. This analysis examines both initial retirement wealth and wealth accumulation over time to understand how life course processes advantage some older women, but contribute to ongoing disadvantage for others as part of this third, major source of retirement security. Results from growth models reveal variation across birth cohorts as well as the negative effects of divorce for initial wealth holdings and growth in retirement wealth. Overall, this dissertation illustrates the importance of women's work and family experiences across the life course for the cumulative disadvantages they face in retirement. Moreover, each type of major retirement resource interacts with different aspects of women's prior work and family roles to produce economic outcomes in retirement.</p> / Dissertation

<p>This thesis examines causal inference related topics involving intermediate variables, and uses Bayesian methodologies to advance analysis capabilities in these areas. First, joint modeling of outcome variables with intermediate variables is considered in the context of birthweight and censored gestational age analyses. The proposed methodology provides improved inference capabilities for birthweight and gestational age, avoids post-treatment selection bias problems associated with conditional on gestational age analyses, and appropriately assesses the uncertainty associated with censored gestational age. Second, principal stratification methodology for settings where causal inference analysis requires appropriate adjustment of intermediate variables is extended to observational settings with binary treatments and binary intermediate variables. This is done by uncovering the structural pathways of unmeasured confounding affecting principal stratification analysis and directly incorporating them into a model based sensitivity analysis methodology. Demonstration focuses on a study of the efficacy of influenza vaccination in elderly populations. Third, flexibility, interpretability, and capability of principal stratification analyses for continuous intermediate variables are improved by replacing the current fully parametric methodologies with semiparametric Bayesian alternatives. This presentation is one of the first uses of nonparametric techniques in causal inference analysis,</p><p>and opens a connection between these two fields. Demonstration focuses on two studies, one involving a cholesterol reduction drug, and one examine the effect of physical activity on cardiovascular disease as it relates to body mass index.</p> / Dissertation

The United States has seen tremendous growth since it has achieved a population of 300 million. Interestingly, events like this mask the heterogeneity of fertility behavior particularly along racial/ethnic lines. Unfortunately, despite the voluminous literature examining the dynamics and differentials of fertility, extant studies suffer from several limitations including the treatment of racial/ethnic groups as homogenous, the cross-sectionality of their analyses, or their focus on either current or cumulative fertility ultimately underplaying the complexity of fertility behavior. Therefore, this dissertation investigates the fertility behavior of Mexican American and white women paying particular attention to race/ethnicity and social mobility by conducting a quantitative analysis of current and cumulative fertility behavior of women at three different points in their life course. The findings demonstrate the significant effect that socioeconomic characteristics and race have on explaining the higher fertility of Mexican American women in the United States thus, encouraging the adoption of a racial/ethnic stratification framework in studies of fertility.

A combination of in situ sampling and numerical modeling was used to investigate the effects of mesoscale (<50 km) circulation patterns and stratification on the evolution of hypoxia on the Louisiana Shelf. Temperature, salinity, and dissolved oxygen concentrations records reveal the presence of an alongshelf meander, which is manifested vertically and horizontally as a wave-like distribution of the properties in the water column. The observations suggest the meander is a ubiquitous characteristic of the shelf with alongshore spatial scale approximately 50 km and less, which is consistent with the locations of sandy shoals along the coast and the local deformation radius. Twelve numerical experiments using an idealized three-dimensional shelf circulation model were performed to evaluate the relative importance of the variable bottom topography and freshwater forcing on the development, evolution, and scales of the dynamic instabilities. The inclusion of the shoals into the bottom topography showed the development of the dynamic instabilities as the flow passed over the shoals and downstream. Introduction of fresh water onto the shelf resulted in greater salinity differences, and, as a consequence in the formation of the dynamically unstable salinity fronts along the plume edge. The combination of the freshwater forcing and shoaling topography produced competing and complex interactions. Six numerical experiments were analyzed in order to investigate the effect of dynamic instabilities on spatial and temporal patterns of dissolved oxygen concentrations along the shelf. Although a linear relationship between Brunt-Väisälä frequency and dissolved oxygen deficit was expected, a nonlinear loop-like relationship was discovered that reflects the response of biochemical properties to the alongshelf variability of the density field. Comparison of the numerical modeling runs to observations of density and dissolved oxygen concentrations on the Louisiana Shelf reinforces the importance of physical processes such as topographic steering and/or freshwater forcing on the alongshore distribution of physical and biochemical properties. It suggests that the time scales of respiration (~3 days) and buoyancy transfer processes (~5-7 days), associated with the physical processes that are responsible for water column stability and ventilation, are similar to the time scales associated with the benthic respiration rates.

