DISPOSITION EFFECT AMONG BRAZILIAN EQUITY FUND MANAGERS

The disposition effect predicts that investors tend to sell winning stocks too soon and ride losing stocks too long. Despite the wide range of research evidence about this issue, the reasons that lead investors to act this way are still subject to much controversy between rational and behavioral explanations. In this article, the main goal was to test two competing behavioral motivations to justify the disposition effect: prospect theory and mean reversion bias. To achieve it, an analysis of monthly transactions for a sample of 51 Brazilian equity funds from 2002 to 2008 was conducted and regression models with qualitative dependent variables were estimated in order to set the probability of a manager to realize a capital gain or loss as a function of the stock return. The results brought evidence that prospect theory seems to guide the decision-making process of the managers, but the hypothesis that the disposition effect is due to mean reversion bias could not be confirmed

Morphologicalcharacteristicsofthe atibaiariverfloodplain, caMpinasand JaguariunaMuncipalities, sp, brazi

As planícies aluvionares são ecossistemas situados próximos ao nível de base de cursos de água, onde vários ambientes se inter-relacionam. Elas são consideradas áreas de descarga do escoamento básico de rios, e resultados de processos de assoreamento de sedimentos e erosão do rio ao longo do Quaternário, e compreendem um sistema complexo e dinâmico, seja em relação às suas características físicas como biológicas. A ocupação urbana e periurbana nestes locais, classificam-nas como áreas de risco hidrológico, uma vez que cheias sazonais ou chuvas extremas impactam a comunidade residente. A planície do rio Atibaia é uma extensa área limítrofe com os municípios de Campinas, Jaguariúna e Paulínia situada na transição entre a Depressão Periférica e o Planalto Atlântico. Trata-se de uma área de cerca de 34 km2, onde o rio Atibaia corre encaixado nas fraturas e falhas do embasamento cristalino. A planície forma uma pequena bacia sedimentar, decorrente do afunilamento da calha por diabásios a jusante, e a montante por rochas gnáissicas. Ela apresenta dois terraços representativos de fases de formação da planície, paleomeandros e paleocanais, antigas barras de pontal e diques marginais. Pequenas elevações são encontradas ao longo das margens do rio e migrações de meandros recentes de sentido noroeste e sudeste foram registradas, uma vez que o rio se encontra meandrante nesta parte de seu curso. Os campos úmidos e bacias de decantação representam área com níveis aflorantes do aquífero freático, e áreas de baixios (na região mais baixa da planície) onde a água se acumula e escoa15Alluvial plain is a complex and dynamic system situated near the base level of watercourses and is the result of sedimentation and erosion processes. It is an area of hydrological risk for urban and peri-urban occupation, due to seasonal floods. The Atibaia river plain is an extensive border area (approximately 34 km2) within the municipalities of Campinas, Jaguariúna and Paulínia. It is located in the transition between the Peripheral Depression and the Atlantic Plateau. The plain forms a small sedimentary basin, formed above the sedimentary rocks of Itarare Subgroup, due the tapering of the river channel by diabase rocks downstream, and gneiss rocks upstream. It exhibits two terraces with paleomeanders and paleo-channels, old point bars and levees. Small elevations are present, and recent NW and SE migrations of meanders were recorded. Wetlands and swamps are areas where the groundwater reaches the surface, accumulates and flows slowly to the rive

Evaluation of hemodynamic effects of xenon in dogs undergoing hemorrhagic shock

OBJECTIVES: The anesthetic gas xenon is reported to preserve hemodynamic stability during general anesthesia. However, the effects of the gas during shock are unclear. The objective of this study was to evaluate the effect of Xe on hemodynamic stability and tissue perfusion in a canine model of hemorrhagic shock. METHOD: Twenty-six dogs, mechanically ventilated with a fraction of inspired oxygen of 21% and anesthetized with etomidate and vecuronium, were randomized into Xenon (Xe; n = 13) or Control (C; n = 13) groups. Following hemodynamic monitoring, a pressure-driven shock was induced to reach an arterial pressure of 40 mmHg. Hemodynamic data and blood samples were collected prior to bleeding, immediately after bleeding and 5, 20 and 40 minutes following shock. The Xe group was treated with 79% Xe diluted in ambient air, inhaled for 20 minutes after shock. RESULT: The mean bleeding volume was 44 mL.kg-1 in the C group and 40 mL.kg-1 in the Xe group. Hemorrhage promoted a decrease in both the cardiac index (p<0.001) and mean arterial pressure (p<0.001). These changes were associated with an increase in lactate levels and worsening of oxygen transport variables in both groups (p<0.05). Inhalation of xenon did not cause further worsening of hemodynamics or tissue perfusion markers. CONCLUSIONS: Xenon did not alter hemodynamic stability or tissue perfusion in an experimentally controlled hemorrhagic shock model. However, further studies are necessary to validate this drug in other contexts

