¿Puede la depredación de nidos explicar la falta de defensas de Zonotrichia capensis contra el parasitismo de cría de M. Bonariensis?

Although interspecific avian brood parasitism usually lowers host productivity, some species lack any defense against parasites. We analyzed the effect of parasite egg removal or nest desertion following a parasitism event on the breeding productivity of the Rufous-collared Sparrow (Zonotrichia capensis), a common host of the Shiny Cowbird (Molothrus bonariensis). The Rufouscollared Sparrow is an effective cowbird host that does not eject parasite eggs. We removed cowbird eggs from nests of Rufouscollared Sparrows to test for differences in hatching, fledging, and nesting success among naturally unparasitized, parasitized, and experimentally unparasitized nests from which we removed the cowbird eggs. We also used simulations to test whether parasite egg removal or nest desertion provide viable strategies to counter the effects of parasitism in this species. Naturally unparasitized nests produced more nestlings and fledglings than parasitized and experimentally unparasitized nests, but there were no differences between parasitized nests and those from which cowbird eggs were removed. Moreover, the overall nesting success was similar for all nest types. Simulation models confirmed these results but also showed that productivity may still increase through parasite egg ejection when the nest predation rate is relaxed only if no cost of parasite egg ejection is assumed. By contrast, nest desertion was not a viable strategy to reduce the effect of parasitism. We suggest that high nest predation could reduce the benefits of antiparasite defenses in the Rufouscollared Sparrow and may help explain the lack of such behavior in this species.A pesar de que el parasitismo de cría interespecífico usualmente reduce la productividad de las especies hospedadoras, algunas de estas especies carecen de defensas contra los parásitos. En este trabajo analizamos el efecto que la remoción de huevos de los parásitos de cría y la deserción del nido siguiendo un evento de parasitismo podrían tener sobre la productividad de Zonotrichia capensis, una especie hospedadora común de Molothrus bonariensis. Esta especie es un hospedador efectivo de M. bonariensis y no rechaza los huevos del parásito de su nido. Realizamos la remoción de los huevos del parásito de nidos de Z. capensis, y comparamos el éxito de eclosión, de volantoneo y de nidificación de nidos naturalmente no parasitados, nidos parasitados y aquellos donde realizamos la remoción del huevo parásito. Además, utilizamos modelos de simulación para evaluar si la remoción de huevos del parásito y la deserción del nido podrían constituir estrategias viables para reducir los efectos del parasitismo de cría en esta especie. Los nidos naturalmente no parasitados produjeron más pichones y volantones que los nidos experimentales ïlos parasitados, pero no existieron diferencias entre estos dos últimos tipos de nidos. Además, el éxito de nidificación fue similar para los distintos tipos de nidos. A pesar de la falta de diferencias detectada en el experimento a campo, los modelos de simulación demostraron también que, cuando la tasa de depredacióon de nidos es menor, la productividad puede aún incrementarse si Z. capensis rechaza los huevos del parásito siempre y cuando no exista un costo en el comportamiento de rechazo. En cambio, la deserción del nido no fue una estrategia viable para reducir el impacto del parasitismo. Sugerimos que la alta tasa de depredación de nidos podría reducir los beneficios de las defensas antiparasitarias en Z. capensis y puede contribuir a explicar la falta de ellas en esta especie.Fil: Carro, Mariana Emilia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernandez, Gustavo Javier. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Effects Of Comprehensive Income On ROE In A Context Of Crisis: Empirical Evidence For IBEX-35 Listed Companies (2004-2008)

Comprehensive income is becoming increasingly important as an indicator of corporate performance at an international level [SFAS 130 by the FASB (1997) and NIC 1 by the IASB, revised in 2007, among others]. Given this importance, this paper intends to assess its impact on the Return on Equity (ROE), as opposed to the more traditional net income, for the period 2004-2008 for the select group of the Spanish IBEX-35 listed companies. Moreover, working on this period will also allow us to verify the incidence of comprehensive income on the ROE within a context of economic crisis, especially for the year 2008, with a large recession and steep drops in the stock markets. For this empirical study, we took as reference the pertinent information disclosed in the Consolidated Annual Reports of these listed companies, formulated pursuant to the IFRS by the IASB, especially pursuant to IAS 1.The non-parametric Wilcoxon Signed-Rank Test was used to perform the corresponding statistic comparisons, as the variables in certain years did not conform to normalcy. The results of our paper show a statistically significant impact of the ROE calculated pursuant to comprehensive income as opposed to the ROE determined pursuant to the net income. This was evidenced for three of the five years that were studied, especially for 2008, when there was a spectacular decline in the ROE calculated pursuant to the comprehensive income as opposed to that calculated pursuant to the net income. We consider this could be a contribution to the international debate regarding the need to include other measurements of corporate performance that are broader than the traditional net income in certain ratios of the fundamental analysis. This could represent the basis for adopting financial decisions that are much more in tune with the reality of the market

