Actinomycosis may be presented in unusual organs: A report of two cases

Actinomycosis is a chronic granulomatous suppurative disease characterized by direct extension to the contagious tissue with the formation of multiple drainage sinus tracts through which tiny colonies of organisms called sulfur granules are discharged. Here, we report 2 cases of actinomycosis from Iran. One of them had actinomycosis on the hand and the other on the foot. Samples of tissue biopsy showed sulfur granules associated with colonies of actinomyces, thus confirming the diagnosis in both cases. The response to curettage and penicillin therapy was satisfactory in our patients. The chronic and indolent course of actinomycosis resembles tuberculosis, fungal infection and malignancy. So, increasing awareness among the clinicians and clinical microbiologists will help in the early diagnosis of the disease and in the initiation of early and proper treatment

Transparency effect in the emergence of monopolies in social networks

Power law degree distribution was shown in many complex networks. However, in most real systems, deviation from power-law behavior is observed in social and economical networks and emergence of giant hubs is obvious in real network structures far from the tail of power law. We propose a model based on the information transparency (transparency means how much the information is obvious to others). This model can explain power structure in societies with non-transparency in information delivery. The emergence of ultra powerful nodes is explained as a direct result of censorship. Based on these assumptions, we define four distinct transparency regions: perfect non-transparent, low transparent, perfect transparent and exaggerated regions. We observe the emergence of some ultra powerful (very high degree) nodes in low transparent networks, in accordance with the economical and social systems. We show that the low transparent networks are more vulnerable to attacks and the controllability of low transparent networks is harder than the others. Also, the ultra powerful nodes in the low transparent networks have a smaller mean length and higher clustering coefficients than the other regions.Comment: 14 Pages, 3 figure

Test-bed development & measurement plan for evaluating transmit diversity in DVB networks

This paper presents a test-bed development and measurement plan for evaluating transmit diversity in the DVB network. Transmit diversity reduces the complexity and improves the power consumption of the personal receiving devices by improving the transmission of signals in NLOS cluttered environments. Also, it is more practical than receive diversity due to the difficulty of locating two receive antennas far enough apart in a small mobile device. Test service scenarios were developed to illustrate the benefits of such technologies so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems. The laboratory tests were designed to validate the theoretical measurements from the theoretical analysis and these results will be verified by a field measurement campaign in short and long time spans

Gendered science questioning: To boys or not to boys, that is the question

Science teachers are continually under scrutiny as researchers explore how they attempt to enable their students to ‘do science’ both in school and in preparation for ‘becoming scientists’. Questions have been raised, for instance, about the tendency of boys to dominate in science lessons by gaining more of teacher attention compared with girls during dialogic interactions. Drawing on notions of gendered learning within the context of science teacher questioning, this research examines whether there is a tendency for teachers to address questions during classroom dialogue to boys over girls in secondary science classrooms. Data were collected in 211 science classes in London, UK. Pre-service science teachers mapped whom teachers asked questions to during randomly selected lessons, and reflected on their strategies and intentions. In addition, a teacher-researcher carried out teacher and student surveys and an in-depth student focus group interview in their school, in which 14-15 year old students are taught science in both mixed- and single-gendered settings, to examine any perceptions of gendered learning. Early evidence shows there may be a gender bias towards teachers asking boys questions more frequently, sometimes as part of behaviour management agendas rather than as direct scaffolding for learning ideas. Teacher perceptions of boys responding more readily to competitive learning were refuted by girls in our sample. Students did not perceive gendered grouping as aiding their learning or their enjoyment of it. This study has implications for teacher training, and teachers’ preconceptions of how girls and boys may respond to different learning approaches in the science classroom

Measurements, processing functions and laboratory test-bed experiments for evaluating diversity in broadcast network

This paper presents a test-bed development and measurement plan for evaluating transmit diversity and on-channel repeaters in the Digital Video Broadcasting Network. Transmit diversity reduces the complexity and improves the power consumption of the personal receiving devices by enhancing the transmission of signals in NLOS cluttered environments. It is more practical than receive diversity due to the difficulty of locating two receive antennas far enough apart in a small mobile device. The on-channel repeater is to extend the coverage of the DVB-T/H network in areas where services are inaccessible by receiving the DVB-T/H signals off air, amplifying and then retransmitting it on the same frequency as received. Test service scenarios were developed to illustrate the benefits of such technologies so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems.The work presented in this paper was supported by the European Commission IST project PLUTO

