In Defense of Public Opinion Polling by Kenneth F. Warren

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96742/1/798144.pd

Public evaluations of the presidential nomination process

The evaluation of presidential nomination reforms has been the topic of elite discussion and debate, with little attention paid to popular evaluations. Public attitudes toward a number of reforms to the presidential nomination process were evaluated through survey data collected in 1988. The evaluations included campaign costs, debates, the influence of consultants, and the role of the media. The analysis suggests that there is a relatively high level of popular satisfaction with these dimensions of the current system. Popular concern about the nomination process is focused in two areas—the roles of money and the media. There is a strong suggestion that the movement toward regionalization of the calendar was responsive to partisan concerns in different regions of the country.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45483/1/11109_2005_Article_BF01002141.pd

Preemptive and reactive spending in U.S. House races

This paper examines the spending behavior of candidates for the U.S. House of Representatives. Particular attention is paid to the timing of receipts and expenditures over the complete 2-year election cycle. Incumbents raise and spend large amounts of money very early in the race, and this preemptive spending may have a great impact on the selection of challengers and therefore on electoral outcomes. In addition, a model of reactive spending is tested for the general election period. Incumbents' expenditures are a function of the underlying partisan division in the district, the strength of the challenge, and candidates' feelings of vulnerability. Incumbents are strategic actors who attempt to maximize their chances of reelection. Early in the term, they spend preemptively in an effort to influence the selection of their challengers. Later in the term, they spend in reaction to the strength of their challengers' campaign. The role of money in congressional campaigns is neither simple nor direct. More attention needs to be given to the strategic uses of money in the period leading up to the general election campaign as well as to the dynamics of receipts and expenditures over an entire election cycle.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45496/1/11109_2004_Article_BF00987590.pd

Machine-Readable Data Production by the Federal Government

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68228/2/10.1177_000276427601900402.pd

Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E$^{-2}$ shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E$^{-2}$ be able to explain the observations

Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle