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International audience; We propose a new approach of cellular automata models, based on a graph frame, which allows the modelling of irregular and dynamic neighbourhood of spatial entities. The Remus model permits the computation of a graph representing the buildings and the transportation network (the urban graph), and thus the calculation of the network distance-time between buildings. This model allows the extraction of various graphs, including the functional graph of the network-time-distances between buildings, and the neighbourhood-relationships graph which represents the network-neighbourhoods according to a certain time-distance-threshold and a given transportation mode.

We establish uniform continuity of the value for zero-sum games with differential information, when the distance between changing information fields of each player is measured by the Boylan pseudometric. We also show that the optimal strategy correspondence is upper semicontinuous when the information fields of players change (even with the weak topology on players' strategy sets), and is approximately lower semicontinuous.

Currently there is a need for a model to estimate mass emissions of atmospheric pollutants at the exit of the stacks of thermal power plants that operate under a variable regime of electric power generation based on the variables that typically are monitored during the operation of the plants. The recommended alternative to calculate the mass emissions of pollutants is based on the experimental measurements of pollutant concentration, velocity and temperature at the exit of the stack. This alternative is expensive and cumbersome to implement. Alternatively the US EPA emission factors can be used. However, the emission factors require modifications to account for the type of fuel, the technology used to control emissions, maintenance of the equipment, and the local environmental conditions. As a solution, this paper presents a model to estimate emissions of atmospheric pollutants in thermal power plants based on the variables that are continuously monitored during the operation of most of the thermal power plants in Mexico such as fuel chemical composition, fuel consumption, air to fuel ratio of the combustion process, and mean boiler temperature. The proposed model was calibrated by continuously measuring all the variables included in the three models during one week of operation of a 2.2 GW thermal power plant located in the continental area of the Gulf of Mexico. This plant has six units of generation that operate with fuel oil and one with natural gas. Results obtained from the three methodologies described before were compared. It was concluded that the NOx, SOx and CO results of the proposed model follow closely the results obtained using the measurements of concentration, velocity and temperature at the exit of the stack method. It was also found that the results of the emission factors methodology require to be adjusted to include the particular operating conditions of each unit of electricity generation.Copyright © 2007 by ASME

We show that even in very simple oligopolies with differential information a (Bayesian) Cournot equilibrium in pure strategies may not exist, or be unique. However, we find sufficient conditions for existence, and for uniqueness, of Cournot equilibrium in a certain class of industries. More general results arise when negative prices are allowed.