Laboratory measurement campaign of DVB-T signal with transmit delay diversity

The requirements for future DVB-T/H networks demand that broadcasters design and deploy networks that provide ubiquitous reception in challenging indoors and other obstructed situations. It is essential that such networks are designed cost-effectively and with minimized environmental impact. The EC funded project PLUTO has since its start in 2006 explored the use of diversity to improve coverage in these difficult situations. The purpose of this paper is to investigate the performance of Transmit Delay Diversity (DD) with two antennas to improve the reception of DVB-T/H systems operating in different realistic propagation conditions through a series of tests using a SPIRENT SR5500 dual channel emulator. The relationship between correlation coefficient between channels, receiver velocity and diversity gain is nvestigated. It is shown that transmit delay diversity significantly improves the quality of reception particularly in simulated fast fading mobile broadcasting applications. This paper documents research conducted by Brunel University and Broadreach Systems

Field trials and test results of portable DVB-T systems with transmit delay diversity

This paper describes work carried out by Brunel University and Broadreach Systems (UK) to quantify the advantages that can be achieved if Transmit Diversity is applied to systems employing the DVB standard. The techniques investigated can be applied to standard receiver equipment without modification. An extensive and carefully planned field trial was performed during the winter of 2007/2008 in Uxbridge (UK) to validate predictions from theoretical modeling and laboratory simulations. The transmissions were performed in the 730 MHz frequency band with a DVB-T transmitter and a mean power of 18.4dBW. Transmit delay diversity has been observed to deliver significant reception improvement in automotive and indoor- non line of sight situations

Time-Varying Lyapunov Control Laws with Enhanced Estimation of Distribution Algorithm for Low-Thrust Trajectory Design

Enhancements in evolutionary optimization techniques are rapidly growing in many aspects of engineering, specifically in astrodynamics and space trajectory optimization and design. In this chapter, the problem of optimal design of space trajectories is tackled via an enhanced optimization algorithm within the framework of Estimation of Distribution Algorithms (EDAs), incorporated with Lyapunov and Q-law feedback control methods. First, both a simple Lyapunov function and a Q-law are formulated in Classical Orbital Elements (COEs) to provide a closed-loop low-thrust trajectory profile. The weighting coefficients of these controllers are approximated with various degrees of Hermite interpolation splines. Following this model, the unknown time series of weighting coefficients are converted to unknown interpolation points. Considering the interpolation points as the decision variables, a black-box optimization problem is formed with transfer time and fuel mass as the objective functions. An enhanced EDA is proposed and utilized to find the optimal variation of weighting coefficients for minimum-time and minimum-fuel transfer trajectories. The proposed approach is applied in some trajectory optimization problems of Earth-orbiting satellites. Results show the efficiency and the effectiveness of the proposed approach in finding optimal transfer trajectories. A comparison between the Q-law and simple Lyapunov controller is done to show the potential of the potential of the EEDA in enabling the simple Lyapunov controller to recover the finer nuances explicitly given within the analytical expressions in the Q-law

Social network analysis of Iranian researchers on medical parasitology: A 41 year co-authorship survey

Background: The aim of this study was to survey the Iranian Parasitology researchers� performance, and analyse and visualize the scientific outputs of their co-authorship network. Methods: This study was conducted using scientometric method and social network analysis (SNA). The data extracted from the Web of Science (WoS) databases in July 10th 2014. Totally, 1048documents of all types in research area of Parasitology during 1972-2013 by Iranian researches retrieved. The coauthorship map was drawn utilizing NETDRAW, Coauthor.exe, and UCINET softwares and was analysed based on SNA measures. Results: The researchers� co-authorship network consisted of 78 authors and its density degree is 0.57. �Mohebali� ranked top in all of centrality measures.The most of the publications were related to 2012, �Mohebali� with about 9 of all documents was the Iranian most prolific author in Parasitology field. The Iranian researches have published mostly (266 documents) in �Iranian Journal of Parasitology�, and the most of the documents belong to �Tropical Medicine� subject field. The most of Iranian researchers� scientific cooperation was performed with England and United States. Conclusion: Bringing forth density degree (is 0.57) showed that this network has an almost medium density. Indeed, the authors have had relations in moderate level with each other in the network. The findings of this study can be identified aspects of scientific collaboration, and help policy makers of Parasitology field research. © 2016, Tehran University of Medical Sciences (TUMS). All rights reserved