Taxation and stability in cooperative games

Cooperative games are a useful framework for modeling multi-agent behavior in environments where agents must collaborate in order to complete tasks. Having jointly completed a task and generated revenue, agents need to agree on some reasonable method of sharing their profits. One particularly appealing family of payoff divisions is the core, which consists of all coalitionally rational (or, stable) payoff divisions. Unfortunately, it is often the case that the core of a game is empty, i.e. there is no payoff scheme guaranteeing each group of agents a total payoff higher than what they can get on their own. As stability is a highly attractive property, there have been various methods of achieving it proposed in the literature. One natural way of stabilizing a game is via taxation, i.e. reducing the value of some coalitions in order to decrease their bargaining power. Existing taxation methods include the ε-core, the least-core and several others. However, taxing coalitions is in general undesirable: one would not wish to overly tamper with a given coalitional game, or overly tax the agents. Thus, in this work we study minimal taxation policies, i.e. those minimizing the amount of tax required in order to stabilize a given game. We show that games that minimize the total tax are to some extent a linear approximation of the original games, and explore their properties. We demonstrate connections between the minimal tax and the cost of stability, and characterize the types of games for which it is possible to obtain a tax-minimizing policy using variants of notion of the ε-core, as well as those for which it is possible to do so using reliability extensions. Copyright © 2013, International Foundation for Autonomous Agents and Multiagent Systems (www.ifaamas.org). All rights reserved

Axion hot dark matter bounds after Planck

We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an upper limit m_a < 0.67 eV at 95% C.L. after marginalising over the unknown neutrino masses, using CMB temperature and polarisation data from Planck and WMAP respectively, the halo matter power spectrum extracted from SDSS-DR7, and the local Hubble expansion rate H_0 released by the Carnegie Hubble Program based on a recalibration of the Hubble Space Telescope Key Project sample. Leaving out the local H_0 measurement relaxes the limit somewhat to 0.86 eV, while Planck+WMAP alone constrain the axion mass to 1.01 eV, the first time an upper limit on m_a has been obtained from CMB data alone. Our axion limit is therefore not very sensitive to the tension between the Planck-inferred H_0 and the locally measured value. This is in contrast with the upper limit on the neutrino mass sum, which we find here to range from 0.27 eV at 95% C.L. combining all of the aforementioned observations, to 0.84 eV from CMB data alone.Comment: 20 pages, 8 figures, matches version published in JCAP 1310 (2013) 02

Evaluation of the Impact of the Mother and Infant Health Project in Ukraine

This paper exploits a unique opportunity to evaluate the impact of the quality change in the labor and delivery services on maternal and infant health. Since basic medical care has been universally available in Ukraine, implementation of the Mother and Infant Health Project allows addressing quality rather than quantity effect of medical care. Employing program evaluation methods we find that the administrative units participating in the Project have exhibited greater improvements in both maternal and infant health compared to the control rayons. Among the infant health outcomes, the MIHP impact is most pronounced for infant mortality resulted from deviations in perinatal period and respiratory system failures. As for the maternal health, the MIHP is the most effective at addressing anemia, blood circulation, and urinary-genital system complications, as well as late toxicosis. The analysis suggests that the effects are due to early attendance of antenatal clinics, lower share of C-sections, and greater share of normal deliveries, and these effects are causal. Preliminary cost-effectiveness analysis shows enormous benefit per dollar spent on the project: the cost to benefit ratio is one to 122 taking into account both maternal and infant lives saved as well as cost savings due to changes in labor and delivery practices.maternal health, maternal mortality, infant health, infant mortality, prenatal care

An Improved Separation of Regular Resolution from Pool Resolution and Clause Learning

We prove that the graph tautology principles of Alekhnovich, Johannsen, Pitassi and Urquhart have polynomial size pool resolution refutations that use only input lemmas as learned clauses and without degenerate resolution inferences. We also prove that these graph tautology principles can be refuted by polynomial size DPLL proofs with clause learning, even when restricted to greedy, unit-propagating DPLL search

