A Unified Scheme for Modular Invariant Partition Functions of WZW Models

We introuduce a unified method which can be applied to any WZW model at arbitrary level to search systematically for modular invariant physical partition functions. Our method is based essentially on modding out a known theory on group manifold $G$ by a discrete group $\Gamma$. We apply our method to $\widehat {su(n)}$ with $n=2,3,4,5,6$, and to $\widehat {g_2}$ models, and obtain all the known partition functions and some new ones, and give explicit expressions for all of them.Comment: 30 page ,SUTDP/11/93/72 Department of Physics, Sharif University of Technolog

A Triangular Deformation of the two Dimensional Poincare Algebra

Contracting the $h$-deformation of \SL(2,\Real), we construct a new deformation of two dimensional Poincar\'e algebra, the algebra of functions on its group and its differential structure. It is also shown that the Hopf algebra is triangular, and its universal R matrix is also constructed explicitly. Then, we find a deformation map for the universal enveloping algebra, and at the end, give the deformed mass shells and Lorentz transformation.Comment: 11 pages, LaTeX, Two figures upon reques

A New Protocol for Cooperative Spectrum Sharing in Mobile Cognitive Radio Networks

To optimize the usage of limited spectrum resources, cognitive radio (CR) can be used as a viable solution. The main contribution of this article is to propose a new protocol to increase throughput of mobile cooperative CR networks (CRNs). The key challenge in a CRN is how the nodes cooperate to access the channel in order to maximize the CRN's throughput. To minimize unnecessary blocking of CR transmission, we propose a so-called new frequency-range MAC protocol (NFRMAC). The proposed method is in fact a novel channel assignment mechanism that exploits the dependence between signal's attenuation model, signal's frequency, communication range, and interference level. Compared .to the conventional methods, the proposed algorithm considers a more realistic model for the mobility pattern of CR nodes and also adaptively selects the maximal transmission range of each node over which reliable transmission is possible. Simulation results indicate that using NFRMAC leads to an increase of the total CRN's throughput by 6% and reduces the blocking rate by 10% compared to those of conventional methods

Mothers’ experience of having children with diabetes

Abstract Background: Diabetes is a major health problem, which has a wide prevalence in the world. There is no sign of its stopping, but it is increasing. Diabetes in children is three to four times more common than other childhood diseases. Diagnosis of diabetes for children causes emotional responses in parents and family members. Interventions for children with diabetes involve the family, child, and professionals including physicians, nurses, and nutritionist. Self-care is difficult without direct parents’ participation. According to studies, burden of diabetes for mothers is more than for fathers. This study aimed to explore mothers’ experience of children with diabetes. Materials and Methods: This is a qualitative content analysis. Study population was recruited through purposeful sampling. Eleven mothers who have a child with diabetes and referring to the “Glands and Metabolism Research Center” and “Al-Zahra Hospital” were selected. Participants were aged 28 to 42 years. Data gathering was done through deep interviews with participants in 2007 that was tape-recorded. Mean average of interviews was 45 minutes. Data analysis was done using conventional qualitative content analysis. Results: Participants’ experience was classified in the two main concepts including reaction at the time of diagnosis and disease consequences for mothers. Conclusion: Mothers of children with diabetes expressed some reactions at the time of diagnosis, which was mainly due to lack of information, and lack of attention to their needs at the time of diagnosis, especially it was due to the sudden diagnosis and lack of enough opportunities for mothers to accept the disease. The disease causes some consequences for mothers that affect their lives. Therefore, it is necessary to consider the needs of families of children with diabetes and to provide support and sufficient information about their child’s illness for them

Stakeholders' perspective on health equity and its indicators in Iran: A qualitative study

Background: To reduce the health inequity, it is necessary to measure and monitor these inequalities. In this regard, in Iran a plan was developed and accordingly 52 indicators to measure equity in health were developed and announced by the Ministry of Health in collaboration with other sectors. This study aims to obtain a deeper understanding of the development of health equity indicators and identify their implementation challenges and proposed solutions from the perspective of policy makers and executives responsible for the indicators development and implementation. Methods: In this qualitative study, data were gathered using semi-structured interviews with 15 Stakeholders involved in the development and implementation of these health equity indicators (at national and provincial levels), and the review and analysis of relevant documents including meeting minutes, working plans and working progress reports. Data were analyzed using a framework analysis approach. Results: Four main themes were identified, including the concept of equity in health and its importance, the use of health equity indicators and process of indicators development, challenges of development and implementation of the indicators and laying the groundwork for the establishment of indicators. The findings showed that policy makers' viewpoint on concepts and indicators is different from those of executives and their perceptions have little in common. The establishment of indicators requires accurate stakeholders' understanding and accurate insight into the issue of equity in health, political will, financing, training and empowerment of organization's employees, legal requirements, and finally a clear action plan. Conclusion: The development of the indicators requires a shared understanding among policy makers and executives. As the attention has been focused recently on the issue, in addition to knowledge improvement, proper solutions with an intersect oral collaboration approach in order to tackle challenges should be considered