International audience

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2006. Durante os últimos trinta anos, o monitoramento da saúde estrutural (ou Structural Health Monitoring, SMH) tem-se desenvolvido rapidamente com o objetivo de estabelecer tanto o local do dano quanto a sua magnitude. Esses danos podem ser produzidos nas estruturas pelos processos de deterioração, aos quais estão submetidas durante toda a vida útil, afetando a capacidade de carga e ao mesmo tempo a segurança desta. Nesta dissertação, são aplicados dois métodos baseados nas mudanças das propriedades dinâmicas das estruturas produzidas pelo dano. Para o estudo do método de identificação de dano em estruturas usando a mudança na flexibilidade (Pandey e Biswas, 1994), é feita uma análise numérica em vigas com diferentes condições de apoio, níveis e locais de dano. Já para estruturas reticuladas, é aplicado o método de identificação de dano em estruturas submetidas a vibrações ambientes usando vetores de localização de dano, segundo a metodologia de Bernal (2000), e segundo a metodologia de Gao e Spencer (2002). Neste caso, para a análise numérica, simulam-se cenários de dano simples e múltiplo, variando as porcentagens de dano nos elementos. Inclui-se também uma simulação de um ensaio experimental numa das treliças analisadas numericamente para estudar a aplicabilidade do método e os resultados obtidos. É proposta uma metodologia de quantificação de dano para o método proposto por Bernal (2000) a qual baseia-se no índice MAC (MODAL ASSURRANCE CRITERION) proposto por Allemang e Brown (1982). O método proposto por Pandey e Biswas (1994) permitiu localizar satisfatoriamente o dano em todos os casos estudados. O método de identificação de dano usando vetores de localização apresentou resultados satisfatórios na identificação quando aplicada a metodologia proposta por Bernal (2000). Já quando aplicada a metodologia proposta por Gao e Spencer (2002) os resultados obtidos em alguns casos não representaram fielmente o estado da estrutura. ___________________________________________________________________________________ ABSTRACT During the last thirty years, the Structural Health Monitoring (SHM) has been quickly developed with the purpose of establishing the local damages and its magnitude. The structures are submitted during its useful life to deterioration processes that can produce damages in them, changing their load capacity and at the same time the structure safety. In this dissertation, two methods based on the changes of the dynamic properties produced by damage are applied. For the method of damage identification in structures using the changes in the flexibility (Pandey and Biswas, 1994), is accomplished a numerical analysis when it is applied to beams with different support conditions, levels and localization of damage. In the case of truss structures, the method of damage identification in structures under ambient vibrations using the Damage Locating Vectors (DLVs) proposed by Bernal (2000) and the variation to this method proposed by Gao and Spencer (2002), were applied. In this case, for the numerical analysis, simple and multiple damaged scenarios were simulated, varying the level of damage in the elements. It is also included a simulation of an experimental test in one of the analysed trusses, in order to study the applicability of the method and its results. An approach for damage quantification in the Bernals (2000) methodology is proposed and it is based on the MAC (Modal Assurance Criterion) index developed by Allemang and Brown (1982). The method proposed by Pandey and Biswas (1994) identified the damage in all of the cases studied. The damage identification method using DLVs yield very satisfactory results when the Bernals (2000) methodology is applied, meanwhile the results obtained with the Gao and Spencer (2002) methodology in some cases does not represent the real state of the structure.

52 páginasl, 126 figuras, 1 tabla., [ES] El estudio de los moluscos de agua dulce llevado a cabo en la Comunidad de Madrid permite citar 33 especies, de ellas 25 son de gasterópodos y ocho son de bivalvos. De estas especies, 23 ya habían sido citadas previamente en esta área, aunque la mayoría con otros nombres, bien porque en la actualidad son sinónimos, o bien por determinaciones erróneas. Para las 33 especies, identificadas en un total de 463 muestras analizadas, junto con el estudio de los ejemplares conservados en el Museo Nacional de Ciencias Naturales, se aportan datos taxonómicos y breves descripciones, así como información sobre los habitat en los que se han encontrado. Se indica también si habían sido citados previamente en el área y el nombre asignado por los diferentes autores. De acuerdo con los datos bibliográficos manejados, un total de nueve especies se citan por primera vez en la región: Pseudamnicola (Pseudamnicola) subproducta, Pseudamnicola (Corrosella) hinzi, Lymnaea stagnalis, Stagnicola palustris, Gyraulus (Gyraulus) chinensis, Gyraulus (Torquis) laevis, Ferrissia (Pettancylus) clessiniana, Oxyloma (Oxyloma) sarsii y Pisidium subtruncatum. Entre las especies citadas por otros autores, cabe mencionar que “Islamia” coronadoi, Anisus (Disculifer) vortex y Segmentina nitida, no han podido ser localizadas. Stagnicola palustris se cita por primera vez, aunque sólo se han encontrado conchas. Dos especies, Potamopyrgus antipodarum y Gyraulus chinensis, son introducidas; la primera de ellas, considerada como invasora, presenta una amplia distribución. Del mismo modo citamos Lymnaea stagnalis y Oxyloma (Oxyloma) sarsii, que sólo se han encontrado en un centro de jardinería, por si incidentalmente pudieran extenderse a hábitats naturales en la región., [EN] In this study of freshwater molluscs carried out in Comunidad de Madrid we cite the presence of 33 species, of which 25 are gastropods and eight bivalves. Twentythree of these species were previously reported in this area although most of them with different names either because they are synonyms or because they were determinated erronoeusly. The 33 species were identified from a total of 463 samples together with the specimens preserved at the Museo Nacional de Ciencias Naturales. Taxonomical data and short descriptions, as well as information about the habitats in which they were found is given for the 33 species. We also indicate if they were previously reported in the area and names given by authors. According to the bibliographic data used, a total of nine species are cited for the first time in the region: Pseudamnicola (Pseudamnicola) subproducta, Pseudamnicola (Corrosella) hinzi; Lymnaea stagnalis; Stagnicola palustris; Gyraulus (Gyraulus) chinensis, Gyraulus (Torquis) laevis, Ferrissia (Pettancylus) clessiniana, Oxyloma (Oxyloma) sarsii and Pisidium subtruncatum. Among the previous records, it is worth mentioning that it was not possible to locate “Islamia” coronadoi, Anisus (Disculifer) vortex and Segmentina nitida. Stagnicola palustris, is reported for the first time although only shells were found. Two species, Potamopyrgus antipodarum and Gyraulus chinensis, are alien species. The first of those two species is considered as invasive and presents a wide distribution. Although Lymnaea stagnalis and Oxyloma (Oxyloma) sarsii were only observed in a garden center, we cite them here because there is the possibility that they might accidentally spread out into natural habitats of the region., Los muestreos han sido realizados en el marco de los proyectos “Fauna Ibérica” (Refs. DGICYT, PB87-0397, PB89- 0081, PB92-0121, PB95-0235 y CGL2004-04680-C10-01) y “Evaluación del conocimiento y del estado de conservación de la diversidad animal de Madrid” financiado por la Comunidad de Madrid (Ref. GR/AMB/0750/2004).

