How to Subvert Democracy: Montesinos in Peru

Which of the democratic checks and balances - opposition parties, the judiciary, a free press -is the most critical? Peru has the full set of democratic institutions. In the 1990s, the secret-police chief Vladimiro Montesinos systematically undermined them all with bribes. We quantify the checks using the bribe prices. Montesinos paid television-channel owners about 100 times what he paid judges and politicians. One single television channel’s bribe was four times larger than the total of the opposition politicians’ bribes. By revealed preference, the strongest check on the government’s power was the news media.

Bordos and Boundaries: Sustainable Agriculture in the High Altitude Deserts of Northwest Argentina, AD 850-1532

Bordos were essential for the long-term sustainability of agriculture in the high altitude desert of Antofagasta de la Sierra in Northwest Argentina during the Late (AD 850 – 1480) and Inca Period (AD 1480 – 1532). Bordos were lineal humps of soil that stimulated the pedogenesis of the predominantly sandy soils of the area. Furthermore, they served as boundaries delimiting irrigation and cultivation fields. Therefore, bordos alongside other technologies were an efficient means by which viable farming was possible in an otherwise marginal agricultural zone. Besides explaining the role of bordos in the context of Northwestern Argentine agriculture this article describes the irrigation systems in place at Antofagasta de la Sierra throughout this period and compares it to the present state of affairs. Our results demonstrate that these late Prehispanic bordos and irrigation networks were well set out and organized such that use of water and soil was efficient, proportional and fair. The Inca do not seem to have disrupted these systems or local autonomy over them. In contrast, modern water and soil is characterized by a household-level decentralized management system. This situation leads to serious conflicts over water use allocations, wastage and flawed irrigation resulting in rising ground salinization.Fil: Salminci, Pedro Miguel. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tchilinguirian, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of Cambridge. Faculty of Archaeology and Anthropology; Reino UnidoFil: Lane, Kevin John. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of Cambridge. Faculty of Archaeology and Anthropology; Reino Unid

Feeding and defecation behavior of Triatoma rubida (Uhler, 1894) (Hemiptera: Reduviidae) under laboratory conditions, and its potential role as a vector of chagas disease in Arizona, USA

Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to humans by blood-sucking triatomine insects. This disease is endemic throughout Mexico and Central and South America, but only a few autochthonous cases have been reported in the United States, despite the fact that infected insects readily invade houses and feed on humans. Competent vectors defecate during or shortly after feeding so that infective feces contact the host. We thus studied the feeding and defecation behaviors of the prevalent species in southern Arizona, Triatoma rubida. We found that whereas defecation during feeding was frequent in females (93%), it was very rare in immature stages (3%), and absent in males. Furthermore, more than half of the immature insects that exhibited multiple feeding bouts (62%) defecated during interruptions of feeding, i.e., while likely on or near the host. These results indicate that T. rubida potentially could transmit T. cruzi to humans.Fil: Reisenman, Carolina Esther. University of Arizona; Estados UnidosFil: Gregory, Teresa. University of Arizona; Estados UnidosFil: Guerenstein, Pablo Gustavo. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Hildebrand, John. University of Arizona; Estados Unido

An Agent-Based Simulation of Rental Housing Markets

We simulate a closed rental housing market with search and matching frictions, in which both landlord and tenant agents are imperfectly informed. Homogeneous landlords set rents to maximise revenue, using information on the market to estimate the relationship between posted rent and time-on-the-market (TOM). Tenants, heterogeneous in income, engage in undirected search accepting residences based on their idiosyncratic tastes for housing and a disagreement point derived from information on the distribution of offers. The steady state to which the simulation evolves shows price dispersion, nonzero search times and vacancies.The main results concern the effects of increasing information on either side of the market. When tenants see a greater percentage of the distribution of offers, tenants learn to refuse high rents and so the population rises and tenants' utilities rise as does overall welfare. Conversely, when landlords have less information, their utility can rise as over estimations in best posting rent move the market to higher rents.Real estate; Rental markets; Search; Information; Simulation; Multi-agent systems

How to Subvert Democracy: Montesinos in Peru

Which of the democratic checks and balances - opposition parties, the judiciary, a free press -is the most critical? Peru has the full set of democratic institutions. In the 1990s, the secret-police chief Vladimiro Montesinos systematically undermined them all with bribes. We quantify the checks using the bribe prices. Montesinos paid television-channel owners about 100 times what he paid judges and politicians. One single television channel's bribe was four times larger than the total of the opposition politicians' bribes. By revealed preference, the strongest check on the government's power was the news media

Synapse: automatic behaviour inference and implementation comparison for Erlang

In the open environment of the world wide web, it is natural that there will be multiple providers of services, and that these service provisions — both specifications and implementations — will evolve. This multiplicity gives the user of these services a set of questions about how to choose between different providers, as well as how these choices work in an evolving environment. The challenge, therefore, is to concisely represent to the user the behaviour of a particular implementation, and the differences between this implementation and alternative versions. Inferred models of software behaviour – and automatically derived and graphically presented comparisons between them – serve to support effective decision making in situations where there are competing implementations of requirements. In this paper we use state machine models as the abstract representation of the behaviour of an implementation, and using these we build a tool by which one can visualise in an intuitive manner both the initial implementation and the differences between alternative versions. In this paper we describe our tool Synapse which implements this functionality by means of our grammar inference tool StateChum and a model-differencing algorithm. We describe the main functionality of Synapse, and demonstrate its usage by comparing different implementations of an example program from the existing literature