The Distributive Impact of the Water Market in Chile: A Case Study in Limari Province, 1981- 1997

The introduction of a strong market-oriented economic policy after the 1973 golpe in Chile led to economic reforms during the 1980s, characterised by deregulation, decentralisation and privatisation of several economic sectors. The reform of the water sector took place as part of this trend. Its overall objective was to increase water-use efficiency, implementing a private management model based on the development of water markets. The model represents the most profound reform that has ever been carried out worldwide in this sector, due to its radical neo-liberal conception and to its duration (in force since 1981). Many studies have been carried out focusing mainly on the efficiency impact of the reform but no one on its distributive effects. This paper aims to fill this gap. The case study (Limarí Province, IV Region) examines the distributive impacts on the relevant population (in particular on the poor and the most vulnerable groups, like peasants) through the analysis of all water use rights transactions which have taken place in the area from 1981 to 1997, and the determinants of peasants' participation in water market, using survey data from a significant sample (2.4%) of peasant households in the area. The study shows that the distribution of water rights has worsened since 1981. Namely, peasants' share of water rights decreased significantly as time went on, both in aggregate and per capita terms, undermining their agricultural production potential and leading to a deterioration of their standards of living. Moreover, the share in water rights by the agricultural sector as a whole decreased, while that by non-agricultural sectors increased. The study shows also that peasants access water resources primarily through the claim of original rights and enter only marginally the water market, usually as sellers, showing a weak bargaining power. Their behaviour in the water market is determined by well identified social, economic and institutional variables, such as the age of the head of household, the educational level of the family, the participation in agricultural organisations, the managerial positions in water users' associations, the access to information in local water market, the access to credit and the crop mix

Characterizing PSPACE with Shallow Non-Confluent P Systems

In P systems with active membranes, the question of understanding the power of non-confluence within a polynomial time bound is still an open problem. It is known that, for shallow P systems, that is, with only one level of nesting, non-con uence allows them to solve conjecturally harder problems than con uent P systems, thus reaching PSPACE. Here we show that PSPACE is not only a bound, but actually an exact characterization. Therefore, the power endowed by non-con uence to shallow P systems is equal to the power gained by con uent P systems when non-elementary membrane division and polynomial depth are allowed, thus suggesting a connection between the roles of non-confluence and nesting depth

Characterizing PSPACE with Shallow Non-Confluent P Systems

In P systems with active membranes, the question of understanding the power of non-confluence within a polynomial time bound is still an open problem. It is known that, for shallow P systems, that is, with only one level of nesting, non-con uence allows them to solve conjecturally harder problems than con uent P systems, thus reaching PSPACE. Here we show that PSPACE is not only a bound, but actually an exact characterization. Therefore, the power endowed by non-con uence to shallow P systems is equal to the power gained by con uent P systems when non-elementary membrane division and polynomial depth are allowed, thus suggesting a connection between the roles of non-confluence and nesting depth

Snowfall series of Turin, 1784-1992: climatological analysis and action on structures

The snowfall series of Turin, northwest Italy, is one of the longest available for Europe, with daily observations starting in 1784 and continuous since 1788. The unpublished 207 years data set was carefully obtained from original manuscripts and filed on magnetic media. Mean yearly snowfall amount is 48.9 cm showing a high interannual variability (variation coefficient 79%), with about seven snow days from October through April; the maximum amount was measured in winter 1784–85 (233 cm), followed by 1808–9 with 163 cm. Maximum daily amount was on 4 December 1844 with 64 cm. During the whole period a negative trend is exhibited, increasing in the years following 1890. This pattern is confirmed by the Mann-Kendall test. The change derives from regional climate rather than expansion of the urban area. Return periods of yearly maximum snow loads are calculated in order to contribute to the definition of new values for structural design. A case study of heavy snowfall in January 1987 is examined

Three Quantum Algorithms to Solve 3-SAT

We propose three quantum algorithms to solve the 3-SAT NP-complete decision problem. The first algorithm builds, for any instance Á of 3-SAT, a quantum Fredkin circuit that computes a superposition of all classical evaluations of Á in a given output line. Similarly, the second and third algorithms compute the same superposition on a given register of a quantum register machine, and as the energy of a given membrane in a quantum P system, respectively. Assuming that a specific non-unitary operator, built using the well known creation and annihilation operators, can be realized as a quantum gate, as an instruction of the quantum register machine, and as a rule of the quantum P system, respectively, we show how to decide whether Á is a positive instance of 3-SAT. The construction relies also upon the assumption that an external observer is able to distinguish, as the result of a measurement, between a null and a non-null vector