Economic growth and pollution patterns: A discussion

En este documento se discuten ampliamente los resultados y aplicaciones de dos modelos de gran relevancia en el análisis económico de los patrones de contaminación. En los dos trabajos expuestos se destacan de forma importante los aspectos ínter temporales para el análisis de los problemas de contaminación. En el primer trabajo (Keller, et al. 1971) se discuten dos modelos posibles, dependiendo de cómo se considera el contaminante dentro de la función de utilidad social y en el proceso productivo. En el segundo documento (Shafik y Bandyopadhyay, 1992), se busca determinar cómo cambia la calidad ambiental a diferentes niveles de ingreso, tomando en cuenta que el ingreso es una variable que está altamente relacionada con los niveles de crecimiento de las sociedades. En ambos modelos lo que se desea es controlar el nivel de stock del contaminante. Ambos modelos difieren en la estructura de su función de producción y en la forma en que permiten controlar el contaminante, sin embargo la función objetivo en ambos es la misma. En general se concluye que las variables de decisión política tales como el comercio, distorsiones o la deuda externa tienen poco o nulo efecto sobre la evolución de la calidad ambiental; las acciones por organismos de control (gobiernos) sólo tomarán acciones cuando existen costos locales generalizados y beneficios (tanto privados como sociales) sustanciales; y que cuando los costos de la degradación ambiental son soportados por otros (por los pobres o por otros países), existen pocos incentivos para cambiar el comportamiento individual destructivo.Abstract : This paper will discuss extensively the results and applications of two models of great significance in economic analysis of patterns of pollution. Both papers highlight the importance of inter-temporal analysis in pollution problems. In the first document (Keller, et al. 1971) two possible models are introduced, depending on how the contaminant is introduce in the utility function and the production process. The second document (Shafik and Bandyopadhyay, 1992), seeks to determine how the environmental quality changes at different income levels, taking into account that income is a variable that is highly related to societies growth. In both models we want to control the level of stock of the pollutant. Both models differ on the structure of its production function and in how to control the pollutant; however the objective function is the same in both. In general we conclude that the decision variables such as trade policy, distortions or external debt have little or no effect on the evolution of environmental quality; control bodies (government) will take action only when there is widespread local costs and substantial benefits (both private and social); and when the costs of environmental degradation are borne by others (for the poor or by other countries), there is little incentive to change the destructive individual behavior

Cognition as Embodied Morphological Computation

Cognitive science is considered to be the study of mind (consciousness and thought) and intelligence in humans. Under such definition variety of unsolved/unsolvable problems appear. This article argues for a broad understanding of cognition based on empirical results from i.a. natural sciences, self-organization, artificial intelligence and artificial life, network science and neuroscience, that apart from the high level mental activities in humans, includes sub-symbolic and sub-conscious processes, such as emotions, recognizes cognition in other living beings as well as extended and distributed/social cognition. The new idea of cognition as complex multiscale phenomenon evolved in living organisms based on bodily structures that process information, linking cognitivists and EEEE (embodied, embedded, enactive, extended) cognition approaches with the idea of morphological computation (info-computational self-organisation) in cognizing agents, emerging in evolution through interactions of a (living/cognizing) agent with the environment

Supraorganized Collagen Enhances Schwann Cell Reactivity And Organization In Vitro.

We investigated the reactivity and expression of basal lamina collagen by Schwann cells (SCs) cultivated on a supraorganized bovine-derived collagen substrate. SC cultures were obtained from sciatic nerves of neonatal Sprague-Dawley rats and seeded on 24-well culture plates containing collagen substrate. The homogeneity of the cultures was evaluated with an SC marker antibody (anti-S-100). After 1 week, the cultures were fixed and processed for immunocytochemistry by using antibodies against type IV collagen, S-100 and p75NTR (pan neurotrophin receptor) and for scanning electron microscopy (SEM). Positive labeling with antibodies to the cited molecules was observed, indicating that the collagen substrate stimulates SC alignment and adhesion (collagen IV labeling - organized collagen substrate: 706.33 ± 370.86, non-organized collagen substrate: 744.00 ± 262.09; S-100 labeling - organized collagen: 3809.00 ± 120.28, non-organized collagen: 3026.00 ± 144.63, P < 0.05) and reactivity (p75NTR labeling - organized collagen: 2156.33 ± 561.78, non-organized collagen: 1424.00 ± 405.90, P < 0.05; means ± standard error of the mean in absorbance units). Cell alignment and adhesion to the substrate were confirmed by SEM analysis. The present results indicate that the collagen substrate with an aligned suprastructure, as seen by polarized light microscopy, provides an adequate scaffold for SCs, which in turn may increase the efficiency of the nerve regenerative process after in vivo repair.44682-

Towards Autopoietic Computing

A key challenge in modern computing is to develop systems that address complex, dynamic problems in a scalable and efficient way, because the increasing complexity of software makes designing and maintaining efficient and flexible systems increasingly difficult. Biological systems are thought to possess robust, scalable processing paradigms that can automatically manage complex, dynamic problem spaces, possessing several properties that may be useful in computer systems. The biological properties of self-organisation, self-replication, self-management, and scalability are addressed in an interesting way by autopoiesis, a descriptive theory of the cell founded on the concept of a system's circular organisation to define its boundary with its environment. In this paper, therefore, we review the main concepts of autopoiesis and then discuss how they could be related to fundamental concepts and theories of computation. The paper is conceptual in nature and the emphasis is on the review of other people's work in this area as part of a longer-term strategy to develop a formal theory of autopoietic computing.Comment: 10 Pages, 3 figure

