The prompt lepton cookbook

We review the calculation of the prompt lepton flux, produced in the atmosphere by the semileptonic decay of charmed particles. We describe side by side the intermediary ingredients used by different authors, which include not only the charm production model, but also other atmospheric particle showering parameters. After evaluating separately the relevance of each single ingredient, we analyze the effect of different combinations over the final result. We highlight the impact of the prompt lepton flux calculation upon high-energy neutrino telescopes.Comment: 21 pages, 10 figures; revised version, accepted for publication in Astroparticle Physic

The Star Cluster Systems of the Magellanic Clouds

The characteristics of the cluster systems of the Magellanic Clouds, as inferred from integrated properties, are compared with those from individual cluster studies and from the field population. The agreement is generally satisfactory though in the case of the LMC, the lack of clusters older than ~3 Gyr is not reflected in the field population. The possible origin(s) for this cluster ``age-gap'' are discussed. The SMC cluster age-metallicity relation is also presented and discussed.Comment: 11 pages, 4 figures. To appear in the Proceedings of IAU Symposium 207, "Extragalactic Star Clusters", eds E. Grebel, D. Geisler and D. Minnit

Beliefs and actions in the trust game: creating instrumental variables to estimate the causal effect

In many economic contexts, an elusive variable of interest is the agent's expectation about relevant events, e.g. about other agents' behavior. Recent experimental studies as well as surveys have asked participants to state their beliefs explicitly, but little is known about the causal relation between beliefs and other behavioral variables. This paper discusses the possibility of creating exogenous instrumental variables for belief statements, by shifting the probabilities of the relevant events. We conduct trust game experiments where the amount sent back by the second player (trustee) is exogenously varied by a random process, in a way that informs only the �first player (trustor) about the realized variation. The procedure allows detecting causal links from beliefs to actions under plausible assumptions. The IV estimates indicate a signi�ficant causal effect, comparable to the connection between beliefs and actions that is suggested by OLS analyses