Understanding Economic Biases in Representation: Income, Resources, and Policy Representation in the 110th House

This article explores the extent, and possible causes, of income-based biases in representation of citizens by members of the 110th Congress. The author finds that the preferences of wealthier citizens are modestly but significantly better reflected in the choices of their congressional representatives than are the preferences of poorer citizens. More importantly, the author shows that education, political sophistication, political engagement, ethnicity, and other sociodemographic factors can explain only a small part of this representation gap. Biases in representation across income lines appear to be driven by income alone, or at least not by politically relevant factors correlated with income.

Stress and Strain Adaptation in Load-Dependent Remodeling of the Embryonic Left Ventricle

Altered pressure in the developing left ventricle (LV) results in altered morphology and tissue material properties. Mechanical stress and strain may play a role in the regulating process. This study showed that confocal microscopy, three-dimensional reconstruction, and finite element analysis can provide a detailed model of stress and strain in the trabeculated embryonic heart. The method was used to test the hypothesis that end-diastolic strains are normalized after altered loading of the LV during the stages of trabecular compaction and chamber formation. Stage-29 chick LVs subjected to pressure overload and underload at stage 21 were reconstructed with full trabecular morphology from confocal images and analyzed with finite element techniques. Measured material properties and intraventricular pressures were specified in the models. The results show volume-weighted end-diastolic von Mises stress and strain averaging 50–82% higher in the trabecular tissue than in the compact wall. The volume-weighted-average stresses for the entire LV were 115, 64, and 147Pa in control, underloaded, and overloaded models, while strains were 11, 7, and 4%; thus, neither was normalized in a volume-weighted sense. Localized epicardial strains at mid-longitudinal level were similar among the three groups and to strains measured from high-resolution ultrasound images. Sensitivity analysis showed changes in material properties are more significant than changes in geometry in the overloaded strain adaptation, although resulting stress was similar in both types of adaptation. These results emphasize the importance of appropriate metrics and the role of trabecular tissue in evaluating the evolution of stress and strain in relation to pressure-induced adaptation.

The Cultural Construction Of Posttraumatic Stress Disorder: Sociopolitical Responses To Psychological Trauma In American And Vie

In my thesis, I incorporate both psychological research and personal narratives in order to explain why, in the aftermath of the Vietnam War, the United States officially recognized Post-Traumatic Stress Disorder while the Vietnamese government did not. The absence of Vietnamese studies on the impact of PTSD on veterans, in comparison to the abundance of research collected on American soldiers, is reflective not of a disparity in the actual prevalence of the disorder, but of the influence of political policy on the scope of Vietnamese psychology. Personal narratives from Vietnamese civilians and soldiers thus reveal accounts of trauma otherwise hidden due to the absence of Vietnamese psychological research. Although these two nations conspicuously differed in their respective responses to the prevalence of psychological trauma in war veterans, these responses demonstrated that both the recognition and rejection of PTSD was a result of sociopolitical factors: political ideologies, rather than scientific reasons, dictated whether the postwar trajectory of psychological research focused on fully exploring the impact of PTSD on veteran populations. The association of military defeat with psychological trauma thus fixed attention on certain groups of veterans, including former American and South Vietnamese soldiers, while ignoring the impact of trauma on veterans of the Viet Cong and North Vietnamese Army. The correlation of a soldier¿s ideological background with psychological trauma, rather than exposure to actual traumatic experiences, demonstrates that cultural and sociopolitical factors are far more influential in the construction of PTSD than objective indicators of the disorder¿s prevalence. Culturally-constructed responses to disorders such as PTSD therefore account for the subjective treatment of mental illness. The American and Vietnamese responses to veterans suffering from PTSD both demonstrated that the evidence of mental health problems in an individual does not guarantee an immediate or appropriate diagnosis and treatment regimen. External authorities whose primary aims are not necessarily concerned with the objective treatment of all victims of mental illness subjectively dictate mental health care policy, and therefore risk ignoring or marginalizing the needs of individuals in need of proper treatment.