Hipoxemia después de la revascularización miocárdica: análisis de los factores de riesgo

JUSTIFICATIVA E OBJETIVOS: Hipoxemia grave é uma complicação freqüente no pós-operatório imediato de revascularização do miocárdio (RM), promovendo aumento da duração da ventilação mecânica, da incidência de infecções pulmonares, dos custos e da mortalidade. O objetivo desse estudo foi identificar fatores preditivos de hipoxemia grave em pacientes submetidos à RM. MÉTODO: Foram estudados 481 pacientes adultos submetidos à RM eletiva entre outubro de 2003 e março de 2004. Considerou-se hipoxemia grave uma relação PaO2/FiO2 < 150 na admissão à UTI. A análise estatística foi realizada por meio de teste de Qui-quadrado, t de Student ou Wilcoxon, seguida de análise multivariada por meio de regressão logística (RL) para variáveis com valor p < 0,25 na análise univariada. Considerou-se valor de p > 0,2 para exclusão da variável do modelo de RL e p < 0,1 como sendo significativo. RESULTADOS: O tempo para extubação dos pacientes com hipoxemia grave foi maior que nos outros pacientes (p < 0,001). Na análise multivariada, as variáveis idade (p = 0,081), peso (p = 0,001), necessidade de CEC prolongada (p = 0,033) e disfunção ventricular esquerda (p = 0,082) foram identificadas como preditores independentes para hipoxemia grave. CONCLUSÕES: Pacientes com idade e peso elevados, disfunção ventricular esquerda e necessidade de CEC apresentaram risco aumentado para hipoxemia grave após RM. Nesses pacientes, o uso de estratégias ventilatórias perioperatória com pressões positivas expiratórias mais elevadas e manobra de recrutamento alveolar devem ser consideradas tendo como objetivo a prevenção da disfunção pulmonar pós-operatória.BACKGROUND AND OBJECTIVES: Severe hypoxemia is complication frequently seen in the immediate postoperative period of myocardial revascularization (MR), increasing the duration of mechanical ventilation, the incidence of pulmonary infections, hospital costs, and mortality. The objective of this study was to identify predictive factors of severe hypoxemia in patients undergoing MR. METHODS: Four-hundred and eighty-one adult patients undergoing elective MR between October 2003 and March 2004 were enrolled in this study. Severe hypoxemia was defined as PaO2/FiO2 < 150 upon admission to the ICU. The Chi-square test, Student's t or Wilcoxon test, followed by multivariate analysis and logistic regression (LR) for parameters with p < 0.25 in the univariate analysis, were used for the statistical analysis. A p > 0.2 was required to exclude the parameter from the LR model, and a p < 0.1 was considered significant. RESULTS: Time for extubation was greater in patients with severe hypoxemia (p < 0.001). Multivariate analysis identified age (p = 0.081), weight (p = 0.001), need of prolonged CBP (p = 0.033), and left ventricular dysfunction (p = 0.082) as independent predictors of severe hypoxemia. CONCLUSIONS: Older and overweighted patients, those with left ventricular dysfunction, and those who needed CPB presented an increased risk of severe hypoxemia after MR. In those patients, the use of perioperative ventilatory strategies, with elevated positive expiratory pressures and alveolar recruitment maneuver should be considered to prevent postoperative pulmonary dysfunction.JUSTIFICATIVA Y OBJETIVOS: La hipoxemia grave es una complicación frecuente en el postoperatorio inmediato de revascularización del miocardio (RM), promoviendo un aumento de la duración de la ventilación mecánica, de la incidencia de infecciones pulmonares, de los costos y de la mortalidad. El objetivo de este estudio fue identificar factores de predicción de hipoxemia grave en pacientes sometidos a la RM. MÉTODO: Se estudiaron 481 pacientes adultos sometidos a la RM electiva entre octubre de 2003 y marzo de 2004. Se tomó en consideración hipoxemia grave en una relación PaO2/FiO2 < 150 en la admisión a la UCI. El análisis estadístico fue realizada a través de test de cui cuadrado, t de Student o Wilcoxon, seguido de análisis multivariado a través de regresión logística (RL) para variables con valor p < 0,25 en el análisis univariado. Se tuvo en cuenta el valor de p > 0,2 para la exclusión de la variable del modelo de RL y p < 0,1 como siendo significativo. RESULTADOS: El tiempo para la extubación de los pacientes con hipoxemia grave fue mayor que en los otros pacientes (p < 0,001). En el análisis multivariado, las variables edad (p = 0,081), peso (p = 0,001), necesidad de CEC prolongada (p = 0,033) y disfunción ventricular izquierda (p = 0,082) fueron identificadas como de predicción independientes para hipoxemia grave. CONCLUSIONES: Pacientes con edad y peso elevados, disfunción ventricular izquierda y necesidad de CEC presentaron un riesgo aumentado para hipoxemia grave después de la RM. NE estos pacientes, el uso de estrategias ventilatorias perioperatoria con presiones positivas de expiración más elevadas y la maniobra de reclutamiento alveolar deben ser consideradas teniendo en cuenta la prevención de la disfunción pulmonar postoperatoria

