On the Stability of CSS under the Replicator Dynamic

This paper considers a two-player game with a one-dimensional continuous strategy. We study the asymptotic stability of equilibria under the replicator dynamic when the support of the initial population is an interval. We find that, under strategic complementarities, Continuously Stable Strategy (CSS) have the desired convergence properties using an iterated dominance argument. For general games, however, CSS can be unstable even for populations that have a continuous support. We present a sufficient condition for convergence based on elimination of iteratively dominated strategies. This condition is more restrictive than CSS in general but equivalent in the case of strategic complementarities. Finally, we offer several economic applications of our results.

Evolutionary Stability of First Price Auctions

This paper studies the evolutionary stability of the unique Nash equilibrium of a first price sealed bid auction. It is shown that the Nash equilibrium is not asymptotically stable under payoff monotonic dynamics for arbitrary initial popu- lations. In contrast, when the initial population includes a continuum of strategies around the equilibrium, the replicator dynamic does converge to the Nash equilibrium. Simulations are presented for the replicator and Brown-von Neumann-Nash dynamics. They suggest that the convergence for the replicator dynamic is slow compared to the Brown-von Neumann-Nash dynamics.

Phylogenetic analyses of typical bovine rotavirus genotypes G6, G10, P[5] and P[11] circulating in Argentinean beef and dairy herds

Group A rotavirus (RVA) is one of the main causes of neonatal calf diarrhea worldwide. RVA strains affecting Argentinean cattle mainly possess combinations of the G6, G10, P[5] and P[11] genotypes. To determine RVA diversity among Argentinean cattle, representative bovine RVA strains detected in diarrheic calves were selected from a survey conducted during 1997–2009. The survey covered the main livestock regions of the country from dairy and beef herds. Different phylogenetic approaches were used to investigate the genetic evolution of RVA strains belonging to the prevalent genotypes. The nucleotide phylogenetic tree showed that all genotypes studied could be divided into several lineages. Argentinean bovine RVA strains were distributed across multiple lineages and most of them were distinct from the lineage containing the vaccine strains. Only the aminoacid phylogenetic tree of G6 RVA strains maintained the same lineages as observed at the nucleotide level, whereas a different clustering pattern was observed for the aminoacid phylogenetic trees of G10, P[5] and P[11] suggesting that the strains are more closely related at the aminoacid level than G6 strains. Association between P[5] and G6(IV), prevalent in beef herd, and between P[11] and G6(III) or G10 (VI and V), prevalent in dairy herds, were found. In addition, Argentinean G6(III), G10, P[5] and P[11] bovine RVA strains grouped together with human strains, highlighting their potential for zoonotic transmission. Phylogenetic studies of RVA circulating in animals raised for consumption and in close contact with humans, such as cattle, contribute to a better understanding of the epidemiology of the RVA infection and evolution.Fil: Badaracco, Alejandra. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garaicoechea, Lorena Laura. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Matthijnssens, J.. University of Leuven. Rega Institute for Medical Research; BélgicaFil: Louge Uriarte, Enrique Leopoldo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; ArgentinaFil: Bilbao, Gladys Noemí. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Fernandez, Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Parra, G. I.. National Institutes of Health; Estados UnidosFil: Parreño, Gladys Viviana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

On the stability of CSS under the replicator dynamic

Louge F. On the stability of CSS under the replicator dynamic. Working Papers. Institute of Mathematical Economics. Vol 436. Bielefeld: Universität Bielefeld; 2010.This paper considers a two-player game with a one-dimensional continuous strategy. We study the asymptotic stability of equilibria under the replicator dynamic when the support of the initial population is an interval. We find that, under strategic complementarities, Continuously Stable Strategy (CSS) have the desired convergence properties using an iterated dominance argument. For general games, however, CSS can be unstable even for populations that have a continuous support. We present a sufficient condition for convergence based on elimination of iteratively dominated strategies. This condition is more restrictive than CSS in general but equivalent in the case of strategic complementarities. Finally, we offer several economic applications of our results

Evolutionary stability of first price auctions

Louge F, Riedel F. Evolutionary stability of first price auctions. Working Papers. Institute of Mathematical Economics. Vol 435. Bielefeld: Universität Bielefeld; 2010.This paper studies the evolutionary stability of the unique Nash equilibrium of a first price sealed bid auction. It is shown that the Nash equilibrium is not asymptotically stable under payoff monotonic dynamics for arbitrary initial populations. In contrast, when the initial population includes a continuum of strategies around the equilibrium, the replicator dynamic does converge to the Nash equilibrium. Simulations are presented for the replicator and Brown-von Neumann-Nash dynamics. They suggest that the convergence for the replicator dynamic is slow compared to the Brown-von Neumann-Nash dynamics

