Who Benefits Whom in Daily Newspaper Markets?

Markets are generally thought to avoid problems, such as tyranny of the majority, that arise when allocation is accomplished through collective processes. Yet, with fixed costs, differentiated product markets deliver only products desired by substantial constituencies. When consumers share similar preferences, then additional consumers will bring forth additional products or improve the attributes or position of existing products and the consumers confer positive pecuniary preference externalities' on each other. However, if distinct groups of consumers have substantially different preferences, the groups can hurt each other through product markets. We document the pattern of preference externalities among black and white consumers of daily newspapers in the US. We find that, in their capacity as newspaper consumers, members of each group benefits themselves and either harm, or fail to benefit, each other through the product market. We document that product positioning provides the mechanism underlying our results. While Friedman (1962) argues that the use of political channels tends to strain the social cohesion essential for a stable society,' while, by contrast, widespread use of the market reduces the strain on the social fabric by rendering conformity unnecessary,' mounting evidence on media markets suggests otherwise.

Isomerization as a Key Path to Molecular Products in the Gas-Phase Decomposition of Halons

The decomposition of halons remains controversial concerning the branching between radical and molecular products. The latter channel, where it has been found, is presumed to occur via a constrained symmetric multicenter transition state. Isomerization pathways in the gas-phase chemistry of halons have rarely been considered, despite the fact that the iso-halons, which feature a halogen−halogen bond, are widely recognized as important reactive intermediates in condensed phases. In this Letter, detailed calculations and modeling of the unimolecular decomposition of several important halons, including CF2Cl2, CF2Br2, and CHBr3, reveal that isomerization is a key pathway to molecular products. This path is important for both halons and their primary radicals as the barrier to isomerization in these compounds is typically isoenergetic with the threshold for bond fission

Bomb radiocarbon and tag-recapture dating of sandbar shark (Carcharhinus plumbeus)

The sandbar shark (Carcharhinus plumbeus) was the cornerstone species of western North Atlantic and Gulf of Mexico large coastal shark fisheries until 2008 when they were allocated to a research-only fishery. Despite decades of fishing on this species, important life history parameters, such as age and growth, have not been well known. Some validated age and growth information exists for sandbar shark, but more comprehensive life history information is needed. The complementary application of bomb radiocarbon and tag-recapture dating was used in this study to determine valid age-estimation criteria and longevity estimates for this species. These two methods indicated that current age interpretations based on counts of growth bands in vertebrae are accurate to 10 or 12 years. Beyond these years, we could not determine with certainty when such an underestimation of age begins; however, bomb radiocarbon and tag-recapture data indicated that large adult sharks were considerably older than the estimates derived from counts of growth bands. Three adult sandbar sharks were 20 to 26 years old based on bomb radiocarbon results and were a 5- to 11-year increase over the previous age estimates for these sharks. In support of these findings, the tag-recapture data provided results that were consistent with bomb radiocarbon dating and further supported a longevity that exceeds 30 years for this species

Exploring Service Learning in Study Abroad: An Evaluation of The Umbra Institute’s Urban Spaces Course

Over the proceeding decades, service learning programs combining academic study with community service have been growing in popularity at U.S. institutions of higher education. This growth has been equated to service learning’s ability to assist students with achieving personal and academic goals, as well as broader goals of civic engagement for communities. With these programs occurring in an increasingly interconnected world, that is also seeing growth in study abroad participation, it is only natural that students would seek out similar service learning opportunities in their international destinations. Today more than 80% of students enrolled at The Umbra Institute in Perugia, Italy, participate in one or more of its service learning course offerings each semester. Participation in such offerings can lead to deeper understanding of course content, facilitate long lasting personal transformations, increase global awareness and intercultural understanding, and encourage the development of civic awareness and active citizenship. With higher education directing increased attention to assessment of these service learning outcomes this study proposed the following question: In a global world, how can international service learning initiatives be better developed to capture the values and expectations of its stakeholders? To answer this question, The Umbra Institute’s ESUS 310: Urban Spaces: Rebuilding Community in Perugia course was utilized as a case study. In this multidisciplinary study, research examined literature and studies on service learning, international service learning, civic education, global citizenship, and community relationships

One year of monitoring the Vela pulsar using a Phased Array Feed

We have observed the Vela pulsar for one year using a Phased Array Feed (PAF) receiver on the 12-metre antenna of the Parkes Test-Bed Facility. These observations have allowed us to investigate the stability of the PAF beam-weights over time, to demonstrate that pulsars can be timed over long periods using PAF technology and to detect and study the most recent glitch event that occurred on 12 December 2016. The beam-weights are shown to be stable to 1% on time scales on the order of three weeks. We discuss the implications of this for monitoring pulsars using PAFs on single dish telescopes.Comment: 6 pages, 4 figures, 2 tables. Accepted for publication in PAS

Spectroscopic and Computational Studies of Matrix-Isolated iso-CXBr3 (X=F,Cl,Br): Structure, Properties, and Photochemistry of Substituted Iso-Tribromomethanes

Iso-polyhalomethanes are important reactive intermediates in the condensed and gas-phase chemistry of halomethanes. Building upon our recent study of iso-bromoform, in this work the substituted iso-tribromomethanes (iso-CXBr3; X = F, Cl, Br) were characterized by matrix isolation infrared and UV/Vis spectroscopy, supported by ab initio calculations, to further probe the structure, spectroscopy, properties, and photochemistry of these important intermediates. Selected wavelength laser irradiation of CXBr3 samples in an inert rare gas (typically Ar; mixing ratio 1:500) held at ∼5 K yielded iso-CXBr3 (XBrC–Br–Br or Br2C–Br–X). The observed infrared and UV/Vis absorptions are in excellent agreement with computational predictions, and the energies of various stationary points on the CXBr3 Potential Energy Surfaces (PESs) were characterized computationally using DFT, MP2, and CCSD (T) methods in combination with triple-zeta quality basis sets. These calculations show that the isomers are minima on the PESs that lie ∼200 kJ/mol above the global CXBr3 minimum, yet are bound by some 50–70 kJ/mol in the gas-phase with respect to the CXBr2 + Br asymptote. Laser irradiation of the isomers resulted in back photoisomerization to CXBr3, and intrinsic reaction coordinate (IRC) calculations confirmed the existence of a first order saddle point connecting the two isomers. Calculations of important stationary points on the CXBr3 PESs show that in the gas-phase the isomerization barrier lies energetically near the threshold for simple bond fission. The iso-CXBr3 species are significantly stabilized in the condensed phase, due to the high degree of ion-pair character, as revealed by Natural Resonance Theory analysis