Seed selection for information cascade in multilayer networks

Information spreading is an interesting field in the domain of online social media. In this work, we are investigating how well different seed selection strategies affect the spreading processes simulated using independent cascade model on eighteen multilayer social networks. Fifteen networks are built based on the user interaction data extracted from Facebook public pages and tree of them are multilayer networks downloaded from public repository (two of them being Twitter networks). The results indicate that various state of the art seed selection strategies for single-layer networks like K-Shell or VoteRank do not perform so well on multilayer networks and are outperformed by Degree Centrality

Rate-dependent and antiarrhythmic reentrant tachycardia (AVNRT) effects of simvastatin in isolated rabbit atrioventricular nodal model

Background and purpose: Several previous studies have shown the direct and indirect effects of statins on supraventricular and ventricular arrhythmia. The purpose of the present study is to determine (1) whether Simvastatin modifies the rate-dependent properties of the AV node, (2) to what extent such changes are related to effect of Simvastatin on the basic properties of AV nodal conduction and refractoriness. Materials and methods: AV nodal refractoriness (AVERP & AVFRP) and rate dependency protocols Fatigue and Facilitation were used to assesse the electrophysiological properties of AV node. We used an isolated perfussed rabbit with AV nodal preparation in one group (N=8). The stimulation protocols were carried out during control phase and in the presence of various concentrations of Simvastatin (0.5 , 0.8 , 1, 3 ,10 μm). Results: Simvastatin in concentration-dependent manner successfully prolonged effective and functional nodal refractory period (AVERP & AVFRP). Also an increase in Wenckebach cycle length was observed. Simvastatin in high concentration (3,10 μm) increases the arrhythmia threshold. Various concentrations of simvastatin increased fatigue, but it reached to significant level only at 30 μM. Conclusion: Simvastatin has potential anti-AVNRT effects by elevating arrhythmia threshold and prolongation of nodal refractoriness

Peach witches’-broom, an emerging disease associated with ‘Candidatus Phytoplasma phoenicium’ and ‘Candidatus Phytoplasma aurantifolia’ in Iran

During field surveys carried out from 2013 to 2017 in the eight main peach producing provinces of Iran, symptoms of a phytoplasma-like peach witches'-broom disease (PWIB), inducing severe yellowing, little leaf, internode shortening, crown and stem witches\u2019-broom, decline, and death, were observed. The aim of this work was to identify and characterize the agent(s) associated with PWIB by biological assays and molecular analyses. PWIB agents were successfully transmitted under controlled conditions from scions of in field-affected peach trees, exhibiting severe or mild symptoms, to peach and bitter almond seedlings inducing phytoplasma-like symptoms. A 16S rDNA fragment of 1250 bp was amplified by nested-PCR from all PWIB-affected trees and grafted seedlings. Nucleotide sequence identity, presence of species-specific signature sequences, in silico RFLP, single nucleotide polymorphisms, and phylogenetic analyses of 16S rDNA allowed the assignation of the phytoplasma strains identified in seven Iranian provinces in peach trees with severe PWIB symptoms to four SNP genetic lineages of \u2018Ca. P. phoenicium\u2019 (subgroup 16SrIX-B and its variant). PWIB phytoplasma strains identified in Abarkooh (Yazd province) in peach trees with mild symptoms were attributed to the species \u2018Ca. P. aurantifolia\u2019 (subgroup 16SrII-C). This report of a wide spread of \u2018Ca. P. phoenicium\u2019 in association with PWIB in Iran supported its capability of adaptation to a broad range of fruit tree species, such as peach, nectarine, and apricot. As \u2018Ca. P. phoenicium\u2019 and \u2018Ca. P. aurantifolia\u2019 are the etiological agents of other important plant diseases in Iran and neighbouring countries, further investigations are needed to determine the role played by peach in their epidemiological pathways

A Pareto Front Approach to Bi-objective of Distillation Column Operation Using Genetic Algorithm

In this paper, an exergy analysis approach is proposed for optimal design of distillation column by using Genetic algorithm. First, the simulation of a distillation column is performed by using the shortcut results and irreversibility in each tray is obtained. The area beneath the exergy loss profile is used as Irreversibility Index for exergy criteria. Then, two targets optimization algorithm (SA, Simulated Annealing) is used to maximize recovery and minimize irreversibility index in a column by six different variables (Feed Condition, Reflux Rate, Number of theoretical stage, Feed Trays (Feed Splitting, three variables)). SA uses one objective function for the purpose or alters two targets optimization to one target optimization. Then, GA optimization algorithm is used for two targets optimization except Pareto set which is used instead of objective function; finally, the results are compared with SA results. Then, one pump-around is considered to obtain better results (OPT2). Irreversibility index criterion is compared with exergetic efficiency, constant and variable feed composition splitters are considered.Key words: Exergy analysis; Irreversibility index; Genetic algorithm; Process optimization; Distillation colum