Evolutionary Stability in First Price Auctions

Louge F, Riedel F. Evolutionary Stability in First Price Auctions. Dynamic Games and Applications. 2012;2(1):110-128.This paper studies the evolutionary stability of the unique Nash equilibrium of a first price sealed bid auction. It is shown that the Nash equilibrium is not asymptotically stable under payoff monotonic dynamics for arbitrary initial populations. In contrast, for some classes of bid functions, when the initial population includes a continuum of strategies around the equilibrium, the replicator dynamic does converge to the Nash equilibrium. Simulations are presented for the replicator and Brown–von Neumann–Nash (BNN) dynamics. They suggest that the convergence for the replicator dynamic is slow compared to that for the BNN dynamic

Bovine rotavirus strains circulating in beef and dairy herds in Argentina from 2004 to 2010

Bovine Group A Rotavirus (RVA) is one of the main causes of neonatal calf diarrhea worldwide. The present study reports the genotyping of bovine RVA strains circulating in Argentinean cattle from 2004 to 2010. Additionally, a new set of typing primers was designed and tested to differentiate between G8 and G6 (lineage III and IV) RVA strains. Bovine RVA was detected in 30% (435/1462) of the tested samples, corresponding to 49% (207/423) of the studied outbreaks with a similar detection rates in beef (53%; 67/127) and dairy herds (52%; 65/126). The RVA strains circulating in Argentinean cattle belonged to the common bovine genotypes G6 (lineages III and IV), G8, G10, P[5] and P[11]. A different RVA G/P-genotype distribution was found between the exploitation types, with the combination G6(IV)P[5] being by fare the most prevalent RVA strain in beef herds (58%), whereas a more even distribution of G6(III)P[11] (15%), G10P[11] (17%), G6(IV)P[5] (14%), and G6(IV)P[11] (6%) RVA strains was detected in dairy herds. G8 RVA strains were found in two dairy farms in calves co-infected with G8+G6(III)P[11]. A high percentage of co-infections and co-circulation of RVA strains with different genotypes during the same outbreak were registered in both exploitation types (20% of the outbreaks from beef herds and 23% from dairy herds), indicating a potential environment for reassortment. This finding is significant because G10P[11] and G6(III)P[11] strains may possess zoonotic potential. Continuous surveillance of the RVA strains circulating in livestock provides valuable information for a better understanding of rotavirus ecology and epidemiology.Instituto de VirologíaFil: Badaracco, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Garaicoechea, Lorena Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Rodriguez, Daniela Vanesa. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Louge Uriarte, Enrique Leopoldo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Odeon, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Bilbao, Gladys. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Galarza, Roxana Ivon. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Abdala, Alejandro Ariel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Fernandez, Fernando Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Parreño, Gladys Viviana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; Argentin

Epidemic abortions due to Neospora caninum infection in farmed red deer (Cervus elaphus)

