State promotion of local public goods: The case of public libraries, 1880-1929

The public library movement of the late nineteenth and early twentieth centuries led to a significant expansion of library services across the United States. We study the impact of state-level institutional development on the creation of local public goods. State library commissions were modestly funded state entities charged with helping localities establish libraries. State library associations were voluntary organizations with a similar mission, having as members the librarians of existing public libraries. Library-enabling legislation clarified the legality and taxation possibilities for local government entities such as towns, municipalities and counties to support libraries. Employing panel data drawn from a series of detailed reports on public libraries conducted by the U.S. Bureau of Education, we use a difference-in-differences methodology to identify the impact of commissions, associations, and enabling legislation on library development in matched pairs of counties that straddle state borders. Our results suggest that state-level institutions and legislation had a statistically and economically significant effect on public library development. The finding has implications for future interpretations of the history of the United States as a “nation of joiners”; local civic engagement and associational life was importantly influenced by larger scale civic and political action. JEL classifications: H40, H75, N31, N32, N41, N4

Public libraries and political participation, 1870-1940

The public library movement of the late 19th and early 20th centuries fostered a rapid increase in the number and quality of public libraries in cities and towns across the United States. One important argument for libraries was that they would enhance American democracy by promoting virtues of citizenship and enabling access to information. This paper examines how voter turnout was affected, in the short-term, by the establishment of public libraries, using a county-by-election year panel. Our empirical strategy exploits the founding dates of public libraries as discrete events that should have influenced subsequent voting behavior. Over the wide range of specifications considered, the vast majority of regression results suggest that libraries had no significant short term impact on voter turnout. We discuss potential reasons for this finding, and compare it with recent work finding a positive impact of newspapers on political participation. JEL classifications: H40, H75, N31, N32, N41, N4

The Decline and Rise of Interstate Migration in the United States: Evidence from the IPUMS, 1850-1990

We examine evidence on trends in interstate migration over the past 150 years, using data from the Integrated Public Use Microdata Series of the U.S. Census (IPUMS). Two measures of migration are calculated. The first considers an individual to have moved if she is residing in a state different from her state of birth. The second considers a family to have moved if it is residing in a state different from the state of birth of one of its young children. The latter measure allows us estimate the timing of moves more accurately. Our results suggest that overall migration propensities have followed a U-shaped trend since 1850, falling until around 1900 and then rising until around 1970. We examine variation in the propensity to make an interstate move by age, sex, race, nativity, region of origin, family structure, and education. Counterfactuals based on probit estimates of the propensity to migrate suggest that the rise in migration of families since 1900 is largely attributable to increased educational attainment. The decline of interstate migration in the late nineteenth century remains to be explained.

The GSFC Mark-2 three band hand-held radiometer

A self-contained, portable, hand-radiometer designed for field usage was constructed and tested. The device, consisting of a hand-held probe containing three sensors and a strap supported electronic module, weighs 4 1/2 kilograms. It is powered by flashlight and transistor radio batteries, utilizes two silicon and one lead sulfide detectors, has three liquid crystal displays, sample and hold radiometric sampling, and its spectral configuration corresponds to LANDSAT-D's thematic mapper bands. The device was designed to support thematic mapper ground-truth data collection efforts and to facilitate 'in situ' ground-based remote sensing studies of natural materials. Prototype instruments were extensively tested under laboratory and field conditions with excellent results

From Quasi-Private to Quasi-Public: The Development of Local Libraries in the United States, 1870-1930

The period 1870-1930 witnessed the emergence of the local public library as a widespread and enduring American institution. During these years, access to free community-based library services spread to a much larger share of the U.S. population, while the institutional structure of local libraries underwent a transition from largely quasi-private, voluntary associations to the tax-supported public institutions familiar today. In this paper we describe this transition, and document the expansion of public libraries and library services in the United States over these years, using data drawn from library surveys conducted by the federal Bureau of Education. We then review some causal accounts for that expansion. Exploiting cross-state and temporal variation in the data, we estimate cross-section and panel regressions to assess plausible demand and supply factors affecting the pace of library development. We consider a number of the social and economic variables that have been found to correlate with the development of secondary educational institutions, which expanded during roughly the same historical period: these include, when available, income or wealth, urbanization, ethnic composition, and in some specifications average levels of education and literacy. We also examine the effect of legal and political factors that were specific to public libraries, such as state library commissions and associations

The Upper Atmosphere of HD17156b

HD17156b is a newly-found transiting extrasolar giant planet (EGP) that orbits its G-type host star in a highly eccentric orbit (e~0.67) with an orbital semi-major axis of 0.16 AU. Its period, 21.2 Earth days, is the longest among the known transiting planets. The atmosphere of the planet undergoes a 27-fold variation in stellar irradiation during each orbit, making it an interesting subject for atmospheric modelling. We have used a three-dimensional model of the upper atmosphere and ionosphere for extrasolar gas giants in order to simulate the progress of HD17156b along its eccentric orbit. Here we present the results of these simulations and discuss the stability, circulation, and composition in its upper atmosphere. Contrary to the well-known transiting planet HD209458b, we find that the atmosphere of HD17156b is unlikely to escape hydrodynamically at any point along the orbit, even if the upper atmosphere is almost entirely composed of atomic hydrogen and H+, and infrared cooling by H3+ ions is negligible. The nature of the upper atmosphere is sensitive to to the composition of the thermosphere, and in particular to the mixing ratio of H2, as the availability of H2 regulates radiative cooling. In light of different simulations we make specific predictions about the thermosphere-ionosphere system of HD17156b that can potentially be verified by observations.Comment: 31 pages, 42 eps figure

Ultrafast depolarization of the fluorescence in a conjugated polymer

The effect of the extent of pi electron conjugation on the primary photophysics in semiconducting polymers is reported. A rapid depolarization of photoluminescence and transient absorption, which indicates a reorientation of the transition dipole moment by similar to 30 degrees on a sub-100 fs time scale, is observed in the fully conjugated polymer poly[2-(2'-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene] (MEH-PPV). In contrast, partially conjugated polymers exhibit a much slower depolarization. The results reveal rapid changes of exciton delocalization in the fully conjugated MEH-PPV driven by structural relaxation

Gut microbiota-derived propionate reduces cancer cell proliferation in the liver

Peer reviewedPublisher PD

Placental syncytiotrophoblast constitutes a major barrier to vertical transmission of Listeria monocytogenes.

Listeria monocytogenes is an important cause of maternal-fetal infections and serves as a model organism to study these important but poorly understood events. L. monocytogenes can infect non-phagocytic cells by two means: direct invasion and cell-to-cell spread. The relative contribution of each method to placental infection is controversial, as is the anatomical site of invasion. Here, we report for the first time the use of first trimester placental organ cultures to quantitatively analyze L. monocytogenes infection of the human placenta. Contrary to previous reports, we found that the syncytiotrophoblast, which constitutes most of the placental surface and is bathed in maternal blood, was highly resistant to L. monocytogenes infection by either internalin-mediated invasion or cell-to-cell spread. Instead, extravillous cytotrophoblasts-which anchor the placenta in the decidua (uterine lining) and abundantly express E-cadherin-served as the primary portal of entry for L. monocytogenes from both extracellular and intracellular compartments. Subsequent bacterial dissemination to the villous stroma, where fetal capillaries are found, was hampered by further cellular and histological barriers. Our study suggests the placenta has evolved multiple mechanisms to resist pathogen infection, especially from maternal blood. These findings provide a novel explanation why almost all placental pathogens have intracellular life cycles: they may need maternal cells to reach the decidua and infect the placenta