Migration and the Social Order in Erie County, New York: 1855

Mass transiency remains the most striking and consistent finding to emerge from quantitative studies of Victorian North America. In almost every place where historians have looked at least half, often two thirds, of the adults present at one end of a decade had left ten years later, and rates based on shorter periods reveal a stream of people constantly flowing through nineteenth-century cities. Although 363,000 people lived in Boston in 1880 and 448,000 in 1890, during the decade about one and one-half million people actually had dwelled within the city. When Victorians sought a symbol of progress, they often chose the steam engine; had they wanted a metaphor for their cities, they could have found none more apt than the railroad station. In this paper we confront the question of transiency. Using the New York State Census of 1855 for the entire city of Buffalo and a 10 percent sample of household heads in rural Erie County, we attempt a method of estimating persistence (the proportion of the population remaining in a given place) that is different from that used by most historians. Given the richness of the census, we are able to inquire with great detail into the factors that determined length of residence in a nineteenth-century city and its surrounding countryside

Tracking the Orbital and Super-orbital Periods of SMC X-1

The High Mass X-ray Binary (HMXB) SMC X-1 demonstrates an orbital variation of 3.89 days and a super-orbital variation with an average length of 55 days. As we show here, however, the length of the super-orbital cycle varies by almost a factor of two, even across adjacent cycles. To study both the orbital and super-orbital variation we utilize lightcurves from the Rossi X-ray Timing Explorer All Sky Monitor (RXTE-ASM). We employ the orbital ephemeris from Wojdowski et al. (1998) to obtain the average orbital profile, and we show that this profile exhibits complex modulation during non-eclipse phases. Additionally, a very interesting ``bounceback'' in X-ray count rate is seen during mid-orbital eclipse phases, with a softening of the emission during these periods. This bounceback has not been previously identified in pointed observations. We then define a super-orbital ephemeris (the phase of the super-orbital cycle as a function of date) based on the ASM lightcurve and analyze the trend and distribution of super-orbital cycle lengths. SMC X-1 exhibits a bimodal distribution of these lengths, similar to what has been observed in other systems (e.g., Her X-1), but with more dramatic changes in cycle length. There is some hint, but not conclusive evidence, for a dependence of the super-orbital cycle length upon the underlying orbital period, as has been observed previously for Her X-1 and Cyg X-2. Using our super-orbital ephemeris we are also able to create an average super-orbital profile over the 71 observed cycles, for which we witness overall hardening of the spectrum during low count rate times. We combine the orbital and super-orbital ephemerides to study the correlation between the orbital and super-orbital variations in the system.Comment: 10 pages, using emulateapj style. To be published in the Astrophysical Journa

Advanced Transmission Electron Microscopy Studies of Induced Interactions of Metallic Species with Perovskite Oxide Hosts.

Catalysts are used to remove detrimental gases from the automobile exhaust stream, thus fulfilling an essential need in increasingly environmentally conscious times. The constituent functional materials – some combination of Pt, Pd, and Rh – that compose the catalyst nanoparticles are both rare and expensive, and their performance degrades throughout the catalytic converter lifetime via thermodynamically driven losses of the catalytically active surface area during prolonged exposure to high exhaust temperatures. Conventional oxide powder supports, used to stabilize the catalyst nanoparticles against migration and coarsening, retard coarsening to some degree, but coarsening is nonetheless irreversible on these supports. We report here on microscopy and density functional theory studies of a new class of self-regenerative catalyst/support systems, wherein the catalyst absorbs into a specially selected perovskite oxide support (e.g. LaFeO3 for Pd; CaTiO3 for Pt, Rh) and re-emerges as nanoparticles in a high dispersion. Utilizing ab initio modeling, we find that this behavior is the result of balanced thermodynamic equilibria in which the normal stoichiometric oscillations of the air-fuel mixture alternately favor the catalyst existing as a metallic phase and as a solid solution within the perovskite. Using ex-situ and in-situ transmission electron microscopy experiments on model thin films and powders to study the phenomenology, we find that the movement of catalyst atoms along the self-regenerative dissolution/extrusion route is slower than expected, however, and much of the metal may fail to reach the support surface upon regeneration. The coarsening of catalyst particles on the surface, however, is significantly retarded with respect to its behavior on traditional automotive catalyst supports. Therefore, the morphology of the catalyst support must be carefully engineered for the self-regenerative catalyst to be effective and practical.PhDMaterials Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/98073/1/mbkatz_1.pd

Women and the Paradox of Inequality in the Twentieth Century

Throughout American history, male/female has defined an enduring binary embodied in access to jobs, income, and wealth.Women’s economic history shows how for centuries sex has inscribed a durable inequality into the structure of American labor markets that civil and political rights have moderated but not removed. This economic experience of women reflects the paradox of inequality in America: the coexistence of structural inequality with individual and group mobility.Women, like African Americans, have gained what T.H. Marshall labeled civil and political citizenship. No longer are they legally disenfranchised, and discrimination on account of race and gender is against the law. They have also increased their social citizenship, as represented by access to jobs and education, and women, in particular, benefit from many programs of the welfare state. Yet, they remain unequal. On the whole, they earn less than men, end up in occupational ghettos, bump up against glass ceilings, and find themselves, in relation to men, as poor as ever

Association of urinary uromodulin with kidney function decline and mortality: the health ABC study .

BackgroundUrine uromodulin (uUMOD) is a protein secreted by the kidney tubule. Recent studies have suggested that higher uUMOD may be associated with improved kidney and mortality outcomes.MethodsUsing a case-cohort design, we evaluated the association between baseline uUMOD levels and ≥ 30% estimated glomerular filtration rate (eGFR) decline, incident chronic kidney disease (CKD), rapid kidney function decline, and mortality using standard and modified Cox proportional hazards regression.ResultsThe median value of uUMOD was 25.8 µg/mL, mean age of participants was 74 years, 48% were women, and 39% were black. Persons with higher uUMOD had lower prevalence of diabetes and coronary artery disease (CAD), and had lower systolic blood pressure. Persons with higher uUMOD also had higher eGFR, lower urinary albumin to creatinine ratio (ACR), and lower C-reactive protein (CRP). There was no association of uUMOD with > 30% eGFR decline. In comparison to those in the lowest quartile of uUMOD, those in the highest quartile had a significantly (53%) lower risk of incident CKD (CI 73%, 18%) and a 51% lower risk of rapid kidney function decline (CI 76%, 1%) after multivariable adjustment. Higher uUMOD was associated with lower risk of mortality in demographic adjusted models, but not after multivariable adjustment.ConclusionHigher levels of uUMOD are associated with lower risk of incident CKD and rapid kidney function decline. Additional studies are needed in the general population and in persons with advanced CKD to confirm these findings.


Locating Battery Charging Stations to Facilitate Almost Shortest Paths

We study a facility location problem motivated by requirements pertaining to the distribution of charging stations for electric vehicles: Place a minimum number of battery charging stations at a subset of nodes of a network, so that battery-powered electric vehicles will be able to move between destinations using "t-spanning" routes, of lengths within a factor t > 1 of the length of a shortest path, while having sufficient charging stations along the way. We give constant-factor approximation algorithms for minimizing the number of charging stations, subject to the t-spanning constraint. We study two versions of the problem, one in which the stations are required to support a single ride (to a single destination), and one in which the stations are to support multiple rides through a sequence of destinations, where the destinations are revealed one at a time