Beating ratio 0.5 for weighted oblivious matching problems

ESA 2016 is organized in collaboration with the European Association for Theoretical Computer Science (EATCS) and is a part of ALGO 2016We prove the first non-trivial performance ratios strictly above 0.5 for weighted versions of the oblivious matching problem. Even for the unweighted version, since Aronson, Dyer, Frieze, and Suen first proved a non-trivial ratio above 0.5 in the mid-1990s, during the next twenty years several attempts have been made to improve this ratio, until Chan, Chen, Wu and Zhao successfully achieved a significant ratio of 0.523 very recently (SODA 2014). To the best of our knowledge, our work is the first in the literature that considers the node-weighted and edge-weighted versions of the problem in arbitrary graphs (as opposed to bipartite graphs). (1) For arbitrary node weights, we prove that a weighted version of the Ranking algorithm has ratio strictly above 0.5. We have discovered a new structural property of the ranking algorithm: if a node has two unmatched neighbors at the end of algorithm, then it will still be matched even when its rank is demoted to the bottom. This property allows us to form LP constraints for both the node-weighted and the unweighted oblivious matching problems. As a result, we prove that the ratio for the node-weighted case is at least 0.501512. Interestingly via the structural property, we can also improve slightly the ratio for the unweighted case to 0.526823 (from the previous best 0.523166 in SODA 2014). (2) For a bounded number of distinct edge weights, we show that ratio strictly above 0.5 can be achieved by partitioning edges carefully according to the weights, and running the (unweighted) Ranking algorithm on each part. Our analysis is based on a new primal-dual framework known as matching coverage, in which dual feasibility is bypassed. Instead, only dual constraints corresponding to edges in an optimal matching are satisfied. Using this framework we also design and analyze an algorithm for the edge-weighted online bipartite matching problem with free disposal. We prove that for the case of bounded online degrees, the ratio is strictly above 0.5.published_or_final_versio

Antidepressant-like Effect of Extracts From Urtica Dioica in Mice Model of Depression

Urtica dioica (Stinging nettle) leaves have been used as a traditional medicine to treatrheumatoid arthritis, to alleviate rheumatic pain benign prostatic hyperplasia (BPH), diuretic and prevention of kidney stones by local people in Middle East region especially in Iran, Turkey and East Europe. Hence, this investigation evaluates the antidepressant effect of selected crude extracts in the forced swimming test (FST) and tail suspension test (TST), two models predictive of antidepressant activity. The acute treatment of mice with extracts by intra-peritoneal (i.p.) route significantly reduced the immobility time in the FST (50 and 100 mg/kg) and TST (50 and 100 mg/kg), as compared to positive controls (haloperidol and fluoxetine) at 1 and 10 mg/kg, respectively. On the third day of experiment, a significant decrease of mobility was observed for chloroform extract (CE I) and butanol extract (BE II) compared to first day. CE I and BE II led to reduction of immobility time, as the selected extracts with two doses administered were different compared to the control, in the FST method by 65.37% and53.92% for 100 mg/kg, respectively. However, CE I showed the best result compared to our positive controls. Similar results of increased antidepressant effect, that was, of immobility time depending on the concentration administered, were obtained with the TST method. Also our data showed that there was no significant differences between doses (50 and 100 mg/kg). The results suggested that the antidepressant action of the butanol extract and of U. dioica its fraction (BE II2) was mediated by an interaction with 5-hydroxytrptamine (5-HT). U. dioica showed a potential source for the isolation of important natural products with antidepressant-like properties. However, further studies are still require

Coined quantum walks on percolation graphs

Quantum walks, both discrete (coined) and continuous time, form the basis of several quantum algorithms and have been used to model processes such as transport in spin chains and quantum chemistry. The enhanced spreading and mixing properties of quantum walks compared with their classical counterparts have been well-studied on regular structures and also shown to be sensitive to defects and imperfections in the lattice. As a simple example of a disordered system, we consider percolation lattices, in which edges or sites are randomly missing, interrupting the progress of the quantum walk. We use numerical simulation to study the properties of coined quantum walks on these percolation lattices in one and two dimensions. In one dimension (the line) we introduce a simple notion of quantum tunneling and determine how this affects the properties of the quantum walk as it spreads. On two-dimensional percolation lattices, we show how the spreading rate varies from linear in the number of steps down to zero, as the percolation probability decreases to the critical point. This provides an example of fractional scaling in quantum walk dynamics.Comment: 25 pages, 14 figures; v2 expanded and improved presentation after referee comments, added extra figur