A Deterministic Polynomial--Time Algorithm for Constructing a Multicast Coding Scheme for Linear Deterministic Relay Networks

We propose a new way to construct a multicast coding scheme for linear deterministic relay networks. Our construction can be regarded as a generalization of the well-known multicast network coding scheme of Jaggi et al. to linear deterministic relay networks and is based on the notion of flow for a unicast session that was introduced by the authors in earlier work. We present randomized and deterministic polynomial--time versions of our algorithm and show that for a network with $g$ destinations, our deterministic algorithm can achieve the capacity in $\left\lceil \log(g+1)\right\rceil$ uses of the network.Comment: 12 pages, 2 figures, submitted to CISS 201

Clinical microbiology study of diabetic foot ulcer in Iran; pathogens and antibacterial susceptibility

The aim of this study was to investigate microbial pathogens and their antibiotic susceptibility profile in infected diabetic foot ulcers in Iranian patients. This was a one-year cross sectional study on diabetic patients with infected diabetic foot ulcer at Shariati Teaching Hospital, Tehran, Iran. Grade of ulcer was determined by Wagner's criteria. Specimens were obtained from the base of ulcer, deep part of the wound or aspiration and were tested with gram staining and antibacterial susceptibility was determined with both disk diffusion and E-Test methods. Total of 546 pathogens were isolated from 165 ulcers of 149 patients. Gram positive aerobes including Enterococcal species and methicillin resistant Staphylococcus aureus (S. aureus) (21.4 and 19.4%, respectively) were identified as the most common pathogens followed by Gram negative isolates including Escherichia coli and Pseudomonas-aeruginosa (12.6 and 5.4%, respectively). The majority of wounds were classified as Wagner grades 2 and 3 (15.7 and 75.7%). Appropriate empiric treatment to cover both these Gram positive and Gram negative pathogens is crucially important

A New Amplification Regime for Traveling Wave Tubes with Third Order Modal Degeneracy

Engineering of the eigenmode dispersion of slow-wave structures (SWSs) to achieve desired modal characteristics, is an effective approach to enhance the performance of high power traveling wave tube (TWT) amplifiers or oscillators. We investigate here for the first time a new synchronization regime in TWTs based on SWSs operating near a third order degeneracy condition in their dispersion. This special three-eigenmode synchronization is associated with a stationary inflection point (SIP) that is manifested by the coalescence of three Floquet-Bloch eigenmodes in the SWS. We demonstrate the special features of "cold" (without electron beam) periodic SWSs with SIP modeled as coupled transmission lines (CTLs) and investigate resonances of SWSs of finite length. We also show that by tuning parameters of a periodic SWS one can achieve an SIP with nearly ideal flat dispersion relationship with zero group velocity or a slightly slanted one with a very small (positive or negative) group velocity leading to different operating schemes. When the SIP structure is synchronized with the electron beam potential benefits for amplification include (i) gain enhancement, (ii) gain-bandwidth product improvement, and (iii) higher power efficiency, when compared to conventional Pierce-like TWTs. The proposed theory paves the way for a new approach for potential improvements in gain, power efficiency and gain-bandwidth product in high power microwave amplifiers.Comment: 15 pages, 11 figure

Size-dependent bond dissociation enthalpies in single-walled carbon nanotubes

We report the bond dissociation enthalpy (BDE) and the local electronic properties of Single-Walled Carbon Nanotubes (SWCNT) using density functional theory. Our analysis shows that there is a strong size-dependence of the BDE of these SWCNTs, which is inversely proportional to the radius-squared (1/r2) and the length (1/l) of SWCNT. We derive quantitative relationships from which the BDE can be calculated as a function of size and radius of the SWCNT. We find that the BDE of SWCNT outside the size-dependent region is about 480 kJ mol−1, which can be used for thermochemical calculations

Evaluating outcome of distal tibia and fibula fractures treated with intra medullary nailing

Choice of best treatment in tibiofibular fractures should be based on many affecting factors such as age, wound contamination's, presence of associated conditions and availability of stabilization devices. This study is aimed to evaluating outcome of distal tibia and fibula fractures treated with intra medullary nailing in Firoozgar hospital during 2012-2014. In this cross- sectional study which was conducted in Firoozgar hospital in 2012-2014, 40 patients with distal tibiofibular fractures who was candidate for IM nailing were evaluated. Operation was done by intramedullary nailing method. Patients were followed up at 2 weeks, 1, 3, 6 and 12 month after surgery. Radiographic evaluation of union in tibia with anteroposterior and lateral view, as well as complications was assessed in each visit. Data were enterd to SPSS and were analyzed. Fifty patients with mean age of 34.67 (SD= 12.98) years (46 (92) male and 4 (8) female) were evaluated. Four (10) patients remained non- union from whom 3 (7.5) underwent ORIF treatment. Mean time of complete union achievement was 6.34 (SD= 3.54) months. Fourteen malunion were seen in this study that 1 (7.14) was varus (7°) and 13 (92.85) were valgus. No cases of deep infection, nerve injury or compartment syndrome were seen. We conclude that reamed, locked IM. nailing is a good method for achieving union in distal tibial fractures. High rate of union, low complication and deformity correction was seen with this method. © 2016, Oriental Scientific Publishing Company. All rights reserved

Data Analysis of a National Health and Nutrition Examination Survey (NHANES) to identify the relationship between obesity and cancer

Introduction: Obesity and cancer independently are two important causes of death in the USA. A growing number of studies shows that these two chronic illnesses are related. Objective: To examine the relationship of cancer and obesity using BMI and Waist Circumference (WC) as indicators using the National Health and Nutrition Examination Survey (NHANES) dataset. Method: NHANES (2013-2014) dataset was used to obtain information on BMI, Waist Circumference (WC), and cancer (presence or absence) among the participants. The prevalence of obesity and cancer was tested with Pearson λ^2 test and the relationship of these two with education (5 levels) was examined using logistic regression. The effect of confounding variables (gender and race) was also tested. Results: The participants who had been diagnosed with cancer were 9.5% of the total participants (11483). More than half of the participants (55%) had taken some college courses or graduated from college. The prevalence of cancer was higher (7.8% more) in females than males. The association of cancer with both BMI and Waist Circumference was significant but weak (p\u3c0.05). The effects of age and gender were significant. By adjusting the model with race and gender R2 increased to 10.3 and all variables were significant in the model ( λ^2(11) =490.931, p\u3c0.001). Conclusion: Attention to proper diet and following the recommended guidelines could help individuals to somehow prevent obesity and/or cancer, which eventually would increase the quality of public health