Emergence of world-stock-market network

In the age of globalization, it is natural that the stock market of each country is not independent form the other markets. In this case, collective behavior could be emerged form their dependency together. This article studies the collective behavior of a set of forty influential markets in the world economy with the aim of exploring a global financial structure that could be called world-stock-market network. Towards this end, we analyze the cross-correlation matrix of the indices of these forty markets using Random Matrix Theory (RMT). We find the degree of collective behavior among the markets and the share of each market in their structural formation. This finding together with the results obtained from the same calculation on four stock markets reinforce the idea of a world financial market. Finally, we draw the dendrogram of the cross-correlation matrix to make communities in this abstract global market visible. The dendrogram, drawn by at least thirty percent of correlation, shows that the world financial market comprises three communities each of which includes stock markets with geographical proximity

Absorbing transition in a coevolution model with node and link states in an adaptive network: Network fragmentation transition at criticality

We consider a general model in which there is a coupled dynamics of node states and links states in a network. This coupled dynamics coevolves with dynamical changes of the topology of the network caused by a link rewiring mechanism. Such coevolution model features the interaction of the local dynamics of node and link states with the nonlocal dynamics of link-rewiring in a random network. The coupled dynamics of the states of the nodes and the links produces by itself an absorbing phase transition which is shown to be robust against the link rewiring mechanism. However, the dynamics of the network gives rise to significant physical changes, specially in the limit in which some links do not change state but are always rewired: First a network fragmentation occurs at the critical line of the absorbing transition, and only at this line, so that fragmentation is a manifestation of criticality. Secondly, in the active phase of the absorbing transition, finite-size fluctuations take the system to a single network component consensus phase, while other configurations are possible in the absence of rewiring. In addition, this phase is reached after a survival time that scales linearly with system size, while the survival time scales exponentially with system size when there is no rewiring. A social interpretation of our results contribute to the description of processes of emergence of social fragmentation and polarization

Absorbing phase transition in the coupled dynamics of node and link states in random networks

We present a stochastic dynamics model of coupled evolution for the binary states of nodes and links in a complex network. In the context of opinion formation node states represent two possible opinions and link states a positive or negative relation. Dynamics proceeds via node and link state update towards pairwise satisfactory relations in which nodes in the same state are connected by positive links or nodes in different states are connected by negative links. By a mean-field rate equations analysis and Monte Carlo simulations in random networks we find an absorbing phase transition from a dynamically active phase to an absorbing phase. The transition occurs for a critical value of the relative time scale for node and link state updates. In the absorbing phase the order parameter, measuring global order, approaches exponentially the final frozen configuration. Finite size effects are such that in the absorbing phase the final configuration is reached in a characteristic time that scales logarithmically with system size, while in the active phase, finite-size fluctuation take the system to a frozen configuration in a characteristic time that grows exponentially with system size. There is also a finite-size topological transition associated with group splitting in the network of these final frozen configurations

A Qualitative Investigation into Components of Patient Safety Organizational Culture in the Medical Education Centers: A Medical Errors Management Approach

The patient safety is a subset of organizational culture and is defined as a set of individual and organizational priorities, values, attitudes and behaviors which look for minimizing errors and damages arising from the process of patient treatment. This study seeks to describe the experiences of patients and their companions about the patient safety organizational culture and medical errors management. Methods: This qualitative study was conducted in the health and medical education centers affiliated with Isfahan University of Medical Sciences in 2017. A total of 15 patients and companions receiving health services in medical education centers were selected using purposive sampling and in-depth interviews were conducted with the participants. Conventional qualitative content analysis was used to analyze the data. Results: 186 initial codes, 23 sub-subcategories and 6 main themes were extracted from the data which are as follows: culture of errors acceptance vs. non-acceptance, culture of disclosing vs. hiding errors, psychological and physical consequences and financial burden of medical errors, learning from errors, the culture of patient participation and training, developing the culture of safety and all-inclusive quality improvement. Conclusion: The results of the present study indicate a vast array of culture of nonacceptance vs. acceptance of errors and disclosing vs. hiding errors. Thus, it is imperative for the organization's senior managers to make corrective interventions so as to maintain and promote the culture of learning from errors and patient education and participation in the process of their treatment and ultimately the culture of safety and all-inclusive quality improvement

Iranian EFL Teachers’ Conceptions and Practices of Communicative Language Teaching Curriculum

Enabling learners to communicate both in an inter-personal level and with people of other nations is greatly emphasized in language learning programs. The present study seeks to analyze the conceptions of Iranian teachers after they implemented the new communicative language teaching (CLT) curriculum. To do so, two teachers were asked to record one session of their classes and subsequently participate in semi-structured interviews to elaborate on their rationale of what they did in the classroom. One of the teachers was a male with over 20 years of teaching experience, and the other was a female with almost the same years of teaching experience as the male. The analysis of the data showed wide discrepancies between teachers’ actual activities and the curriculum recommendations. The teachers highlighted their previous schooling as a student as well as contextual realities as factors influencing their teaching. The study highlighted the point that if teachers’ beliefs and the contextual realities are not in tune, teachers filter the curriculum in their own preferred ways leading to divergences from the proposed curriculum. Therefore, the study has clear implications for curriculum developers to consider contextual realities when proposing any innovations. It can also be of use for teachers to be aware of the need to be more cautious when implementing a new curriculum

Adjunctive Local Application of Lidocaine during Scleral Buckling under General Anesthesia

Purpose: To evaluate the effect of local lidocaine application on the incidence of the oculocardiac reflex (OCR) during scleral buckling (SB) for rhegmatogenous retinal detachment (RRD) under general anesthesia. Methods: In a randomized clinical trial, eyes with RRD scheduled for SB under general anesthesia were randomized to adjunctive local application of 1 ml lidocaine 2% versus normal saline to the muscles after conjunctival opening. Surgical stimulation was initiated 5 minutes afterwards. Additionally, 100 mg of lidocaine 2% was added to 50 ml of normal saline in the treatment group which was used for irrigation during surgery; control eyes were irrigated with normal saline. The incidence of the OCR, rate of postoperative nausea/vomiting (PONV), total intravenous (IV) analgesic dose, duration of surgery, and period of hospitalization were compared between the study groups. Results: Thirty eyes of 30 patients including 22 (73.3%) male and 8 (26.7%) subjects with mean age of 49.4΁16.3 years were operated. OCR and PONV occurred less frequently, and total intravenous analgesic dose was significantly lower in the lidocaine group (P < 0.05 for all comparisons). However, no significant difference was noted between the study groups in terms of duration of surgery and period of hospitalization. Conclusion: Adjunctive local application of lidocaine during SB under GA for RRD decreases the rate of OCR and PONV, reduces the intravenous analgesic dose, but does not affect the duration of surgery or hospitalization