A robot swarm assisting a human fire-fighter

Emergencies in industrial warehouses are a major concern for fire-fighters. The large dimensions, together with the development of dense smoke that drastically reduces visibility, represent major challenges. The GUARDIANS robot swarm is designed to assist fire-fighters in searching a large warehouse. In this paper we discuss the technology developed for a swarm of robots assisting fire-fighters. We explain the swarming algorithms that provide the functionality by which the robots react to and follow humans while no communication is required. Next we discuss the wireless communication system, which is a so-called mobile ad-hoc network. The communication network provides also the means to locate the robots and humans. Thus, the robot swarm is able to provide guidance information to the humans. Together with the fire-fighters we explored how the robot swarm should feed information back to the human fire-fighter. We have designed and experimented with interfaces for presenting swarm-based information to human beings

Effects of silver nanoparticle on lactate dehydrogenase activity and histological changes of heart tissue in male wistar rats

Background & Objective: The silver nanoparticles are important in many applications of nanoparticles on human health . The toxicity of silver nanoparticles are not well documented yet. The aim of this study was to investigate the effect of silver nanoparticles on lactate dehydrogenase activity and histological changes in heart tissue.   Materials &Methods: In this study, 40 adult male wistar rats of 220±20gr were divided in to five groups including control and four experimental groups. The latter groups were injected intraperitoneally spherical nano silver particles of 50, 100, 200 and 400 ppm respectively for five consecutive days. Then three, eight and twelve days after the last injection, blood samples were collected and lactate dehydrogenase (LDH) activity was assayed . Also, tissue samples from the heart muscle were prepared and studied after staining with Hematoxiline-Eosine. Data of LDH activity was analyzed by One way- ANOVA- test and P-value of ≤ 0.05 were considered as significant.   Results : The result showed that different concentrations of silver nanoparticles have no significant effect on the lactate dehydrogenase (p=0.192) . T he histological study of the tissue after exposure to 400 ppm concentration of silver nanoparticles showed the start of primary apoptosis in heart tissue.   Conclusion: The LDH activity was not changed significantly after exposure to different concentration of silver nanoparticles, which shows the safety of these particles on LDH activity

The Relationship between Classroom Environment and EFL Learners' Academic Self-Efficacy

The present study sought to examine the relationship between classroom environment and English as a Foreign Language (EFL) learners' academic self-efficacy. To this end, a sample of 200 advanced EFL learners (146 females and 54 males) completed the What is Happening In This Class? (WIHIC) which consists of seven scales including Student Cohesiveness, Teacher Support, Involvement, Investigation, Task Orientation, Cooperation, and Equity that help to measure classroom learning environment. The Self-Efficacy for Learning Form (SELF-A) was also administered to gauge the participants’ academic self-efficacy. In order to analyze the data, Spearman rank-order correlation was run. The results revealed that there was a significant relationship between EFL learners’ classroom environment and their self-efficacy (rho = .438). The findings reflected that the highest relationship was between task orientation and self-efficacy (rho = .433) followed by the relationship between student cohesiveness and self-efficacy (rho = .353).  However, the lowest relationship was found for the relationship between cooperation and self-efficacy (rho = .199). Overall, the results highlight the relationship between classroom environment and academic self-efficacy