Four age groups of Fischer 344 rats (6-, 12-, 18-, and 24-months of age) were compared on a battery of reflexive and locomotor tasks. The simple reflexive tasks such as placing, hopping, negative geotaxis and surface and mid-air righting showed little or no change as a function of age. In contrast, tasks requiring more coordinated control of motor and reflexive responses such as suspension from a horizontal wire, descent of a wire mesh pole, traversal of an elevated platform and rotorod performance showed significant declines with age, with some declines noticeable early in the lifespan. When these results are compared with the results of tasks conducted with infant rats, it is noted that the reflexive and motor skills that emerge early in development are the least affected by the aging process. This observation suggests a first-in, last-out sequence for reflexive and motor behaviors.

Este artigo aborda as finanças comportamentais, uma das inovações mais importantes e controversas em finanças, que confrontam o paradigma tradicionalmente aceito, baseado na moderna teoria financeira. Inicialmente realiza-se uma síntese de potenciais problemas de tomada de decisão, exemplificando-se alguns aspectos não racionais que constituem importantes paradoxos em finanças. Após uma discussão da teoria de prospecto, replicam-se numa amostra brasileira os experimentos seminais de Kahneman e Tversky. São discutidas diversas situações que violam premissas da teoria da utilidade esperada, base da teoria moderna de finanças. Os resultados empíricos mostram que se mantêm as evidências de diversos vieses de percepção em decisões, independentemente de aspectos relacionados com a evolução do mercado e com a cultura ou nacionalidade dos indivíduos. O distanciamento entre a teoria moderna de finanças e a prática em decisões financeiras sugere a abordagem das finanças comportamentais como uma alternativa para explicar o comportamento dos agentes econômicos. PALAVRAS-CHAVE Finanças comportamentais, comportamento do investidor, teoria moderna de finanças, teoria da utilidade esperada, vieses cognitivos. Herbert Kimura Universidade Presbiteriana Mackenzie Leonardo Fernando Cruz Basso Universidade Presbiteriana Mackenzie Elizabeth Krauter FEA-USP ABSTRACT This study discusses the Behavioral Finance, one of the most important and controversial innovations in finance

Short-term and spatial memory were studied in Fischer 344 rats ranging in age from 6 to 26 months of age. Spatial memory, as measured by performance in an 8-armed radial maze, declined gradually with age. In contrast, short-term memory, as measured by retention of previous choices in the spatial maze over short intervals and performance on a modified form of Konorski's discriminated delayed response task, did not decline differentially as a function of age. These findings may be comparable to those obtained in the aged human, who also show marked deficits in spatial memory and little change in primary memory under appropriate test conditions.

The Brazilian model of corporate governance is characterized by a highly concentrated ownership structure, which usually culminates in an overlap between ownership and management. According to the literature, the accumulation of shares by the controller(s) can affect corporate performance due to both the alignment (or incentive) effect and the entrenchment effect. At first, the presence of large shareholders is associated with benefits for an organization because it increases the effectiveness of management monitoring. However, very high levels of ownership concentration can allow controllers to dominate the corporation's decision-making process, which could result in the expropriation of wealth from minority shareholders. The relevance of the ownership structure as an internal mechanism of corporate governance motivates the present study. This article aims to test whether ownership and control concentration influences corporate market value. An unbalanced panel was used for the period from 2001 to 2010, composed of 237 Brazilian non-financial publicly traded companies, totaling 1,199 observations. Dynamic regression models were used, estimated by the System Generalized Method of Moments (Sys-GMM), to mitigate possible sources of endogeneity, such as the omission of variables, the feedback effect, and the simultaneity. A quadratic relationship was found between cash flow rights of the largest shareholder and firm market value. Moreover, the results indicate that the corrected market value of the total shares held by the largest shareholder captured the incentive effect, while voting rights concentration captured the entrenchment effect.

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