The Multidimensional Study of Viral Campaigns as Branching Processes

Viral campaigns on the Internet may follow variety of models, depending on the content, incentives, personal attitudes of sender and recipient to the content and other factors. Due to the fact that the knowledge of the campaign specifics is essential for the campaign managers, researchers are constantly evaluating models and real-world data. The goal of this article is to present the new knowledge obtained from studying two viral campaigns that took place in a virtual world which followed the branching process. The results show that it is possible to reduce the time needed to estimate the model parameters of the campaign and, moreover, some important aspects of time-generations relationship are presented.Comment: In proceedings of the 4th International Conference on Social Informatics, SocInfo 201

Is CHF triggered by the vapor recoil effect?

This paper deals with the triggering mechanism of the boiling crisis, a transition from nucleate to film boiling. We observe the boiling crisis in pool saturated boiling experimentally at nearly critical pressure to take advantage of the slowness of the bubble growth and of the smallness of the Critical Heat Flux (CHF) that defines the transition point. Such experiments require the reduced gravity conditions. Close to the CHF, the slow growth of the individual dry spots and their subsequent fusion on the transparent heater are observed through the latter. As discussed in the paper, these observations are consistent with numerical results obtained with the vapor recoil model of the boiling crisis

The Shigella flexneri OmpA amino acid residues 188EVQ190 are essential for the interaction with the virulence factor PhoN2

Shigella flexneri is an intracellular pathogen that deploys an arsenal of virulence factors promoting host cell invasion, intracellular multiplication and intra- and inter-cellular dissemination. We have previously reported that the interaction between apyrase (PhoN2), a periplasmic ATP-diphosphohydrolase, and the C-terminal domain of the outer membrane (OM) protein OmpA is likely required for proper IcsA exposition at the old bacterial pole and thus for full virulence expression of Shigella flexneri (Scribano et al., 2014). OmpA, that is the major OM protein of Gram-negative bacteria, is a multifaceted protein that plays many different roles both in the OM structural integrity and in the virulence of several pathogens. Here, by using yeast two-hybrid technology and by constructing an in silico 3D model of OmpA from S. flexneri 5a strain M90T, we observed that the OmpA residues 188EVQ190 are likely essential for PhoN2-OmpA interaction. The 188EVQ190 amino acids are located within a flexible region of the OmpA protein that could represent a scaffold for protein-protein interaction

Tangible and intangible rewards in service industries: problems and prospects

Willingness and readiness of people to do their jobs are among the key factors of a successful enterprise. In XXI century intellectual human labour is gaining unprecedented value and is being developed actively. The demand for intellectual labour calls forth an increasing number of jobs and professions that require an extensive preparation, a large number of working places, high level of integration of joint human efforts, growth of social welfare. These trends are becoming ever more pervasive and are spreading widely in service industries, and that explains the rapid development of the latter when compared to the traditional areas of human activity. In its turn, it heightens the need for staff in service companies, supported by significant personnel turnover and a certain shortage of skilled professionals. These circumstances determine the need for developing a new concept of fostering staff motivation at the enterprises in the sphere of services. In order to reach the stated purpose while conducting our research into tourism and hospitality industry, as well as retail chains, we have examined the problems that arise in the process of staff motivation, and studied the foreign practice of motivating staff in hotels. The obtained analysis results enabled us to work out practical recommendations on improvement of the mechanism of tangible and intangible rewards in service companies, which are based on external and internal motivational factors. Additional attention in the article is paid to the statement that financial incentives should be based on key performance indicators (KPI). We give a detailed consideration to the classification of internal motivation incentives of the staff according to the terms of their realization, and give a schematic representation of the performance dynamics of the internal motivation model in service businesse