255 research outputs found

    Potential of Iranian wild barley (Hordeum vulgare ssp. spontaneum) in breeding for drought tolerance

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    The vast genetic resources of wild barley (Hordeum vulgare ssp. spontaneum, hereafter WB) may hold unique assets for improving barley (H. vulgare ssp. vulgare) cultivars for drought stress. To evaluate genetic potential and characterization of variation among a diverse collection of barley and WB genotypes, mostly originated from Iran, a field experiment was performed under three moisture environments (control, mild and intense drought stress) during two years (2012–2014). Considerable variation was observed among the wild and cultivated genotypes for drought tolerance and agronomic traits. Principal component analysis (PCA) grouped genotypes studied into three groups (WB, two-row barley and sixrow barley groups). However, Iranian and foreign WB genotypes were not completely separated, showing a high variation within both gene pools. The high significance of genotype by environment interaction, confirms importance of using accurate target environments for drought stress breeding. A number of WB genotypes with the highest values of the number of tillers, number of seed per spike, seed weight, grain yield and yield stability index under stressed environments were identified as superior genotypes. Most of these genotypes originate from Iran, highlighting the importance of this germplasm in barley breeding

    A Flow Based Horizontal Scan Detection Using Genetic Algorithm Approach

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    Abstract: An attacker has to "scan" susceptible points of a network before attacking. There are several methods of detection of such behavior which are mostly based on thresholding. As the performance of these methods is highly dependent on the value of threshold, it is crucial to adjust this value appropriately. This adjustment is not always trivial. In this study we proposed a new method to optimize the parameters of the system using genetic algorithms (GA) based on network flows. Subsequently we compared our method with Snort. The results showed a superior performance as measured by the sensitivity index of d"

    The role of impulsivity, attentional bias and decision-making styles in risky driving behaviors among male drivers in tehran

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    Background: Road accidents are a major cause of deaths, injuries, and financial losses globally, especially in developing countries. Iran is one of the countries with a high rate of road accidents causing considerable damage in different domains. Therefore, in order to tackle this problem, we need to examine its causes. Objectives: The aim of the present study was to examine the association of risky driving behavior with impulsiveness, attentional bias, and decision-making styles. Methods: Thiswasa descriptive-correlational study. The sample included 117 maledrivers, aged 20-34 years, attending car insurance agencies in Tehran. The participants were selected using the convenience sampling method. The data were gathered using the Manchester Driver Behavior Questionnaire (DBQ), the Barratt Impulsiveness Scale (BIS), the Decision-Making Style Scale (DMS), and the Dot Probe Task to assess attentional bias. All the analyses were performed using SPSS, version 22. Results: According to the results of the Pearson correlation coefficient, risky driving behavior was significantly correlated with impulsiveness subscales (P < 0.01) and attentional bias (P < 0.05). In addition, significant relationships were observed between risky driving behaviors and three decision-making styles, including rational (P < 0.05), spontaneous (P < 0.01), and avoidant (P < 0.01). Conclusions: Based on the study results, impulsivity, decision-making styles, and attentional bias as factors influencing drivers' cognitive skills related to driving, could explain the increase in the frequency of risky driving behavior. © 2020, Author(s)

    SSwWS: structural model of information architecture

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    The Web Technologies allow a representation of a domain of knowledge. This facilitates the conversion of an explicit and tacit knowledge to the possibility of adding knowledge to the Web for automatic processing by the computer. For this reason, it has been designed to be an architecture known as SSwWS (Search Semantic with Web Services) or Search Semantic Web Services, to show how to extend the functionality of the Web search and semantic raised by Berners-Lee, on the meta-references, defined in a Web ontology, so that a user on the Internet can find the answers to their questions through Web services in a simple and fast

