Overconfidence and excess entry: a comparison between students and managers

Overconfidence can lead to excessive business entry. Here we replicate the pioneer experiment finding this nexus (Camerer and Lovallo 1999) and extend it in two major directions: (1) to consider managers as well as student subjects and (2) to explicitly take into account selected characteristics of the manager subjects. We find that managers are more prone to the nexus overconfidence-excess entry than students are. In particular, we find that left-handed, married, and emotionally aroused managers are more prone to excess entry.excess business entry, overconfidence, unrealistic optimism

BUSCA, RECUPERAÇÃO E VISUALIZAÇÃO DE RECURSOS ACADÊMICOS DISTRIBUÍDOS

Universities are reference when the subject is research and innovation. So much research creates a lot of related material (papers and videos for example), mostly this material is not shared with the community (of any nature: academic, scientific or public) because there is not a means with easy access and use. Don’t just researches create academic resources, the environment of a university by itself offer a wide range of activities that create academic resources: classes, scientific initiations, symposia, congress and others. The biggest problem of this scenario is that such a wealth of subjects doesn’t have any value when they are saved. As every university has a good IT infrastructure, the hosting and providing of such resources on Internet is trivial, the problem is that should know where the resources are to get them. This work pretends to take place in this context, allow the search of such resources in a transparent way to the final use

El pelícano blanco americano (pelecanus erythrorhynchus) en colombia, con comentarios sobre los efectos de los huracanes en el caribe

Presentamos un registro fotográfico del Pelicano Blanco Americano (Pelecanus erythrorhynchus) en un manglar de la isla de San Andrés, en el Caribe colombiano, con lo cual se confirma la presencia de esta especie en Colombia. Adicionalmente discutimos el posible efecto de los huracanes del Caribe en la dispersión de esta especie y los efectos que estas catástrofes naturales pueden tener en la conservación de la avifauna del Archipiélago de San Andrés y Providencia

Sentinel-1 Satellite Data as a Tool for Monitoring Inundation Areas near Urban Areas in the Mexican Tropical Wet

This work shows advances in the field of water body monitoring with radar images. Particularly, a monitoring procedure is developed to define the extension and frequency of inundation for continental waters of the Grijalva-Usumacinta basin, in the state of Tabasco, Mexico. This is a region located in the Mexican tropical wet and under its meteorological conditions, radar technology can be used to characterize monthly inundation frequency. The identification of water bodies were obtained by processing images at a monthly intervals captured by Sentinel-1A during 2015 having kappa indices and overall accuracy higher than 0.9. The chapter describes the seasonal variability of these water bodies, and at the same time, the relationship with human settlements located in their neighborhood. To do this, a proximity analysis was carried out to emphasize the importance of spatial-temporal studies of superficial water bodies, linked to an urban and a rural area. This information is useful to investigate changes in the ecosystem, as well as risks to human settlements, and as a contribution for a comprehensive management of hydric resources

Contribution of each leg in the static postural stability of unilateral transtibial amputees, a study with Information Theory

Introduction: Transtibial amputees tend to isolate themselves because they lack confidence in performing daily tasks; rehabilitation processes such as the use of prostheses are carried out for their social reintegration, where postural stability must be ensured, and activities allowed in diverse contexts. Objective: Verify the contribution of each leg and direction (anterior/posterior and medial/lateral) of the center of pressure (CoP) in the static postural stability of unilateral transtibial amputees due to landmines using information theory. Methodology: A quantitative experimental design was applied to examine the displacement and velocity of the CoP using infometric measurements in nine transtibial amputees, and the non-parametric U Mann-Whitney test was applied to recognize statistically notable differences (p <0.05) between each leg. Results: There are statistically notable differences between the legs in the variables of displacement and velocity. Each leg contributes differently to the control of the static bipedal posture, and their behavior in the directions of movement of the CoP differs from each other, but they work together to generate compensation strategies that allow maintaining stability.  Conclusions: The use of information theory made it possible to evaluate stability objectively, without specifying the kind of relationship between this and the input variables, which favored the recognition of the CoP shift as its best discriminant in comparison with velocity. Transtibial amputees control static bipedal posture with the non-amputated leg to compensate for the loss of lower leg afferents and efferents due to the amputation. The results demonstrate the suitability of using information theory in the evaluation of lateralized postural control in pathological conditions.Introducción: Los amputados transtibiales tienden a aislarse porque carecen de confianza al ejecutar tareas cotidianas, para su reintegración social se efectúan procesos de rehabilitación como el uso de prótesis, donde se asegura estabilidad postural para realizar diversas actividades. Objetivo: Verificar la contribución de cada pierna y cada dirección (antero-posterior, medio-lateral) del Centro de Presión (CoP) en la estabilidad estática postural de amputados transtibiales. Metodología: Se realizó un estudio observacional en nueve amputados transtibiales unilaterales para examinar el desplazamiento y la velocidad del CoP usando medidas infométricas, y se utilizó el test de U Mann-Whitney(p<0.05) para identificar diferencias entre cada pierna. Resultados: Cada pierna contribuye de diferente manera en el control de la postura bípeda estática y su comportamiento en las direcciones de movimiento del CoP difieren entre sí; pero trabajan en conjunto para generar estrategias de compensación para mantener la estabilidad. Conclusiones: La teoría de la información (TI) de Shannon permitió evaluar de forma objetiva la estabilidad, sin precisar la clase de relación existente entre las variables, lo que favoreció el reconocimiento del desplazamiento del CoP como discriminante de la estabilidad. Los amputados transtibiales controlan la postura bípeda estática con la pierna no amputada para compensar la pérdida de los aferentes y eferentes debido a la amputación. Los resultados demuestran la idoneidad de utilizar TI en la evaluación del control postural lateralizado en condiciones patológicas. La investigación presente aporta en la comprensión de la actividad postural para contribuir en el proceso de rehabilitación física de los amputados

