Probing The Lower Mass Limit For Supernova Progenitors And The High-Mass End Of The Initial-Final Mass Relation From White Dwarfs In The Open Cluster M35 (NGC 2168)

We present a photometric and spectroscopic study of the white dwarf (WD) population of the populous, intermediate-age open cluster M35 (NGC 2168); this study expands upon our previous study of the WDs in this cluster. We spectroscopically confirm 14 WDs in the field of the cluster: 12 DAs, 1 hot DQ, and 1 db star. For each DA, we determine the WD mass and cooling age, from which we derive each star's progenitor mass. These data are then added to the empirical initial-final mass relation (IFMR), where the M35 WDs contribute significantly to the high-mass end of the relation. The resulting points are consistent with previously published linear fits to the IFMR, modulo moderate systematics introduced by the uncertainty in the star cluster age. Based on this cluster alone, the observational lower limit on the maximum mass of WD progenitors is found to be similar to 5.1M(circle dot) - 5.2M(circle dot) at the 95% confidence level; including data from other young open clusters raises this limit to as high as 7.1M(circle dot), depending on the cluster membership of three massive WDs and the core composition of the most massive WDs. We find that the apparent distance modulus and extinction derived solely from the cluster WDs ((m-M)(V) = 10.45 +/- 0.08 and E(B-V) = 0.185 +/- 0.010, respectively) is fully consistent with that derived from main-sequence fitting techniques. Four M35 WDs may be massive enough to have oxygen - neon cores; the assumed core composition does not significantly affect the empirical IFMR. Finally, the two non-DA WDs in M35 are photometrically consistent with cluster membership; further analysis is required to determine their memberships.NSF AST-0397492, AST-0602288Astronom

Social Position and Distributive Justice: Experimental Evidence

Using a simple, double-blind dictator experiment, we examine the extent to which subjects\u27 choices of distributive shares are influenced by unearned social position. We measure social position by the initial distributive shares (resources) and the subjects\u27 ability to determine the final distributive shares (power). We find that subjects\u27 decisions are consistent with Rawls\u27 (1971) hypothesis that individuals expect a greater share when in a position with more power and initial resources. Finally, we test if subjects\u27 choices under a laboratory veil of ignorance are consistent with Rawls\u27 concept of distributive justice. Veiled individuals exhibit preferences that are less risk-averse and have greater variance than Rawls hypothesized. [excerpt

Characterization Approaches to Place Invariant Sites on SI-Traceable Scales

The effort to understand the Earth's climate system requires a complete integration of remote sensing imager data across time and multiple countries. Such an integration necessarily requires ensuring inter-consistency between multiple sensors to create the data sets needed to understand the climate system. Past efforts at inter-consistency have forced agreement between two sensors using sources that are viewed by both sensors at nearly the same time, and thus tend to be near polar regions over snow and ice. The current work describes a method that would provide an absolute radiometric calibration of a sensor rather than an inter-consistency of a sensor relative to another. The approach also relies on defensible error budgets that eventually provides a cross comparison of sensors without systematic errors. The basis of the technique is a model-based, SI-traceable prediction of at-sensor radiance over selected sites. The predicted radiance would be valid for arbitrary view and illumination angles and for any date of interest that is dominated by clear-sky conditions. The effort effectively works to characterize the sites as sources with known top-of-atmosphere radiance allowing accurate intercomparison of sensor data that without the need for coincident views. Data from the Advanced Spaceborne Thermal Emission and Reflection and Radiometer (ASTER), Enhanced Thematic Mapper Plus (ETM+), and Moderate Resolution Imaging Spectroradiometer (MODIS) are used to demonstrate the difficulties of cross calibration as applied to current sensors. Special attention is given to the differences caused in the cross-comparison of sensors in radiance space as opposed to reflectance space. The radiance comparisons lead to significant differences created by the specific solar model used for each sensor. The paper also proposes methods to mitigate the largest error sources in future systems. The results from these historical intercomparisons provide the basis for a set of recommendations to ensure future SI-traceable cross calibration using future missions such as CLARREO and TRUTHS. The paper describes a proposed approach that relies on model-based, SI-traceable predictions of at-sensor radiance over selected sites. The predicted radiance would be valid for arbitrary view and illumination angles and for any date of interest that is dominated by clear-sky conditions. The basis of the method is highly accurate measurements of at-sensor radiance of sufficient quality to understand the spectral and BRDF characteristics of the site and sufficient historical data to develop an understanding of temporal effects from changing surface and atmospheric conditions

Playing the Game: Trout Unlimited’s engagement with the U.S. Federal Energy Regulatory Commission (FERC) in advocating dam removal on the Clyde River, VT and the Kennebec River, ME

This paper examines interactions between the non-profit interest group Trout Unlimited (TU) and the Federal Energy Regulatory Commission (FERC) during debates over dam removal. It uses one case study on the Clyde River in Vermont and one on the Kennebec River in Maine, delving into the tactics used by TU and to show how the group’s activities contributed to FERC recommendations for dam removal in both cases. Bureaucratic Behavior Theory is used as the framework to analyze agency rules, citizen participation, and agency official’s beliefs. Kingdon’s Policy Streams framework supports ancillary investigation into the transformation of private economic environmental groups to professionally-managed, science-based groups exemplified by TU. The dam removal scenario introduces a new formula for groups that act as policy entrepreneurs by assembling knowledge communities and actively seeking to apply their solutions. Other interest groups may be able to use this formula to position themselves for success when engaging federal agencies.No embarg

Multi-Period Rent-Seeking Contests with Carryover: Theory and Experimental Evidence

The majority of theoretical and experimental research stemming from Tullock’s (1980) model of rent-seeking considers static, single-period contests. This paper contributes to a growing body of research on multi-period rent-seeking contests by developing and experimentally testing a model in which a player’s effort affects the probability of winning a contest in both the current and future periods. Theory predicts that rent-seeking effort will be shifted forward from later to earlier periods, with no change in overall rent-seeking expenditures relative to the static contest. Experimental results indicate a significant shift forward when “carryover” is present and that the amount shifted is directly related to the carryover rate. Finally, although experimental expenditures are greater than the equilibrium predictions, overall rent-seeking effort in the carryover contests is lower than in similar static contests.

Endowment Effects and Contribution Strategies in Public Good Experiments

We investigate behavior in a laboratory public good experiment with unique endowment schemes that allow a wider range of contribution strategies than in standard voluntary contribution mechanism (VCM) experiments. A baseline treatment follows a standard VCM design (subjects receive 10 tokens in each of 10 rounds that may be allocated between a private account and a group account). In a new carry-over treatment, any tokens not allocated to the group account in the current period are made available for contributions in future periods. Under full endowment, subjects receive 100 tokens in round one (rather than 10 tokens per round for each of 10 rounds). In the pledge treatment, subjects’ allocation decisions for an initial endowment of 100 tokens may be changed in any round and are binding only for the final round. We find that the size of the effective endowment and whether contributions are binding significantly impact subject decision making. Deviations from the free riding outcome are greater when subjects have a larger portion of their total endowment earlier in the experiment, and subjects contribute less when their contribution decisions are bindin

Institutions and Information in Multiple-Offer Multilateral Bargaining Games: Theory and Experimental Evidence

No abstract available