Cloud Computing (CC) is a recent technology in the Information and Communication Technology (ICT) field. It provides an on-demand access to the shared pool of resources via virtualization. Large enterprises move toward CC due to its flexibility and scalability driven from its elastic pay-per-use model. To provide ensured efficient performance to users, tasks should be efficiently mapped to available resources. Therefore, Task Scheduling (TS) is significant issue in the CC technology. TS is a NP-complete optimization problem, so a deep investigation of different metaheuristic and heuristic TS algorithms is presented here. Particle Swarm Optimization (PSO) and Genetic Algorithms (GA) as metaheuristic algorithms are implemented and their performance have been compared to heuristic techniques (First Come First Serve (FCFS) and Shortest Job First (SJF)) on symmetric and asymmetric environment. The cloud service providers and users have different performance requirements. Six performance metrics including makespan, flow time, response time, resource utilization, throughput time and degree of imbalance have been measured. For asymmetric environment, real environment, metaheuristic TS algorithms surpassed the heuristic methods.

Background: Alopecia areata (AA) is non-scarring hair loss resulting from an autoimmune disorder. Severity varies from patchy hair loss that often spontaneously resolves to severe and chronic cases that can progress to total loss of scalp and body hair. Aim of the work: To compare the efficacy of topical calcipotriol versus oral vitamin D in alopecia areata. Patient and Methods: Fifty patients having localized alopecia (<5 patches and <40% scalp involvement) were treated with topical calcipotriol 0.005% twice daily for 3 months (group 1) and oral vitamin D daily for 3 months (group 2). All cases were assessed by grading the degree of improvement of alopecia and dermoscopic evaluation. Estimation of serum levels of 25-hydroxy vitamin D in all patients before the treatment. Results: There was statistically significant difference with p-value < 0.05 between two study groups regarding to degree of improvement. Dermoscopic findings that explain signs of activity were decreased, and signs of improvement were appeared after 3rd months of treatment. In topical calcipotriol group terminal hair was more than oral vitamin D group, in which signs of activity was still present in some cases. Conclusion: In conclusion, topical calcipotriol (68% improvement) was better than oral vitamin D in the treatment of mild and moderate alopecia areata. There is no releation between serum vitamin D and efficacy of treatment. However, further studies on larger scales are required to identify the vitamin D receptor deficiency in alopecia areata.