Party Size and Constituency Representation: Evidence from the 19th-Century U.S. House of Representatives

Research on congressional parties assumes, but has not directly shown, that party size affects individual members' calculations. Drawing on a key case from the nineteenth-century House the secession-driven Republican hegemony of 1861 this article explores the hypothesis that party voting not only declines but also becomes more strongly linked to constituency factors as relative party size increases. The analysis reveals that the jump in party size coincides with (1) a decrease in party voting among individual continuing members, (2) a strengthening association between some constituency factors and party voting, and (3) patterns of decline in individual party voting that are explained in part by constituency measures.

Thin-Film Sparse Boundary Array Design for Passive Acoustic Mapping During Ultrasound Therapy

A new 2-D hydrophone array for ultrasound therapy monitoring is presented, along with a novel algorithm for passive acoustic mapping using a sparse weighted aperture. The array is constructed using existing polyvinylidene fluoride (PVDF) ultrasound sensor technology, and is utilized for its broadband characteristics and its high receive sensitivity. For most 2-D arrays, high-resolution imagery is desired, which requires a large aperture at the cost of a large number of elements. The proposed array's geometry is sparse, with elements only on the boundary of the rectangular aperture. The missing information from the interior is filled in using linear imaging techniques. After receiving acoustic emissions during ultrasound therapy, this algorithm applies an apodization to the sparse aperture to limit side lobes and then reconstructs acoustic activity with high spatiotemporal resolution. Experiments show verification of the theoretical point spread function, and cavitation maps in agar phantoms correspond closely to predicted areas, showing the validity of the array and methodology.

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.

Continuous, Passive Liquid-Liquid Extraction and Emulsion Separation Within Microfluidic and Millifluidic Devices

Liquid-liquid extraction (LLE) is a method used to separate compounds based on their relative activity in two immiscible phases. By significantly reducing the scale of liquid-liquid extraction to the micro- and milli-fluidic levels, this separation process can bemade suitable for low volume, high value materials.

Mental Health and Aging at the 2005 White House Conference on Aging: Two Steps Forward, One Step Back

Success! At the 2005 White House Conference on Aging, three-quarters of the 1,200 national delegates voted to improve “recognition, assessment, and treatment of mental illness and depression among older Americans.” This resulted in mental health being ranked as #8 of the final 50 WHCoA policy resolutions resulting from the conference. Joining this resolution in the “top ten” were two resolutions intimately tied to hopes for addressing the mental health needs of older adults—at #6 “Support Geriatric Education and Training for Health Care Professionals, Paraprofessionals, Health Profession Students and Direct Care Workers,” and #9 “Attain Adequate Numbers of Healthcare Personnel in All Professions Who are Skilled, Culturally Competent, and Specialized in Geriatrics.”