A generic persistence model for CLP systems (and two useful implementations)

This paper describes a model of persistence in (C)LP languages and two different and practically very useful ways to implement this model in current systems. The fundamental idea is that persistence is a characteristic of certain dynamic predicates (Le., those which encapsulate state). The main effect of declaring a predicate persistent is that the dynamic changes made to such predicates persist from one execution to the next one. After proposing a syntax for declaring persistent predicates, a simple, file-based implementation of the concept is presented and some examples shown. An additional implementation is presented which stores persistent predicates in an external datábase. The abstraction of the concept of persistence from its implementation allows developing applications which can store their persistent predicates alternatively in files or databases with only a few simple changes to a declaration stating the location and modality used for persistent storage. The paper presents the model, the implementation approach in both the cases of using files and relational databases, a number of optimizations of the process (using information obtained from static global analysis and goal clustering), and performance results from an implementation of these ideas

IDRA (IDeal Resource Allocation): A tool for computing ideal speedups

Performance studies of actual parallel systems usually tend to concéntrate on the effectiveness of a given implementation. This is often done in the absolute, without quantitave reference to the potential parallelism contained in the programs from the point of view of the execution paradigm. We feel that studying the parallelism inherent to the programs is interesting, as it gives information about the best possible behavior of any implementation and thus allows contrasting the results obtained. We propose a method for obtaining ideal speedups for programs through a combination of sequential or parallel execution and simulation, and the algorithms that allow implementing the method. Our approach is novel and, we argüe, more accurate than previously proposed methods, in that a crucial part of the data - the execution times of tasks - is obtained from actual executions, while speedup is computed by simulation. This allows obtaining speedup (and other) data under controlled and ideal assumptions regarding issues such as number of processor, scheduling algorithm and overheads, etc. The results obtained can be used for example to evalúate the ideal parallelism that a program contains for a given model of execution and to compare such "perfect" parallelism to that obtained by a given implementation of that model. We also present a tool, IDRA, which implements the proposed method, and results obtained with IDRA for benchmark programs, which are then compared with those obtained in actual executions on real parallel systems

IDRA (IDeal Resource Allocation): Computing ideal speedups in parallel logic programming

We present a technique to estimate accurate speedups for parallel logic programs with relative independence from characteristics of a given implementation or underlying parallel hardware. The proposed technique is based on gathering accurate data describing one execution at run-time, which is fed to a simulator. Alternative schedulings are then simulated and estimates computed for the corresponding speedups. A tool implementing the aforementioned techniques is presented, and its predictions are compared to the performance of real systems, showing good correlation

Welcoming Foreign Direct Investment? A Political Economy Approach to FDI Policies in Argentina and Brazil

The purpose of this presentation is to develop a framework that enables us to discern the political economy determinants of FDI openness in emerging economies that received large flows of FDI during the past 15 years. Even tough the political economy field is recently thriving with contributions that help us understand the multidisciplinary aspects of foreign investment, our comprehension level is still behind that of international trade. This opens up the door for exciting research opportunities but it also constitutes a tremendous challenge. While the current literature has focused on the “ex-ante” political and economic conditions that can propel FDI openness, it has not considered the extent to which foreign investment, through its impact on the relative price of the domestic factors of production and on the market structure, can stimulate changes in the design of FDI policies. In addition, specific features of emerging economies have not been sufficiently explored in their relationship with FDI. This study seeks to fill in these gaps by using the specific cases of Argentina and Brazil

Welcoming Foreign Direct Investment? A Political Economy Approach to FDI Policies in Argentina and Brazil

The purpose of this presentation is to develop a framework that enables us to discern the political economy determinants of FDI openness in emerging economies that received large flows of FDI during the past 15 years. Even tough the political economy field is recently thriving with contributions that help us understand the multidisciplinary aspects of foreign investment, our comprehension level is still behind that of international trade. This opens up the door for exciting research opportunities but it also constitutes a tremendous challenge. While the current literature has focused on the “ex-ante” political and economic conditions that can propel FDI openness, it has not considered the extent to which foreign investment, through its impact on the relative price of the domestic factors of production and on the market structure, can stimulate changes in the design of FDI policies. In addition, specific features of emerging economies have not been sufficiently explored in their relationship with FDI. This study seeks to fill in these gaps by using the specific cases of Argentina and Brazil