Aporte de cada pierna en la estabilidad estática postural de amputados transtibiales unilaterales, estudio con teoría de la información

Introducción: Los amputados transtibiales tienden a aislarse porque carecen de confianza al ejecutar tareas cotidianas, para su reintegración social se efectúan procesos de rehabilitación como el uso de prótesis, donde se asegura estabilidad postural para realizar diversas actividades. Objetivo: Verificar la contribución de cada pierna y cada dirección (antero-posterior, medio-lateral) del Centro de Presión (CoP) en la estabilidad estática postural de amputados transtibiales. Metodología: Se realizó un estudio observacional en nueve amputados transtibiales unilaterales para examinar el desplazamiento y la velocidad del CoP usando medidas infométricas, y se utilizó el test de U Mann-Whitney(p<0.05) para identificar diferencias entre cada pierna. Resultados: Cada pierna contribuye de diferente manera en el control de la postura bípeda estática y su comportamiento en las direcciones de movimiento del CoP difieren entre sí; pero trabajan en conjunto para generar estrategias de compensación para mantener la estabilidad. Conclusiones: La teoría de la información (TI) de Shannon permitió evaluar de forma objetiva la estabilidad, sin precisar la clase de relación existente entre las variables, lo que favoreció el reconocimiento del desplazamiento del CoP como discriminante de la estabilidad. Los amputados transtibiales controlan la postura bípeda estática con la pierna no amputada para compensar la pérdida de los aferentes y eferentes debido a la amputación. Los resultados demuestran la idoneidad de utilizar TI en la evaluación del control postural lateralizado en condiciones patológicas. La investigación presente aporta en la comprensión de la actividad postural para contribuir en el proceso de rehabilitación física de los amputados.Introduction: Transtibial amputees tend to isolate themselves because they lack confidence in performing daily tasks; rehabilitation processes such as the use of prostheses are carried out for their social reintegration, where postural stability must be ensured, and activities allowed in diverse contexts. Objective: Verify the contribution of each leg and direction (anterior/posterior and medial/lateral) of the center of pressure (CoP) in the static postural stability of unilateral transtibial amputees due to landmines using information theory. Methodology: A quantitative experimental design was applied to examine the displacement and velocity of the CoP using infometric measurements in nine transtibial amputees, and the non-parametric U Mann-Whitney test was applied to recognize statistically notable differences (p <0.05) between each leg. Results: There are statistically notable differences between the legs in the variables of displacement and velocity. Each leg contributes differently to the control of the static bipedal posture, and their behavior in the directions of movement of the CoP differs from each other, but they work together to generate compensation strategies that allow maintaining stability.  Conclusions: The use of information theory made it possible to evaluate stability objectively, without specifying the kind of relationship between this and the input variables, which favored the recognition of the CoP shift as its best discriminant in comparison with velocity. Transtibial amputees control static bipedal posture with the non-amputated leg to compensate for the loss of lower leg afferents and efferents due to the amputation. The results demonstrate the suitability of using information theory in the evaluation of lateralized postural control in pathological conditions

Two-dimensional multiscale entropy analysis: applications to image texture evaluation

Complexity measures, defined as measures of irregularity over time scales, are the subject of a growing number of studies as the information they reveal can find utility in a large field of applications. One of the most popular complexity measures is the multiscale entropy. Nevertheless, more and more algorithms dedicated to complexity analyses are proposed to improve the existing ones. However, such measures are available only for one-dimensional time series. For bidimensional data (images), no equivalent algorithm has been proposed to analyze irregularity over spatial scales. We herein introduce a new framework that extends the one-dimensional multiscale entropy (MSE1D) to the bidimensional case (MSE2D). Moreover, a variant of MSE2D is also ModMSE2D). The two new algorithms are tested as new texture analysis frameworks. They are applied to simulated and real data. Our results show that, compared with other existing texture analysis algorithms, MSE2D and ModMSE2D are suitable and powerful tools for image analysis and classification according to their texture patterns. While MSE2D is computationally faster than ModMSE2D, ModMSE2D is more robust to small image sizes. The two methods present interesting performances, and can be as useful as their unidimensional versions in two-dimensional applications