Corpus Christi Bay (TX, USA) is a shallow wind-driven bay which is designated as a National Estuary due to its impact on the economy. But this bay experiences periodic hypoxia (dissolved oxygen <2 mg/l) which threatens aerobic aquatic organisms. Development of the Coastal Margin Observation and Assessment System (CMOAS) through integration of real-time observations with numerical modeling helps to understand the processes causing hypoxia in this energetic bay. CMOAS also serves as a template for the implementation of observational systems in other dynamic ecosystems for characterizing and predicting other episodic events such as harmful algal blooms, accidental oil spills, sediment resuspension events, etc. State-of-the-art sensor technologies are involved in real-time monitoring of hydrodynamic, meteorological and water quality parameters in the bay. Three different platform types used for the installation of sensor systems are: 1) Fixed Robotic, 2) Mobile, and 3) Remote. An automated profiler system, installed on the fixed robotic platform, vertically moves a suite of in-situ sensors within the water column for continuous measurements. An Integrated Data Acquisition, Communication and Control system has been configured on our mobile platform (research vessel) for the synchronized measurements and real-time visualization of hydrodynamic and water quality parameters at greater spatial resolution. In addition, a high frequency (HF) radar system has been installed on remote platforms to generate surface current maps for Corpus Christi (CC) Bay and its offshore area. This data is made available to stakeholders in real-time through the development of cyberinfrastructure which includes establishment of communication network, software development, web services, database development, etc. Real-time availability of measured datasets assists in implementing an integrated sampling scheme for our monitoring systems installed at different platforms. With our integrated system, we were able to capture evidence of an hypoxic event in Summer 2007. Data collected from our monitoring systems are used to drive and validate numerical models developed in this study. The analysis of observational datasets and developed 2-D hydrodynamic model output suggests that a depth-integrated model is not able to capture the water current structure of CC Bay. Also, the development of a threedimensional mechanistic dissolved oxygen model and a particle aggregation transport model (PAT) helps to clarify the critical processes causing hypoxia in the bay. The various numerical models and monitoring systems developed in this study can serve as valuable tools for the understanding and prediction of various episodic events dominant in other dynamic ecosystems.

Shear velocity is a critical variable used in many hydrodynamic and aeolian applications. The Law of the Wall is commonly used to derive shear velocity as the product of the slope of a measured velocity profile and the von Kármán constant, κ = 0.4. However, a number of hydrodynamic experiments show that there is a substantial apparent decrease of κ in sediment-laden flow, which was explained by: 1) The energy loss to support the sediment particle suspension in the fluid and 2) The buoyancy effect due to stratification. The energy loss is associated with sediment concentration and grain size, and the stratification can be characterized by sedimentological flux Richardson number or gradient Richardson number. Since there is an apparent change of κ, the term “apparent von Kármán parameter”, or κa, was adopted from Wright and Parker to replace κ in sediment-laden flow. There has been no study to attempt to detect and to evaluate the variability of κa during aeolian saltation, which is the purpose of this dissertation research. Two “clear air” runs and fifteen “sediment-laden” runs were conducted at the northeast coast of Brazil. Wind profile data were collected by a stack of cup anemometers; “true” shear velocity was estimated by an ultrasonic anemometer; and sediment mass flux profile and grain size were estimated from the sand samples collected in a stack of vertical hose-style traps. With these estimates, κa, sediment concentration and sedimentlogical Richardson numbers were derived. Regression analysis indicates that there is a statistically insignificant relationship between κa and grain size, which may be caused by small range of grain size in the study site. However, there is strong statistical relationship between κa and bulk, volumetric concentration below 25 mm, S25, and between κa and sediment transport rate Q (kg/m/s) as: ka = -2088.4S25 0.3964 and ka = -3.134Q 0.4011 A strong relationship was also found between κa and sedimentological Richardson numbers in the lower saltation layer, which can be well explained by the stratification theory.

Does the specialization and division of labor lead to the unequal distribution of social resources or the power in the highest stratification decide opportunities and incomes? What roles do occupation, incomes, and social status play in this society? The phenomenon of social stratification extending from specialization of labor results in the disputes over equality and inequality. People of different social stratification hold dissimilar social resources, which differentiate the opportunities that they acquire. In order to understand how people perceive the factors of inputs and outputs of social stratification, the experiment of information integration is to understand that the model of information Integration of how different groups and individuals influence the factors of inputs and outputs of social stratification, to investigate the perception of the factors of inputs and outputs of social stratification of different groups, and to increase the related analysis of social stratification in our country. This research takes Information Integration Theory (IIT) as research method to understand the internal process of how people deal with a couple of variables with perception. Integration of function would be the main discourse of Information Integration Theory. Through study, it is found that people usually use simple rules of algebra such as adding, multiplying and averaging to integrate information. The research is designed to induce the factors of inputs of social stratification as education and family background by means of documents; the factors of outcomes of social stratification as reputation of occupation and incomes. Information Integration Theory, IIT is employed to know the subjects¡¦ cognitive algebras and there might be different models of integration for people perceive unfairness very differently. The research result is shown as below:¡G 1 Information integration of the administrative group is the differential-weight averaging model in the category of ¡§education-reputation of occupation¡¨ whereas the working group is the adding model. 2 The information integration of the administrative group and the working group are both the differential-weight averaging model in the category of ¡§education-income¡¨. 3 The information integration of the administrative group and the working group are both the model of addition in the category of ¡§family background-reputation of occupation¡¨. 4 The information integration of the administrative group and the working group are both the differential-weight averaging model in the category of ¡§family background-income¡¨.

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 192-199).

Each state or region within the United States has certain unique and distinct characteristics that cause its economic performance to vary from that of the nation as a whole. Unemployment rates, as summary measures of unutilized manpower resources, frequently serve as a gauge of the general economic situation and social well-being. It is a well documented fact that unemployment is not evenly distributed througout the nation. For example, although 54% of the labor force is concetrated in the northeast and north central regions, they only account for 46% of the unemployment in recent years. This thesis focuses on the measurement and behavior of unemployed in Indiana, with particular attention devoted to contrasting performance by the State's economy with that of the nation as a whole.