    Generating GHZ state in 2m-qubit spin network

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    We consider a pure 2m-qubit initial state to evolve under a particular quantum me- chanical spin Hamiltonian, which can be written in terms of the adjacency matrix of the Johnson network J(2m;m). Then, by using some techniques such as spectral dis- tribution and stratification associated with the graphs, employed in [1, 2], a maximally entangled GHZ state is generated between the antipodes of the network. In fact, an explicit formula is given for the suitable coupling strengths of the hamiltonian, so that a maximally entangled state can be generated between antipodes of the network. By using some known multipartite entanglement measures, the amount of the entanglement of the final evolved state is calculated, and finally two examples of four qubit and six qubit states are considered in details.Comment: 22 page

    Development and psychometric evaluation of the sexual knowledge and attitudes scale for premarital couples (SKAS-PC): An exploratory mixed method study

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    Background: Designing a valid and reliable questionnaire that allows a fair evaluation of sexual knowledge and attitudes and develop a proper sexual educational program is necessary. Objective: The present study was designed to develop and psychometric evaluation of the sexual knowledge and attitudes scale for premarital couples. Materials and Methods: An exploratory mixed method study was conducted in two phases; in the first, in order to develop a questionnaire an item pool was generated on sexual knowledge and attitudes through focus group discussions and individual interviews. In the second phase, the psychometric properties of the questionnaire were examined. For this purpose, face validity, content validity as well as construct validity were conducted. Reliability was assessed by the Cronbach�s alpha coefficient to assess internal consistency and test-retest reliability. Results: In the first phase an item pool with 88 questions was generated (sexual knowledge 45 items and sexual attitudes 43 items). In the second phase, the number of final items reduced to 33 and 34 items of sexual knowledge and sexual attitudes respectively, through exploratory factor analysis (EFA). Five factors for sexual knowledge and six factors for sexual attitudes identified by EFA. The Cronbach�s alpha coefficient for two sections was 0.84 and 0.81 respectively. The test- retest correlations for sexual knowledge and sexual attitude was 0.74 and 0.82 respectively. Conclusion: The findings suggest that the Sexual Knowledge and Attitudes Scale for Premarital Couples is a valid and reliable instrument. Further studies are needed to establish stronger psychometric properties for the questionnaire. © 2018, Research and Clinical Center for Infertitlity. All rights reserved

    A general algorithm for manipulating non-linear and linear entanglement witnesses by using exact convex optimization

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    A generic algorithm is developed to reduce the problem of obtaining linear and nonlinear entanglement witnesses of a given quantum system, to convex optimization problem. This approach is completely general and can be applied for the entanglement detection of any N-partite quantum system. For this purpose, a map from convex space of separable density matrices to a convex region called feasible region is defined, where by using exact convex optimization method, the linear entanglement witnesses can be obtained from polygonal shape feasible regions, while for curved shape feasible regions, envelope of the family of linear entanglement witnesses can be considered as nonlinear entanglement witnesses. This method proposes a new methodological framework within which most of previous EWs can be studied. To conclude and in order to demonstrate the capability of the proposed approach, besides providing some nonlinear witnesses for entanglement detection of density matrices in unextendible product bases, W-states, and GHZ with W-states, some further examples of three qubits systems and their classification and entanglement detection are included. Also it is explained how one can manipulate most of the non-decomposable linear and nonlinear three qubits entanglement witnesses appearing in some of the papers published by us and other authors, by the method proposed in this paper. Keywords: non-linear and linear entanglement witnesses, convex optimization. PACS number(s): 03.67.Mn, 03.65.UdComment: 37 page

    The effect of chrysin�curcumin-loaded nanofibres on the wound-healing process in male rats

