Efficient Rewirings for Enhancing Synchronizability of Dynamical Networks

In this paper, we present an algorithm for optimizing synchronizability of complex dynamical networks. Based on some network properties, rewirings, i.e. eliminating an edge and creating a new edge elsewhere, are performed iteratively avoiding always self-loops and multiple edges between the same nodes. We show that the method is able to enhance the synchronizability of networks of any size and topological properties in a small number of steps that scales with the network size.Although we take the eigenratio of the Laplacian as the target function for optimization, we will show that it is also possible to choose other appropriate target functions exhibiting almost the same performance. The optimized networks are Ramanujan graphs, and thus, this rewiring algorithm could be used to produce Ramanujan graphs of any size and average degree

An inquiry into non-survey techniques for updating input-output coefficients: Comparative experiments with data from the Soviet Union

The study begins with explanation of I-O tables, intertemporal stability of its coefficients, and logic of updating techniques. Following a literature review, nine non-survey updating methods are selected and utilized to update the actual 1966 table of the Soviet Union to the target year of 1972. Next, the data and simulation procedure are specified and justified. The concept of matrix comparison along with methods to accomplish this task are discussed. Then, the resultant updated matrices are compared with the actual data, via employment of 25 criterions. Accordingly, RAS and Friedlander procedures are ranked as top performers. The results, while reasonable in holistic sense, are not impressive partitively. Exogenous estimation of a subset of coefficients is considered next. Several possibilities for selective targeting are investigated, and three such criterions, namely key, most important, and largest coefficients are adopted. These criterions, then are used to modify RAS, Friedlander, and NAIVE methods via incorporation of exogenous data. An additional approach, Residual Minimum method, is also employed. Thus, ten modified estimates are obtained and compared with the actual table. The outcome indicates substantial improvements in the RAS and Friedlander updates, particularly when exogenously estimated subset consists of the largest, or the most important coefficients. NAIVE method displays reasonable improvement. Inclusion of prior information, however, in some instances leads to deterioration of individual estimates for the remaining coefficients. Finally, sectoral aggregation and its effects on the performances of updating methods are addressed. Aggregated estimates at three levels of sectoral details, i.e., 36, 16, and 6 sectors, are obtained and comparisons are performed. The results indicate that, generally the performances of the updating methods, as well as the intertemporal stability of coefficients, are direct functions of the level of sectoral detail. No change in ranking occurs due to aggregation, Conclusions of this research may be used for selection of updating methods, as well as in construction phase of tables, to identify and focus on the most influential coefficients. Throughout, a rather detailed presentation of methods and statistical tools are offered. All experiments are conducted for both direct and inverse matrices. NAIVE, (constant coefficient), is added for comparative purposes

Activities of Medical Educational Development Center from the Views of the Faculty Members of Kerman Medical Sciences University

Background: The necessity of improving academic and higher education quality, particularly in Medical Sciences Universities and increasing the efficiency of Health care and Remedy programs are obvious. Medical Educational Development Centers try to achieve their goals in the areas of curriculum planning, teacher training, continuing education, evaluation and research in education. Objective: The aim of this study was to investigate the views of the faculty members of Kerman Medical Sciences University about the activities of Medical Educational development center. Methods: This cross-sectional study carried out in 2003. The sample consisted of the faculty members of Kerman Medical Sciences University (N=307) of which about half (n=145) were selected by simple random sampling. Data were gathered through a researcher – made questionnaire that rated by experts for validity and computed internal consistency reliability with cronbach’ alpha coefficient of (r=0.79). Results: According to the results, the most accepted activities of the center were “Designing and carrying out clinical skills educational programs for medical students” (96.6%), “active participation in the revision of medical educational programs” (93.1%), “cooperation with educational departments in designing lesson plans based on new materials and resources” and “Holding educational workshops for the familiarization of the faculty members with new medical softwares and their applications” (each 92.4%). While the least accepted activities were providing “facility for lectures”, “access to resources, gathering and symposiums on medical education” and “taking advantage of the experienced instructors in designing programs for the center” (each 61.4%), “participation in the evaluation of research projects and dissertations” and “helping the medical society to have a better understanding of the changing medical needs of the community” (each 67%). In whole by obtaining 78.7% of the total score, the faculty members showed a relatively positive view towards current activities of the center. From all subjects, 87.5% showed tendency for participating in the activities of the center. Conclusion: The positive view of the faculty members towards current activities of the center is a turning point in further expansion of the center and establishing the same units in all colleges to improve medical education goals