Early warming stress on rainbow trout juveniles impairs male reproduction but contrastingly elicits intergenerational thermotolerance

Abstract The exposure of adult fish to warm or high temperatures is known to impair reproduction, yet the long-term reproductive impacts for treatments at early life are not well clarified. This study aimed to evaluate the effects of warm temperature (WT) during juvenile stage on gonad maturation, gamete quality, and offspring thermotolerance in rainbow trout. While the comparison of basic reproductive parameters in WT females did not reveal any kind of impairment, many WT males showed an atrophied, undeveloped gonad, or a smaller testis with lower milt volume; sperm quality parameters in WT males and deformity rates in the respective progeny were also highly affected. However, despite of such negative effects, many of the remaining progeny presented better rates of survival and growth when exposed to the same conditions as those of parental fish (WT), suggesting that thermal stress in parr stage males elicited intergenerational thermotolerance after a single generation. The present results support that prolonged warming stress during early life stages can adversely affect key reproductive aspects, but contrastingly increase offspring performance at upper thermal ranges. These findings have implications on the capacity of fish to adapt and to cope with global warming

Control of Hysterothylacium sp . (Nematoda: Anisakidae) in juvenile pirarucu ( Arapaima gigas ) by the oral application of essential oil of Piper aduncum

The nematode Hysterothylacium sp. (Nematoda, Anisakidae) may cause significant economic losses in fish production. In order to control the nematode larvae in juvenile pirarucu (52 ± 3.2 g), the efficacy of essential oil (EO) of Piper aduncum when added to feed was evaluated. Chemical analysis of the EO composition had been performed previously, showing that 92% of the substance was dillapiole. After the palatability test, the efficacy of the EO was evaluated (0, 32, 48, 56, and 64 mL/kg) at 7 and 15 days, based on the blood parameters and the parasite load of the fish. The results showed significant differences for hematocrit and corpuscular constants at 7 days and for total proteins at 15 days between the treatment groups and the control group (without EO). The parasitic indices showed a prevalence of 100% for stage L3 larva of the nematode Hysterothylacium sp. At 7 and 15 days, the values of average intensity, average abundance, and intensity of parasites decreased with increasing EO concentration, and at 15 days, these were significantly lower between the treatment group and the control group, with an efficacy of 76.21% for 64 mL/kg. Thus, the EO of P. aduncum demonstrates anthelmintic potential in the control of nematode larvae in pirarucu without affecting fish homeostasis. © 2018 Elsevier B.V