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    Aim: The aim of the present study was to produce chrysin�curcumin-loaded PCL-PEG nanofibres by an electrospinning technique and to evaluate the biological activity of the chrysin�curcumin-loaded PCL-PEG fibres for wound healing and its related genes using in vivo methods. Materials and methods: The electrospinning method was carried out for the preparation of the chrysin, curcumin and chrysin�curcumin-loaded PCL-PEG nanofibres with different concentrations. FTIR and SEM were performed to characterize the chemical structures and morphology of the nanofibres. In vitro drug release, as well as in vivo wound-healing studies were investigated in male rats. The expressions of genes related to the wound-healing process were also evaluated by real-time PCR. Results: Our study showed that the chrysin�curcumin-loaded nanofibres have anti-inflammatory properties in several stages of the wound-healing process by affecting the IL-6, MMP-2, TIMP-1, TIMP-2 and iNOS gene expression. Our results demonstrated that the effect of the chrysin-loaded nanofibre, the curcumin-loaded nanofibre and the chrysin�curcumin-loaded nanofibre in the wound-healing process is dose dependent and in accordance with the obtained results in that it might affect the inflammation phase more than the other stages of the wound-healing process. Conclusion: We have introduced chrysin�curcumin-loaded PCL-PEG nanofibres as a novel compound for shortening the duration of the wound-healing process. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

    Electron quantum metamaterials in van der Waals heterostructures

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    In recent decades, scientists have developed the means to engineer synthetic periodic arrays with feature sizes below the wavelength of light. When such features are appropriately structured, electromagnetic radiation can be manipulated in unusual ways, resulting in optical metamaterials whose function is directly controlled through nanoscale structure. Nature, too, has adopted such techniques -- for example in the unique coloring of butterfly wings -- to manipulate photons as they propagate through nanoscale periodic assemblies. In this Perspective, we highlight the intriguing potential of designer sub-electron wavelength (as well as wavelength-scale) structuring of electronic matter, which affords a new range of synthetic quantum metamaterials with unconventional responses. Driven by experimental developments in stacking atomically layered heterostructures -- e.g., mechanical pick-up/transfer assembly -- atomic scale registrations and structures can be readily tuned over distances smaller than characteristic electronic length-scales (such as electron wavelength, screening length, and electron mean free path). Yet electronic metamaterials promise far richer categories of behavior than those found in conventional optical metamaterial technologies. This is because unlike photons that scarcely interact with each other, electrons in subwavelength structured metamaterials are charged, and strongly interact. As a result, an enormous variety of emergent phenomena can be expected, and radically new classes of interacting quantum metamaterials designed

    Frequency and outcome of olfactory impairment and sinonasal involvement in hospitalized patients with COVID-19

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    Background: Olfactory dysfunction has shown to accompany COVID-19. There are varying data regarding the exact frequency in the various study population. The outcome of the olfactory impairment is also not clearly defined. Objective: To find the frequency of olfactory impairment and its outcome in hospitalized patients with positive swab test for COVID-19. Methods: This is a prospective descriptive study of 100 hospitalized COVID-19 patients, randomly sampled, from February to March 2020. Demographics, comorbidities, and laboratory findings were analyzed according to the olfactory loss or sinonasal symptoms. The olfactory impairment and sinonasal symptoms were evaluated by 9 Likert scale questions asked from the patients. Results: Ninety-two patients completed the follow-up (means 20.1 (± 7.42) days). Twenty-two (23.91) patients complained of olfactory loss and in 6 (6.52) patients olfactory loss was the first symptom of the disease. The olfactory loss was reported to be completely resolved in all but one patient. Thirty-nine (42.39) patients had notable sinonasal symptoms while rhinorrhea was the first symptom in 3 (3.26). Fifteen patients (16.3) had a taste impairment. Patients with sinonasal symptoms had a lower age (p = 0.01). There was no significant relation between olfactory loss and sinonasal symptoms (p = 0.07). Conclusions: Sudden olfactory dysfunction and sinonasal symptoms have a considerable prevalence in patients with COVID-19. No significant association was noted between the sinonasal symptoms and the olfactory loss, which may suggest that other mechanisms beyond upper respiratory tract involvement are responsible for the olfactory loss. © 2020, Fondazione Società Italiana di Neurologia
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