This study describes for the first time an abortion outbreak caused by Neospora caninum in farmed red deer. During a 5-year period, farmed hinds, naturally mated, were regularly ultrasound monitored to detect reproductive losses over their gestation. During the 4 years previous to the outbreak, abortion rates ranged from 4.7 to 8.6% (average 6.5%), and serology for indirect diagnosis of neosporosis and toxoplasmosis was performed. At the fifth year, the abortion rate increased to 25.3%. During this outbreak, three aborted foetuses and their placentas were recovered and submitted to laboratory for etiological diagnosis. Blood samples were collected from the 81 hinds at the end of the gestational period and the seropositivity rate for N. caninum, Toxoplasma gondii, Brucella abortus, bovine viral diarrhoea virus and bovine alphaherpesvirus type 1 was 66.7%, 67.9%, 0.0%, 8.6% and 0.0%, respectively. Neospora caninum-seropositive hinds (OR = 5.7, P = 0.0271) and hinds with high antibody titres to N. caninum (OR = 7.4, P = 0.0130) were more likely to abort than seronegative hinds. In addition, N. caninum seropositivity rate in the aborted hinds was higher (OR = 5.4, P = 0.033) than the non-aborted hinds. No association was found between T. gondii nor BVDV-seropositivity and abortions. Typical protozoal histopathologic findings (necrotizing non suppurative encephalitis, meningitis, myocarditis, hepatitis, among others) were observed in all foetuses. Neospora caninum was immunolabelled by immunohistochemistry in several tissues from two foetuses, and infection was also confirmed in the three foetuses by serology and/or DNA detection. No other abortifacient agent was detected in the foetuses. Their dams showed high N. caninum antibody titres (≥ 6400). Serologic evidence and epidemiological data recorded suggested a point-source of N. caninum infection before the occurrence of the outbreak, probably related with contaminated feedstuff with oocysts. Moreover, the intensive production system with a high stocking rate could be also considered a factor which might have increased the risk of horizontal N. caninum infection in this herd.EEA BalcarceFil: Soler, Juan Pablo. Servicio Veterinario CERVUS; Argentina.Fil: Moré, Gastón. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Laboratorio de Inmunoparasitología; Argentina.Fil: Moré, Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Urtizbiría, Facundo Nahuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Hecker, Yanina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Cirone, Karina Mariela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Cirone, Karina Mariela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Scioli, María Valeria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Paolicchi, Fernando Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Paolicchi, Fernando Alberto. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Fiorentino, María Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Fiorentino, María Andrea. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Louge Uriarte, Enrique Leopoldo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Cantón, Germán José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Verna, Andrea Elizabeth. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Verna, Andrea Elizabeth. Consejo Nacional de Investigaciones Científicas Y Técnicas; Argentina.Fil: Morrell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Moore, Dadin Prando. Consejo Nacional de Investigaciones Científicas Y Técnicas; Argentina.Fil: Moore, Dadin Prando. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina

Epidemic abortions due to Neospora caninum infection in farmed red deer (Cervus elaphus)

This study describes for the first time an abortion outbreak caused by Neospora caninum in farmed red deer. During a 5-year period, farmed hinds, naturally mated, were regularly ultrasound monitored to detect reproductive losses over their gestation. During the 4 years previous to the outbreak, abortion rates ranged from 4.7 to 8.6% (average 6.5%), and serology for indirect diagnosis of neosporosis and toxoplasmosis was performed. At the fifth year, the abortion rate increased to 25.3%. During this outbreak, three aborted foetuses and their placentas were recovered and submitted to laboratory for etiological diagnosis. Blood samples were collected from the 81 hinds at the end of the gestational period and the seropositivity rate for N. caninum, Toxoplasma gondii, Brucella abortus, bovine viral diarrhoea virus and bovine alphaherpesvirus type 1 was 66.7%, 67.9%, 0.0%, 8.6% and 0.0%, respectively. Neospora caninum-seropositive hinds (OR = 5.7, P = 0.0271) and hinds with high antibody titres to N. caninum (OR = 7.4, P = 0.0130) were more likely to abort than seronegative hinds. In addition, N. caninum seropositivity rate in the aborted hinds was higher (OR = 5.4, P = 0.033) than the non-aborted hinds. No association was found between T. gondii nor BVDV-seropositivity and abortions. Typical protozoal histopathologic findings (necrotizing non suppurative encephalitis, meningitis, myocarditis, hepatitis, among others) were observed in all foetuses. Neospora caninum was immunolabelled by immunohistochemistry in several tissues from two foetuses, and infection was also confirmed in the three foetuses by serology and/or DNA detection. No other abortifacient agent was detected in the foetuses. Their dams showed high N. caninum antibody titres (≥ 6400). Serologic evidence and epidemiological data recorded suggested a point-source of N. caninum infection before the occurrence of the outbreak, probably related with contaminated feedstuff with oocysts. Moreover, the intensive production system with a high stocking rate could be also considered a factor which might have increased the risk of horizontal N. caninum infection in this herd.Fil: Soler, Juan Pablo. Cervus Veterinary Services; ArgentinaFil: Moré, Gastón Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Epizootiología y Salud Pública. Laboratorio de Inmunoparasitología; ArgentinaFil: Urtizbiría, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; ArgentinaFil: Hecker, Yanina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Cirone, Karina Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Scioli, Maria Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; ArgentinaFil: Paolicchi, Fernando Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Fiorentino, Maria Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Louge Uriarte, Enrique Leopoldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; ArgentinaFil: Canton, German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; ArgentinaFil: Verna, Andrea Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; ArgentinaFil: Morrell, Eleonora Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; ArgentinaFil: Moore, Dadin Prando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentin