Altruistic behavior and cooperation: The role of intrinsic expectation when reputational information is incomplete.

Altruistic behavior is known to be conditional on the level of altruism of others. However, people often have no information, or incomplete information, about the altruistic reputation of others, for example when the reputation was obtained in a different social or economic context. As a consequence, they have to estimate the other's altruistic intentions. Using an economic game, we showed that without reputational information people have intrinsic expectations about the altruistic behavior of others, which largely explained their own altruistic behavior. This implies that when no information is available, intrinsic expectations can be as powerful a driver of altruistic behavior as actual knowledge about other people's reputation. Two strategies appeared to co-exist in our study population: participants who expected others to be altruistic and acted even more altruistically themselves, while other participants had low expected altruism scores and acted even less altruistically than they expected others to do. We also found evidence that generosity in economic games translates into benefits for other social contexts: a reputation of financial generosity increased the attractiveness of partners in a social cooperative game. This result implies that in situations with incomplete information, the fitness effects of indirect reciprocity are cumulative across different social contexts

The Effects of the Environment and Linear Actuators on Robot Morphologies

The field of evolutionary robotics uses principles of natural evolution to design robots. In this paper, we study the effect of adding a new module inspired by the skeletal muscle to the existing RoboGen framework: the linear actuator. Additionally, we investigate how robots evolved in a plain environment differ from robots evolved in a rough environment. We consider the task of directed locomotion for comparing evolved robot morphologies. The results show that the addition of the linear actuator does not have a significant impact on the performance and morphologies of robots evolved in a plain environment. However, we find significant differences in the morphologies of robots evolved in a plain environment and robots evolved in a rough environment. We find that more complex behavior and morphologies emerge when we change the terrain of the environment

Efficient path sampling on multiple reaction channels

Due to the time scale problem, rare events are not accessible by straight forward molecular dynamics. The presence of multiple reaction channels complicates the problem even further. The feasibility of the standard free energy based methods relies strongly on the success in finding a proper reaction coordinate. This can be very difficult task in high-dimensional complex systems and even more if several distinct reaction channels exist. Moreover, even if a proper reaction coordinate can be found, ergodic sampling will be a challenge. In this article, we discuss the recent advancements of path sampling methods to tackle this problem. We argue why the path sampling methods, via the transition interface sampling technique, is less sensitive to the choice of reaction coordinate. Moreover, we review a new algorithm, parallel path swapping, that can dramatically improve the ergodic sampling of trajectories for the multiple reaction channel systems.Comment: 7 pages, 4 figures. Article submitted for the proceedings of the Conference on Computational Physics, Brussels 200

The correlation between C-reactive protein and toxic granulation of neutrophils in the peripheral blood

Background. During inflammation, the serum concentrations of granulocyte colony-stimulating factor (G-CSF), plasma interleukin-6 (IL-6), and C-reactive protein (CRP) increase. A positive correlation between CRP and the percentages of neutrophils exhibiting toxic granulation during inflammation has been demonstrated, and that the fluctuations of CRP and toxic granulation of neutrophils were similar. Objectives. We studied whether grading of toxic granulated neutrophils can be used as a surrogate marker for infection or inflammation, and also be an easier method than previously described methods. Materials and methods. We graded 357 consecutive peripheral blood slides from patients on whom a full blood count with differential count and CRP level was performed, according to intensity of toxic granulation in the neutrophil population, according to a newly proposed grading system. Results. The CRP range was between 1 and 530.3 mg/l. The results confirm the association between a rise in CRP and progressive intensity of toxic granulation in neutrophils in peripheral blood. Kruskal-Wallis equality of populations rank test showed a statistically significant difference between the graded categories (p=0.0001). The Trend test was also statistically significant (p=0.000). Conclusion. The proposed system can be applied to patients with inflammatory or infectious conditions, where grading of toxic granulation of neutrophils can possibly be used as a surrogate marker to assess infection or inflammation and their response to treatment. It may be of particular use in cases where traditional infectious or inflammatory markers cannot be used, owing to inherent problems associated with the respective conditions