In vivo therapeutic efficacy of frog skin-derived peptides against Pseudomonas aeruginosa-induced pulmonary infection

Pseudomonas aeruginosa is an opportunistic and frequently drug-resistant pulmonary pathogen especially in cystic fibrosis sufferers. Recently, the frog skin-derived antimicrobial peptide (AMP) Esc(1-21) and its diastereomer Esc(1-21)-1c were found to possess potent in vitro antipseudomonal activity. Here, they were first shown to preserve the barrier integrity of airway epithelial cells better than the human AMP LL-37. Furthermore, Esc(1-21)-1c was more efficacious than Esc(1-21) and LL-37 in protecting host from pulmonary bacterial infection after a single intra-tracheal instillation at a very low dosage of 0.1 mg/kg. The protection was evidenced by 2-log reduction of lung bacterial burden and was accompanied by less leukocytes recruitment and attenuated inflammatory response. In addition, the diastereomer was more efficient in reducing the systemic dissemination of bacterial cells. Importantly, in contrast to what reported for other AMPs, the peptide was administered at 2 hours after bacterial challenge to better reflect the real life infectious conditions. To the best of our knowledge, this is also the first study investigating the effect of AMPs on airway-epithelia associated genes upon administration to infected lungs. Overall, our data highly support advanced preclinical studies for the development of Esc(1-21)-1c as an efficacious therapeutic alternative against pulmonary P. aeruginosa infection

Resource survey of Looe Key National Marine Sanctuary, 1983

Forward: Looe Key National Marine Sanctuary (LKNMS) was designated in 1981 to protect and promote the study, teaching, and wise use of the resources of Looe Key Sanctuary (Plate A). In order to wisely manage this valuable resource, a quantitative resource inventory was funded by the Sanctuary Programs Division (SPD), Office of Ocean and Coastal Resource Management, National Oceanic and Atmospheric Administration (NOAA) in cooperation with the Southeast Fisheries Center, National Marine Fisheries Service, NOAA; the Cooperative Institute for Marine and Atmospheric Studies (CIMAS), University of Miami; the Fisher Island Laboratory, United States Geological Survey; and the St. Petersburg Laboratory, State of Florida Department of Natural Resources. This report is the result of this cooperative effort. The objective of this study was to quantitatively inventory selected resources of LKNMS in order to allow future monitoring of changes in the Sanctuary as a result of human or natural processes. This study, referred to as Phase I, gives a brief summary of past and present uses of the Sanctuary (Chapter 2); and describes general habitat types (Chapter 3), geology and sediment distribution (Chapter 4), coral abundance and distribution (Chapter 5), the growth history of the coral Montastraea annularis (Chapter 6), reef fish abundance and distribution (Chapter 7), and status of selected resources (Chapter 8). An interpretation of the results of the survey are provided for management consideration (Chapter 9). The results are expected to provide fundamental information for applied management, natural history interpretation, and scientific research. Numerous photographs and illustrations were used to supplement the report to make the material presented easier to comprehend (Plate B). We anticipate the information provided will be used by managers, naturalists, and the general public in addition to scientists. Unless otherwise indicated, all photographs were taken at Looe Key Reef by Dr. James A. Bohnsack. The top photograph in Plate 7.8 was taken by Michael C. Schmale. Illustrations were done by Jack Javech, NMFS. Field work was initiated in May 1983 and completed for the most part by October 1983 thanks to the cooperation of numerous people and organizations. In addition to the participating agencies and organizations we thank the Newfound Harbor Marine Institute and the Division of Parks and Recreation, State of Florida Department of Natural Resources for their logistical support. Special thanks goes to Billy Causey, the Sanctuary Manager, for his help, information, and comments. We thank in alphabetical order: Scott Bannerot, Margie Bastian, Bill Becker, Barbara Bohnsack, Grant Beardsley, John Halas, Raymond Hixon, Irene Hooper, Eric Lindblad, and Mike Schmale. We dedicate this effort to the memory of Ray Hixon who participated in the study and who loved Looe Key. (PDF contains 43 pages