The Mexican environmental authority requires that thermal power plants operate 3 or 4 air quality monitoring stations around its main stack to ensure that pollutant concentration levels are always below the maximum allowable. However the high cost of these stations and the cost of their maintenance have made this regulation economically unreasonable. It has been proposed to reduce the number of monitoring stations to one and substitute the other stations by an accurate atmospheric dispersion model that allows the permanent surveillance of the surface pollutant concentration levels around the thermoelectric power plants. CALPUFF, an advanced air pollution dispersion modeling system was implemented for the special case of the Mexican thermal power plants. Experimental work was conducted to verify the correct implementation of the model. This paper describes the main results obtained during the development of this work.

We introduce a simple model of oligopolistic competition where firms first build capacity, and then, after observing the capacity decisions, choose a reservation price at which they are willing to supply their capacities. This model describes many markets more realistically than the model of Kreps and Scheinkman [Kreps, D., Scheinkman, J., 1983. Quantity precommitment and Bertrand competition yield Cournot outcomes. Bell J. Econ. 14, 326–337]. We show that in this new model every pure strategy equilibrium yields the Cournot outcome, and that the Cournot outcome can be sustained by a pure strategy subgame perfect equilibrium. Publicado

The need for an effective and safe medical treatment of nonalcoholic fatty liver disease is urgent due to its high prevalence and progressive character. At the moment, therapeutic strategies are largely empirical and based on the control of associated clinical conditions (especially obesity, type 2 diabetes mellitus, and hypertriglyceridemia) and the use of some specific drugs (insulin sensitizing agents, cytoprotectives, antioxidants, and anticytokines) as an attempt to counteract known elements of the pathogenesis. None of these specifics measures have been found to display enough evidence to recommend their clinical use. It is indispensable to join efforts in coordinated networks to define, as soon as possible, the best treatment and the best time to start it.

The challenges of growing prevalence and evident trend to progressive damage of primary nonalcoholic fatty liver disease confront a poorly understood pathogenesis. It appears to develop in two steps. First, a high adipocyte protein production in the context of a silent inflammatory background causes insulin resistance in adipose tissue. It leads both to lipolysis, with increase of the circulating and hepatic uptake of free fatty acids, and hyperinsulinemia. Within hepatocytes, the subsequent lipogenesis, together with a decreased secretion of lipoproteins, induces an accumulation of excessive hepatic triglycerides (steatosis), impliying some oxidative damage, but it remain balanced by uncoupling protein upregulation and antioxidant systems activation. Second, a more forceful fat catabolism by beta and omega oxidation results in respiratory chain hyperactivity with overproduction of free radicals and reactive oxygen species that exceed the antioxidant capacity. These agents lead to hepatocellular injury and necrosis, inflammatory infiltration and fibrosis (steatohepatitis) through induction of Fas ligand and cytokines (tumor necrosis factor alpha, transforming growth factor beta, interleukin-8), and lipid peroxidation and by-products (malondialdehyde and 4-hydroxynonenal). Other mechanisms (hepatic iron, Kupffer cells dysfunction or endotoxemia) play uncertain roles.