A study of pain and anxiety/ depression severity on patients with nonspecific chronic low back pain

Background and aims: Patients with low back pain like other chronic diseases, may experience psychological symptoms in addition to physical symptoms which leads to the exacerbation of the condition of these patients and reduce their quality of life. Due to lack of clinical studies in this field, this study was conducted to investigate the relationship between pain and severity of depression and anxiety in patients with nonspecific chronic low back pain. Methods: This analytic- descriptive study was performed on 250 patients with nonspecific low back pain referring to the orthopedic clinic in Shahrekord selected by convenience sampling. Demographic questionnaire, visual analogue scale of pain, Beck Depression Inventory and Beck Anxiety Inventory were used to collect the patient’s information, pain severity, anxiety and depression. Stata software 14 was used for data analysis. Results: Mean ± SD of pain in women was 4.6±1.21 and higher than in men (4.1±1.25). Pain severity showed a significant difference between the groups of patients with different levels of anxiety and depression (P<0.01). There was a significant difference among non-smokers for pain rate between the groups, according to the levels of depression (P<0.05). Conclusion: Patients with nonspecific chronic low back pain experience higher level of pain with increasing severity of depression and anxiety. It is necessary in treatment of patients with nonspecific low back pain to pay attention to their psychological dimensions in addition to treating physical problems to reduce pain, and take action to relieve for the modulation of anxiety, depression and quality of life in these patients

Chaotic biogeography algorithm for size and shape optimization of truss structures with frequency constraints

Size and shape optimization of truss structures with natural frequency constraints is inherently nonlinear dynamic optimization problem with  several local optima. Therefore theoptimization method should be sagacious enough to avoid being trapped in local optima and in this way to reduce premature convergence. To address this problem, we develop a Chaotic Biogeography-Based Optimization (CBBO) algorithm which combines the chaos theory and the biogeography-based optimization (BBO) to achieve an ecient optimization method. In this method, new chaotic migration and mutation operators are proposed to enhance the exploration ability of BBO. The performance of the method is demonstrated through five benchmark design examples with size and shape variables associated by multiply frequency constraints. The results show the eciency and robustness of proposed method and in most cases, CBBO finds a relatively lighter structural weight than those previously reported results in the literature

Evaluation of E-cadherin (CDH1) gene polymorphism related to gastric cancer in Kurdish population

Abstract: Helicobacter pylori (H.pylori) infection induces inflammation in gastric mucosa that may progress to gastric cancer that causes of much mortality. This cancer is a multistage process involved changes in environmental, genetic and epigenetic factors. Polymorphism in promoter of CDH1 gene is associated with reduced E-cadherin protein expression. Gastric cancer is associated with multiple changes nucleotides in CDH1 gene. Aimed: We were evaluating -160 (C>A) CDH1 gene polymorphism associations with gastric cancer in Kurdish population. Methods: A total of 306 biopsies taken from corpus of 144 gastric cancer patients and 162 nonulcer dyspepsia patients were classified as H.pylori-infected and H.pylori-uninfected. All diagnoses confirmed pathologically and molecularly. Polymorphism in -160(C>A) CDH1 was evaluated by PCR-RFLP. Results: Polymorphism of -160 (C>A) CDH1 in H.pylori-uninfected and H.pylori-infected groups were not associated with gastric cancer (p > 0.05). Also there was not relationship between -160(C>A) CDH1 genotypes and H.pylori infection susceptibility (p > 0.05). We found significant relationship between CC genotype and survival time among gastric cancer patients (p = 0.01). Conclusion: -160(C>A) CDH1 polymorphism may regardless of presence or absence of H.pylori, don’t influences gastric cancer sensibility in Kurdish population. In other hand CC genotype, as a good trait, increases period of life for Kurdish cancer patients