Age-dependent dynamic electrophysiological field potential behavior of atrioventricular node during experimental AF in rabbit

Introduction: Electrophysiological studies have demonstrated a relationship between aging and atrioventricular (AV) nodal conduction and refractoriness. The aim of the present study was to determine the effects of nodal aging on dynamic AV nodal field potential recording during atrial fibrillation (AF) in rabbit. Methods: Two groups of male New Zealand rabbits (neonatal 2-week-olds and adult 12-week-olds, n=14 each group) were used in this study. Field potential recordings were executed by silver electrodes with a diameter of 100 μM. Pre-defined stimulation protocols of AF, zone of concealment (ZOC) and concealed conduction for determination of the electrophysiological properties of the AV-node were separately applied in each group. Results: Results of the study showed that mean ventricular rate (HH) during atrial fibrillation was smaller in the neonatal compared to the adult group (229.1 ± 8.3 versus 198.6 ± 13.1 msec, respectively). Also ventricular distribution conduction pattern showed two peaks in the adult and one peak in the neonatal group. Analyzing the zone of concealment in different rates and after concealed beat indicated that the zone of concealment in neonates were significantly smaller compared with adult rabbits and increasing zone of concealment, which is accompanied with increasing ventricular rate is abrogated in the neonatal group (5 ± 3.3, 12.2 ± 6.3 msec). Conclusion: The results of this study showed that the electrophysiological protective dynamic behavior of the AV node during atrial fibrillation is smaller in neonates compared to adults. Narrower zone of concealment, abrogation rate dependent trend of the zone of concealment and shorter nodal refractoriness can account for the specific nodal electrophysiological properties of neonatal rabbits

Formation of Nanostructured Al-Mg-Si Alloys and Evaluation Its Properties

In this study, nanostructured Al-Mg-Si (Al6061) alloy was prepared from elemental powders by mechanical alloying and heat treatment. 98.4% aluminum, 1% magnesium, 0.6% silicon powders were mixed and mechanically alloyed under argon atmosphere. The rotation speed of 500rpm and ball to powder ratio of 10:1 was employed. The mechanical alloyed powder was isothermally heat treated at 400 degrees Celsius for 2 h under argon atmosphere. The results showed that after 10h of milling, a solid solution of Al-Mg-Si with a grain size of ~ 40 nm was produced. The as milled and annealed powder was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The microhardness values of alloy increase by increasing MA time. Mg2Si particles precipitate from solid solution during subsequent annealing. The as milled powder appeared to have good thermal stability against grain growth so that the grain size after annealing remained constant (~ 40 nm). When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3486

Comparison of knowledge, attitude and practice of Urban and rural households toward iron deficiency anemia in three provinces of Iran

Background: Lack of nutritional knowledge is one of the most important reasons of nutritional problems and consequently improper practice, which can lead to several complications. This study has been designed in order to compare knowledge, attitude and practices of the urban and rural households regarding iron deficiency anemia (IDA) in Boushehr, Golestan and Sistan & Balouchestan provinces in 2004. Methods: The sampling method at household's level in each province was the single-stage cluster sampling with equal size clusters. The necessary data were gathered with a structured questionnaire and via the interviews between the questioners and the eligible people in each household. Comparison of frequency of variables between urban and rural areas were tested by chi square test. Results: A total of 2306 households were selected as overall sample size. In urban areas, people recognized iron food sources better than rural areas. Knowledge level of respondents about vulnerable group for IDA and the favorite attitude of households toward IDA were better in urban areas of Sistan & Blouchestan and Golestan provinces. In Sistan & Balouchestan and Golestan, rural households who drank tea immediately before or after meal was more than urban ones. The majority of pregnant and lactating mothers (except for rural areas of Bushehr) did not take iron supplement regularly. Less than 60 percent of children used iron drop regularly. Conclusion: Knowledge, attitude, and practice levels of households toward IDA were not acceptable. One of the best ways of improving nutritional practice is nutritional education with focus on applying available food resources