Summary. We study the core and competitive allocations in exchange economies with a continuum of traders and differential information. We show that if the economy is “irreducible”, then a competitive equilibrium, in the sense of Radner (1968, 1982), exists. Moreover, the set of competitive equilibrium allocations coincides with the “private core” (Yannelis, 1991). We also show that the “weak fine core” of an economy coincides with the set of competitive allocations of an associated symmetric information economy in which the traders information is the joint information of all the traders in the original economy.

We study upper semi-continuity of the private and coarse core and the Walrasian expectations equilibrium correspondences for economies with differential information, with Boylan (1971) topology on agents information fields. Publicado

We derive alternative sufficient conditions for the value of public information to be either positive or negative in a Cournot duopoly where firms technology exhibits constant returns to scale. Publicado

We characterize the dynamics of trading patterns and market composition when trade is bilateral, finding a trading partner is costly, prices are determined by bargaining, and preferences are private information. We show that equilibrium is inefficient and exhibits delay as sellers price discriminate between buyers with different values. As frictions vanish, transaction prices are asymptotically competitive and the welfare loss of inefficient trading approaches zero, even though the trading patterns continue to be inefficient and delay persists. Journal of Economic Literature Classification Numbers: D40, D50. © 2002 Elsevier Science (USA).

Consider an oligopolistic industry where firms have access to the same technology but are asymmetrically informed about the environment. Even though it is commonplace to think that in this context superior information leads to higher profits, we find that under Cournot competition this is not generally the case: It holds when firms' technology exhibits constant returns to scale, but it does not necessarily hold otherwise. Journal of Economic Literature Classification Numbers: C72, D43, L13.

We study the Mas-Colell bargaining set of an exchange economy with differential information and a continuum of traders. We established the equivalence of the private bargaining set and the set of Radner competitive equilibrium allocations. As for the weak fine bargaining set, we show that it contains the set of competitive equilibrium allocations of an associated symmetric information economy in which each trader has the “joint information” of all the traders in the original economy, but unlike the weak fine core and the set of fine value allocations, it may also contain allocations which are not competitive in the associated economy. Publicado

We study the core and competitive allocations in exchange economies with a continuum of traders and differential information. We show that if the economy is “irreducible”, then a competitive equilibrium, in the sense of Radner (1968, 1982), exists. Moreover, the set of competitive equilibrium allocations coincides with the “private core” (Yannelis, 1991). We also show that the “weak fine core” of an economy coincides with the set of competitive allocations of an associated symmetric information economy in which the traders information is the joint information of all the traders in the original economy. Publicado

We study the relationship between the set of rational expectations equilibrium allocations and the ex-post core of exchange economies with asymmetric information.

We study the core of a non-atomic game v which is uniformly continuous with respect to the DNA-topology and continuous at the grand coalition. Such a game has a unique DNA-continuous extension ${\overline {v}}$ on the space B1 of ideal sets. We show that if the extension ${\overline {v}}$ is concave then the core of the game v is non-empty iff ${\overline {v}}$ is homogeneous of degree one along the diagonal of B1. We use this result to obtain representation theorems for the core of a non-atomic game of the form v=fˆ µ where µ is a finite dimensional vector of measures and f is a concave function. We also apply our results to some non-atomic games which occur in economic applications.