Host plant specificity and feeding preferences of Morpho epistrophus argentinus (Lepidoptera: Nymphalidae) larvae in coastal woodlands of Argentina

The selection of suitable host plants for larval development is critical for most herbivorous insects. In this study, we examined host plant preferences of larvae from Epistrophus white morpho butterfly, Morpho epistrophus argentinus (H. Fruhstorfer), a specialized butterfly that oviposits on a few plant species. In many species, the selection of host plant for larvae development is under the control of ovipositing females and the role of larvae in host selection is minimal. At field, we characterized larval host plant use in coastal woodland patches of its southernmost distribution range (36º 25’ S, 56º 57’ W; Argentina). All sampled M.e. argentinus larvae groups (n = 40) were found on Scutia buxifolia trees, although the number of larval groups did not correlate with cover of this plant at patch scale. Translocation experiments showed that M.e. argentinus larvae translocated to unsuitable host plants had a shorter residence time than those translocated to suitable (i.e. control) hosts. Choice assays made also indicated strong feeding preferences of wild larvae for S. buxifolia leaves. The results highlight the high degree of host specificity of M.e. argentinus by S. buxifolia, and reveal that growing larvae preference for host plant matches that of ovipositing females.La selección de plantas hospedadoras adecuadas para el desarrollo larvario es crítica para la mayoría de los insectos herbívoros. En este estudio, examinamos las preferencias de la planta hospedadora de larvas de la mariposa Bandera Argentina, Morpho epistrophus argentinus (H. Fruhstorfer), una mariposa especializada que ovipone en pocas especies de plantas. En muchas especies, la selección de plantas hospedadoras para el desarrollo de las larvas está bajo el control de las hembras y el papel de las larvas en la selección de hospedadores es mínimo. En el campo, caracterizamos el uso de la planta hospedadora por parte de las larvas en parcelas de bosques costeros de su área de distribución más meridional (36º 25’ S, 56º 57’ W; Argentina). Todos los grupos de larvas de M.e. argentinus muestreados (n = 40) fueron encontrados en árboles de la especie Scutia buxifolia, aunque el número de grupos de larvas no se correlacionó con la cobertura de esta planta a escala de parche. Experimentos de translocación demostraron que las larvas de M.e. argentinus translocadas a plantas hospedadoras inadecuadas tuvieron un tiempo de residencia más corto que las translocadas a hospedadores adecuados (i.e. controles). Ensayos de elección realizados también indicaron fuertes preferencias de alimentación de las larvas por hojas de S. buxifolia. Los resultados resaltan el alto grado de especificidad de M.e. argentinus por el hospedador S. buxifolia y revelan que la preferencia de las larvas por la planta hospedadora coincide con la de las hembras cuando oviponen.Fil: Carro, Mariana Emilia. Universidad Nacional del Comahue. Asentamiento Universidad San Martín de Los Andes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Lacoretz, Mariela Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: de Marsico, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Fernandez, Gustavo Javier. Universidad Nacional del Comahue. Asentamiento Universidad San Martín de Los Andes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

Agent Programming in Ciao Prolog

The agent programming landscape has been revealed as a natural framework for developing “intelligence” in AI. This can be seen from the extensive use of the agent concept in presenting (and developing) AI systems, the proliferation of agent theories, and the evolution of concepts such as agent societies (social intelligence) and coordination

A generic persistence model for CLP systems

This paper describes a model of persistence in (C)LP languages and two different and practically very useful ways to implement this model in current systems. The fundamental idea is that persistence is a characteristic of certain dynamic predicates (i.e., those which encapsulate state). The main effect of declaring a predicate persistent is that the dynamic changes made to such predicates persist from one execution to the next one. After proposing a syntax for declaring persistent predicates, a simple, file-based implementation of the concept is presented and some examples shown. An additional implementation is presented which stores persistent predicates in an external database. The abstraction of the concept of persistence from its implementation allows developing applications which can store their persistent predicates alternatively in files or databases with only a few simple changes to a declaration stating the location and modality used for persistent storage. The paper presents the model, the implementation approach in both the cases of using files and relational databases, a number of optimizations of the process (using information obtained from static global analysis and goal clustering), and performance results from an implementation of these ideas