From Adaptive to More Dynamic Control in Evolutionary Algorithms

Adaptive evolutionary algorithms have been widely developed to improve the management of the balance between intensification and diversification during the search. Nevertheless, this balance may need to be dynamically adjusted over time. Based on previous works on adaptive operator selection, we investigate in this paper how an adaptive controller can be used to achieve more dynamic search scenarios and what is the real impact of possible combinations of control components. This study may be helpful for the development of more autonomous and efficient evolutionary algorithms

An experimental study of adaptive control for evolutionary algorithms

In this paper, we investigate how adaptive operator selection techniques are able to efficiently manage the balance between exploration and exploitation in an evolutionary algorithm, when solving combinatorial optimization problems. We introduce new high level reactive search strategies based on a generic algorithm\u27s controller that is able to schedule the basic variation operators of the evolutionary algorithm, according to the observed state of the search. Our experiments on SAT instances show that reactive search strategies improve the performance of the solving algorithm

Geoquimica de las aguas del rio elqui y de sus tributarios en el per\uedodo 1975-1995: Factores naturales y efecto de las explotaciones mineras en sus contenidos de Fe, Cu y As

The present study discusses the results of 20 years (1975-1995) of chemical analysis of waters of the Elqui river and its tributaries, performed by the Direcci\uf3n General de Aguas - the national waters authority. This discussion is complemented with the results of recent studies of the geochemistry of the sediment of its basin. Among the principal conclusions attained, are the high contents of Cu and As of the Toro, Turbio and Elqui rivers, that receive a direct (Toro river) or indirect contribution of the Malo river, which drains the hydrothermal alteration zone of the Au-Cu-As deposits of the El Indio mining district. The growing intensification of the mining and metallurgical activities at El Indio coincided with increasing contents of Cu and As in the Toro, Turbio and Elqui rivers, though they are progressively attenuated for As due to the diluent effects of low-mineralized tributary river waters. On the other hand, the Elqui river has received significant amounts of Cu from the Talcuna mining district in the Quebrada Marquesa ravine. Though the mining activities at El Indio probably contributed to the increase in As, Cu and Fe contents of the waters, these and other heavy metals have been present in the acid drainage water of the Malo river long before the beginning of said activities. Likewise, the Malo river will continue to be a pollution source after the closure - already completed -of the El Indio mining district.El presente trabajo expone y discute los resultados de veinte a\uf1os (1975-1995) de an\ue1lisis de aguas del R\uedo Elqui y sus tributarios, realizados por la Direcci\uf3n General de Aguas. Su discusi\uf3n se complementa con la de resultados de estudios recientes de la geoqu\uedmica de los sedimentos de la misma cuenca. Entre sus principales conclusiones destaca la alta concentraci\uf3n de Cu y As de los r\uedos Toro, Turbio y Elqui, que reciben el aporte directo (R\uedo Toro) o indirecto de las aguas del R\uedo Malo, que drena la zona de alteraciones hidrotermales y mineralizaciones de Au-Cu-As del distrito minero de El Indio. La intensificaci\uf3n de las faenas minero-metal\ufargicas de El Indio coincidi\uf3 con incrementos en los contenidos de As y Cu de los r\uedos Toro, Turbio y Elqui, aunque los de As son progresivamente atenuados por el efecto de diluci\uf3n debido al aporte de r\uedos tributarios pobres en ese elemento. Por otra parte, el R\uedo Elqui ha recibido aportes significativos de Cu provenientes del distrito minero de Talcuna, situado en la Quebrada Marquesa. Aunque las actividades mineras de El Indio contribuyeron probablemente a aumentar el contenido de As, Cu y Fe de las aguas, estos y otros metales pesados han estado presentes en las aguas afectadas por drenaje \ue1cido del R\uedo Malo desde mucho tiempo antes de que dichas actividades se iniciaran. Igualmente, el R\uedo Malo continuar\ue1 siendo una fuente contaminante despu\ue9s del cierre - ya completado - del distrito minero de El Indio

Modeling relationships between calving traits: a comparison between standard and recursive mixed models

<p>Abstract</p> <p>Background</p> <p>The use of structural equation models for the analysis of recursive and simultaneous relationships between phenotypes has become more popular recently. The aim of this paper is to illustrate how these models can be applied in animal breeding to achieve parameterizations of different levels of complexity and, more specifically, to model phenotypic recursion between three calving traits: gestation length (GL), calving difficulty (CD) and stillbirth (SB). All recursive models considered here postulate heterogeneous recursive relationships between GL and liabilities to CD and SB, and between liability to CD and liability to SB, depending on categories of GL phenotype.</p> <p>Methods</p> <p>Four models were compared in terms of goodness of fit and predictive ability: 1) standard mixed model (SMM), a model with unstructured (co)variance matrices; 2) recursive mixed model 1 (RMM1), assuming that residual correlations are due to the recursive relationships between phenotypes; 3) RMM2, assuming that correlations between residuals and contemporary groups are due to recursive relationships between phenotypes; and 4) RMM3, postulating that the correlations between genetic effects, contemporary groups and residuals are due to recursive relationships between phenotypes.</p> <p>Results</p> <p>For all the RMM considered, the estimates of the structural coefficients were similar. Results revealed a nonlinear relationship between GL and the liabilities both to CD and to SB, and a linear relationship between the liabilities to CD and SB.</p> <p>Differences in terms of goodness of fit and predictive ability of the models considered were negligible, suggesting that RMM3 is plausible.</p> <p>Conclusions</p> <p>The applications examined in this study suggest the plausibility of a nonlinear recursive effect from GL onto CD and SB. Also, the fact that the most restrictive model RMM3, which assumes that the only cause of correlation is phenotypic recursion, performs as well as the others indicates that the phenotypic recursion may be an important cause of the observed patterns of genetic and environmental correlations.</p