A fundamental problem in public finance is that of allocating a␣given budget to financing the provision of public goods (education, transportation, police, etc.). In this paper it is established that when␣admissible preferences are those representable by continuous and increasing utility functions, then strategy-proof allocation mechanisms whose (undominated) range contains three or more outcomes are dictatorial on the set of profiles of strictly increasing utility functions, a dense subset of the domain in the topologies commonly used in this context. If admissible utility functions are further restricted to be strictly increasing, or if mechanisms are required to be non-wasteful, then strategy-profness leads to (full) dictatorship. Publicado

This paper reports the results of an experiment designed to test the usefulness of alternative solution concepts to explain players' behavior in noncooperative games with preplay communication. In the experiment subjects communicate by plain conversation prior to playing a simple game. In this setting, we find that the presumption of individualistic and independent behavior underlying the concept of Nash equilibrium is inappropriate. Instead, we observe behavior to be coordinated and correlated. Statistical tests reject Nash equilibrium as an explanation of observed play. The coalition proof correlated equilibrium of the game, however, explains the data when the possibility of errors by players is introduced. Journal of Economic Literature Classification Numbers: C72, C92. © 1998 Academic Press.

Objetivos: Caracterizar las moléculas de respuesta humoral anti Paragonimus mexicanus/P. peruvianus para diferenciar la infección en fase aguda y fase crónica, mediante la evaluación de la dinámica de la respuesta inmune. Diseño: Observacional, longitudinal. Institución: Instituto de Medicina Tropical Daniel A. Carrión, Facultad de Medicina, UNMSM Material biológico: Animales de experimentación. Principales medidas de resultados: Determinación de IgG e IgM anti Paragonimus. Resultados: Existió diferencia significativa de medias de la DO entre los grupos crónico y no infectados para los anticuerpos IgG anti ES de Paragonimus. Los anticuerpos IgM anti Paragonimus tuvieron una ligera elevación entre los días 7 a 20 post inoculación (pi), y una tendencia hacia la disminución entre los días 40 y 60 pi. Conclusiones: La dinámica de producción de anticuerpos IgG e IgM anti Paragonimus mediante Elisa indirecto, diferenció la fase aguda de la fase crónica, en los gatos inoculados.

We characterize the agreements that the players of a noncooperative game may reach when they can communicate prior to play, but they cannot reach binding agreements: A coalition-proof equilibrium is a correlated strategy from which no coalition has an improving and self-enforcing deviation. We show that any correlated strategy whose support is contained in the set of actions that survive the iterated elimination of strictly dominated strategies and weakly Pareto dominates every other correlated strategy whose support is contained in that set, is a coalition-proof equilibrium. Consequently, the unique equilibrium of a dominance solvable game is coalition-proof. Journal of Economic Literature Classification

Several recent studies of the way individual economic units might learn their parts in an economic or strategic equilibrium have modeled the learning process as a recursive algorithm with stochastic features. The central idea in each of these studies has been to explain or justify the notion of equilibrium by demonstrating that an equilibrium is a stationary point to which the learning process converges. This approach to equilibrium analysis—and in particular the modelling of learning in terms of a recursive stochastic algorithm—seems attractive and powerful, and we expect its use to become more widespread.

In the social choice literature studying the problem of designing institutions for collective decision making, it is customary to (implicitly) assume that each dimension of the social outcome is of public interest (i.e., that each individual's welfare depends on every dimension of the outcome). Thus, the scope of the conclusions obtained is very limited. Here social decision problems with and without that public character are considered and it is shown that the same negative results arise in most cases; namely, that only dictatorial mechanisms are immune to the participants' manipulations. These results are obtained without requiring that the mechanisms produce Pareto optimal outcomes (they must simply be minimally responsive to the participants' preferences), which deepens their pessimistic character. Publicado

Recent papers by Barberá and Peleg and by Zhou have established that the Gibbard-Satterthwaite Theorem remains valid when individuals are restricted to reporting only reasonable preferences. We present a theorem that covers situations in which, as in Barberá-and-Peleg and Zhou, preferences may be restricted to reasonable ones, but in which, additionally, it may be known in advance that some dimensions of the social decision do not affect all the participants — i.e., in which the social decisions are partially decomposable into decisions that affect only subsets of the participants. As in the previous theorems, the conclusion of this new theorem is that nonmanipulable voting schemes must be dictatorial. Publicado

A new record of Phyllariopsis purpurascens (C. Agardh) Henry et South from AlmeríaPalabras clave. Phyllariopsis, corología, Península Ibérica.Key words. Phyllariopsis, geographical distribution, Iberian Peninsula.